mfd: omap-usb-tll: HOST TLL platform driver
authorKeshava Munegowda <keshava_mgowda@ti.com>
Mon, 16 Jul 2012 13:31:08 +0000 (19:01 +0530)
committerSamuel Ortiz <sameo@linux.intel.com>
Fri, 21 Sep 2012 21:39:24 +0000 (23:39 +0200)
The platform driver for the TLL component of the OMAP USB host controller
is implemented. Depending on the TLL hardware revision , the TLL channels
are configured. The USB HS core driver uses this driver through exported
APIs from the TLL platform driver.
usb_tll_enable and usb_tll_disble are the exported APIs of the USB TLL
platform driver.

Signed-off-by: Keshava Munegowda <keshava_mgowda@ti.com>
Reviewed-by: Partha Basak <parthab@india.ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
arch/arm/plat-omap/include/plat/usb.h
drivers/mfd/Kconfig
drivers/mfd/Makefile
drivers/mfd/omap-usb-tll.c [new file with mode: 0644]

index 548a4c8..ca15a26 100644 (file)
@@ -64,6 +64,10 @@ struct usbhs_omap_platform_data {
        struct ehci_hcd_omap_platform_data      *ehci_data;
        struct ohci_hcd_omap_platform_data      *ohci_data;
 };
+
+struct usbtll_omap_platform_data {
+       enum usbhs_omap_port_mode               port_mode[OMAP3_HS_USB_PORTS];
+};
 /*-------------------------------------------------------------------------*/
 
 struct omap_musb_board_data {
@@ -82,6 +86,8 @@ enum musb_interface    {MUSB_INTERFACE_ULPI, MUSB_INTERFACE_UTMI};
 extern void usb_musb_init(struct omap_musb_board_data *board_data);
 
 extern void usbhs_init(const struct usbhs_omap_board_data *pdata);
+extern int omap_tll_enable(void);
+extern int omap_tll_disable(void);
 
 extern int omap4430_phy_power(struct device *dev, int ID, int on);
 extern int omap4430_phy_set_clk(struct device *dev, int on);
index 2143fd2..b9282ca 100644 (file)
@@ -897,7 +897,7 @@ config MFD_WL1273_CORE
          audio codec.
 
 config MFD_OMAP_USB_HOST
-       bool "Support OMAP USBHS core driver"
+       bool "Support OMAP USBHS core and TLL driver"
        depends on USB_EHCI_HCD_OMAP || USB_OHCI_HCD_OMAP3
        default y
        help
index 95dfa14..d16bc02 100644 (file)
@@ -120,7 +120,7 @@ obj-$(CONFIG_MFD_TPS6586X)  += tps6586x.o
 obj-$(CONFIG_MFD_VX855)                += vx855.o
 obj-$(CONFIG_MFD_WL1273_CORE)  += wl1273-core.o
 obj-$(CONFIG_MFD_CS5535)       += cs5535-mfd.o
-obj-$(CONFIG_MFD_OMAP_USB_HOST)        += omap-usb-host.o
+obj-$(CONFIG_MFD_OMAP_USB_HOST)        += omap-usb-host.o omap-usb-tll.o
 obj-$(CONFIG_MFD_PM8921_CORE)  += pm8921-core.o
 obj-$(CONFIG_MFD_PM8XXX_IRQ)   += pm8xxx-irq.o
 obj-$(CONFIG_TPS65911_COMPARATOR)      += tps65911-comparator.o
diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
new file mode 100644 (file)
index 0000000..4b7757b
--- /dev/null
@@ -0,0 +1,471 @@
+/**
+ * omap-usb-tll.c - The USB TLL driver for OMAP EHCI & OHCI
+ *
+ * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Keshava Munegowda <keshava_mgowda@ti.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  of
+ * the License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <plat/usb.h>
+#include <linux/pm_runtime.h>
+
+#define USBTLL_DRIVER_NAME     "usbhs_tll"
+
+/* TLL Register Set */
+#define        OMAP_USBTLL_REVISION                            (0x00)
+#define        OMAP_USBTLL_SYSCONFIG                           (0x10)
+#define        OMAP_USBTLL_SYSCONFIG_CACTIVITY                 (1 << 8)
+#define        OMAP_USBTLL_SYSCONFIG_SIDLEMODE                 (1 << 3)
+#define        OMAP_USBTLL_SYSCONFIG_ENAWAKEUP                 (1 << 2)
