phy: socionext: add USB3 PHY driver for UniPhier SoC

Add a driver for PHY interface built into USB3 controller
implemented in UniPhier SoCs.
This driver supports High-Speed PHY and Super-Speed PHY.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Signed-off-by: Motoya Tanigawa <tanigawa.motoya@socionext.com>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu@linaro.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

drivers/phy/Kconfig

@@ -54,6 +54,7 @@ source "drivers/phy/ralink/Kconfig"
 source "drivers/phy/renesas/Kconfig"
 source "drivers/phy/rockchip/Kconfig"
 source "drivers/phy/samsung/Kconfig"
+source "drivers/phy/socionext/Kconfig"
 source "drivers/phy/st/Kconfig"
 source "drivers/phy/tegra/Kconfig"
 source "drivers/phy/ti/Kconfig"

drivers/phy/Makefile

@@ -22,5 +22,6 @@ obj-y					+= broadcom/	\
 					   qualcomm/	\
 					   ralink/	\
 					   samsung/	\
+					   socionext/	\
 					   st/		\
 					   ti/

drivers/phy/socionext/Kconfig

+#
+# PHY drivers for Socionext platforms.
+#
+
+config PHY_UNIPHIER_USB3
+	tristate "UniPhier USB3 PHY driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support USB PHY implemented in USB3 controller
+	  on UniPhier SoCs. This controller supports USB3.0 and lower speed.

drivers/phy/socionext/Makefile

+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the phy drivers.
+#
+
+obj-$(CONFIG_PHY_UNIPHIER_USB3)	+= phy-uniphier-usb3hs.o phy-uniphier-usb3ss.o

