[PATCH 6/8] nvmem: transformations: ethernet address offset support
From: Michael Walle <hidden>
Date: 2021-12-28 14:26:31
Also in:
linux-arm-kernel, lkml, netdev
Subsystem:
nvmem framework, the rest · Maintainers:
Srinivas Kandagatla, Linus Torvalds
An nvmem cell might just contain a base MAC address. To generate a address of a specific interface, add a transformation to add an offset to this base address. Add a generic implementation and the first user of it, namely the sl28 vpd storage. Signed-off-by: Michael Walle <redacted> --- drivers/nvmem/transformations.c | 45 +++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+)
diff --git a/drivers/nvmem/transformations.c b/drivers/nvmem/transformations.c
index 61642a9feefb..15cd26da1f83 100644
--- a/drivers/nvmem/transformations.c
+++ b/drivers/nvmem/transformations.c@@ -12,7 +12,52 @@ struct nvmem_transformations { nvmem_cell_post_process_t pp; }; +/** + * nvmem_transform_mac_address_offset() - Add an offset to a mac address cell + * + * A simple transformation which treats the index argument as an offset and add + * it to a mac address. This is useful, if the nvmem cell stores a base + * ethernet address. + * + * @index: nvmem cell index + * @data: nvmem data + * @bytes: length of the data + * + * Return: 0 or negative error code on failure. + */ +static int nvmem_transform_mac_address_offset(int index, unsigned int offset, + void *data, size_t bytes) +{ + if (bytes != ETH_ALEN) + return -EINVAL; + + if (index < 0) + return -EINVAL; + + if (!is_valid_ether_addr(data)) + return -EINVAL; + + eth_addr_add(data, index); + + return 0; +} + +static int nvmem_kontron_sl28_vpd_pp(void *priv, const char *id, int index, + unsigned int offset, void *data, + size_t bytes) +{ + if (!id) + return 0; + + if (!strcmp(id, "mac-address")) + return nvmem_transform_mac_address_offset(index, offset, data, + bytes); + + return 0; +} + static const struct nvmem_transformations nvmem_transformations[] = { + { .compatible = "kontron,sl28-vpd", .pp = nvmem_kontron_sl28_vpd_pp }, {} };
--
2.30.2