mirror of https://gitee.com/openkylin/linux.git
2917 lines
74 KiB
C
2917 lines
74 KiB
C
#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/spinlock.h>
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#include <linux/list.h>
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/debugfs.h>
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#include <linux/seq_file.h>
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#include <linux/gpio.h>
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#include <linux/of_gpio.h>
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#include <linux/idr.h>
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#include <linux/slab.h>
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#include <linux/acpi.h>
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#include <linux/gpio/driver.h>
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#include "gpiolib.h"
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#define CREATE_TRACE_POINTS
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#include <trace/events/gpio.h>
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/* Implementation infrastructure for GPIO interfaces.
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*
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* The GPIO programming interface allows for inlining speed-critical
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* get/set operations for common cases, so that access to SOC-integrated
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* GPIOs can sometimes cost only an instruction or two per bit.
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*/
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/* When debugging, extend minimal trust to callers and platform code.
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* Also emit diagnostic messages that may help initial bringup, when
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* board setup or driver bugs are most common.
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*
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* Otherwise, minimize overhead in what may be bitbanging codepaths.
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*/
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#ifdef DEBUG
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#define extra_checks 1
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#else
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#define extra_checks 0
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#endif
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/* gpio_lock prevents conflicts during gpio_desc[] table updates.
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* While any GPIO is requested, its gpio_chip is not removable;
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* each GPIO's "requested" flag serves as a lock and refcount.
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*/
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static DEFINE_SPINLOCK(gpio_lock);
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struct gpio_desc {
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struct gpio_chip *chip;
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unsigned long flags;
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/* flag symbols are bit numbers */
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#define FLAG_REQUESTED 0
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#define FLAG_IS_OUT 1
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#define FLAG_EXPORT 2 /* protected by sysfs_lock */
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#define FLAG_SYSFS 3 /* exported via /sys/class/gpio/control */
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#define FLAG_TRIG_FALL 4 /* trigger on falling edge */
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#define FLAG_TRIG_RISE 5 /* trigger on rising edge */
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#define FLAG_ACTIVE_LOW 6 /* value has active low */
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#define FLAG_OPEN_DRAIN 7 /* Gpio is open drain type */
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#define FLAG_OPEN_SOURCE 8 /* Gpio is open source type */
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#define FLAG_USED_AS_IRQ 9 /* GPIO is connected to an IRQ */
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#define ID_SHIFT 16 /* add new flags before this one */
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#define GPIO_FLAGS_MASK ((1 << ID_SHIFT) - 1)
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#define GPIO_TRIGGER_MASK (BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE))
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#ifdef CONFIG_DEBUG_FS
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const char *label;
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#endif
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};
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static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
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#define GPIO_OFFSET_VALID(chip, offset) (offset >= 0 && offset < chip->ngpio)
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static DEFINE_MUTEX(gpio_lookup_lock);
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static LIST_HEAD(gpio_lookup_list);
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static LIST_HEAD(gpio_chips);
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#ifdef CONFIG_GPIO_SYSFS
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static DEFINE_IDR(dirent_idr);
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#endif
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static int gpiod_request(struct gpio_desc *desc, const char *label);
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static void gpiod_free(struct gpio_desc *desc);
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/* With descriptor prefix */
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#ifdef CONFIG_DEBUG_FS
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#define gpiod_emerg(desc, fmt, ...) \
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pr_emerg("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
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##__VA_ARGS__)
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#define gpiod_crit(desc, fmt, ...) \
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pr_crit("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_err(desc, fmt, ...) \
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pr_err("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_warn(desc, fmt, ...) \
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pr_warn("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_info(desc, fmt, ...) \
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pr_info("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?", \
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##__VA_ARGS__)
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#define gpiod_dbg(desc, fmt, ...) \
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pr_debug("gpio-%d (%s): " fmt, desc_to_gpio(desc), desc->label ? : "?",\
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##__VA_ARGS__)
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#else
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#define gpiod_emerg(desc, fmt, ...) \
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pr_emerg("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#define gpiod_crit(desc, fmt, ...) \
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pr_crit("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#define gpiod_err(desc, fmt, ...) \
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pr_err("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#define gpiod_warn(desc, fmt, ...) \
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pr_warn("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#define gpiod_info(desc, fmt, ...) \
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pr_info("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#define gpiod_dbg(desc, fmt, ...) \
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pr_debug("gpio-%d: " fmt, desc_to_gpio(desc), ##__VA_ARGS__)
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#endif
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/* With chip prefix */
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#define chip_emerg(chip, fmt, ...) \
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pr_emerg("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_crit(chip, fmt, ...) \
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pr_crit("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_err(chip, fmt, ...) \
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pr_err("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_warn(chip, fmt, ...) \
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pr_warn("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_info(chip, fmt, ...) \
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pr_info("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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#define chip_dbg(chip, fmt, ...) \
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pr_debug("GPIO chip %s: " fmt, chip->label, ##__VA_ARGS__)
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static inline void desc_set_label(struct gpio_desc *d, const char *label)
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{
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#ifdef CONFIG_DEBUG_FS
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d->label = label;
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#endif
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}
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/*
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* Return the GPIO number of the passed descriptor relative to its chip
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*/
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static int gpio_chip_hwgpio(const struct gpio_desc *desc)
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{
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return desc - &desc->chip->desc[0];
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}
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/**
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* Convert a GPIO number to its descriptor
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*/
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struct gpio_desc *gpio_to_desc(unsigned gpio)
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{
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if (WARN(!gpio_is_valid(gpio), "invalid GPIO %d\n", gpio))
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return NULL;
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else
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return &gpio_desc[gpio];
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}
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EXPORT_SYMBOL_GPL(gpio_to_desc);
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/**
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* Get the GPIO descriptor corresponding to the given hw number for this chip.
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*/
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struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
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u16 hwnum)
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{
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if (hwnum >= chip->ngpio)
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return ERR_PTR(-EINVAL);
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return &chip->desc[hwnum];
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}
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EXPORT_SYMBOL_GPL(gpiochip_get_desc);
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/**
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* Convert a GPIO descriptor to the integer namespace.
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* This should disappear in the future but is needed since we still
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* use GPIO numbers for error messages and sysfs nodes
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*/
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int desc_to_gpio(const struct gpio_desc *desc)
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{
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return desc - &gpio_desc[0];
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}
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EXPORT_SYMBOL_GPL(desc_to_gpio);
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/* Warn when drivers omit gpio_request() calls -- legal but ill-advised
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* when setting direction, and otherwise illegal. Until board setup code
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* and drivers use explicit requests everywhere (which won't happen when
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* those calls have no teeth) we can't avoid autorequesting. This nag
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* message should motivate switching to explicit requests... so should
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* the weaker cleanup after faults, compared to gpio_request().
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*
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* NOTE: the autorequest mechanism is going away; at this point it's
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* only "legal" in the sense that (old) code using it won't break yet,
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* but instead only triggers a WARN() stack dump.
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*/
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static int gpio_ensure_requested(struct gpio_desc *desc)
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{
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const struct gpio_chip *chip = desc->chip;
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const int gpio = desc_to_gpio(desc);
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if (WARN(test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0,
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"autorequest GPIO-%d\n", gpio)) {
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if (!try_module_get(chip->owner)) {
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gpiod_err(desc, "%s: module can't be gotten\n",
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__func__);
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clear_bit(FLAG_REQUESTED, &desc->flags);
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/* lose */
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return -EIO;
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}
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desc_set_label(desc, "[auto]");
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/* caller must chip->request() w/o spinlock */
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if (chip->request)
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return 1;
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}
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return 0;
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}
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/**
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* gpiod_to_chip - Return the GPIO chip to which a GPIO descriptor belongs
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* @desc: descriptor to return the chip of
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*/
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struct gpio_chip *gpiod_to_chip(const struct gpio_desc *desc)
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{
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return desc ? desc->chip : NULL;
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}
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EXPORT_SYMBOL_GPL(gpiod_to_chip);
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/* dynamic allocation of GPIOs, e.g. on a hotplugged device */
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static int gpiochip_find_base(int ngpio)
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{
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struct gpio_chip *chip;
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int base = ARCH_NR_GPIOS - ngpio;
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list_for_each_entry_reverse(chip, &gpio_chips, list) {
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/* found a free space? */
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if (chip->base + chip->ngpio <= base)
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break;
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else
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/* nope, check the space right before the chip */
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base = chip->base - ngpio;
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}
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if (gpio_is_valid(base)) {
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pr_debug("%s: found new base at %d\n", __func__, base);
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return base;
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} else {
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pr_err("%s: cannot find free range\n", __func__);
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return -ENOSPC;
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}
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}
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/**
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* gpiod_get_direction - return the current direction of a GPIO
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* @desc: GPIO to get the direction of
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*
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* Return GPIOF_DIR_IN or GPIOF_DIR_OUT, or an error code in case of error.
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*
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* This function may sleep if gpiod_cansleep() is true.
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*/
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int gpiod_get_direction(const struct gpio_desc *desc)
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{
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struct gpio_chip *chip;
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unsigned offset;
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int status = -EINVAL;
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chip = gpiod_to_chip(desc);
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offset = gpio_chip_hwgpio(desc);
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if (!chip->get_direction)
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return status;
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status = chip->get_direction(chip, offset);
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if (status > 0) {
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/* GPIOF_DIR_IN, or other positive */
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status = 1;
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/* FLAG_IS_OUT is just a cache of the result of get_direction(),
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* so it does not affect constness per se */
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clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
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}
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if (status == 0) {
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/* GPIOF_DIR_OUT */
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set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags);
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}
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return status;
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}
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EXPORT_SYMBOL_GPL(gpiod_get_direction);
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#ifdef CONFIG_GPIO_SYSFS
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/* lock protects against unexport_gpio() being called while
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* sysfs files are active.
