net: dsa: realtek: add LED drivers for rtl8366rb

This commit introduces LED drivers for rtl8366rb, enabling LEDs to be
described in the device tree using the same format as qca8k. Each port
can configure up to 4 LEDs.

If all LEDs in a group use the default state "keep", they will use the
default behavior after a reset. Changing the brightness of one LED,
either manually or by a trigger, will disable the default hardware
trigger and switch the entire LED group to manually controlled LEDs.
Once in this mode, there is no way to revert to hardware-controlled LEDs
(except by resetting the switch).

Software triggers function as expected with manually controlled LEDs.
Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/realtek/rtl8366rb.c

@@ -176,6 +176,7 @@
 #define RTL8366RB_VLAN_INGRESS_CTRL2_REG	0x037f
 
 /* LED control registers */
+/* The LED blink rate is global; it is used by all triggers in all groups. */
 #define RTL8366RB_LED_BLINKRATE_REG		0x0430
 #define RTL8366RB_LED_BLINKRATE_MASK		0x0007
 #define RTL8366RB_LED_BLINKRATE_28MS		0x0000
@@ -191,31 +192,21 @@
 	(4 * (led_group))
 #define RTL8366RB_LED_CTRL_MASK(led_group)	\
 	(0xf << RTL8366RB_LED_CTRL_OFFSET(led_group))
-#define RTL8366RB_LED_OFF			0x0
-#define RTL8366RB_LED_DUP_COL			0x1
-#define RTL8366RB_LED_LINK_ACT			0x2
-#define RTL8366RB_LED_SPD1000			0x3
-#define RTL8366RB_LED_SPD100			0x4
-#define RTL8366RB_LED_SPD10			0x5
-#define RTL8366RB_LED_SPD1000_ACT		0x6
-#define RTL8366RB_LED_SPD100_ACT		0x7
-#define RTL8366RB_LED_SPD10_ACT			0x8
-#define RTL8366RB_LED_SPD100_10_ACT		0x9
-#define RTL8366RB_LED_FIBER			0xa
-#define RTL8366RB_LED_AN_FAULT			0xb
-#define RTL8366RB_LED_LINK_RX			0xc
-#define RTL8366RB_LED_LINK_TX			0xd
-#define RTL8366RB_LED_MASTER			0xe
-#define RTL8366RB_LED_FORCE			0xf
 
 /* The RTL8366RB_LED_X_X registers are used to manually set the LED state only
  * when the corresponding LED group in RTL8366RB_LED_CTRL_REG is
- * RTL8366RB_LED_FORCE. Otherwise, it is ignored.
+ * RTL8366RB_LEDGROUP_FORCE. Otherwise, it is ignored.
  */
 #define RTL8366RB_LED_0_1_CTRL_REG		0x0432
-#define RTL8366RB_LED_1_OFFSET			6
 #define RTL8366RB_LED_2_3_CTRL_REG		0x0433
-#define RTL8366RB_LED_3_OFFSET			6
+#define RTL8366RB_LED_X_X_CTRL_REG(led_group)	\
+	((led_group) <= 1 ? \
+		RTL8366RB_LED_0_1_CTRL_REG : \
+		RTL8366RB_LED_2_3_CTRL_REG)
+#define RTL8366RB_LED_0_X_CTRL_MASK		GENMASK(5, 0)
+#define RTL8366RB_LED_X_1_CTRL_MASK		GENMASK(11, 6)
+#define RTL8366RB_LED_2_X_CTRL_MASK		GENMASK(5, 0)
+#define RTL8366RB_LED_X_3_CTRL_MASK		GENMASK(11, 6)
 
 #define RTL8366RB_MIB_COUNT			33
 #define RTL8366RB_GLOBAL_MIB_COUNT		1
@@ -359,14 +350,44 @@
 #define RTL8366RB_GREEN_FEATURE_TX	BIT(0)
 #define RTL8366RB_GREEN_FEATURE_RX	BIT(2)
 
