ramips: ethernet: ralink: add led_source dts-binding

this adds the new dts-binding "mediatek,led_source"
currently for MT7628AN and MT7688 built-in switches,
which is documented as a 3-bit field configuring the
switch LEDs for various control schemes from 0 to 3.

Normally this is not needed, but e.g. for Asus RT-AC1200-V2
it is a must to set it to the anyway undocumented value
of 4, to have the switch LEDs react correctly on link/act
events. This is an MT7628DAN device, but I doubt this is
a speciality of this particular SoC.

Also added the RT305X_ESW_LED_OFF value to LED states.
Did also rename the register RT5350_EWS_REG_LED_POLARITY
to RT5350_EWS_REG_LED_CONTROL, which is the correct name.
Also making use of defines for some hardcoded values.

Signed-off-by: Tamas Balogh <tamasbalogh@hotmail.com>

target/linux/ramips/files/drivers/net/ethernet/ralink/esw_rt3050.c

@@ -79,6 +79,7 @@
 #define RT305X_ESW_LED_100MACT		8
 /* Additional led states not in datasheet: */
 #define RT305X_ESW_LED_BLINK		10
+#define RT305X_ESW_LED_OFF		11
 #define RT305X_ESW_LED_ON		12
 
 #define RT305X_ESW_LINK_S		25
@@ -174,7 +175,7 @@
 #define RT305X_ESW_NUM_LEDS		5
 
 #define RT5350_ESW_REG_PXTPC(_x)	(0x150 + (4 * _x))
-#define RT5350_EWS_REG_LED_POLARITY	0x168
+#define RT5350_EWS_REG_LED_CONTROL	0x168
 
 enum {
 	/* Global attributes. */
@@ -227,6 +228,7 @@ struct rt305x_esw {
 	unsigned int		reg_initval_fct2;
 	unsigned int		reg_initval_fpa2;
 	unsigned int		reg_led_polarity;
+	unsigned int		reg_led_source;
 
 	struct switch_dev	swdev;
 	bool			global_vlan_enable;
@@ -517,11 +519,11 @@ static void esw_hw_init(struct rt305x_esw *esw)
 	esw_w32(esw, 0x00000000, RT305X_ESW_REG_FPA);
 
 	/* Force Link/Activity on ports */
-	esw_w32(esw, 0x00000005, RT305X_ESW_REG_P0LED);
-	esw_w32(esw, 0x00000005, RT305X_ESW_REG_P1LED);
-	esw_w32(esw, 0x00000005, RT305X_ESW_REG_P2LED);
-	esw_w32(esw, 0x00000005, RT305X_ESW_REG_P3LED);
-	esw_w32(esw, 0x00000005, RT305X_ESW_REG_P4LED);
+	esw_w32(esw, RT305X_ESW_LED_LINKACT, RT305X_ESW_REG_P0LED);
+	esw_w32(esw, RT305X_ESW_LED_LINKACT, RT305X_ESW_REG_P1LED);
+	esw_w32(esw, RT305X_ESW_LED_LINKACT, RT305X_ESW_REG_P2LED);
+	esw_w32(esw, RT305X_ESW_LED_LINKACT, RT305X_ESW_REG_P3LED);
+	esw_w32(esw, RT305X_ESW_LED_LINKACT, RT305X_ESW_REG_P4LED);
 
 	/* Copy disabled port configuration from device tree setup */
 	port_disable = esw->port_disable;
@@ -589,7 +591,7 @@ static void esw_hw_init(struct rt305x_esw *esw)
 
 		/* set the led polarity */
 		esw_w32(esw, esw->reg_led_polarity & 0x1F,
-			RT5350_EWS_REG_LED_POLARITY);
+			RT5350_EWS_REG_LED_CONTROL);
 
 		/* local registers */
 		rt305x_mii_write(esw, 0, 31, 0x8000);
@@ -644,9 +646,10 @@ static void esw_hw_init(struct rt305x_esw *esw)
 
 		esw_reset_ephy(esw);
 
-		/* set the led polarity */
-		esw_w32(esw, esw->reg_led_polarity & 0x1F,
-			RT5350_EWS_REG_LED_POLARITY);
+		/* set the led polarity and led source */
+		esw_w32(esw, (esw->reg_led_polarity & 0x1F) |
+				((esw->reg_led_source << 8) & 0x700),
+				RT5350_EWS_REG_LED_CONTROL);
 
 		rt305x_mii_write(esw, 0, 31, 0x2000); /* change G2 page */
 		rt305x_mii_write(esw, 0, 26, 0x0020);
@@ -1435,6 +1438,10 @@ static int esw_probe(struct platform_device *pdev)
 	if (reg_init)
 		esw->reg_led_polarity = be32_to_cpu(*reg_init);
 
+	reg_init = of_get_property(np, "mediatek,led_source", NULL);
+	if (reg_init)
+		esw->reg_led_source = be32_to_cpu(*reg_init);
+
 	esw->rst_esw = devm_reset_control_get(&pdev->dev, "esw");
 	if (IS_ERR(esw->rst_esw))
 		esw->rst_esw = NULL;