[PATCH v4 01/11] net: phy: Add driver for Motorcomm yt8531 gigabit ethernet phy

[Yanhong Wang <yanhong.wang@starfivetech.com>]

Add a driver for the motorcomm yt8531 gigabit ethernet phy. We have
verified the driver on StarFive VisionFive2 board.

Signed-off-by: Yanhong Wang <yanhong.wang@starfivetech.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
---
 drivers/net/phy/Kconfig     |   6 +
 drivers/net/phy/Makefile    |   1 +
 drivers/net/phy/motorcomm.c | 437 ++++++++++++++++++++++++++++++++++++
 3 files changed, 444 insertions(+)
 create mode 100644 drivers/net/phy/motorcomm.c

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index 24158776f5..0c3c39a550 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -220,6 +220,12 @@ config PHY_MICREL_KSZ8XXX
 
 endif # PHY_MICREL
 
+config PHY_MOTORCOMM
+	tristate "Motorcomm PHYs"
+	help
+	  Enables support for Motorcomm network PHYs.
+	  Currently supports the YT8531 Gigabit Ethernet PHYs.
+
 config PHY_MSCC
 	bool "Microsemi Corp Ethernet PHYs support"
 
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index 85d17f109c..2487f366e1 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_PHY_MARVELL_10G) += marvell10g.o
 obj-$(CONFIG_PHY_MICREL_KSZ8XXX) += micrel_ksz8xxx.o
 obj-$(CONFIG_PHY_MICREL_KSZ90X1) += micrel_ksz90x1.o
 obj-$(CONFIG_PHY_MESON_GXL) += meson-gxl.o
+obj-$(CONFIG_PHY_MOTORCOMM) += motorcomm.o
 obj-$(CONFIG_PHY_NATSEMI) += natsemi.o
 obj-$(CONFIG_PHY_NXP_C45_TJA11XX) += nxp-c45-tja11xx.o
 obj-$(CONFIG_PHY_NXP_TJA11XX) += nxp-tja11xx.o
diff --git a/drivers/net/phy/motorcomm.c b/drivers/net/phy/motorcomm.c
new file mode 100644
index 0000000000..e822fd76f2
--- /dev/null
+++ b/drivers/net/phy/motorcomm.c
@@ -0,0 +1,437 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Motorcomm 8531 PHY driver.
+ *
+ * Copyright (C) 2023 StarFive Technology Co., Ltd.
+ */
+
+#include <config.h>
+#include <common.h>
+#include <malloc.h>
+#include <phy.h>
+#include <linux/bitfield.h>
+
+#define PHY_ID_YT8531				0x4f51e91b
+#define PHY_ID_MASK				GENMASK(31, 0)
+
+/* Extended Register's Address Offset Register */
+#define YTPHY_PAGE_SELECT			0x1E
+
+/* Extended Register's Data Register */
+#define YTPHY_PAGE_DATA			0x1F
+
+#define YTPHY_SYNCE_CFG_REG			0xA012
+
+#define YTPHY_DTS_OUTPUT_CLK_DIS		0
+#define YTPHY_DTS_OUTPUT_CLK_25M		25000000
+#define YTPHY_DTS_OUTPUT_CLK_125M		125000000
+
+#define YT8531_SCR_SYNCE_ENABLE		BIT(6)
+/* 1b0 output 25m clock   *default*
+ * 1b1 output 125m clock
+ */
+#define YT8531_SCR_CLK_FRE_SEL_125M		BIT(4)
+#define YT8531_SCR_CLK_SRC_MASK		GENMASK(3, 1)
+#define YT8531_SCR_CLK_SRC_PLL_125M		0
+#define YT8531_SCR_CLK_SRC_UTP_RX		1
+#define YT8531_SCR_CLK_SRC_SDS_RX		2
+#define YT8531_SCR_CLK_SRC_CLOCK_FROM_DIGITAL	3
+#define YT8531_SCR_CLK_SRC_REF_25M		4
+#define YT8531_SCR_CLK_SRC_SSC_25M		5
+
+/* 1b0 use original tx_clk_rgmii  *default*
+ * 1b1 use inverted tx_clk_rgmii.
