igc: Add support for LEDs on i225/i226

Add support for LEDs on i225/i226. The LEDs can be controlled via sysfs
from user space using the netdev trigger. The LEDs are named as
igc-<bus><device>-<led> to be easily identified.

Offloading link speed and activity are supported. Other modes are simulated
in software by using on/off. Tested on Intel i225.

Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20240213184138.1483968-1-anthony.l.nguyen@intel.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/intel/Kconfig

@@ -368,6 +368,14 @@ config IGC
 
 	  To compile this driver as a module, choose M here. The module
 	  will be called igc.
+
+config IGC_LEDS
+	def_bool LEDS_TRIGGER_NETDEV
+	depends on IGC && LEDS_CLASS
+	help
+	  Optional support for controlling the NIC LED's with the netdev
+	  LED trigger.
+
 config IDPF
 	tristate "Intel(R) Infrastructure Data Path Function Support"
 	depends on PCI_MSI

drivers/net/ethernet/intel/igc/Makefile

@@ -6,6 +6,7 @@
 #
 
 obj-$(CONFIG_IGC) += igc.o
+igc-$(CONFIG_IGC_LEDS) += igc_leds.o
 
 igc-objs := igc_main.o igc_mac.o igc_i225.o igc_base.o igc_nvm.o igc_phy.o \
 igc_diag.o igc_ethtool.o igc_ptp.o igc_dump.o igc_tsn.o igc_xdp.o

drivers/net/ethernet/intel/igc/igc.h

@@ -295,6 +295,9 @@ struct igc_adapter {
 		struct timespec64 start;
 		struct timespec64 period;
 	} perout[IGC_N_PEROUT];
+
+	/* LEDs */
+	struct mutex led_mutex;
 };
 
 void igc_up(struct igc_adapter *adapter);
@@ -720,6 +723,8 @@ void igc_ptp_tx_hang(struct igc_adapter *adapter);
 void igc_ptp_read(struct igc_adapter *adapter, struct timespec64 *ts);
 void igc_ptp_tx_tstamp_event(struct igc_adapter *adapter);
 
+int igc_led_setup(struct igc_adapter *adapter);
+
 #define igc_rx_pg_size(_ring) (PAGE_SIZE << igc_rx_pg_order(_ring))
 
 #define IGC_TXD_DCMD	(IGC_ADVTXD_DCMD_EOP | IGC_ADVTXD_DCMD_RS)

