p71924506
/
linux_old1
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity
linux_old1/include/linux/regmap.h

149 lines
4.9 KiB
C
Raw Normal View History

regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 01:59:58 +08:00
#ifndef __LINUX_REGMAP_H
#define __LINUX_REGMAP_H
/*
* Register map access API
*
* Copyright 2011 Wolfson Microelectronics plc
*
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/device.h>
#include <linux/list.h>
include: replace linux/module.h with "struct module" wherever possible The <linux/module.h> pretty much brings in the kitchen sink along with it, so it should be avoided wherever reasonably possible in terms of being included from other commonly used <linux/something.h> files, as it results in a measureable increase on compile times. The worst culprit was probably device.h since it is used everywhere. This file also had an implicit dependency/usage of mutex.h which was masked by module.h, and is also fixed here at the same time. There are over a dozen other headers that simply declare the struct instead of pulling in the whole file, so follow their lead and simply make it a few more. Most of the implicit dependencies on module.h being present by these headers pulling it in have been now weeded out, so we can finally make this change with hopefully minimal breakage. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-05-27 01:46:22 +08:00
struct module;
regmap: Add I2C bus support Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-21 02:02:29 +08:00
struct i2c_client;
regmap: Add SPI bus support Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 17:42:10 +08:00
struct spi_device;
regmap: Add I2C bus support Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-21 02:02:29 +08:00
regmap: Introduce caching support This patch introduces caching support for regmap. The regcache API has evolved essentially out of ASoC soc-cache so most of the actual caching types (except LZO) have been tested in the past. The purpose of regcache is to optimize in time and space the handling of register caches. Time optimization is achieved by not having to go over a slow bus like I2C to read the value of a register, instead it is cached locally in memory and can be retrieved faster. Regarding space optimization, some of the cache types are better at packing the caches, for e.g. the rbtree and the LZO caches. By doing this the sacrifice in time still wins over doing I2C transactions. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:00 +08:00
/* An enum of all the supported cache types */
enum regcache_type {
REGCACHE_NONE,
regmap: Add the indexed cache support This is the simplest form of a cache available in regcache. Any registers whose default value is 0 are ignored. If any of those registers are modified in the future, they will be placed in the cache on demand. The cache layout is essentially using the provided register defaults by the regcache core directly and does not re-map it to another representation. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:01 +08:00
REGCACHE_INDEXED,
regmap: Add the rbtree cache support This patch adds support for the rbtree cache compression type. Each rbnode manages a variable length block of registers. There can be no two nodes with overlapping blocks. Each block has a base register and a currently top register, all the other registers, if any, lie in between these two and in ascending order. The reasoning behind the construction of this rbtree is simple. In the snd_soc_rbtree_cache_init() function, we iterate over the register defaults provided by the regcache core. For each register value that is non-zero we insert it in the rbtree. In order to determine in which rbnode we need to add the register, we first look if there is another register already added that is adjacent to the one we are about to add. If that is the case we append it in that rbnode block, otherwise we create a new rbnode with a single register in its block and add it to the tree. There are various optimizations across the implementation to speed up lookups by caching the most recently used rbnode. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:02 +08:00
REGCACHE_RBTREE,
regmap: Add the LZO cache support This patch adds support for LZO compression when storing the register cache. For a typical device whose register map would normally occupy 25kB or 50kB by using the LZO compression technique, one can get down to ~5-7kB. There might be a performance penalty associated with each individual read/write due to decompressing/compressing the underlying cache, however that should not be noticeable. These memory benefits depend on whether the target architecture can get rid of the memory occupied by the original register defaults cache which is marked as __devinitconst. Nevertheless there will be some memory gain even if the target architecture can't get rid of the original register map, this should be around ~30-32kB instead of 50kB. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:03 +08:00
REGCACHE_LZO
regmap: Introduce caching support This patch introduces caching support for regmap. The regcache API has evolved essentially out of ASoC soc-cache so most of the actual caching types (except LZO) have been tested in the past. The purpose of regcache is to optimize in time and space the handling of register caches. Time optimization is achieved by not having to go over a slow bus like I2C to read the value of a register, instead it is cached locally in memory and can be retrieved faster. Regarding space optimization, some of the cache types are better at packing the caches, for e.g. the rbtree and the LZO caches. By doing this the sacrifice in time still wins over doing I2C transactions. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:00 +08:00
};
regmap: Allow drivers to specify register defaults It is useful for the register cache code to be able to specify the default values for the device registers. The major use is when restoring the register cache after suspend, knowing the register defaults allows us to skip registers that are at their default values when we resume which can be a substantial win on larger modern devices. For some devices (mostly older ones) the hardware does not support readback so the only way we can know the values is from code and so initializing the cache with default values makes it much easier for drivers work with read/modify/write updates. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-19 17:09:38 +08:00
/**
* Default value for a register. We use an array of structs rather
* than a simple array as many modern devices have very sparse
* register maps.
*
* @reg: Register address.
* @def: Register default value.
*/
struct reg_default {
unsigned int reg;
unsigned int def;
};
regmap: Add kerneldoc for struct regmap_config Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-21 05:28:58 +08:00
/**
* Configuration for the register map of a device.
