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
  19 struct regmap_async_spi {
  20         struct regmap_async core;
  21         struct spi_message m;
  22         struct spi_transfer t[2];
  23 };
  24
  25 static 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
  32 static 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
  40 static 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
  57 static 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
  84 static 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
  95 static 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
 105 static const 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 struct regmap *__regmap_init_spi(struct spi_device *spi,
 117                                  const struct regmap_config *config,
 118                                  struct lock_class_key *lock_key,
 119                                  const char *lock_name)
 120 {
 121         return __regmap_init(&spi->dev, &regmap_spi, &spi->dev, config,
 122                              lock_key, lock_name);
 123 }
 124 EXPORT_SYMBOL_GPL(__regmap_init_spi);
 125
 126 struct regmap *__devm_regmap_init_spi(struct spi_device *spi,
 127                                       const struct regmap_config *config,
 128                                       struct lock_class_key *lock_key,
 129                                       const char *lock_name)
 130 {
 131         return __devm_regmap_init(&spi->dev, &regmap_spi, &spi->dev, config,
 132                                   lock_key, lock_name);
 133 }
 134 EXPORT_SYMBOL_GPL(__devm_regmap_init_spi);
 135
 136 MODULE_LICENSE("GPL");