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2024-09-11nvmem: layouts: add U-Boot env layoutRafał Miłecki1-0/+11
U-Boot environment variables are stored in a specific format. Actual data can be placed in various storage sources (MTD, UBI volume, EEPROM, NVRAM, etc.). Move all generic (NVMEM device independent) code from NVMEM device driver to an NVMEM layout driver. Then add a simple NVMEM layout code on top of it. This allows using NVMEM layout for parsing U-Boot env data stored in any kind of NVMEM device. The old NVMEM glue driver stays in place for handling bindings in the MTD context. To avoid code duplication it uses exported layout parsing function. Please note that handling MTD & NVMEM layout bindings may be refactored in the future. Signed-off-by: Rafał Miłecki <rafal@milecki.pl> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20240902142952.71639-5-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-15nvmem: core: Rework layouts to become regular devicesMiquel Raynal1-0/+8
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 <miquel.raynal@bootlin.com> Tested-by: Rafał Miłecki <rafal@milecki.pl> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20231215111536.316972-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05nvmem: layouts: onie-tlv: Add new layout driverMiquel Raynal1-0/+9
This layout applies on top of any non volatile storage device containing an ONIE table factory flashed. This table follows the tlv (type-length-value) organization described in the link below. We cannot afford using regular parsers because the content of these tables is manufacturer specific and must be dynamically discovered. Link: https://opencomputeproject.github.io/onie/design-spec/hw_requirements.html Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20230404172148.82422-24-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05nvmem: layouts: sl28vpd: Add new layout driverMichael Walle1-0/+9
This layout applies to the VPD of the Kontron sl28 boards. The VPD only contains a base MAC address. Therefore, we have to add an individual offset to it. This is done by taking the second argument of the nvmem phandle into account. Also this let us checking the VPD version and the checksum. Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20230404172148.82422-22-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05nvmem: core: introduce NVMEM layoutsMichael Walle1-0/+5
NVMEM layouts are used to generate NVMEM cells during runtime. Think of an EEPROM with a well-defined conent. For now, the content can be described by a device tree or a board file. But this only works if the offsets and lengths are static and don't change. One could also argue that putting the layout of the EEPROM in the device tree is the wrong place. Instead, the device tree should just have a specific compatible string. Right now there are two use cases: (1) The NVMEM cell needs special processing. E.g. if it only specifies a base MAC address offset and you need to add an offset, or it needs to parse a MAC from ASCII format or some proprietary format. (Post processing of cells is added in a later commit). (2) u-boot environment parsing. The cells don't have a particular offset but it needs parsing the content to determine the offsets and length. Co-developed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Michael Walle <michael@walle.cc> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Link: https://lore.kernel.org/r/20230404172148.82422-14-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>