[PATCH v8 08/13] leds: trigger: netdev: add available mode sysfs attr

[Christian Marangi <ansuelsmth@gmail.com>]

Add avaiable_mode sysfs attr to show and give some details about the
supported modes and how they can be handled by the trigger.

this can be used to get an overview of the different modes currently
available and active.

A mode with [hardware] can hw blink.
A mode with [software] con blink with sw support.
A mode with [hardware][software] support both mode but will fallback to
sw mode if needed.
A mode with [unavailable] will reject any option and can't be enabled
due to hw limitation or current configuration.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
 drivers/leds/trigger/ledtrig-netdev.c | 41 +++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 6dd04f4d70ea..b992d617f406 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -35,6 +35,8 @@
  *         (has carrier) or not
  * tx -  LED blinks on transmitted data
  * rx -  LED blinks on receive data
+ * available_mode - Display available mode and how they can be handled
+ *                  by the LED
  *
  */
 
@@ -382,12 +384,51 @@ static ssize_t interval_store(struct device *dev,
 
 static DEVICE_ATTR_RW(interval);
 
+static ssize_t available_mode_show(struct device *dev,
+				   struct device_attribute *attr, char *buf)
+{
+	struct led_netdev_data *trigger_data = led_trigger_get_drvdata(dev);
+	struct netdev_led_attr_detail *detail;
+	bool support_hw_mode;
+	int i, len = 0;
+
+	for (i = 0; i < ARRAY_SIZE(attr_details); i++) {
+		detail = &attr_details[i];
+		support_hw_mode = led_trigger_blink_mode_is_supported(trigger_data->led_cdev,
+								      BIT(detail->bit));
+
+		len += sprintf(buf + len, "%s ", detail->name);
+
+		if (detail->hardware_only) {
+			if (trigger_data->net_dev || !support_hw_mode)
+				len += sprintf(buf + len, "[unavailable]");
+			else
+				len += sprintf(buf + len, "[hardware]");
+		} else {
+			len += sprintf(buf + len, "[software]");
+
+			if (support_hw_mode && !trigger_data->net_dev)
+				len += sprintf(buf + len, "[hardware]");
+		}
+
+		if (test_bit(detail->bit, &trigger_data->mode))
+			len += sprintf(buf + len, "[on]");
+
+		len += sprintf(buf + len, "\n");
+	}
+
+	return len;
+}
+
+static DEVICE_ATTR_RO(available_mode);
+
 static struct attribute *netdev_trig_attrs[] = {
 	&dev_attr_device_name.attr,
 	&dev_attr_link.attr,
 	&dev_attr_rx.attr,
 	&dev_attr_tx.attr,
 	&dev_attr_interval.attr,
+	&dev_attr_available_mode.attr,
 	NULL
 };
 ATTRIBUTE_GROUPS(netdev_trig);
-- 
2.38.1