+#define        OMAP_USBTLL_SYSCONFIG_SOFTRESET                 (1 << 1)
+#define        OMAP_USBTLL_SYSCONFIG_AUTOIDLE                  (1 << 0)
+
+#define        OMAP_USBTLL_SYSSTATUS                           (0x14)
+#define        OMAP_USBTLL_SYSSTATUS_RESETDONE                 (1 << 0)
+
+#define        OMAP_USBTLL_IRQSTATUS                           (0x18)
+#define        OMAP_USBTLL_IRQENABLE                           (0x1C)
+
+#define        OMAP_TLL_SHARED_CONF                            (0x30)
+#define        OMAP_TLL_SHARED_CONF_USB_90D_DDR_EN             (1 << 6)
+#define        OMAP_TLL_SHARED_CONF_USB_180D_SDR_EN            (1 << 5)
+#define        OMAP_TLL_SHARED_CONF_USB_DIVRATION              (1 << 2)
+#define        OMAP_TLL_SHARED_CONF_FCLK_REQ                   (1 << 1)
+#define        OMAP_TLL_SHARED_CONF_FCLK_IS_ON                 (1 << 0)
+
+#define        OMAP_TLL_CHANNEL_CONF(num)                      (0x040 + 0x004 * num)
+#define OMAP_TLL_CHANNEL_CONF_FSLSMODE_SHIFT           24
+#define        OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF            (1 << 11)
+#define        OMAP_TLL_CHANNEL_CONF_ULPI_ULPIAUTOIDLE         (1 << 10)
+#define        OMAP_TLL_CHANNEL_CONF_UTMIAUTOIDLE              (1 << 9)
+#define        OMAP_TLL_CHANNEL_CONF_ULPIDDRMODE               (1 << 8)
+#define OMAP_TLL_CHANNEL_CONF_CHANMODE_FSLS            (1 << 1)
+#define        OMAP_TLL_CHANNEL_CONF_CHANEN                    (1 << 0)
+
+#define OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0             0x0
+#define OMAP_TLL_FSLSMODE_6PIN_PHY_DP_DM               0x1
+#define OMAP_TLL_FSLSMODE_3PIN_PHY                     0x2
+#define OMAP_TLL_FSLSMODE_4PIN_PHY                     0x3
+#define OMAP_TLL_FSLSMODE_6PIN_TLL_DAT_SE0             0x4
+#define OMAP_TLL_FSLSMODE_6PIN_TLL_DP_DM               0x5
+#define OMAP_TLL_FSLSMODE_3PIN_TLL                     0x6
+#define OMAP_TLL_FSLSMODE_4PIN_TLL                     0x7
+#define OMAP_TLL_FSLSMODE_2PIN_TLL_DAT_SE0             0xA
+#define OMAP_TLL_FSLSMODE_2PIN_DAT_DP_DM               0xB
+
+#define        OMAP_TLL_ULPI_FUNCTION_CTRL(num)                (0x804 + 0x100 * num)
+#define        OMAP_TLL_ULPI_INTERFACE_CTRL(num)               (0x807 + 0x100 * num)
+#define        OMAP_TLL_ULPI_OTG_CTRL(num)                     (0x80A + 0x100 * num)
+#define        OMAP_TLL_ULPI_INT_EN_RISE(num)                  (0x80D + 0x100 * num)
+#define        OMAP_TLL_ULPI_INT_EN_FALL(num)                  (0x810 + 0x100 * num)
+#define        OMAP_TLL_ULPI_INT_STATUS(num)                   (0x813 + 0x100 * num)
+#define        OMAP_TLL_ULPI_INT_LATCH(num)                    (0x814 + 0x100 * num)
+#define        OMAP_TLL_ULPI_DEBUG(num)                        (0x815 + 0x100 * num)
+#define        OMAP_TLL_ULPI_SCRATCH_REGISTER(num)             (0x816 + 0x100 * num)
+
+#define OMAP_REV2_TLL_CHANNEL_COUNT                    2
+#define OMAP_TLL_CHANNEL_COUNT                         3
+#define OMAP_TLL_CHANNEL_1_EN_MASK                     (1 << 0)
+#define OMAP_TLL_CHANNEL_2_EN_MASK                     (1 << 1)
+#define OMAP_TLL_CHANNEL_3_EN_MASK                     (1 << 2)
+
+/* Values of USBTLL_REVISION - Note: these are not given in the TRM */
+#define OMAP_USBTLL_REV1               0x00000015      /* OMAP3 */
+#define OMAP_USBTLL_REV2               0x00000018      /* OMAP 3630 */
+#define OMAP_USBTLL_REV3               0x00000004      /* OMAP4 */
