usb: phy: add R-Car USB phy driver

This patch adds Renesas R-Car USB phy driver.
It supports R8A7779 chip at this point.

R-Car has some USB controllers, but has only one phy-initializer.
So, this driver is counting users.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/phy/Kconfig

@@ -32,3 +32,15 @@ config MV_U3D_PHY
 	help
 	  Enable this to support Marvell USB 3.0 phy controller for Marvell
 	  SoC.
+
+config USB_RCAR_PHY
+	tristate "Renesas R-Car USB phy support"
+	depends on USB || USB_GADGET
+	select USB_OTG_UTILS
+	help
+	  Say Y here to add support for the Renesas R-Car USB phy driver.
+	  This chip is typically used as USB phy for USB host, gadget.
+	  This driver supports: R8A7779
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rcar-phy.

drivers/usb/phy/Makefile

@@ -8,3 +8,4 @@ obj-$(CONFIG_OMAP_USB2)			+= omap-usb2.o
 obj-$(CONFIG_USB_ISP1301)		+= isp1301.o
 obj-$(CONFIG_MV_U3D_PHY)		+= mv_u3d_phy.o
 obj-$(CONFIG_USB_EHCI_TEGRA)	+= tegra_usb_phy.o
+obj-$(CONFIG_USB_RCAR_PHY)		+= rcar-phy.o

