From 013a3a66f25af3fb614f45df43983657514944c4 Mon Sep 17 00:00:00 2001 From: Charles Keepax Date: Mon, 20 Oct 2025 16:54:55 +0100 Subject: regmap: sdw-mbq: Don't assume the regmap device is the SoundWire slave Currently, the code assumes that the device that registered the MBQ register map is the actual SoundWire slave device. This works fine for all current users, however future SDCA devices will likely be implemented with the SoundWire slave as a parent device and separate child drivers with regmaps for each audio Function. Update the regmap_init_sdw_mbq_cfg macro to allow these two to be specified separately. Reviewed-by: Bard Liao Signed-off-by: Charles Keepax Reviewed-by: Pierre-Louis Bossart Link: https://patch.msgid.link/20251020155512.353774-3-ckeepax@opensource.cirrus.com Signed-off-by: Mark Brown --- include/linux/regmap.h | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'include/linux/regmap.h') diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4e1ac1fbcec4..70daec535976 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -676,7 +676,7 @@ struct regmap *__regmap_init_sdw(struct sdw_slave *sdw, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); -struct regmap *__regmap_init_sdw_mbq(struct sdw_slave *sdw, +struct regmap *__regmap_init_sdw_mbq(struct device *dev, struct sdw_slave *sdw, const struct regmap_config *config, const struct regmap_sdw_mbq_cfg *mbq_config, struct lock_class_key *lock_key, @@ -738,7 +738,7 @@ struct regmap *__devm_regmap_init_sdw(struct sdw_slave *sdw, const struct regmap_config *config, struct lock_class_key *lock_key, const char *lock_name); -struct regmap *__devm_regmap_init_sdw_mbq(struct sdw_slave *sdw, +struct regmap *__devm_regmap_init_sdw_mbq(struct device *dev, struct sdw_slave *sdw, const struct regmap_config *config, const struct regmap_sdw_mbq_cfg *mbq_config, struct lock_class_key *lock_key, @@ -970,7 +970,7 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); */ #define regmap_init_sdw_mbq(sdw, config) \ __regmap_lockdep_wrapper(__regmap_init_sdw_mbq, #config, \ - sdw, config, NULL) + &sdw->dev, sdw, config, NULL) /** * regmap_init_sdw_mbq_cfg() - Initialise MBQ SDW register map with config @@ -983,9 +983,9 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); * to a struct regmap. The regmap will be automatically freed by the * device management code. */ -#define regmap_init_sdw_mbq_cfg(sdw, config, mbq_config) \ +#define regmap_init_sdw_mbq_cfg(dev, sdw, config, mbq_config) \ __regmap_lockdep_wrapper(__regmap_init_sdw_mbq, #config, \ - sdw, config, mbq_config) + dev, sdw, config, mbq_config) /** * regmap_init_spi_avmm() - Initialize register map for Intel SPI Slave @@ -1198,12 +1198,13 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); */ #define devm_regmap_init_sdw_mbq(sdw, config) \ __regmap_lockdep_wrapper(__devm_regmap_init_sdw_mbq, #config, \ - sdw, config, NULL) + &sdw->dev, sdw, config, NULL) /** * devm_regmap_init_sdw_mbq_cfg() - Initialise managed MBQ SDW register map with config * - * @sdw: Device that will be interacted with + * @dev: Device that will be interacted with + * @sdw: SoundWire Device that will be interacted with * @config: Configuration for register map * @mbq_config: Properties for the MBQ registers * @@ -1211,9 +1212,9 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg); * to a struct regmap. The regmap will be automatically freed by the * device management code. */ -#define devm_regmap_init_sdw_mbq_cfg(sdw, config, mbq_config) \ - __regmap_lockdep_wrapper(__devm_regmap_init_sdw_mbq, \ - #config, sdw, config, mbq_config) +#define devm_regmap_init_sdw_mbq_cfg(dev, sdw, config, mbq_config) \ + __regmap_lockdep_wrapper(__devm_regmap_init_sdw_mbq, \ + #config, dev, sdw, config, mbq_config) /** * devm_regmap_init_slimbus() - Initialise managed register map -- cgit v1.2.3 From 9c7f7262bc1affb9b9acd2ec2fb1f6314d5d474c Mon Sep 17 00:00:00 2001 From: Sander Vanheule Date: Wed, 29 Oct 2025 09:12:47 +0100 Subject: regmap: add flat cache with sparse validity The flat regcache will always assume the data in the cache is valid. Since the cache is preferred over hardware access, this may shadow the actual state of the device. Add a new containing cache structure with the flat data table and a bitmap indicating cache validity. REGCACHE_FLAT will still behave as before, as the validity is ignored. Define new cache type REGCACHE_FLAT_S: a flat cache with sparse validity. The sparse validity is used to determine if a hardware access should occur to initialize the cache on the fly, vs. at