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*/
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static DEFINE_MUTEX(sysfs_lock);
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/*
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* /sys/class/gpio/gpioN... only for GPIOs that are exported
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* /direction
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* * MAY BE OMITTED if kernel won't allow direction changes
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* * is read/write as "in" or "out"
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* * may also be written as "high" or "low", initializing
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* output value as specified ("out" implies "low")
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* /value
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* * always readable, subject to hardware behavior
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* * may be writable, as zero/nonzero
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* /edge
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* * configures behavior of poll(2) on /value
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* * available only if pin can generate IRQs on input
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* * is read/write as "none", "falling", "rising", or "both"
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* /active_low
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* * configures polarity of /value
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* * is read/write as zero/nonzero
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* * also affects existing and subsequent "falling" and "rising"
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* /edge configuration
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*/
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static ssize_t gpio_direction_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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const struct gpio_desc *desc = dev_get_drvdata(dev);
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ssize_t status;
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mutex_lock(&sysfs_lock);
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if (!test_bit(FLAG_EXPORT, &desc->flags)) {
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status = -EIO;
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} else {
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gpiod_get_direction(desc);
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status = sprintf(buf, "%s\n",
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test_bit(FLAG_IS_OUT, &desc->flags)
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? "out" : "in");
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}
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mutex_unlock(&sysfs_lock);
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return status;
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}
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static ssize_t gpio_direction_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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ssize_t status;
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mutex_lock(&sysfs_lock);
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if (!test_bit(FLAG_EXPORT, &desc->flags))
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status = -EIO;
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else if (sysfs_streq(buf, "high"))
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status = gpiod_direction_output_raw(desc, 1);
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else if (sysfs_streq(buf, "out") || sysfs_streq(buf, "low"))
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status = gpiod_direction_output_raw(desc, 0);
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else if (sysfs_streq(buf, "in"))
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status = gpiod_direction_input(desc);
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else
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status = -EINVAL;
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mutex_unlock(&sysfs_lock);
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return status ? : size;
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}
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static /* const */ DEVICE_ATTR(direction, 0644,
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gpio_direction_show, gpio_direction_store);
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static ssize_t gpio_value_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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ssize_t status;
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mutex_lock(&sysfs_lock);
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if (!test_bit(FLAG_EXPORT, &desc->flags))
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status = -EIO;
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else
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status = sprintf(buf, "%d\n", gpiod_get_value_cansleep(desc));
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mutex_unlock(&sysfs_lock);
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return status;
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}
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static ssize_t gpio_value_store(struct device *dev,
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struct device_attribute *attr, const char *buf, size_t size)
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{
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struct gpio_desc *desc = dev_get_drvdata(dev);
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ssize_t status;
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mutex_lock(&sysfs_lock);
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if (!test_bit(FLAG_EXPORT, &desc->flags))
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status = -EIO;
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else if (!test_bit(FLAG_IS_OUT, &desc->flags))
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status = -EPERM;
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else {
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long value;
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status = kstrtol(buf, 0, &value);
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if (status == 0) {
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gpiod_set_value_cansleep(desc, value);
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status = size;
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}
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}
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mutex_unlock(&sysfs_lock);
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return status;
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}
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static const DEVICE_ATTR(value, 0644,
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gpio_value_show, gpio_value_store);
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static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
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{
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struct kernfs_node *value_sd = priv;
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sysfs_notify_dirent(value_sd);
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return IRQ_HANDLED;
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}
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static int gpio_setup_irq(struct gpio_desc *desc, struct device *dev,
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unsigned long gpio_flags)
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{
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struct kernfs_node *value_sd;
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unsigned long irq_flags;
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int ret, irq, id;
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if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
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return 0;
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irq = gpiod_to_irq(desc);
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if (irq < 0)
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return -EIO;
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id = desc->flags >> ID_SHIFT;
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value_sd = idr_find(&dirent_idr, id);
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if (value_sd)
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free_irq(irq, value_sd);
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desc->flags &= ~GPIO_TRIGGER_MASK;
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if (!gpio_flags) {
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gpiod_unlock_as_irq(desc);
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ret = 0;
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goto free_id;
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}
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irq_flags = IRQF_SHARED;
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if (test_bit(FLAG_TRIG_FALL, &gpio_flags))
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irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
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IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
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if (test_bit(FLAG_TRIG_RISE, &gpio_flags))
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irq_flags |= test_bit(FLAG_ACTIVE_LOW, &desc->flags) ?
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IRQF_TRIGGER_FALLING : IRQF_TRIGGER_RISING;
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if (!value_sd) {
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value_sd = sysfs_get_dirent(dev->kobj.sd, "value");
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if (!value_sd) {
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ret = -ENODEV;
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goto err_out;
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}
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ret = idr_alloc(&dirent_idr, value_sd, 1, 0, GFP_KERNEL);
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if (ret < 0)
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goto free_sd;
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id = ret;
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desc->flags &= GPIO_FLAGS_MASK;
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desc->flags |= (unsigned long)id << ID_SHIFT;
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if (desc->flags >> ID_SHIFT != id) {
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ret = -ERANGE;
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goto free_id;
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}
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}
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ret = request_any_context_irq(irq, gpio_sysfs_irq, irq_flags,
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"gpiolib", value_sd);
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if (ret < 0)
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goto free_id;
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ret = gpiod_lock_as_irq(desc);
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if (ret < 0) {
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gpiod_warn(desc, "failed to flag the GPIO for IRQ\n");
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goto free_id;
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}
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desc->flags |= gpio_flags;
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return 0;
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free_id:
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idr_remove(&dirent_idr, id);
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desc->flags &= GPIO_FLAGS_MASK;
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free_sd:
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if (value_sd)
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sysfs_put(value_sd);
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err_out:
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return ret;
|
|
}
|
|
|
|
static const struct {
|
|
const char *name;
|
|
unsigned long flags;
|
|
} trigger_types[] = {
|
|
{ "none", 0 },
|
|
{ "falling", BIT(FLAG_TRIG_FALL) },
|
|
{ "rising", BIT(FLAG_TRIG_RISE) },
|
|
{ "both", BIT(FLAG_TRIG_FALL) | BIT(FLAG_TRIG_RISE) },
|
|
};
|
|
|
|
static ssize_t gpio_edge_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
const struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
ssize_t status;
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
status = -EIO;
|
|
else {
|
|
int i;
|
|
|
|
status = 0;
|
|
for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
|
|
if ((desc->flags & GPIO_TRIGGER_MASK)
|
|
== trigger_types[i].flags) {
|
|
status = sprintf(buf, "%s\n",
|
|
trigger_types[i].name);
|
|
break;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
return status;
|
|
}
|
|
|
|
static ssize_t gpio_edge_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
{
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
ssize_t status;
|
|
int i;
|
|
|
|
for (i = 0; i < ARRAY_SIZE(trigger_types); i++)
|
|
if (sysfs_streq(trigger_types[i].name, buf))
|
|
goto found;
|
|
return -EINVAL;
|
|
|
|
found:
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
status = -EIO;
|
|
else {
|
|
status = gpio_setup_irq(desc, dev, trigger_types[i].flags);
|
|
if (!status)
|
|
status = size;
|
|
}
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
}
|
|
|
|
static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
|
|
|
|
static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
|
|
int value)
|
|
{
|
|
int status = 0;
|
|
|
|
if (!!test_bit(FLAG_ACTIVE_LOW, &desc->flags) == !!value)
|
|
return 0;
|
|
|
|
if (value)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
else
|
|
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
|
|
/* reconfigure poll(2) support if enabled on one edge only */
|
|
if (dev != NULL && (!!test_bit(FLAG_TRIG_RISE, &desc->flags) ^
|
|
!!test_bit(FLAG_TRIG_FALL, &desc->flags))) {
|
|
unsigned long trigger_flags = desc->flags & GPIO_TRIGGER_MASK;
|
|
|
|
gpio_setup_irq(desc, dev, 0);
|
|
status = gpio_setup_irq(desc, dev, trigger_flags);
|
|
}
|
|
|
|
return status;
|
|
}
|
|
|
|
static ssize_t gpio_active_low_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
const struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
ssize_t status;
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags))
|
|
status = -EIO;
|
|
else
|
|
status = sprintf(buf, "%d\n",
|
|
!!test_bit(FLAG_ACTIVE_LOW, &desc->flags));
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status;
|
|
}
|
|
|
|
static ssize_t gpio_active_low_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t size)
|
|
{
|
|
struct gpio_desc *desc = dev_get_drvdata(dev);
|
|
ssize_t status;
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (!test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
status = -EIO;
|
|
} else {
|
|
long value;
|
|
|
|
status = kstrtol(buf, 0, &value);
|
|
if (status == 0)
|
|
status = sysfs_set_active_low(desc, dev, value != 0);
|
|
}
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
return status ? : size;
|
|
}
|
|
|
|
static const DEVICE_ATTR(active_low, 0644,
|
|
gpio_active_low_show, gpio_active_low_store);
|
|
|
|
static const struct attribute *gpio_attrs[] = {
|
|
&dev_attr_value.attr,
|
|
&dev_attr_active_low.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group gpio_attr_group = {
|
|
.attrs = (struct attribute **) gpio_attrs,
|
|
};
|
|
|
|
/*
|
|
* /sys/class/gpio/gpiochipN/
|
|
* /base ... matching gpio_chip.base (N)
|
|
* /label ... matching gpio_chip.label
|
|
* /ngpio ... matching gpio_chip.ngpio
|
|
*/
|
|
|
|
static ssize_t chip_base_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
return sprintf(buf, "%d\n", chip->base);
|
|
}
|
|
static DEVICE_ATTR(base, 0444, chip_base_show, NULL);
|
|
|
|
static ssize_t chip_label_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
return sprintf(buf, "%s\n", chip->label ? : "");
|
|
}
|
|
static DEVICE_ATTR(label, 0444, chip_label_show, NULL);
|
|
|
|
static ssize_t chip_ngpio_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
const struct gpio_chip *chip = dev_get_drvdata(dev);
|
|
|
|
return sprintf(buf, "%u\n", chip->ngpio);
|
|
}
|
|
static DEVICE_ATTR(ngpio, 0444, chip_ngpio_show, NULL);
|
|
|
|
static const struct attribute *gpiochip_attrs[] = {
|
|
&dev_attr_base.attr,
|
|
&dev_attr_label.attr,
|
|
&dev_attr_ngpio.attr,
|
|
NULL,
|
|
};
|
|
|
|
static const struct attribute_group gpiochip_attr_group = {
|
|
.attrs = (struct attribute **) gpiochip_attrs,
|
|
};
|
|
|
|
/*
|
|
* /sys/class/gpio/export ... write-only
|
|
* integer N ... number of GPIO to export (full access)
|
|
* /sys/class/gpio/unexport ... write-only
|
|
* integer N ... number of GPIO to unexport
|
|
*/
|
|
static ssize_t export_store(struct class *class,
|
|
struct class_attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
long gpio;
|
|
struct gpio_desc *desc;
|
|
int status;
|
|
|
|
status = kstrtol(buf, 0, &gpio);
|
|
if (status < 0)
|
|
goto done;
|
|
|
|
desc = gpio_to_desc(gpio);
|
|
/* reject invalid GPIOs */
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* No extra locking here; FLAG_SYSFS just signifies that the
|
|
* request and export were done by on behalf of userspace, so
|
|
* they may be undone on its behalf too.