*
* @reg_bits: Number of bits in a register address, mandatory.
* @val_bits: Number of bits in a register value, mandatory.
regmap: Allow devices to specify which registers are accessible This is currently unused but we need to know which registers exist and their properties in order to implement diagnostics like register map dumps and the cache features. We use callbacks partly because properties can vary at runtime (eg, through access locks on registers) and partly because big switch statements are a good compromise between readable code and small data size for providing information on big register maps. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-21 05:33:39 +08:00
*
regmap: Fix kerneldoc errors for regmap Field names didn't match between the documentation and the code. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-09 09:23:22 +08:00
* @writeable_reg: Optional callback returning true if the register
* can be written to.
* @readable_reg: Optional callback returning true if the register
* can be read from.
* @volatile_reg: Optional callback returning true if the register
* value can't be cached.
* @precious_reg: Optional callback returning true if the rgister
* should not be read outside of a call from the driver
* (eg, a clear on read interrupt status register).
regmap: Allow drivers to specify register defaults It is useful for the register cache code to be able to specify the default values for the device registers. The major use is when restoring the register cache after suspend, knowing the register defaults allows us to skip registers that are at their default values when we resume which can be a substantial win on larger modern devices. For some devices (mostly older ones) the hardware does not support readback so the only way we can know the values is from code and so initializing the cache with default values makes it much easier for drivers work with read/modify/write updates. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-19 17:09:38 +08:00
*
* @max_register: Optional, specifies the maximum valid register index.
* @reg_defaults: Power on reset values for registers (for use with
* register cache support).
* @num_reg_defaults: Number of elements in reg_defaults.
regmap: Add support for device specific write and read flag masks. Some buses like SPI have no standard notation of read or write operations. The general scheme here is to set or clear specific bits in the register address to indicate whether the operation is a read or write. We already support having a read flag mask per bus, but as there is no standard the bits which need to be set or cleared differ between devices and vendors, thus we need a mechanism to specify them per device. This patch adds two new entries to the regmap_config struct, read_flag_mask and write_flag_mask. These will be or'ed onto the top byte when doing a read or write operation. If both masks are empty the device will fallback to the regmap_bus masks. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-06 02:46:32 +08:00
*
* @read_flag_mask: Mask to be set in the top byte of the register when doing
* a read.
* @write_flag_mask: Mask to be set in the top byte of the register when doing
* a write. If both read_flag_mask and write_flag_mask are
* empty the regmap_bus default masks are used.
regmap: Introduce caching support This patch introduces caching support for regmap. The regcache API has evolved essentially out of ASoC soc-cache so most of the actual caching types (except LZO) have been tested in the past. The purpose of regcache is to optimize in time and space the handling of register caches. Time optimization is achieved by not having to go over a slow bus like I2C to read the value of a register, instead it is cached locally in memory and can be retrieved faster. Regarding space optimization, some of the cache types are better at packing the caches, for e.g. the rbtree and the LZO caches. By doing this the sacrifice in time still wins over doing I2C transactions. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:00 +08:00
*
* @cache_type: The actual cache type.
* @reg_defaults_raw: Power on reset values for registers (for use with
* register cache support).
* @num_reg_defaults_raw: Number of elements in reg_defaults_raw.
regmap: Add kerneldoc for struct regmap_config Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-21 05:28:58 +08:00
*/
regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 01:59:58 +08:00
struct regmap_config {
int reg_bits;
int val_bits;
regmap: Allow devices to specify which registers are accessible This is currently unused but we need to know which registers exist and their properties in order to implement diagnostics like register map dumps and the cache features. We use callbacks partly because properties can vary at runtime (eg, through access locks on registers) and partly because big switch statements are a good compromise between readable code and small data size for providing information on big register maps. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-07-21 05:33:39 +08:00
bool (*writeable_reg)(struct device *dev, unsigned int reg);
bool (*readable_reg)(struct device *dev, unsigned int reg);
bool (*volatile_reg)(struct device *dev, unsigned int reg);
regmap: Add precious registers to the driver interface 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>
2011-08-08 14:40:22 +08:00
bool (*precious_reg)(struct device *dev, unsigned int reg);
regmap: Allow drivers to specify register defaults It is useful for the register cache code to be able to specify the default values for the device registers. The major use is when restoring the register cache after suspend, knowing the register defaults allows us to skip registers that are at their default values when we resume which can be a substantial win on larger modern devices. For some devices (mostly older ones) the hardware does not support readback so the only way we can know the values is from code and so initializing the cache with default values makes it much easier for drivers work with read/modify/write updates. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-08-19 17:09:38 +08:00
unsigned int max_register;
struct reg_default *reg_defaults;
regmap: Introduce caching support This patch introduces caching support for regmap. The regcache API has evolved essentially out of ASoC soc-cache so most of the actual caching types (except LZO) have been tested in the past. The purpose of regcache is to optimize in time and space the handling of register caches. Time optimization is achieved by not having to go over a slow bus like I2C to read the value of a register, instead it is cached locally in memory and can be retrieved faster. Regarding space optimization, some of the cache types are better at packing the caches, for e.g. the rbtree and the LZO caches. By doing this the sacrifice in time still wins over doing I2C transactions. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Tested-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-19 21:34:00 +08:00
unsigned int num_reg_defaults;
enum regcache_type cache_type;
const void *reg_defaults_raw;
unsigned int num_reg_defaults_raw;
regmap: Add support for device specific write and read flag masks. Some buses like SPI have no standard notation of read or write operations. The general scheme here is to set or clear specific bits in the register address to indicate whether the operation is a read or write. We already support having a read flag mask per bus, but as there is no standard the bits which need to be set or cleared differ between devices and vendors, thus we need a mechanism to specify them per device. This patch adds two new entries to the regmap_config struct, read_flag_mask and write_flag_mask. These will be or'ed onto the top byte when doing a read or write operation. If both masks are empty the device will fallback to the regmap_bus masks. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-06 02:46:32 +08:00
u8 read_flag_mask;
u8 write_flag_mask;
regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 01:59:58 +08:00
};
typedef int (*regmap_hw_write)(struct device *dev, const void *data,
size_t count);
typedef int (*regmap_hw_gather_write)(struct device *dev,
const void *reg, size_t reg_len,
const void *val, size_t val_len);
typedef int (*regmap_hw_read)(struct device *dev,
const void *reg_buf, size_t reg_size,
void *val_buf, size_t val_size);
/**
* Description of a hardware bus for the register map infrastructure.
