drivers/gpio/spear_gpio.c

   1 /*
   2  * Copyright (C) 2012 Stefan Roese <sr@denx.de>
   3  *
   4  * See file CREDITS for list of people who contributed to this
   5  * project.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as
   9  * published by the Free Software Foundation; either version 2 of
  10  * the License, or (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  20  * MA 02111-1307 USA
  21  */
  22
  23 /*
  24  * Driver for SPEAr600 GPIO controller
  25  */
  26
  27 #include <common.h>
  28 #include <asm/arch/hardware.h>
  29 #include <asm/gpio.h>
  30 #include <asm/io.h>
  31 #include <errno.h>
  32
  33 static int gpio_direction(unsigned gpio,
  34                           enum gpio_direction direction)
  35 {
  36         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  37         u32 val;
  38
  39         val = readl(&regs->gpiodir);
  40
  41         if (direction == GPIO_DIRECTION_OUT)
  42                 val |= 1 << gpio;
  43         else
  44                 val &= ~(1 << gpio);
  45
  46         writel(val, &regs->gpiodir);
  47
  48         return 0;
  49 }
  50
  51 int gpio_set_value(unsigned gpio, int value)
  52 {
  53         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  54
  55         writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
  56
  57         return 0;
  58 }
  59
  60 int gpio_get_value(unsigned gpio)
  61 {
  62         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  63         u32 val;
  64
  65         val = readl(&regs->gpiodata[DATA_REG_ADDR(gpio)]);
  66
  67         return !!val;
  68 }
  69
  70 int gpio_request(unsigned gpio, const char *label)
  71 {
  72         if (gpio >= SPEAR_GPIO_COUNT)
  73                 return -EINVAL;
  74
  75         return 0;
  76 }
  77
  78 int gpio_free(unsigned gpio)
  79 {
  80         return 0;
  81 }
  82
  83 void gpio_toggle_value(unsigned gpio)
  84 {
  85         gpio_set_value(gpio, !gpio_get_value(gpio));
  86 }
  87
  88 int gpio_direction_input(unsigned gpio)
  89 {
  90         return gpio_direction(gpio, GPIO_DIRECTION_IN);
  91 }
  92
  93 int gpio_direction_output(unsigned gpio, int value)
  94 {
  95         int ret = gpio_direction(gpio, GPIO_DIRECTION_OUT);
  96
  97         if (ret < 0)
  98                 return ret;
  99
 100         gpio_set_value(gpio, value);
 101         return 0;
 102 }