arch/mips/loongson/common/gpio.c

   1 /*
   2  *  STLS2F GPIO Support
   3  *
   4  *  Copyright (c) 2008 Richard Liu,  STMicroelectronics  <richard.liu@st.com>
   5  *  Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>
   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
  10  *  (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/module.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/err.h>
  18 #include <asm/types.h>
  19 #include <loongson.h>
  20 #include <linux/gpio.h>
  21
  22 #define STLS2F_N_GPIO           4
  23 #define STLS2F_GPIO_IN_OFFSET   16
  24
  25 static DEFINE_SPINLOCK(gpio_lock);
  26
  27 static int ls2f_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  28 {
  29         u32 temp;
  30         u32 mask;
  31
  32         spin_lock(&gpio_lock);
  33         mask = 1 << gpio;
  34         temp = LOONGSON_GPIOIE;
  35         temp |= mask;
  36         LOONGSON_GPIOIE = temp;
  37         spin_unlock(&gpio_lock);
  38
  39         return 0;
  40 }
  41
  42 static int ls2f_gpio_direction_output(struct gpio_chip *chip,
  43                 unsigned gpio, int level)
  44 {
  45         u32 temp;
  46         u32 mask;
  47
  48         gpio_set_value(gpio, level);
  49         spin_lock(&gpio_lock);
  50         mask = 1 << gpio;
  51         temp = LOONGSON_GPIOIE;
  52         temp &= (~mask);
  53         LOONGSON_GPIOIE = temp;
  54         spin_unlock(&gpio_lock);
  55
  56         return 0;
  57 }
  58
  59 static int ls2f_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  60 {
  61         u32 val;
  62         u32 mask;
  63
  64         mask = 1 << (gpio + STLS2F_GPIO_IN_OFFSET);
  65         spin_lock(&gpio_lock);
  66         val = LOONGSON_GPIODATA;
  67         spin_unlock(&gpio_lock);
  68
  69         return (val & mask) != 0;
  70 }
  71
  72 static void ls2f_gpio_set_value(struct gpio_chip *chip,
  73                 unsigned gpio, int value)
  74 {
  75         u32 val;
  76         u32 mask;
  77
  78         mask = 1 << gpio;
  79
  80         spin_lock(&gpio_lock);
  81         val = LOONGSON_GPIODATA;
  82         if (value)
  83                 val |= mask;
  84         else
  85                 val &= (~mask);
  86         LOONGSON_GPIODATA = val;
  87         spin_unlock(&gpio_lock);
  88 }
  89
  90 static struct gpio_chip ls2f_chip = {
  91         .label                  = "ls2f",
  92         .direction_input        = ls2f_gpio_direction_input,
  93         .get                    = ls2f_gpio_get_value,
  94         .direction_output       = ls2f_gpio_direction_output,
  95         .set                    = ls2f_gpio_set_value,
  96         .base                   = 0,
  97         .ngpio                  = STLS2F_N_GPIO,
  98         .can_sleep              = false,
  99 };
 100
 101 static int __init ls2f_gpio_setup(void)
 102 {
 103         return gpiochip_add(&ls2f_chip);
 104 }
 105 arch_initcall(ls2f_gpio_setup);