drivers/gpio/gpio-loongson.c

   1 /*
   2  *  Loongson-2F/3A/3B 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  *  Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>
   7  *  Copyright (c) 2014 Huacai Chen <chenhc@lemote.com>
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  */
  14
  15 #include <linux/kernel.h>
  16 #include <linux/init.h>
  17 #include <linux/module.h>
  18 #include <linux/spinlock.h>
  19 #include <linux/err.h>
  20 #include <asm/types.h>
  21 #include <loongson.h>
  22 #include <linux/gpio.h>
  23
  24 #define STLS2F_N_GPIO           4
  25 #define STLS3A_N_GPIO           16
  26
  27 #ifdef CONFIG_CPU_LOONGSON3
  28 #define LOONGSON_N_GPIO STLS3A_N_GPIO
  29 #else
  30 #define LOONGSON_N_GPIO STLS2F_N_GPIO
  31 #endif
  32
  33 #define LOONGSON_GPIO_IN_OFFSET 16
  34
  35 static DEFINE_SPINLOCK(gpio_lock);
  36
  37 static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  38 {
  39         u32 temp;
  40         u32 mask;
  41
  42         spin_lock(&gpio_lock);
  43         mask = 1 << gpio;
  44         temp = LOONGSON_GPIOIE;
  45         temp |= mask;
  46         LOONGSON_GPIOIE = temp;
  47         spin_unlock(&gpio_lock);
  48
  49         return 0;
  50 }
  51
  52 static int loongson_gpio_direction_output(struct gpio_chip *chip,
  53                 unsigned gpio, int level)
  54 {
  55         u32 temp;
  56         u32 mask;
  57
  58         gpio_set_value(gpio, level);
  59         spin_lock(&gpio_lock);
  60         mask = 1 << gpio;
  61         temp = LOONGSON_GPIOIE;
  62         temp &= (~mask);
  63         LOONGSON_GPIOIE = temp;
  64         spin_unlock(&gpio_lock);
  65
  66         return 0;
  67 }
  68
  69 static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  70 {
  71         u32 val;
  72         u32 mask;
  73
  74         mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET);
  75         spin_lock(&gpio_lock);
  76         val = LOONGSON_GPIODATA;
  77         spin_unlock(&gpio_lock);
  78
  79         return (val & mask) != 0;
  80 }
  81
  82 static void loongson_gpio_set_value(struct gpio_chip *chip,
  83                 unsigned gpio, int value)
  84 {
  85         u32 val;
  86         u32 mask;
  87
  88         mask = 1 << gpio;
  89
  90         spin_lock(&gpio_lock);
  91         val = LOONGSON_GPIODATA;
  92         if (value)
  93                 val |= mask;
  94         else
  95                 val &= (~mask);
  96         LOONGSON_GPIODATA = val;
  97         spin_unlock(&gpio_lock);
  98 }
  99
 100 static struct gpio_chip loongson_chip = {
 101         .label                  = "Loongson-gpio-chip",
 102         .direction_input        = loongson_gpio_direction_input,
 103         .get                    = loongson_gpio_get_value,
 104         .direction_output       = loongson_gpio_direction_output,
 105         .set                    = loongson_gpio_set_value,
 106         .base                   = 0,
 107         .ngpio                  = LOONGSON_N_GPIO,
 108         .can_sleep              = false,
 109 };
 110
 111 static int __init loongson_gpio_setup(void)
 112 {
 113         return gpiochip_add(&loongson_chip);
 114 }
 115 postcore_initcall(loongson_gpio_setup);