+enum rtl8366_ledgroup_mode {
+	RTL8366RB_LEDGROUP_OFF			= 0x0,
+	RTL8366RB_LEDGROUP_DUP_COL		= 0x1,
+	RTL8366RB_LEDGROUP_LINK_ACT		= 0x2,
+	RTL8366RB_LEDGROUP_SPD1000		= 0x3,
+	RTL8366RB_LEDGROUP_SPD100		= 0x4,
+	RTL8366RB_LEDGROUP_SPD10		= 0x5,
+	RTL8366RB_LEDGROUP_SPD1000_ACT		= 0x6,
+	RTL8366RB_LEDGROUP_SPD100_ACT		= 0x7,
+	RTL8366RB_LEDGROUP_SPD10_ACT		= 0x8,
+	RTL8366RB_LEDGROUP_SPD100_10_ACT	= 0x9,
+	RTL8366RB_LEDGROUP_FIBER		= 0xa,
+	RTL8366RB_LEDGROUP_AN_FAULT		= 0xb,
+	RTL8366RB_LEDGROUP_LINK_RX		= 0xc,
+	RTL8366RB_LEDGROUP_LINK_TX		= 0xd,
+	RTL8366RB_LEDGROUP_MASTER		= 0xe,
+	RTL8366RB_LEDGROUP_FORCE		= 0xf,
+
+	__RTL8366RB_LEDGROUP_MODE_MAX
+};
+
+struct rtl8366rb_led {
+	u8 port_num;
+	u8 led_group;
+	struct realtek_priv *priv;
+	struct led_classdev cdev;
+};
+
 /**
  * struct rtl8366rb - RTL8366RB-specific data
  * @max_mtu: per-port max MTU setting
  * @pvid_enabled: if PVID is set for respective port
+ * @leds: per-port and per-ledgroup led info
  */
 struct rtl8366rb {
 	unsigned int max_mtu[RTL8366RB_NUM_PORTS];
 	bool pvid_enabled[RTL8366RB_NUM_PORTS];
+	struct rtl8366rb_led leds[RTL8366RB_NUM_PORTS][RTL8366RB_NUM_LEDGROUPS];
 };
 
 static struct rtl8366_mib_counter rtl8366rb_mib_counters[] = {
@@ -809,6 +830,217 @@ static int rtl8366rb_jam_table(const struct rtl8366rb_jam_tbl_entry *jam_table,
 	return 0;
 }
 
