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/*
* AppliedMicro X-Gene SoC GPIO Driver
*
* Copyright (c) 2014, Applied Micro Circuits Corporation
* Author: Feng Kan <fkan@apm.com>.
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/gpio/driver.h>
#include <linux/types.h>
#include <linux/bitops.h>
#define GPIO_SET_DR_OFFSET 0x0C
#define GPIO_DATA_OFFSET 0x14
#define GPIO_BANK_STRIDE 0x0C
#define XGENE_GPIOS_PER_BANK 16
#define XGENE_MAX_GPIO_BANKS 3
#define XGENE_MAX_GPIOS (XGENE_GPIOS_PER_BANK * XGENE_MAX_GPIO_BANKS)
#define GPIO_BIT_OFFSET(x) (x % XGENE_GPIOS_PER_BANK)
#define GPIO_BANK_OFFSET(x) ((x / XGENE_GPIOS_PER_BANK) * GPIO_BANK_STRIDE)
struct xgene_gpio {
struct gpio_chip chip;
void __iomem *base;
spinlock_t lock;
#ifdef CONFIG_PM
u32 set_dr_val[XGENE_MAX_GPIO_BANKS];
#endif
};
static inline struct xgene_gpio *to_xgene_gpio(struct gpio_chip *chip)
{
return container_of(chip, struct xgene_gpio, chip);
}
static int xgene_gpio_get(struct gpio_chip *gc, unsigned int offset)
{
struct xgene_gpio *chip = to_xgene_gpio(gc);
unsigned long bank_offset;
u32 bit_offset;
bank_offset = GPIO_DATA_OFFSET + GPIO_BANK_OFFSET(offset);
bit_offset = GPIO_BIT_OFFSET(offset);
return !!(ioread32(chip->base + bank_offset) & BIT(bit_offset));
}
static void __xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
struct xgene_gpio *chip = to_xgene_gpio(gc);
unsigned long bank_offset;
u32 setval, bit_offset;
bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
bit_offset = GPIO_BIT_OFFSET(offset) + XGENE_GPIOS_PER_BANK;
setval = ioread32(chip->base + bank_offset);
if (val)
setval |= BIT(bit_offset);
else
setval &= ~BIT(bit_offset);
iowrite32(setval, chip->base + bank_offset);
}
static void xgene_gpio_set(struct gpio_chip *gc, unsigned int offset, int val)
{
struct xgene_gpio *chip = to_xgene_gpio(gc);
unsigned long flags;
spin_lock_irqsave(&chip->lock, flags);
__xgene_gpio_set(gc, offset, val);
spin_unlock_irqrestore(&chip->lock, flags);
}
static int xgene_gpio_dir_in(struct gpio_chip *gc, unsigned int offset)
{
struct xgene_gpio *chip = to_xgene_gpio(gc);
unsigned long flags, bank_offset;
u32 dirval, bit_offset;
bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
bit_offset = GPIO_BIT_OFFSET(offset);
spin_lock_irqsave(&chip->lock, flags);
dirval = ioread32(chip->base + bank_offset);
dirval |= BIT(bit_offset);
iowrite32(dirval, chip->base + bank_offset);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int xgene_gpio_dir_out(struct gpio_chip *gc,
unsigned int offset, int val)
{
struct xgene_gpio *chip = to_xgene_gpio(gc);
unsigned long flags, bank_offset;
u32 dirval, bit_offset;
bank_offset = GPIO_SET_DR_OFFSET + GPIO_BANK_OFFSET(offset);
bit_offset = GPIO_BIT_OFFSET(offset);
spin_lock_irqsave(&chip->lock, flags);
dirval = ioread32(chip->base + bank_offset);
dirval &= ~BIT(bit_offset);
iowrite32(dirval, chip->base + bank_offset);
__xgene_gpio_set(gc, offset, val);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
#ifdef CONFIG_PM
static int xgene_gpio_suspend(struct device *dev)
{
struct xgene_gpio *gpio = dev_get_drvdata(dev);
unsigned long bank_offset;
unsigned int bank;
for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
gpio->set_dr_val[bank] = ioread32(gpio->base + bank_offset);
}
return 0;
}
static int xgene_gpio_resume(struct device *dev)
{
struct xgene_gpio *gpio = dev_get_drvdata(dev);
unsigned long bank_offset;
unsigned int bank;
for (bank = 0; bank < XGENE_MAX_GPIO_BANKS; bank++) {
bank_offset = GPIO_SET_DR_OFFSET + bank * GPIO_BANK_STRIDE;
iowrite32(gpio->set_dr_val[bank], gpio->base + bank_offset);
}
return 0;
}
static SIMPLE_DEV_PM_OPS(xgene_gpio_pm, xgene_gpio_suspend, xgene_gpio_resume);
#define XGENE_GPIO_PM_OPS (&xgene_gpio_pm)
#else
#define XGENE_GPIO_PM_OPS NULL
#endif
static int xgene_gpio_probe(struct platform_device *pdev)
{
struct resource *res;
struct xgene_gpio *gpio;
int err = 0;
gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL);
if (!gpio) {
err = -ENOMEM;
goto err;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
gpio->base = devm_ioremap_nocache(&pdev->dev, res->start,
resource_size(res));
if (!gpio->base) {
err = -ENOMEM;
goto err;
}
gpio->chip.ngpio = XGENE_MAX_GPIOS;
spin_lock_init(&gpio->lock);
gpio->chip.dev = &pdev->dev;
gpio->chip.direction_input = xgene_gpio_dir_in;
gpio->chip.direction_output = xgene_gpio_dir_out;
gpio->chip.get = xgene_gpio_get;
gpio->chip.set = xgene_gpio_set;
gpio->chip.label = dev_name(&pdev->dev);
gpio->chip.base = -1;
platform_set_drvdata(pdev, gpio);
err = gpiochip_add(&gpio->chip);
if (err) {
dev_err(&pdev->dev,
"failed to register gpiochip.\n");
goto err;
}
dev_info(&pdev->dev, "X-Gene GPIO driver registered.\n");
return 0;
err:
dev_err(&pdev->dev, "X-Gene GPIO driver registration failed.\n");
return err;
}
static int xgene_gpio_remove(struct platform_device *pdev)
{
struct xgene_gpio *gpio = platform_get_drvdata(pdev);
gpiochip_remove(&gpio->chip);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id xgene_gpio_of_match[] = {
{ .compatible = "apm,xgene-gpio", },
{},
};
MODULE_DEVICE_TABLE(of, xgene_gpio_of_match);
#endif
static struct platform_driver xgene_gpio_driver = {
.driver = {
.name = "xgene-gpio",
.owner = THIS_MODULE,
.of_match_table = xgene_gpio_of_match,
.pm = XGENE_GPIO_PM_OPS,
},
.probe = xgene_gpio_probe,
.remove = xgene_gpio_remove,
};
module_platform_driver(xgene_gpio_driver);
MODULE_AUTHOR("Feng Kan <fkan@apm.com>");
MODULE_DESCRIPTION("APM X-Gene GPIO driver");
MODULE_LICENSE("GPL");
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