LXR uboot/drivers/gpio/s3c2440

   1/*
   2 * Copyright (C) 2012
   3 * Gabriel Huau <contact@huau-gabriel.fr>
   4 *
   5 * See file CREDITS for list of people who contributed to this
   6 * project.
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License as
  10 * published by the Free Software Foundation; either version 2 of
  11 * the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21 * MA 02111-1307 USA
  22 */
  23#include <common.h>
  24#include <asm/arch/s3c2440.h>
  25#include <asm/gpio.h>
  26#include <asm/io.h>
  27
  28#define GPIO_INPUT  0x0
  29#define GPIO_OUTPUT 0x1
  30
  31/* 0x4 means that we want DAT and not CON register */
  32#define GPIO_PORT(x)    ((((x) >> 5) & 0x3) + 0x4)
  33#define GPIO_BIT(x)             ((x) & 0x3f)
  34
  35/*
  36 * It's how we calculate the full port address
  37 * We have to get the number of the port + 1 (Port A is at 0x56000001 ...)
  38 * We move it at the second digit, and finally we add 0x4 because we want
  39 * to modify GPIO DAT and not CON
  40 */
  41#define GPIO_FULLPORT(x) (S3C24X0_GPIO_BASE | ((GPIO_PORT(gpio) + 1) << 1))
  42
  43int gpio_set_value(unsigned gpio, int value)
  44{
  45        unsigned l = readl(GPIO_FULLPORT(gpio));
  46        unsigned bit;
  47        unsigned port = GPIO_FULLPORT(gpio);
  48
  49        /*
  50         * All GPIO Port have a configuration on
  51         * 2 bits excepted the first GPIO (A) which
  52         * have only 1 bit of configuration.
  53         */
  54        if (!GPIO_PORT(gpio))
  55                bit = (0x1 << GPIO_BIT(gpio));
  56        else
  57                bit = (0x3 << GPIO_BIT(gpio));
  58
  59        if (value)
  60                l |= bit;
  61        else
  62                l &= ~bit;
  63
  64        return writel(port, l);
  65}
  66
  67int gpio_get_value(unsigned gpio)
  68{
  69        unsigned l = readl(GPIO_FULLPORT(gpio));
  70
  71        if (GPIO_PORT(gpio) == 0) /* PORT A */
  72                return (l >> GPIO_BIT(gpio)) & 0x1;
  73        return (l >> GPIO_BIT(gpio)) & 0x3;
  74}
  75
  76int gpio_request(unsigned gpio, const char *label)
  77{
  78        return 0;
  79}
  80
  81int gpio_free(unsigned gpio)
  82{
  83        return 0;
  84}
  85
  86int gpio_direction_input(unsigned gpio)
  87{
  88        return writel(GPIO_FULLPORT(gpio), GPIO_INPUT << GPIO_BIT(gpio));
  89}
  90
  91int gpio_direction_output(unsigned gpio, int value)
  92{
  93        writel(GPIO_FULLPORT(gpio), GPIO_OUTPUT << GPIO_BIT(gpio));
  94        return gpio_set_value(gpio, value);
  95}
  96