kernel/linux.git/include/linux/nvmem-provider.h, branch v6.12.80

nvmem: layouts: store owner from modules with nvmem_layout_driver_register()

2024-05-03T05:26:38+00:00

Modules registering driver with nvmem_layout_driver_register() might forget to set .owner field. The field is used by some of other kernel parts for reference counting (try_module_get()), so it is expected that drivers will set it. Solve the problem by moving this task away from the drivers to the core code, just like we did for platform_driver in commit 9447057eaff8 ("platform_device: use a macro instead of platform_driver_register"). Signed-off-by: Krzysztof Kozlowski Reviewed-by: Michael Walle Reviewed-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20240430084921.33387-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: drop nvmem_layout_get_match_data()

2024-01-04T16:01:13+00:00

Thanks for layouts refactoring we now have "struct device" associated with layout. Also its OF pointer points directly to the "nvmem-layout" DT node. All it takes to get match data is a generic of_device_get_match_data(). Signed-off-by: Rafał Miłecki Reviewed-by: Miquel Raynal Reviewed-by: Michael Walle Link: https://lore.kernel.org/r/20231219120104.3422-2-zajec5@gmail.com Signed-off-by: Greg Kroah-Hartman

nvmem: layouts: refactor .add_cells() callback arguments

2024-01-04T16:01:13+00:00

Simply pass whole "struct nvmem_layout" instead of single variables. There is nothing in "struct nvmem_layout" that we have to hide from layout drivers. They also access it during .probe() and .remove(). Thanks to this change: 1. API gets more consistent All layouts drivers callbacks get the same argument 2. Layouts get correct device Before this change NVMEM core code was passing NVMEM device instead of layout device. That resulted in: * Confusing prints * Calling devm_*() helpers on wrong device * Helpers like of_device_get_match_data() dereferencing NULLs 3. It gets possible to get match data First of all nvmem_layout_get_match_data() requires passing "struct nvmem_layout" which .add_cells() callback didn't have before this. It doesn't matter much as it's rather useless now anyway (and will be dropped). What's more important however is that of_device_get_match_data() can be used now thanks to owning a proper device pointer. Signed-off-by: Rafał Miłecki Reviewed-by: Miquel Raynal Reviewed-by: Michael Walle Link: https://lore.kernel.org/r/20231219120104.3422-1-zajec5@gmail.com Signed-off-by: Greg Kroah-Hartman

nvmem: core: Rework layouts to become regular devices

2023-12-15T12:30:07+00:00

Current layout support was initially written without modules support in mind. When the requirement for module support rose, the existing base was improved to adopt modularization support, but kind of a design flaw was introduced. With the existing implementation, when a storage device registers into NVMEM, the core tries to hook a layout (if any) and populates its cells immediately. This means, if the hardware description expects a layout to be hooked up, but no driver was provided for that, the storage medium will fail to probe and try later from scratch. Even if we consider that the hardware description shall be correct, we could still probe the storage device (especially if it contains the rootfs). One way to overcome this situation is to consider the layouts as devices, and leverage the native notifier mechanism. When a new NVMEM device is registered, we can populate its nvmem-layout child, if any, and wait for the matching to be done in order to get the cells (the waiting can be easily done with the NVMEM notifiers). If the layout driver is compiled as a module, it should automatically be loaded. This way, there is no strong order to enforce, any NVMEM device creation or NVMEM layout driver insertion will be observed as a new event which may lead to the creation of additional cells, without disturbing the probes with costly (and sometimes endless) deferrals. In order to achieve that goal we create a new bus for the nvmem-layouts with minimal logic to match nvmem-layout devices with nvmem-layout drivers. All this infrastructure code is created in the layouts.c file. Signed-off-by: Miquel Raynal Tested-by: Rafał Miłecki Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231215111536.316972-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: Move and rename ->fixup_cell_info()

2023-12-15T12:30:07+00:00

This hook is meant to be used by any provider and instantiating a layout just for this is useless. Let's instead move this hook to the nvmem device and add it to the config structure to be easily shared by the providers. While at moving this hook, rename it ->fixup_dt_cell_info() to clarify its main intended purpose. Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231215111536.316972-6-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: Simplify the ->add_cells() hook

2023-12-15T12:30:07+00:00

The layout entry is not used and will anyway be made useless by the new layout bus infrastructure coming next, so drop it. While at it, clarify the kdoc entry. Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231215111536.316972-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: Move of_nvmem_layout_get_container() in another header

2023-12-15T12:30:07+00:00

nvmem-consumer.h is included by consumer devices, extracting data from NVMEM devices whereas nvmem-provider.h is included by devices providing NVMEM content. The only users of of_nvmem_layout_get_container() outside of the core are layout drivers, so better move its prototype to nvmem-provider.h. While we do so, we also move the kdoc associated with the function to the header rather than the .c file. Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231215111536.316972-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

Revert "nvmem: add new config option"

2023-10-27T11:17:54+00:00

This reverts commit 517f14d9cf3533d5ab4fded195ab6f80a92e378f. Config option "no_of_node" is no longer needed since adding a more explicit and targeted option "add_legacy_fixed_of_cells". That "no_of_node" config option was needed *earlier* to help mtd's case. DT nodes of MTD partitions (that are also NVMEM devices) may contain subnodes. Those SHOULD NOT be treated as NVMEM fixed cells. To prevent NVMEM core code from parsing subnodes a "no_of_node" option was added (and set to true in mtd) to make for_each_child_of_node() in NVMEM a no-op. That was a bit hacky because it was messing with "of_node" pointer to achieve some side-effect. With the introduction of "add_legacy_fixed_of_cells" config option things got more explicit. MTD subsystem simply tells NVMEM when to look for fixed cells and there is no need to hack "of_node" pointer anymore. Signed-off-by: Rafał Miłecki Reviewed-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231023102759.31529-1-zajec5@gmail.com Signed-off-by: Greg Kroah-Hartman

nvmem: add explicit config option to read old syntax fixed OF cells

2023-10-21T17:19:06+00:00

Binding for fixed NVMEM cells defined directly as NVMEM device subnodes has been deprecated. It has been replaced by the "fixed-layout" NVMEM layout binding. New syntax is meant to be clearer and should help avoiding imprecise bindings. NVMEM subsystem already supports the new binding. It should be a good idea to limit support for old syntax to existing drivers that actually support & use it (we can't break backward compatibility!). That way we additionally encourage new bindings & drivers to ignore deprecated binding. It wasn't clear (to me) if rtc and w1 code actually uses old syntax fixed cells. I enabled them to don't risk any breakage. Signed-off-by: Rafał Miłecki [for meson-{efuse,mx-efuse}.c] Acked-by: Martin Blumenstingl [for mtk-efuse.c, nvmem/core.c, nvmem-provider.h] Reviewed-by: AngeloGioacchino Del Regno [MT8192, MT8195 Chromebooks] Tested-by: AngeloGioacchino Del Regno [for microchip-otpc.c] Reviewed-by: Claudiu Beznea [SAMA7G5-EK] Tested-by: Claudiu Beznea Acked-by: Jernej Skrabec Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20231020105545.216052-3-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: Add macro to register nvmem layout drivers

2023-04-05T17:41:13+00:00

Provide a module_nvmem_layout_driver() macro at the end of the nvmem-provider.h header to reduce the boilerplate when registering nvmem layout drivers. Suggested-by: Srinivas Kandagatla Signed-off-by: Miquel Raynal Acked-by: Rafał Miłecki Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-37-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman