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/*
* Copyright (c) 2014-2015, Linaro Ltd and Contributors. All rights reserved.
* Copyright (c) 2014-2015, Hisilicon Ltd and Contributors. All rights reserved.
*
* GPIO driver for PL061
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of ARM nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <console.h>
#include <debug.h>
#include <errno.h>
#include <gpio.h>
#include <mmio.h>
#define MAX_GPIO_DEVICES 32
#define GPIOS_PER_DEV 8
#define GPIO_DIR 0x400
#define BIT(nr) (1UL << (nr))
struct gpio_device_t {
unsigned int base[MAX_GPIO_DEVICES];
unsigned int count;
};
static struct gpio_device_t gpio_dev;
/* return 0 for failure */
static unsigned int find_gc_base(unsigned int gpio)
{
int gc;
gc = gpio / GPIOS_PER_DEV;
if (gc >= gpio_dev.count)
return 0;
return gpio_dev.base[gc];
}
int gpio_direction_input(unsigned int gpio)
{
unsigned int gc_base, offset, data;
gc_base = find_gc_base(gpio);
if (!gc_base)
return -EINVAL;
offset = gpio % GPIOS_PER_DEV;
data = mmio_read_8(gc_base + GPIO_DIR);
data &= ~(1 << offset);
mmio_write_8(gc_base + GPIO_DIR, data);
return 0;
}
int gpio_direction_output(unsigned int gpio)
{
unsigned int gc_base, offset, data;
gc_base = find_gc_base(gpio);
if (!gc_base)
return -EINVAL;
offset = gpio % 8;
data = mmio_read_8(gc_base + GPIO_DIR);
data |= 1 << offset;
mmio_write_8(gc_base + GPIO_DIR, data);
return 0;
}
int gpio_get_value(unsigned int gpio)
{
unsigned int gc_base, offset;
gc_base = find_gc_base(gpio);
if (!gc_base)
return -EINVAL;
offset = gpio % 8;
return !!mmio_read_8(gc_base + (BIT(offset + 2)));
}
int gpio_set_value(unsigned int gpio, unsigned int value)
{
unsigned int gc_base, offset;
gc_base = find_gc_base(gpio);
if (!gc_base)
return -EINVAL;
offset = gpio % 8;
mmio_write_8(gc_base + (BIT(offset + 2)), !!value << offset);
return 0;
}
int gpio_register_device(unsigned int base)
{
int i;
if (gpio_dev.count > MAX_GPIO_DEVICES)
return -EINVAL;
for (i = 0; i < gpio_dev.count; i++) {
if (gpio_dev.base[i] == base) {
WARN("%s: duplicated gpio base\n", __func__);
return -EINVAL;
}
}
gpio_dev.base[gpio_dev.count] = base;
gpio_dev.count++;
return 0;
}
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