usb: otg: add basic mxs phy driver support

mxs phy is used in Freescale i.MX SoCs, for example
imx23, imx28, imx6Q. This patch adds the basic host
support.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Peter Chen <peter.chen@freescale.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Tested-by: Subodh Nijsure <snijsure@grid-net.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/devicetree/bindings/usb/mxs-phy.txt

@@ -0,0 +1,13 @@
+* Freescale MXS USB Phy Device
+
+Required properties:
+- compatible: Should be "fsl,imx23-usbphy"
+- reg: Should contain registers location and length
+- interrupts: Should contain phy interrupt
+
+Example:
+usbphy1: usbphy@020c9000 {
+	compatible = "fsl,imx6q-usbphy", "fsl,imx23-usbphy";
+	reg = <0x020c9000 0x1000>;
+	interrupts = <0 44 0x04>;
+};

drivers/usb/otg/Kconfig

@@ -116,6 +116,16 @@ config FSL_USB2_OTG
 	help
 	  Enable this to support Freescale USB OTG transceiver.
 
+config USB_MXS_PHY
+	tristate "Freescale MXS USB PHY support"
+	depends on ARCH_MXC || ARCH_MXS
+	select STMP_DEVICE
+	select USB_OTG_UTILS
+	help
+	  Enable this to support the Freescale MXS USB PHY.
+
+	  MXS Phy is used by some of the i.MX SoCs, for example imx23/28/6x.
+
 config USB_MV_OTG
 	tristate "Marvell USB OTG support"
 	depends on USB_EHCI_MV && USB_MV_UDC && USB_SUSPEND

drivers/usb/otg/Makefile

@@ -20,4 +20,5 @@ obj-$(CONFIG_USB_MSM_OTG)	+= msm_otg.o
 obj-$(CONFIG_AB8500_USB)	+= ab8500-usb.o
 fsl_usb2_otg-objs		:= fsl_otg.o otg_fsm.o
 obj-$(CONFIG_FSL_USB2_OTG)	+= fsl_usb2_otg.o
+obj-$(CONFIG_USB_MXS_PHY)	+= mxs-phy.o
 obj-$(CONFIG_USB_MV_OTG)	+= mv_otg.o

