Some devices are sensitive to reads on their registers, especially for things like clear on read interrupt status registers. Avoid creating problems with these with things like debugfs by allowing drivers to tell the core about them. If a register is marked as precious then the core will not internally generate any reads of it. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
106 lines
3.7 KiB
C
106 lines
3.7 KiB
C
#ifndef __LINUX_REGMAP_H
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#define __LINUX_REGMAP_H
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/*
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* Register map access API
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*
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* Copyright 2011 Wolfson Microelectronics plc
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*
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/device.h>
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#include <linux/list.h>
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#include <linux/module.h>
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struct i2c_client;
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struct spi_device;
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/**
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* Configuration for the register map of a device.
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*
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* @reg_bits: Number of bits in a register address, mandatory.
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* @val_bits: Number of bits in a register value, mandatory.
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*
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* @max_register: Optional, specifies the maximum valid register index.
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* @writeable_register: Optional callback returning true if the register
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* can be written to.
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* @readable_register: Optional callback returning true if the register
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* can be read from.
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* @volatile_register: Optional callback returning true if the register
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* value can't be cached.
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* @precious_register: Optional callback returning true if the rgister
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* should not be read outside of a call from the driver
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* (eg, a clear on read interrupt status register).
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*/
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struct regmap_config {
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int reg_bits;
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int val_bits;
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unsigned int max_register;
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bool (*writeable_reg)(struct device *dev, unsigned int reg);
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bool (*readable_reg)(struct device *dev, unsigned int reg);
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bool (*volatile_reg)(struct device *dev, unsigned int reg);
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bool (*precious_reg)(struct device *dev, unsigned int reg);
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};
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typedef int (*regmap_hw_write)(struct device *dev, const void *data,
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size_t count);
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typedef int (*regmap_hw_gather_write)(struct device *dev,
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const void *reg, size_t reg_len,
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const void *val, size_t val_len);
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typedef int (*regmap_hw_read)(struct device *dev,
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const void *reg_buf, size_t reg_size,
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void *val_buf, size_t val_size);
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/**
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* Description of a hardware bus for the register map infrastructure.
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*
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* @list: Internal use.
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* @type: Bus type, used to identify bus to be used for a device.
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* @write: Write operation.
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* @gather_write: Write operation with split register/value, return -ENOTSUPP
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* if not implemented on a given device.
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* @read: Read operation. Data is returned in the buffer used to transmit
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* data.
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* @owner: Module with the bus implementation, used to pin the implementation
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* in memory.
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* @read_flag_mask: Mask to be set in the top byte of the register when doing
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* a read.
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*/
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struct regmap_bus {
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struct list_head list;
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struct bus_type *type;
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regmap_hw_write write;
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regmap_hw_gather_write gather_write;
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regmap_hw_read read;
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struct module *owner;
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u8 read_flag_mask;
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};
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struct regmap *regmap_init(struct device *dev,
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const struct regmap_bus *bus,
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const struct regmap_config *config);
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struct regmap *regmap_init_i2c(struct i2c_client *i2c,
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const struct regmap_config *config);
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struct regmap *regmap_init_spi(struct spi_device *dev,
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const struct regmap_config *config);
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void regmap_exit(struct regmap *map);
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int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
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int regmap_raw_write(struct regmap *map, unsigned int reg,
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const void *val, size_t val_len);
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int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
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int regmap_raw_read(struct regmap *map, unsigned int reg,
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void *val, size_t val_len);
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int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
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size_t val_count);
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int regmap_update_bits(struct regmap *map, unsigned int reg,
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unsigned int mask, unsigned int val);
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#endif
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