net: phy: phy_device: Call into the PHY driver to set LED brightness

Linux LEDs can be software controlled via the brightness file in /sys.
LED drivers need to implement a brightness_set function which the core
will call. Implement an intermediary in phy_device, which will call
into the phy driver if it implements the necessary function.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/phy_device.c

@@ -2991,11 +2991,18 @@ static bool phy_drv_supports_irq(struct phy_driver *phydrv)
 	return phydrv->config_intr && phydrv->handle_interrupt;
 }
 
-/* Dummy implementation until calls into PHY driver are added */
 static int phy_led_set_brightness(struct led_classdev *led_cdev,
 				  enum led_brightness value)
 {
-	return 0;
+	struct phy_led *phyled = to_phy_led(led_cdev);
+	struct phy_device *phydev = phyled->phydev;
+	int err;
+
+	mutex_lock(&phydev->lock);
+	err = phydev->drv->led_brightness_set(phydev, phyled->index, value);
+	mutex_unlock(&phydev->lock);
+
+	return err;
 }
 
 static int of_phy_led(struct phy_device *phydev,
@@ -3012,12 +3019,14 @@ static int of_phy_led(struct phy_device *phydev,
 		return -ENOMEM;
 
 	cdev = &phyled->led_cdev;
+	phyled->phydev = phydev;
 
 	err = of_property_read_u8(led, "reg", &phyled->index);
 	if (err)
 		return err;
 
-	cdev->brightness_set_blocking = phy_led_set_brightness;
+	if (phydev->drv->led_brightness_set)
+		cdev->brightness_set_blocking = phy_led_set_brightness;
 	cdev->max_brightness = 1;
 	init_data.devicename = dev_name(&phydev->mdio.dev);
 	init_data.fwnode = of_fwnode_handle(led);

include/linux/phy.h

@@ -841,15 +841,19 @@ struct phy_plca_status {
  * struct phy_led: An LED driven by the PHY
  *
  * @list: List of LEDs
+ * @phydev: PHY this LED is attached to
  * @led_cdev: Standard LED class structure
  * @index: Number of the LED
  */
 struct phy_led {
 	struct list_head list;
+	struct phy_device *phydev;
 	struct led_classdev led_cdev;
 	u8 index;
 };
 
+#define to_phy_led(d) container_of(d, struct phy_led, led_cdev)
+
 /**
  * struct phy_driver - Driver structure for a particular PHY type
  *
@@ -1072,6 +1076,15 @@ struct phy_driver {
 	/** @get_plca_status: Return the current PLCA status info */
 	int (*get_plca_status)(struct phy_device *dev,
 			       struct phy_plca_status *plca_st);
+
+	/**
+	 * @led_brightness_set: Set a PHY LED brightness. Index
+	 * indicates which of the PHYs led should be set. Value
+	 * follows the standard LED class meaning, e.g. LED_OFF,
+	 * LED_HALF, LED_FULL.
+	 */
+	int (*led_brightness_set)(struct phy_device *dev,
+				  u8 index, enum led_brightness value);
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)