On Fri, Mar 23, 2018 at 03:24:34PM +0100, Mike Looijmans wrote:
It's common practice to store MAC addresses for network interfaces into
nvmem devices. However the code to actually do this in the kernel lacks,
so this patch adds of_get_nvmem_mac_address() for drivers to obtain the
address from an nvmem cell provider.
This is particulary useful on devices where the ethernet interface cannot
be configured by the bootloader, for example because it's in an FPGA.
Tested by adapting the cadence macb driver to call this instead of
of_get_mac_address().
Hi Mike
Please can you document the device tree binding. I assume you are
adding a nvmen-cells and nvmem-cell-names to the Ethernet node in
device tree.
+/**
+ * Search the device tree for a MAC address, by calling of_get_mac_address
+ * and if that doesn't provide an address, fetch it from an nvmem provider
+ * using the name 'mac-address'.
+ * On success, copies the new address is into memory pointed to by addr and
+ * returns 0. Returns a negative error code otherwise.
+ * @dev: Pointer to the device containing the device_node
+ * @addr: Pointer to receive the MAC address using ether_addr_copy()
+ */
+int of_get_nvmem_mac_address(struct device *dev, char *addr)
+{
+ const char *mac;
+ struct nvmem_cell *cell;
+ size_t len;
+ int ret;
+
+ mac = of_get_mac_address(dev->of_node);
+ if (mac) {
+ ether_addr_copy(addr, mac);
+ return 0;
+ }
Is there a need to add a new API? Could of_get_mac_address() be
extended to look in NVMEM? The MAC driver does not care. It is saying,
using OF get me a MAC address. One API seems sufficient, and would
mean you don't need to change the MAC drivers.