drivers/usb/phy/rcar-phy.c

+/*
+ * Renesas R-Car USB phy driver
+ *
+ * Copyright (C) 2012 Renesas Solutions Corp.
+ * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/usb/otg.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/module.h>
+
+/* USBH common register */
+#define USBPCTRL0	0x0800
+#define USBPCTRL1	0x0804
+#define USBST		0x0808
+#define USBEH0		0x080C
+#define USBOH0		0x081C
+#define USBCTL0		0x0858
+#define EIIBC1		0x0094
+#define EIIBC2		0x009C
+
+/* USBPCTRL1 */
+#define PHY_RST		(1 << 2)
+#define PLL_ENB		(1 << 1)
+#define PHY_ENB		(1 << 0)
+
+/* USBST */
+#define ST_ACT		(1 << 31)
+#define ST_PLL		(1 << 30)
+
+struct rcar_usb_phy_priv {
+	struct usb_phy phy;
+	spinlock_t lock;
+
+	void __iomem *reg0;
+	void __iomem *reg1;
+	int counter;
+};
+
+#define usb_phy_to_priv(p) container_of(p, struct rcar_usb_phy_priv, phy)
+
+
+/*
+ * USB initial/install operation.
+ *
+ * This function setup USB phy.
+ * The used value and setting order came from
+ * [USB :: Initial setting] on datasheet.
+ */
+static int rcar_usb_phy_init(struct usb_phy *phy)
+{
+	struct rcar_usb_phy_priv *priv = usb_phy_to_priv(phy);
+	struct device *dev = phy->dev;
+	void __iomem *reg0 = priv->reg0;
+	void __iomem *reg1 = priv->reg1;
+	int i;
+	u32 val;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+	if (priv->counter++ == 0) {
+
+		/*
+		 * USB phy start-up
+		 */
+
+		/* (1) USB-PHY standby release */
+		iowrite32(PHY_ENB, (reg0 + USBPCTRL1));
+
+		/* (2) start USB-PHY internal PLL */
+		iowrite32(PHY_ENB | PLL_ENB, (reg0 + USBPCTRL1));
+
+		/* (3) USB module status check */
+		for (i = 0; i < 1024; i++) {
+			udelay(10);
+			val = ioread32(reg0 + USBST);
+			if (val == (ST_ACT | ST_PLL))
+				break;
+		}
+
+		if (val != (ST_ACT | ST_PLL)) {
+			dev_err(dev, "USB phy not ready\n");
+			goto phy_init_end;
+		}
+
+		/* (4) USB-PHY reset clear */
+		iowrite32(PHY_ENB | PLL_ENB | PHY_RST, (reg0 + USBPCTRL1));
+
+		/* set platform specific port settings */
+		iowrite32(0x00000000, (reg0 + USBPCTRL0));
+
+		/*
+		 * EHCI IP internal buffer setting
+		 * EHCI IP internal buffer enable
+		 *
+		 * These are recommended value of a datasheet
+		 * see [USB :: EHCI internal buffer setting]
+		 */
+		iowrite32(0x00ff0040, (reg0 + EIIBC1));
+		iowrite32(0x00ff0040, (reg1 + EIIBC1));
+
+		iowrite32(0x00000001, (reg0 + EIIBC2));
+		iowrite32(0x00000001, (reg1 + EIIBC2));
+
+		/*
+		 * Bus alignment settings
+		 */
+
+		/* (1) EHCI bus alignment (little endian) */
+		iowrite32(0x00000000, (reg0 + USBEH0));
+
+		/* (1) OHCI bus alignment (little endian) */
+		iowrite32(0x00000000, (reg0 + USBOH0));
+	}
+
+phy_init_end:
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static void rcar_usb_phy_shutdown(struct usb_phy *phy)
+{
+	struct rcar_usb_phy_priv *priv = usb_phy_to_priv(phy);
+	void __iomem *reg0 = priv->reg0;
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	if (priv->counter-- == 1) { /* last user */
+		iowrite32(0x00000000, (reg0 + USBPCTRL0));
+		iowrite32(0x00000000, (reg0 + USBPCTRL1));
+	}
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static int __devinit rcar_usb_phy_probe(struct platform_device *pdev)
+{
+	struct rcar_usb_phy_priv *priv;
+	struct resource *res0, *res1;
+	struct device *dev = &pdev->dev;
+	void __iomem *reg0, *reg1;
+	int ret;
+
+	res0 = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	res1 = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	if (!res0 || !res1) {
+		dev_err(dev, "Not enough platform resources\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * CAUTION
+	 *
+	 * Because this phy address is also mapped under OHCI/EHCI address area,
+	 * this driver can't use devm_request_and_ioremap(dev, res) here
+	 */
+	reg0 = devm_ioremap_nocache(dev, res0->start, resource_size(res0));
+	reg1 = devm_ioremap_nocache(dev, res1->start, resource_size(res1));
+	if (!reg0 || !reg1) {
+		dev_err(dev, "ioremap error\n");
+		return -ENOMEM;
+	}
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv) {
+		dev_err(dev, "priv data allocation error\n");
+		return -ENOMEM;
+	}
+
+	priv->reg0		= reg0;
+	priv->reg1		= reg1;
+	priv->counter		= 0;
+	priv->phy.dev		= dev;
+	priv->phy.label		= dev_name(dev);
+	priv->phy.init		= rcar_usb_phy_init;
+	priv->phy.shutdown	= rcar_usb_phy_shutdown;
+	spin_lock_init(&priv->lock);
+
+	ret = usb_add_phy(&priv->phy, USB_PHY_TYPE_USB2);
+	if (ret < 0) {
+		dev_err(dev, "usb phy addition error\n");
+		return ret;
+	}
+
+	platform_set_drvdata(pdev, priv);
+
+	return ret;
+}
+
+static int __devexit rcar_usb_phy_remove(struct platform_device *pdev)
+{
+	struct rcar_usb_phy_priv *priv = platform_get_drvdata(pdev);
+
+	usb_remove_phy(&priv->phy);
+
+	return 0;
+}
+
+static struct platform_driver rcar_usb_phy_driver = {
+	.driver		= {
+		.name	= "rcar_usb_phy",
+	},
+	.probe		= rcar_usb_phy_probe,
+	.remove		= __devexit_p(rcar_usb_phy_remove),
+};
+
+module_platform_driver(rcar_usb_phy_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Renesas R-Car USB phy");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");