+ */
+#define YT8531_RC1R_TX_CLK_SEL_INVERTED	BIT(14)
+#define YT8531_RC1R_RX_DELAY_MASK		GENMASK(13, 10)
+#define YT8531_RC1R_FE_TX_DELAY_MASK		GENMASK(7, 4)
+#define YT8531_RC1R_GE_TX_DELAY_MASK		GENMASK(3, 0)
+#define YT8531_RC1R_RGMII_0_000_NS		0
+#define YT8531_RC1R_RGMII_0_150_NS		1
+#define YT8531_RC1R_RGMII_0_300_NS		2
+#define YT8531_RC1R_RGMII_0_450_NS		3
+#define YT8531_RC1R_RGMII_0_600_NS		4
+#define YT8531_RC1R_RGMII_0_750_NS		5
+#define YT8531_RC1R_RGMII_0_900_NS		6
+#define YT8531_RC1R_RGMII_1_050_NS		7
+#define YT8531_RC1R_RGMII_1_200_NS		8
+#define YT8531_RC1R_RGMII_1_350_NS		9
+#define YT8531_RC1R_RGMII_1_500_NS		10
+#define YT8531_RC1R_RGMII_1_650_NS		11
+#define YT8531_RC1R_RGMII_1_800_NS		12
+#define YT8531_RC1R_RGMII_1_950_NS		13
+#define YT8531_RC1R_RGMII_2_100_NS		14
+#define YT8531_RC1R_RGMII_2_250_NS		15
+
+/* Phy gmii clock gating Register */
+#define YT8531_CLOCK_GATING_REG		0xC
+#define YT8531_CGR_RX_CLK_EN			BIT(12)
+
+/* Specific Status Register */
+#define YTPHY_SPECIFIC_STATUS_REG		0x11
+#define YTPHY_DUPLEX_MASK			BIT(13)
+#define YTPHY_DUPLEX_SHIFT			13
+#define YTPHY_SPEED_MODE_MASK			GENMASK(15, 14)
+#define YTPHY_SPEED_MODE_SHIFT			14
+
+#define YT8531_EXTREG_SLEEP_CONTROL1_REG	0x27
+#define YT8531_ESC1R_SLEEP_SW			BIT(15)
+#define YT8531_ESC1R_PLLON_SLP			BIT(14)
+
+#define YT8531_RGMII_CONFIG1_REG		0xA003
+
+#define YT8531_CHIP_CONFIG_REG			0xA001
+#define YT8531_CCR_SW_RST			BIT(15)
+/* 1b0 disable 1.9ns rxc clock delay  *default*
+ * 1b1 enable 1.9ns rxc clock delay
+ */
+#define YT8531_CCR_RXC_DLY_EN			BIT(8)
+#define YT8531_CCR_RXC_DLY_1_900_NS		1900
+
+/* bits in struct ytphy_plat_priv->flag */
+#define TX_CLK_ADJ_ENABLED			BIT(0)
+#define AUTO_SLEEP_DISABLED			BIT(1)
+#define KEEP_PLL_ENABLED			BIT(2)
+#define TX_CLK_10_INVERTED			BIT(3)
+#define TX_CLK_100_INVERTED			BIT(4)
+#define TX_CLK_1000_INVERTED			BIT(5)
+
+struct ytphy_plat_priv {
+	u32 rx_delay_ps;
+	u32 tx_delay_ps;
+	u32 clk_out_frequency;
+	u32 flag;
+};
+
+/**
+ * struct ytphy_cfg_reg_map - map a config value to a register value
+ * @cfg: value in device configuration
+ * @reg: value in the register
+ */
+struct ytphy_cfg_reg_map {
+	u32 cfg;
+	u32 reg;
+};
+
+static const struct ytphy_cfg_reg_map ytphy_rgmii_delays[] = {
+	/* for tx delay / rx delay with YT8531_CCR_RXC_DLY_EN is not set. */
+	{ 0,	YT8531_RC1R_RGMII_0_000_NS },
+	{ 150,	YT8531_RC1R_RGMII_0_150_NS },
+	{ 300,	YT8531_RC1R_RGMII_0_300_NS },
+	{ 450,	YT8531_RC1R_RGMII_0_450_NS },
+	{ 600,	YT8531_RC1R_RGMII_0_600_NS },
+	{ 750,	YT8531_RC1R_RGMII_0_750_NS },
+	{ 900,	YT8531_RC1R_RGMII_0_900_NS },
+	{ 1050,	YT8531_RC1R_RGMII_1_050_NS },
+	{ 1200,	YT8531_RC1R_RGMII_1_200_NS },
+	{ 1350,	YT8531_RC1R_RGMII_1_350_NS },
+	{ 1500,	YT8531_RC1R_RGMII_1_500_NS },
+	{ 1650,	YT8531_RC1R_RGMII_1_650_NS },
+	{ 1800,	YT8531_RC1R_RGMII_1_800_NS },
+	{ 1950,	YT8531_RC1R_RGMII_1_950_NS },	/* default tx/rx delay */
