gpio-moxart.c
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/*
* MOXA ART SoCs GPIO driver.
*
* Copyright (C) 2013 Jonas Jensen
*
* Jonas Jensen <jonas.jensen@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/err.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/consumer.h>
#include <linux/delay.h>
#include <linux/timer.h>
#include <linux/bitops.h>
#define GPIO_DATA_OUT 0x00
#define GPIO_DATA_IN 0x04
#define GPIO_PIN_DIRECTION 0x08
struct moxart_gpio_chip {
struct gpio_chip gpio;
void __iomem *base;
};
static inline struct moxart_gpio_chip *to_moxart_gpio(struct gpio_chip *chip)
{
return container_of(chip, struct moxart_gpio_chip, gpio);
}
static int moxart_gpio_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_request_gpio(offset);
}
static void moxart_gpio_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_free_gpio(offset);
}
static int moxart_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
void __iomem *ioaddr = gc->base + GPIO_PIN_DIRECTION;
writel(readl(ioaddr) & ~BIT(offset), ioaddr);
return 0;
}
static int moxart_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
void __iomem *ioaddr = gc->base + GPIO_PIN_DIRECTION;
writel(readl(ioaddr) | BIT(offset), ioaddr);
return 0;
}
static void moxart_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
void __iomem *ioaddr = gc->base + GPIO_DATA_OUT;
u32 reg = readl(ioaddr);
if (value)
reg = reg | BIT(offset);
else
reg = reg & ~BIT(offset);
writel(reg, ioaddr);
}
static int moxart_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct moxart_gpio_chip *gc = to_moxart_gpio(chip);
u32 ret = readl(gc->base + GPIO_PIN_DIRECTION);
if (ret & BIT(offset))
return !!(readl(gc->base + GPIO_DATA_OUT) & BIT(offset));
else
return !!(readl(gc->base + GPIO_DATA_IN) & BIT(offset));
}
static struct gpio_chip moxart_template_chip = {
.label = "moxart-gpio",
.request = moxart_gpio_request,
.free = moxart_gpio_free,
.direction_input = moxart_gpio_direction_input,
.direction_output = moxart_gpio_direction_output,
.set = moxart_gpio_set,
.get = moxart_gpio_get,
.ngpio = 32,
.owner = THIS_MODULE,
};
static int moxart_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct resource *res;
struct moxart_gpio_chip *mgc;
int ret;
mgc = devm_kzalloc(dev, sizeof(*mgc), GFP_KERNEL);
if (!mgc) {
dev_err(dev, "can't allocate GPIO chip container\n");
return -ENOMEM;
}
mgc->gpio = moxart_template_chip;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mgc->base = devm_ioremap_resource(dev, res);
if (IS_ERR(mgc->base))
return PTR_ERR(mgc->base);
mgc->gpio.dev = dev;
ret = gpiochip_add(&mgc->gpio);
if (ret) {
dev_err(dev, "%s: gpiochip_add failed\n",
dev->of_node->full_name);
return ret;
}
return 0;
}
static const struct of_device_id moxart_gpio_match[] = {
{ .compatible = "moxa,moxart-gpio" },
{ }
};
static struct platform_driver moxart_gpio_driver = {
.driver = {
.name = "moxart-gpio",
.owner = THIS_MODULE,
.of_match_table = moxart_gpio_match,
},
.probe = moxart_gpio_probe,
};
module_platform_driver(moxart_gpio_driver);
MODULE_DESCRIPTION("MOXART GPIO chip driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");