net: phy: adin1100: Add initial support for ADIN1100 industrial PHY

The ADIN1100 is a low power single port 10BASE-T1L transceiver designed for
industrial Ethernet applications and is compliant with the IEEE 802.3cg
Ethernet standard for long reach 10 Mb/s Single Pair Ethernet.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Alexandru Tachici <alexandru.tachici@analog.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 248 insertions, 0 deletions

diff --git a/drivers/net/phy/Kconfig b/drivers/net/phy/Kconfig
index ea7571a2b39b..bbbf6c07ea53 100644
--- a/drivers/net/phy/Kconfig
+++ b/drivers/net/phy/Kconfig
@@ -83,6 +83,13 @@ config ADIN_PHY
 	  - ADIN1300 - Robust,Industrial, Low Latency 10/100/1000 Gigabit
 	    Ethernet PHY
 
+config ADIN1100_PHY
+	tristate "Analog Devices Industrial Ethernet T1L PHYs"
+	help
+	  Adds support for the Analog Devices Industrial T1L Ethernet PHYs.
+	  Currently supports the:
+	  - ADIN1100 - Robust,Industrial, Low Power 10BASE-T1L Ethernet PHY
+
 config AQUANTIA_PHY
 	tristate "Aquantia PHYs"
 	help
diff --git a/drivers/net/phy/Makefile b/drivers/net/phy/Makefile
index b2728d00fc9a..b82651b57043 100644
--- a/drivers/net/phy/Makefile
+++ b/drivers/net/phy/Makefile
@@ -31,6 +31,7 @@ sfp-obj-$(CONFIG_SFP)		+= sfp-bus.o
 obj-y				+= $(sfp-obj-y) $(sfp-obj-m)
 