drivers/phy/socionext/phy-uniphier-usb3ss.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * phy-uniphier-usb3ss.c - SS-PHY driver for Socionext UniPhier USB3 controller
+ * Copyright 2015-2018 Socionext Inc.
+ * Author:
+ *      Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
+ * Contributors:
+ *      Motoya Tanigawa <tanigawa.motoya@socionext.com>
+ *      Masami Hiramatsu <masami.hiramatsu@linaro.org>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#define SSPHY_TESTI		0x0
+#define SSPHY_TESTO		0x4
+#define TESTI_DAT_MASK		GENMASK(13, 6)
+#define TESTI_ADR_MASK		GENMASK(5, 1)
+#define TESTI_WR_EN		BIT(0)
+
+#define PHY_F(regno, msb, lsb) { (regno), (msb), (lsb) }
+
+#define CDR_CPD_TRIM	PHY_F(7, 3, 0)	/* RxPLL charge pump current */
+#define CDR_CPF_TRIM	PHY_F(8, 3, 0)	/* RxPLL charge pump current 2 */
+#define TX_PLL_TRIM	PHY_F(9, 3, 0)	/* TxPLL charge pump current */
+#define BGAP_TRIM	PHY_F(11, 3, 0)	/* Bandgap voltage */
+#define CDR_TRIM	PHY_F(13, 6, 5)	/* Clock Data Recovery setting */
+#define VCO_CTRL	PHY_F(26, 7, 4)	/* VCO control */
+#define VCOPLL_CTRL	PHY_F(27, 2, 0)	/* TxPLL VCO tuning */
+#define VCOPLL_CM	PHY_F(28, 1, 0)	/* TxPLL voltage */
+
+#define MAX_PHY_PARAMS	7
+
+struct uniphier_u3ssphy_param {
+	struct {
+		int reg_no;
+		int msb;
+		int lsb;
+	} field;
+	u8 value;
+};
+
+struct uniphier_u3ssphy_priv {
+	struct device *dev;
+	void __iomem *base;
+	struct clk *clk, *clk_ext, *clk_parent, *clk_parent_gio;
+	struct reset_control *rst, *rst_parent, *rst_parent_gio;
+	struct regulator *vbus;
+	const struct uniphier_u3ssphy_soc_data *data;
+};
+
+struct uniphier_u3ssphy_soc_data {
+	bool is_legacy;
+	int nparams;
+	const struct uniphier_u3ssphy_param param[MAX_PHY_PARAMS];
+};
+
+static void uniphier_u3ssphy_testio_write(struct uniphier_u3ssphy_priv *priv,
+					  u32 data)
+{
+	/* need to read TESTO twice after accessing TESTI */
+	writel(data, priv->base + SSPHY_TESTI);
+	readl(priv->base + SSPHY_TESTO);
+	readl(priv->base + SSPHY_TESTO);
+}
+
+static void uniphier_u3ssphy_set_param(struct uniphier_u3ssphy_priv *priv,
+				       const struct uniphier_u3ssphy_param *p)
+{
+	u32 val;
+	u8 field_mask = GENMASK(p->field.msb, p->field.lsb);
+	u8 data;
+
+	/* read previous data */
+	val  = FIELD_PREP(TESTI_DAT_MASK, 1);
+	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
+	uniphier_u3ssphy_testio_write(priv, val);
+	val = readl(priv->base + SSPHY_TESTO);
+
+	/* update value */
+	val &= ~FIELD_PREP(TESTI_DAT_MASK, field_mask);
+	data = field_mask & (p->value << p->field.lsb);
+	val  = FIELD_PREP(TESTI_DAT_MASK, data);
+	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
+	uniphier_u3ssphy_testio_write(priv, val);
+	uniphier_u3ssphy_testio_write(priv, val | TESTI_WR_EN);
+	uniphier_u3ssphy_testio_write(priv, val);
+
+	/* read current data as dummy */
+	val  = FIELD_PREP(TESTI_DAT_MASK, 1);
+	val |= FIELD_PREP(TESTI_ADR_MASK, p->field.reg_no);
+	uniphier_u3ssphy_testio_write(priv, val);
+	readl(priv->base + SSPHY_TESTO);
+}
+
+static int uniphier_u3ssphy_power_on(struct phy *phy)
+{
+	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
+	int ret;
+
+	ret = clk_prepare_enable(priv->clk_ext);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret)
+		goto out_clk_ext_disable;
+
+	ret = reset_control_deassert(priv->rst);
+	if (ret)
+		goto out_clk_disable;
+
+	if (priv->vbus) {
+		ret = regulator_enable(priv->vbus);
+		if (ret)
+			goto out_rst_assert;
+	}
+
+	return 0;
+
+out_rst_assert:
+	reset_control_assert(priv->rst);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk);
+out_clk_ext_disable:
+	clk_disable_unprepare(priv->clk_ext);
+
+	return ret;
+}
+
+static int uniphier_u3ssphy_power_off(struct phy *phy)
+{
+	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
+
+	if (priv->vbus)
+		regulator_disable(priv->vbus);
+
+	reset_control_assert(priv->rst);
+	clk_disable_unprepare(priv->clk);
+	clk_disable_unprepare(priv->clk_ext);
+
+	return 0;
+}
+
+static int uniphier_u3ssphy_init(struct phy *phy)
+{
+	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
+	int i, ret;
+
+	ret = clk_prepare_enable(priv->clk_parent);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(priv->clk_parent_gio);
+	if (ret)
+		goto out_clk_disable;
+
+	ret = reset_control_deassert(priv->rst_parent);
+	if (ret)
+		goto out_clk_gio_disable;
+
