drivers/base/regmap/regmap-sdw-mbq.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright(c) 2020 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/soundwire/sdw_registers.h>
  10 #include "internal.h"
  11
  12 static int regmap_sdw_mbq_write(void *context, unsigned int reg, unsigned int val)
  13 {
  14         struct device *dev = context;
  15         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  16         int ret;
  17
  18         ret = sdw_write(slave, SDW_SDCA_MBQ_CTL(reg), (val >> 8) & 0xff);
  19         if (ret < 0)
  20                 return ret;
  21
  22         return sdw_write(slave, reg, val & 0xff);
  23 }
  24
  25 static int regmap_sdw_mbq_read(void *context, unsigned int reg, unsigned int *val)
  26 {
  27         struct device *dev = context;
  28         struct sdw_slave *slave = dev_to_sdw_dev(dev);
  29         int read0;
  30         int read1;
  31
  32         read0 = sdw_read(slave, reg);
  33         if (read0 < 0)
  34                 return read0;
  35
  36         read1 = sdw_read(slave, SDW_SDCA_MBQ_CTL(reg));
  37         if (read1 < 0)
  38                 return read1;
  39
  40         *val = (read1 << 8) | read0;
  41
  42         return 0;
  43 }
  44
  45 static struct regmap_bus regmap_sdw_mbq = {
  46         .reg_read = regmap_sdw_mbq_read,
  47         .reg_write = regmap_sdw_mbq_write,
  48         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  49         .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
  50 };
  51
  52 static int regmap_sdw_mbq_config_check(const struct regmap_config *config)
  53 {
  54         /* MBQ-based controls are only 16-bits for now */
  55         if (config->val_bits != 16)
  56                 return -ENOTSUPP;
  57
  58         /* Registers are 32 bits wide */
  59         if (config->reg_bits != 32)
  60                 return -ENOTSUPP;
  61
  62         if (config->pad_bits != 0)
  63                 return -ENOTSUPP;
  64
  65         return 0;
  66 }
  67
  68 struct regmap *__regmap_init_sdw_mbq(struct sdw_slave *sdw,
  69                                      const struct regmap_config *config,
  70                                      struct lock_class_key *lock_key,
  71                                      const char *lock_name)
  72 {
  73         int ret;
  74
  75         ret = regmap_sdw_mbq_config_check(config);
  76         if (ret)
  77                 return ERR_PTR(ret);
  78
  79         return __regmap_init(&sdw->dev, &regmap_sdw_mbq,
  80                         &sdw->dev, config, lock_key, lock_name);
  81 }
  82 EXPORT_SYMBOL_GPL(__regmap_init_sdw_mbq);
  83
  84 struct regmap *__devm_regmap_init_sdw_mbq(struct sdw_slave *sdw,
  85                                           const struct regmap_config *config,
  86                                           struct lock_class_key *lock_key,
  87                                           const char *lock_name)
  88 {
  89         int ret;
  90
  91         ret = regmap_sdw_mbq_config_check(config);
  92         if (ret)
  93                 return ERR_PTR(ret);
  94
  95         return __devm_regmap_init(&sdw->dev, &regmap_sdw_mbq,
  96                         &sdw->dev, config, lock_key, lock_name);
  97 }
  98 EXPORT_SYMBOL_GPL(__devm_regmap_init_sdw_mbq);
  99
 100 MODULE_DESCRIPTION("Regmap SoundWire MBQ Module");
 101 MODULE_LICENSE("GPL v2");