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_byte_reg_read(void *context, unsigned int reg,
  11                                         unsigned int *val)
  12 {
  13         struct slim_device *sdev = context;
  14         int v;
  15
  16         v = slim_readb(sdev, reg);
  17
  18         if (v < 0)
  19                 return v;
  20
  21         *val = v;
  22
  23         return 0;
  24 }
  25
  26 static int regmap_slimbus_byte_reg_write(void *context, unsigned int reg,
  27                                          unsigned int val)
  28 {
  29         struct slim_device *sdev = context;
  30
  31         return slim_writeb(sdev, reg, val);
  32 }
  33
  34 static struct regmap_bus regmap_slimbus_bus = {
  35         .reg_write = regmap_slimbus_byte_reg_write,
  36         .reg_read = regmap_slimbus_byte_reg_read,
  37         .reg_format_endian_default = REGMAP_ENDIAN_LITTLE,
  38         .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
  39 };
  40
  41 static const struct regmap_bus *regmap_get_slimbus(struct slim_device *slim,
  42                                         const struct regmap_config *config)
  43 {
  44         if (config->val_bits == 8 && config->reg_bits == 16)
  45                 return &regmap_slimbus_bus;
  46
  47         return ERR_PTR(-ENOTSUPP);
  48 }
  49
  50 struct regmap *__regmap_init_slimbus(struct slim_device *slimbus,
  51                                      const struct regmap_config *config,
  52                                      struct lock_class_key *lock_key,
  53                                      const char *lock_name)
  54 {
  55         const struct regmap_bus *bus = regmap_get_slimbus(slimbus, config);
  56
  57         if (IS_ERR(bus))
  58                 return ERR_CAST(bus);
  59
  60         return __regmap_init(&slimbus->dev, bus, &slimbus->dev, config,
  61                              lock_key, lock_name);
  62 }
  63 EXPORT_SYMBOL_GPL(__regmap_init_slimbus);
  64
  65 struct regmap *__devm_regmap_init_slimbus(struct slim_device *slimbus,
  66                                           const struct regmap_config *config,
  67                                           struct lock_class_key *lock_key,
  68                                           const char *lock_name)
  69 {
  70         const struct regmap_bus *bus = regmap_get_slimbus(slimbus, config);
  71
  72         if (IS_ERR(bus))
  73                 return ERR_CAST(bus);
  74
  75         return __devm_regmap_init(&slimbus->dev, bus, &slimbus, config,
  76                                   lock_key, lock_name);
  77 }
  78 EXPORT_SYMBOL_GPL(__devm_regmap_init_slimbus);
  79
  80 MODULE_LICENSE("GPL v2");