leds: trigger: netdev: add additional specific link duplex mode

Add additional modes for specific link duplex. Use ethtool APIs to get the
current link duplex and enable the LED accordingly. Under netdev event
handler the rtnl lock is already held and is not needed to be set to
access ethtool APIs.

This is especially useful for PHY and Switch that supports LEDs hw
control for specific link duplex.

Add additional modes:
- half_duplex: Turn on LED when link is half duplex
- full_duplex: Turn on LED when link is full duplex
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Lee Jones <lee@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/leds/trigger/ledtrig-netdev.c

@@ -55,6 +55,7 @@ struct led_netdev_data {
 
 	unsigned long mode;
 	int link_speed;
+	u8 duplex;
 
 	bool carrier_link_up;
 	bool hw_control;
@@ -98,6 +99,14 @@ static void set_baseline_state(struct led_netdev_data *trigger_data)
 		    trigger_data->link_speed == SPEED_1000)
 			blink_on = true;
 
+		if (test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) &&
+		    trigger_data->duplex == DUPLEX_HALF)
+			blink_on = true;
+
+		if (test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode) &&
+		    trigger_data->duplex == DUPLEX_FULL)
+			blink_on = true;
+
 		if (blink_on)
 			led_set_brightness(led_cdev,
 					   led_cdev->blink_brightness);
@@ -190,8 +199,10 @@ static void get_device_state(struct led_netdev_data *trigger_data)
 	if (!trigger_data->carrier_link_up)
 		return;
 
-	if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd))
+	if (!__ethtool_get_link_ksettings(trigger_data->net_dev, &cmd)) {
 		trigger_data->link_speed = cmd.base.speed;
+		trigger_data->duplex = cmd.base.duplex;
+	}
 }
 
 static ssize_t device_name_show(struct device *dev,
@@ -230,6 +241,7 @@ static int set_device_name(struct led_netdev_data *trigger_data,
 
 	trigger_data->carrier_link_up = false;
 	trigger_data->link_speed = SPEED_UNKNOWN;
+	trigger_data->duplex = DUPLEX_UNKNOWN;
 	if (trigger_data->net_dev != NULL) {
 		rtnl_lock();
 		get_device_state(trigger_data);
@@ -274,6 +286,8 @@ static ssize_t netdev_led_attr_show(struct device *dev, char *buf,
 	case TRIGGER_NETDEV_LINK_10:
 	case TRIGGER_NETDEV_LINK_100:
 	case TRIGGER_NETDEV_LINK_1000:
+	case TRIGGER_NETDEV_HALF_DUPLEX:
+	case TRIGGER_NETDEV_FULL_DUPLEX:
 	case TRIGGER_NETDEV_TX:
 	case TRIGGER_NETDEV_RX:
 		bit = attr;
@@ -302,6 +316,8 @@ static ssize_t netdev_led_attr_store(struct device *dev, const char *buf,
 	case TRIGGER_NETDEV_LINK_10:
 	case TRIGGER_NETDEV_LINK_100:
 	case TRIGGER_NETDEV_LINK_1000:
+	case TRIGGER_NETDEV_HALF_DUPLEX:
+	case TRIGGER_NETDEV_FULL_DUPLEX:
 	case TRIGGER_NETDEV_TX:
 	case TRIGGER_NETDEV_RX:
 		bit = attr;
@@ -348,6 +364,8 @@ DEFINE_NETDEV_TRIGGER(link, TRIGGER_NETDEV_LINK);
 DEFINE_NETDEV_TRIGGER(link_10, TRIGGER_NETDEV_LINK_10);
 DEFINE_NETDEV_TRIGGER(link_100, TRIGGER_NETDEV_LINK_100);
 DEFINE_NETDEV_TRIGGER(link_1000, TRIGGER_NETDEV_LINK_1000);
+DEFINE_NETDEV_TRIGGER(half_duplex, TRIGGER_NETDEV_HALF_DUPLEX);
+DEFINE_NETDEV_TRIGGER(full_duplex, TRIGGER_NETDEV_FULL_DUPLEX);
 DEFINE_NETDEV_TRIGGER(tx, TRIGGER_NETDEV_TX);
 DEFINE_NETDEV_TRIGGER(rx, TRIGGER_NETDEV_RX);
 
@@ -394,6 +412,8 @@ static struct attribute *netdev_trig_attrs[] = {
 	&dev_attr_link_10.attr,
 	&dev_attr_link_100.attr,
 	&dev_attr_link_1000.attr,
+	&dev_attr_full_duplex.attr,
+	&dev_attr_half_duplex.attr,
 	&dev_attr_rx.attr,
 	&dev_attr_tx.attr,
 	&dev_attr_interval.attr,
@@ -425,6 +445,7 @@ static int netdev_trig_notify(struct notifier_block *nb,
 
 	trigger_data->carrier_link_up = false;
 	trigger_data->link_speed = SPEED_UNKNOWN;
+	trigger_data->duplex = DUPLEX_UNKNOWN;
 	switch (evt) {
 	case NETDEV_CHANGENAME:
 		get_device_state(trigger_data);
@@ -487,7 +508,9 @@ static void netdev_trig_work(struct work_struct *work)
 		invert = test_bit(TRIGGER_NETDEV_LINK, &trigger_data->mode) ||
 			 test_bit(TRIGGER_NETDEV_LINK_10, &trigger_data->mode) ||
 			 test_bit(TRIGGER_NETDEV_LINK_100, &trigger_data->mode) ||
-			 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode);
+			 test_bit(TRIGGER_NETDEV_LINK_1000, &trigger_data->mode) ||
+			 test_bit(TRIGGER_NETDEV_HALF_DUPLEX, &trigger_data->mode) ||
+			 test_bit(TRIGGER_NETDEV_FULL_DUPLEX, &trigger_data->mode);
 		interval = jiffies_to_msecs(
 				atomic_read(&trigger_data->interval));
 		/* base state is ON (link present) */

include/linux/leds.h

@@ -558,6 +558,8 @@ enum led_trigger_netdev_modes {
 	TRIGGER_NETDEV_LINK_10,
 	TRIGGER_NETDEV_LINK_100,
 	TRIGGER_NETDEV_LINK_1000,
+	TRIGGER_NETDEV_HALF_DUPLEX,
+	TRIGGER_NETDEV_FULL_DUPLEX,
 	TRIGGER_NETDEV_TX,
 	TRIGGER_NETDEV_RX,