kernel.git/drivers/base/regmap/regmap-mmio.c, branch linux-5.13.y

regmap: mmio: add config option to allow relaxed MMIO accesses

2020-10-26T19:54:59Z

On some platforms (eg armv7 due to the CONFIG_ARM_DMA_MEM_BUFFERABLE) MMIO R/W operations always add memory barriers which can increase load, decrease battery life or in general reduce performance unnecessarily on devices which access a lot of configuration registers and where ordering does not matter (eg. media accelerators like the Verisilicon / Hantro video decoders). Drivers used to call the relaxed MMIO variants directly but since they are now accessing the MMIO registers via regmaps (to compensate for different VPU HW reg layouts via regmap fields), there is a need for a relaxed API / config to preserve existing behaviour. Cc: Mark Brown Signed-off-by: Adrian Ratiu Link: https://lore.kernel.org/r/20201014203024.954369-1-adrian.ratiu@collabora.com Signed-off-by: Mark Brown

regmap: add proper SPDX identifiers on files that did not have them.

2019-04-25T19:22:15Z

There were a few files in the regmap code that did not have SPDX identifiers on them, so fix that up. At the same time, remove the "free form" text that specified the license of the file, as that is impossible for any tool to properly parse. Also, as Mark loves // comment markers, convert all of the headers to be the same to make things look consistent :) Signed-off-by: Greg Kroah-Hartman Signed-off-by: Mark Brown

regmap: Skip clk_put for attached clocks when freeing context

2018-05-17T07:11:41Z

Capability to attach an existing clk to a MMIO regmap was introduced in 4.17rc1. However, when using attached clk, regmap does not do the clk_get. Therefore it should not do the clk_put when freeing the MMIO regmap context. There does not appear to be any users of attached clocks yet so this would be a good time to make this change before anything depends on the existing behaviour. Signed-off-by: James Kelly Acked-by: Maxime Ripard Signed-off-by: Mark Brown

regmap: mmio: Add function to attach a clock

2018-02-26T11:05:44Z

regmap_init_mmio_clk allows to specify a clock that needs to be enabled while accessing the registers. However, that clock is retrieved through its clock ID, which means it will lookup that clock based on the current device that registers the regmap, and, in the DT case, will only look in that device OF node. This might be problematic if the clock to enable is stored in another node. Let's add a function that allows to attach a clock that has already been retrieved to a regmap in order to fix this. Signed-off-by: Maxime Ripard Signed-off-by: Mark Brown

Merge remote-tracking branches 'regmap/fix/be', 'regmap/fix/doc' and 'regmap/fix/spmi' into regmap-linus

2016-05-13T09:36:10Z

regmap: mmio: Explicitly say little endian is the defualt in the bus config

2016-03-31T20:41:12Z

Otherwise the DT parsing will default to big endian if nothing is specified. Reported-by: Krzysztof Kozlowski Signed-off-by: Mark Brown

regmap: mmio: Parse endianness definitions from DT

2016-03-30T15:46:15Z

Since we changed to do formatting in the bus we now skip all the format parsing that the core does for its data marshalling code. This means that we skip the DT parsing it does which breaks some systems, we need to add an explict call in the MMIO code to do this. Reported-by: Alexander Stein Tested-by: Alexander Stein Signed-off-by: Mark Brown

regmap: mmio: Fix value endianness selection

2016-03-23T13:41:06Z

Currently when selecting value endianness we check the register endiannes, not the value endianness. Reported-by: Alexander Stein Tested-by: Alexander Stein Signed-off-by: Mark Brown

regmap: mmio: Convert to regmap_bus and fix accessor usage

2016-01-27T20:04:50Z

Currently regmap-mmio uses the __raw accessors to read and write from memory. This is not safe as these interact poorly with spinlocks and are not guaranteed to generate emulated instructions on at least ARM where regmap is commonly used. The APIs that are provided all provide some byte swapping so this is difficult to do with the current regmap-mmio implementation which attempts to use the regmap core byte swapping. We can fix this by modernising the MMIO implementation to use reg_read() and reg_write() operations which were added after the API was implemented and pass simple unsigned integers through to the bus, making use of the formatting provided by the I/O accessors using a similar pattern to that used by the core. This will be less efficient for block I/O operations since we now enable and disable any required clocks per register but it is not clear that any users of regmap-mmio actually use block I/O and there is room to optimise later. This removes support for big endian I/O on 64 bit registers since no I/O accessors are provided, no current users were found and support can be added easily once they are available. In addition make the default endianness little endian. This was the behaviour prior to 29bb45f25ff305 (regmap-mmio: Use native endianness for read/write) and is the behaviour desired by most existing users, the users have been audited and those that need native endianness converted to request it explicitly. Previously native was documented as the default but due to the byte swapping in the accessors this was not correctly implemented. Fixes: 29bb45f25ff305 (regmap-mmio: Use native endianness for read/write) Reported-by: Johannes Berg Tested-by: Johannes Berg Signed-off-by: Mark Brown

regmap: mmio: Add regmap_mmio_get_min_stride

2015-12-08T17:05:50Z

Splite the minimal stride parsing into one signal function. Signed-off-by: Xiubo Li Signed-off-by: Mark Brown