|
|
*/
|
|
|
|
status = gpiod_request(desc, "sysfs");
|
|
if (status < 0) {
|
|
if (status == -EPROBE_DEFER)
|
|
status = -ENODEV;
|
|
goto done;
|
|
}
|
|
status = gpiod_export(desc, true);
|
|
if (status < 0)
|
|
gpiod_free(desc);
|
|
else
|
|
set_bit(FLAG_SYSFS, &desc->flags);
|
|
|
|
done:
|
|
if (status)
|
|
pr_debug("%s: status %d\n", __func__, status);
|
|
return status ? : len;
|
|
}
|
|
|
|
static ssize_t unexport_store(struct class *class,
|
|
struct class_attribute *attr,
|
|
const char *buf, size_t len)
|
|
{
|
|
long gpio;
|
|
struct gpio_desc *desc;
|
|
int status;
|
|
|
|
status = kstrtol(buf, 0, &gpio);
|
|
if (status < 0)
|
|
goto done;
|
|
|
|
desc = gpio_to_desc(gpio);
|
|
/* reject bogus commands (gpio_unexport ignores them) */
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO %ld\n", __func__, gpio);
|
|
return -EINVAL;
|
|
}
|
|
|
|
status = -EINVAL;
|
|
|
|
/* No extra locking here; FLAG_SYSFS just signifies that the
|
|
* request and export were done by on behalf of userspace, so
|
|
* they may be undone on its behalf too.
|
|
*/
|
|
if (test_and_clear_bit(FLAG_SYSFS, &desc->flags)) {
|
|
status = 0;
|
|
gpiod_free(desc);
|
|
}
|
|
done:
|
|
if (status)
|
|
pr_debug("%s: status %d\n", __func__, status);
|
|
return status ? : len;
|
|
}
|
|
|
|
static struct class_attribute gpio_class_attrs[] = {
|
|
__ATTR(export, 0200, NULL, export_store),
|
|
__ATTR(unexport, 0200, NULL, unexport_store),
|
|
__ATTR_NULL,
|
|
};
|
|
|
|
static struct class gpio_class = {
|
|
.name = "gpio",
|
|
.owner = THIS_MODULE,
|
|
|
|
.class_attrs = gpio_class_attrs,
|
|
};
|
|
|
|
|
|
/**
|
|
* gpiod_export - export a GPIO through sysfs
|
|
* @gpio: gpio to make available, already requested
|
|
* @direction_may_change: true if userspace may change gpio direction
|
|
* Context: arch_initcall or later
|
|
*
|
|
* When drivers want to make a GPIO accessible to userspace after they
|
|
* have requested it -- perhaps while debugging, or as part of their
|
|
* public interface -- they may use this routine. If the GPIO can
|
|
* change direction (some can't) and the caller allows it, userspace
|
|
* will see "direction" sysfs attribute which may be used to change
|
|
* the gpio's direction. A "value" attribute will always be provided.
|
|
*
|
|
* Returns zero on success, else an error.
|
|
*/
|
|
int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
|
|
{
|
|
unsigned long flags;
|
|
int status;
|
|
const char *ioname = NULL;
|
|
struct device *dev;
|
|
int offset;
|
|
|
|
/* can't export until sysfs is available ... */
|
|
if (!gpio_class.p) {
|
|
pr_debug("%s: called too early!\n", __func__);
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (!desc) {
|
|
pr_debug("%s: invalid gpio descriptor\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
if (!test_bit(FLAG_REQUESTED, &desc->flags) ||
|
|
test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
gpiod_dbg(desc, "%s: unavailable (requested=%d, exported=%d)\n",
|
|
__func__,
|
|
test_bit(FLAG_REQUESTED, &desc->flags),
|
|
test_bit(FLAG_EXPORT, &desc->flags));
|
|
status = -EPERM;
|
|
goto fail_unlock;
|
|
}
|
|
|
|
if (!desc->chip->direction_input || !desc->chip->direction_output)
|
|
direction_may_change = false;
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (desc->chip->names && desc->chip->names[offset])
|
|
ioname = desc->chip->names[offset];
|
|
|
|
dev = device_create(&gpio_class, desc->chip->dev, MKDEV(0, 0),
|
|
desc, ioname ? ioname : "gpio%u",
|
|
desc_to_gpio(desc));
|
|
if (IS_ERR(dev)) {
|
|
status = PTR_ERR(dev);
|
|
goto fail_unlock;
|
|
}
|
|
|
|
status = sysfs_create_group(&dev->kobj, &gpio_attr_group);
|
|
if (status)
|
|
goto fail_unregister_device;
|
|
|
|
if (direction_may_change) {
|
|
status = device_create_file(dev, &dev_attr_direction);
|
|
if (status)
|
|
goto fail_unregister_device;
|
|
}
|
|
|
|
if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
|
|
!test_bit(FLAG_IS_OUT, &desc->flags))) {
|
|
status = device_create_file(dev, &dev_attr_edge);
|
|
if (status)
|
|
goto fail_unregister_device;
|
|
}
|
|
|
|
set_bit(FLAG_EXPORT, &desc->flags);
|
|
mutex_unlock(&sysfs_lock);
|
|
return 0;
|
|
|
|
fail_unregister_device:
|
|
device_unregister(dev);
|
|
fail_unlock:
|
|
mutex_unlock(&sysfs_lock);
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_export);
|
|
|
|
static int match_export(struct device *dev, const void *data)
|
|
{
|
|
return dev_get_drvdata(dev) == data;
|
|
}
|
|
|
|
/**
|
|
* gpiod_export_link - create a sysfs link to an exported GPIO node
|
|
* @dev: device under which to create symlink
|
|
* @name: name of the symlink
|
|
* @gpio: gpio to create symlink to, already exported
|
|
*
|
|
* Set up a symlink from /sys/.../dev/name to /sys/class/gpio/gpioN
|
|
* node. Caller is responsible for unlinking.
|
|
*
|
|
* Returns zero on success, else an error.
|
|
*/
|
|
int gpiod_export_link(struct device *dev, const char *name,
|
|
struct gpio_desc *desc)
|
|
{
|
|
int status = -EINVAL;
|
|
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
struct device *tdev;
|
|
|
|
tdev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
if (tdev != NULL) {
|
|
status = sysfs_create_link(&dev->kobj, &tdev->kobj,
|
|
name);
|
|
} else {
|
|
status = -ENODEV;
|
|
}
|
|
}
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_export_link);
|
|
|
|
/**
|
|
* gpiod_sysfs_set_active_low - set the polarity of gpio sysfs value
|
|
* @gpio: gpio to change
|
|
* @value: non-zero to use active low, i.e. inverted values
|
|
*
|
|
* Set the polarity of /sys/class/gpio/gpioN/value sysfs attribute.
|
|
* The GPIO does not have to be exported yet. If poll(2) support has
|
|
* been enabled for either rising or falling edge, it will be
|
|
* reconfigured to follow the new polarity.
|
|
*
|
|
* Returns zero on success, else an error.
|
|
*/
|
|
int gpiod_sysfs_set_active_low(struct gpio_desc *desc, int value)
|
|
{
|
|
struct device *dev = NULL;
|
|
int status = -EINVAL;
|
|
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
dev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
if (dev == NULL) {
|
|
status = -ENODEV;
|
|
goto unlock;
|
|
}
|
|
}
|
|
|
|
status = sysfs_set_active_low(desc, dev, value);
|
|
|
|
unlock:
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_sysfs_set_active_low);
|
|
|
|
/**
|
|
* gpiod_unexport - reverse effect of gpio_export()
|
|
* @gpio: gpio to make unavailable
|
|
*
|
|
* This is implicit on gpio_free().
|
|
*/
|
|
void gpiod_unexport(struct gpio_desc *desc)
|
|
{
|
|
int status = 0;
|
|
struct device *dev = NULL;
|
|
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return;
|
|
}
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
|
|
if (test_bit(FLAG_EXPORT, &desc->flags)) {
|
|
|
|
dev = class_find_device(&gpio_class, NULL, desc, match_export);
|
|
if (dev) {
|
|
gpio_setup_irq(desc, dev, 0);
|
|
clear_bit(FLAG_EXPORT, &desc->flags);
|
|
} else
|
|
status = -ENODEV;
|
|
}
|
|
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
if (dev) {
|
|
device_unregister(dev);
|
|
put_device(dev);
|
|
}
|
|
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_unexport);
|
|
|
|
static int gpiochip_export(struct gpio_chip *chip)
|
|
{
|
|
int status;
|
|
struct device *dev;
|
|
|
|
/* Many systems register gpio chips for SOC support very early,
|
|
* before driver model support is available. In those cases we
|
|
* export this later, in gpiolib_sysfs_init() ... here we just
|
|
* verify that _some_ field of gpio_class got initialized.
|
|
*/
|
|
if (!gpio_class.p)
|
|
return 0;
|
|
|
|
/* use chip->base for the ID; it's already known to be unique */
|
|
mutex_lock(&sysfs_lock);
|
|
dev = device_create(&gpio_class, chip->dev, MKDEV(0, 0), chip,
|
|
"gpiochip%d", chip->base);
|
|
if (!IS_ERR(dev)) {
|
|
status = sysfs_create_group(&dev->kobj,
|
|
&gpiochip_attr_group);
|
|
} else
|
|
status = PTR_ERR(dev);
|
|
chip->exported = (status == 0);
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
if (status) {
|
|
unsigned long flags;
|
|
unsigned gpio;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
gpio = 0;
|
|
while (gpio < chip->ngpio)
|
|
chip->desc[gpio++].chip = NULL;
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
chip_dbg(chip, "%s: status %d\n", __func__, status);
|
|
}
|
|
|
|
return status;
|
|
}
|
|
|
|
static void gpiochip_unexport(struct gpio_chip *chip)
|
|
{
|
|
int status;
|
|
struct device *dev;
|
|
|
|
mutex_lock(&sysfs_lock);
|
|
dev = class_find_device(&gpio_class, NULL, chip, match_export);
|
|
if (dev) {
|
|
put_device(dev);
|
|
device_unregister(dev);
|
|
chip->exported = false;
|
|
status = 0;
|
|
} else
|
|
status = -ENODEV;
|
|
mutex_unlock(&sysfs_lock);
|
|
|
|
if (status)
|
|
chip_dbg(chip, "%s: status %d\n", __func__, status);
|
|
}
|
|
|
|
static int __init gpiolib_sysfs_init(void)
|
|
{
|
|
int status;
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
|
|
status = class_register(&gpio_class);
|
|
if (status < 0)
|
|
return status;
|
|
|
|
/* Scan and register the gpio_chips which registered very
|
|
* early (e.g. before the class_register above was called).
