[net-next,v1,2/3] net: phy: add API for LEDs controlled by ethernet PHY chips

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 698bea312adc6..6ab8956c49b06 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -61,6 +61,10 @@  config SFP
 	depends on HWMON || HWMON=n
 	select MDIO_I2C
 
+config PHY_LEDS
+	bool
+	default y if LEDS_TRIGGERS
+
 comment "MII PHY device drivers"
 
 config AMD_PHY
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index a13e402074cf8..8a54fb30a729d 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -20,6 +20,7 @@  endif
 obj-$(CONFIG_MDIO_DEVRES)	+= mdio_devres.o
 libphy-$(CONFIG_SWPHY)		+= swphy.o
 libphy-$(CONFIG_LED_TRIGGER_PHY)	+= phy_led_triggers.o
+libphy-$(CONFIG_PHY_LEDS)		+= phy_led.o
 
 obj-$(CONFIG_PHYLINK)		+= phylink.o
 obj-$(CONFIG_PHYLIB)		+= libphy.o
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 8adfbad0a1e8f..8a28134841ec3 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -9,6 +9,7 @@ 
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/atomic.h>
 #include <linux/bitmap.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
@@ -892,6 +893,7 @@  EXPORT_SYMBOL(get_phy_device);
  */
 int phy_device_register(struct phy_device *phydev)
 {
+	static atomic_t phyindex;
 	int err;
 
 	err = mdiobus_register_device(&phydev->mdio);
@@ -908,6 +910,7 @@  int phy_device_register(struct phy_device *phydev)
 		goto out;
 	}
 
+	phydev->phyindex = atomic_inc_return(&phyindex) - 1;
 	err = device_add(&phydev->mdio.dev);
 	if (err) {
 		phydev_err(phydev, "failed to add\n");
@@ -2909,6 +2912,8 @@  static int phy_probe(struct device *dev)
 				 phydev->supported);
 	}
 
+	of_phy_register_leds(phydev);
+
 	/* Set the state to READY by default */
 	phydev->state = PHY_READY;
 
@@ -3040,24 +3045,32 @@  static int __init phy_init(void)
 {
 	int rc;
 
-	rc = mdio_bus_init();
+	rc = phy_leds_init();
 	if (rc)
 		return rc;
 
+	rc = mdio_bus_init();
+	if (rc)
+		goto err_leds;
+
 	ethtool_set_ethtool_phy_ops(&phy_ethtool_phy_ops);
 	features_init();
 
 	rc = phy_driver_register(&genphy_c45_driver, THIS_MODULE);
 	if (rc)
-		goto err_c45;
+		goto err_mdio;
 
 	rc = phy_driver_register(&genphy_driver, THIS_MODULE);
-	if (rc) {
-		phy_driver_unregister(&genphy_c45_driver);
-err_c45:
-		mdio_bus_exit();
-	}
+	if (rc)
+		goto err_c45;
 
+	return 0;
+err_c45:
+	phy_driver_unregister(&genphy_c45_driver);
+err_mdio:
+	mdio_bus_exit();
+err_leds:
+	phy_leds_exit();
 	return rc;
 }
 
@@ -3067,6 +3080,7 @@  static void __exit phy_exit(void)
 	phy_driver_unregister(&genphy_driver);
 	mdio_bus_exit();
 	ethtool_set_ethtool_phy_ops(NULL);
+	phy_leds_exit();
 }
 