 obj-$(CONFIG_ADIN_PHY)		+= adin.o
+obj-$(CONFIG_ADIN1100_PHY)	+= adin1100.o
 obj-$(CONFIG_AMD_PHY)		+= amd.o
 aquantia-objs			+= aquantia_main.o
 ifdef CONFIG_HWMON
diff --git a/drivers/net/phy/adin1100.c b/drivers/net/phy/adin1100.c
new file mode 100644
index 000000000000..f20bbef37239
--- /dev/null
+++ b/drivers/net/phy/adin1100.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
+/*
+ *  Driver for Analog Devices Industrial Ethernet T1L PHYs
+ *
+ * Copyright 2020 Analog Devices Inc.
+ */
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/phy.h>
+#include <linux/property.h>
+
+#define PHY_ID_ADIN1100				0x0283bc81
+
+#define ADIN_FORCED_MODE			0x8000
+#define   ADIN_FORCED_MODE_EN			BIT(0)
+
+#define ADIN_CRSM_SFT_RST			0x8810
+#define   ADIN_CRSM_SFT_RST_EN			BIT(0)
+
+#define ADIN_CRSM_SFT_PD_CNTRL			0x8812
+#define   ADIN_CRSM_SFT_PD_CNTRL_EN		BIT(0)
+
+#define ADIN_AN_PHY_INST_STATUS			0x8030
+#define   ADIN_IS_CFG_SLV			BIT(2)
+#define   ADIN_IS_CFG_MST			BIT(3)
+
+#define ADIN_CRSM_STAT				0x8818
+#define   ADIN_CRSM_SFT_PD_RDY			BIT(1)
+#define   ADIN_CRSM_SYS_RDY			BIT(0)
+
+/**
+ * struct adin_priv - ADIN PHY driver private data
+ * @tx_level_2v4_able:		set if the PHY supports 2.4V TX levels (10BASE-T1L)
+ * @tx_level_2v4:		set if the PHY requests 2.4V TX levels (10BASE-T1L)
+ * @tx_level_prop_present:	set if the TX level is specified in DT
+ */
+struct adin_priv {
+	unsigned int		tx_level_2v4_able:1;
+	unsigned int		tx_level_2v4:1;
+	unsigned int		tx_level_prop_present:1;
+};
+
+static int adin_read_status(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = genphy_c45_read_status(phydev);
+	if (ret)
+		return ret;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_AN, ADIN_AN_PHY_INST_STATUS);
+	if (ret < 0)
+		return ret;
+
+	if (ret & ADIN_IS_CFG_SLV)
+		phydev->master_slave_state = MASTER_SLAVE_STATE_SLAVE;
+
+	if (ret & ADIN_IS_CFG_MST)
+		phydev->master_slave_state = MASTER_SLAVE_STATE_MASTER;
+
+	return 0;
+}
+
+static int adin_config_aneg(struct phy_device *phydev)
+{
+	struct adin_priv *priv = phydev->priv;
+	int ret;
+
+	if (phydev->autoneg == AUTONEG_DISABLE) {
+		ret = genphy_c45_pma_setup_forced(phydev);
+		if (ret < 0)
+			return ret;
+
+		if (priv->tx_level_prop_present && priv->tx_level_2v4)
+			ret = phy_set_bits_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_B10L_PMA_CTRL,
+					       MDIO_PMA_10T1L_CTRL_2V4_EN);
+		else
+			ret = phy_clear_bits_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_B10L_PMA_CTRL,
+						 MDIO_PMA_10T1L_CTRL_2V4_EN);
+		if (ret < 0)
+			return ret;
+
+		/* Force PHY to use above configurations */
+		return phy_set_bits_mmd(phydev, MDIO_MMD_AN, ADIN_FORCED_MODE, ADIN_FORCED_MODE_EN);
+	}
+
+	ret = phy_clear_bits_mmd(phydev, MDIO_MMD_AN, ADIN_FORCED_MODE, ADIN_FORCED_MODE_EN);
+	if (ret < 0)
+		return ret;
+
+	/* Request increased transmit level from LP. */
+	if (priv->tx_level_prop_present && priv->tx_level_2v4) {
+		ret = phy_set_bits_mmd(phydev, MDIO_MMD_AN, MDIO_AN_T1_ADV_H,
+				       MDIO_AN_T1_ADV_H_10L_TX_HI |
+				       MDIO_AN_T1_ADV_H_10L_TX_HI_REQ);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Disable 2.4 Vpp transmit level. */
+	if ((priv->tx_level_prop_present && !priv->tx_level_2v4) || !priv->tx_level_2v4_able) {
+		ret = phy_clear_bits_mmd(phydev, MDIO_MMD_AN, MDIO_AN_T1_ADV_H,
+					 MDIO_AN_T1_ADV_H_10L_TX_HI |
+					 MDIO_AN_T1_ADV_H_10L_TX_HI_REQ);
+		if (ret < 0)
+			return ret;
+	}
+
+	return genphy_c45_config_aneg(phydev);
+}
+
+static int adin_set_powerdown_mode(struct phy_device *phydev, bool en)
+{
+	int ret;
+	int val;
+
+	val = en ? ADIN_CRSM_SFT_PD_CNTRL_EN : 0;
+	ret = phy_write_mmd(phydev, MDIO_MMD_VEND1,
+			    ADIN_CRSM_SFT_PD_CNTRL, val);
+	if (ret < 0)
+		return ret;
+
+	return phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1, ADIN_CRSM_STAT, ret,
+					 (ret & ADIN_CRSM_SFT_PD_RDY) == val,
+					 1000, 30000, true);
+}
+
+static int adin_suspend(struct phy_device *phydev)
+{
+	return adin_set_powerdown_mode(phydev, true);
+}
+
+static int adin_resume(struct phy_device *phydev)
+{
+	return adin_set_powerdown_mode(phydev, false);
+}
+
+static int adin_set_loopback(struct phy_device *phydev, bool enable)
+{
+	if (enable)
+		return phy_set_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_10T1L_CTRL,
+					BMCR_LOOPBACK);
+
+	/* PCS loopback (according to 10BASE-T1L spec) */
+	return phy_clear_bits_mmd(phydev, MDIO_MMD_PCS, MDIO_PCS_10T1L_CTRL,
+				 BMCR_LOOPBACK);
+}
+
+static int adin_soft_reset(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = phy_set_bits_mmd(phydev, MDIO_MMD_VEND1, ADIN_CRSM_SFT_RST, ADIN_CRSM_SFT_RST_EN);
+	if (ret < 0)
+		return ret;
+
+	return phy_read_mmd_poll_timeout(phydev, MDIO_MMD_VEND1, ADIN_CRSM_STAT, ret,
+					 (ret & ADIN_CRSM_SYS_RDY),
+					 10000, 30000, true);
+}
+
+static int adin_get_features(struct phy_device *phydev)
+{
+	struct adin_priv *priv = phydev->priv;
+	struct device *dev = &phydev->mdio.dev;
+	int ret;
+	u8 val;
+
+	ret = phy_read_mmd(phydev, MDIO_MMD_PMAPMD, MDIO_PMA_10T1L_STAT);
+	if (ret < 0)
+		return ret;
+
+	/* This depends on the voltage level from the power source */
+	priv->tx_level_2v4_able = !!(ret & MDIO_PMA_10T1L_STAT_2V4_ABLE);
+
+	phydev_dbg(phydev, "PHY supports 2.4V TX level: %s\n",
+		   priv->tx_level_2v4_able ? "yes" : "no");
+
+	priv->tx_level_prop_present = device_property_present(dev, "phy-10base-t1l-2.4vpp");
+	if (priv->tx_level_prop_present) {
+		ret = device_property_read_u8(dev, "phy-10base-t1l-2.4vpp", &val);
+		if (ret < 0)
+			return ret;
+
+		priv->tx_level_2v4 = val;
+		if (!priv->tx_level_2v4 && priv->tx_level_2v4_able)
+			phydev_info(phydev,
+				    "PHY supports 2.4V TX level, but disabled via config\n");
+	}
+
+	linkmode_set_bit_array(phy_basic_ports_array, ARRAY_SIZE(phy_basic_ports_array),
+			       phydev->supported);
+
+	return genphy_c45_pma_read_abilities(phydev);
+}
+
+static int adin_probe(struct phy_device *phydev)
+{
+	struct device *dev = &phydev->mdio.dev;
+	struct adin_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	phydev->priv = priv;
+
+	return 0;
+}
+
+static struct phy_driver adin_driver[] = {
+	{
+		PHY_ID_MATCH_MODEL(PHY_ID_ADIN1100),
+		.name			= "ADIN1100",
+		.get_features		= adin_get_features,
+		.soft_reset		= adin_soft_reset,
+		.probe			= adin_probe,
+		.config_aneg		= adin_config_aneg,
+		.read_status		= adin_read_status,
+		.set_loopback		= adin_set_loopback,
+		.suspend		= adin_suspend,
+		.resume			= adin_resume,
+	},
+};
+
+module_phy_driver(adin_driver);
+
+static struct mdio_device_id __maybe_unused adin_tbl[] = {
+	{ PHY_ID_MATCH_MODEL(PHY_ID_ADIN1100) },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, adin_tbl);
+MODULE_DESCRIPTION("Analog Devices Industrial Ethernet T1L PHY driver");
+MODULE_LICENSE("Dual BSD/GPL");