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

[Rafał Miłecki]

From: Rafał Miłecki <ra...@milecki.pl>

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 <ra...@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