+static int rb8366rb_set_ledgroup_mode(struct realtek_priv *priv,
+				      u8 led_group,
+				      enum rtl8366_ledgroup_mode mode)
+{
+	int ret;
+	u32 val;
+
+	val = mode << RTL8366RB_LED_CTRL_OFFSET(led_group);
+
+	ret = regmap_update_bits(priv->map,
+				 RTL8366RB_LED_CTRL_REG,
+				 RTL8366RB_LED_CTRL_MASK(led_group),
+				 val);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static inline u32 rtl8366rb_led_group_port_mask(u8 led_group, u8 port)
+{
+	switch (led_group) {
+	case 0:
+		return FIELD_PREP(RTL8366RB_LED_0_X_CTRL_MASK, BIT(port));
+	case 1:
+		return FIELD_PREP(RTL8366RB_LED_0_X_CTRL_MASK, BIT(port));
+	case 2:
+		return FIELD_PREP(RTL8366RB_LED_0_X_CTRL_MASK, BIT(port));
+	case 3:
+		return FIELD_PREP(RTL8366RB_LED_0_X_CTRL_MASK, BIT(port));
+	default:
+		return 0;
+	}
+}
+
+static int rb8366rb_get_port_led(struct rtl8366rb_led *led)
+{
+	struct realtek_priv *priv = led->priv;
+	u8 led_group = led->led_group;
+	u8 port_num = led->port_num;
+	int ret;
+	u32 val;
+
+	ret = regmap_read(priv->map, RTL8366RB_LED_X_X_CTRL_REG(led_group),
+			  &val);
+	if (ret) {
+		dev_err(priv->dev, "error reading LED on port %d group %d\n",
+			led_group, port_num);
+		return ret;
+	}
+
+	return !!(val & rtl8366rb_led_group_port_mask(led_group, port_num));
+}
+
+static int rb8366rb_set_port_led(struct rtl8366rb_led *led, bool enable)
+{
+	struct realtek_priv *priv = led->priv;
+	u8 led_group = led->led_group;
+	u8 port_num = led->port_num;
+	int ret;
+
+	ret = regmap_update_bits(priv->map,
+				 RTL8366RB_LED_X_X_CTRL_REG(led_group),
+				 rtl8366rb_led_group_port_mask(led_group,
+							       port_num),
+				 enable ? 0xffff : 0);
+	if (ret) {
+		dev_err(priv->dev, "error updating LED on port %d group %d\n",
+			led_group, port_num);
+		return ret;
+	}
+
+	/* Change the LED group to manual controlled LEDs if required */
+	ret = rb8366rb_set_ledgroup_mode(priv, led_group,
+					 RTL8366RB_LEDGROUP_FORCE);
+
+	if (ret) {
+		dev_err(priv->dev, "error updating LED GROUP group %d\n",
+			led_group);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int
+rtl8366rb_cled_brightness_set_blocking(struct led_classdev *ldev,
+				       enum led_brightness brightness)
+{
+	struct rtl8366rb_led *led = container_of(ldev, struct rtl8366rb_led,
+						 cdev);
+
+	return rb8366rb_set_port_led(led, brightness == LED_ON);
+}
+
+static int rtl8366rb_setup_led(struct realtek_priv *priv, struct dsa_port *dp,
+			       struct fwnode_handle *led_fwnode)
+{
+	struct rtl8366rb *rb = priv->chip_data;
+	struct led_init_data init_data = { };
+	enum led_default_state state;
+	struct rtl8366rb_led *led;
+	u32 led_group;
+	int ret;
+
+	ret = fwnode_property_read_u32(led_fwnode, "reg", &led_group);
+	if (ret)
+		return ret;
+
+	if (led_group >= RTL8366RB_NUM_LEDGROUPS) {
+		dev_warn(priv->dev, "Invalid LED reg %d defined for port %d",
+			 led_group, dp->index);
+		return -EINVAL;
+	}
+
+	led = &rb->leds[dp->index][led_group];
+	led->port_num = dp->index;
+	led->led_group = led_group;
+	led->priv = priv;
+
+	state = led_init_default_state_get(led_fwnode);
+	switch (state) {
+	case LEDS_DEFSTATE_ON:
+		led->cdev.brightness = 1;
+		rb8366rb_set_port_led(led, 1);
+		break;
+	case LEDS_DEFSTATE_KEEP:
+		led->cdev.brightness =
+			rb8366rb_get_port_led(led);
+		break;
+	case LEDS_DEFSTATE_OFF:
+	default:
+		led->cdev.brightness = 0;
+		rb8366rb_set_port_led(led, 0);
+	}
+
+	led->cdev.max_brightness = 1;
+	led->cdev.brightness_set_blocking =
+		rtl8366rb_cled_brightness_set_blocking;
+	init_data.fwnode = led_fwnode;
+	init_data.devname_mandatory = true;
+
+	init_data.devicename = kasprintf(GFP_KERNEL, "Realtek-%d:0%d:%d",
+					 dp->ds->index, dp->index, led_group);
+	if (!init_data.devicename)
+		return -ENOMEM;
+
+	ret = devm_led_classdev_register_ext(priv->dev, &led->cdev, &init_data);
+	if (ret) {
+		dev_warn(priv->dev, "Failed to init LED %d for port %d",
+			 led_group, dp->index);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rtl8366rb_setup_all_leds_off(struct realtek_priv *priv)
+{
+	int ret = 0;
+	int i;
+
+	regmap_update_bits(priv->map,
+			   RTL8366RB_INTERRUPT_CONTROL_REG,
+			   RTL8366RB_P4_RGMII_LED,
+			   0);
+
+	for (i = 0; i < RTL8366RB_NUM_LEDGROUPS; i++) {
+		ret = rb8366rb_set_ledgroup_mode(priv, i,
+						 RTL8366RB_LEDGROUP_OFF);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int rtl8366rb_setup_leds(struct realtek_priv *priv)
+{
+	struct device_node *leds_np, *led_np;
+	struct dsa_switch *ds = &priv->ds;
+	struct dsa_port *dp;
+	int ret = 0;
+
+	dsa_switch_for_each_port(dp, ds) {
+		if (!dp->dn)
+			continue;
+
+		leds_np = of_get_child_by_name(dp->dn, "leds");
+		if (!leds_np) {
+			dev_dbg(priv->dev, "No leds defined for port %d",
+				dp->index);
+			continue;
+		}
+
+		for_each_child_of_node(leds_np, led_np) {
+			ret = rtl8366rb_setup_led(priv, dp,
+						  of_fwnode_handle(led_np));
+			if (ret) {
+				of_node_put(led_np);
+				break;
+			}
+		}
+
+		of_node_put(leds_np);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
 static int rtl8366rb_setup(struct dsa_switch *ds)
 {
 	struct realtek_priv *priv = ds->priv;
@@ -817,7 +1049,6 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
 	u32 chip_ver = 0;
 	u32 chip_id = 0;
 	int jam_size;
-	u32 val;
 	int ret;
 	int i;
 
