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gpio: Add a driver for Cortina Systems Gemini GPIO 

This is a heavy edit/rewrite of the GPIO driver for the Gemini
SoC from arch/arm/mach-gemini/gpio.c.

This rewrite uses all the best-in-class helper like generic
GPIO and GPIOLIB_IRQCHIP and has been tested on ITian Square One
Gemini-based NAS/router.

Cc: Janos Laube <janos.dev@gmail.com>
Cc: Paulius Zaleckas <paulius.zaleckas@gmail.com>
Cc: Hans Ulli Kroll <ulli.kroll@googlemail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This commit is contained in:
Linus Walleij 2017-01-22 13:18:44 +01:00
parent 284864f990
commit 49cec4d832
3 changed files with 246 additions and 0 deletions
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9
drivers/gpio/Kconfig
View File

@ -197,6 +197,15 @@ config GPIO_GE_FPGA
and write pin state) for GPIO implemented in a number of GE single
board computers.
config GPIO_GEMINI
bool "Gemini GPIO"
depends on ARCH_GEMINI
depends on OF_GPIO
select GPIO_GENERIC
select GPIOLIB_IRQCHIP
help
Support for common GPIOs found in Cortina systems Gemini platforms.
config GPIO_GENERIC_PLATFORM
tristate "Generic memory-mapped GPIO controller support (MMIO platform device)"
select GPIO_GENERIC

1
drivers/gpio/Makefile
View File

@ -48,6 +48,7 @@ obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_ETRAXFS) += gpio-etraxfs.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
obj-$(CONFIG_GPIO_GEMINI) += gpio-gemini.o
obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o
obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o
obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o

