[PATCH 2/7] phy: Add driver for EyeQ5 Ethernet PHY wrapper

["Théo Lebrun" <theo.lebrun@bootlin.com>]

EyeQ5 embeds a system-controller called OLB. It features many unrelated
registers, and some of those are registers used to configure the
integration of the RGMII/SGMII Cadence PHY used by MACB/GEM instances.

Wrap in a neat generic PHY provider, exposing two PHYs with standard
phy_init() / phy_set_mode() / phy_power_on() operations.

Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 MAINTAINERS                 |   1 +
 drivers/phy/Kconfig         |  13 +++
 drivers/phy/Makefile        |   1 +
 drivers/phy/phy-eyeq5-eth.c | 254 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 269 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index ea72b3bd2248..3254717e59c6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17382,6 +17382,7 @@ F:	arch/mips/boot/dts/mobileye/
 F:	arch/mips/configs/eyeq5_defconfig
 F:	arch/mips/mobileye/board-epm5.its.S
 F:	drivers/clk/clk-eyeq.c
+F:	drivers/phy/phy-eyeq5-eth.c
 F:	drivers/pinctrl/pinctrl-eyeq5.c
 F:	drivers/reset/reset-eyeq.c
 F:	include/dt-bindings/clock/mobileye,eyeq5-clk.h
diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 678dd0452f0a..1aa6eff12dbc 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -101,6 +101,19 @@ config PHY_NXP_PTN3222
 	  schemes. It supports all three USB 2.0 data rates: Low Speed, Full
 	  Speed and High Speed.
 
