drivers/gpio/spear_gpio.c

   1 /*
   2  * Copyright (C) 2012 Stefan Roese <sr@denx.de>
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 /*
   8  * Driver for SPEAr600 GPIO controller
   9  */
  10
  11 #include <common.h>
  12 #include <asm/arch/hardware.h>
  13 #include <asm/gpio.h>
  14 #include <asm/io.h>
  15 #include <errno.h>
  16
  17 static int gpio_direction(unsigned gpio,
  18                           enum gpio_direction direction)
  19 {
  20         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  21         u32 val;
  22
  23         val = readl(&regs->gpiodir);
  24
  25         if (direction == GPIO_DIRECTION_OUT)
  26                 val |= 1 << gpio;
  27         else
  28                 val &= ~(1 << gpio);
  29
  30         writel(val, &regs->gpiodir);
  31
  32         return 0;
  33 }
  34
  35 int gpio_set_value(unsigned gpio, int value)
  36 {
  37         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  38
  39         writel(1 << gpio, &regs->gpiodata[DATA_REG_ADDR(gpio)]);
  40
  41         return 0;
  42 }
  43
  44 int gpio_get_value(unsigned gpio)
  45 {
  46         struct gpio_regs *regs = (struct gpio_regs *)CONFIG_GPIO_BASE;
  47         u32 val;
  48
  49         val = readl(&regs->gpiodata[DATA_REG_ADDR(gpio)]);
  50
  51         return !!val;
  52 }
  53
  54 int gpio_request(unsigned gpio, const char *label)
  55 {
  56         if (gpio >= SPEAR_GPIO_COUNT)
  57                 return -EINVAL;
  58
  59         return 0;
  60 }
  61
  62 int gpio_free(unsigned gpio)
  63 {
  64         return 0;
  65 }
  66
  67 void gpio_toggle_value(unsigned gpio)
  68 {
  69         gpio_set_value(gpio, !gpio_get_value(gpio));
  70 }
  71
  72 int gpio_direction_input(unsigned gpio)
  73 {
  74         return gpio_direction(gpio, GPIO_DIRECTION_IN);
  75 }
  76
  77 int gpio_direction_output(unsigned gpio, int value)
  78 {
  79         int ret = gpio_direction(gpio, GPIO_DIRECTION_OUT);
  80
  81         if (ret < 0)
  82                 return ret;
  83
  84         gpio_set_value(gpio, value);
  85         return 0;
  86 }