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>

3 files changed, 233 insertions, 0 deletions

diff --git a/drivers/usb/phy/Kconfig b/drivers/usb/phy/Kconfig
index 63c339b3e676..7eb73c561bd2 100644
--- a/drivers/usb/phy/Kconfig
+++ b/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.
diff --git a/drivers/usb/phy/Makefile b/drivers/usb/phy/Makefile
index b069f29f1225..1a579a860a03 100644
--- a/drivers/usb/phy/Makefile
+++ b/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
diff --git a/drivers/usb/phy/rcar-phy.c b/drivers/usb/phy/rcar-phy.c
new file mode 100644
index 000000000000..792f505d630c
--- /dev/null
+++ b/drivers/usb/phy/rcar-phy.c
@@ -0,0 +1,220 @@
+/*
+ * 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>");