LXR linux/drivers/base/regmap/regmap-spi.c

   1/*
   2 * Register map access API - SPI support
   3 *
   4 * Copyright 2011 Wolfson Microelectronics plc
   5 *
   6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2 as
  10 * published by the Free Software Foundation.
  11 */
  12
  13#include <linux/regmap.h>
  14#include <linux/spi/spi.h>
  15#include <linux/module.h>
  16
  17#include "internal.h"
  18
  19struct regmap_async_spi {
  20        struct regmap_async core;
  21        struct spi_message m;
  22        struct spi_transfer t[2];
  23};
  24
  25static void regmap_spi_complete(void *data)
  26{
  27        struct regmap_async_spi *async = data;
  28
  29        regmap_async_complete_cb(&async->core, async->m.status);
  30}
  31
  32static int regmap_spi_write(void *context, const void *data, size_t count)
  33{
  34        struct device *dev = context;
  35        struct spi_device *spi = to_spi_device(dev);
  36
  37        return spi_write(spi, data, count);
  38}
  39
  40static int regmap_spi_gather_write(void *context,
  41                                   const void *reg, size_t reg_len,
  42                                   const void *val, size_t val_len)
  43{
  44        struct device *dev = context;
  45        struct spi_device *spi = to_spi_device(dev);
  46        struct spi_message m;
  47        struct spi_transfer t[2] = { { .tx_buf = reg, .len = reg_len, },
  48                                     { .tx_buf = val, .len = val_len, }, };
  49
  50        spi_message_init(&m);
  51        spi_message_add_tail(&t[0], &m);
  52        spi_message_add_tail(&t[1], &m);
  53
  54        return spi_sync(spi, &m);
  55}
  56
  57static int regmap_spi_async_write(void *context,
  58                                  const void *reg, size_t reg_len,
  59                                  const void *val, size_t val_len,
  60                                  struct regmap_async *a)
  61{
  62        struct regmap_async_spi *async = container_of(a,
  63                                                      struct regmap_async_spi,
  64                                                      core);
  65        struct device *dev = context;
  66        struct spi_device *spi = to_spi_device(dev);
  67
  68        async->t[0].tx_buf = reg;
  69        async->t[0].len = reg_len;
  70        async->t[1].tx_buf = val;
  71        async->t[1].len = val_len;
  72
  73        spi_message_init(&async->m);
  74        spi_message_add_tail(&async->t[0], &async->m);
  75        if (val)
  76                spi_message_add_tail(&async->t[1], &async->m);
  77
  78        async->m.complete = regmap_spi_complete;
  79        async->m.context = async;
  80
  81        return spi_async(spi, &async->m);
  82}
  83
  84static struct regmap_async *regmap_spi_async_alloc(void)
  85{
  86        struct regmap_async_spi *async_spi;
  87
  88        async_spi = kzalloc(sizeof(*async_spi), GFP_KERNEL);
  89        if (!async_spi)
  90                return NULL;
  91
  92        return &async_spi->core;
  93}
  94
  95static int regmap_spi_read(void *context,
  96                           const void *reg, size_t reg_size,
  97                           void *val, size_t val_size)
  98{
  99        struct device *dev = context;
 100        struct spi_device *spi = to_spi_device(dev);
 101
 102        return spi_write_then_read(spi, reg, reg_size, val, val_size);
 103}
 104
 105static struct regmap_bus regmap_spi = {
 106        .write = regmap_spi_write,
 107        .gather_write = regmap_spi_gather_write,
 108        .async_write = regmap_spi_async_write,
 109        .async_alloc = regmap_spi_async_alloc,
 110        .read = regmap_spi_read,
 111        .read_flag_mask = 0x80,
 112        .reg_format_endian_default = REGMAP_ENDIAN_BIG,
 113        .val_format_endian_default = REGMAP_ENDIAN_BIG,
 114};
 115
 116/**
 117 * regmap_init_spi(): Initialise register map
 118 *
 119 * @spi: Device that will be interacted with
 120 * @config: Configuration for register map
 121 *
 122 * The return value will be an ERR_PTR() on error or a valid pointer to
 123 * a struct regmap.
 124 */
 125struct regmap *regmap_init_spi(struct spi_device *spi,
 126                               const struct regmap_config *config)
 127{
 128        return regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
 129}
 130EXPORT_SYMBOL_GPL(regmap_init_spi);
 131
 132/**
 133 * devm_regmap_init_spi(): Initialise register map
 134 *
 135 * @spi: Device that will be interacted with
 136 * @config: Configuration for register map
 137 *
 138 * The return value will be an ERR_PTR() on error or a valid pointer
 139 * to a struct regmap.  The map will be automatically freed by the
 140 * device management code.
 141 */
 142struct regmap *devm_regmap_init_spi(struct spi_device *spi,
 143                                    const struct regmap_config *config)
 144{
 145        return devm_regmap_init(&spi->dev, &regmap_spi, &spi->dev, config);
 146}
 147EXPORT_SYMBOL_GPL(devm_regmap_init_spi);
 148
 149MODULE_LICENSE("GPL");
 150