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