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 <[email protected]> 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 148