u-boot/drivers/gpio/omap_gpio.c

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/*
* Copyright (c) 2009 Wind River Systems, Inc.
* Tom Rix <Tom.Rix@windriver.com>
*
* SPDX-License-Identifier: GPL-2.0
*
* 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>
*/
#include <common.h>
#include <dm.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/errno.h>
#define OMAP_GPIO_DIR_OUT 0
#define OMAP_GPIO_DIR_IN 1
#ifdef CONFIG_DM_GPIO
#define GPIO_PER_BANK 32
struct gpio_bank {
/* TODO(sjg@chromium.org): Can we use a struct here? */
void *base; /* address of registers in physical memory */
enum gpio_method method;
};
#endif
static inline int get_gpio_index(int gpio)
{
return gpio & 0x1f;
}
int gpio_is_valid(int gpio)
{
return (gpio >= 0) && (gpio < OMAP_MAX_GPIO);
}
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 -1;
}
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);
}
static int _get_gpio_value(const struct gpio_bank *bank, int gpio)
{
void *reg = bank->base;
int input;
switch (bank->method) {
case METHOD_GPIO_24XX:
input = _get_gpio_direction(bank, 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 -1;
}
break;
default:
return -1;
}
return (__raw_readl(reg) & (1 << gpio)) != 0;
}
#ifndef CONFIG_DM_GPIO
static inline const struct gpio_bank *get_gpio_bank(int gpio)
{
return &omap_gpio_bank[gpio >> 5];
}
static int check_gpio(int gpio)
{
if (!gpio_is_valid(gpio)) {
printf("ERROR : check_gpio: invalid GPIO %d\n", gpio);
return -1;
}
return 0;
}
/**
* Set value of the specified gpio
*/
int gpio_set_value(unsigned gpio, int value)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return -1;
bank = get_gpio_bank(gpio);
_set_gpio_dataout(bank, get_gpio_index(gpio), value);
return 0;
}
/**
* Get value of the specified gpio
*/
int gpio_get_value(unsigned gpio)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return -1;
bank = get_gpio_bank(gpio);
return _get_gpio_value(bank, get_gpio_index(gpio));
}
/**
* Set gpio direction as input
*/
int gpio_direction_input(unsigned gpio)
{
const struct gpio_bank *bank;
if (check_gpio(gpio) < 0)
return -1;
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 -1;
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(unsigned gpio, const char *label)
{
if (check_gpio(gpio) < 0)
return -1;
return 0;
}
/**
* Reset and free the gpio after using it.
*/
int gpio_free(unsigned gpio)
{
return 0;
}
#else /* new driver model interface CONFIG_DM_GPIO */
/* set GPIO pin 'gpio' as an input */
static int omap_gpio_direction_input(struct udevice *dev, unsigned offset)
{
struct gpio_bank *bank = dev_get_priv(dev);
/* Configure GPIO direction as input. */
_set_gpio_direction(bank, offset, 1);
return 0;
}
/* set GPIO pin 'gpio' as an output, with polarity 'value' */
static int omap_gpio_direction_output(struct udevice *dev, unsigned offset,
int value)
{
struct gpio_bank *bank = dev_get_priv(dev);
_set_gpio_dataout(bank, offset, value);
_set_gpio_direction(bank, offset, 0);
return 0;
}
/* read GPIO IN value of pin 'gpio' */
static int omap_gpio_get_value(struct udevice *dev, unsigned offset)
{
struct gpio_bank *bank = dev_get_priv(dev);
return _get_gpio_value(bank, offset);
}
/* write GPIO OUT value to pin 'gpio' */
static int omap_gpio_set_value(struct udevice *dev, unsigned offset,
int value)
{
struct gpio_bank *bank = dev_get_priv(dev);
_set_gpio_dataout(bank, offset, value);
return 0;
}
static int omap_gpio_get_function(struct udevice *dev, unsigned offset)
{
struct gpio_bank *bank = dev_get_priv(dev);
/* GPIOF_FUNC is not implemented yet */
if (_get_gpio_direction(bank, offset) == OMAP_GPIO_DIR_OUT)
return GPIOF_OUTPUT;
else
return GPIOF_INPUT;
}
static const struct dm_gpio_ops gpio_omap_ops = {
.direction_input = omap_gpio_direction_input,
.direction_output = omap_gpio_direction_output,
.get_value = omap_gpio_get_value,
.set_value = omap_gpio_set_value,
.get_function = omap_gpio_get_function,
};
static int omap_gpio_probe(struct udevice *dev)
{
struct gpio_bank *bank = dev_get_priv(dev);
struct omap_gpio_platdata *plat = dev_get_platdata(dev);
struct gpio_dev_priv *uc_priv = dev->uclass_priv;
char name[18], *str;
sprintf(name, "GPIO%d_", plat->bank_index);
str = strdup(name);
if (!str)
return -ENOMEM;
uc_priv->bank_name = str;
uc_priv->gpio_count = GPIO_PER_BANK;
bank->base = (void *)plat->base;
bank->method = plat->method;
return 0;
}
U_BOOT_DRIVER(gpio_omap) = {
.name = "gpio_omap",
.id = UCLASS_GPIO,
.ops = &gpio_omap_ops,
.probe = omap_gpio_probe,
.priv_auto_alloc_size = sizeof(struct gpio_bank),
};
#endif /* CONFIG_DM_GPIO */