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