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