phy: add driver for Freescale i.MX8MQ USB3 PHY

This is a cleaned up port of the downstream i.MX8MQ USB3 PHY driver.

Signed-off-by: Li Jun <[e-mail]>
Signed-off-by: Lucas Stach <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

drivers/phy/Kconfig

···
 source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
 source "drivers/phy/cadence/Kconfig"
+source "drivers/phy/freescale/Kconfig"
 source "drivers/phy/hisilicon/Kconfig"
 source "drivers/phy/lantiq/Kconfig"
 source "drivers/phy/marvell/Kconfig"

drivers/phy/Makefile

···
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-y					+= broadcom/	\
 					   cadence/	\
+					   freescale/	\
 					   hisilicon/	\
 					   marvell/	\
 					   motorola/	\

drivers/phy/freescale/Kconfig

···
+config PHY_FSL_IMX8MQ_USB
+	tristate "Freescale i.MX8M USB3 PHY"
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	default SOC_IMX8MQ

drivers/phy/freescale/Makefile

···
+obj-$(CONFIG_PHY_FSL_IMX8MQ_USB)	+= phy-fsl-imx8mq-usb.o

drivers/phy/freescale/phy-fsl-imx8mq-usb.c

···
+// SPDX-License-Identifier: GPL-2.0+
+/* Copyright (c) 2017 NXP. */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+#define PHY_CTRL0			0x0
+#define PHY_CTRL0_REF_SSP_EN		BIT(2)
+
+#define PHY_CTRL1			0x4
+#define PHY_CTRL1_RESET			BIT(0)
+#define PHY_CTRL1_COMMONONN		BIT(1)
+#define PHY_CTRL1_ATERESET		BIT(3)
+#define PHY_CTRL1_VDATSRCENB0		BIT(19)
+#define PHY_CTRL1_VDATDETENB0		BIT(20)
+
+#define PHY_CTRL2			0x8
+#define PHY_CTRL2_TXENABLEN0		BIT(8)
+
+struct imx8mq_usb_phy {
+	struct phy *phy;
+	struct clk *clk;
+	void __iomem *base;
+};
+
+static int imx8mq_usb_phy_init(struct phy *phy)
+{
+	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
+	u32 value;
+
+	value = readl(imx_phy->base + PHY_CTRL1);
+	value &= ~(PHY_CTRL1_VDATSRCENB0 | PHY_CTRL1_VDATDETENB0 |
+		   PHY_CTRL1_COMMONONN);
+	value |= PHY_CTRL1_RESET | PHY_CTRL1_ATERESET;
+	writel(value, imx_phy->base + PHY_CTRL1);
+
+	value = readl(imx_phy->base + PHY_CTRL0);
+	value |= PHY_CTRL0_REF_SSP_EN;
+	writel(value, imx_phy->base + PHY_CTRL0);
+
+	value = readl(imx_phy->base + PHY_CTRL2);
+	value |= PHY_CTRL2_TXENABLEN0;
+	writel(value, imx_phy->base + PHY_CTRL2);
+
+	value = readl(imx_phy->base + PHY_CTRL1);
+	value &= ~(PHY_CTRL1_RESET | PHY_CTRL1_ATERESET);
+	writel(value, imx_phy->base + PHY_CTRL1);
+
+	return 0;
+}
+
+static int imx8mq_phy_power_on(struct phy *phy)
+{
+	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
+
+	return clk_prepare_enable(imx_phy->clk);
+}
+
+static int imx8mq_phy_power_off(struct phy *phy)
+{
+	struct imx8mq_usb_phy *imx_phy = phy_get_drvdata(phy);
+
+	clk_disable_unprepare(imx_phy->clk);
+
+	return 0;
+}
+
+static struct phy_ops imx8mq_usb_phy_ops = {
+	.init		= imx8mq_usb_phy_init,
+	.power_on	= imx8mq_phy_power_on,
+	.power_off	= imx8mq_phy_power_off,
+	.owner		= THIS_MODULE,
+};
+
+static int imx8mq_usb_phy_probe(struct platform_device *pdev)
+{
+	struct phy_provider *phy_provider;
+	struct device *dev = &pdev->dev;
+	struct imx8mq_usb_phy *imx_phy;
+	struct resource *res;
+
+	imx_phy = devm_kzalloc(dev, sizeof(*imx_phy), GFP_KERNEL);
+	if (!imx_phy)
+		return -ENOMEM;
+
+	imx_phy->clk = devm_clk_get(dev, "phy");
+	if (IS_ERR(imx_phy->clk)) {
+		dev_err(dev, "failed to get imx8mq usb phy clock\n");
+		return PTR_ERR(imx_phy->clk);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	imx_phy->base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(imx_phy->base))
+		return PTR_ERR(imx_phy->base);
+
+	imx_phy->phy = devm_phy_create(dev, NULL, &imx8mq_usb_phy_ops);
+	if (IS_ERR(imx_phy->phy))
+		return PTR_ERR(imx_phy->phy);
+
+	phy_set_drvdata(imx_phy->phy, imx_phy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id imx8mq_usb_phy_of_match[] = {
+	{.compatible = "fsl,imx8mq-usb-phy",},
+	{ },
+};
+MODULE_DEVICE_TABLE(of, imx8mq_usb_phy_of_match);
+
+static struct platform_driver imx8mq_usb_phy_driver = {
+	.probe	= imx8mq_usb_phy_probe,
+	.driver = {
+		.name	= "imx8mq-usb-phy",
+		.of_match_table	= imx8mq_usb_phy_of_match,
+	}
+};
+module_platform_driver(imx8mq_usb_phy_driver);
+
+MODULE_DESCRIPTION("FSL IMX8MQ USB PHY driver");
+MODULE_LICENSE("GPL");