drivers/usb/otg/mxs-phy.c

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright (C) 2012 Marek Vasut <marex@denx.de>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/usb/otg.h>
+#include <linux/stmp_device.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+
+#define DRIVER_NAME "mxs_phy"
+
+#define HW_USBPHY_PWD				0x00
+#define HW_USBPHY_CTRL				0x30
+#define HW_USBPHY_CTRL_SET			0x34
+#define HW_USBPHY_CTRL_CLR			0x38
+
+#define BM_USBPHY_CTRL_SFTRST			BIT(31)
+#define BM_USBPHY_CTRL_CLKGATE			BIT(30)
+#define BM_USBPHY_CTRL_ENUTMILEVEL3		BIT(15)
+#define BM_USBPHY_CTRL_ENUTMILEVEL2		BIT(14)
+#define BM_USBPHY_CTRL_ENHOSTDISCONDETECT	BIT(1)
+
+struct mxs_phy {
+	struct usb_phy phy;
+	struct clk *clk;
+};
+
+#define to_mxs_phy(p) container_of((p), struct mxs_phy, phy)
+
+static void mxs_phy_hw_init(struct mxs_phy *mxs_phy)
+{
+	void __iomem *base = mxs_phy->phy.io_priv;
+
+	stmp_reset_block(base + HW_USBPHY_CTRL);
+
+	/* Power up the PHY */
+	writel_relaxed(0, base + HW_USBPHY_PWD);
+
+	/* enable FS/LS device */
+	writel_relaxed(BM_USBPHY_CTRL_ENUTMILEVEL2 |
+			BM_USBPHY_CTRL_ENUTMILEVEL3,
+			base + HW_USBPHY_CTRL_SET);
+}
+
+static int mxs_phy_init(struct usb_phy *phy)
+{
+	struct mxs_phy *mxs_phy = to_mxs_phy(phy);
+
+	clk_prepare_enable(mxs_phy->clk);
+	mxs_phy_hw_init(mxs_phy);
+
+	return 0;
+}
+
+static void mxs_phy_shutdown(struct usb_phy *phy)
+{
+	struct mxs_phy *mxs_phy = to_mxs_phy(phy);
+
+	writel_relaxed(BM_USBPHY_CTRL_CLKGATE,
+			phy->io_priv + HW_USBPHY_CTRL_SET);
+
+	clk_disable_unprepare(mxs_phy->clk);
+}
+
+static int mxs_phy_on_connect(struct usb_phy *phy, int port)
+{
+	dev_dbg(phy->dev, "Connect on port %d\n", port);
+
+	mxs_phy_hw_init(to_mxs_phy(phy));
+	writel_relaxed(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
+			phy->io_priv + HW_USBPHY_CTRL_SET);
+
+	return 0;
+}
+
+static int mxs_phy_on_disconnect(struct usb_phy *phy, int port)
+{
+	dev_dbg(phy->dev, "Disconnect on port %d\n", port);
+
+	writel_relaxed(BM_USBPHY_CTRL_ENHOSTDISCONDETECT,
+			phy->io_priv + HW_USBPHY_CTRL_CLR);
+
+	return 0;
+}
+
+static int mxs_phy_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	void __iomem *base;
+	struct clk *clk;
+	struct mxs_phy *mxs_phy;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		dev_err(&pdev->dev, "can't get device resources\n");
+		return -ENOENT;
+	}
+
+	base = devm_request_and_ioremap(&pdev->dev, res);
+	if (!base)
+		return -EBUSY;
+
+	clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev,
+			"can't get the clock, err=%ld", PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+
+	mxs_phy = devm_kzalloc(&pdev->dev, sizeof(*mxs_phy), GFP_KERNEL);
+	if (!mxs_phy) {
+		dev_err(&pdev->dev, "Failed to allocate USB PHY structure!\n");
+		return -ENOMEM;
+	}
+
+	mxs_phy->phy.io_priv		= base;
+	mxs_phy->phy.dev		= &pdev->dev;
+	mxs_phy->phy.label		= DRIVER_NAME;
+	mxs_phy->phy.init		= mxs_phy_init;
+	mxs_phy->phy.shutdown		= mxs_phy_shutdown;
+	mxs_phy->phy.notify_connect	= mxs_phy_on_connect;
+	mxs_phy->phy.notify_disconnect	= mxs_phy_on_disconnect;
+
+	ATOMIC_INIT_NOTIFIER_HEAD(&mxs_phy->phy.notifier);
+
+	mxs_phy->clk = clk;
+
+	platform_set_drvdata(pdev, &mxs_phy->phy);
+
+	return 0;
+}
+
+static int __devexit mxs_phy_remove(struct platform_device *pdev)
+{
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id mxs_phy_dt_ids[] = {
+	{ .compatible = "fsl,imx23-usbphy", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mxs_phy_dt_ids);
+
+static struct platform_driver mxs_phy_driver = {
+	.probe = mxs_phy_probe,
+	.remove = __devexit_p(mxs_phy_remove),
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner	= THIS_MODULE,
+		.of_match_table = mxs_phy_dt_ids,
+	 },
+};
+
+static int __init mxs_phy_module_init(void)
+{
+	return platform_driver_register(&mxs_phy_driver);
+}
+postcore_initcall(mxs_phy_module_init);
+
+static void __exit mxs_phy_module_exit(void)
+{
+	platform_driver_unregister(&mxs_phy_driver);
+}
+module_exit(mxs_phy_module_exit);
+
+MODULE_ALIAS("platform:mxs-usb-phy");
+MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
+MODULE_AUTHOR("Richard Zhao <richard.zhao@freescale.com>");
+MODULE_DESCRIPTION("Freescale MXS USB PHY driver");
+MODULE_LICENSE("GPL");