|
|
*
|
|
* We run before arch_initcall() so chip->dev nodes can have
|
|
* registered, and so arch_initcall() can always gpio_export().
|
|
*/
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(chip, &gpio_chips, list) {
|
|
if (!chip || chip->exported)
|
|
continue;
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
status = gpiochip_export(chip);
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
|
|
return status;
|
|
}
|
|
postcore_initcall(gpiolib_sysfs_init);
|
|
|
|
#else
|
|
static inline int gpiochip_export(struct gpio_chip *chip)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
static inline void gpiochip_unexport(struct gpio_chip *chip)
|
|
{
|
|
}
|
|
|
|
#endif /* CONFIG_GPIO_SYSFS */
|
|
|
|
/*
|
|
* Add a new chip to the global chips list, keeping the list of chips sorted
|
|
* by base order.
|
|
*
|
|
* Return -EBUSY if the new chip overlaps with some other chip's integer
|
|
* space.
|
|
*/
|
|
static int gpiochip_add_to_list(struct gpio_chip *chip)
|
|
{
|
|
struct list_head *pos = &gpio_chips;
|
|
struct gpio_chip *_chip;
|
|
int err = 0;
|
|
|
|
/* find where to insert our chip */
|
|
list_for_each(pos, &gpio_chips) {
|
|
_chip = list_entry(pos, struct gpio_chip, list);
|
|
/* shall we insert before _chip? */
|
|
if (_chip->base >= chip->base + chip->ngpio)
|
|
break;
|
|
}
|
|
|
|
/* are we stepping on the chip right before? */
|
|
if (pos != &gpio_chips && pos->prev != &gpio_chips) {
|
|
_chip = list_entry(pos->prev, struct gpio_chip, list);
|
|
if (_chip->base + _chip->ngpio > chip->base) {
|
|
dev_err(chip->dev,
|
|
"GPIO integer space overlap, cannot add chip\n");
|
|
err = -EBUSY;
|
|
}
|
|
}
|
|
|
|
if (!err)
|
|
list_add_tail(&chip->list, pos);
|
|
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* gpiochip_add() - register a gpio_chip
|
|
* @chip: the chip to register, with chip->base initialized
|
|
* Context: potentially before irqs or kmalloc will work
|
|
*
|
|
* Returns a negative errno if the chip can't be registered, such as
|
|
* because the chip->base is invalid or already associated with a
|
|
* different chip. Otherwise it returns zero as a success code.
|
|
*
|
|
* When gpiochip_add() is called very early during boot, so that GPIOs
|
|
* can be freely used, the chip->dev device must be registered before
|
|
* the gpio framework's arch_initcall(). Otherwise sysfs initialization
|
|
* for GPIOs will fail rudely.
|
|
*
|
|
* If chip->base is negative, this requests dynamic assignment of
|
|
* a range of valid GPIOs.
|
|
*/
|
|
int gpiochip_add(struct gpio_chip *chip)
|
|
{
|
|
unsigned long flags;
|
|
int status = 0;
|
|
unsigned id;
|
|
int base = chip->base;
|
|
|
|
if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
|
|
&& base >= 0) {
|
|
status = -EINVAL;
|
|
goto fail;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (base < 0) {
|
|
base = gpiochip_find_base(chip->ngpio);
|
|
if (base < 0) {
|
|
status = base;
|
|
goto unlock;
|
|
}
|
|
chip->base = base;
|
|
}
|
|
|
|
status = gpiochip_add_to_list(chip);
|
|
|
|
if (status == 0) {
|
|
chip->desc = &gpio_desc[chip->base];
|
|
|
|
for (id = 0; id < chip->ngpio; id++) {
|
|
struct gpio_desc *desc = &chip->desc[id];
|
|
desc->chip = chip;
|
|
|
|
/* REVISIT: most hardware initializes GPIOs as
|
|
* inputs (often with pullups enabled) so power
|
|
* usage is minimized. Linux code should set the
|
|
* gpio direction first thing; but until it does,
|
|
* and in case chip->get_direction is not set,
|
|
* we may expose the wrong direction in sysfs.
|
|
*/
|
|
desc->flags = !chip->direction_input
|
|
? (1 << FLAG_IS_OUT)
|
|
: 0;
|
|
}
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
INIT_LIST_HEAD(&chip->pin_ranges);
|
|
#endif
|
|
|
|
of_gpiochip_add(chip);
|
|
acpi_gpiochip_add(chip);
|
|
|
|
if (status)
|
|
goto fail;
|
|
|
|
status = gpiochip_export(chip);
|
|
if (status)
|
|
goto fail;
|
|
|
|
pr_debug("%s: registered GPIOs %d to %d on device: %s\n", __func__,
|
|
chip->base, chip->base + chip->ngpio - 1,
|
|
chip->label ? : "generic");
|
|
|
|
return 0;
|
|
|
|
unlock:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
fail:
|
|
/* failures here can mean systems won't boot... */
|
|
pr_err("%s: GPIOs %d..%d (%s) failed to register\n", __func__,
|
|
chip->base, chip->base + chip->ngpio - 1,
|
|
chip->label ? : "generic");
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add);
|
|
|
|
/* Forward-declaration */
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
|
|
|
|
/**
|
|
* gpiochip_remove() - unregister a gpio_chip
|
|
* @chip: the chip to unregister
|
|
*
|
|
* A gpio_chip with any GPIOs still requested may not be removed.
|
|
*/
|
|
int gpiochip_remove(struct gpio_chip *chip)
|
|
{
|
|
unsigned long flags;
|
|
int status = 0;
|
|
unsigned id;
|
|
|
|
acpi_gpiochip_remove(chip);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
gpiochip_irqchip_remove(chip);
|
|
gpiochip_remove_pin_ranges(chip);
|
|
of_gpiochip_remove(chip);
|
|
|
|
for (id = 0; id < chip->ngpio; id++) {
|
|
if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) {
|
|
status = -EBUSY;
|
|
break;
|
|
}
|
|
}
|
|
if (status == 0) {
|
|
for (id = 0; id < chip->ngpio; id++)
|
|
chip->desc[id].chip = NULL;
|
|
|
|
list_del(&chip->list);
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
if (status == 0)
|
|
gpiochip_unexport(chip);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_remove);
|
|
|
|
/**
|
|
* gpiochip_find() - iterator for locating a specific gpio_chip
|
|
* @data: data to pass to match function
|
|
* @callback: Callback function to check gpio_chip
|
|
*
|
|
* Similar to bus_find_device. It returns a reference to a gpio_chip as
|
|
* determined by a user supplied @match callback. The callback should return
|
|
* 0 if the device doesn't match and non-zero if it does. If the callback is
|
|
* non-zero, this function will return to the caller and not iterate over any
|
|
* more gpio_chips.
|
|
*/
|
|
struct gpio_chip *gpiochip_find(void *data,
|
|
int (*match)(struct gpio_chip *chip,
|
|
void *data))
|
|
{
|
|
struct gpio_chip *chip;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(chip, &gpio_chips, list)
|
|
if (match(chip, data))
|
|
break;
|
|
|
|
/* No match? */
|
|
if (&chip->list == &gpio_chips)
|
|
chip = NULL;
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
return chip;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_find);
|
|
|
|
static int gpiochip_match_name(struct gpio_chip *chip, void *data)
|
|
{
|
|
const char *name = data;
|
|
|
|
return !strcmp(chip->label, name);
|
|
}
|
|
|
|
static struct gpio_chip *find_chip_by_name(const char *name)
|
|
{
|
|
return gpiochip_find((void *)name, gpiochip_match_name);
|
|
}
|
|
|
|
#ifdef CONFIG_GPIOLIB_IRQCHIP
|
|
|
|
/*
|
|
* The following is irqchip helper code for gpiochips.
|
|
*/
|
|
|
|
/**
|
|
* gpiochip_add_chained_irqchip() - adds a chained irqchip to a gpiochip
|
|
* @gpiochip: the gpiochip to add the irqchip to
|
|
* @irqchip: the irqchip to add to the gpiochip
|
|
* @parent_irq: the irq number corresponding to the parent IRQ for this
|
|
* chained irqchip
|
|
* @parent_handler: the parent interrupt handler for the accumulated IRQ
|
|
* coming out of the gpiochip
|
|
*/
|
|
void gpiochip_set_chained_irqchip(struct gpio_chip *gpiochip,
|
|
struct irq_chip *irqchip,
|
|
int parent_irq,
|
|
irq_flow_handler_t parent_handler)
|
|
{
|
|
irq_set_chained_handler(parent_irq, parent_handler);
|
|
/*
|
|
* The parent irqchip is already using the chip_data for this
|
|
* irqchip, so our callbacks simply use the handler_data.
|
|
*/
|
|
irq_set_handler_data(parent_irq, gpiochip);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_set_chained_irqchip);
|
|
|
|
/**
|
|
* gpiochip_irq_map() - maps an IRQ into a GPIO irqchip
|
|
* @d: the irqdomain used by this irqchip
|
|
* @irq: the global irq number used by this GPIO irqchip irq
|
|
* @hwirq: the local IRQ/GPIO line offset on this gpiochip
|
|
*
|
|
* This function will set up the mapping for a certain IRQ line on a
|
|
* gpiochip by assigning the gpiochip as chip data, and using the irqchip
|
|
* stored inside the gpiochip.
