arch/powerpc/include/asm/mpc85xx_gpio.h

   1 /*
   2  * Copyright 2010 eXMeritus, A Boeing Company
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifndef POWERPC_ASM_MPC85XX_GPIO_H_
   8 #define POWERPC_ASM_MPC85XX_GPIO_H_
   9
  10 # include <asm/immap_85xx.h>
  11
  12 /*
  13  * The following internal functions are an MPC85XX-specific GPIO API which
  14  * allows setting and querying multiple GPIOs in a single operation.
  15  *
  16  * All of these look relatively large, but the arguments are almost always
  17  * constants, so they compile down to just a few instructions and a
  18  * memory-mapped IO operation or two.
  19  */
  20 static inline void mpc85xx_gpio_set(unsigned int mask,
  21                 unsigned int dir, unsigned int val)
  22 {
  23         ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR);
  24
  25         /* First mask off the unwanted parts of "dir" and "val" */
  26         dir &= mask;
  27         val &= mask;
  28
  29         /* Now read in the values we're supposed to preserve */
  30         dir |= (in_be32(&gpio->gpdir) & ~mask);
  31         val |= (in_be32(&gpio->gpdat) & ~mask);
  32
  33         /*
  34          * Poke the new output values first, then set the direction.  This
  35          * helps to avoid transient data when switching from input to output
  36          * and vice versa.
  37          */
  38         out_be32(&gpio->gpdat, val);
  39         out_be32(&gpio->gpdir, dir);
  40 }
  41
  42 static inline void mpc85xx_gpio_set_in(unsigned int gpios)
  43 {
  44         mpc85xx_gpio_set(gpios, 0x00000000, 0x00000000);
  45 }
  46
  47 static inline void mpc85xx_gpio_set_low(unsigned int gpios)
  48 {
  49         mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0x00000000);
  50 }
  51
  52 static inline void mpc85xx_gpio_set_high(unsigned int gpios)
  53 {
  54         mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0xFFFFFFFF);
  55 }
  56
  57 static inline unsigned int mpc85xx_gpio_get(unsigned int mask)
  58 {
  59         ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR);
  60
  61         /* Read the requested values */
  62         return in_be32(&gpio->gpdat) & mask;
  63 }
  64
  65 /*
  66  * These implement the generic Linux GPIO API on top of the other functions
  67  * in this header.
  68  */
  69 static inline int gpio_request(unsigned gpio, const char *label)
  70 {
  71         /* Compatibility shim */
  72         return 0;
  73 }
  74
  75 static inline int gpio_free(unsigned gpio)
  76 {
  77         /* Compatibility shim */
  78         return 0;
  79 }
  80
  81 static inline int gpio_direction_input(unsigned gpio)
  82 {
  83         mpc85xx_gpio_set_in(1U << gpio);
  84         return 0;
  85 }
  86
  87 static inline int gpio_direction_output(unsigned gpio, int value)
  88 {
  89         if (value)
  90                 mpc85xx_gpio_set_high(1U << gpio);
  91         else
  92                 mpc85xx_gpio_set_low(1U << gpio);
  93         return 0;
  94 }
  95
  96 static inline int gpio_get_value(unsigned gpio)
  97 {
  98         return !!mpc85xx_gpio_get(1U << gpio);
  99 }
 100
 101 static inline int gpio_set_value(unsigned gpio, int value)
 102 {
 103         if (value)
 104                 mpc85xx_gpio_set_high(1U << gpio);
 105         else
 106                 mpc85xx_gpio_set_low(1U << gpio);
 107         return 0;
 108 }
 109
 110 static inline int gpio_is_valid(int gpio)
 111 {
 112         return (gpio >= 0) && (gpio < 32);
 113 }
 114
 115 #endif /* not POWERPC_ASM_MPC85XX_GPIO_H_ */