@@ -997,7 +1228,9 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
 	if (ret)
 		return ret;
 
-	/* Set blinking, TODO: make this configurable */
+	/* Set blinking, used by all LED groups using HW triggers.
+	 * TODO: make this configurable
+	 */
 	ret = regmap_update_bits(priv->map, RTL8366RB_LED_BLINKRATE_REG,
 				 RTL8366RB_LED_BLINKRATE_MASK,
 				 RTL8366RB_LED_BLINKRATE_56MS);
@@ -1005,26 +1238,19 @@ static int rtl8366rb_setup(struct dsa_switch *ds)
 		return ret;
 
 	/* Set up LED activity:
-	 * Each port has 4 LEDs, we configure all ports to the same
-	 * behaviour (no individual config) but we can set up each
-	 * LED separately.
+	 * Each port has 4 LEDs on fixed groups. Each group shares the same
+	 * hardware trigger across all ports. LEDs can only be indiviually
+	 * controlled setting the LED group to fixed mode and using the driver
+	 * to toggle them LEDs on/off.
 	 */
 	if (priv->leds_disabled) {
-		/* Turn everything off */
-		regmap_update_bits(priv->map,
-				   RTL8366RB_INTERRUPT_CONTROL_REG,
-				   RTL8366RB_P4_RGMII_LED,
-				   0);
-
-		for (i = 0; i < RTL8366RB_NUM_LEDGROUPS; i++) {
-			val = RTL8366RB_LED_OFF << RTL8366RB_LED_CTRL_OFFSET(i);
-			ret = regmap_update_bits(priv->map,
-						 RTL8366RB_LED_CTRL_REG,
-						 RTL8366RB_LED_CTRL_MASK(i),
-						 val);
-			if (ret)
-				return ret;
-		}
+		ret = rtl8366rb_setup_all_leds_off(priv);
+		if (ret)
+			return ret;
+	} else {
+		ret = rtl8366rb_setup_leds(priv);
+		if (ret)
+			return ret;
 	}
 
 	ret = rtl8366_reset_vlan(priv);