LXR uboot/arch/powerpc/include/asm/mpc85xx

   1/*
   2 * Copyright 2010 eXMeritus, A Boeing Company
   3 *
   4 * This program is free software; you can redistribute it and/or
   5 * modify it under the terms of the GNU General Public License as
   6 * published by the Free Software Foundation; either version 2 of
   7 * the License, or (at your option) any later version.
   8 *
   9 * This program is distributed in the hope that it will be useful,
  10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 * GNU General Public License for more details.
  13 *
  14 * You should have received a copy of the GNU General Public License
  15 * along with this program; if not, write to the Free Software
  16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  17 * MA 02111-1307 USA
  18 */
  19
  20#ifndef POWERPC_ASM_MPC85XX_GPIO_H_
  21#define POWERPC_ASM_MPC85XX_GPIO_H_
  22
  23# include <asm/immap_85xx.h>
  24
  25/*
  26 * The following internal functions are an MPC85XX-specific GPIO API which
  27 * allows setting and querying multiple GPIOs in a single operation.
  28 *
  29 * All of these look relatively large, but the arguments are almost always
  30 * constants, so they compile down to just a few instructions and a
  31 * memory-mapped IO operation or two.
  32 */
  33static inline void mpc85xx_gpio_set(unsigned int mask,
  34                unsigned int dir, unsigned int val)
  35{
  36        ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
  37
  38        /* First mask off the unwanted parts of "dir" and "val" */
  39        dir &= mask;
  40        val &= mask;
  41
  42        /* Now read in the values we're supposed to preserve */
  43        dir |= (in_be32(&gpio->gpdir) & ~mask);
  44        val |= (in_be32(&gpio->gpdat) & ~mask);
  45
  46        /*
  47         * Poke the new output values first, then set the direction.  This
  48         * helps to avoid transient data when switching from input to output
  49         * and vice versa.
  50         */
  51        out_be32(&gpio->gpdat, val);
  52        out_be32(&gpio->gpdir, dir);
  53}
  54
  55static inline void mpc85xx_gpio_set_in(unsigned int gpios)
  56{
  57        mpc85xx_gpio_set(gpios, 0x00000000, 0x00000000);
  58}
  59
  60static inline void mpc85xx_gpio_set_low(unsigned int gpios)
  61{
  62        mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0x00000000);
  63}
  64
  65static inline void mpc85xx_gpio_set_high(unsigned int gpios)
  66{
  67        mpc85xx_gpio_set(gpios, 0xFFFFFFFF, 0xFFFFFFFF);
  68}
  69
  70static inline unsigned int mpc85xx_gpio_get(unsigned int mask)
  71{
  72        ccsr_gpio_t *gpio = (void *)(CONFIG_SYS_MPC85xx_GPIO_ADDR + 0xc00);
  73
  74        /* Read the requested values */
  75        return in_be32(&gpio->gpdat) & mask;
  76}
  77
  78/*
  79 * These implement the generic Linux GPIO API on top of the other functions
  80 * in this header.
  81 */
  82static inline int gpio_request(unsigned gpio, const char *label)
  83{
  84        /* Compatibility shim */
  85        return 0;
  86}
  87
  88static inline void gpio_free(unsigned gpio)
  89{
  90        /* Compatibility shim */
  91}
  92
  93static inline int gpio_direction_input(unsigned gpio)
  94{
  95        mpc85xx_gpio_set_in(1U << gpio);
  96        return 0;
  97}
  98
  99static inline int gpio_direction_output(unsigned gpio, int value)
 100{
 101        mpc85xx_gpio_set_low(1U << gpio);
 102        return 0;
 103}
 104
 105static inline int gpio_get_value(unsigned gpio)
 106{
 107        return !!mpc85xx_gpio_get(1U << gpio);
 108}
 109
 110static inline void gpio_set_value(unsigned gpio, int value)
 111{
 112        if (value)
 113                mpc85xx_gpio_set_high(1U << gpio);
 114        else
 115                mpc85xx_gpio_set_low(1U << gpio);
 116}
 117
 118static inline int gpio_is_valid(int gpio)
 119{
 120        return (gpio >= 0) && (gpio < 32);
 121}
 122
 123#endif /* not POWERPC_ASM_MPC85XX_GPIO_H_ */
 124