+	{ 2100,	YT8531_RC1R_RGMII_2_100_NS },
+	{ 2250,	YT8531_RC1R_RGMII_2_250_NS },
+
+	/* only for rx delay with YT8531_CCR_RXC_DLY_EN is set. */
+	{ 0    + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_000_NS },
+	{ 150  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_150_NS },
+	{ 300  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_300_NS },
+	{ 450  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_450_NS },
+	{ 600  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_600_NS },
+	{ 750  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_750_NS },
+	{ 900  + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_0_900_NS },
+	{ 1050 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_050_NS },
+	{ 1200 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_200_NS },
+	{ 1350 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_350_NS },
+	{ 1500 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_500_NS },
+	{ 1650 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_650_NS },
+	{ 1800 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_800_NS },
+	{ 1950 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_1_950_NS },
+	{ 2100 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_2_100_NS },
+	{ 2250 + YT8531_CCR_RXC_DLY_1_900_NS,	YT8531_RC1R_RGMII_2_250_NS }
+};
+
+static u32 ytphy_get_delay_reg_value(struct phy_device *phydev,
+				     u32 val,
+				     u16 *rxc_dly_en)
+{
+	int tb_size = ARRAY_SIZE(ytphy_rgmii_delays);
+	int tb_size_half = tb_size / 2;
+	int i;
+
+	/* when rxc_dly_en is NULL, it is get the delay for tx, only half of
+	 * tb_size is valid.
+	 */
+	if (!rxc_dly_en)
+		tb_size = tb_size_half;
+
+	for (i = 0; i < tb_size; i++) {
+		if (ytphy_rgmii_delays[i].cfg == val) {
+			if (rxc_dly_en && i < tb_size_half)
+				*rxc_dly_en = 0;
+			return ytphy_rgmii_delays[i].reg;
+		}
+	}
+
+	pr_warn("Unsupported value %d, using default (%u)\n",
+		val, YT8531_RC1R_RGMII_1_950_NS);
+
+	/* when rxc_dly_en is not NULL, it is get the delay for rx.
+	 * The rx default in dts and ytphy_rgmii_clk_delay_config is 1950 ps,
+	 * so YT8531_CCR_RXC_DLY_EN should not be set.
+	 */
+	if (rxc_dly_en)
+		*rxc_dly_en = 0;
+
+	return YT8531_RC1R_RGMII_1_950_NS;
+}
+
+static int ytphy_modify_ext(struct phy_device *phydev, u16 regnum, u16 mask,
+			    u16 set)
+{
+	int ret;
+
+	ret = phy_write(phydev, MDIO_DEVAD_NONE, YTPHY_PAGE_SELECT, regnum);
+	if (ret < 0)
+		return ret;
+
+	return phy_modify(phydev, MDIO_DEVAD_NONE, YTPHY_PAGE_DATA, mask, set);
+}
+
+static int ytphy_rgmii_clk_delay_config(struct phy_device *phydev)
+{
+	struct ytphy_plat_priv	*priv = phydev->priv;
+	u16 rxc_dly_en = YT8531_CCR_RXC_DLY_EN;
+	u32 rx_reg, tx_reg;
+	u16 mask, val = 0;
+	int ret;
+
+	rx_reg = ytphy_get_delay_reg_value(phydev, priv->rx_delay_ps,
+					   &rxc_dly_en);
+	tx_reg = ytphy_get_delay_reg_value(phydev, priv->tx_delay_ps,
+					   NULL);
+
+	switch (phydev->interface) {
