kernel/linux.git/drivers/base/regmap/internal.h, branch v6.19.11

regcache: Add ->populate() callback to separate from ->init()

2025-10-31T12:01:51+00:00

In the future changes we would like to change the flow of the cache handling. Add ->populate() callback in order to prepare for that. Signed-off-by: Andy Shevchenko Reviewed-by: Charles Keepax Link: https://patch.msgid.link/20251031080540.3970776-2-andriy.shevchenko@linux.intel.com Signed-off-by: Mark Brown

regmap: add flat cache with sparse validity

2025-10-29T12:54:04+00:00

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

regmap: Reorder 'struct regmap'

2025-02-03T00:38:32+00:00

On a x86_64, with configured with allmodconfig, pahole states that the regmap structure is: /* size: 1048, cachelines: 17, members: 78 */ /* sum members: 1006, holes: 9, sum holes: 35 */ /* padding: 7 */ /* member types with holes: 2, total: 2 */ /* last cacheline: 24 bytes */ So, when such a struct is allocated, 2048 bytes are allocated, with most of this space being wasted. Move a few bools so that the size is reduced to 1024. After this change, pahole gives: /* size: 1024, cachelines: 16, members: 78 */ /* sum members: 1006, holes: 6, sum holes: 18 */ /* member types with holes: 2, total: 2 */ Signed-off-by: Christophe JAILLET Link: https://patch.msgid.link/f01f900d15633d5cda5f27763723acb307c0d22f.1737725820.git.christophe.jaillet@wanadoo.fr Signed-off-by: Mark Brown

regmap: maple: Provide lockdep (sub)class for maple tree's internal lock

2024-10-31T17:24:19+00:00

In some cases when using the maple tree register cache, the lockdep validator might complain about invalid deadlocks: [7.131886] Possible interrupt unsafe locking scenario: [7.131890] CPU0 CPU1 [7.131893] ---- ---- [7.131896] lock(&mt->ma_lock); [7.131904] local_irq_disable(); [7.131907] lock(rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock); [7.131916] lock(&mt->ma_lock); [7.131925] [7.131928] lock(rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock); [7.131936] *** DEADLOCK *** [7.131939] no locks held by swapper/0/0. [7.131944] the shortest dependencies between 2nd lock and 1st lock: [7.131950] -> (&mt->ma_lock){+.+.}-{2:2} { [7.131966] HARDIRQ-ON-W at: [7.131973] lock_acquire+0x200/0x330 [7.131986] _raw_spin_lock+0x50/0x70 [7.131998] regcache_maple_write+0x68/0xe0 [7.132010] regcache_write+0x6c/0x90 [7.132019] _regmap_read+0x19c/0x1d0 [7.132029] _regmap_update_bits+0xc0/0x148 [7.132038] regmap_update_bits_base+0x6c/0xa8 [7.132048] rk8xx_probe+0x22c/0x3d8 [7.132057] rk8xx_spi_probe+0x74/0x88 [7.132065] spi_probe+0xa8/0xe0 [...] [7.132675] } [7.132678] ... key at: [] __key.0+0x0/0x10 [7.132691] ... acquired at: [7.132695] _raw_spin_lock+0x50/0x70 [7.132704] regcache_maple_write+0x68/0xe0 [7.132714] regcache_write+0x6c/0x90 [7.132724] _regmap_read+0x19c/0x1d0 [7.132732] _regmap_update_bits+0xc0/0x148 [7.132741] regmap_field_update_bits_base+0x74/0xb8 [7.132751] vop2_plane_atomic_update+0x480/0x14d8 [rockchipdrm] [7.132820] drm_atomic_helper_commit_planes+0x1a0/0x320 [drm_kms_helper] [...] [7.135112] -> (rockchip_drm_vop2:3114:(&vop2_regmap_config)->lock){-...}-{2:2} { [7.135130] IN-HARDIRQ-W at: [7.135136] lock_acquire+0x200/0x330 [7.135147] _raw_spin_lock_irqsave+0x6c/0x98 [7.135157] regmap_lock_spinlock+0x20/0x40 [7.135166] regmap_read+0x44/0x90 [7.135175] vop2_isr+0x90/0x290 [rockchipdrm] [7.135225] __handle_irq_event_percpu+0x124/0x2d0 In the example above, the validator seems to get the scope of dependencies wrong, since the regmap instance used in rk8xx-spi driver has nothing to do with the instance from vop2. Improve validation by sharing the regmap's lockdep class with the maple tree's internal lock, while also providing a subclass for the latter. Signed-off-by: Cristian Ciocaltea Link: https://patch.msgid.link/20241031-regmap-maple-lockdep-fix-v2-1-06a3710f3623@collabora.com Signed-off-by: Mark Brown