drivers/net/ethernet/intel/igc/igc_leds.c

@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2024 Linutronix GmbH */
+
+#include <linux/bits.h>
+#include <linux/leds.h>
+#include <linux/netdevice.h>
+#include <linux/pm_runtime.h>
+#include <uapi/linux/uleds.h>
+
+#include "igc.h"
+
+#define IGC_NUM_LEDS			3
+
+#define IGC_LEDCTL_LED0_MODE_SHIFT	0
+#define IGC_LEDCTL_LED0_MODE_MASK	GENMASK(3, 0)
+#define IGC_LEDCTL_LED0_BLINK		BIT(7)
+#define IGC_LEDCTL_LED1_MODE_SHIFT	8
+#define IGC_LEDCTL_LED1_MODE_MASK	GENMASK(11, 8)
+#define IGC_LEDCTL_LED1_BLINK		BIT(15)
+#define IGC_LEDCTL_LED2_MODE_SHIFT	16
+#define IGC_LEDCTL_LED2_MODE_MASK	GENMASK(19, 16)
+#define IGC_LEDCTL_LED2_BLINK		BIT(23)
+
+#define IGC_LEDCTL_MODE_ON		0x00
+#define IGC_LEDCTL_MODE_OFF		0x01
+#define IGC_LEDCTL_MODE_LINK_10		0x05
+#define IGC_LEDCTL_MODE_LINK_100	0x06
+#define IGC_LEDCTL_MODE_LINK_1000	0x07
+#define IGC_LEDCTL_MODE_LINK_2500	0x08
+#define IGC_LEDCTL_MODE_ACTIVITY	0x0b
+
+#define IGC_SUPPORTED_MODES						 \
+	(BIT(TRIGGER_NETDEV_LINK_2500) | BIT(TRIGGER_NETDEV_LINK_1000) | \
+	 BIT(TRIGGER_NETDEV_LINK_100) | BIT(TRIGGER_NETDEV_LINK_10) |	 \
+	 BIT(TRIGGER_NETDEV_RX) | BIT(TRIGGER_NETDEV_TX))
+
+#define IGC_ACTIVITY_MODES					\
+	(BIT(TRIGGER_NETDEV_RX) | BIT(TRIGGER_NETDEV_TX))
+
+struct igc_led_classdev {
+	struct net_device *netdev;
+	struct led_classdev led;
+	int index;
+};
+
+#define lcdev_to_igc_ldev(lcdev)				\
+	container_of(lcdev, struct igc_led_classdev, led)
+
+static void igc_led_select(struct igc_adapter *adapter, int led,
+			   u32 *mask, u32 *shift, u32 *blink)
+{
+	switch (led) {
+	case 0:
+		*mask  = IGC_LEDCTL_LED0_MODE_MASK;
+		*shift = IGC_LEDCTL_LED0_MODE_SHIFT;
+		*blink = IGC_LEDCTL_LED0_BLINK;
+		break;
+	case 1:
+		*mask  = IGC_LEDCTL_LED1_MODE_MASK;
+		*shift = IGC_LEDCTL_LED1_MODE_SHIFT;
+		*blink = IGC_LEDCTL_LED1_BLINK;
+		break;
+	case 2:
+		*mask  = IGC_LEDCTL_LED2_MODE_MASK;
+		*shift = IGC_LEDCTL_LED2_MODE_SHIFT;
+		*blink = IGC_LEDCTL_LED2_BLINK;
+		break;
+	default:
+		*mask = *shift = *blink = 0;
+		netdev_err(adapter->netdev, "Unknown LED %d selected!\n", led);
+	}
+}
+
+static void igc_led_set(struct igc_adapter *adapter, int led, u32 mode,
+			bool blink)
+{
+	u32 shift, mask, blink_bit, ledctl;
+	struct igc_hw *hw = &adapter->hw;
+
+	igc_led_select(adapter, led, &mask, &shift, &blink_bit);
+
+	pm_runtime_get_sync(&adapter->pdev->dev);
+	mutex_lock(&adapter->led_mutex);
+
+	/* Set mode */
+	ledctl = rd32(IGC_LEDCTL);
+	ledctl &= ~mask;
+	ledctl |= mode << shift;
+
+	/* Configure blinking */
+	if (blink)
+		ledctl |= blink_bit;
+	else
+		ledctl &= ~blink_bit;
+	wr32(IGC_LEDCTL, ledctl);
+
+	mutex_unlock(&adapter->led_mutex);
+	pm_runtime_put(&adapter->pdev->dev);
+}
+
+static u32 igc_led_get(struct igc_adapter *adapter, int led)
+{
+	u32 shift, mask, blink_bit, ledctl;
+	struct igc_hw *hw = &adapter->hw;
+
+	igc_led_select(adapter, led, &mask, &shift, &blink_bit);
+
+	pm_runtime_get_sync(&adapter->pdev->dev);
+	mutex_lock(&adapter->led_mutex);
+	ledctl = rd32(IGC_LEDCTL);
+	mutex_unlock(&adapter->led_mutex);
+	pm_runtime_put(&adapter->pdev->dev);
+
+	return (ledctl & mask) >> shift;
+}
+
+static int igc_led_brightness_set_blocking(struct led_classdev *led_cdev,
+					   enum led_brightness brightness)
+{
+	struct igc_led_classdev *ldev = lcdev_to_igc_ldev(led_cdev);
+	struct igc_adapter *adapter = netdev_priv(ldev->netdev);
+	u32 mode;
+
+	if (brightness)
+		mode = IGC_LEDCTL_MODE_ON;
+	else
+		mode = IGC_LEDCTL_MODE_OFF;
+
+	netdev_dbg(adapter->netdev, "Set brightness for LED %d to mode %u!\n",
+		   ldev->index, mode);
+
+	igc_led_set(adapter, ldev->index, mode, false);
+
+	return 0;
+}
+
+static int igc_led_hw_control_is_supported(struct led_classdev *led_cdev,
+					   unsigned long flags)
+{
+	if (flags & ~IGC_SUPPORTED_MODES)
+		return -EOPNOTSUPP;
+
+	/* If Tx and Rx selected, activity can be offloaded unless some other
+	 * mode is selected as well.
+	 */
+	if ((flags & BIT(TRIGGER_NETDEV_TX)) &&
+	    (flags & BIT(TRIGGER_NETDEV_RX)) &&
+	    !(flags & ~IGC_ACTIVITY_MODES))
+		return 0;
+
+	/* Single Rx or Tx activity is not supported. */
+	if (flags & IGC_ACTIVITY_MODES)
+		return -EOPNOTSUPP;
+
+	/* Only one mode can be active at a given time. */
