include/linux/regmap.h

   1 #ifndef __LINUX_REGMAP_H
   2 #define __LINUX_REGMAP_H
   3
   4 /*
   5  * Register map access API
   6  *
   7  * Copyright 2011 Wolfson Microelectronics plc
   8  *
   9  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License version 2 as
  13  * published by the Free Software Foundation.
  14  */
  15
  16 #include <linux/device.h>
  17 #include <linux/list.h>
  18
  19 struct module;
  20 struct i2c_client;
  21 struct spi_device;
  22
  23 /* An enum of all the supported cache types */
  24 enum regcache_type {
  25         REGCACHE_NONE,
  26         REGCACHE_INDEXED,
  27         REGCACHE_RBTREE,
  28         REGCACHE_LZO
  29 };
  30
  31 /**
  32  * Default value for a register.  We use an array of structs rather
  33  * than a simple array as many modern devices have very sparse
  34  * register maps.
  35  *
  36  * @reg: Register address.
  37  * @def: Register default value.
  38  */
  39 struct reg_default {
  40         unsigned int reg;
  41         unsigned int def;
  42 };
  43
  44 /**
  45  * Configuration for the register map of a device.
  46  *
  47  * @reg_bits: Number of bits in a register address, mandatory.
  48  * @val_bits: Number of bits in a register value, mandatory.
  49  *
  50  * @writeable_reg: Optional callback returning true if the register
  51  *                 can be written to.
  52  * @readable_reg: Optional callback returning true if the register
  53  *                can be read from.
  54  * @volatile_reg: Optional callback returning true if the register
  55  *                value can't be cached.
  56  * @precious_reg: Optional callback returning true if the rgister
  57  *                should not be read outside of a call from the driver
  58  *                (eg, a clear on read interrupt status register).
  59  *
  60  * @max_register: Optional, specifies the maximum valid register index.
  61  * @reg_defaults: Power on reset values for registers (for use with
  62  *                register cache support).
  63  * @num_reg_defaults: Number of elements in reg_defaults.
  64  *
  65  * @read_flag_mask: Mask to be set in the top byte of the register when doing
  66  *                  a read.
  67  * @write_flag_mask: Mask to be set in the top byte of the register when doing
  68  *                   a write. If both read_flag_mask and write_flag_mask are
  69  *                   empty the regmap_bus default masks are used.
  70  *
  71  * @cache_type: The actual cache type.
  72  * @reg_defaults_raw: Power on reset values for registers (for use with
  73  *                    register cache support).
  74  * @num_reg_defaults_raw: Number of elements in reg_defaults_raw.
  75  */
  76 struct regmap_config {
  77         int reg_bits;
  78         int val_bits;
  79
  80         bool (*writeable_reg)(struct device *dev, unsigned int reg);
  81         bool (*readable_reg)(struct device *dev, unsigned int reg);
  82         bool (*volatile_reg)(struct device *dev, unsigned int reg);
  83         bool (*precious_reg)(struct device *dev, unsigned int reg);
  84
  85         unsigned int max_register;
  86         struct reg_default *reg_defaults;
  87         unsigned int num_reg_defaults;
  88         enum regcache_type cache_type;
  89         const void *reg_defaults_raw;
  90         unsigned int num_reg_defaults_raw;
  91
  92         u8 read_flag_mask;
  93         u8 write_flag_mask;
  94 };
  95
  96 typedef int (*regmap_hw_write)(struct device *dev, const void *data,
  97                                size_t count);
  98 typedef int (*regmap_hw_gather_write)(struct device *dev,
  99                                       const void *reg, size_t reg_len,
 100                                       const void *val, size_t val_len);
 101 typedef int (*regmap_hw_read)(struct device *dev,
 102                               const void *reg_buf, size_t reg_size,
 103                               void *val_buf, size_t val_size);
 104
 105 /**
 106  * Description of a hardware bus for the register map infrastructure.
 107  *
 108  * @write: Write operation.
 109  * @gather_write: Write operation with split register/value, return -ENOTSUPP
 110  *                if not implemented  on a given device.
 111  * @read: Read operation.  Data is returned in the buffer used to transmit
 112  *         data.
 113  * @read_flag_mask: Mask to be set in the top byte of the register when doing
 114  *                  a read.
 115  */
 116 struct regmap_bus {
 117         regmap_hw_write write;
 118         regmap_hw_gather_write gather_write;
 119         regmap_hw_read read;
 120         u8 read_flag_mask;
 121 };
 122
 123 struct regmap *regmap_init(struct device *dev,
 124                            const struct regmap_bus *bus,
 125                            const struct regmap_config *config);
 126 struct regmap *regmap_init_i2c(struct i2c_client *i2c,
 127                                const struct regmap_config *config);
 128 struct regmap *regmap_init_spi(struct spi_device *dev,
 129                                const struct regmap_config *config);
 130
 131 void regmap_exit(struct regmap *map);
 132 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
 133 int regmap_raw_write(struct regmap *map, unsigned int reg,
 134                      const void *val, size_t val_len);
 135 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
 136 int regmap_raw_read(struct regmap *map, unsigned int reg,
 137                     void *val, size_t val_len);
 138 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 139                      size_t val_count);
 140 int regmap_update_bits(struct regmap *map, unsigned int reg,
 141                        unsigned int mask, unsigned int val);
 142
 143 int regcache_sync(struct regmap *map);
 144 void regcache_cache_only(struct regmap *map, bool enable);
 145 void regcache_cache_bypass(struct regmap *map, bool enable);
 146
 147 #endif