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 #include <linux/module.h>
  19
  20 struct i2c_client;
  21 struct spi_device;
  22
  23 /**
  24  * Default value for a register.  We use an array of structs rather
  25  * than a simple array as many modern devices have very sparse
  26  * register maps.
  27  *
  28  * @reg: Register address.
  29  * @def: Register default value.
  30  */
  31 struct reg_default {
  32         unsigned int reg;
  33         unsigned int def;
  34 };
  35
  36 /**
  37  * Configuration for the register map of a device.
  38  *
  39  * @reg_bits: Number of bits in a register address, mandatory.
  40  * @val_bits: Number of bits in a register value, mandatory.
  41  *
  42  * @writeable_reg: Optional callback returning true if the register
  43  *                 can be written to.
  44  * @readable_reg: Optional callback returning true if the register
  45  *                can be read from.
  46  * @volatile_reg: Optional callback returning true if the register
  47  *                value can't be cached.
  48  * @precious_reg: Optional callback returning true if the rgister
  49  *                should not be read outside of a call from the driver
  50  *                (eg, a clear on read interrupt status register).
  51  *
  52  * @max_register: Optional, specifies the maximum valid register index.
  53  * @reg_defaults: Power on reset values for registers (for use with
  54  *                register cache support).
  55  * @num_reg_defaults: Number of elements in reg_defaults.
  56  */
  57 struct regmap_config {
  58         int reg_bits;
  59         int val_bits;
  60
  61         bool (*writeable_reg)(struct device *dev, unsigned int reg);
  62         bool (*readable_reg)(struct device *dev, unsigned int reg);
  63         bool (*volatile_reg)(struct device *dev, unsigned int reg);
  64         bool (*precious_reg)(struct device *dev, unsigned int reg);
  65
  66         unsigned int max_register;
  67         struct reg_default *reg_defaults;
  68         int num_reg_defaults;
  69 };
  70
  71 typedef int (*regmap_hw_write)(struct device *dev, const void *data,
  72                                size_t count);
  73 typedef int (*regmap_hw_gather_write)(struct device *dev,
  74                                       const void *reg, size_t reg_len,
  75                                       const void *val, size_t val_len);
  76 typedef int (*regmap_hw_read)(struct device *dev,
  77                               const void *reg_buf, size_t reg_size,
  78                               void *val_buf, size_t val_size);
  79
  80 /**
  81  * Description of a hardware bus for the register map infrastructure.
  82  *
  83  * @write: Write operation.
  84  * @gather_write: Write operation with split register/value, return -ENOTSUPP
  85  *                if not implemented  on a given device.
  86  * @read: Read operation.  Data is returned in the buffer used to transmit
  87  *         data.
  88  * @owner: Module with the bus implementation, used to pin the implementation
  89  *         in memory.
  90  * @read_flag_mask: Mask to be set in the top byte of the register when doing
  91  *                  a read.
  92  */
  93 struct regmap_bus {
  94         regmap_hw_write write;
  95         regmap_hw_gather_write gather_write;
  96         regmap_hw_read read;
  97         struct module *owner;
  98         u8 read_flag_mask;
  99 };
 100
 101 struct regmap *regmap_init(struct device *dev,
 102                            const struct regmap_bus *bus,
 103                            const struct regmap_config *config);
 104 struct regmap *regmap_init_i2c(struct i2c_client *i2c,
 105                                const struct regmap_config *config);
 106 struct regmap *regmap_init_spi(struct spi_device *dev,
 107                                const struct regmap_config *config);
 108
 109 void regmap_exit(struct regmap *map);
 110 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
 111 int regmap_raw_write(struct regmap *map, unsigned int reg,
 112                      const void *val, size_t val_len);
 113 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
 114 int regmap_raw_read(struct regmap *map, unsigned int reg,
 115                     void *val, size_t val_len);
 116 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 117                      size_t val_count);
 118 int regmap_update_bits(struct regmap *map, unsigned int reg,
 119                        unsigned int mask, unsigned int val);
 120
 121 #endif