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/*
* Copyright (c) 2009 Wind River Systems, Inc.
* Tom Rix <Tom.Rix@windriver.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*
* This work is derived from the linux 2.6.27 kernel source
* To fetch, use the kernel repository
* git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
* Use the v2.6.27 tag.
*
* Below is the original's header including its copyright
*
* linux/arch/arm/plat-omap/gpio.c
*
* Support functions for OMAP GPIO
*
* Copyright (C) 2003-2005 Nokia Corporation
* Written by Juha Yrjölä <juha.yrjola@nokia.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.
*/
#include <common.h>
#include <asm/arch/gpio.h>
#include <asm/io.h>
#include <asm/errno.h>
#define OMAP_GPIO_DIR_OUT 0
#define OMAP_GPIO_DIR_IN 1
static inline const struct gpio_bank *get_gpio_bank(int gpio)
{
return &omap_gpio_bank[gpio >> 5];
}
static inline int get_gpio_index(int gpio)
{
return gpio & 0x1f;
}
static inline int gpio_valid(int gpio)
{
if (gpio < 0)
return -EINVAL;
if (gpio < 192)
return 0;
return -EINVAL;
}
static int check_gpio(int gpio)
{
if (gpio_valid(gpio) < 0) {
printf("ERROR : check_gpio: invalid GPIO %d\n", gpio);
return -EINVAL;
}
return 0;
}
static void _set_gpio_direction(const struct gpio_bank *bank, int gpio,
int is_input)
{
void *reg = bank->base;
u32 l;
switch (bank->method) {
case METHOD_GPIO_24XX:
reg += OMAP_GPIO_OE;
break;
default:
return;
}
l = __raw_readl(reg);
if (is_input)
l |= 1 << gpio;
else
l &= ~(1 << gpio);
__raw_writel(l, reg);
}
/**
* Get the direction of the GPIO by reading the GPIO_OE register
* corresponding to the specified bank.
*/
static int _get_gpio_direction(const struct gpio_bank *bank, int gpio)
{
void *reg = bank->base;
u32 v;
switch (bank->method) {
case METHOD_GPIO_24XX:
reg += OMAP_GPIO_OE;
break;
default:
return -EINVAL;
}
v = __raw_readl(reg);
if (v & (1 << gpio))
return OMAP_GPIO_DIR_IN;
else
return OMAP_GPIO_DIR_OUT;
}
static void _set_gpio_dataout(const struct gpio_bank *bank, int gpio,
int enable)
{
void *reg = bank->base;
u32 l = 0;
switch (bank->method) {
case METHOD_GPIO_24XX:
if (enable)
reg += OMAP_GPIO_SETDATAOUT;
else
reg += OMAP_GPIO_CLEARDATAOUT;
l = 1 << gpio;
break;
default:
printf("omap3-gpio unknown bank method %s %d\n",
__FILE__, __LINE__);
return;
}
__raw_writel(l, reg);
}
/**
* Set value of the specified gpio
*/
void gpio_set_value(int gpio, int value)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return;
bank = get_gpio_bank(gpio);
_set_gpio_dataout(bank, get_gpio_index(gpio), value);
}
/**
* Get value of the specified gpio
*/
int gpio_get_value(int gpio)
{
const struct gpio_bank *bank;
void *reg;
int input;
if (check_gpio(gpio) < 0)
return -EINVAL;
bank = get_gpio_bank(gpio);
reg = bank->base;
switch (bank->method) {
case METHOD_GPIO_24XX:
input = _get_gpio_direction(bank, get_gpio_index(gpio));
switch (input) {
case OMAP_GPIO_DIR_IN:
reg += OMAP_GPIO_DATAIN;
break;
case OMAP_GPIO_DIR_OUT:
reg += OMAP_GPIO_DATAOUT;
break;
default:
return -EINVAL;
}
break;
default:
return -EINVAL;
}
return (__raw_readl(reg)
& (1 << get_gpio_index(gpio))) != 0;
}
/**
* Set gpio direction as input
*/
int gpio_direction_input(unsigned gpio)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return -EINVAL;
bank = get_gpio_bank(gpio);
_set_gpio_direction(bank, get_gpio_index(gpio), 1);
return 0;
}
/**
* Set gpio direction as output
*/
int gpio_direction_output(unsigned gpio, int value)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return -EINVAL;
bank = get_gpio_bank(gpio);
_set_gpio_dataout(bank, get_gpio_index(gpio), value);
_set_gpio_direction(bank, get_gpio_index(gpio), 0);
return 0;
}
/**
* Request a gpio before using it.
*
* NOTE: Argument 'label' is unused.
*/
int gpio_request(int gpio, const char *label)
{
if (check_gpio(gpio) < 0)
return -EINVAL;
return 0;
}
/**
* Reset and free the gpio after using it.
*/
void gpio_free(unsigned gpio)
{
}
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