|
|
*/
|
|
static int gpiochip_irq_map(struct irq_domain *d, unsigned int irq,
|
|
irq_hw_number_t hwirq)
|
|
{
|
|
struct gpio_chip *chip = d->host_data;
|
|
|
|
irq_set_chip_data(irq, chip);
|
|
irq_set_chip_and_handler(irq, chip->irqchip, chip->irq_handler);
|
|
#ifdef CONFIG_ARM
|
|
set_irq_flags(irq, IRQF_VALID);
|
|
#else
|
|
irq_set_noprobe(irq);
|
|
#endif
|
|
irq_set_irq_type(irq, chip->irq_default_type);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irq_unmap(struct irq_domain *d, unsigned int irq)
|
|
{
|
|
#ifdef CONFIG_ARM
|
|
set_irq_flags(irq, 0);
|
|
#endif
|
|
irq_set_chip_and_handler(irq, NULL, NULL);
|
|
irq_set_chip_data(irq, NULL);
|
|
}
|
|
|
|
static const struct irq_domain_ops gpiochip_domain_ops = {
|
|
.map = gpiochip_irq_map,
|
|
.unmap = gpiochip_irq_unmap,
|
|
/* Virtually all GPIO irqchips are twocell:ed */
|
|
.xlate = irq_domain_xlate_twocell,
|
|
};
|
|
|
|
static int gpiochip_irq_reqres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
if (gpio_lock_as_irq(chip, d->hwirq)) {
|
|
chip_err(chip,
|
|
"unable to lock HW IRQ %lu for IRQ\n",
|
|
d->hwirq);
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void gpiochip_irq_relres(struct irq_data *d)
|
|
{
|
|
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
|
|
|
|
gpio_unlock_as_irq(chip, d->hwirq);
|
|
}
|
|
|
|
static int gpiochip_to_irq(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
return irq_find_mapping(chip->irqdomain, offset);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_remove() - removes an irqchip added to a gpiochip
|
|
* @gpiochip: the gpiochip to remove the irqchip from
|
|
*
|
|
* This is called only from gpiochip_remove()
|
|
*/
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip)
|
|
{
|
|
unsigned int offset;
|
|
|
|
/* Remove all IRQ mappings and delete the domain */
|
|
if (gpiochip->irqdomain) {
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++)
|
|
irq_dispose_mapping(gpiochip->irq_base + offset);
|
|
irq_domain_remove(gpiochip->irqdomain);
|
|
}
|
|
|
|
if (gpiochip->irqchip) {
|
|
gpiochip->irqchip->irq_request_resources = NULL;
|
|
gpiochip->irqchip->irq_release_resources = NULL;
|
|
gpiochip->irqchip = NULL;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gpiochip_irqchip_add() - adds an irqchip to a gpiochip
|
|
* @gpiochip: the gpiochip to add the irqchip to
|
|
* @irqchip: the irqchip to add to the gpiochip
|
|
* @first_irq: if not dynamically assigned, the base (first) IRQ to
|
|
* allocate gpiochip irqs from
|
|
* @handler: the irq handler to use (often a predefined irq core function)
|
|
* @type: the default type for IRQs on this irqchip
|
|
*
|
|
* This function closely associates a certain irqchip with a certain
|
|
* gpiochip, providing an irq domain to translate the local IRQs to
|
|
* global irqs in the gpiolib core, and making sure that the gpiochip
|
|
* is passed as chip data to all related functions. Driver callbacks
|
|
* need to use container_of() to get their local state containers back
|
|
* from the gpiochip passed as chip data. An irqdomain will be stored
|
|
* in the gpiochip that shall be used by the driver to handle IRQ number
|
|
* translation. The gpiochip will need to be initialized and registered
|
|
* before calling this function.
|
|
*
|
|
* This function will handle two cell:ed simple IRQs and assumes all
|
|
* the pins on the gpiochip can generate a unique IRQ. Everything else
|
|
* need to be open coded.
|
|
*/
|
|
int gpiochip_irqchip_add(struct gpio_chip *gpiochip,
|
|
struct irq_chip *irqchip,
|
|
unsigned int first_irq,
|
|
irq_flow_handler_t handler,
|
|
unsigned int type)
|
|
{
|
|
struct device_node *of_node;
|
|
unsigned int offset;
|
|
unsigned irq_base = 0;
|
|
|
|
if (!gpiochip || !irqchip)
|
|
return -EINVAL;
|
|
|
|
if (!gpiochip->dev) {
|
|
pr_err("missing gpiochip .dev parent pointer\n");
|
|
return -EINVAL;
|
|
}
|
|
of_node = gpiochip->dev->of_node;
|
|
#ifdef CONFIG_OF_GPIO
|
|
/*
|
|
* If the gpiochip has an assigned OF node this takes precendence
|
|
* FIXME: get rid of this and use gpiochip->dev->of_node everywhere
|
|
*/
|
|
if (gpiochip->of_node)
|
|
of_node = gpiochip->of_node;
|
|
#endif
|
|
gpiochip->irqchip = irqchip;
|
|
gpiochip->irq_handler = handler;
|
|
gpiochip->irq_default_type = type;
|
|
gpiochip->to_irq = gpiochip_to_irq;
|
|
gpiochip->irqdomain = irq_domain_add_simple(of_node,
|
|
gpiochip->ngpio, first_irq,
|
|
&gpiochip_domain_ops, gpiochip);
|
|
if (!gpiochip->irqdomain) {
|
|
gpiochip->irqchip = NULL;
|
|
return -EINVAL;
|
|
}
|
|
irqchip->irq_request_resources = gpiochip_irq_reqres;
|
|
irqchip->irq_release_resources = gpiochip_irq_relres;
|
|
|
|
/*
|
|
* Prepare the mapping since the irqchip shall be orthogonal to
|
|
* any gpiochip calls. If the first_irq was zero, this is
|
|
* necessary to allocate descriptors for all IRQs.
|
|
*/
|
|
for (offset = 0; offset < gpiochip->ngpio; offset++) {
|
|
irq_base = irq_create_mapping(gpiochip->irqdomain, offset);
|
|
if (offset == 0)
|
|
/*
|
|
* Store the base into the gpiochip to be used when
|
|
* unmapping the irqs.
|
|
*/
|
|
gpiochip->irq_base = irq_base;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_irqchip_add);
|
|
|
|
#else /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
|
|
|
|
#endif /* CONFIG_GPIOLIB_IRQCHIP */
|
|
|
|
#ifdef CONFIG_PINCTRL
|
|
|
|
/**
|
|
* gpiochip_add_pingroup_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pinctrl: the dev_name() of the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_group: name of the pin group inside the pin controller
|
|
*/
|
|
int gpiochip_add_pingroup_range(struct gpio_chip *chip,
|
|
struct pinctrl_dev *pctldev,
|
|
unsigned int gpio_offset, const char *pin_group)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = chip->base + gpio_offset;
|
|
pin_range->pctldev = pctldev;
|
|
|
|
ret = pinctrl_get_group_pins(pctldev, pin_group,
|
|
&pin_range->range.pins,
|
|
&pin_range->range.npins);
|
|
if (ret < 0) {
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
|
|
pinctrl_add_gpio_range(pctldev, &pin_range->range);
|
|
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PINGRP %s\n",
|
|
gpio_offset, gpio_offset + pin_range->range.npins - 1,
|
|
pinctrl_dev_get_devname(pctldev), pin_group);
|
|
|
|
list_add_tail(&pin_range->node, &chip->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pingroup_range);
|
|
|
|
/**
|
|
* gpiochip_add_pin_range() - add a range for GPIO <-> pin mapping
|
|
* @chip: the gpiochip to add the range for
|
|
* @pinctrl_name: the dev_name() of the pin controller to map to
|
|
* @gpio_offset: the start offset in the current gpio_chip number space
|
|
* @pin_offset: the start offset in the pin controller number space
|
|
* @npins: the number of pins from the offset of each pin space (GPIO and
|
|
* pin controller) to accumulate in this range
|
|
*/
|
|
int gpiochip_add_pin_range(struct gpio_chip *chip, const char *pinctl_name,
|
|
unsigned int gpio_offset, unsigned int pin_offset,
|
|
unsigned int npins)
|
|
{
|
|
struct gpio_pin_range *pin_range;
|
|
int ret;
|
|
|
|
pin_range = kzalloc(sizeof(*pin_range), GFP_KERNEL);
|
|
if (!pin_range) {
|
|
chip_err(chip, "failed to allocate pin ranges\n");
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Use local offset as range ID */
|
|
pin_range->range.id = gpio_offset;
|
|
pin_range->range.gc = chip;
|
|
pin_range->range.name = chip->label;
|
|
pin_range->range.base = chip->base + gpio_offset;
|
|
pin_range->range.pin_base = pin_offset;
|
|
pin_range->range.npins = npins;
|
|
pin_range->pctldev = pinctrl_find_and_add_gpio_range(pinctl_name,
|
|
&pin_range->range);
|
|
if (IS_ERR(pin_range->pctldev)) {
|
|
ret = PTR_ERR(pin_range->pctldev);
|
|
chip_err(chip, "could not create pin range\n");
|
|
kfree(pin_range);
|
|
return ret;
|
|
}
|
|
chip_dbg(chip, "created GPIO range %d->%d ==> %s PIN %d->%d\n",
|
|
gpio_offset, gpio_offset + npins - 1,
|
|
pinctl_name,
|
|
pin_offset, pin_offset + npins - 1);
|
|
|
|
list_add_tail(&pin_range->node, &chip->pin_ranges);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_add_pin_range);
|
|
|
|
/**
|
|
* gpiochip_remove_pin_ranges() - remove all the GPIO <-> pin mappings
|
|
* @chip: the chip to remove all the mappings for
|
|
*/
|
|
void gpiochip_remove_pin_ranges(struct gpio_chip *chip)
|
|
{
|
|
struct gpio_pin_range *pin_range, *tmp;
|
|
|
|
list_for_each_entry_safe(pin_range, tmp, &chip->pin_ranges, node) {
|
|
list_del(&pin_range->node);
|
|
pinctrl_remove_gpio_range(pin_range->pctldev,
|
|
&pin_range->range);
|
|
kfree(pin_range);
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_remove_pin_ranges);
|
|
|
|
#endif /* CONFIG_PINCTRL */
|
|
|
|
/* These "optional" allocation calls help prevent drivers from stomping
|
|
* on each other, and help provide better diagnostics in debugfs.
|
|
* They're called even less than the "set direction" calls.
