[PATCH net-next v5 3/3] net: phy: add DAPU Telecom DAP8211R(I) Gigabit Ethernet PHY driver

@@ -232,6 +232,15 @@ config CORTINA_PHY
 	help
 	  Currently supports the CS4340 phy.
 
+config DAP8211R_PHY
+	tristate "DAPU Telecom DAP8211R(I) Gigabit Ethernet PHY"
+	depends on OF
+	help
+	  Support for the DAPU Telecom DAP8211R(I) Gigabit Ethernet PHY.
+	  This PHY is designed for enterprise and industrial networking
+	  applications, supporting 10/100/1000 Mbps operation. Supports
+	  RGMII interface with configurable TX/RX clock delays.
+
 config DAVICOM_PHY
 	tristate "Davicom PHYs"
 	help

@@ -52,6 +52,7 @@ obj-$(CONFIG_BCM_NET_PHYPTP)	+= bcm-phy-ptp.o
 obj-$(CONFIG_BROADCOM_PHY)	+= broadcom.o
 obj-$(CONFIG_CICADA_PHY)	+= cicada.o
 obj-$(CONFIG_CORTINA_PHY)	+= cortina.o
+obj-$(CONFIG_DAP8211R_PHY)	+= dap8211r.o
 obj-$(CONFIG_DAVICOM_PHY)	+= davicom.o
 obj-$(CONFIG_DP83640_PHY)	+= dp83640.o
 obj-$(CONFIG_DP83822_PHY)	+= dp83822.o