*
* @write: Write operation.
* @gather_write: Write operation with split register/value, return -ENOTSUPP
* if not implemented on a given device.
* @read: Read operation. Data is returned in the buffer used to transmit
* data.
* @read_flag_mask: Mask to be set in the top byte of the register when doing
* a read.
*/
struct regmap_bus {
regmap_hw_write write;
regmap_hw_gather_write gather_write;
regmap_hw_read read;
u8 read_flag_mask;
};
struct regmap *regmap_init(struct device *dev,
const struct regmap_bus *bus,
const struct regmap_config *config);
regmap: Add I2C bus support Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-06-21 02:02:29 +08:00
struct regmap *regmap_init_i2c(struct i2c_client *i2c,
const struct regmap_config *config);
regmap: Add SPI bus support Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 17:42:10 +08:00
struct regmap *regmap_init_spi(struct spi_device *dev,
const struct regmap_config *config);
regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 01:59:58 +08:00
void regmap_exit(struct regmap *map);
int regmap_write(struct regmap *map, unsigned int reg, unsigned int val);
int regmap_raw_write(struct regmap *map, unsigned int reg,
const void *val, size_t val_len);
int regmap_read(struct regmap *map, unsigned int reg, unsigned int *val);
int regmap_raw_read(struct regmap *map, unsigned int reg,
void *val, size_t val_len);
int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val,
size_t val_count);
int regmap_update_bits(struct regmap *map, unsigned int reg,
unsigned int mask, unsigned int val);
regmap: Prototype regcache_sync() Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-20 01:21:49 +08:00
int regcache_sync(struct regmap *map);
regmap: Allow drivers to control cache_only flag Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-20 01:22:14 +08:00
void regcache_cache_only(struct regmap *map, bool enable);
regmap: Implement regcache_cache_bypass helper function Ensure we've got a function so users can enable/disable the cache bypass option. Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-29 21:36:27 +08:00
void regcache_cache_bypass(struct regmap *map, bool enable);
regmap: Track if the register cache is dirty and suppress unneeded syncs Allow drivers to optimise out the register cache sync if they didn't need to do one. If the hardware is desynced from the register cache (by power loss for example) then the driver should call regcache_mark_dirty() to let the core know about this. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-10-26 16:34:22 +08:00
void regcache_mark_dirty(struct regmap *map);
regmap: Allow drivers to control cache_only flag Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-09-20 01:22:14 +08:00
regmap: Add generic non-memory mapped register access API There are many places in the tree where we implement register access for devices on non-memory mapped buses, especially I2C and SPI. Since hardware designers seem to have settled on a relatively consistent set of register interfaces this can be effectively factored out into shared code. There are a standard set of formats for marshalling data for exchange with the device, with the actual I/O mechanisms generally being simple byte streams. We create an abstraction for marshaling data into formats which can be sent on the control interfaces, and create a standard method for plugging in actual transport underneath that. This is mostly a refactoring and renaming of the bottom level of the existing code for sharing register I/O which we have in ASoC. A subsequent patch in this series converts ASoC to use this. The main difference in interface is that reads return values by writing to a location provided by a pointer rather than in the return value, ensuring we can use the full range of the type for register data. We also use unsigned types rather than ints for the same reason. As some of the devices can have very large register maps the existing ASoC code also contains infrastructure for managing register caches. This cache work will be moved over in a future stage to allow for separate review, the current patch only deals with the physical I/O. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Liam Girdwood <lrg@ti.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Wolfram Sang <w.sang@pengutronix.de> Acked-by: Grant Likely <grant.likely@secretlab.ca>
2011-05-12 01:59:58 +08:00
#endif