[net-next PATCH v7 05/16] net: phy: Add a binding for PHY LEDs

From: Christian Marangi
Date: Mon Apr 17 2023 - 11:21:08 EST


From: Andrew Lunn <andrew@xxxxxxx>

Define common binding parsing for all PHY drivers with LEDs using
phylib. Parse the DT as part of the phy_probe and add LEDs to the
linux LED class infrastructure. For the moment, provide a dummy
brightness function, which will later be replaced with a call into the
PHY driver. This allows testing since the LED core might otherwise
reject an LED whose brightness cannot be set.

Add a dependency on LED_CLASS. It either needs to be built in, or not
enabled, since a modular build can result in linker errors.

Signed-off-by: Andrew Lunn <andrew@xxxxxxx>
Signed-off-by: Christian Marangi <ansuelsmth@xxxxxxxxx>
---
drivers/net/phy/Kconfig | 1 +
drivers/net/phy/phy_device.c | 76 ++++++++++++++++++++++++++++++++++++
include/linux/phy.h | 16 ++++++++
3 files changed, 93 insertions(+)

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 6b9525def973..b8cc49820ced 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -18,6 +18,7 @@ menuconfig PHYLIB
depends on NETDEVICES
select MDIO_DEVICE
select MDIO_DEVRES
+ depends on LEDS_CLASS || LEDS_CLASS=n
help
Ethernet controllers are usually attached to PHY
devices. This option provides infrastructure for
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 917ba84105fc..61b971251de5 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -19,10 +19,12 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/mdio.h>
#include <linux/mii.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/of.h>
#include <linux/netdevice.h>
#include <linux/phy.h>
#include <linux/phy_led_triggers.h>
@@ -674,6 +676,7 @@ struct phy_device *phy_device_create(struct mii_bus *bus, int addr, u32 phy_id,
device_initialize(&mdiodev->dev);

dev->state = PHY_DOWN;
+ INIT_LIST_HEAD(&dev->leds);

mutex_init(&dev->lock);
INIT_DELAYED_WORK(&dev->state_queue, phy_state_machine);
@@ -2988,6 +2991,74 @@ 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;
+}
+
+static int of_phy_led(struct phy_device *phydev,
+ struct device_node *led)
+{
+ struct device *dev = &phydev->mdio.dev;
+ struct led_init_data init_data = {};
+ struct led_classdev *cdev;
+ struct phy_led *phyled;
+ int err;
+
+ phyled = devm_kzalloc(dev, sizeof(*phyled), GFP_KERNEL);
+ if (!phyled)
+ return -ENOMEM;
+
+ cdev = &phyled->led_cdev;
+
+ err = of_property_read_u8(led, "reg", &phyled->index);
+ if (err)
+ return err;
+
+ 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);
+ init_data.devname_mandatory = true;
+
+ err = devm_led_classdev_register_ext(dev, cdev, &init_data);
+ if (err)
+ return err;
+
+ list_add(&phyled->list, &phydev->leds);
+
+ return 0;
+}
+
+static int of_phy_leds(struct phy_device *phydev)
+{
+ struct device_node *node = phydev->mdio.dev.of_node;
+ struct device_node *leds, *led;
+ int err;
+
+ if (!IS_ENABLED(CONFIG_OF_MDIO))
+ return 0;
+
+ if (!node)
+ return 0;
+
+ leds = of_get_child_by_name(node, "leds");
+ if (!leds)
+ return 0;
+
+ for_each_available_child_of_node(leds, led) {
+ err = of_phy_led(phydev, led);
+ if (err) {
+ of_node_put(led);
+ return err;
+ }
+ }
+
+ return 0;
+}
+
/**
* fwnode_mdio_find_device - Given a fwnode, find the mdio_device
* @fwnode: pointer to the mdio_device's fwnode
@@ -3183,6 +3254,11 @@ static int phy_probe(struct device *dev)
/* Set the state to READY by default */
phydev->state = PHY_READY;

+ /* Get the LEDs from the device tree, and instantiate standard
+ * LEDs for them.
+ */
+ err = of_phy_leds(phydev);
+
out:
/* Re-assert the reset signal on error */
if (err)
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 2f83cfc206e5..bd6b5e9bb729 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>
@@ -600,6 +601,7 @@ struct macsec_ops;
* @phy_num_led_triggers: Number of triggers in @phy_led_triggers
* @led_link_trigger: LED trigger for link up/down
* @last_triggered: last LED trigger for link speed
+ * @leds: list of PHY LED structures
* @master_slave_set: User requested master/slave configuration
* @master_slave_get: Current master/slave advertisement
* @master_slave_state: Current master/slave configuration
@@ -699,6 +701,7 @@ struct phy_device {

struct phy_led_trigger *led_link_trigger;
#endif
+ struct list_head leds;

/*
* Interrupt number for this PHY
@@ -834,6 +837,19 @@ struct phy_plca_status {
bool pst;
};

+/**
+ * struct phy_led: An LED driven by the PHY
+ *
+ * @list: List of LEDs
+ * @led_cdev: Standard LED class structure
+ * @index: Number of the LED
+ */
+struct phy_led {
+ struct list_head list;
+ struct led_classdev led_cdev;
+ u8 index;
+};
+
/**
* struct phy_driver - Driver structure for a particular PHY type
*
--
2.39.2