236
drivers/gpio/gpio-gemini.c Normal file
View File

@ -0,0 +1,236 @@
/*
* Gemini gpiochip and interrupt routines
* Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
*
* Based on arch/arm/mach-gemini/gpio.c:
* Copyright (C) 2008-2009 Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
*
* Based on plat-mxc/gpio.c:
* MXC GPIO support. (c) 2008 Daniel Mack <daniel@caiaq.de>
* Copyright 2008 Juergen Beisert, kernel@pengutronix.de
*/
#include <linux/gpio/driver.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of_gpio.h>
#include <linux/bitops.h>
/* GPIO registers definition */
#define GPIO_DATA_OUT 0x00
#define GPIO_DATA_IN 0x04
#define GPIO_DIR 0x08
#define GPIO_DATA_SET 0x10
#define GPIO_DATA_CLR 0x14
#define GPIO_PULL_EN 0x18
#define GPIO_PULL_TYPE 0x1C
#define GPIO_INT_EN 0x20
#define GPIO_INT_STAT 0x24
#define GPIO_INT_MASK 0x2C
#define GPIO_INT_CLR 0x30
#define GPIO_INT_TYPE 0x34
#define GPIO_INT_BOTH_EDGE 0x38
#define GPIO_INT_LEVEL 0x3C
#define GPIO_DEBOUNCE_EN 0x40
#define GPIO_DEBOUNCE_PRESCALE 0x44
/**
* struct gemini_gpio - Gemini GPIO state container
* @dev: containing device for this instance
* @gc: gpiochip for this instance
*/
struct gemini_gpio {
struct device *dev;
struct gpio_chip gc;
void __iomem *base;
};
static void gemini_gpio_ack_irq(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct gemini_gpio *g = gpiochip_get_data(gc);
writel(BIT(irqd_to_hwirq(d)), g->base + GPIO_INT_CLR);
}
static void gemini_gpio_mask_irq(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct gemini_gpio *g = gpiochip_get_data(gc);
u32 val;
val = readl(g->base + GPIO_INT_EN);
val &= ~BIT(irqd_to_hwirq(d));
writel(val, g->base + GPIO_INT_EN);
}
static void gemini_gpio_unmask_irq(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct gemini_gpio *g = gpiochip_get_data(gc);
u32 val;
val = readl(g->base + GPIO_INT_EN);
val |= BIT(irqd_to_hwirq(d));
writel(val, g->base + GPIO_INT_EN);
}
static int gemini_gpio_set_irq_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct gemini_gpio *g = gpiochip_get_data(gc);
u32 mask = BIT(irqd_to_hwirq(d));
u32 reg_both, reg_level, reg_type;
reg_type = readl(g->base + GPIO_INT_TYPE);
reg_level = readl(g->base + GPIO_INT_LEVEL);
reg_both = readl(g->base + GPIO_INT_BOTH_EDGE);
switch (type) {
case IRQ_TYPE_EDGE_BOTH:
irq_set_handler_locked(d, handle_edge_irq);
reg_type &= ~mask;
reg_both |= mask;
break;
case IRQ_TYPE_EDGE_RISING:
irq_set_handler_locked(d, handle_edge_irq);
reg_type &= ~mask;
reg_both &= ~mask;
reg_level &= ~mask;
break;
case IRQ_TYPE_EDGE_FALLING:
irq_set_handler_locked(d, handle_edge_irq);
reg_type &= ~mask;
reg_both &= ~mask;
reg_level |= mask;
break;
case IRQ_TYPE_LEVEL_HIGH:
irq_set_handler_locked(d, handle_level_irq);
reg_type |= mask;
reg_level &= ~mask;
break;
case IRQ_TYPE_LEVEL_LOW:
irq_set_handler_locked(d, handle_level_irq);
reg_type |= mask;
reg_level |= mask;
break;
default:
irq_set_handler_locked(d, handle_bad_irq);
return -EINVAL;
}
writel(reg_type, g->base + GPIO_INT_TYPE);
writel(reg_level, g->base + GPIO_INT_LEVEL);
writel(reg_both, g->base + GPIO_INT_BOTH_EDGE);
gemini_gpio_ack_irq(d);
return 0;
}
static struct irq_chip gemini_gpio_irqchip = {
.name = "GPIO",
.irq_ack = gemini_gpio_ack_irq,
.irq_mask = gemini_gpio_mask_irq,
.irq_unmask = gemini_gpio_unmask_irq,
.irq_set_type = gemini_gpio_set_irq_type,
};
static void gemini_gpio_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct gemini_gpio *g = gpiochip_get_data(gc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
int offset;
unsigned long stat;
chained_irq_enter(irqchip, desc);
stat = readl(g->base + GPIO_INT_STAT);
if (stat)
for_each_set_bit(offset, &stat, gc->ngpio)
generic_handle_irq(irq_find_mapping(gc->irqdomain,
offset));
chained_irq_exit(irqchip, desc);
}
static int gemini_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct gemini_gpio *g;
int irq;
int ret;
g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
if (!g)
return -ENOMEM;
g->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
g->base = devm_ioremap_resource(dev, res);
if (IS_ERR(g->base))
return PTR_ERR(g->base);
irq = platform_get_irq(pdev, 0);
if (!irq)
return -EINVAL;
ret = bgpio_init(&g->gc, dev, 4,
g->base + GPIO_DATA_IN,
g->base + GPIO_DATA_SET,
g->base + GPIO_DATA_CLR,
g->base + GPIO_DIR,
NULL,
0);
if (ret) {
dev_err(dev, "unable to init generic GPIO\n");
return ret;
}
g->gc.label = "Gemini";
g->gc.base = -1;
g->gc.parent = dev;
g->gc.owner = THIS_MODULE;
/* ngpio is set by bgpio_init() */
ret = devm_gpiochip_add_data(dev, &g->gc, g);
if (ret)
return ret;
/* Disable, unmask and clear all interrupts */
writel(0x0, g->base + GPIO_INT_EN);
writel(0x0, g->base + GPIO_INT_MASK);
writel(~0x0, g->base + GPIO_INT_CLR);
ret = gpiochip_irqchip_add(&g->gc, &gemini_gpio_irqchip,
0, handle_bad_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_info(dev, "could not add irqchip\n");
return ret;
}
gpiochip_set_chained_irqchip(&g->gc, &gemini_gpio_irqchip,
irq, gemini_gpio_irq_handler);
dev_info(dev, "Gemini GPIO @%p registered\n", g->base);
return 0;
}
static const struct of_device_id gemini_gpio_of_match[] = {
{
.compatible = "cortina,gemini-gpio",
},
{},
};
static struct platform_driver gemini_gpio_driver = {
.driver = {
.name = "gemini-gpio",
.of_match_table = of_match_ptr(gemini_gpio_of_match),
},
.probe = gemini_gpio_probe,
};
builtin_platform_driver(gemini_gpio_driver);