regmap init for REGCACHE_FLAT. Contrary to REGCACHE_FLAT, this allows us to implement regcache_ops.drop. Signed-off-by: Sander Vanheule Link: https://patch.msgid.link/20251029081248.52607-2-sander@svanheule.net Signed-off-by: Mark Brown --- include/linux/regmap.h | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) (limited to 'include/linux/regmap.h') diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 4e1ac1fbcec4..17bed25dc4e3 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -55,18 +55,23 @@ struct sdw_slave; #define REGMAP_DOWNSHIFT(s) (s) /* - * The supported cache types, the default is no cache. Any new caches - * should usually use the maple tree cache unless they specifically - * require that there are never any allocations at runtime and can't - * provide defaults in which case they should use the flat cache. The - * rbtree cache *may* have some performance advantage for very low end - * systems that make heavy use of cache syncs but is mainly legacy. + * The supported cache types, the default is no cache. Any new caches should + * usually use the maple tree cache unless they specifically require that there + * are never any allocations at runtime in which case they should use the sparse + * flat cache. The rbtree cache *may* have some performance advantage for very + * low end systems that make heavy use of cache syncs but is mainly legacy. + * These caches are sparse and entries will be initialized from hardware if no + * default has been provided. + * The non-sparse flat cache is provided for compatibility with existing users + * and will zero-initialize cache entries for which no defaults are provided. + * New users should use the sparse flat cache. */ enum regcache_type { REGCACHE_NONE, REGCACHE_RBTREE, REGCACHE_FLAT, REGCACHE_MAPLE, + REGCACHE_FLAT_S, }; /** -- cgit v1.2.3 From dc65b1ed4bb34ab6235ff2cc6a917b9295c04c2c Mon Sep 17 00:00:00 2001 From: Sheetal Date: Fri, 23 Jan 2026 15:23:44 +0530 Subject: regmap: Add reg_default_cb callback for flat cache defaults Commit e062bdfdd6ad ("regmap: warn users about uninitialized flat cache") warns when REGCACHE_FLAT is used without full defaults. This causes false positives on hardware where many registers reset to zero but are not listed in reg_defaults, forcing drivers to maintain large tables just to silence the warning. Add a reg_default_cb() hook so drivers can supply defaults for registers not present in reg_defaults when populating REGCACHE_FLAT. This keeps the warning quiet for known zero-reset registers without bloating tables. Provide a generic regmap_default_zero_cb() helper for drivers that need zero defaults. The hook is only used for REGCACHE_FLAT; the core does not check readable/writeable access, so drivers must provide readable_reg/ writeable_reg callbacks and handle holes in the register map. Signed-off-by: Sheetal Link: https://patch.msgid.link/20260123095346.1258556-3-sheetal@nvidia.com Signed-off-by: Mark Brown --- include/linux/regmap.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/linux/regmap.h') diff --git a/include/linux/regmap.h b/include/linux/regmap.h index b0b9be750d93..caff2240bdab 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -359,6 +359,10 @@ typedef void (*regmap_unlock)(void *); * @reg_defaults: Power on reset values for registers (for use with * register cache support). * @num_reg_defaults: Number of elements in reg_defaults. + * @reg_default_cb: Optional callback to return default values for registers + * not listed in reg_defaults. This is only used for + * REGCACHE_FLAT population; drivers must ensure the readable_reg/ + * writeable_reg callbacks are defined to handle holes. * * @read_flag_mask: Mask to be set in the top bytes of the register when doing * a read. @@ -449,6 +453,8 @@ struct regmap_config { const struct regmap_access_table *rd_noinc_table; const struct reg_default *reg_defaults; unsigned int num_reg_defaults; + int (*reg_default_cb)(struct device *dev, unsigned int reg, + unsigned int *def); enum regcache_type cache_type; const void *reg_defaults_raw; unsigned int num_reg_defaults_raw; @@ -1349,6 +1355,14 @@ static inline int regmap_write_bits(struct regmap *map, unsigned int reg, return regmap_update_bits_base(map, reg, mask, val, NULL, false, true); } +static inline int regmap_default_zero_cb(struct device *dev, + unsigned int reg, + unsigned int *def) +{ + *def = 0; + return 0; +} + int regmap_get_val_bytes(struct regmap *map); int regmap_get_max_register(struct regmap *map); int regmap_get_reg_stride(struct regmap *map); -- cgit v1.2.3