arch/arm/mach-ns9xxx/gpio.c

   1 /*
   2  * arch/arm/mach-ns9xxx/gpio.c
   3  *
   4  * Copyright (C) 2006,2007 by Digi International Inc.
   5  * All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or modify it
   8  * under the terms of the GNU General Public License version 2 as published by
   9  * the Free Software Foundation.
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/compiler.h>
  13 #include <linux/init.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/module.h>
  16 #include <linux/bitops.h>
  17
  18 #include <mach/gpio.h>
  19 #include <mach/processor.h>
  20 #include <mach/processor-ns9360.h>
  21 #include <asm/bug.h>
  22 #include <asm/types.h>
  23
  24 #include "gpio-ns9360.h"
  25
  26 #if defined(CONFIG_PROCESSOR_NS9360)
  27 #define GPIO_MAX 72
  28 #elif defined(CONFIG_PROCESSOR_NS9750)
  29 #define GPIO_MAX 49
  30 #endif
  31
  32 /* protects BBU_GCONFx and BBU_GCTRLx */
  33 static spinlock_t gpio_lock = __SPIN_LOCK_UNLOCKED(gpio_lock);
  34
  35 /* only access gpiores with atomic ops */
  36 static DECLARE_BITMAP(gpiores, GPIO_MAX + 1);
  37
  38 static inline int ns9xxx_valid_gpio(unsigned gpio)
  39 {
  40 #if defined(CONFIG_PROCESSOR_NS9360)
  41         if (processor_is_ns9360())
  42                 return gpio <= 72;
  43         else
  44 #endif
  45 #if defined(CONFIG_PROCESSOR_NS9750)
  46         if (processor_is_ns9750())
  47                 return gpio <= 49;
  48         else
  49 #endif
  50         {
  51                 BUG();
  52                 return 0;
  53         }
  54 }
  55
  56 int gpio_request(unsigned gpio, const char *label)
  57 {
  58         if (likely(ns9xxx_valid_gpio(gpio)))
  59                 return test_and_set_bit(gpio, gpiores) ? -EBUSY : 0;
  60         else
  61                 return -EINVAL;
  62 }
  63 EXPORT_SYMBOL(gpio_request);
  64
  65 void gpio_free(unsigned gpio)
  66 {
  67         might_sleep();
  68         clear_bit(gpio, gpiores);
  69         return;
  70 }
  71 EXPORT_SYMBOL(gpio_free);
  72
  73 int gpio_direction_input(unsigned gpio)
  74 {
  75         if (likely(ns9xxx_valid_gpio(gpio))) {
  76                 int ret = -EINVAL;
  77                 unsigned long flags;
  78
  79                 spin_lock_irqsave(&gpio_lock, flags);
  80 #if defined(CONFIG_PROCESSOR_NS9360)
  81                 if (processor_is_ns9360())
  82                         ret = __ns9360_gpio_configure(gpio, 0, 0, 3);
  83                 else
  84 #endif
  85                         BUG();
  86
  87                 spin_unlock_irqrestore(&gpio_lock, flags);
  88
  89                 return ret;
  90
  91         } else
  92                 return -EINVAL;
  93 }
  94 EXPORT_SYMBOL(gpio_direction_input);
  95
  96 int gpio_direction_output(unsigned gpio, int value)
  97 {
  98         if (likely(ns9xxx_valid_gpio(gpio))) {
  99                 int ret = -EINVAL;
 100                 unsigned long flags;
 101
 102                 gpio_set_value(gpio, value);
 103
 104                 spin_lock_irqsave(&gpio_lock, flags);
 105 #if defined(CONFIG_PROCESSOR_NS9360)
 106                 if (processor_is_ns9360())
 107                         ret = __ns9360_gpio_configure(gpio, 1, 0, 3);
 108                 else
 109 #endif
 110                         BUG();
 111
 112                 spin_unlock_irqrestore(&gpio_lock, flags);
 113
 114                 return ret;
 115         } else
 116                 return -EINVAL;
 117 }
 118 EXPORT_SYMBOL(gpio_direction_output);
 119
 120 int gpio_get_value(unsigned gpio)
 121 {
 122 #if defined(CONFIG_PROCESSOR_NS9360)
 123         if (processor_is_ns9360())
 124                 return ns9360_gpio_get_value(gpio);
 125         else
 126 #endif
 127         {
 128                 BUG();
 129                 return -EINVAL;
 130         }
 131 }
 132 EXPORT_SYMBOL(gpio_get_value);
 133
 134 void gpio_set_value(unsigned gpio, int value)
 135 {
 136         unsigned long flags;
 137         spin_lock_irqsave(&gpio_lock, flags);
 138 #if defined(CONFIG_PROCESSOR_NS9360)
 139         if (processor_is_ns9360())
 140                 ns9360_gpio_set_value(gpio, value);
 141         else
 142 #endif
 143                 BUG();
 144
 145         spin_unlock_irqrestore(&gpio_lock, flags);
 146 }
 147 EXPORT_SYMBOL(gpio_set_value);