r8169: add support for LED's on RTL8168/RTL8101

This adds support for the LED's on most chip versions. Excluded are
the old non-PCIe versions and RTL8125. RTL8125 has a different LED
register layout, support for it will follow later.

LED's can be controlled from userspace using the netdev LED trigger.

Tested on RTL8168h.

Note: The driver can't know which LED's are actually physically
wired. Therefore not every LED device may represent a physically
available LED.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/Makefile

@@ -7,4 +7,7 @@ obj-$(CONFIG_8139CP) += 8139cp.o
 obj-$(CONFIG_8139TOO) += 8139too.o
 obj-$(CONFIG_ATP) += atp.o
 r8169-objs += r8169_main.o r8169_firmware.o r8169_phy_config.o
+ifdef CONFIG_LEDS_TRIGGER_NETDEV
+r8169-objs += r8169_leds.o
+endif
 obj-$(CONFIG_R8169) += r8169.o

drivers/net/ethernet/realtek/r8169.h

@@ -8,6 +8,7 @@
  * See MAINTAINERS file for support contact information.
  */
 
+#include <linux/netdevice.h>
 #include <linux/types.h>
 #include <linux/phy.h>
 
@@ -77,3 +78,9 @@ u16 rtl8168h_2_get_adc_bias_ioffset(struct rtl8169_private *tp);
 u8 rtl8168d_efuse_read(struct rtl8169_private *tp, int reg_addr);
 void r8169_hw_phy_config(struct rtl8169_private *tp, struct phy_device *phydev,
 			 enum mac_version ver);
+
+void r8169_get_led_name(struct rtl8169_private *tp, int idx,
+			char *buf, int buf_len);
+int rtl8168_get_led_mode(struct rtl8169_private *tp);
+int rtl8168_led_mod_ctrl(struct rtl8169_private *tp, u16 mask, u16 val);
+void rtl8168_init_leds(struct net_device *ndev);

