/* arch/arm/plat-samsung/gpiolib.c
*
* Copyright 2008 Openmoko, Inc.
* Copyright 2008 Simtec Electronics
* Ben Dooks <ben@simtec.co.uk>
* http://armlinux.simtec.co.uk/
*
* Copyright (c) 2009 Samsung Electronics Co., Ltd.
* http://www.samsung.com/
*
* SAMSUNG - GPIOlib support
*
* 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/irq.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <plat/gpio-core.h>
#include <plat/gpio-cfg.h>
#include <plat/gpio-cfg-helpers.h>
#ifndef DEBUG_GPIO
#define gpio_dbg(x...) do { } while (0)
#else
#define gpio_dbg(x...) printk(KERN_DEBUG x)
#endif
/* The samsung_gpiolib_4bit routines are to control the gpio banks where
* the gpio configuration register (GPxCON) has 4 bits per GPIO, as the
* following example:
*
* base + 0x00: Control register, 4 bits per gpio
* gpio n: 4 bits starting at (4*n)
* 0000 = input, 0001 = output, others mean special-function
* base + 0x04: Data register, 1 bit per gpio
* bit n: data bit n
*
* Note, since the data register is one bit per gpio and is at base + 0x4
* we can use s3c_gpiolib_get and s3c_gpiolib_set to change the state of
* the output.
*/
static int samsung_gpiolib_4bit_input(struct gpio_chip *chip,
unsigned int offset)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
unsigned long con;
con = __raw_readl(base + GPIOCON_OFF);
con &= ~(0xf << con_4bit_shift(offset));
__raw_writel(con, base + GPIOCON_OFF);
gpio_dbg("%s: %p: CON now %08lx\n", __func__, base, con);
return 0;
}
static int samsung_gpiolib_4bit_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
unsigned long con;
unsigned long dat;
con = __raw_readl(base + GPIOCON_OFF);
con &= ~(0xf << con_4bit_shift(offset));
con |= 0x1 << con_4bit_shift(offset);
dat = __raw_readl(base + GPIODAT_OFF);
if (value)
dat |= 1 << offset;
else
dat &= ~(1 << offset);
__raw_writel(dat, base + GPIODAT_OFF);
__raw_writel(con, base + GPIOCON_OFF);
__raw_writel(dat, base + GPIODAT_OFF);
gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);
return 0;
}
/* The next set of routines are for the case where the GPIO configuration
* registers are 4 bits per GPIO but there is more than one register (the
* bank has more than 8 GPIOs.
*
* This case is the similar to the 4 bit case, but the registers are as
* follows:
*
* base + 0x00: Control register, 4 bits per gpio (lower 8 GPIOs)
* gpio n: 4 bits starting at (4*n)
* 0000 = input, 0001 = output, others mean special-function
* base + 0x04: Control register, 4 bits per gpio (up to 8 additions GPIOs)
* gpio n: 4 bits starting at (4*n)
* 0000 = input, 0001 = output, others mean special-function
* base + 0x08: Data register, 1 bit per gpio
* bit n: data bit n
*
* To allow us to use the s3c_gpiolib_get and s3c_gpiolib_set routines we
* store the 'base + 0x4' address so that these routines see the data
* register at ourchip->base + 0x04.
*/
static int samsung_gpiolib_4bit2_input(struct gpio_chip *chip,
unsigned int offset)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
void __iomem *regcon = base;
unsigned long con;
if (offset > 7)
offset -= 8;
else
regcon -= 4;
con = __raw_readl(regcon);
con &= ~(0xf << con_4bit_shift(offset));
__raw_writel(con, regcon);
gpio_dbg("%s: %p: CON %08lx\n", __func__, base, con);
return 0;
}
static int samsung_gpiolib_4bit2_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
void __iomem *base = ourchip->base;
void __iomem *regcon = base;
unsigned long con;
unsigned long dat;
unsigned con_offset = offset;
if (con_offset > 7)
con_offset -= 8;
else
regcon -= 4;
con = __raw_readl(regcon);
con &= ~(0xf << con_4bit_shift(con_offset));
con |= 0x1 << con_4bit_shift(con_offset);
dat = __raw_readl(base + GPIODAT_OFF);
if (value)
dat |= 1 << offset;
else
dat &= ~(1 << offset);
__raw_writel(dat, base + GPIODAT_OFF);
__raw_writel(con, regcon);
__raw_writel(dat, base + GPIODAT_OFF);
gpio_dbg("%s: %p: CON %08lx, DAT %08lx\n", __func__, base, con, dat);
return 0;
}
void __init samsung_gpiolib_add_4bit(struct s3c_gpio_chip *chip)
{
chip->chip.direction_input = samsung_gpiolib_4bit_input;
chip->chip.direction_output = samsung_gpiolib_4bit_output;
chip->pm = __gpio_pm(&s3c_gpio_pm_4bit);
}
void __init samsung_gpiolib_add_4bit2(struct s3c_gpio_chip *chip)
{
chip->chip.direction_input = samsung_gpiolib_4bit2_input;
chip->chip.direction_output = samsung_gpiolib_4bit2_output;
chip->pm = __gpio_pm(&s3c_gpio_pm_4bit);
}
void __init samsung_gpiolib_add_4bit_chips(struct s3c_gpio_chip *chip,
int nr_chips)
{
for (; nr_chips > 0; nr_chips--, chip++) {
samsung_gpiolib_add_4bit(chip);
s3c_gpiolib_add(chip);
}
}
void __init samsung_gpiolib_add_4bit2_chips(struct s3c_gpio_chip *chip,
int nr_chips)
{
for (; nr_chips > 0; nr_chips--, chip++) {
samsung_gpiolib_add_4bit2(chip);
s3c_gpiolib_add(chip);
}
}