@@ -0,0 +1,206 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the DAPU Telecom DAP8211R(I) Gigabit Ethernet PHY.
+ *
+ * Specifications:
+ *   - IEEE 802.3 10BASE-Te, 100BASE-TX, 1000BASE-T
+ *   - IEEE 802.3az-2010 Energy Efficient Ethernet
+ *   - IEEE 1588 SyncE support
+ *   - RGMII
+ *
+ * Author: Artem Shimko <a.shimko.dev@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/errno.h>
+#include <linux/ethtool.h>
+#include <linux/kernel.h>
+#include <linux/iopoll.h>
+#include <linux/mii.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/phy.h>
+
+#define DAP8211R_PHY_ID			0x0008011B
+#define DAP8211R_PHY_ID_MASK		0xFFFFFFFF
+
+#define DAP8211R_EXT_ADD		0x1E
+#define DAP8211R_EXT_DATA		0x1F
+
+#define DAP8211R_PHY_CON		0xA001
+#define DAP8211R_PHY_SW_RST		BIT(15)
+
+#define DAP8211R_RGMII_CON		0xA003
+#define DAP8211R_RGMII_TX_DEL_MASK	GENMASK(3, 0)
+#define DAP8211R_RGMII_RX_DEL_MASK	GENMASK(13, 10)
+
+#define DAP8211R_RGMII_CONFIG_MASK	(DAP8211R_RGMII_RX_DEL_MASK | DAP8211R_RGMII_TX_DEL_MASK)
+
+/* Initial RGMII RX delay per hardware specification: 0 * 150ps == 0.00ns */
+#define DAP8211R_INITIAL_RX_DEL_VAL	0
+/* Initial RGMII TX delay per hardware specification: 1 * 150ps == 0.15ns*/
+#define DAP8211R_INITIAL_TX_DEL_VAL	1
+/* Default RGMII delay: 13 * 150 == 1.95ns */
+#define DAP8211R_DEFAULT_DEL_SEL	0xD
+
+static const int dap8211r_internal_delay[] = {0, 150, 300, 450, 600, 750, 900,
+					      1050, 1200, 1350, 1500, 1650, 1800,
+					      1950, 2100, 2250};
+
+#define DAP8211R_DELAY_SIZE	ARRAY_SIZE(dap8211r_internal_delay)
+
+/**
+ * dap8211r_read_ext() - Read extended register
+ * @phydev: PHY device structure
+ * @reg: Extended register address
+ *
+ * Reads a PHY extended register using the indirect access method.
+ * The caller must hold the MDIO bus lock.
+ *
+ * Return: Register value on success, or negative error code
+ */
+static int dap8211r_read_ext(struct phy_device *phydev, u16 reg)
+{
+	int ret;
+
+	phy_lock_mdio_bus(phydev);
+	ret = __phy_write(phydev, DAP8211R_EXT_ADD, reg);
+	if (ret < 0)
+		goto out;
+
+	ret = __phy_read(phydev, DAP8211R_EXT_DATA);
+out:
+	phy_unlock_mdio_bus(phydev);
+	return ret;
+}
+
+/**
+ * dap8211r_modify_ext() - Modify extended register bits
+ * @phydev: PHY device structure
+ * @reg: Extended register address
+ * @mask: Bit mask of bits to clear
+ * @set: Bit mask of bits to set
+ *
+ * Modifies a PHY extended register using the indirect access method.
+ * New value = (old value & ~mask) | set.
+ * The caller must hold the MDIO bus lock.
+ *
+ * Return: 0 on success, or negative error code
+ */
+static int dap8211r_modify_ext(struct phy_device *phydev, u16 reg, u16 mask, u16 set)
+{
+	int ret;
+
+	phy_lock_mdio_bus(phydev);
+	ret = __phy_write(phydev, DAP8211R_EXT_ADD, reg);
+	if (ret < 0)
+		goto out;
+
+	ret = __phy_modify(phydev, DAP8211R_EXT_DATA, mask, set);
+out:
+	phy_unlock_mdio_bus(phydev);
+	return ret;
+}
+
+/**
+ * dap8211r_config_init() - Initialize PHY
+ * @phydev: PHY device structure
+ *
+ * Configures the PHY during initialization:
+ * - RGMII delays based on interface mode
+ * - Software reset to apply settings (low active, self clear)
+ *
+ * Return: 0 on success, or negative error code
+ */
+static int dap8211r_config_init(struct phy_device *phydev)
+{
+	u16 set = 0;
+	int ret, val;
+	s32 rx_internal_delay = DAP8211R_INITIAL_RX_DEL_VAL;
+	s32 tx_internal_delay = DAP8211R_INITIAL_TX_DEL_VAL;
+
+	if (!phy_interface_is_rgmii(phydev))
+		return 0;
+
+	if (phydev->interface != PHY_INTERFACE_MODE_RGMII_TXID)
+		rx_internal_delay = phy_get_internal_delay(phydev, dap8211r_internal_delay,
+							   DAP8211R_DELAY_SIZE, true);
+
+	if (phydev->interface != PHY_INTERFACE_MODE_RGMII_RXID)
+		tx_internal_delay = phy_get_internal_delay(phydev, dap8211r_internal_delay,
+							   DAP8211R_DELAY_SIZE, false);
+
+	switch (phydev->interface) {
+	case PHY_INTERFACE_MODE_RGMII:
+		if (rx_internal_delay < 0)
+			rx_internal_delay = DAP8211R_INITIAL_RX_DEL_VAL;
+
+		if (tx_internal_delay < 0)
+			tx_internal_delay = DAP8211R_INITIAL_TX_DEL_VAL;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		if (rx_internal_delay < 0)
+			rx_internal_delay = DAP8211R_DEFAULT_DEL_SEL;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		if (rx_internal_delay < 0)
+			rx_internal_delay = DAP8211R_DEFAULT_DEL_SEL;
+		fallthrough;
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		if (tx_internal_delay < 0)
+			tx_internal_delay = DAP8211R_DEFAULT_DEL_SEL;
+		break;
+	default:
+		phydev_err(phydev, "Unsupported interface: %d\n",
+			   phydev->interface);
+		return -EINVAL;
+	}
+
+	set |= FIELD_PREP(DAP8211R_RGMII_RX_DEL_MASK, rx_internal_delay);
+	set |= FIELD_PREP(DAP8211R_RGMII_TX_DEL_MASK, tx_internal_delay);
+
+	ret = dap8211r_modify_ext(phydev, DAP8211R_PHY_CON, DAP8211R_PHY_SW_RST, 0);
+	if (ret)
+		return ret;
+
+	/* Wait for reset self-clear (from low active to high) */
+	ret = read_poll_timeout(dap8211r_read_ext, val,
+				(val & DAP8211R_PHY_SW_RST),
+				20, 200, false, phydev, DAP8211R_PHY_CON);
+	if (ret)
+		return ret;
+	if (val < 0)
+		return val;
+
+	ret = dap8211r_modify_ext(phydev, DAP8211R_RGMII_CON, DAP8211R_RGMII_CONFIG_MASK, set);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static struct phy_driver dap8211r_driver[] = {
+	{
+		PHY_ID_MATCH_EXACT(DAP8211R_PHY_ID),
+		.name		= "DAP8211R Gigabit Ethernet",
+		.soft_reset	= genphy_soft_reset,
+		.config_init	= dap8211r_config_init,
+		.read_status	= genphy_read_status,
+		.set_loopback	= genphy_loopback,
+		.config_aneg	= genphy_config_aneg,
+		.suspend	= genphy_suspend,
+		.resume		= genphy_resume,
+	},
+};
+module_phy_driver(dap8211r_driver);
+
+MODULE_DESCRIPTION("DAP8211R Gigabit Ethernet PHY driver");
+MODULE_AUTHOR("Artem Shimko <a.shimko.dev@gmail.com>");
+MODULE_LICENSE("GPL");
+
+static const struct mdio_device_id __maybe_unused dap8211r_tb[] = {
+	{ DAP8211R_PHY_ID, DAP8211R_PHY_ID_MASK },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(mdio, dap8211r_tb);
+