include/asm-arm/arch-davinci/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 <asm/hardware.h>
  18
  19 /*
  20  * basic gpio routines
  21  *
  22  * board-specific init should be done by arch/.../.../board-XXX.c (maybe
  23  * initializing banks together) rather than boot loaders; kexec() won't
  24  * go through boot loaders.
  25  *
  26  * the gpio clock will be turned on when gpios are used, and you may also
  27  * need to pay attention to PINMUX0 and PINMUX1 to be sure those pins are
  28  * used as gpios, not with other peripherals.
  29  *
  30  * GPIOs are numbered 0..(DAVINCI_N_GPIO-1).  For documentation, and maybe
  31  * for later updates, code should write GPIO(N) or:
  32  *  - GPIOV18(N) for 1.8V pins, N in 0..53; same as GPIO(0)..GPIO(53)
  33  *  - GPIOV33(N) for 3.3V pins, N in 0..17; same as GPIO(54)..GPIO(70)
  34  *
  35  * For GPIO IRQs use gpio_to_irq(GPIO(N)) or gpio_to_irq(GPIOV33(N)) etc
  36  * for now, that's != GPIO(N)
  37  */
  38 #define GPIO(X)         (X)             /* 0 <= X <= 70 */
  39 #define GPIOV18(X)      (X)             /* 1.8V i/o; 0 <= X <= 53 */
  40 #define GPIOV33(X)      ((X)+54)        /* 3.3V i/o; 0 <= X <= 17 */
  41
  42 struct gpio_controller {
  43         u32     dir;
  44         u32     out_data;
  45         u32     set_data;
  46         u32     clr_data;
  47         u32     in_data;
  48         u32     set_rising;
  49         u32     clr_rising;
  50         u32     set_falling;
  51         u32     clr_falling;
  52         u32     intstat;
  53 };
  54
  55 /* The __gpio_to_controller() and __gpio_mask() functions inline to constants
  56  * with constant parameters; or in outlined code they execute at runtime.
  57  *
  58  * You'd access the controller directly when reading or writing more than
  59  * one gpio value at a time, and to support wired logic where the value
  60  * being driven by the cpu need not match the value read back.
  61  *
  62  * These are NOT part of the cross-platform GPIO interface
  63  */
  64 static inline struct gpio_controller *__iomem
  65 __gpio_to_controller(unsigned gpio)
  66 {
  67         void *__iomem ptr;
  68
  69         if (gpio < 32)
  70                 ptr = (void *__iomem)IO_ADDRESS(DAVINCI_GPIO_BASE + 0x10);
  71         else if (gpio < 64)
  72                 ptr = (void *__iomem)IO_ADDRESS(DAVINCI_GPIO_BASE + 0x38);
  73         else if (gpio < DAVINCI_N_GPIO)
  74                 ptr = (void *__iomem)IO_ADDRESS(DAVINCI_GPIO_BASE + 0x60);
  75         else
  76                 ptr = NULL;
  77         return ptr;
  78 }
  79
  80 static inline u32 __gpio_mask(unsigned gpio)
  81 {
  82         return 1 << (gpio % 32);
  83 }
  84
  85 /* The get/set/clear functions will inline when called with constant
  86  * parameters, for low-overhead bitbanging.  Illegal constant parameters
  87  * cause link-time errors.
  88  *
  89  * Otherwise, calls with variable parameters use outlined functions.
  90  */
  91 extern int __error_inval_gpio(void);
  92
  93 extern void __gpio_set(unsigned gpio, int value);
  94 extern int __gpio_get(unsigned gpio);
  95
  96 static inline void gpio_set_value(unsigned gpio, int value)
  97 {
  98         if (__builtin_constant_p(value)) {
  99                 struct gpio_controller  *__iomem g;
 100                 u32                     mask;
 101
 102                 if (gpio >= DAVINCI_N_GPIO)
 103                         __error_inval_gpio();
 104
 105                 g = __gpio_to_controller(gpio);
 106                 mask = __gpio_mask(gpio);
 107                 if (value)
 108                         __raw_writel(mask, &g->set_data);
 109                 else
 110                         __raw_writel(mask, &g->clr_data);
 111                 return;
 112         }
 113
 114         __gpio_set(gpio, value);
 115 }
 116
 117 /* Returns zero or nonzero; works for gpios configured as inputs OR
 118  * as outputs.
 119  *
 120  * NOTE: changes in reported values are synchronized to the GPIO clock.
 121  * This is most easily seen after calling gpio_set_value() and then immediatly
 122  * gpio_get_value(), where the gpio_get_value() would return the old value
 123  * until the GPIO clock ticks and the new value gets latched.
 124  */
 125
 126 static inline int gpio_get_value(unsigned gpio)
 127 {
 128         struct gpio_controller *__iomem g;
 129
 130         if (!__builtin_constant_p(gpio))
 131                 return __gpio_get(gpio);
 132
 133         if (gpio >= DAVINCI_N_GPIO)
 134                 return __error_inval_gpio();
 135
 136         g = __gpio_to_controller(gpio);
 137         return !!(__gpio_mask(gpio) & __raw_readl(&g->in_data));
 138 }
 139
 140 /* powerup default direction is IN */
 141 extern int gpio_direction_input(unsigned gpio);
 142 extern int gpio_direction_output(unsigned gpio, int value);
 143
 144 #include <asm-generic/gpio.h>   /* cansleep wrappers */
 145
 146 extern int gpio_request(unsigned gpio, const char *tag);
 147 extern void gpio_free(unsigned gpio);
 148
 149 static inline int gpio_to_irq(unsigned gpio)
 150 {
 151         return DAVINCI_N_AINTC_IRQ + gpio;
 152 }
 153
 154 static inline int irq_to_gpio(unsigned irq)
 155 {
 156         return irq - DAVINCI_N_AINTC_IRQ;
 157 }
 158
 159 #endif                          /* __DAVINCI_GPIO_H */