|
|
*/
|
|
static int __gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
struct gpio_chip *chip = desc->chip;
|
|
int status;
|
|
unsigned long flags;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
/* NOTE: gpio_request() can be called in early boot,
|
|
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
|
|
*/
|
|
|
|
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
|
|
desc_set_label(desc, label ? : "?");
|
|
status = 0;
|
|
} else {
|
|
status = -EBUSY;
|
|
goto done;
|
|
}
|
|
|
|
if (chip->request) {
|
|
/* chip->request may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
status = chip->request(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
if (status < 0) {
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
goto done;
|
|
}
|
|
}
|
|
if (chip->get_direction) {
|
|
/* chip->get_direction may sleep */
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
gpiod_get_direction(desc);
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
done:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return status;
|
|
}
|
|
|
|
static int gpiod_request(struct gpio_desc *desc, const char *label)
|
|
{
|
|
int status = -EPROBE_DEFER;
|
|
struct gpio_chip *chip;
|
|
|
|
if (!desc) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip)
|
|
goto done;
|
|
|
|
if (try_module_get(chip->owner)) {
|
|
status = __gpiod_request(desc, label);
|
|
if (status < 0)
|
|
module_put(chip->owner);
|
|
}
|
|
|
|
done:
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
|
|
int gpio_request(unsigned gpio, const char *label)
|
|
{
|
|
return gpiod_request(gpio_to_desc(gpio), label);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_request);
|
|
|
|
static bool __gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
bool ret = false;
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
|
|
might_sleep();
|
|
|
|
gpiod_unexport(desc);
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
chip = desc->chip;
|
|
if (chip && test_bit(FLAG_REQUESTED, &desc->flags)) {
|
|
if (chip->free) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
might_sleep_if(chip->can_sleep);
|
|
chip->free(chip, gpio_chip_hwgpio(desc));
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
}
|
|
desc_set_label(desc, NULL);
|
|
clear_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
clear_bit(FLAG_REQUESTED, &desc->flags);
|
|
clear_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
clear_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
ret = true;
|
|
}
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return ret;
|
|
}
|
|
|
|
static void gpiod_free(struct gpio_desc *desc)
|
|
{
|
|
if (desc && __gpiod_free(desc))
|
|
module_put(desc->chip->owner);
|
|
else
|
|
WARN_ON(extra_checks);
|
|
}
|
|
|
|
void gpio_free(unsigned gpio)
|
|
{
|
|
gpiod_free(gpio_to_desc(gpio));
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_free);
|
|
|
|
/**
|
|
* gpio_request_one - request a single GPIO with initial configuration
|
|
* @gpio: the GPIO number
|
|
* @flags: GPIO configuration as specified by GPIOF_*
|
|
* @label: a literal description string of this GPIO
|
|
*/
|
|
int gpio_request_one(unsigned gpio, unsigned long flags, const char *label)
|
|
{
|
|
struct gpio_desc *desc;
|
|
int err;
|
|
|
|
desc = gpio_to_desc(gpio);
|
|
|
|
err = gpiod_request(desc, label);
|
|
if (err)
|
|
return err;
|
|
|
|
if (flags & GPIOF_OPEN_DRAIN)
|
|
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
|
|
if (flags & GPIOF_OPEN_SOURCE)
|
|
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
|
|
if (flags & GPIOF_DIR_IN)
|
|
err = gpiod_direction_input(desc);
|
|
else
|
|
err = gpiod_direction_output_raw(desc,
|
|
(flags & GPIOF_INIT_HIGH) ? 1 : 0);
|
|
|
|
if (err)
|
|
goto free_gpio;
|
|
|
|
if (flags & GPIOF_EXPORT) {
|
|
err = gpiod_export(desc, flags & GPIOF_EXPORT_CHANGEABLE);
|
|
if (err)
|
|
goto free_gpio;
|
|
}
|
|
|
|
return 0;
|
|
|
|
free_gpio:
|
|
gpiod_free(desc);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_request_one);
|
|
|
|
/**
|
|
* gpio_request_array - request multiple GPIOs in a single call
|
|
* @array: array of the 'struct gpio'
|
|
* @num: how many GPIOs in the array
|
|
*/
|
|
int gpio_request_array(const struct gpio *array, size_t num)
|
|
{
|
|
int i, err;
|
|
|
|
for (i = 0; i < num; i++, array++) {
|
|
err = gpio_request_one(array->gpio, array->flags, array->label);
|
|
if (err)
|
|
goto err_free;
|
|
}
|
|
return 0;
|
|
|
|
err_free:
|
|
while (i--)
|
|
gpio_free((--array)->gpio);
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_request_array);
|
|
|
|
/**
|
|
* gpio_free_array - release multiple GPIOs in a single call
|
|
* @array: array of the 'struct gpio'
|
|
* @num: how many GPIOs in the array
|
|
*/
|
|
void gpio_free_array(const struct gpio *array, size_t num)
|
|
{
|
|
while (num--)
|
|
gpio_free((array++)->gpio);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_free_array);
|
|
|
|
/**
|
|
* gpiochip_is_requested - return string iff signal was requested
|
|
* @chip: controller managing the signal
|
|
* @offset: of signal within controller's 0..(ngpio - 1) range
|
|
*
|
|
* Returns NULL if the GPIO is not currently requested, else a string.
|
|
* If debugfs support is enabled, the string returned is the label passed
|
|
* to gpio_request(); otherwise it is a meaningless constant.
|
|
*
|
|
* This function is for use by GPIO controller drivers. The label can
|
|
* help with diagnostics, and knowing that the signal is used as a GPIO
|
|
* can help avoid accidentally multiplexing it to another controller.
|
|
*/
|
|
const char *gpiochip_is_requested(struct gpio_chip *chip, unsigned offset)
|
|
{
|
|
struct gpio_desc *desc;
|
|
|
|
if (!GPIO_OFFSET_VALID(chip, offset))
|
|
return NULL;
|
|
|
|
desc = &chip->desc[offset];
|
|
|
|
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
|
|
return NULL;
|
|
#ifdef CONFIG_DEBUG_FS
|
|
return desc->label;
|
|
#else
|
|
return "?";
|
|
#endif
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiochip_is_requested);
|
|
|
|
/**
|
|
* gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor
|
|
* @desc: GPIO descriptor to request
|
|
* @label: label for the GPIO
|
|
*
|
|
* Function allows GPIO chip drivers to request and use their own GPIO
|
|
* descriptors via gpiolib API. Difference to gpiod_request() is that this
|
|
* function will not increase reference count of the GPIO chip module. This
|
|
* allows the GPIO chip module to be unloaded as needed (we assume that the
|
|
* GPIO chip driver handles freeing the GPIOs it has requested).
|
|
*/
|
|
int gpiochip_request_own_desc(struct gpio_desc *desc, const char *label)
|
|
{
|
|
if (!desc || !desc->chip)
|
|
return -EINVAL;
|
|
|
|
return __gpiod_request(desc, label);
|
|
}
|
|
|
|
/**
|
|
* gpiochip_free_own_desc - Free GPIO requested by the chip driver
|
|
* @desc: GPIO descriptor to free
|
|
*
|
|
* Function frees the given GPIO requested previously with
|
|
* gpiochip_request_own_desc().
|
|
*/
|
|
void gpiochip_free_own_desc(struct gpio_desc *desc)
|
|
{
|
|
if (desc)
|
|
__gpiod_free(desc);
|
|
}
|
|
|
|
/* Drivers MUST set GPIO direction before making get/set calls. In
|
|
* some cases this is done in early boot, before IRQs are enabled.
|
|
*
|
|
* As a rule these aren't called more than once (except for drivers
|
|
* using the open-drain emulation idiom) so these are natural places
|
|
* to accumulate extra debugging checks. Note that we can't (yet)
|
|
* rely on gpio_request() having been called beforehand.
|
|
*/
|
|
|
|
/**
|
|
* gpiod_direction_input - set the GPIO direction to input
|
|
* @desc: GPIO to set to input
|
|
*
|
|
* Set the direction of the passed GPIO to input, such as gpiod_get_value() can
|
|
* be called safely on it.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_input(struct gpio_desc *desc)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip->get || !chip->direction_input) {
|
|
gpiod_warn(desc,
|
|
"%s: missing get() or direction_input() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
if (status < 0)
|
|
goto fail;
|
|
|
|
/* now we know the gpio is valid and chip won't vanish */
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
might_sleep_if(chip->can_sleep);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (status) {
|
|
status = chip->request(chip, offset);
|
|
if (status < 0) {
|
|
gpiod_dbg(desc, "%s: chip request fail, %d\n",
|
|
__func__, status);
|
|
/* and it's not available to anyone else ...
|
|
* gpio_request() is the fully clean solution.
|
|
*/
|
|
goto lose;
|
|
}
|
|
}
|
|
|
|
status = chip->direction_input(chip, offset);
|
|
if (status == 0)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
|
|
trace_gpio_direction(desc_to_gpio(desc), 1, status);
|
|
lose:
|
|
return status;
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_input);
|
|
|
|
static int _gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
/* GPIOs used for IRQs shall not be set as output */
|
|
if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) {
|
|
gpiod_err(desc,
|
|
"%s: tried to set a GPIO tied to an IRQ as output\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
/* Open drain pin should not be driven to 1 */
|
|
if (value && test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
return gpiod_direction_input(desc);
|
|
|
|
/* Open source pin should not be driven to 0 */
|
|
if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
return gpiod_direction_input(desc);
|
|
|
|
chip = desc->chip;
|
|
if (!chip->set || !chip->direction_output) {
|
|
gpiod_warn(desc,
|
|
"%s: missing set() or direction_output() operations\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
if (status < 0)
|
|
goto fail;
|
|
|
|
/* now we know the gpio is valid and chip won't vanish */
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
might_sleep_if(chip->can_sleep);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
if (status) {
|
|
status = chip->request(chip, offset);
|
|
if (status < 0) {
|
|
gpiod_dbg(desc, "%s: chip request fail, %d\n",
|
|
__func__, status);
|
|
/* and it's not available to anyone else ...
|
|
* gpio_request() is the fully clean solution.
|
|
*/
|
|
goto lose;
|
|
}
|
|
}
|
|
|
|
status = chip->direction_output(chip, offset, value);
|
|
if (status == 0)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
trace_gpio_direction(desc_to_gpio(desc), 0, status);
|
|
lose:
|
|
return status;
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: gpio status %d\n", __func__, status);
|
|
return status;
|
|
}
|
|
|
|
/**
|
|
* gpiod_direction_output_raw - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as raw value on the physical line without regard for the ACTIVE_LOW status.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output_raw(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output_raw);
|
|
|
|
/**
|
|
* gpiod_direction_output - set the GPIO direction to output
|
|
* @desc: GPIO to set to output
|
|
* @value: initial output value of the GPIO
|
|
*
|
|
* Set the direction of the passed GPIO to output, such as gpiod_set_value() can
|
|
* be called safely on it. The initial value of the output must be specified
|
|
* as the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* Return 0 in case of success, else an error code.
|
|
*/
|
|
int gpiod_direction_output(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
return _gpiod_direction_output_raw(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_direction_output);
|
|
|
|
/**
|
|
* gpiod_set_debounce - sets @debounce time for a @gpio
|
|
* @gpio: the gpio to set debounce time
|
|
* @debounce: debounce time is microseconds
|
|
*
|
|
* returns -ENOTSUPP if the controller does not support setting
|
|
* debounce.
