/* * ZTE ZX296702 GPIO driver * * Author: Jun Nie <jun.nie@linaro.org> * * Copyright (C) 2015 Linaro Ltd. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <linux/bitops.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/gpio/driver.h> #include <linux/irqchip/chained_irq.h> #include <linux/init.h> #include <linux/of.h> #include <linux/pinctrl/consumer.h> #include <linux/platform_device.h> #include <linux/pm.h> #include <linux/slab.h> #include <linux/spinlock.h> #define ZX_GPIO_DIR 0x00 #define ZX_GPIO_IVE 0x04 #define ZX_GPIO_IV 0x08 #define ZX_GPIO_IEP 0x0C #define ZX_GPIO_IEN 0x10 #define ZX_GPIO_DI 0x14 #define ZX_GPIO_DO1 0x18 #define ZX_GPIO_DO0 0x1C #define ZX_GPIO_DO 0x20 #define ZX_GPIO_IM 0x28 #define ZX_GPIO_IE 0x2C #define ZX_GPIO_MIS 0x30 #define ZX_GPIO_IC 0x34 #define ZX_GPIO_NR 16 struct zx_gpio { raw_spinlock_t lock; void __iomem *base; struct gpio_chip gc; }; static int zx_direction_input(struct gpio_chip *gc, unsigned offset) { struct zx_gpio *chip = gpiochip_get_data(gc); unsigned long flags; u16 gpiodir; if (offset >= gc->ngpio) return -EINVAL; raw_spin_lock_irqsave(&chip->lock, flags); gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); gpiodir &= ~BIT(offset); writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } static int zx_direction_output(struct gpio_chip *gc, unsigned offset, int value) { struct zx_gpio *chip = gpiochip_get_data(gc); unsigned long flags; u16 gpiodir; if (offset >= gc->ngpio) return -EINVAL; raw_spin_lock_irqsave(&chip->lock, flags); gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR); gpiodir |= BIT(offset); writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR); if (value) writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1); else writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0); raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } static int zx_get_value(struct gpio_chip *gc, unsigned offset) { struct zx_gpio *chip = gpiochip_get_data(gc); return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset)); } static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value) { struct zx_gpio *chip = gpiochip_get_data(gc); if (value) writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1); else writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0); } static int zx_irq_type(struct irq_data *d, unsigned trigger) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct zx_gpio *chip = gpiochip_get_data(gc); int offset = irqd_to_hwirq(d); unsigned long flags; u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev; u16 bit = BIT(offset); if (offset < 0 || offset >= ZX_GPIO_NR) return -EINVAL; raw_spin_lock_irqsave(&chip->lock, flags); gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV); gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE); gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP); gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN); if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { gpiois |= bit; if (trigger & IRQ_TYPE_LEVEL_HIGH) gpioiev |= bit; else gpioiev &= ~bit; } else gpiois &= ~bit; if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { gpioi_epos |= bit; gpioi_eneg |= bit; } else { if (trigger & IRQ_TYPE_EDGE_RISING) { gpioi_epos |= bit; gpioi_eneg &= ~bit; } else if (trigger & IRQ_TYPE_EDGE_FALLING) { gpioi_eneg |= bit; gpioi_epos &= ~bit; } } writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE); writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP); writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN); writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV); raw_spin_unlock_irqrestore(&chip->lock, flags); return 0; } static void zx_irq_handler(struct irq_desc *desc) { unsigned long pending; int offset; struct gpio_chip *gc = irq_desc_get_handler_data(desc); struct zx_gpio *chip = gpiochip_get_data(gc); struct irq_chip *irqchip = irq_desc_get_chip(desc); chained_irq_enter(irqchip, desc); pending = readw_relaxed(chip->base + ZX_GPIO_MIS); writew_relaxed(pending, chip->base + ZX_GPIO_IC); if (pending) { for_each_set_bit(offset, &pending, ZX_GPIO_NR) generic_handle_irq(irq_find_mapping(gc->irq.domain, offset)); } chained_irq_exit(irqchip, desc); } static void zx_irq_mask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct zx_gpio *chip = gpiochip_get_data(gc); u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); u16 gpioie; raw_spin_lock(&chip->lock); gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); raw_spin_unlock(&chip->lock); } static void zx_irq_unmask(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct zx_gpio *chip = gpiochip_get_data(gc); u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR); u16 gpioie; raw_spin_lock(&chip->lock); gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IM); gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask; writew_relaxed(gpioie, chip->base + ZX_GPIO_IE); raw_spin_unlock(&chip->lock); } static struct irq_chip zx_irqchip = { .name = "zx-gpio", .irq_mask = zx_irq_mask, .irq_unmask = zx_irq_unmask, .irq_set_type = zx_irq_type, }; static int zx_gpio_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct zx_gpio *chip; struct resource *res; int irq, id, ret; chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); chip->base = devm_ioremap_resource(dev, res); if (IS_ERR(chip->base)) return PTR_ERR(chip->base); raw_spin_lock_init(&chip->lock); if (of_property_read_bool(dev->of_node, "gpio-ranges")) { chip->gc.request = gpiochip_generic_request; chip->gc.free = gpiochip_generic_free; } id = of_alias_get_id(dev->of_node, "gpio"); chip->gc.direction_input = zx_direction_input; chip->gc.direction_output = zx_direction_output; chip->gc.get = zx_get_value; chip->gc.set = zx_set_value; chip->gc.base = ZX_GPIO_NR * id; chip->gc.ngpio = ZX_GPIO_NR; chip->gc.label = dev_name(dev); chip->gc.parent = dev; chip->gc.owner = THIS_MODULE; ret = gpiochip_add_data(&chip->gc, chip); if (ret) return ret; /* * irq_chip support */ writew_relaxed(0xffff, chip->base + ZX_GPIO_IM); writew_relaxed(0, chip->base + ZX_GPIO_IE); irq = platform_get_irq(pdev, 0); if (irq < 0) { dev_err(dev, "invalid IRQ\n"); gpiochip_remove(&chip->gc); return -ENODEV; } ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip, 0, handle_simple_irq, IRQ_TYPE_NONE); if (ret) { dev_err(dev, "could not add irqchip\n"); gpiochip_remove(&chip->gc); return ret; } gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip, irq, zx_irq_handler); platform_set_drvdata(pdev, chip); dev_info(dev, "ZX GPIO chip registered\n"); return 0; } static const struct of_device_id zx_gpio_match[] = { { .compatible = "zte,zx296702-gpio", }, { }, }; static struct platform_driver zx_gpio_driver = { .probe = zx_gpio_probe, .driver = { .name = "zx_gpio", .of_match_table = of_match_ptr(zx_gpio_match), }, }; builtin_platform_driver(zx_gpio_driver)