linux/arch/arm/plat-samsung/gpio.c

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/* linux/arch/arm/plat-s3c/gpio.c
*
* Copyright 2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* S3C series GPIO core
*
* 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/kernel.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/spinlock.h>
#include <plat/gpio-core.h>
#ifdef CONFIG_S3C_GPIO_TRACK
struct s3c_gpio_chip *s3c_gpios[S3C_GPIO_END];
static __init void s3c_gpiolib_track(struct s3c_gpio_chip *chip)
{
unsigned int gpn;
int i;
gpn = chip->chip.base;
for (i = 0; i < chip->chip.ngpio; i++, gpn++) {
BUG_ON(gpn >= ARRAY_SIZE(s3c_gpios));
s3c_gpios[gpn] = chip;
}
}
#endif /* CONFIG_S3C_GPIO_TRACK */
/* Default routines for controlling GPIO, based on the original S3C24XX
* GPIO functions which deal with the case where each gpio bank of the
* chip is as following:
*
* base + 0x00: Control register, 2 bits per gpio
* gpio n: 2 bits starting at (2*n)
* 00 = input, 01 = output, others mean special-function
* base + 0x04: Data register, 1 bit per gpio
* bit n: data bit n
*/
static int s3c_gpiolib_input(struct gpio_chip *chip, unsigned offset)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
unsigned long flags;
unsigned long con;
s3c_gpio_lock(ourchip, flags);
con = __raw_readl(base + 0x00);
con &= ~(3 << (offset * 2));
__raw_writel(con, base + 0x00);
s3c_gpio_unlock(ourchip, flags);
return 0;
}
static int s3c_gpiolib_output(struct gpio_chip *chip,
unsigned offset, int value)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
unsigned long flags;
unsigned long dat;
unsigned long con;
s3c_gpio_lock(ourchip, flags);
dat = __raw_readl(base + 0x04);
dat &= ~(1 << offset);
if (value)
dat |= 1 << offset;
__raw_writel(dat, base + 0x04);
con = __raw_readl(base + 0x00);
con &= ~(3 << (offset * 2));
con |= 1 << (offset * 2);
__raw_writel(con, base + 0x00);
__raw_writel(dat, base + 0x04);
s3c_gpio_unlock(ourchip, flags);
return 0;
}
static void s3c_gpiolib_set(struct gpio_chip *chip,
unsigned offset, int value)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
unsigned long flags;
unsigned long dat;
s3c_gpio_lock(ourchip, flags);
dat = __raw_readl(base + 0x04);
dat &= ~(1 << offset);
if (value)
dat |= 1 << offset;
__raw_writel(dat, base + 0x04);
s3c_gpio_unlock(ourchip, flags);
}
static int s3c_gpiolib_get(struct gpio_chip *chip, unsigned offset)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
unsigned long val;
val = __raw_readl(ourchip->base + 0x04);
val >>= offset;
val &= 1;
return val;
}
__init void s3c_gpiolib_add(struct s3c_gpio_chip *chip)
{
struct gpio_chip *gc = &chip->chip;
int ret;
BUG_ON(!chip->base);
BUG_ON(!gc->label);
BUG_ON(!gc->ngpio);
spin_lock_init(&chip->lock);
if (!gc->direction_input)
gc->direction_input = s3c_gpiolib_input;
if (!gc->direction_output)
gc->direction_output = s3c_gpiolib_output;
if (!gc->set)
gc->set = s3c_gpiolib_set;
if (!gc->get)
gc->get = s3c_gpiolib_get;
#ifdef CONFIG_PM
if (chip->pm != NULL) {
if (!chip->pm->save || !chip->pm->resume)
printk(KERN_ERR "gpio: %s has missing PM functions\n",
gc->label);
} else
printk(KERN_ERR "gpio: %s has no PM function\n", gc->label);
#endif
/* gpiochip_add() prints own failure message on error. */
ret = gpiochip_add(gc);
if (ret >= 0)
s3c_gpiolib_track(chip);
}
int samsung_gpiolib_to_irq(struct gpio_chip *chip, unsigned int offset)
{
struct s3c_gpio_chip *s3c_chip = container_of(chip,
struct s3c_gpio_chip, chip);
return s3c_chip->irq_base + offset;
}