|
|
*/
|
|
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip;
|
|
int status = -EINVAL;
|
|
int offset;
|
|
|
|
if (!desc || !desc->chip) {
|
|
pr_warn("%s: invalid GPIO\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
chip = desc->chip;
|
|
if (!chip->set || !chip->set_debounce) {
|
|
gpiod_dbg(desc,
|
|
"%s: missing set() or set_debounce() operations\n",
|
|
__func__);
|
|
return -ENOTSUPP;
|
|
}
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
|
|
status = gpio_ensure_requested(desc);
|
|
if (status < 0)
|
|
goto fail;
|
|
|
|
/* now we know the gpio is valid and chip won't vanish */
|
|
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
might_sleep_if(chip->can_sleep);
|
|
|
|
offset = gpio_chip_hwgpio(desc);
|
|
return chip->set_debounce(chip, offset, debounce);
|
|
|
|
fail:
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
if (status)
|
|
gpiod_dbg(desc, "%s: status %d\n", __func__, status);
|
|
|
|
return status;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_debounce);
|
|
|
|
/**
|
|
* gpiod_is_active_low - test whether a GPIO is active-low or not
|
|
* @desc: the gpio descriptor to test
|
|
*
|
|
* Returns 1 if the GPIO is active-low, 0 otherwise.
|
|
*/
|
|
int gpiod_is_active_low(const struct gpio_desc *desc)
|
|
{
|
|
return test_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_is_active_low);
|
|
|
|
/* I/O calls are only valid after configuration completed; the relevant
|
|
* "is this a valid GPIO" error checks should already have been done.
|
|
*
|
|
* "Get" operations are often inlinable as reading a pin value register,
|
|
* and masking the relevant bit in that register.
|
|
*
|
|
* When "set" operations are inlinable, they involve writing that mask to
|
|
* one register to set a low value, or a different register to set it high.
|
|
* Otherwise locking is needed, so there may be little value to inlining.
|
|
*
|
|
*------------------------------------------------------------------------
|
|
*
|
|
* IMPORTANT!!! The hot paths -- get/set value -- assume that callers
|
|
* have requested the GPIO. That can include implicit requesting by
|
|
* a direction setting call. Marking a gpio as requested locks its chip
|
|
* in memory, guaranteeing that these table lookups need no more locking
|
|
* and that gpiochip_remove() will fail.
|
|
*
|
|
* REVISIT when debugging, consider adding some instrumentation to ensure
|
|
* that the GPIO was actually requested.
|
|
*/
|
|
|
|
static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
bool value;
|
|
int offset;
|
|
|
|
chip = desc->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
value = chip->get ? chip->get(chip, offset) : false;
|
|
trace_gpio_value(desc_to_gpio(desc), 1, value);
|
|
return value;
|
|
}
|
|
|
|
/**
|
|
* gpiod_get_raw_value() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_raw_value(const struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return 0;
|
|
/* Should be using gpio_get_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value);
|
|
|
|
/**
|
|
* gpiod_get_value() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
int gpiod_get_value(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
if (!desc)
|
|
return 0;
|
|
/* Should be using gpio_get_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value);
|
|
|
|
/*
|
|
* _gpio_set_open_drain_value() - Set the open drain gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_drain_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_output(chip, offset, 0);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open drain err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
/*
|
|
* _gpio_set_open_source_value() - Set the open source gpio's value.
|
|
* @desc: gpio descriptor whose state need to be set.
|
|
* @value: Non-zero for setting it HIGH otherise it will set to LOW.
|
|
*/
|
|
static void _gpio_set_open_source_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
int err = 0;
|
|
struct gpio_chip *chip = desc->chip;
|
|
int offset = gpio_chip_hwgpio(desc);
|
|
|
|
if (value) {
|
|
err = chip->direction_output(chip, offset, 1);
|
|
if (!err)
|
|
set_bit(FLAG_IS_OUT, &desc->flags);
|
|
} else {
|
|
err = chip->direction_input(chip, offset);
|
|
if (!err)
|
|
clear_bit(FLAG_IS_OUT, &desc->flags);
|
|
}
|
|
trace_gpio_direction(desc_to_gpio(desc), !value, err);
|
|
if (err < 0)
|
|
gpiod_err(desc,
|
|
"%s: Error in set_value for open source err %d\n",
|
|
__func__, err);
|
|
}
|
|
|
|
static void _gpiod_set_raw_value(struct gpio_desc *desc, bool value)
|
|
{
|
|
struct gpio_chip *chip;
|
|
|
|
chip = desc->chip;
|
|
trace_gpio_value(desc_to_gpio(desc), 0, value);
|
|
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
|
|
_gpio_set_open_drain_value(desc, value);
|
|
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
|
|
_gpio_set_open_source_value(desc, value);
|
|
else
|
|
chip->set(chip, gpio_chip_hwgpio(desc), value);
|
|
}
|
|
|
|
/**
|
|
* gpiod_set_raw_value() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_raw_value(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
/* Should be using gpio_set_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value);
|
|
|
|
/**
|
|
* gpiod_set_value() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function should be called from contexts where we cannot sleep, and will
|
|
* complain if the GPIO chip functions potentially sleep.
|
|
*/
|
|
void gpiod_set_value(struct gpio_desc *desc, int value)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
/* Should be using gpio_set_value_cansleep() */
|
|
WARN_ON(desc->chip->can_sleep);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value);
|
|
|
|
/**
|
|
* gpiod_cansleep() - report whether gpio value access may sleep
|
|
* @desc: gpio to check
|
|
*
|
|
*/
|
|
int gpiod_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return 0;
|
|
return desc->chip->can_sleep;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_cansleep);
|
|
|
|
/**
|
|
* gpiod_to_irq() - return the IRQ corresponding to a GPIO
|
|
* @desc: gpio whose IRQ will be returned (already requested)
|
|
*
|
|
* Return the IRQ corresponding to the passed GPIO, or an error code in case of
|
|
* error.
|
|
*/
|
|
int gpiod_to_irq(const struct gpio_desc *desc)
|
|
{
|
|
struct gpio_chip *chip;
|
|
int offset;
|
|
|
|
if (!desc)
|
|
return -EINVAL;
|
|
chip = desc->chip;
|
|
offset = gpio_chip_hwgpio(desc);
|
|
return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_to_irq);
|
|
|
|
/**
|
|
* gpiod_lock_as_irq() - lock a GPIO to be used as IRQ
|
|
* @gpio: the GPIO line to lock as used for IRQ
|
|
*
|
|
* This is used directly by GPIO drivers that want to lock down
|
|
* a certain GPIO line to be used for IRQs.
|
|
*/
|
|
int gpiod_lock_as_irq(struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return -EINVAL;
|
|
|
|
if (test_bit(FLAG_IS_OUT, &desc->flags)) {
|
|
gpiod_err(desc,
|
|
"%s: tried to flag a GPIO set as output for IRQ\n",
|
|
__func__);
|
|
return -EIO;
|
|
}
|
|
|
|
set_bit(FLAG_USED_AS_IRQ, &desc->flags);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_lock_as_irq);
|
|
|
|
int gpio_lock_as_irq(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
return gpiod_lock_as_irq(gpiochip_get_desc(chip, offset));
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_lock_as_irq);
|
|
|
|
/**
|
|
* gpiod_unlock_as_irq() - unlock a GPIO used as IRQ
|
|
* @gpio: the GPIO line to unlock from IRQ usage
|
|
*
|
|
* This is used directly by GPIO drivers that want to indicate
|
|
* that a certain GPIO is no longer used exclusively for IRQ.
|
|
*/
|
|
void gpiod_unlock_as_irq(struct gpio_desc *desc)
|
|
{
|
|
if (!desc)
|
|
return;
|
|
|
|
clear_bit(FLAG_USED_AS_IRQ, &desc->flags);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_unlock_as_irq);
|
|
|
|
void gpio_unlock_as_irq(struct gpio_chip *chip, unsigned int offset)
|
|
{
|
|
return gpiod_unlock_as_irq(gpiochip_get_desc(chip, offset));
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpio_unlock_as_irq);
|
|
|
|
/**
|
|
* gpiod_get_raw_value_cansleep() - return a gpio's raw value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's raw value, i.e. the value of the physical line disregarding
|
|
* its ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_raw_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return 0;
|
|
return _gpiod_get_raw_value(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_get_value_cansleep() - return a gpio's value
|
|
* @desc: gpio whose value will be returned
|
|
*
|
|
* Return the GPIO's logical value, i.e. taking the ACTIVE_LOW status into
|
|
* account.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
int gpiod_get_value_cansleep(const struct gpio_desc *desc)
|
|
{
|
|
int value;
|
|
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return 0;
|
|
|
|
value = _gpiod_get_raw_value(desc);
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
|
|
return value;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_raw_value_cansleep() - assign a gpio's raw value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the raw value of the GPIO, i.e. the value of its physical line without
|
|
* regard for its ACTIVE_LOW status.
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_raw_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_raw_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_set_value_cansleep() - assign a gpio's value
|
|
* @desc: gpio whose value will be assigned
|
|
* @value: value to assign
|
|
*
|
|
* Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into
|
|
* account
|
|
*
|
|
* This function is to be called from contexts that can sleep.