+config PHY_EYEQ5_ETH
+	tristate "Ethernet PHY Driver on EyeQ5"
+	depends on OF
+	depends on MACH_EYEQ5 || COMPILE_TEST
+	select AUXILIARY_BUS
+	select GENERIC_PHY
+	default MACH_EYEQ5
+	help
+	  Enable this to support the Ethernet PHY integrated on EyeQ5.
+	  It supports both RGMII and SGMII. Registers are located in a
+	  shared register region called OLB. If M is selected, the
+	  module will be called phy-eyeq5-eth.
+
 source "drivers/phy/allwinner/Kconfig"
 source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index bfb27fb5a494..8289497ece55 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_PHY_SNPS_EUSB2)		+= phy-snps-eusb2.o
 obj-$(CONFIG_USB_LGM_PHY)		+= phy-lgm-usb.o
 obj-$(CONFIG_PHY_AIROHA_PCIE)		+= phy-airoha-pcie.o
 obj-$(CONFIG_PHY_NXP_PTN3222)		+= phy-nxp-ptn3222.o
+obj-$(CONFIG_PHY_EYEQ5_ETH)		+= phy-eyeq5-eth.o
 obj-y					+= allwinner/	\
 					   amlogic/	\
 					   broadcom/	\
diff --git a/drivers/phy/phy-eyeq5-eth.c b/drivers/phy/phy-eyeq5-eth.c
new file mode 100644
index 000000000000..b65c3d733f6c
--- /dev/null
+++ b/drivers/phy/phy-eyeq5-eth.c
@@ -0,0 +1,254 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/array_size.h>
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/bug.h>
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/lockdep.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+#include <linux/phy/phy.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define EQ5_PHY_COUNT	2
+
+#define EQ5_PHY0_GP	0x128
+#define EQ5_PHY1_GP	0x12c
+#define EQ5_PHY0_SGMII	0x134
+#define EQ5_PHY1_SGMII	0x138
+
+#define EQ5_GP_TX_SWRST_DIS	BIT(0)		// Tx SW reset
+#define EQ5_GP_TX_M_CLKE	BIT(1)		// Tx M clock enable
+#define EQ5_GP_SYS_SWRST_DIS	BIT(2)		// Sys SW reset
+#define EQ5_GP_SYS_M_CLKE	BIT(3)		// Sys clock enable
+#define EQ5_GP_SGMII_MODE	BIT(4)		// SGMII mode
+#define EQ5_GP_RGMII_DRV	GENMASK(8, 5)	// RGMII drive strength
+
+#define EQ5_SGMII_PWR_EN	BIT(0)
+#define EQ5_SGMII_RST_DIS	BIT(1)
+#define EQ5_SGMII_PLL_EN	BIT(2)
+#define EQ5_SGMII_SIG_DET_SW	BIT(3)
+#define EQ5_SGMII_PWR_STATE	BIT(4)
+#define EQ5_SGMII_PLL_ACK	BIT(18)
+#define EQ5_SGMII_PWR_STATE_ACK	GENMASK(24, 20)
+
+struct eq5_phy_inst {
+	struct eq5_phy_private	*priv;
+	struct phy		*phy;
+	void __iomem		*gp, *sgmii;
+	phy_interface_t		phy_interface;
+};
+
+struct eq5_phy_private {
+	struct device		*dev;
+	struct eq5_phy_inst	phys[EQ5_PHY_COUNT];
+};
+
+static int eq5_phy_init(struct phy *phy)
+{
+	struct eq5_phy_inst *inst = phy_get_drvdata(phy);
+	struct eq5_phy_private *priv = inst->priv;
+	struct device *dev = priv->dev;
+	u32 reg;
+
+	dev_dbg(dev, "phy_init(inst=%ld)\n", inst - priv->phys);
+
+	writel(0, inst->gp);
+	writel(0, inst->sgmii);
+
+	udelay(5);
+
+	reg = readl(inst->gp) | EQ5_GP_TX_SWRST_DIS | EQ5_GP_TX_M_CLKE |
+	      EQ5_GP_SYS_SWRST_DIS | EQ5_GP_SYS_M_CLKE |
+	      FIELD_PREP(EQ5_GP_RGMII_DRV, 0x9);
+	writel(reg, inst->gp);
+
+	return 0;
+}
+
+static int eq5_phy_exit(struct phy *phy)
+{
+	struct eq5_phy_inst *inst = phy_get_drvdata(phy);
+	struct eq5_phy_private *priv = inst->priv;
+	struct device *dev = priv->dev;
+
+	dev_dbg(dev, "phy_exit(inst=%ld)\n", inst - priv->phys);
+
+	writel(0, inst->gp);
+	writel(0, inst->sgmii);
+	udelay(5);
+
+	return 0;
+}
+
+static int eq5_phy_set_mode(struct phy *phy, enum phy_mode mode, int submode)
+{
+	struct eq5_phy_inst *inst = phy_get_drvdata(phy);
+	struct eq5_phy_private *priv = inst->priv;
+	struct device *dev = priv->dev;
+
+	dev_dbg(dev, "phy_set_mode(inst=%ld, mode=%d, submode=%d)\n",
+		inst - priv->phys, mode, submode);
+
+	if (mode != PHY_MODE_ETHERNET)
+		return -EOPNOTSUPP;
+
+	if (!phy_interface_mode_is_rgmii(submode) &&
