[PATCH net-next + leds v2 5/7] net: phy: add support for LEDs controlled by ethernet PHY chips

[Marek Behún]

This patch uses the new API for HW controlled LEDs to add support for
probing and control of LEDs connected to an ethernet PHY chip.

A PHY driver wishing to utilize this API needs to implement the methods
in struct hw_controlled_led_ops and set the member led_ops in struct
phy_driver to point to that structure.

Signed-off-by: Marek Behún <marek.behun@xxxxxx>
---
 drivers/net/phy/phy_device.c | 103 +++++++++++++++++++++++++++++++++++
 include/linux/phy.h          |   4 ++
 2 files changed, 107 insertions(+)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 38f56d39f1229..54d5c88e4d4b2 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -2820,6 +2820,103 @@ static bool phy_drv_supports_irq(struct phy_driver *phydrv)
 	return phydrv->config_intr && phydrv->ack_interrupt;
 }
 
+#if IS_ENABLED(CONFIG_LEDS_HW_CONTROLLED)
+
+/* PHY mutex lock wrappers for operations on PHY HW controlled LEDs, so that PHY drivers
+ * implementing these operations don't have to lock phydev->lock themselves.
+ */
+static int phy_led_init(struct device *dev, struct hw_controlled_led *led)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	int ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->led_ops->led_init(dev, led);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+
+static int phy_led_brightness_set(struct device *dev, struct hw_controlled_led *led,
+				  enum led_brightness brightness)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	int ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->led_ops->led_brightness_set(dev, led, brightness);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+
+static const char *phy_led_iter_hw_mode(struct device *dev, struct hw_controlled_led *led,
+					void **iter)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	const char *ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->led_ops->led_iter_hw_mode(dev, led, iter);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+
+static int phy_led_set_hw_mode(struct device *dev, struct hw_controlled_led *led, const char *mode)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	int ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->led_ops->led_set_hw_mode(dev, led, mode);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+
+static const char *phy_led_get_hw_mode(struct device *dev, struct hw_controlled_led *led)
+{
+	struct phy_device *phydev = to_phy_device(dev);
+	const char *ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->drv->led_ops->led_get_hw_mode(dev, led);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+
+static const struct hw_controlled_led_ops phy_hw_controlled_led_ops = {
+	.led_init		= phy_led_init,
+	.led_brightness_set	= phy_led_brightness_set,
+	.led_iter_hw_mode	= phy_led_iter_hw_mode,
+	.led_set_hw_mode	= phy_led_set_hw_mode,
+	.led_get_hw_mode	= phy_led_get_hw_mode,
+};
+
+static int of_phy_probe_leds(struct phy_device *phydev)
+{
+	char devicename[32];
+
+	if (!phydev->drv->led_ops)
+		return 0;
+
+	snprintf(devicename, sizeof(devicename), "ethernet-phy%i", phydev->phyindex);
+
+	return of_register_hw_controlled_leds(&phydev->mdio.dev, devicename,
+					      &phy_hw_controlled_led_ops);
+}
+
+#else /* !IS_ENABLED(CONFIG_LEDS_HW_CONTROLLED) */
+
+static inline int of_phy_probe_leds(struct phy_device *phydev)
+{
+	return 0;
+}
+
+#endif /* !IS_ENABLED(CONFIG_LEDS_HW_CONTROLLED) */
+
 /**
  * phy_probe - probe and init a PHY device
  * @dev: device to probe and init
@@ -2922,6 +3019,12 @@ static int phy_probe(struct device *dev)
 
 	mutex_unlock(&phydev->lock);
 
+	/* LEDs have to be registered with phydev mutex unlocked, because some operations can be
+	 * called during registration that lock the mutex themselves
+	 */
+	if (!err)
+		of_phy_probe_leds(phydev);
+
 	return err;
 }
 
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 52881e21ad951..8a4ab72c74dd4 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -14,6 +14,7 @@
 #include <linux/compiler.h>
 #include <linux/spinlock.h>
 #include <linux/ethtool.h>
+#include <linux/leds-hw-controlled.h>
 #include <linux/linkmode.h>
 #include <linux/netlink.h>
 #include <linux/mdio.h>
@@ -741,6 +742,9 @@ struct phy_driver {
 	int (*set_loopback)(struct phy_device *dev, bool enable);
 	int (*get_sqi)(struct phy_device *dev);
 	int (*get_sqi_max)(struct phy_device *dev);
+
+	/* PHY connected and controlled LEDs */
+	const struct hw_controlled_led_ops *led_ops;
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)
-- 
2.26.2