release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/mach-davinci/include/mach/gpio.h

   1 /*
   2  * TI DaVinci GPIO Support
   3  *
   4  * Copyright (c) 2006 David Brownell
   5  * Copyright (c) 2007, MontaVista Software, Inc. <source@mvista.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 #ifndef __DAVINCI_GPIO_H
  14 #define __DAVINCI_GPIO_H
  15
  16 #include <linux/io.h>
  17 #include <linux/spinlock.h>
  18
  19 #include <asm-generic/gpio.h>
  20
  21 #include <mach/irqs.h>
  22 #include <mach/common.h>
  23
  24 #define DAVINCI_GPIO_BASE 0x01C67000
  25
  26 enum davinci_gpio_type {
  27         GPIO_TYPE_DAVINCI = 0,
  28         GPIO_TYPE_TNETV107X,
  29 };
  30
  31 #define GPIO(X)         (X)             /* 0 <= X <= (DAVINCI_N_GPIO - 1) */
  32
  33 /* Convert GPIO signal to GPIO pin number */
  34 #define GPIO_TO_PIN(bank, gpio) (16 * (bank) + (gpio))
  35
  36 struct davinci_gpio_controller {
  37         struct gpio_chip        chip;
  38         int                     irq_base;
  39         spinlock_t              lock;
  40         void __iomem            *regs;
  41         void __iomem            *set_data;
  42         void __iomem            *clr_data;
  43         void __iomem            *in_data;
  44 };
  45
  46 /* The __gpio_to_controller() and __gpio_mask() functions inline to constants
  47  * with constant parameters; or in outlined code they execute at runtime.
  48  *
  49  * You'd access the controller directly when reading or writing more than
  50  * one gpio value at a time, and to support wired logic where the value
  51  * being driven by the cpu need not match the value read back.
  52  *
  53  * These are NOT part of the cross-platform GPIO interface
  54  */
  55 static inline struct davinci_gpio_controller *
  56 __gpio_to_controller(unsigned gpio)
  57 {
  58         struct davinci_gpio_controller *ctlrs = davinci_soc_info.gpio_ctlrs;
  59         int index = gpio / 32;
  60
  61         if (!ctlrs || index >= davinci_soc_info.gpio_ctlrs_num)
  62                 return NULL;
  63
  64         return ctlrs + index;
  65 }
  66
  67 static inline u32 __gpio_mask(unsigned gpio)
  68 {
  69         return 1 << (gpio % 32);
  70 }
  71
  72 /*
  73  * The get/set/clear functions will inline when called with constant
  74  * parameters referencing built-in GPIOs, for low-overhead bitbanging.
  75  *
  76  * gpio_set_value() will inline only on traditional Davinci style controllers
  77  * with distinct set/clear registers.
  78  *
  79  * Otherwise, calls with variable parameters or referencing external
  80  * GPIOs (e.g. on GPIO expander chips) use outlined functions.
  81  */
  82 static inline void gpio_set_value(unsigned gpio, int value)
  83 {
  84         if (__builtin_constant_p(value) && gpio < davinci_soc_info.gpio_num) {
  85                 struct davinci_gpio_controller *ctlr;
  86                 u32                             mask;
  87
  88                 ctlr = __gpio_to_controller(gpio);
  89
  90                 if (ctlr->set_data != ctlr->clr_data) {
  91                         mask = __gpio_mask(gpio);
  92                         if (value)
  93                                 __raw_writel(mask, ctlr->set_data);
  94                         else
  95                                 __raw_writel(mask, ctlr->clr_data);
  96                         return;
  97                 }
  98         }
  99
 100         __gpio_set_value(gpio, value);
 101 }
 102
 103 /* Returns zero or nonzero; works for gpios configured as inputs OR
 104  * as outputs, at least for built-in GPIOs.
 105  *
 106  * NOTE: for built-in GPIOs, changes in reported values are synchronized
 107  * to the GPIO clock.  This is easily seen after calling gpio_set_value()
 108  * and then immediately gpio_get_value(), where the gpio_get_value() will
 109  * return the old value until the GPIO clock ticks and the new value gets
 110  * latched.
 111  */
 112 static inline int gpio_get_value(unsigned gpio)
 113 {
 114         struct davinci_gpio_controller *ctlr;
 115
 116         if (!__builtin_constant_p(gpio) || gpio >= davinci_soc_info.gpio_num)
 117                 return __gpio_get_value(gpio);
 118
 119         ctlr = __gpio_to_controller(gpio);
 120         return __gpio_mask(gpio) & __raw_readl(ctlr->in_data);
 121 }
 122
 123 static inline int gpio_cansleep(unsigned gpio)
 124 {
 125         if (__builtin_constant_p(gpio) && gpio < davinci_soc_info.gpio_num)
 126                 return 0;
 127         else
 128                 return __gpio_cansleep(gpio);
 129 }
 130
 131 static inline int gpio_to_irq(unsigned gpio)
 132 {
 133         return __gpio_to_irq(gpio);
 134 }
 135
 136 static inline int irq_to_gpio(unsigned irq)
 137 {
 138         /* don't support the reverse mapping */
 139         return -ENOSYS;
 140 }
 141
 142 #endif                          /* __DAVINCI_GPIO_H */