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>

4 files changed, 210 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/usb/mxs-phy.txt b/Documentation/devicetree/bindings/usb/mxs-phy.txt
new file mode 100644
index 000000000000..5835b27146ea
--- /dev/null
+++ b/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>;
+};
diff --git a/drivers/usb/otg/Kconfig b/drivers/usb/otg/Kconfig
index 5c87db06b598..13fd1ddf742f 100644
--- a/drivers/usb/otg/Kconfig
+++ b/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
diff --git a/drivers/usb/otg/Makefile b/drivers/usb/otg/Makefile
index 41aa5098b139..a844b8d35d14 100644
--- a/drivers/usb/otg/Makefile
+++ b/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
diff --git a/drivers/usb/otg/mxs-phy.c b/drivers/usb/otg/mxs-phy.c
new file mode 100644
index 000000000000..c1a67cb8e244
--- /dev/null
+++ b/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");