+	case PHY_INTERFACE_MODE_RGMII:
+		rxc_dly_en = 0;
+		break;
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		val |= FIELD_PREP(YT8531_RC1R_RX_DELAY_MASK, rx_reg);
+		break;
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		rxc_dly_en = 0;
+		val |= FIELD_PREP(YT8531_RC1R_GE_TX_DELAY_MASK, tx_reg);
+		break;
+	case PHY_INTERFACE_MODE_RGMII_ID:
+		val |= FIELD_PREP(YT8531_RC1R_RX_DELAY_MASK, rx_reg) |
+		       FIELD_PREP(YT8531_RC1R_GE_TX_DELAY_MASK, tx_reg);
+		break;
+	default: /* do not support other modes */
+		return -EOPNOTSUPP;
+	}
+
+	ret = ytphy_modify_ext(phydev, YT8531_CHIP_CONFIG_REG,
+			       YT8531_CCR_RXC_DLY_EN, rxc_dly_en);
+	if (ret < 0)
+		return ret;
+
+	/* Generally, it is not necessary to adjust YT8531_RC1R_FE_TX_DELAY */
+	mask = YT8531_RC1R_RX_DELAY_MASK | YT8531_RC1R_GE_TX_DELAY_MASK;
+	return ytphy_modify_ext(phydev, YT8531_RGMII_CONFIG1_REG, mask, val);
+}
+
+static int yt8531_parse_status(struct phy_device *phydev)
+{
+	int val;
+	int speed, speed_mode;
+
+	val = phy_read(phydev, MDIO_DEVAD_NONE, YTPHY_SPECIFIC_STATUS_REG);
+	if (val < 0)
+		return val;
+
+	speed_mode = (val & YTPHY_SPEED_MODE_MASK) >> YTPHY_SPEED_MODE_SHIFT;
+	switch (speed_mode) {
+	case 2:
+		speed = SPEED_1000;
+		break;
+	case 1:
+		speed = SPEED_100;
+		break;
+	default:
+		speed = SPEED_10;
+		break;
+	}
+
+	phydev->speed = speed;
+	phydev->duplex = (val & YTPHY_DUPLEX_MASK) >> YTPHY_DUPLEX_SHIFT;
+
+	return 0;
+}
+
+static int yt8531_startup(struct phy_device *phydev)
+{
+	struct ytphy_plat_priv	*priv = phydev->priv;
+	u16 val = 0;
+	int ret;
+
+	ret = genphy_update_link(phydev);
+	if (ret)
+		return ret;
+
+	ret = yt8531_parse_status(phydev);
+	if (ret)
+		return ret;
+
+	if (phydev->speed < 0)
+		return -EINVAL;
+
+	if (!(priv->flag & TX_CLK_ADJ_ENABLED))
+		return 0;
+
+	switch (phydev->speed) {
+	case SPEED_1000:
+		if (priv->flag & TX_CLK_1000_INVERTED)
+			val = YT8531_RC1R_TX_CLK_SEL_INVERTED;
+		break;
+	case SPEED_100:
+		if (priv->flag & TX_CLK_100_INVERTED)
+			val = YT8531_RC1R_TX_CLK_SEL_INVERTED;
+		break;
+	case SPEED_10:
+		if (priv->flag & TX_CLK_10_INVERTED)
+			val = YT8531_RC1R_TX_CLK_SEL_INVERTED;
+		break;
+	default:
+		printf("UNKNOWN SPEED\n");
+		return -EINVAL;
+	}
+
+	ret = ytphy_modify_ext(phydev, YT8531_RGMII_CONFIG1_REG,
+			       YT8531_RC1R_TX_CLK_SEL_INVERTED, val);
+	if (ret < 0)
+		pr_warn("Modify TX_CLK_SEL err:%d\n", ret);
+
+	return 0;
+}
+
+static void ytphy_dt_parse(struct phy_device *phydev)
+{
+	struct ytphy_plat_priv	*priv = phydev->priv;
+
+	priv->clk_out_frequency = ofnode_read_u32_default(phydev->node,
+							  "motorcomm,clk-out-frequency-hz",
+							  YTPHY_DTS_OUTPUT_CLK_DIS);
+	priv->rx_delay_ps = ofnode_read_u32_default(phydev->node,
+						    "rx-internal-delay-ps",
+						    YT8531_RC1R_RGMII_1_950_NS);
+	priv->tx_delay_ps = ofnode_read_u32_default(phydev->node,
+						    "tx-internal-delay-ps",