drivers/net/ethernet/realtek/r8169_leds.c

+// SPDX-License-Identifier: GPL-2.0-only
+/* r8169_leds.c: Realtek 8169/8168/8101/8125 ethernet driver.
+ *
+ * Copyright (c) 2023 Heiner Kallweit <hkallweit1@gmail.com>
+ *
+ * See MAINTAINERS file for support contact information.
+ */
+
+#include <linux/leds.h>
+#include <linux/netdevice.h>
+#include <uapi/linux/uleds.h>
+
+#include "r8169.h"
+
+#define RTL8168_LED_CTRL_OPTION2	BIT(15)
+#define RTL8168_LED_CTRL_ACT		BIT(3)
+#define RTL8168_LED_CTRL_LINK_1000	BIT(2)
+#define RTL8168_LED_CTRL_LINK_100	BIT(1)
+#define RTL8168_LED_CTRL_LINK_10	BIT(0)
+
+#define RTL8168_NUM_LEDS		3
+
+#define RTL8168_SUPPORTED_MODES \
+	(BIT(TRIGGER_NETDEV_LINK_1000) | BIT(TRIGGER_NETDEV_LINK_100) | \
+	 BIT(TRIGGER_NETDEV_LINK_10) | BIT(TRIGGER_NETDEV_RX) | \
+	 BIT(TRIGGER_NETDEV_TX))
+
+struct r8169_led_classdev {
+	struct led_classdev led;
+	struct net_device *ndev;
+	int index;
+};
+
+#define lcdev_to_r8169_ldev(lcdev) container_of(lcdev, struct r8169_led_classdev, led)
+
+static int rtl8168_led_hw_control_is_supported(struct led_classdev *led_cdev,
+					       unsigned long flags)
+{
+	struct r8169_led_classdev *ldev = lcdev_to_r8169_ldev(led_cdev);
+	struct rtl8169_private *tp = netdev_priv(ldev->ndev);
+	int shift = ldev->index * 4;
+	bool rx, tx;
+
+	if (flags & ~RTL8168_SUPPORTED_MODES)
+		goto nosupp;
+
+	rx = flags & BIT(TRIGGER_NETDEV_RX);
+	tx = flags & BIT(TRIGGER_NETDEV_TX);
+	if (rx != tx)
+		goto nosupp;
+
+	return 0;
+
+nosupp:
+	/* Switch LED off to indicate that mode isn't supported */
+	rtl8168_led_mod_ctrl(tp, 0x000f << shift, 0);
+	return -EOPNOTSUPP;
+}
+
+static int rtl8168_led_hw_control_set(struct led_classdev *led_cdev,
+				      unsigned long flags)
+{
+	struct r8169_led_classdev *ldev = lcdev_to_r8169_ldev(led_cdev);
+	struct rtl8169_private *tp = netdev_priv(ldev->ndev);
+	int shift = ldev->index * 4;
+	u16 mode = 0;
+
+	if (flags & BIT(TRIGGER_NETDEV_LINK_10))
+		mode |= RTL8168_LED_CTRL_LINK_10;
+	if (flags & BIT(TRIGGER_NETDEV_LINK_100))
+		mode |= RTL8168_LED_CTRL_LINK_100;
+	if (flags & BIT(TRIGGER_NETDEV_LINK_1000))
+		mode |= RTL8168_LED_CTRL_LINK_1000;
+	if (flags & BIT(TRIGGER_NETDEV_TX))
+		mode |= RTL8168_LED_CTRL_ACT;
+
+	return rtl8168_led_mod_ctrl(tp, 0x000f << shift, mode << shift);
+}
+
+static int rtl8168_led_hw_control_get(struct led_classdev *led_cdev,
+				      unsigned long *flags)
+{
+	struct r8169_led_classdev *ldev = lcdev_to_r8169_ldev(led_cdev);
+	struct rtl8169_private *tp = netdev_priv(ldev->ndev);
+	int shift = ldev->index * 4;
+	int mode;
+
+	mode = rtl8168_get_led_mode(tp);
+	if (mode < 0)
+		return mode;
+
+	if (mode & RTL8168_LED_CTRL_OPTION2) {
+		rtl8168_led_mod_ctrl(tp, RTL8168_LED_CTRL_OPTION2, 0);
+		netdev_notice(ldev->ndev, "Deactivating unsupported Option2 LED mode\n");
+	}
+
+	mode = (mode >> shift) & 0x000f;
+
+	if (mode & RTL8168_LED_CTRL_ACT)
+		*flags |= BIT(TRIGGER_NETDEV_TX) | BIT(TRIGGER_NETDEV_RX);
+
+	if (mode & RTL8168_LED_CTRL_LINK_10)
+		*flags |= BIT(TRIGGER_NETDEV_LINK_10);
+	if (mode & RTL8168_LED_CTRL_LINK_100)
+		*flags |= BIT(TRIGGER_NETDEV_LINK_100);
+	if (mode & RTL8168_LED_CTRL_LINK_1000)
+		*flags |= BIT(TRIGGER_NETDEV_LINK_1000);
+
+	return 0;
+}
+
+static struct device *
+	r8169_led_hw_control_get_device(struct led_classdev *led_cdev)
+{
+	struct r8169_led_classdev *ldev = lcdev_to_r8169_ldev(led_cdev);
+
+	return &ldev->ndev->dev;
+}
+
+static void rtl8168_setup_ldev(struct r8169_led_classdev *ldev,
+			       struct net_device *ndev, int index)
+{
+	struct rtl8169_private *tp = netdev_priv(ndev);
+	struct led_classdev *led_cdev = &ldev->led;
+	char led_name[LED_MAX_NAME_SIZE];
+
+	ldev->ndev = ndev;
+	ldev->index = index;
+
+	r8169_get_led_name(tp, index, led_name, LED_MAX_NAME_SIZE);
+	led_cdev->name = led_name;
+	led_cdev->default_trigger = "netdev";
+	led_cdev->hw_control_trigger = "netdev";
+	led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+	led_cdev->hw_control_is_supported = rtl8168_led_hw_control_is_supported;
+	led_cdev->hw_control_set = rtl8168_led_hw_control_set;
+	led_cdev->hw_control_get = rtl8168_led_hw_control_get;
+	led_cdev->hw_control_get_device = r8169_led_hw_control_get_device;
+
+	/* ignore errors */
+	devm_led_classdev_register(&ndev->dev, led_cdev);
+}
+
+void rtl8168_init_leds(struct net_device *ndev)
+{
+	/* bind resource mgmt to netdev */
+	struct device *dev = &ndev->dev;
+	struct r8169_led_classdev *leds;
+	int i;
+
+	leds = devm_kcalloc(dev, RTL8168_NUM_LEDS, sizeof(*leds), GFP_KERNEL);
+	if (!leds)
+		return;
+
+	for (i = 0; i < RTL8168_NUM_LEDS; i++)
+		rtl8168_setup_ldev(leds + i, ndev, i);
+}

