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openwrt-xburst/target/linux/mcs814x/files-3.3/drivers/gpio/gpio-mcs814x.c
florian 08b17128a1 [mcs814x] use the recommended ARM I/O accessors
use {read,write}l_relaxed instead of the plain __raw_{read,write}l variants.

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@33330 3c298f89-4303-0410-b956-a3cf2f4a3e73
2012-09-08 09:51:05 +00:00

149 lines
3.5 KiB
C

/*
* Moschip MCS814x GPIO support
*
* Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
*
* Licensed under the GPLv2
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_address.h>
struct mcs814x_gpio_chip {
void __iomem *regs;
struct gpio_chip chip;
};
#define GPIO_PIN 0x00
#define GPIO_DIR 0x04
#define to_mcs814x_gpio_chip(x) container_of(x, struct mcs814x_gpio_chip, chip)
static int mcs814x_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
return readl_relaxed(mcs814x->regs + GPIO_PIN) & (1 << offset);
}
static void mcs814x_gpio_set(struct gpio_chip *chip,
unsigned offset, int value)
{
struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
u32 mask;
mask = readl_relaxed(mcs814x->regs + GPIO_PIN);
if (value)
mask |= (1 << offset);
else
mask &= ~(1 << offset);
writel_relaxed(mask, mcs814x->regs + GPIO_PIN);
}
static int mcs814x_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
u32 mask;
mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
mask &= ~(1 << offset);
writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
return 0;
}
static int mcs814x_gpio_direction_input(struct gpio_chip *chip,
unsigned offset)
{
struct mcs814x_gpio_chip *mcs814x = to_mcs814x_gpio_chip(chip);
u32 mask;
mask = readl_relaxed(mcs814x->regs + GPIO_DIR);
mask |= (1 << offset);
writel_relaxed(mask, mcs814x->regs + GPIO_DIR);
return 0;
}
static int __devinit mcs814x_gpio_probe(struct platform_device *pdev)
{
struct resource *res;
struct mcs814x_gpio_chip *mcs814x_chip;
int ret;
const unsigned int *num_gpios;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENODEV;
num_gpios = of_get_property(pdev->dev.of_node, "num-gpios", NULL);
if (!num_gpios)
dev_err(&pdev->dev, "FIXME: no num-gpios property\n");
mcs814x_chip = kzalloc(sizeof(*mcs814x_chip), GFP_KERNEL);
if (!mcs814x_chip)
return -ENOMEM;
mcs814x_chip->regs = devm_request_and_ioremap(&pdev->dev, res);
if (!mcs814x_chip->regs) {
ret = -ENOMEM;
goto out;
}
platform_set_drvdata(pdev, mcs814x_chip);
#ifdef CONFIG_OF_GPIO
mcs814x_chip->chip.of_node = pdev->dev.of_node;
#endif
mcs814x_chip->chip.label = pdev->name;
mcs814x_chip->chip.get = mcs814x_gpio_get;
mcs814x_chip->chip.set = mcs814x_gpio_set;
mcs814x_chip->chip.direction_input = mcs814x_gpio_direction_input;
mcs814x_chip->chip.direction_output = mcs814x_gpio_direction_output;
mcs814x_chip->chip.ngpio = be32_to_cpup(num_gpios);
/* we want dynamic base allocation */
mcs814x_chip->chip.base = -1;
ret = gpiochip_add(&mcs814x_chip->chip);
if (ret) {
dev_err(&pdev->dev, "failed to register gpiochip\n");
goto out;
}
return 0;
out:
platform_set_drvdata(pdev, NULL);
kfree(mcs814x_chip);
return ret;
}
static struct of_device_id mcs814x_gpio_ids[] __devinitdata = {
{ .compatible = "moschip,mcs814x-gpio" },
{ /* sentinel */ },
};
static struct platform_driver mcs814x_gpio_driver = {
.driver = {
.name = "mcs814x-gpio",
.owner = THIS_MODULE,
.of_match_table = mcs814x_gpio_ids,
},
.probe = mcs814x_gpio_probe,
};
int __init mcs814x_gpio_init(void)
{
return platform_driver_register(&mcs814x_gpio_driver);
}
postcore_initcall(mcs814x_gpio_init);