 subsys_initcall(phy_init);
diff --git a/drivers/net/phy/phy_led.c b/drivers/net/phy/phy_led.c
new file mode 100644
index 0000000000000..80d203b41c92e
--- /dev/null
+++ b/drivers/net/phy/phy_led.c
@@ -0,0 +1,224 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/* drivers/net/phy/phy_hw_led_mode.c
+ *
+ * PHY HW LED mode trigger
+ *
+ * Copyright (C) 2020 Marek Behun <marek.behun@nic.cz>
+ */
+#include <linux/leds.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+
+int phy_led_brightness_set(struct led_classdev *cdev, enum led_brightness brightness)
+{
+	struct phy_device_led *led = led_cdev_to_phy_device_led(cdev);
+	struct phy_device *phydev = to_phy_device(cdev->dev->parent);
+	int ret;
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->led_ops->led_brightness_set(phydev, led, brightness);
+	mutex_unlock(&phydev->lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_led_brightness_set);
+
+static int of_phy_register_led(struct phy_device *phydev, struct device_node *np)
+{
+	struct phy_device_led_init_data pdata = {};
+	struct led_init_data init_data = {};
+	struct phy_device_led *led;
+	char devicename[16];
+	u32 reg;
+	int ret;
+
+	ret = of_property_read_u32(np, "reg", &reg);
+	if (ret < 0)
+		return ret;
+
+	led = devm_kzalloc(&phydev->mdio.dev, sizeof(struct phy_device_led), GFP_KERNEL);
+	if (!led)
+		return -ENOMEM;
+
+	led->cdev.brightness_set_blocking = phy_led_brightness_set;
+	led->cdev.trigger_type = &phy_hw_led_trig_type;
+	led->addr = reg;
+
+	of_property_read_string(np, "linux,default-trigger", &led->cdev.default_trigger);
+	of_property_read_string(np, "linux,default-hw-mode", &led->hw_mode);
+
+	pdata.active_low = !of_property_read_bool(np, "enable-active-high");
+	pdata.open_drain = of_property_read_bool(np, "led-open-drain");
+
+	init_data.fwnode = &np->fwnode;
+	init_data.devname_mandatory = true;
+	snprintf(devicename, sizeof(devicename), "phy%d", phydev->phyindex);
+	init_data.devicename = devicename;
+
+	ret = phydev->led_ops->led_init(phydev, led, &pdata);
+	if (ret < 0)
+		goto err_free;
+
+	ret = devm_led_classdev_register_ext(&phydev->mdio.dev, &led->cdev, &init_data);
+	if (ret < 0)
+		goto err_free;
+
+	led->flags |= PHY_DEVICE_LED_REGISTERED;
+
+	return 0;
+err_free:
+	devm_kfree(&phydev->mdio.dev, led);
+	return ret;
+}
+
+int of_phy_register_leds(struct phy_device *phydev)
+{
+	struct device_node *node = phydev->mdio.dev.of_node;
+	struct device_node *leds, *led;
+	int ret;
+
+	if (!IS_ENABLED(CONFIG_OF_MDIO))
+		return 0;
+
+	if (!phydev->drv->led_ops)
+		return 0;
+
+	phydev->led_ops = phydev->drv->led_ops;
+
+	leds = of_get_child_by_name(node, "leds");
+	if (!leds)
+		return 0;
+
+	for_each_available_child_of_node(leds, led) {
+		ret = of_phy_register_led(phydev, led);
+		if (ret < 0)
+			phydev_err(phydev, "Nonfatal error: cannot register LED from node %pOFn: %i\n",
+				   led, ret);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_phy_register_leds);
+
+static int phy_hw_led_trig_activate(struct led_classdev *cdev)
+{
+	struct phy_device *phydev = to_phy_device(cdev->dev->parent);
+	struct phy_device_led *led;
+	int ret;
+
+	led = led_cdev_to_phy_device_led(cdev);
+
+	if (!led->hw_mode)
+		return 0;
+
+	/* When this trigger is being activated from devm_led_classdev_register_ext, the mutex is
+	 * already locked (in phy_probe), so only lock/unlock it if the LED is already registered.
+	 */
+	if (led->flags & PHY_DEVICE_LED_REGISTERED)
+		mutex_lock(&phydev->lock);
+
+	ret = phydev->led_ops->led_set_hw_mode(phydev, led, led->hw_mode);
+
+	if (led->flags & PHY_DEVICE_LED_REGISTERED)
+		mutex_unlock(&phydev->lock);
+
+	if (ret < 0)
