nvmem: u-boot-env: post-process "ethaddr" env variable

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>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20230404172148.82422-36-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/nvmem/Kconfig b/drivers/nvmem/Kconfig
index a2afba11c8901d384eb638f022b6301b82e7c114..b291b27048c76f8d686c725665a545966d8deff3 100644 (file)
--- a/drivers/nvmem/Kconfig
+++ b/drivers/nvmem/Kconfig
@@ -340,6 +340,7 @@ config NVMEM_U_BOOT_ENV
        tristate "U-Boot environment variables support"
        depends on OF && MTD
        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/u-boot-env.c b/drivers/nvmem/u-boot-env.c
index 29b1d87a3c51554b53229160c4dc2db806747c89..ee9fd9989b6e2dbf8d0d56119eb69f4ef41a4cdd 100644 (file)
--- a/drivers/nvmem/u-boot-env.c
+++ b/drivers/nvmem/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/mtd/mtd.h>
@@ -70,6 +72,25 @@ static int u_boot_env_read(void *context, unsigned int offset, void *val,
        return 0;
 }
 
+static int u_boot_env_read_post_process_ethaddr(void *context, const char *id, int index,
+                                               unsigned int offset, void *buf, size_t bytes)
+{
+       u8 mac[ETH_ALEN];
+
+       if (bytes != 3 * ETH_ALEN - 1)
+               return -EINVAL;
+
+       if (!mac_pton(buf, mac))
+               return -EINVAL;
+
+       if (index)
+               eth_addr_add(mac, index);
+
+       ether_addr_copy(buf, mac);
+
+       return 0;
+}
+
 static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
                                size_t data_offset, size_t data_len)
 {
@@ -101,6 +122,11 @@ static int u_boot_env_add_cells(struct u_boot_env *priv, uint8_t *buf,
                priv->cells[idx].offset = data_offset + value - data;
                priv->cells[idx].bytes = strlen(value);
                priv->cells[idx].np = of_get_child_by_name(dev->of_node, priv->cells[idx].name);
+               if (!strcmp(var, "ethaddr")) {
+                       priv->cells[idx].raw_len = strlen(value);
+                       priv->cells[idx].bytes = ETH_ALEN;
+                       priv->cells[idx].read_post_process = u_boot_env_read_post_process_ethaddr;
+               }
        }
 
        if (WARN_ON(idx != priv->ncells))