drivers/base/regmap/regmap-slimbus.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (c) 2017, Linaro Ltd.
   3
   4 #include <linux/regmap.h>
   5 #include <linux/slimbus.h>
   6 #include <linux/module.h>
   7
   8 #include "internal.h"
   9
  10 static int regmap_slimbus_write(void *context, const void *data, size_t count)
  11 {
  12         struct slim_device *sdev = context;
  13
  14         return slim_write(sdev, *(u16 *)data, count - 2, (u8 *)data + 2);
  15 }
  16
  17 static int regmap_slimbus_read(void *context, const void *reg, size_t reg_size,
  18                                void *val, size_t val_size)
  19 {
  20         struct slim_device *sdev = context;
  21
  22         return slim_read(sdev, *(u16 *)reg, val_size, val);
  23 }
  24
  25 static struct regmap_bus regmap_slimbus_bus = {
  26         .write = regmap_slimbus_write,
  27         .read = regmap_slimbus_read,
  28         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  29         .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
  30 };
  31
  32 static const struct regmap_bus *regmap_get_slimbus(struct slim_device *slim,
  33                                         const struct regmap_config *config)
  34 {
  35         if (config->val_bits == 8 && config->reg_bits == 16)
  36                 return &regmap_slimbus_bus;
  37
  38         return ERR_PTR(-ENOTSUPP);
  39 }
  40
  41 struct regmap *__regmap_init_slimbus(struct slim_device *slimbus,
  42                                      const struct regmap_config *config,
  43                                      struct lock_class_key *lock_key,
  44                                      const char *lock_name)
  45 {
  46         const struct regmap_bus *bus = regmap_get_slimbus(slimbus, config);
  47
  48         if (IS_ERR(bus))
  49                 return ERR_CAST(bus);
  50
  51         return __regmap_init(&slimbus->dev, bus, &slimbus->dev, config,
  52                              lock_key, lock_name);
  53 }
  54 EXPORT_SYMBOL_GPL(__regmap_init_slimbus);
  55
  56 struct regmap *__devm_regmap_init_slimbus(struct slim_device *slimbus,
  57                                           const struct regmap_config *config,
  58                                           struct lock_class_key *lock_key,
  59                                           const char *lock_name)
  60 {
  61         const struct regmap_bus *bus = regmap_get_slimbus(slimbus, config);
  62
  63         if (IS_ERR(bus))
  64                 return ERR_CAST(bus);
  65
  66         return __devm_regmap_init(&slimbus->dev, bus, &slimbus, config,
  67                                   lock_key, lock_name);
  68 }
  69 EXPORT_SYMBOL_GPL(__devm_regmap_init_slimbus);
  70
  71 MODULE_LICENSE("GPL v2");