+	ret = reset_control_deassert(priv->rst_parent_gio);
+	if (ret)
+		goto out_rst_assert;
+
+	if (priv->data->is_legacy)
+		return 0;
+
+	for (i = 0; i < priv->data->nparams; i++)
+		uniphier_u3ssphy_set_param(priv, &priv->data->param[i]);
+
+	return 0;
+
+out_rst_assert:
+	reset_control_assert(priv->rst_parent);
+out_clk_gio_disable:
+	clk_disable_unprepare(priv->clk_parent_gio);
+out_clk_disable:
+	clk_disable_unprepare(priv->clk_parent);
+
+	return ret;
+}
+
+static int uniphier_u3ssphy_exit(struct phy *phy)
+{
+	struct uniphier_u3ssphy_priv *priv = phy_get_drvdata(phy);
+
+	reset_control_assert(priv->rst_parent_gio);
+	reset_control_assert(priv->rst_parent);
+	clk_disable_unprepare(priv->clk_parent_gio);
+	clk_disable_unprepare(priv->clk_parent);
+
+	return 0;
+}
+
+static const struct phy_ops uniphier_u3ssphy_ops = {
+	.init           = uniphier_u3ssphy_init,
+	.exit           = uniphier_u3ssphy_exit,
+	.power_on       = uniphier_u3ssphy_power_on,
+	.power_off      = uniphier_u3ssphy_power_off,
+	.owner          = THIS_MODULE,
+};
+
+static int uniphier_u3ssphy_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct uniphier_u3ssphy_priv *priv;
+	struct phy_provider *phy_provider;
+	struct resource *res;
+	struct phy *phy;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->data = of_device_get_match_data(dev);
+	if (WARN_ON(!priv->data ||
+		    priv->data->nparams > MAX_PHY_PARAMS))
+		return -EINVAL;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	if (!priv->data->is_legacy) {
+		priv->clk = devm_clk_get(dev, "phy");
+		if (IS_ERR(priv->clk))
+			return PTR_ERR(priv->clk);
+
+		priv->clk_ext = devm_clk_get(dev, "phy-ext");
+		if (IS_ERR(priv->clk_ext)) {
+			if (PTR_ERR(priv->clk_ext) == -ENOENT)
+				priv->clk_ext = NULL;
+			else
+				return PTR_ERR(priv->clk_ext);
+		}
+
+		priv->rst = devm_reset_control_get_shared(dev, "phy");
+		if (IS_ERR(priv->rst))
+			return PTR_ERR(priv->rst);
+	} else {
+		priv->clk_parent_gio = devm_clk_get(dev, "gio");
+		if (IS_ERR(priv->clk_parent_gio))
+			return PTR_ERR(priv->clk_parent_gio);
+
+		priv->rst_parent_gio =
+			devm_reset_control_get_shared(dev, "gio");
+		if (IS_ERR(priv->rst_parent_gio))
+			return PTR_ERR(priv->rst_parent_gio);
+	}
+
+	priv->clk_parent = devm_clk_get(dev, "link");
+	if (IS_ERR(priv->clk_parent))
+		return PTR_ERR(priv->clk_parent);
+
+	priv->rst_parent = devm_reset_control_get_shared(dev, "link");
+	if (IS_ERR(priv->rst_parent))
+		return PTR_ERR(priv->rst_parent);
+
+	priv->vbus = devm_regulator_get_optional(dev, "vbus");
+	if (IS_ERR(priv->vbus)) {
+		if (PTR_ERR(priv->vbus) == -EPROBE_DEFER)
+			return PTR_ERR(priv->vbus);
+		priv->vbus = NULL;
+	}
+
+	phy = devm_phy_create(dev, dev->of_node, &uniphier_u3ssphy_ops);
+	if (IS_ERR(phy))
+		return PTR_ERR(phy);
+
+	phy_set_drvdata(phy, priv);
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct uniphier_u3ssphy_soc_data uniphier_pro4_data = {
+	.is_legacy = true,
+};
+
+static const struct uniphier_u3ssphy_soc_data uniphier_pxs2_data = {
+	.is_legacy = false,
+	.nparams = 7,
+	.param = {
+		{ CDR_CPD_TRIM, 10 },
+		{ CDR_CPF_TRIM, 3 },
+		{ TX_PLL_TRIM, 5 },
+		{ BGAP_TRIM, 9 },
+		{ CDR_TRIM, 2 },
+		{ VCOPLL_CTRL, 7 },
+		{ VCOPLL_CM, 1 },
+	},
+};
+
+static const struct uniphier_u3ssphy_soc_data uniphier_ld20_data = {
+	.is_legacy = false,
+	.nparams = 3,
+	.param = {
+		{ CDR_CPD_TRIM, 6 },
+		{ CDR_TRIM, 2 },
+		{ VCO_CTRL, 5 },
+	},
+};
+
+static const struct of_device_id uniphier_u3ssphy_match[] = {
+	{
+		.compatible = "socionext,uniphier-pro4-usb3-ssphy",
+		.data = &uniphier_pro4_data,
+	},
+	{
+		.compatible = "socionext,uniphier-pxs2-usb3-ssphy",
+		.data = &uniphier_pxs2_data,
+	},
+	{
+		.compatible = "socionext,uniphier-ld20-usb3-ssphy",
+		.data = &uniphier_ld20_data,
+	},
+	{
+		.compatible = "socionext,uniphier-pxs3-usb3-ssphy",
+		.data = &uniphier_ld20_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, uniphier_u3ssphy_match);
+
+static struct platform_driver uniphier_u3ssphy_driver = {
+	.probe = uniphier_u3ssphy_probe,
+	.driver	= {
+		.name = "uniphier-usb3-ssphy",
+		.of_match_table	= uniphier_u3ssphy_match,
+	},
+};
+
+module_platform_driver(uniphier_u3ssphy_driver);
+
+MODULE_AUTHOR("Kunihiko Hayashi <hayashi.kunihiko@socionext.com>");
+MODULE_DESCRIPTION("UniPhier SS-PHY driver for USB3 controller");
+MODULE_LICENSE("GPL v2");