regmap: kunit: Create a struct device for the regmap

2024-04-08T15:38:07+00:00

Use kunit_device_register() to create a real struct device for the regmap instead of leaving it at NULL. The main reason for this is that it allows context data to be passed into the readable_reg/writable_reg/volatile_reg functions by attaching it to the struct device with dev_set_drvdata(). The gen_regmap() and gen_raw_regmap() functions are updated to take a struct kunit * argument. A new struct regmap_test_priv has been created to hold the struct device created by kunit_device_register(). This allows the struct to be extended in the future to hold more private data for the test suite. Signed-off-by: Richard Fitzgerald Link: https://msgid.link/r/20240408144600.230848-3-rf@opensource.cirrus.com Signed-off-by: Mark Brown

regmap: rework ->max_register handling

2024-02-05T14:32:35+00:00

When regmap consists of single register, 'regmap' subsystem is unable to understand whether ->max_register is set or not, because in both cases it is equal to zero. It leads to that the logic based on value of ->max_register doesn't work. For example using of REGCACHE_FLAT fails. This patch introduces an extra parameter to regmap config, indicating that zero value in ->max_register is authentic. Signed-off-by: Jan Dakinevich Link: https://lore.kernel.org/r/20240126200836.1829995-1-jan.dakinevich@salutedevices.com Signed-off-by: Mark Brown

regmap: ram: support noinc semantics

2023-11-13T01:26:17+00:00

Support noinc semantics in RAM backed regmaps, for testing purposes. Add a new callback that selects registers which should have noinc behavior. Bulk writes to a noinc register will cause the last value in the buffer to be assigned to the register, while bulk reads will copy the same value repeatedly into the buffer. This patch only adds support to regmap-raw-ram, since regmap-ram does not support bulk operations. Signed-off-by: Ben Wolsieffer Link: https://lore.kernel.org/r/20231102203039.3069305-1-ben.wolsieffer@hefring.com Signed-off-by: Mark Brown

regmap: Add debugfs file for forcing field writes

2023-06-13T12:15:04+00:00

`_regmap_update_bits()` checks if the current register value differs from the new value, and only writes to the register if they differ. When testing hardware drivers, it might be desirable to always force a register write, for example when writing to a `regmap_field`. This enables and simplifies testing and verification of the hardware interaction. For example, when using a hardware mock/simulation model, one can then more easily verify that the driver makes the correct expected register writes during certain events. Add a bool variable `force_write_field` and a corresponding debugfs entry to enable this. Since this feature could interfere with driver operation, guard it with a macro. Signed-off-by: Waqar Hameed Link: https://lore.kernel.org/r/pnd1qifa7sj.fsf@axis.com Signed-off-by: Mark Brown

regmap: Provide basic test coverage for raw I/O

2023-06-12T17:14:53+00:00

Merge series from Mark Brown : Our existing coverage only deals with buses that provide single register read and write operations, extend it to cover raw buses using a similar approach with a RAM backed register map that the tests can inspect to check operations. This coverage could be more complete but provides a good start.

regmap: Don't check for changes in regcache_set_val()

2023-06-12T13:51:07+00:00

The only user of regcache_set_val() ignores the return value so we may as well not bother checking if the value we are trying to set is the same as the value already stored. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20230609-regcache-set-val-no-ret-v1-1-9a6932760cf8@kernel.org Signed-off-by: Mark Brown