+
+#define is_ehci_tll_mode(x)    (x == OMAP_EHCI_PORT_MODE_TLL)
+
+struct usbtll_omap {
+       struct clk                              *usbtll_p1_fck;
+       struct clk                              *usbtll_p2_fck;
+       struct usbtll_omap_platform_data        platdata;
+       /* secure the register updates */
+       spinlock_t                              lock;
+};
+
+/*-------------------------------------------------------------------------*/
+
+const char usbtll_driver_name[] = USBTLL_DRIVER_NAME;
+struct platform_device *tll_pdev;
+
+/*-------------------------------------------------------------------------*/
+
+static inline void usbtll_write(void __iomem *base, u32 reg, u32 val)
+{
+       __raw_writel(val, base + reg);
+}
+
+static inline u32 usbtll_read(void __iomem *base, u32 reg)
+{
+       return __raw_readl(base + reg);
+}
+
+static inline void usbtll_writeb(void __iomem *base, u8 reg, u8 val)
+{
+       __raw_writeb(val, base + reg);
+}
+
+static inline u8 usbtll_readb(void __iomem *base, u8 reg)
+{
+       return __raw_readb(base + reg);
+}
+
+/*-------------------------------------------------------------------------*/
+
+static bool is_ohci_port(enum usbhs_omap_port_mode pmode)
+{
+       switch (pmode) {
+       case OMAP_OHCI_PORT_MODE_PHY_6PIN_DATSE0:
+       case OMAP_OHCI_PORT_MODE_PHY_6PIN_DPDM:
+       case OMAP_OHCI_PORT_MODE_PHY_3PIN_DATSE0:
+       case OMAP_OHCI_PORT_MODE_PHY_4PIN_DPDM:
+       case OMAP_OHCI_PORT_MODE_TLL_6PIN_DATSE0:
+       case OMAP_OHCI_PORT_MODE_TLL_6PIN_DPDM:
+       case OMAP_OHCI_PORT_MODE_TLL_3PIN_DATSE0:
+       case OMAP_OHCI_PORT_MODE_TLL_4PIN_DPDM:
+       case OMAP_OHCI_PORT_MODE_TLL_2PIN_DATSE0:
+       case OMAP_OHCI_PORT_MODE_TLL_2PIN_DPDM:
+               return true;
+
+       default:
+               return false;
+       }
+}
+
+/*
+ * convert the port-mode enum to a value we can use in the FSLSMODE
+ * field of USBTLL_CHANNEL_CONF
+ */
+static unsigned ohci_omap3_fslsmode(enum usbhs_omap_port_mode mode)
+{
+       switch (mode) {
+       case OMAP_USBHS_PORT_MODE_UNUSED:
+       case OMAP_OHCI_PORT_MODE_PHY_6PIN_DATSE0:
+               return OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0;
+
+       case OMAP_OHCI_PORT_MODE_PHY_6PIN_DPDM:
+               return OMAP_TLL_FSLSMODE_6PIN_PHY_DP_DM;
+
+       case OMAP_OHCI_PORT_MODE_PHY_3PIN_DATSE0:
+               return OMAP_TLL_FSLSMODE_3PIN_PHY;
+
+       case OMAP_OHCI_PORT_MODE_PHY_4PIN_DPDM:
+               return OMAP_TLL_FSLSMODE_4PIN_PHY;
+
+       case OMAP_OHCI_PORT_MODE_TLL_6PIN_DATSE0:
+               return OMAP_TLL_FSLSMODE_6PIN_TLL_DAT_SE0;
+
+       case OMAP_OHCI_PORT_MODE_TLL_6PIN_DPDM:
+               return OMAP_TLL_FSLSMODE_6PIN_TLL_DP_DM;
+
+       case OMAP_OHCI_PORT_MODE_TLL_3PIN_DATSE0:
+               return OMAP_TLL_FSLSMODE_3PIN_TLL;
+
+       case OMAP_OHCI_PORT_MODE_TLL_4PIN_DPDM:
+               return OMAP_TLL_FSLSMODE_4PIN_TLL;
+
+       case OMAP_OHCI_PORT_MODE_TLL_2PIN_DATSE0:
+               return OMAP_TLL_FSLSMODE_2PIN_TLL_DAT_SE0;
+
+       case OMAP_OHCI_PORT_MODE_TLL_2PIN_DPDM:
+               return OMAP_TLL_FSLSMODE_2PIN_DAT_DP_DM;
+       default:
+               pr_warn("Invalid port mode, using default\n");
+               return OMAP_TLL_FSLSMODE_6PIN_PHY_DAT_SE0;
+       }
+}
+
+/**
+ * usbtll_omap_probe - initialize TI-based HCDs
+ *
+ * Allocates basic resources for this USB host controller.
