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 <linux/export.h>
  19 #include <asm/hardware/iop3xx.h>
  20
  21 void gpio_line_config(int line, int direction)
  22 {
  23         unsigned long flags;
  24
  25         local_irq_save(flags);
  26         if (direction == GPIO_IN) {
  27                 *IOP3XX_GPOE |= 1 << line;
  28         } else if (direction == GPIO_OUT) {
  29                 *IOP3XX_GPOE &= ~(1 << line);
  30         }
  31         local_irq_restore(flags);
  32 }
  33 EXPORT_SYMBOL(gpio_line_config);
  34
  35 int gpio_line_get(int line)
  36 {
  37         return !!(*IOP3XX_GPID & (1 << line));
  38 }
  39 EXPORT_SYMBOL(gpio_line_get);
  40
  41 void gpio_line_set(int line, int value)
  42 {
  43         unsigned long flags;
  44
  45         local_irq_save(flags);
  46         if (value == GPIO_LOW) {
  47                 *IOP3XX_GPOD &= ~(1 << line);
  48         } else if (value == GPIO_HIGH) {
  49                 *IOP3XX_GPOD |= 1 << line;
  50         }
  51         local_irq_restore(flags);
  52 }
  53 EXPORT_SYMBOL(gpio_line_set);
  54
  55 static int iop3xx_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  56 {
  57         gpio_line_config(gpio, GPIO_IN);
  58         return 0;
  59 }
  60
  61 static int iop3xx_gpio_direction_output(struct gpio_chip *chip, unsigned gpio, int level)
  62 {
  63         gpio_line_set(gpio, level);
  64         gpio_line_config(gpio, GPIO_OUT);
  65         return 0;
  66 }
  67
  68 static int iop3xx_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  69 {
  70         return gpio_line_get(gpio);
  71 }
  72
  73 static void iop3xx_gpio_set_value(struct gpio_chip *chip, unsigned gpio, int value)
  74 {
  75         gpio_line_set(gpio, value);
  76 }
  77
  78 static struct gpio_chip iop3xx_chip = {
  79         .label                  = "iop3xx",
  80         .direction_input        = iop3xx_gpio_direction_input,
  81         .get                    = iop3xx_gpio_get_value,
  82         .direction_output       = iop3xx_gpio_direction_output,
  83         .set                    = iop3xx_gpio_set_value,
  84         .base                   = 0,
  85         .ngpio                  = IOP3XX_N_GPIOS,
  86 };
  87
  88 static int __init iop3xx_gpio_setup(void)
  89 {
  90         return gpiochip_add(&iop3xx_chip);
  91 }
  92 arch_initcall(iop3xx_gpio_setup);