+		phydev_warn(phydev, "could not set HW mode %s on LED %s: %i\n", led->hw_mode,
+			    cdev->name, ret);
+
+	/* don't fail to activate this trigger so that user can write hw_mode file */
+	return 0;
+}
+
+static void phy_hw_led_trig_deactivate(struct led_classdev *cdev)
+{
+	struct phy_device *phydev = to_phy_device(cdev->dev->parent);
+	struct phy_device_led *led;
+	int ret;
+
+	led = led_cdev_to_phy_device_led(cdev);
+
+	mutex_lock(&phydev->lock);
+
+	/* store HW mode before deactivation */
+	led->hw_mode = phydev->led_ops->led_get_hw_mode(phydev, led);
+
+	ret = phydev->led_ops->led_set_hw_mode(phydev, led_cdev_to_phy_device_led(cdev), NULL);
+
+	mutex_unlock(&phydev->lock);
+
+	if (ret < 0)
+		phydev_err(phydev, "failed deactivating HW mode on LED %s\n", cdev->name);
+}
+
+static ssize_t hw_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct phy_device *phydev = to_phy_device(dev->parent);
+	const char *mode, *cur_mode;
+	struct phy_device_led *led;
+	void *iter = NULL;
+	int len = 0;
+
+	led = led_cdev_to_phy_device_led(led_trigger_get_led(dev));
+
+	mutex_lock(&phydev->lock);
+
+	cur_mode = phydev->led_ops->led_get_hw_mode(phydev, led);
+
+	for (mode = phydev->led_ops->led_iter_hw_mode(phydev, led, &iter);
+	     mode;
+	     mode = phydev->led_ops->led_iter_hw_mode(phydev, led, &iter)) {
+		bool sel;
+
+		sel = cur_mode && !strcmp(mode, cur_mode);
+
+		len += scnprintf(buf + len, PAGE_SIZE - len, "%s%s%s ", sel ? "[" : "", mode,
+				 sel ? "]" : "");
+	}
+
+	if (buf[len - 1] == ' ')
+		buf[len - 1] = '\n';
+
+	mutex_unlock(&phydev->lock);
+
+	return len;
+}
+
+static ssize_t hw_mode_store(struct device *dev, struct device_attribute *attr, const char *buf,
+			     size_t count)
+{
+	struct phy_device *phydev = to_phy_device(dev->parent);
+	struct phy_device_led *led;
+	int ret;
+
+	led = led_cdev_to_phy_device_led(led_trigger_get_led(dev));
+
+	mutex_lock(&phydev->lock);
+	ret = phydev->led_ops->led_set_hw_mode(phydev, led, buf);
+	mutex_unlock(&phydev->lock);
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(hw_mode);
+
+static struct attribute *phy_hw_led_trig_attrs[] = {
+	&dev_attr_hw_mode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(phy_hw_led_trig);
+
+struct led_hw_trigger_type phy_hw_led_trig_type;
+EXPORT_SYMBOL_GPL(phy_hw_led_trig_type);
+
+struct led_trigger phy_hw_led_trig = {
+	.name		= "phydev-hw-mode",
+	.activate	= phy_hw_led_trig_activate,
+	.deactivate	= phy_hw_led_trig_deactivate,
+	.trigger_type	= &phy_hw_led_trig_type,
+	.groups		= phy_hw_led_trig_groups,
+};
+EXPORT_SYMBOL_GPL(phy_hw_led_trig);
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 3a09d2bf69ea4..2c651375becd1 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.h>
 #include <linux/linkmode.h>
 #include <linux/netlink.h>
 #include <linux/mdio.h>
@@ -406,6 +407,7 @@  struct macsec_ops;
 /* phy_device: An instance of a PHY
  *
  * drv: Pointer to the driver for this PHY instance
+ * phyindex: a simple incrementing PHY index
  * phy_id: UID for this device found during discovery
  * c45_ids: 802.3-c45 Device Identifers if is_c45.
  * is_c45:  Set to true if this phy uses clause 45 addressing.
@@ -420,6 +422,7 @@  struct macsec_ops;
  * downshifted_rate: Set true if link speed has been downshifted.
  * state: state of the PHY for management purposes
  * dev_flags: Device-specific flags used by the PHY driver.
+ * led_ops: PHY connected LEDs ops
  * irq: IRQ number of the PHY's interrupt (-1 if none)
  * phy_timer: The timer for handling the state machine
  * sfp_bus_attached: flag indicating whether the SFP bus has been attached
@@ -446,6 +449,8 @@  struct phy_device {
 	/* And management functions */
 	struct phy_driver *drv;
 