+ */
+static int __devinit usbtll_omap_probe(struct platform_device *pdev)
+{
+       struct device                           *dev =  &pdev->dev;
+       struct usbtll_omap_platform_data        *pdata = dev->platform_data;
+       void __iomem                            *base;
+       struct resource                         *res;
+       struct usbtll_omap                      *tll;
+       unsigned                                reg;
+       unsigned long                           flags;
+       int                                     ret = 0;
+       int                                     i, ver, count;
+
+       dev_dbg(dev, "starting TI HSUSB TLL Controller\n");
+
+       tll = kzalloc(sizeof(struct usbtll_omap), GFP_KERNEL);
+       if (!tll) {
+               dev_err(dev, "Memory allocation failed\n");
+               ret = -ENOMEM;
+               goto end;
+       }
+
+       spin_lock_init(&tll->lock);
+
+       for (i = 0; i < OMAP3_HS_USB_PORTS; i++)
+               tll->platdata.port_mode[i] = pdata->port_mode[i];
+
+       tll->usbtll_p1_fck = clk_get(dev, "usb_tll_hs_usb_ch0_clk");
+       if (IS_ERR(tll->usbtll_p1_fck)) {
+               ret = PTR_ERR(tll->usbtll_p1_fck);
+               dev_err(dev, "usbtll_p1_fck failed error:%d\n", ret);
+               goto err_tll;
+       }
+
+       tll->usbtll_p2_fck = clk_get(dev, "usb_tll_hs_usb_ch1_clk");
+       if (IS_ERR(tll->usbtll_p2_fck)) {
+               ret = PTR_ERR(tll->usbtll_p2_fck);
+               dev_err(dev, "usbtll_p2_fck failed error:%d\n", ret);
+               goto err_usbtll_p1_fck;
+       }
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!res) {
+               dev_err(dev, "usb tll get resource failed\n");
+               ret = -ENODEV;
+               goto err_usbtll_p2_fck;
+       }
+
+       base = ioremap(res->start, resource_size(res));
+       if (!base) {
+               dev_err(dev, "TLL ioremap failed\n");
+               ret = -ENOMEM;
+               goto err_usbtll_p2_fck;
+       }
+
+       platform_set_drvdata(pdev, tll);
+       pm_runtime_enable(dev);
+       pm_runtime_get_sync(dev);
+
+       spin_lock_irqsave(&tll->lock, flags);
+
+       ver =  usbtll_read(base, OMAP_USBTLL_REVISION);
+       switch (ver) {
+       case OMAP_USBTLL_REV1:
+       case OMAP_USBTLL_REV2:
+               count = OMAP_TLL_CHANNEL_COUNT;
+               break;
+       case OMAP_USBTLL_REV3:
+               count = OMAP_REV2_TLL_CHANNEL_COUNT;
+               break;
+       default:
+               dev_err(dev, "TLL version failed\n");
+               ret = -ENODEV;
+               goto err_ioremap;
+       }
+
+       if (is_ehci_tll_mode(pdata->port_mode[0]) ||
+           is_ehci_tll_mode(pdata->port_mode[1]) ||
+           is_ehci_tll_mode(pdata->port_mode[2]) ||
+           is_ohci_port(pdata->port_mode[0]) ||
+           is_ohci_port(pdata->port_mode[1]) ||
+           is_ohci_port(pdata->port_mode[2])) {
+
+               /* Program Common TLL register */
+               reg = usbtll_read(base, OMAP_TLL_SHARED_CONF);
+               reg |= (OMAP_TLL_SHARED_CONF_FCLK_IS_ON
+                       | OMAP_TLL_SHARED_CONF_USB_DIVRATION);
+               reg &= ~OMAP_TLL_SHARED_CONF_USB_90D_DDR_EN;
+               reg &= ~OMAP_TLL_SHARED_CONF_USB_180D_SDR_EN;
+
+               usbtll_write(base, OMAP_TLL_SHARED_CONF, reg);
+
+               /* Enable channels now */
+               for (i = 0; i < count; i++) {
+                       reg = usbtll_read(base, OMAP_TLL_CHANNEL_CONF(i));
+
+                       if (is_ohci_port(pdata->port_mode[i])) {
+                               reg |= ohci_omap3_fslsmode(pdata->port_mode[i])
+                               << OMAP_TLL_CHANNEL_CONF_FSLSMODE_SHIFT;
