mac80211: rt2x00: load the eeprom data from devicetree embedded data on Ralink SoCs

It will allow loading eeprom from eeprom-data embedded in device tree.
Ported from mediatek mt76 wireless driver (drivers/net/wireless/mediatek/mt76/eeprom.c)

Signed-off-by: Coia Prant <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/17472
Signed-off-by: Hauke Mehrtens <[email protected]>

package/kernel/mac80211/patches/rt2x00/603-wifi-rt2x00-Add-support-for-loading-EEPROM-from-devicetree-embedded-data.patch

@@ -0,0 +1,76 @@
+From adf957124a115bdf3e4728e1ea8c70a632648cf0 Mon Sep 17 00:00:00 2001
+From: Coia Prant <[email protected]>
+Date: Fri, 14 Feb 2025 15:49:55 +0800
+Subject: [PATCH] wifi: rt2x00: Add support for loading EEPROM from devicetree
+ embedded data
+
+This patch allows rt2x00 to load eeprom from devicetree embedded data.
+
+Example:
+
+/* load eeprom from embedded data 'eeprom-data' */
+&wmac {
+	ralink,eeprom-data = <0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff
+			      0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff 0xffffffff>;
+};
+
+Signed-off-by: Coia Prant <[email protected]>
+---
+ .../net/wireless/ralink/rt2x00/rt2x00eeprom.c | 25 +++++++++++++++++++
+ 1 file changed, 25 insertions(+)
+
+--- a/drivers/net/wireless/ralink/rt2x00/rt2x00eeprom.c
++++ b/drivers/net/wireless/ralink/rt2x00/rt2x00eeprom.c
+@@ -33,6 +33,27 @@ static void rt2800lib_eeprom_swap(struct
+ 		rt2x00dev->eeprom[i] = swab16(rt2x00dev->eeprom[i]);
+ }
+ 
++static int rt2800lib_read_eeprom_data(struct rt2x00_dev *rt2x00dev)
++{
++	struct device_node *np = rt2x00dev->dev->of_node;
++	unsigned int len = rt2x00dev->ops->eeprom_size;
++	const void *data;
++	int size;
++
++	data = of_get_property(np, "ralink,eeprom-data", &size);
++	if (!data)
++		return -ENOENT;
++
++	if (size != len) {
++		dev_err(rt2x00dev->dev, "invalid eeprom size, required: 0x%04x\n", len);
++		return -EINVAL;
++	}
++
++	memcpy(rt2x00dev->eeprom, data, size);
++
++	return 0;
++}
++
+ #if IS_ENABLED(CONFIG_MTD)
+ static int rt2800lib_read_eeprom_mtd(struct rt2x00_dev *rt2x00dev)
+ {
+@@ -193,6 +214,10 @@ int rt2x00lib_read_eeprom(struct rt2x00_
+ {
+ 	int ret;
+ 
++	ret = rt2800lib_read_eeprom_data(rt2x00dev);
++	if (!ret)
++		return 0;
++
+ #if IS_ENABLED(CONFIG_MTD)
+ 	ret = rt2800lib_read_eeprom_mtd(rt2x00dev);
+ 	if (!ret)