+						    YT8531_RC1R_RGMII_1_950_NS);
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,auto-sleep-disabled"))
+		priv->flag |= AUTO_SLEEP_DISABLED;
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,keep-pll-enabled"))
+		priv->flag |= KEEP_PLL_ENABLED;
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,tx-clk-adj-enabled"))
+		priv->flag |= TX_CLK_ADJ_ENABLED;
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,tx-clk-10-inverted"))
+		priv->flag |= TX_CLK_10_INVERTED;
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,tx-clk-100-inverted"))
+		priv->flag |= TX_CLK_100_INVERTED;
+
+	if (ofnode_read_bool(phydev->node, "motorcomm,tx-clk-1000-inverted"))
+		priv->flag |= TX_CLK_1000_INVERTED;
+}
+
+static int yt8531_config(struct phy_device *phydev)
+{
+	struct ytphy_plat_priv	*priv = phydev->priv;
+	u16 mask, val;
+	int ret;
+
+	ret = genphy_config_aneg(phydev);
+	if (ret < 0)
+		return ret;
+
+	ytphy_dt_parse(phydev);
+	switch (priv->clk_out_frequency) {
+	case YTPHY_DTS_OUTPUT_CLK_DIS:
+		mask = YT8531_SCR_SYNCE_ENABLE;
+		val = 0;
+		break;
+	case YTPHY_DTS_OUTPUT_CLK_25M:
+		mask = YT8531_SCR_SYNCE_ENABLE | YT8531_SCR_CLK_SRC_MASK |
+			   YT8531_SCR_CLK_FRE_SEL_125M;
+		val = YT8531_SCR_SYNCE_ENABLE |
+			  FIELD_PREP(YT8531_SCR_CLK_SRC_MASK,
+				     YT8531_SCR_CLK_SRC_REF_25M);
+		break;
+	case YTPHY_DTS_OUTPUT_CLK_125M:
+		mask = YT8531_SCR_SYNCE_ENABLE | YT8531_SCR_CLK_SRC_MASK |
+			   YT8531_SCR_CLK_FRE_SEL_125M;
+		val = YT8531_SCR_SYNCE_ENABLE | YT8531_SCR_CLK_FRE_SEL_125M |
+			  FIELD_PREP(YT8531_SCR_CLK_SRC_MASK,
+				     YT8531_SCR_CLK_SRC_PLL_125M);
+		break;
+	default:
+		pr_warn("Freq err:%u\n", priv->clk_out_frequency);
+		return -EINVAL;
+	}
+
+	ret = ytphy_modify_ext(phydev, YTPHY_SYNCE_CFG_REG, mask,
+			       val);
+	if (ret < 0)
+		return ret;
+
+	ret = ytphy_rgmii_clk_delay_config(phydev);
+	if (ret < 0)
+		return ret;
+
+	if (priv->flag & AUTO_SLEEP_DISABLED) {
+		/* disable auto sleep */
+		ret = ytphy_modify_ext(phydev,
+				       YT8531_EXTREG_SLEEP_CONTROL1_REG,
+				       YT8531_ESC1R_SLEEP_SW, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	if (priv->flag & KEEP_PLL_ENABLED) {
+		/* enable RXC clock when no wire plug */
+		ret = ytphy_modify_ext(phydev,
+				       YT8531_CLOCK_GATING_REG,
+				       YT8531_CGR_RX_CLK_EN, 0);
+		if (ret < 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int yt8531_probe(struct phy_device *phydev)
+{
+	struct ytphy_plat_priv	*priv;
+
+	priv = calloc(1, sizeof(struct ytphy_plat_priv));
+	if (!priv)
+		return -ENOMEM;
+
+	phydev->priv = priv;
+
+	return 0;
+}
+
+U_BOOT_PHY_DRIVER(motorcomm8531) = {
+	.name          = "YT8531 Gigabit Ethernet",
+	.uid           = PHY_ID_YT8531,
+	.mask          = PHY_ID_MASK,
+	.features      = PHY_GBIT_FEATURES,
+	.probe	       = &yt8531_probe,
+	.config        = &yt8531_config,
+	.startup       = &yt8531_startup,
+	.shutdown      = &genphy_shutdown,
+};
-- 
2.17.1