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_RBTREE,
  27         REGCACHE_COMPRESSED
  28 };
  29
  30 /**
  31  * Default value for a register.  We use an array of structs rather
  32  * than a simple array as many modern devices have very sparse
  33  * register maps.
  34  *
  35  * @reg: Register address.
  36  * @def: Register default value.
  37  */
  38 struct reg_default {
  39         unsigned int reg;
  40         unsigned int def;
  41 };
  42
  43 /**
  44  * Configuration for the register map of a device.
  45  *
  46  * @reg_bits: Number of bits in a register address, mandatory.
  47  * @pad_bits: Number of bits of padding between register and value.
  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 pad_bits;
  79         int val_bits;
  80
  81         bool (*writeable_reg)(struct device *dev, unsigned int reg);
  82         bool (*readable_reg)(struct device *dev, unsigned int reg);
  83         bool (*volatile_reg)(struct device *dev, unsigned int reg);
  84         bool (*precious_reg)(struct device *dev, unsigned int reg);
  85
  86         unsigned int max_register;
  87         const struct reg_default *reg_defaults;
  88         unsigned int num_reg_defaults;
  89         enum regcache_type cache_type;
  90         const void *reg_defaults_raw;
  91         unsigned int num_reg_defaults_raw;
  92
  93         u8 read_flag_mask;
  94         u8 write_flag_mask;
  95 };
  96
  97 typedef int (*regmap_hw_write)(struct device *dev, const void *data,
  98                                size_t count);
  99 typedef int (*regmap_hw_gather_write)(struct device *dev,
 100                                       const void *reg, size_t reg_len,
 101                                       const void *val, size_t val_len);
 102 typedef int (*regmap_hw_read)(struct device *dev,
 103                               const void *reg_buf, size_t reg_size,
 104                               void *val_buf, size_t val_size);
 105
 106 /**
 107  * Description of a hardware bus for the register map infrastructure.
 108  *
 109  * @write: Write operation.
 110  * @gather_write: Write operation with split register/value, return -ENOTSUPP
 111  *                if not implemented  on a given device.
 112  * @read: Read operation.  Data is returned in the buffer used to transmit
 113  *         data.
 114  * @read_flag_mask: Mask to be set in the top byte of the register when doing
 115  *                  a read.
 116  */
 117 struct regmap_bus {
 118         regmap_hw_write write;
 119         regmap_hw_gather_write gather_write;
 120         regmap_hw_read read;
 121         u8 read_flag_mask;
 122 };
 123
 124 struct regmap *regmap_init(struct device *dev,
 125                            const struct regmap_bus *bus,
 126                            const struct regmap_config *config);
 127 struct regmap *regmap_init_i2c(struct i2c_client *i2c,
 128                                const struct regmap_config *config);
 129 struct regmap *regmap_init_spi(struct spi_device *dev,
 130                                const struct regmap_config *config);
 131
 132 void regmap_exit(struct regmap *map);
 133 int regmap_reinit_cache(struct regmap *map,
 134                         const struct regmap_config *config);
 135 int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
 136 int regmap_raw_write(struct regmap *map, unsigned int reg,
 137                      const void *val, size_t val_len);
 138 int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
 139 int regmap_raw_read(struct regmap *map, unsigned int reg,
 140                     void *val, size_t val_len);
 141 int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
 142                      size_t val_count);
 143 int regmap_update_bits(struct regmap *map, unsigned int reg,
 144                        unsigned int mask, unsigned int val);
 145 int regmap_update_bits_check(struct regmap *map, unsigned int reg,
 146                              unsigned int mask, unsigned int val,
 147                              bool *change);
 148
 149 int regcache_sync(struct regmap *map);
 150 void regcache_cache_only(struct regmap *map, bool enable);
 151 void regcache_cache_bypass(struct regmap *map, bool enable);
 152 void regcache_mark_dirty(struct regmap *map);
 153
 154 /**
 155  * Description of an IRQ for the generic regmap irq_chip.
 156  *
 157  * @reg_offset: Offset of the status/mask register within the bank
 158  * @mask:       Mask used to flag/control the register.
 159  */
 160 struct regmap_irq {
 161         unsigned int reg_offset;
 162         unsigned int mask;
 163 };
 164
 165 /**
 166  * Description of a generic regmap irq_chip.  This is not intended to
 167  * handle every possible interrupt controller, but it should handle a
 168  * substantial proportion of those that are found in the wild.
 169  *
 170  * @name:        Descriptive name for IRQ controller.
 171  *
 172  * @status_base: Base status register address.
 173  * @mask_base:   Base mask register address.
 174  * @ack_base:    Base ack address.  If zero then the chip is clear on read.
 175  *
 176  * @num_regs:    Number of registers in each control bank.
 177  * @irqs:        Descriptors for individual IRQs.  Interrupt numbers are
 178  *               assigned based on the index in the array of the interrupt.
 179  * @num_irqs:    Number of descriptors.
 180  */
 181 struct regmap_irq_chip {
 182         const char *name;
 183
 184         unsigned int status_base;
 185         unsigned int mask_base;
 186         unsigned int ack_base;
 187
 188         int num_regs;
 189
 190         const struct regmap_irq *irqs;
 191         int num_irqs;
 192 };
 193
 194 struct regmap_irq_chip_data;
 195
 196 int regmap_add_irq_chip(struct regmap *map, int irq, int irq_flags,
 197                         int irq_base, struct regmap_irq_chip *chip,
 198                         struct regmap_irq_chip_data **data);
 199 void regmap_del_irq_chip(int irq, struct regmap_irq_chip_data *data);
 200 int regmap_irq_chip_get_base(struct regmap_irq_chip_data *data);
 201
 202 #endif