+	if (flags & (flags - 1))
+		return -EOPNOTSUPP;
+
+	return 0;
+}
+
+static int igc_led_hw_control_set(struct led_classdev *led_cdev,
+				  unsigned long flags)
+{
+	struct igc_led_classdev *ldev = lcdev_to_igc_ldev(led_cdev);
+	struct igc_adapter *adapter = netdev_priv(ldev->netdev);
+	u32 mode = IGC_LEDCTL_MODE_OFF;
+	bool blink = false;
+
+	if (flags & BIT(TRIGGER_NETDEV_LINK_10))
+		mode = IGC_LEDCTL_MODE_LINK_10;
+	if (flags & BIT(TRIGGER_NETDEV_LINK_100))
+		mode = IGC_LEDCTL_MODE_LINK_100;
+	if (flags & BIT(TRIGGER_NETDEV_LINK_1000))
+		mode = IGC_LEDCTL_MODE_LINK_1000;
+	if (flags & BIT(TRIGGER_NETDEV_LINK_2500))
+		mode = IGC_LEDCTL_MODE_LINK_2500;
+	if ((flags & BIT(TRIGGER_NETDEV_TX)) &&
+	    (flags & BIT(TRIGGER_NETDEV_RX)))
+		mode = IGC_LEDCTL_MODE_ACTIVITY;
+
+	netdev_dbg(adapter->netdev, "Set HW control for LED %d to mode %u!\n",
+		   ldev->index, mode);
+
+	/* blink is recommended for activity */
+	if (mode == IGC_LEDCTL_MODE_ACTIVITY)
+		blink = true;
+
+	igc_led_set(adapter, ldev->index, mode, blink);
+
+	return 0;
+}
+
+static int igc_led_hw_control_get(struct led_classdev *led_cdev,
+				  unsigned long *flags)
+{
+	struct igc_led_classdev *ldev = lcdev_to_igc_ldev(led_cdev);
+	struct igc_adapter *adapter = netdev_priv(ldev->netdev);
+	u32 mode;
+
+	mode = igc_led_get(adapter, ldev->index);
+
+	switch (mode) {
+	case IGC_LEDCTL_MODE_ACTIVITY:
+		*flags = BIT(TRIGGER_NETDEV_TX) | BIT(TRIGGER_NETDEV_RX);
+		break;
+	case IGC_LEDCTL_MODE_LINK_10:
+		*flags = BIT(TRIGGER_NETDEV_LINK_10);
+		break;
+	case IGC_LEDCTL_MODE_LINK_100:
+		*flags = BIT(TRIGGER_NETDEV_LINK_100);
+		break;
+	case IGC_LEDCTL_MODE_LINK_1000:
+		*flags = BIT(TRIGGER_NETDEV_LINK_1000);
+		break;
+	case IGC_LEDCTL_MODE_LINK_2500:
+		*flags = BIT(TRIGGER_NETDEV_LINK_2500);
+		break;
+	}
+
+	return 0;
+}
+
+static struct device *igc_led_hw_control_get_device(struct led_classdev *led_cdev)
+{
+	struct igc_led_classdev *ldev = lcdev_to_igc_ldev(led_cdev);
+
+	return &ldev->netdev->dev;
+}
+
+static void igc_led_get_name(struct igc_adapter *adapter, int index, char *buf,
+			     size_t buf_len)
+{
+	snprintf(buf, buf_len, "igc-%x%x-led%d",
+		 pci_domain_nr(adapter->pdev->bus),
+		 pci_dev_id(adapter->pdev), index);
+}
+
+static void igc_setup_ldev(struct igc_led_classdev *ldev,
+			   struct net_device *netdev, int index)
+{
+	struct igc_adapter *adapter = netdev_priv(netdev);
+	struct led_classdev *led_cdev = &ldev->led;
+	char led_name[LED_MAX_NAME_SIZE];
+
+	ldev->netdev = netdev;
+	ldev->index = index;
+
+	igc_led_get_name(adapter, index, led_name, LED_MAX_NAME_SIZE);
+	led_cdev->name = led_name;
+	led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+	led_cdev->max_brightness = 1;
+	led_cdev->brightness_set_blocking = igc_led_brightness_set_blocking;
+	led_cdev->hw_control_trigger = "netdev";
+	led_cdev->hw_control_is_supported = igc_led_hw_control_is_supported;
+	led_cdev->hw_control_set = igc_led_hw_control_set;
+	led_cdev->hw_control_get = igc_led_hw_control_get;
+	led_cdev->hw_control_get_device = igc_led_hw_control_get_device;
+
+	devm_led_classdev_register(&netdev->dev, led_cdev);
+}
+
+int igc_led_setup(struct igc_adapter *adapter)
+{
+	struct net_device *netdev = adapter->netdev;
+	struct device *dev = &netdev->dev;
+	struct igc_led_classdev *leds;
+	int i;
+
+	mutex_init(&adapter->led_mutex);
+
+	leds = devm_kcalloc(dev, IGC_NUM_LEDS, sizeof(*leds), GFP_KERNEL);
+	if (!leds)
+		return -ENOMEM;
+
+	for (i = 0; i < IGC_NUM_LEDS; i++)
+		igc_setup_ldev(leds + i, netdev, i);
+
+	return 0;
+}

drivers/net/ethernet/intel/igc/igc_main.c

@@ -6978,6 +6978,12 @@ static int igc_probe(struct pci_dev *pdev,
 
 	pm_runtime_put_noidle(&pdev->dev);
 
+	if (IS_ENABLED(CONFIG_IGC_LEDS)) {
+		err = igc_led_setup(adapter);
+		if (err)
+			goto err_register;
+	}
+
 	return 0;
 
 err_register:

drivers/net/ethernet/intel/igc/igc_regs.h

@@ -12,6 +12,7 @@
 #define IGC_MDIC		0x00020  /* MDI Control - RW */
 #define IGC_CONNSW		0x00034  /* Copper/Fiber switch control - RW */
 #define IGC_VET			0x00038  /* VLAN Ether Type - RW */
+#define IGC_LEDCTL		0x00E00	 /* LED Control - RW */
 #define IGC_I225_PHPM		0x00E14  /* I225 PHY Power Management */
 #define IGC_GPHY_VERSION	0x0001E  /* I225 gPHY Firmware Version */