+	    submode != PHY_INTERFACE_MODE_SGMII)
+		return -EOPNOTSUPP;
+
+	inst->phy_interface = submode;
+	return 0;
+}
+
+static int eq5_phy_power_on(struct phy *phy)
+{
+	struct eq5_phy_inst *inst = phy_get_drvdata(phy);
+	struct eq5_phy_private *priv = inst->priv;
+	struct device *dev = priv->dev;
+	u32 reg;
+
+	dev_dbg(dev, "phy_power_on(inst=%ld)\n", inst - priv->phys);
+
+	if (inst->phy_interface == PHY_INTERFACE_MODE_SGMII) {
+		writel(readl(inst->gp) | EQ5_GP_SGMII_MODE, inst->gp);
+
+		reg = EQ5_SGMII_PWR_EN | EQ5_SGMII_RST_DIS | EQ5_SGMII_PLL_EN;
+		writel(reg, inst->sgmii);
+
+		if (readl_poll_timeout(inst->sgmii, reg,
+				       reg & EQ5_SGMII_PLL_ACK, 1, 100)) {
+			dev_err(dev, "PLL timeout\n");
+			return -ETIMEDOUT;
+		}
+
+		reg = readl(inst->sgmii);
+		reg |= EQ5_SGMII_PWR_STATE | EQ5_SGMII_SIG_DET_SW;
+		writel(reg, inst->sgmii);
+	} else {
+		writel(readl(inst->gp) & ~EQ5_GP_SGMII_MODE, inst->gp);
+		writel(0, inst->sgmii);
+	}
+
+	return 0;
+}
+
+static int eq5_phy_power_off(struct phy *phy)
+{
+	struct eq5_phy_inst *inst = phy_get_drvdata(phy);
+	struct eq5_phy_private *priv = inst->priv;
+	struct device *dev = priv->dev;
+
+	dev_dbg(dev, "phy_power_off(inst=%ld)\n", inst - priv->phys);
+
+	writel(readl(inst->gp) & ~EQ5_GP_SGMII_MODE, inst->gp);
+	writel(0, inst->sgmii);
+
+	return 0;
+}
+
+static const struct phy_ops eq5_phy_ops = {
+	.init		= eq5_phy_init,
+	.exit		= eq5_phy_exit,
+	.set_mode	= eq5_phy_set_mode,
+	.power_on	= eq5_phy_power_on,
+	.power_off	= eq5_phy_power_off,
+};
+
+static struct phy *eq5_phy_xlate(struct device *dev,
+				 const struct of_phandle_args *args)
+{
+	struct eq5_phy_private *priv = dev_get_drvdata(dev);
+
+	if (args->args_count != 1 || args->args[0] > 1)
+		return ERR_PTR(-EINVAL);
+
+	return priv->phys[args->args[0]].phy;
+}
+
+static int eq5_phy_probe_phy(struct eq5_phy_private *priv, unsigned int index,
+			     void __iomem *base, unsigned int gp,
+			     unsigned int sgmii)
+{
+	struct eq5_phy_inst *inst = &priv->phys[index];
+	struct device *dev = priv->dev;
+	struct phy *phy;
+
+	phy = devm_phy_create(dev, dev->of_node, &eq5_phy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create PHY %u\n", index);
+		return PTR_ERR(phy);
+	}
+
+	inst->priv = priv;
+	inst->phy = phy;
+	inst->gp = base + gp;
+	inst->sgmii = base + sgmii;
+	inst->phy_interface = PHY_INTERFACE_MODE_NA;
+	phy_set_drvdata(phy, inst);
+
+	return 0;
+}
+
+static int eq5_phy_probe(struct auxiliary_device *adev,
+			 const struct auxiliary_device_id *id)
+{
+	struct device *dev = &adev->dev;
+	struct phy_provider *provider;
+	struct eq5_phy_private *priv;
+	void __iomem *base;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	dev_set_drvdata(dev, priv);
+
+	base = (void __iomem *)dev_get_platdata(dev);
+
+	ret = eq5_phy_probe_phy(priv, 0, base, EQ5_PHY0_GP, EQ5_PHY0_SGMII);
+	if (ret)
+		return ret;
+
+	ret = eq5_phy_probe_phy(priv, 1, base, EQ5_PHY1_GP, EQ5_PHY1_SGMII);
+	if (ret)
+		return ret;
+
+	provider = devm_of_phy_provider_register(dev, eq5_phy_xlate);
+	if (IS_ERR(provider)) {
+		dev_err(dev, "registering provider failed\n");
+		return PTR_ERR(provider);
+	}
+
+	return 0;
+}
+
+static const struct auxiliary_device_id eq5_phy_id_table[] = {
+	{ .name = "clk_eyeq.phy" },
+	{}
+};
+MODULE_DEVICE_TABLE(auxiliary, eq5_phy_id_table);
+
+static struct auxiliary_driver eq5_phy_driver = {
+	.probe = eq5_phy_probe,
+	.id_table = eq5_phy_id_table,
+};
+module_auxiliary_driver(eq5_phy_driver);
+
+MODULE_DESCRIPTION("EyeQ5 Ethernet PHY driver");
+MODULE_AUTHOR("Théo Lebrun <theo.lebrun@bootlin.com>");
+MODULE_LICENSE("GPL");

-- 
2.51.1