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/*
* Author: Carlo Caione <carlo@carlocaione.org>
*
* Based on linux/arch/arm/mach-bcm2708/bcm2708_gpio.c
*
* 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.
*
*/
#include <common.h>
#include <errno.h>
#include <malloc.h>
#include <io.h>
#include <gpio.h>
#include <init.h>
#define GPIOFSEL(x) (0x00+(x)*4)
#define GPIOSET(x) (0x1c+(x)*4)
#define GPIOCLR(x) (0x28+(x)*4)
#define GPIOLEV(x) (0x34+(x)*4)
#define GPIOEDS(x) (0x40+(x)*4)
#define GPIOREN(x) (0x4c+(x)*4)
#define GPIOFEN(x) (0x58+(x)*4)
#define GPIOHEN(x) (0x64+(x)*4)
#define GPIOLEN(x) (0x70+(x)*4)
#define GPIOAREN(x) (0x7c+(x)*4)
#define GPIOAFEN(x) (0x88+(x)*4)
#define GPIOUD(x) (0x94+(x)*4)
#define GPIOUDCLK(x) (0x98+(x)*4)
enum {
GPIO_FSEL_INPUT, GPIO_FSEL_OUTPUT,
GPIO_FSEL_ALT5, GPIO_FSEL_ALT_4,
GPIO_FSEL_ALT0, GPIO_FSEL_ALT1,
GPIO_FSEL_ALT2, GPIO_FSEL_ALT3,
};
struct bcm2835_gpio_chip {
void __iomem *base;
struct gpio_chip chip;
};
static int bcm2835_set_function(struct gpio_chip *chip, unsigned gpio, int function)
{
struct bcm2835_gpio_chip *bcmgpio = container_of(chip, struct bcm2835_gpio_chip, chip);
void __iomem *base = bcmgpio->base;
unsigned gpiodir;
unsigned gpio_bank = gpio / 10;
unsigned gpio_field_offset = (gpio - 10 * gpio_bank) * 3;
gpiodir = readl(base + GPIOFSEL(gpio_bank));
gpiodir &= ~(7 << gpio_field_offset);
gpiodir |= function << gpio_field_offset;
writel(gpiodir, base + GPIOFSEL(gpio_bank));
gpiodir = readl(base + GPIOFSEL(gpio_bank));
return 0;
}
static void bcm2835_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
{
struct bcm2835_gpio_chip *bcmgpio = container_of(chip, struct bcm2835_gpio_chip, chip);
void __iomem *base = bcmgpio->base;
unsigned gpio_bank = gpio / 32;
unsigned gpio_field_offset = gpio % 32;
if (value)
writel(1 << gpio_field_offset, base + GPIOSET(gpio_bank));
else
writel(1 << gpio_field_offset, base + GPIOCLR(gpio_bank));
}
static int bcm2835_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
struct bcm2835_gpio_chip *bcmgpio = container_of(chip, struct bcm2835_gpio_chip, chip);
void __iomem *base = bcmgpio->base;
unsigned gpio_bank = gpio / 32;
unsigned gpio_field_offset = gpio % 32;
unsigned lev;
lev = readl(base + GPIOLEV(gpio_bank));
return 0x1 & (lev >> gpio_field_offset);
}
static int bcm2835_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
return bcm2835_set_function(chip, gpio, GPIO_FSEL_INPUT);
}
static int bcm2835_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int value)
{
bcm2835_set_function(chip, gpio, GPIO_FSEL_OUTPUT);
bcm2835_gpio_set_value(chip, gpio, value);
return 0;
}
static struct gpio_ops bcm2835_gpio_ops = {
.direction_input = bcm2835_gpio_direction_input,
.direction_output = bcm2835_gpio_direction_output,
.get = bcm2835_gpio_get_value,
.set = bcm2835_gpio_set_value,
};
static int bcm2835_gpio_probe(struct device_d *dev)
{
struct resource *iores;
struct bcm2835_gpio_chip *bcmgpio;
int ret;
bcmgpio = xzalloc(sizeof(*bcmgpio));
iores = dev_request_mem_resource(dev, 0);
if (IS_ERR(iores))
return PTR_ERR(iores);
bcmgpio->base = IOMEM(iores->start);
bcmgpio->chip.ops = &bcm2835_gpio_ops;
bcmgpio->chip.base = 0;
bcmgpio->chip.ngpio = 54;
bcmgpio->chip.dev = dev;
ret = gpiochip_add(&bcmgpio->chip);
if (ret) {
dev_err(dev, "couldn't add gpiochip, ret = %d\n", ret);
goto err;
}
dev_info(dev, "probed gpiochip%d with base %d\n", dev->id, bcmgpio->chip.base);
return 0;
err:
kfree(bcmgpio);
return ret;
}
static __maybe_unused struct of_device_id bcm2835_gpio_dt_ids[] = {
{
.compatible = "brcm,bcm2835-gpio",
}, {
/* sentinel */
}
};
static struct driver_d bcm2835_gpio_driver = {
.name = "bcm2835-gpio",
.probe = bcm2835_gpio_probe,
.of_compatible = DRV_OF_COMPAT(bcm2835_gpio_dt_ids),
};
static int bcm2835_gpio_add(void)
{
return platform_driver_register(&bcm2835_gpio_driver);
}
coredevice_initcall(bcm2835_gpio_add);
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