drivers/base/regmap/regmap-sdw.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright(c) 2015-17 Intel Corporation.
   3
   4 #include <linux/device.h>
   5 #include <linux/mod_devicetable.h>
   6 #include <linux/module.h>
   7 #include <linux/soundwire/sdw.h>
   8 #include "internal.h"
   9
  10 static int regmap_sdw_write(void *context, unsigned int reg, unsigned int val)
  11 {
  12         struct device *dev = context;
  13         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  14
  15         return sdw_write(slave, reg, val);
  16 }
  17
  18 static int regmap_sdw_read(void *context, unsigned int reg, unsigned int *val)
  19 {
  20         struct device *dev = context;
  21         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  22         int read;
  23
  24         read = sdw_read(slave, reg);
  25         if (read < 0)
  26                 return read;
  27
  28         *val = read;
  29         return 0;
  30 }
  31
  32 static struct regmap_bus regmap_sdw = {
  33         .reg_read = regmap_sdw_read,
  34         .reg_write = regmap_sdw_write,
  35         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  36         .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
  37 };
  38
  39 static int regmap_sdw_config_check(const struct regmap_config *config)
  40 {
  41         /* All register are 8-bits wide as per MIPI Soundwire 1.0 Spec */
  42         if (config->val_bits != 8)
  43                 return -ENOTSUPP;
  44
  45         /* Registers are 32 bits wide */
  46         if (config->reg_bits != 32)
  47                 return -ENOTSUPP;
  48
  49         if (config->pad_bits != 0)
  50                 return -ENOTSUPP;
  51
  52         return 0;
  53 }
  54
  55 struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
  56                                  const struct regmap_config *config,
  57                                  struct lock_class_key *lock_key,
  58                                  const char *lock_name)
  59 {
  60         int ret;
  61
  62         ret = regmap_sdw_config_check(config);
  63         if (ret)
  64                 return ERR_PTR(ret);
  65
  66         return __regmap_init(&sdw->dev, &regmap_sdw,
  67                         &sdw->dev, config, lock_key, lock_name);
  68 }
  69 EXPORT_SYMBOL_GPL(__regmap_init_sdw);
  70
  71 struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
  72                                       const struct regmap_config *config,
  73                                       struct lock_class_key *lock_key,
  74                                       const char *lock_name)
  75 {
  76         int ret;
  77
  78         ret = regmap_sdw_config_check(config);
  79         if (ret)
  80                 return ERR_PTR(ret);
  81
  82         return __devm_regmap_init(&sdw->dev, &regmap_sdw,
  83                         &sdw->dev, config, lock_key, lock_name);
  84 }
  85 EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw);
  86
  87 MODULE_DESCRIPTION("Regmap SoundWire Module");
  88 MODULE_LICENSE("GPL v2");