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 <asm-generic/gpio.h>
  17
  18 #define __ARM_GPIOLIB_COMPLEX
  19
  20 /* The inline versions use the static inlines in the driver header */
  21 #include "gpio-davinci.h"
  22
  23 /*
  24  * The get/set/clear functions will inline when called with constant
  25  * parameters referencing built-in GPIOs, for low-overhead bitbanging.
  26  *
  27  * gpio_set_value() will inline only on traditional Davinci style controllers
  28  * with distinct set/clear registers.
  29  *
  30  * Otherwise, calls with variable parameters or referencing external
  31  * GPIOs (e.g. on GPIO expander chips) use outlined functions.
  32  */
  33 static inline void gpio_set_value(unsigned gpio, int value)
  34 {
  35         if (__builtin_constant_p(value) && gpio < davinci_soc_info.gpio_num) {
  36                 struct davinci_gpio_controller *ctlr;
  37                 u32                             mask;
  38
  39                 ctlr = __gpio_to_controller(gpio);
  40
  41                 if (ctlr->set_data != ctlr->clr_data) {
  42                         mask = __gpio_mask(gpio);
  43                         if (value)
  44                                 __raw_writel(mask, ctlr->set_data);
  45                         else
  46                                 __raw_writel(mask, ctlr->clr_data);
  47                         return;
  48                 }
  49         }
  50
  51         __gpio_set_value(gpio, value);
  52 }
  53
  54 /* Returns zero or nonzero; works for gpios configured as inputs OR
  55  * as outputs, at least for built-in GPIOs.
  56  *
  57  * NOTE: for built-in GPIOs, changes in reported values are synchronized
  58  * to the GPIO clock.  This is easily seen after calling gpio_set_value()
  59  * and then immediately gpio_get_value(), where the gpio_get_value() will
  60  * return the old value until the GPIO clock ticks and the new value gets
  61  * latched.
  62  */
  63 static inline int gpio_get_value(unsigned gpio)
  64 {
  65         struct davinci_gpio_controller *ctlr;
  66
  67         if (!__builtin_constant_p(gpio) || gpio >= davinci_soc_info.gpio_num)
  68                 return __gpio_get_value(gpio);
  69
  70         ctlr = __gpio_to_controller(gpio);
  71         return __gpio_mask(gpio) & __raw_readl(ctlr->in_data);
  72 }
  73
  74 static inline int gpio_cansleep(unsigned gpio)
  75 {
  76         if (__builtin_constant_p(gpio) && gpio < davinci_soc_info.gpio_num)
  77                 return 0;
  78         else
  79                 return __gpio_cansleep(gpio);
  80 }
  81
  82 static inline int irq_to_gpio(unsigned irq)
  83 {
  84         /* don't support the reverse mapping */
  85         return -ENOSYS;
  86 }
  87
  88 #endif                          /* __DAVINCI_GPIO_H */