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