[PATCH V3 6/6] nvmem: u-boot-env: post process "ethaddr" env variable

Rafał Miłecki
2023-01-27T12:57:52Z

U-Boot environment variables are stored in ASCII format so "ethaddr"
requires parsing into binary to make it work with Ethernet interfaces.

This includes support for indexes to support #nvmem-cell-cells = <1>.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
---
drivers/nvmem/layouts/Kconfig | 1 +
drivers/nvmem/layouts/u-boot-env.c | 25 +++++++++++++++++++++++++
2 files changed, 26 insertions(+)

diff --git a/drivers/nvmem/layouts/Kconfig b/drivers/nvmem/layouts/Kconfig
index 8a38c514943a..566b4f25630d 100644
--- a/drivers/nvmem/layouts/Kconfig
+++ b/drivers/nvmem/layouts/Kconfig
@@ -23,6 +23,7 @@ config NVMEM_LAYOUT_ONIE_TLV
config NVMEM_LAYOUT_U_BOOT_ENV
bool "U-Boot environment variables support"
select CRC32
+ select GENERIC_NET_UTILS
help
U-Boot stores its setup as environment variables. This driver adds
support for verifying & exporting such data. It also exposes variables
diff --git a/drivers/nvmem/layouts/u-boot-env.c b/drivers/nvmem/layouts/u-boot-env.c
index 95c314553952..e99b853a44c4 100644
--- a/drivers/nvmem/layouts/u-boot-env.c
+++ b/drivers/nvmem/layouts/u-boot-env.c
@@ -4,6 +4,8 @@
*/

#include <linux/crc32.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/nvmem-consumer.h>
@@ -36,6 +38,27 @@ struct u_boot_env_image_broadcom {
uint8_t data[];
} __packed;

+static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
+ unsigned int offset, void **data, size_t *bytes)
+{
+ u8 mac[ETH_ALEN];
+
+ if (*bytes != 3 * ETH_ALEN - 1)
+ return -EINVAL;
+
+ if (!mac_pton(*data, mac))
+ return -EINVAL;
+
+ if (index)
+ eth_addr_add(mac, index);
+
+ /* We need *smaller* buffer so don't bother to krealloc() */
+ ether_addr_copy(*data, mac);
+ *bytes = ETH_ALEN;
+
+ return 0;
+}
+
static int u_boot_env_parse_data(struct device *dev, struct nvmem_device *nvmem, uint8_t *buf,
size_t data_offset, size_t data_len)
{
@@ -67,6 +90,8 @@ static int u_boot_env_parse_data(struct device *dev, struct nvmem_device *nvmem,
info.offset = data_offset + value - data;
info.bytes = strlen(value);
info.np = of_get_child_by_name(np, info.name);
+ if (!strcmp(var, "ethaddr"))
+ info.read_post_process = u_boot_env_read_post_process_ethaddr;

err = nvmem_add_one_cell(nvmem, &info);
if (err) {
--
2.34.1