|
|
*/
|
|
void gpiod_set_value_cansleep(struct gpio_desc *desc, int value)
|
|
{
|
|
might_sleep_if(extra_checks);
|
|
if (!desc)
|
|
return;
|
|
|
|
if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
|
|
value = !value;
|
|
_gpiod_set_raw_value(desc, value);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_set_value_cansleep);
|
|
|
|
/**
|
|
* gpiod_add_lookup_table() - register GPIO device consumers
|
|
* @table: table of consumers to register
|
|
*/
|
|
void gpiod_add_lookup_table(struct gpiod_lookup_table *table)
|
|
{
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_add_tail(&table->list, &gpio_lookup_list);
|
|
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
char prop_name[32]; /* 32 is max size of property name */
|
|
enum of_gpio_flags of_flags;
|
|
struct gpio_desc *desc;
|
|
|
|
if (con_id)
|
|
snprintf(prop_name, 32, "%s-gpios", con_id);
|
|
else
|
|
snprintf(prop_name, 32, "gpios");
|
|
|
|
desc = of_get_named_gpiod_flags(dev->of_node, prop_name, idx,
|
|
&of_flags);
|
|
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
if (of_flags & OF_GPIO_ACTIVE_LOW)
|
|
*flags |= GPIO_ACTIVE_LOW;
|
|
|
|
return desc;
|
|
}
|
|
#else
|
|
static struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
#endif
|
|
|
|
static struct gpio_desc *acpi_find_gpio(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
struct acpi_gpio_info info;
|
|
struct gpio_desc *desc;
|
|
|
|
desc = acpi_get_gpiod_by_index(dev, idx, &info);
|
|
if (IS_ERR(desc))
|
|
return desc;
|
|
|
|
if (info.gpioint && info.active_low)
|
|
*flags |= GPIO_ACTIVE_LOW;
|
|
|
|
return desc;
|
|
}
|
|
|
|
static struct gpiod_lookup_table *gpiod_find_lookup_table(struct device *dev)
|
|
{
|
|
const char *dev_id = dev ? dev_name(dev) : NULL;
|
|
struct gpiod_lookup_table *table;
|
|
|
|
mutex_lock(&gpio_lookup_lock);
|
|
|
|
list_for_each_entry(table, &gpio_lookup_list, list) {
|
|
if (table->dev_id && dev_id) {
|
|
/*
|
|
* Valid strings on both ends, must be identical to have
|
|
* a match
|
|
*/
|
|
if (!strcmp(table->dev_id, dev_id))
|
|
goto found;
|
|
} else {
|
|
/*
|
|
* One of the pointers is NULL, so both must be to have
|
|
* a match
|
|
*/
|
|
if (dev_id == table->dev_id)
|
|
goto found;
|
|
}
|
|
}
|
|
table = NULL;
|
|
|
|
found:
|
|
mutex_unlock(&gpio_lookup_lock);
|
|
return table;
|
|
}
|
|
|
|
static struct gpio_desc *gpiod_find(struct device *dev, const char *con_id,
|
|
unsigned int idx,
|
|
enum gpio_lookup_flags *flags)
|
|
{
|
|
struct gpio_desc *desc = ERR_PTR(-ENOENT);
|
|
struct gpiod_lookup_table *table;
|
|
struct gpiod_lookup *p;
|
|
|
|
table = gpiod_find_lookup_table(dev);
|
|
if (!table)
|
|
return desc;
|
|
|
|
for (p = &table->table[0]; p->chip_label; p++) {
|
|
struct gpio_chip *chip;
|
|
|
|
/* idx must always match exactly */
|
|
if (p->idx != idx)
|
|
continue;
|
|
|
|
/* If the lookup entry has a con_id, require exact match */
|
|
if (p->con_id && (!con_id || strcmp(p->con_id, con_id)))
|
|
continue;
|
|
|
|
chip = find_chip_by_name(p->chip_label);
|
|
|
|
if (!chip) {
|
|
dev_err(dev, "cannot find GPIO chip %s\n",
|
|
p->chip_label);
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
if (chip->ngpio <= p->chip_hwnum) {
|
|
dev_err(dev,
|
|
"requested GPIO %d is out of range [0..%d] for chip %s\n",
|
|
idx, chip->ngpio, chip->label);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
desc = gpiochip_get_desc(chip, p->chip_hwnum);
|
|
*flags = p->flags;
|
|
|
|
return desc;
|
|
}
|
|
|
|
return desc;
|
|
}
|
|
|
|
/**
|
|
* gpio_get - obtain a GPIO for a given GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
*
|
|
* Return the GPIO descriptor corresponding to the function con_id of device
|
|
* dev, -ENOENT if no GPIO has been assigned to the requested function, or
|
|
* another IS_ERR() code if an error occured while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get(struct device *dev, const char *con_id)
|
|
{
|
|
return gpiod_get_index(dev, con_id, 0);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get);
|
|
|
|
/**
|
|
* gpiod_get_index - obtain a GPIO from a multi-index GPIO function
|
|
* @dev: GPIO consumer, can be NULL for system-global GPIOs
|
|
* @con_id: function within the GPIO consumer
|
|
* @idx: index of the GPIO to obtain in the consumer
|
|
*
|
|
* This variant of gpiod_get() allows to access GPIOs other than the first
|
|
* defined one for functions that define several GPIOs.
|
|
*
|
|
* Return a valid GPIO descriptor, -ENOENT if no GPIO has been assigned to the
|
|
* requested function and/or index, or another IS_ERR() code if an error
|
|
* occured while trying to acquire the GPIO.
|
|
*/
|
|
struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
|
|
const char *con_id,
|
|
unsigned int idx)
|
|
{
|
|
struct gpio_desc *desc = NULL;
|
|
int status;
|
|
enum gpio_lookup_flags flags = 0;
|
|
|
|
dev_dbg(dev, "GPIO lookup for consumer %s\n", con_id);
|
|
|
|
/* Using device tree? */
|
|
if (IS_ENABLED(CONFIG_OF) && dev && dev->of_node) {
|
|
dev_dbg(dev, "using device tree for GPIO lookup\n");
|
|
desc = of_find_gpio(dev, con_id, idx, &flags);
|
|
} else if (IS_ENABLED(CONFIG_ACPI) && dev && ACPI_HANDLE(dev)) {
|
|
dev_dbg(dev, "using ACPI for GPIO lookup\n");
|
|
desc = acpi_find_gpio(dev, con_id, idx, &flags);
|
|
}
|
|
|
|
/*
|
|
* Either we are not using DT or ACPI, or their lookup did not return
|
|
* a result. In that case, use platform lookup as a fallback.
|
|
*/
|
|
if (!desc || desc == ERR_PTR(-ENOENT)) {
|
|
dev_dbg(dev, "using lookup tables for GPIO lookup");
|
|
desc = gpiod_find(dev, con_id, idx, &flags);
|
|
}
|
|
|
|
if (IS_ERR(desc)) {
|
|
dev_dbg(dev, "lookup for GPIO %s failed\n", con_id);
|
|
return desc;
|
|
}
|
|
|
|
status = gpiod_request(desc, con_id);
|
|
|
|
if (status < 0)
|
|
return ERR_PTR(status);
|
|
|
|
if (flags & GPIO_ACTIVE_LOW)
|
|
set_bit(FLAG_ACTIVE_LOW, &desc->flags);
|
|
if (flags & GPIO_OPEN_DRAIN)
|
|
set_bit(FLAG_OPEN_DRAIN, &desc->flags);
|
|
if (flags & GPIO_OPEN_SOURCE)
|
|
set_bit(FLAG_OPEN_SOURCE, &desc->flags);
|
|
|
|
return desc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_get_index);
|
|
|
|
/**
|
|
* gpiod_put - dispose of a GPIO descriptor
|
|
* @desc: GPIO descriptor to dispose of
|
|
*
|
|
* No descriptor can be used after gpiod_put() has been called on it.
|
|
*/
|
|
void gpiod_put(struct gpio_desc *desc)
|
|
{
|
|
gpiod_free(desc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(gpiod_put);
|
|
|
|
#ifdef CONFIG_DEBUG_FS
|
|
|
|
static void gpiolib_dbg_show(struct seq_file *s, struct gpio_chip *chip)
|
|
{
|
|
unsigned i;
|
|
unsigned gpio = chip->base;
|
|
struct gpio_desc *gdesc = &chip->desc[0];
|
|
int is_out;
|
|
int is_irq;
|
|
|
|
for (i = 0; i < chip->ngpio; i++, gpio++, gdesc++) {
|
|
if (!test_bit(FLAG_REQUESTED, &gdesc->flags))
|
|
continue;
|
|
|
|
gpiod_get_direction(gdesc);
|
|
is_out = test_bit(FLAG_IS_OUT, &gdesc->flags);
|
|
is_irq = test_bit(FLAG_USED_AS_IRQ, &gdesc->flags);
|
|
seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s",
|
|
gpio, gdesc->label,
|
|
is_out ? "out" : "in ",
|
|
chip->get
|
|
? (chip->get(chip, i) ? "hi" : "lo")
|
|
: "? ",
|
|
is_irq ? "IRQ" : " ");
|
|
seq_printf(s, "\n");
|
|
}
|
|
}
|
|
|
|
static void *gpiolib_seq_start(struct seq_file *s, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip = NULL;
|
|
loff_t index = *pos;
|
|
|
|
s->private = "";
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
list_for_each_entry(chip, &gpio_chips, list)
|
|
if (index-- == 0) {
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
return chip;
|
|
}
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static void *gpiolib_seq_next(struct seq_file *s, void *v, loff_t *pos)
|
|
{
|
|
unsigned long flags;
|
|
struct gpio_chip *chip = v;
|
|
void *ret = NULL;
|
|
|
|
spin_lock_irqsave(&gpio_lock, flags);
|
|
if (list_is_last(&chip->list, &gpio_chips))
|
|
ret = NULL;
|
|
else
|
|
ret = list_entry(chip->list.next, struct gpio_chip, list);
|
|
spin_unlock_irqrestore(&gpio_lock, flags);
|
|
|
|
s->private = "\n";
|
|
++*pos;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void gpiolib_seq_stop(struct seq_file *s, void *v)
|
|
{
|
|
}
|
|
|
|
static int gpiolib_seq_show(struct seq_file *s, void *v)
|
|
{
|
|
struct gpio_chip *chip = v;
|
|
struct device *dev;
|
|
|
|
seq_printf(s, "%sGPIOs %d-%d", (char *)s->private,
|
|
chip->base, chip->base + chip->ngpio - 1);
|
|
dev = chip->dev;
|
|
if (dev)
|
|
seq_printf(s, ", %s/%s", dev->bus ? dev->bus->name : "no-bus",
|
|
dev_name(dev));
|
|
if (chip->label)
|
|
seq_printf(s, ", %s", chip->label);
|
|
if (chip->can_sleep)
|
|
seq_printf(s, ", can sleep");
|
|
seq_printf(s, ":\n");
|
|
|
|
if (chip->dbg_show)
|
|
chip->dbg_show(s, chip);
|
|
else
|
|
gpiolib_dbg_show(s, chip);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations gpiolib_seq_ops = {
|
|
.start = gpiolib_seq_start,
|
|
.next = gpiolib_seq_next,
|
|
.stop = gpiolib_seq_stop,
|
|
.show = gpiolib_seq_show,
|
|
};
|
|
|
|
static int gpiolib_open(struct inode *inode, struct file *file)
|
|
{
|
|
return seq_open(file, &gpiolib_seq_ops);
|
|
}
|
|
|
|
static const struct file_operations gpiolib_operations = {
|
|
.owner = THIS_MODULE,
|
|
.open = gpiolib_open,
|
|
.read = seq_read,
|
|
.llseek = seq_lseek,
|
|
.release = seq_release,
|
|
};
|
|
|
|
static int __init gpiolib_debugfs_init(void)
|
|
{
|
|
/* /sys/kernel/debug/gpio */
|
|
(void) debugfs_create_file("gpio", S_IFREG | S_IRUGO,
|
|
NULL, NULL, &gpiolib_operations);
|
|
return 0;
|
|
}
|
|
subsys_initcall(gpiolib_debugfs_init);
|
|
|
|
#endif /* DEBUG_FS */
|