kernel/linux.git/include/linux/nvmem-consumer.h, branch v6.6.131

nvmem: core: add nvmem_dev_size() helper

2024-09-18T17:24:04+00:00

[ Upstream commit 33cf42e68efc8ff529a7eee08a4f0ba8c8d0a207 ] This is required by layouts that need to read whole NVMEM content. It's especially useful for NVMEM devices without hardcoded layout (like U-Boot environment data block). Signed-off-by: Rafał Miłecki Reviewed-by: Miquel Raynal Link: https://lore.kernel.org/r/20231221173421.13737-2-zajec5@gmail.com Signed-off-by: Greg Kroah-Hartman Stable-dep-of: 8679e8b4a1eb ("nvmem: u-boot-env: error if NVMEM device is too small") Signed-off-by: Sasha Levin

nvmem: core: Notify when a new layout is registered

2023-08-23T14:34:02+00:00

Tell listeners a new layout was introduced and is now available. Signed-off-by: Miquel Raynal Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230823132744.350618-23-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: Return NULL when no nvmem layout is found

2023-08-23T14:34:02+00:00

Currently, of_nvmem_layout_get_container() returns NULL on error, or an error pointer if either CONFIG_NVMEM or CONFIG_OF is turned off. We should likely avoid this kind of mix for two reasons: to clarify the intend and anyway fix the !CONFIG_OF which will likely always if we use this helper somewhere else. Let's just return NULL when no layout is found, we don't need an error value here. Link: https://staticthinking.wordpress.com/2022/08/01/mixing-error-pointers-and-null/ Fixes: 266570f496b9 ("nvmem: core: introduce NVMEM layouts") Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202308030002.DnSFOrMB-lkp@intel.com/ Signed-off-by: Miquel Raynal Reviewed-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230823132744.350618-21-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: introduce NVMEM layouts

2023-04-05T17:41:11+00:00

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 Signed-off-by: Miquel Raynal Signed-off-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230404172148.82422-14-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: move struct nvmem_cell_info to nvmem-provider.h

2023-02-06T18:06:59+00:00

struct nvmem_cell_info is used to describe a cell. Thus this should really be in the nvmem-provider's header. There are two (unused) nvmem access methods which use the nvmem_cell_info to describe the cell to be accesses. One can argue, that they will create a cell before accessing, thus they are both a provider and a consumer. struct nvmem_cell_info will get used more and more by nvmem-providers, don't force them to also include the consumer header, although they are not. Signed-off-by: Michael Walle Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20230206134356.839737-14-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: support passing DT node in cell info

2022-05-09T13:44:21+00:00

Some hardware may have NVMEM cells described in Device Tree using individual nodes. Let drivers pass such nodes to the NVMEM subsystem so they can be later used by NVMEM consumers. Signed-off-by: Rafał Miłecki Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20220429162701.2222-2-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: Add stubs for nvmem_cell_read_variable_le_u32/64 if !CONFIG_NVMEM

2021-09-14T07:02:50+00:00

When I added nvmem_cell_read_variable_le_u32() and nvmem_cell_read_variable_le_u64() I forgot to add the "static inline" stub functions for when CONFIG_NVMEM wasn't defined. Add them now. This was causing problems with randconfig builds that compiled `drivers/soc/qcom/cpr.c`. Fixes: 6feba6a62c57 ("PM: AVS: qcom-cpr: Use nvmem_cell_read_variable_le_u32()") Fixes: a28e824fb827 ("nvmem: core: Add functions to make number reading easy") Reported-by: kernel test robot Reviewed-by: Bjorn Andersson Signed-off-by: Douglas Anderson Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20210913160551.12907-1-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: Add functions to make number reading easy

2021-04-02T14:26:33+00:00

Sometimes the clients of nvmem just want to get a number out of nvmem. They don't want to think about exactly how many bytes the nvmem cell took up. They just want the number. Let's make it easy. In general this concept is useful because nvmem space is precious and usually the fewest bits are allocated that will hold a given value on a given system. However, even though small numbers might be fine on one system that doesn't mean that logically the number couldn't be bigger. Imagine nvmem containing a max frequency for a component. On one system perhaps that fits in 16 bits. On another system it might fit in 32 bits. The code reading this number doesn't care--it just wants the number. We'll provide two functions: nvmem_cell_read_variable_le_u32() and nvmem_cell_read_variable_le_u64(). Comparing these to the existing functions like nvmem_cell_read_u32(): * These new functions have no problems if the value was stored in nvmem in fewer bytes. It's OK to use these function as long as the value stored will fit in 32-bits (or 64-bits). * These functions avoid problems that the earlier APIs had with bit offsets. For instance, you can't use nvmem_cell_read_u32() to read a value has nbits=32 and bit_offset=4 because the nvmem cell must be at least 5 bytes big to hold this value. The new API accounts for this and works fine. * These functions make it very explicit that they assume that the number was stored in little endian format. The old functions made this assumption whenever bit_offset was non-zero (see nvmem_shift_read_buffer_in_place()) but didn't whenever the bit_offset was zero. NOTE: it's assumed that we don't need an 8-bit or 16-bit version of this function. The 32-bit version of the function can be used to read 8-bit or 16-bit data. At the moment, I'm only adding the "unsigned" versions of these functions, but if it ends up being useful someone could add a "signed" version that did 2's complement sign extension. At the moment, I'm only adding the "little endian" versions of these functions. Adding the "big endian" version would require adding "big endian" support to nvmem_shift_read_buffer_in_place(). Signed-off-by: Douglas Anderson Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20210330111241.19401-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: Add nvmem_cell_read_u8()

2020-07-29T15:12:08+00:00

Complement the u16, u32 and u64 helpers with a u8 variant to ease accessing byte-sized values. This helper will be useful for Realtek Digital Home Center platforms, which store some byte and sub-byte sized values in non-volatile memory. Signed-off-by: Andreas Färber Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20200722100705.7772-7-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman

nvmem: core: add nvmem_cell_read_u64

2020-03-19T06:41:02+00:00

Add nvmem_cell_read_u64() helper to ease read of an u64 value on consumer side. This helper is useful on some sunxi platform that has 64 bits data cells stored in no volatile memory. Signed-off-by: Yangtao Li Signed-off-by: Srinivas Kandagatla Link: https://lore.kernel.org/r/20200310132257.23358-4-srinivas.kandagatla@linaro.org Signed-off-by: Greg Kroah-Hartman