LXR linux/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 <asm-generic/gpio.h>
  18
  19#include <mach/irqs.h>
  20#include <mach/common.h>
  21
  22#define DAVINCI_GPIO_BASE 0x01C67000
  23
  24/*
  25 * basic gpio routines
  26 *
  27 * board-specific init should be done by arch/.../.../board-XXX.c (maybe
  28 * initializing banks together) rather than boot loaders; kexec() won't
  29 * go through boot loaders.
  30 *
  31 * the gpio clock will be turned on when gpios are used, and you may also
  32 * need to pay attention to PINMUX registers to be sure those pins are
  33 * used as gpios, not with other peripherals.
  34 *
  35 * On-chip GPIOs are numbered 0..(DAVINCI_N_GPIO-1).  For documentation,
  36 * and maybe for later updates, code may write GPIO(N).  These may be
  37 * all 1.8V signals, all 3.3V ones, or a mix of the two.  A given chip
  38 * may not support all the GPIOs in that range.
  39 *
  40 * GPIOs can also be on external chips, numbered after the ones built-in
  41 * to the DaVinci chip.  For now, they won't be usable as IRQ sources.
  42 */
  43#define GPIO(X)         (X)             /* 0 <= X <= (DAVINCI_N_GPIO - 1) */
  44
  45/* Convert GPIO signal to GPIO pin number */
  46#define GPIO_TO_PIN(bank, gpio) (16 * (bank) + (gpio))
  47
  48struct gpio_controller {
  49        u32     dir;
  50        u32     out_data;
  51        u32     set_data;
  52        u32     clr_data;
  53        u32     in_data;
  54        u32     set_rising;
  55        u32     clr_rising;
  56        u32     set_falling;
  57        u32     clr_falling;
  58        u32     intstat;
  59};
  60
  61/* The __gpio_to_controller() and __gpio_mask() functions inline to constants
  62 * with constant parameters; or in outlined code they execute at runtime.
  63 *
  64 * You'd access the controller directly when reading or writing more than
  65 * one gpio value at a time, and to support wired logic where the value
  66 * being driven by the cpu need not match the value read back.
  67 *
  68 * These are NOT part of the cross-platform GPIO interface
  69 */
  70static inline struct gpio_controller *__iomem
  71__gpio_to_controller(unsigned gpio)
  72{
  73        void *__iomem ptr;
  74        void __iomem *base = davinci_soc_info.gpio_base;
  75
  76        if (gpio < 32 * 1)
  77                ptr = base + 0x10;
  78        else if (gpio < 32 * 2)
  79                ptr = base + 0x38;
  80        else if (gpio < 32 * 3)
  81                ptr = base + 0x60;
  82        else if (gpio < 32 * 4)
  83                ptr = base + 0x88;
  84        else if (gpio < 32 * 5)
  85                ptr = base + 0xb0;
  86        else
  87                ptr = NULL;
  88        return ptr;
  89}
  90
  91static inline u32 __gpio_mask(unsigned gpio)
  92{
  93        return 1 << (gpio % 32);
  94}
  95
  96/* The get/set/clear functions will inline when called with constant
  97 * parameters referencing built-in GPIOs, for low-overhead bitbanging.
  98 *
  99 * Otherwise, calls with variable parameters or referencing external
 100 * GPIOs (e.g. on GPIO expander chips) use outlined functions.
 101 */
 102static inline void gpio_set_value(unsigned gpio, int value)
 103{
 104        if (__builtin_constant_p(value) && gpio < DAVINCI_N_GPIO) {
 105                struct gpio_controller  *__iomem g;
 106                u32                     mask;
 107
 108                g = __gpio_to_controller(gpio);
 109                mask = __gpio_mask(gpio);
 110                if (value)
 111                        __raw_writel(mask, &g->set_data);
 112                else
 113                        __raw_writel(mask, &g->clr_data);
 114                return;
 115        }
 116
 117        __gpio_set_value(gpio, value);
 118}
 119
 120/* Returns zero or nonzero; works for gpios configured as inputs OR
 121 * as outputs, at least for built-in GPIOs.
 122 *
 123 * NOTE: for built-in GPIOs, changes in reported values are synchronized
 124 * to the GPIO clock.  This is easily seen after calling gpio_set_value()
 125 * and then immediately gpio_get_value(), where the gpio_get_value() will
 126 * return the old value until the GPIO clock ticks and the new value gets
 127 * latched.
 128 */
 129static inline int gpio_get_value(unsigned gpio)
 130{
 131        struct gpio_controller  *__iomem g;
 132
 133        if (!__builtin_constant_p(gpio) || gpio >= DAVINCI_N_GPIO)
 134                return __gpio_get_value(gpio);
 135
 136        g = __gpio_to_controller(gpio);
 137        return __gpio_mask(gpio) & __raw_readl(&g->in_data);
 138}
 139
 140static inline int gpio_cansleep(unsigned gpio)
 141{
 142        if (__builtin_constant_p(gpio) && gpio < DAVINCI_N_GPIO)
 143                return 0;
 144        else
 145                return __gpio_cansleep(gpio);
 146}
 147
 148static inline int gpio_to_irq(unsigned gpio)
 149{
 150        return __gpio_to_irq(gpio);
 151}
 152
 153static inline int irq_to_gpio(unsigned irq)
 154{
 155        /* don't support the reverse mapping */
 156        return -ENOSYS;
 157}
 158
 159#endif                          /* __DAVINCI_GPIO_H */
 160