linux-stable-rt/arch/xtensa/variants/s6000/gpio.c

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/*
* s6000 gpio driver
*
* Copyright (c) 2009 emlix GmbH
* Authors: Oskar Schirmer <os@emlix.com>
* Johannes Weiner <jw@emlix.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <variant/hardware.h>
#define S6_GPIO_DATA 0x000
#define S6_GPIO_IS 0x404
#define S6_GPIO_IBE 0x408
#define S6_GPIO_IEV 0x40C
#define S6_GPIO_IE 0x410
#define S6_GPIO_RIS 0x414
#define S6_GPIO_MIS 0x418
#define S6_GPIO_IC 0x41C
#define S6_GPIO_AFSEL 0x420
#define S6_GPIO_DIR 0x800
#define S6_GPIO_BANK(nr) ((nr) * 0x1000)
#define S6_GPIO_MASK(nr) (4 << (nr))
#define S6_GPIO_OFFSET(nr) \
(S6_GPIO_BANK((nr) >> 3) + S6_GPIO_MASK((nr) & 7))
static int direction_input(struct gpio_chip *chip, unsigned int off)
{
writeb(0, S6_REG_GPIO + S6_GPIO_DIR + S6_GPIO_OFFSET(off));
return 0;
}
static int get(struct gpio_chip *chip, unsigned int off)
{
return readb(S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}
static int direction_output(struct gpio_chip *chip, unsigned int off, int val)
{
unsigned rel = S6_GPIO_OFFSET(off);
writeb(~0, S6_REG_GPIO + S6_GPIO_DIR + rel);
writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + rel);
return 0;
}
static void set(struct gpio_chip *chip, unsigned int off, int val)
{
writeb(val ? ~0 : 0, S6_REG_GPIO + S6_GPIO_DATA + S6_GPIO_OFFSET(off));
}
static struct gpio_chip gpiochip = {
.owner = THIS_MODULE,
.direction_input = direction_input,
.get = get,
.direction_output = direction_output,
.set = set,
.base = 0,
.ngpio = 24,
.can_sleep = 0, /* no blocking io needed */
.exported = 0, /* no exporting to userspace */
};
static int gpio_init(void)
{
return gpiochip_add(&gpiochip);
}
device_initcall(gpio_init);