arch/arm/plat-iop/gpio.c

   1 /*
   2  * arch/arm/plat-iop/gpio.c
   3  * GPIO handling for Intel IOP3xx processors.
   4  *
   5  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or (at
  10  * your option) any later version.
  11  */
  12
  13 #include <linux/device.h>
  14 #include <linux/init.h>
  15 #include <linux/types.h>
  16 #include <linux/errno.h>
  17 #include <linux/gpio.h>
  18 #include <asm/hardware/iop3xx.h>
  19
  20 void gpio_line_config(int line, int direction)
  21 {
  22         unsigned long flags;
  23
  24         local_irq_save(flags);
  25         if (direction == GPIO_IN) {
  26                 *IOP3XX_GPOE |= 1 << line;
  27         } else if (direction == GPIO_OUT) {
  28                 *IOP3XX_GPOE &= ~(1 << line);
  29         }
  30         local_irq_restore(flags);
  31 }
  32 EXPORT_SYMBOL(gpio_line_config);
  33
  34 int gpio_line_get(int line)
  35 {
  36         return !!(*IOP3XX_GPID & (1 << line));
  37 }
  38 EXPORT_SYMBOL(gpio_line_get);
  39
  40 void gpio_line_set(int line, int value)
  41 {
  42         unsigned long flags;
  43
  44         local_irq_save(flags);
  45         if (value == GPIO_LOW) {
  46                 *IOP3XX_GPOD &= ~(1 << line);
  47         } else if (value == GPIO_HIGH) {
  48                 *IOP3XX_GPOD |= 1 << line;
  49         }
  50         local_irq_restore(flags);
  51 }
  52 EXPORT_SYMBOL(gpio_line_set);
  53
  54 static int iop3xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  55 {
  56         gpio_line_config(gpio, GPIO_IN);
  57         return 0;
  58 }
  59
  60 static int iop3xx_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int level)
  61 {
  62         gpio_line_set(gpio, level);
  63         gpio_line_config(gpio, GPIO_OUT);
  64         return 0;
  65 }
  66
  67 static int iop3xx_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  68 {
  69         return gpio_line_get(gpio);
  70 }
  71
  72 static void iop3xx_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
  73 {
  74         gpio_line_set(gpio, value);
  75 }
  76
  77 static struct gpio_chip iop3xx_chip = {
  78         .label                  = "iop3xx",
  79         .direction_input        = iop3xx_gpio_direction_input,
  80         .get                    = iop3xx_gpio_get_value,
  81         .direction_output       = iop3xx_gpio_direction_output,
  82         .set                    = iop3xx_gpio_set_value,
  83         .base                   = 0,
  84         .ngpio                  = IOP3XX_N_GPIOS,
  85 };
  86
  87 static int __init iop3xx_gpio_setup(void)
  88 {
  89         return gpiochip_add(&iop3xx_chip);
  90 }
  91 arch_initcall(iop3xx_gpio_setup);