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 <linux/types.h>
  10 #include "internal.h"
  11
  12 static int regmap_sdw_write(void *context, const void *val_buf, size_t val_size)
  13 {
  14         struct device *dev = context;
  15         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  16         /* First word of buffer contains the destination address */
  17         u32 addr = le32_to_cpu(*(const __le32 *)val_buf);
  18         const u8 *val = val_buf;
  19
  20         return sdw_nwrite_no_pm(slave, addr, val_size - sizeof(addr), val + sizeof(addr));
  21 }
  22
  23 static int regmap_sdw_gather_write(void *context,
  24                                    const void *reg_buf, size_t reg_size,
  25                                    const void *val_buf, size_t val_size)
  26 {
  27         struct device *dev = context;
  28         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  29         u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);
  30
  31         return sdw_nwrite_no_pm(slave, addr, val_size, val_buf);
  32 }
  33
  34 static int regmap_sdw_read(void *context,
  35                            const void *reg_buf, size_t reg_size,
  36                            void *val_buf, size_t val_size)
  37 {
  38         struct device *dev = context;
  39         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  40         u32 addr = le32_to_cpu(*(const __le32 *)reg_buf);
  41
  42         return sdw_nread_no_pm(slave, addr, val_size, val_buf);
  43 }
  44
  45 static const struct regmap_bus regmap_sdw = {
  46         .write = regmap_sdw_write,
  47         .gather_write = regmap_sdw_gather_write,
  48         .read = regmap_sdw_read,
  49         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  50         .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
  51 };
  52
  53 static int regmap_sdw_config_check(const struct regmap_config *config)
  54 {
  55         /* Register addresses are 32 bits wide */
  56         if (config->reg_bits != 32)
  57                 return -ENOTSUPP;
  58
  59         if (config->pad_bits != 0)
  60                 return -ENOTSUPP;
  61
  62         /* Only bulk writes are supported not multi-register writes */
  63         if (config->can_multi_write)
  64                 return -ENOTSUPP;
  65
  66         return 0;
  67 }
  68
  69 struct regmap *__regmap_init_sdw(struct sdw_slave *sdw,
  70                                  const struct regmap_config *config,
  71                                  struct lock_class_key *lock_key,
  72                                  const char *lock_name)
  73 {
  74         int ret;
  75
  76         ret = regmap_sdw_config_check(config);
  77         if (ret)
  78                 return ERR_PTR(ret);
  79
  80         return __regmap_init(&sdw->dev, &regmap_sdw,
  81                         &sdw->dev, config, lock_key, lock_name);
  82 }
  83 EXPORT_SYMBOL_GPL(__regmap_init_sdw);
  84
  85 struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw,
  86                                       const struct regmap_config *config,
  87                                       struct lock_class_key *lock_key,
  88                                       const char *lock_name)
  89 {
  90         int ret;
  91
  92         ret = regmap_sdw_config_check(config);
  93         if (ret)
  94                 return ERR_PTR(ret);
  95
  96         return __devm_regmap_init(&sdw->dev, &regmap_sdw,
  97                         &sdw->dev, config, lock_key, lock_name);
  98 }
  99 EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw);
 100
 101 MODULE_DESCRIPTION("regmap SoundWire Module");
 102 MODULE_LICENSE("GPL v2");