net: dsa: qca8k: add LEDs blink_set() support

Add LEDs blink_set() support to qca8k Switch Family.
These LEDs support hw accellerated blinking at a fixed rate
of 4Hz.

Reject any other value since not supported by the LEDs switch.
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/qca/qca8k-leds.c

@@ -127,6 +127,43 @@ qca8k_led_brightness_get(struct qca8k_led *led)
 	return val == QCA8K_LED_ALWAYS_ON;
 }
 
+static int
+qca8k_cled_blink_set(struct led_classdev *ldev,
+		     unsigned long *delay_on,
+		     unsigned long *delay_off)
+{
+	struct qca8k_led *led = container_of(ldev, struct qca8k_led, cdev);
+	u32 mask, val = QCA8K_LED_ALWAYS_BLINK_4HZ;
+	struct qca8k_led_pattern_en reg_info;
+	struct qca8k_priv *priv = led->priv;
+
+	if (*delay_on == 0 && *delay_off == 0) {
+		*delay_on = 125;
+		*delay_off = 125;
+	}
+
+	if (*delay_on != 125 || *delay_off != 125) {
+		/* The hardware only supports blinking at 4Hz. Fall back
+		 * to software implementation in other cases.
+		 */
+		return -EINVAL;
+	}
+
+	qca8k_get_enable_led_reg(led->port_num, led->led_num, &reg_info);
+
+	if (led->port_num == 0 || led->port_num == 4) {
+		mask = QCA8K_LED_PATTERN_EN_MASK;
+		val <<= QCA8K_LED_PATTERN_EN_SHIFT;
+	} else {
+		mask = QCA8K_LED_PHY123_PATTERN_EN_MASK;
+	}
+
+	regmap_update_bits(priv->regmap, reg_info.reg, mask << reg_info.shift,
+			   val << reg_info.shift);
+
+	return 0;
+}
+
 static int
 qca8k_parse_port_leds(struct qca8k_priv *priv, struct fwnode_handle *port, int port_num)
 {
@@ -186,6 +223,7 @@ qca8k_parse_port_leds(struct qca8k_priv *priv, struct fwnode_handle *port, int p
 
 		port_led->cdev.max_brightness = 1;
 		port_led->cdev.brightness_set_blocking = qca8k_cled_brightness_set_blocking;
+		port_led->cdev.blink_set = qca8k_cled_blink_set;
 		init_data.default_label = ":port";
 		init_data.fwnode = led;
 		init_data.devname_mandatory = true;