drivers/net/ethernet/realtek/r8169_main.c

@@ -285,6 +285,7 @@ enum rtl8168_8101_registers {
 };
 
 enum rtl8168_registers {
+	LED_CTRL		= 0x18,
 	LED_FREQ		= 0x1a,
 	EEE_LED			= 0x1b,
 	ERIDR			= 0x70,
@@ -616,6 +617,7 @@ struct rtl8169_private {
 
 	raw_spinlock_t config25_lock;
 	raw_spinlock_t mac_ocp_lock;
+	struct mutex led_lock;	/* serialize LED ctrl RMW access */
 
 	raw_spinlock_t cfg9346_usage_lock;
 	int cfg9346_usage_count;
@@ -788,6 +790,62 @@ static const struct rtl_cond name = {			\
 							\
 static bool name ## _check(struct rtl8169_private *tp)
 
+int rtl8168_led_mod_ctrl(struct rtl8169_private *tp, u16 mask, u16 val)
+{
+	struct device *dev = tp_to_dev(tp);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&tp->led_lock);
+	RTL_W16(tp, LED_CTRL, (RTL_R16(tp, LED_CTRL) & ~mask) | val);
+	mutex_unlock(&tp->led_lock);
+
+	pm_runtime_put_sync(dev);
+
+	return 0;
+}
+
+int rtl8168_get_led_mode(struct rtl8169_private *tp)
+{
+	struct device *dev = tp_to_dev(tp);
+	int ret;
+
+	ret = pm_runtime_resume_and_get(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = RTL_R16(tp, LED_CTRL);
+
+	pm_runtime_put_sync(dev);
+
+	return ret;
+}
+
+void r8169_get_led_name(struct rtl8169_private *tp, int idx,
+			char *buf, int buf_len)
+{
+	struct pci_dev *pdev = tp->pci_dev;
+	char pdom[8], pfun[8];
+	int domain;
+
+	domain = pci_domain_nr(pdev->bus);
+	if (domain)
+		snprintf(pdom, sizeof(pdom), "P%d", domain);
+	else
+		pdom[0] = '\0';
+
+	if (pdev->multifunction)
+		snprintf(pfun, sizeof(pfun), "f%d", PCI_FUNC(pdev->devfn));
+	else
+		pfun[0] = '\0';
+
+	snprintf(buf, buf_len, "en%sp%ds%d%s-%d::lan", pdom, pdev->bus->number,
+		 PCI_SLOT(pdev->devfn), pfun, idx);
+}
+
 static void r8168fp_adjust_ocp_cmd(struct rtl8169_private *tp, u32 *cmd, int type)
 {
 	/* based on RTL8168FP_OOBMAC_BASE in vendor driver */
@@ -5141,6 +5199,7 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	raw_spin_lock_init(&tp->cfg9346_usage_lock);
 	raw_spin_lock_init(&tp->config25_lock);
 	raw_spin_lock_init(&tp->mac_ocp_lock);
+	mutex_init(&tp->led_lock);
 
 	dev->tstats = devm_netdev_alloc_pcpu_stats(&pdev->dev,
 						   struct pcpu_sw_netstats);
@@ -5297,6 +5356,12 @@ static int rtl_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (rc)
 		return rc;
 
+#if IS_REACHABLE(CONFIG_LEDS_CLASS) && IS_ENABLED(CONFIG_LEDS_TRIGGER_NETDEV)
+	if (tp->mac_version > RTL_GIGA_MAC_VER_06 &&
+	    tp->mac_version < RTL_GIGA_MAC_VER_61)
+		rtl8168_init_leds(dev);
+#endif
+
 	netdev_info(dev, "%s, %pM, XID %03x, IRQ %d\n",
 		    rtl_chip_infos[chipset].name, dev->dev_addr, xid, tp->irq);