+	int phyindex;
+
 	u32 phy_id;
 
 	struct phy_c45_device_ids c45_ids;
@@ -505,6 +510,10 @@  struct phy_device {
 	struct phy_led_trigger *led_link_trigger;
 #endif
 
+#if IS_ENABLED(CONFIG_PHY_LEDS)
+	const struct phy_device_led_ops *led_ops;
+#endif
+
 	/*
 	 * Interrupt number for this PHY
 	 * -1 means no interrupt
@@ -562,6 +571,85 @@  struct phy_tdr_config {
 };
 #define PHY_PAIR_ALL -1
 
+struct phy_device_led_init_data {
+	bool active_low;
+	bool open_drain;
+};
+
+#define PHY_DEVICE_LED_REGISTERED	BIT(31)
+
+/* PHY LEDs support */
+struct phy_device_led {
+	struct led_classdev cdev;
+	const char *hw_mode;
+	int addr;
+	u32 flags;
+};
+#define led_cdev_to_phy_device_led(l) container_of(l, struct phy_device_led, cdev)
+
+/* struct phy_device_led_ops: Operations on LEDs controlled by PHY chips
+ *
+ * All the following operations must be implemented:
+ * @led_init: Should initialize LED from init_data (and check whether they are correct).
+ *            This should also set led->cdev.max_brightness, for example.
+ * @led_brightness_set: Sets brightness.
+ * @led_iter_hw_mode: Iterates available HW control mode names for this LED.
+ * @led_set_hw_mode: Sets HW control mode to value specified by given name.
+ * @led_get_hw_mode: Returns current HW control mode name.
+ *
+ * This methods must not lock the phy_device lock mutex. When they are called, the mutex
+ * is already locked.
+ */
+struct phy_device_led_ops {
+	int (*led_init)(struct phy_device *dev, struct phy_device_led *led,
+			const struct phy_device_led_init_data *pdata);
+	int (*led_brightness_set)(struct phy_device *dev, struct phy_device_led *led,
+				  enum led_brightness brightness);
+	const char *(*led_iter_hw_mode)(struct phy_device *dev, struct phy_device_led *led,
+					void **iter);
+	int (*led_set_hw_mode)(struct phy_device *dev, struct phy_device_led *led,
+			       const char *mode);
+	const char *(*led_get_hw_mode)(struct phy_device *dev, struct phy_device_led *led);
+};
+
+#if IS_ENABLED(CONFIG_PHY_LEDS)
+
+#define phy_device_led_ops_ptr(s) (s)
+
+int of_phy_register_leds(struct phy_device *phydev);
+
+extern struct led_hw_trigger_type phy_hw_led_trig_type;
+extern struct led_trigger phy_hw_led_trig;
+int phy_led_brightness_set(struct led_classdev *cdev, enum led_brightness brightness);
+
+static inline int phy_leds_init(void)
+{
+	return led_trigger_register(&phy_hw_led_trig);
+}
+
+static inline void phy_leds_exit(void)
+{
+	led_trigger_unregister(&phy_hw_led_trig);
+}
+#else /* !IS_ENABLED(CONFIG_PHY_LEDS) */
+
+#define phy_device_led_ops_ptr(s) NULL
+
+static inline int of_phy_register_leds(struct phy_device *phydev)
+{
+	return 0;
+}
+
+static inline int phy_leds_init(void)
+{
+	return 0;
+}
+
+static inline void phy_leds_exit(void)
+{
+}
+#endif /* !IS_ENABLED(CONFIG_PHY_LEDS) */
+
 /* struct phy_driver: Driver structure for a particular PHY type
  *
  * driver_data: static driver data
@@ -738,6 +826,9 @@  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 LEDs operations */
+	const struct phy_device_led_ops *led_ops;
 };
 #define to_phy_driver(d) container_of(to_mdio_common_driver(d),		\
 				      struct phy_driver, mdiodrv)