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linux/arch/arm/plat-s3c/gpio.c
Ben Dooks d87964c460 [ARM] S3C: GPIO PM core GPIOlib integration
Move the GPIO suspend/resume support inline with the gpiolib support
so that it will work with both the S3C24XX and S3C64XX series.

The s3c_gpio_chip is extended to have a pm callback and a save block
to keep the state of the GPIO over suspend, and the code from the
s3c24xx implementation is added to a new common file.

The suspend process now uses the list of registered chips to go through
saving and restoring each one as appropriate, using the pm callback to
select the appropriate routine depending on the type of control register
present.

This change also means that any additional GPIO added should not require
changes to the PM.

Signed-off-by: Ben Dooks <ben-linux@fluff.org>
2009-05-07 11:04:56 +01:00

157 lines
3.5 KiB
C

/* 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 <mach/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;
local_irq_save(flags);
con = __raw_readl(base + 0x00);
con &= ~(3 << (offset * 2));
__raw_writel(con, base + 0x00);
local_irq_restore(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;
local_irq_save(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);
local_irq_restore(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;
local_irq_save(flags);
dat = __raw_readl(base + 0x04);
dat &= ~(1 << offset);
if (value)
dat |= 1 << offset;
__raw_writel(dat, base + 0x04);
local_irq_restore(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);
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);
}