+                               reg |= OMAP_TLL_CHANNEL_CONF_CHANMODE_FSLS;
+                       } else if (pdata->port_mode[i] ==
+                                       OMAP_EHCI_PORT_MODE_TLL) {
+                               /*
+                                * Disable AutoIdle, BitStuffing
+                                * and use SDR Mode
+                                */
+                               reg &= ~(OMAP_TLL_CHANNEL_CONF_UTMIAUTOIDLE
+                                       | OMAP_TLL_CHANNEL_CONF_ULPINOBITSTUFF
+                                       | OMAP_TLL_CHANNEL_CONF_ULPIDDRMODE);
+                       } else {
+                               continue;
+                       }
+                       reg |= OMAP_TLL_CHANNEL_CONF_CHANEN;
+                       usbtll_write(base, OMAP_TLL_CHANNEL_CONF(i), reg);
+
+                       usbtll_writeb(base,
+                                     OMAP_TLL_ULPI_SCRATCH_REGISTER(i),
+                                     0xbe);
+               }
+       }
+
+err_ioremap:
+       spin_unlock_irqrestore(&tll->lock, flags);
+       iounmap(base);
+       pm_runtime_put_sync(dev);
+       tll_pdev = pdev;
+       if (!ret)
+               goto end;
+       pm_runtime_disable(dev);
+
+err_usbtll_p2_fck:
+       clk_put(tll->usbtll_p2_fck);
+
+err_usbtll_p1_fck:
+       clk_put(tll->usbtll_p1_fck);
+
+err_tll:
+       kfree(tll);
+
+end:
+       return ret;
+}
+
+/**
+ * usbtll_omap_remove - shutdown processing for UHH & TLL HCDs
+ * @pdev: USB Host Controller being removed
+ *
+ * Reverses the effect of usbtll_omap_probe().
+ */
+static int __devexit usbtll_omap_remove(struct platform_device *pdev)
+{
+       struct usbtll_omap *tll = platform_get_drvdata(pdev);
+
+       clk_put(tll->usbtll_p2_fck);
+       clk_put(tll->usbtll_p1_fck);
+       pm_runtime_disable(&pdev->dev);
+       kfree(tll);
+       return 0;
+}
+
+static int usbtll_runtime_resume(struct device *dev)
+{
+       struct usbtll_omap                      *tll = dev_get_drvdata(dev);
+       struct usbtll_omap_platform_data        *pdata = &tll->platdata;
+       unsigned long                           flags;
+
+       dev_dbg(dev, "usbtll_runtime_resume\n");
+
+       if (!pdata) {
+               dev_dbg(dev, "missing platform_data\n");
+               return  -ENODEV;
+       }
+
+       spin_lock_irqsave(&tll->lock, flags);
+
+       if (is_ehci_tll_mode(pdata->port_mode[0]))
+               clk_enable(tll->usbtll_p1_fck);
+
+       if (is_ehci_tll_mode(pdata->port_mode[1]))
+               clk_enable(tll->usbtll_p2_fck);
+
+       spin_unlock_irqrestore(&tll->lock, flags);
+
+       return 0;
+}
+
+static int usbtll_runtime_suspend(struct device *dev)
+{
+       struct usbtll_omap                      *tll = dev_get_drvdata(dev);
+       struct usbtll_omap_platform_data        *pdata = &tll->platdata;
+       unsigned long                           flags;
+
+       dev_dbg(dev, "usbtll_runtime_suspend\n");
+
+       if (!pdata) {
+               dev_dbg(dev, "missing platform_data\n");
+               return  -ENODEV;
+       }
+
+       spin_lock_irqsave(&tll->lock, flags);
+
+       if (is_ehci_tll_mode(pdata->port_mode[0]))
+               clk_disable(tll->usbtll_p1_fck);
+
+       if (is_ehci_tll_mode(pdata->port_mode[1]))
+               clk_disable(tll->usbtll_p2_fck);
+
+       spin_unlock_irqrestore(&tll->lock, flags);
+
+       return 0;
+}
+
+static const struct dev_pm_ops usbtllomap_dev_pm_ops = {
+       SET_RUNTIME_PM_OPS(usbtll_runtime_suspend,
+                          usbtll_runtime_resume,
+                          NULL)
+};
+
+static struct platform_driver usbtll_omap_driver = {
+       .driver = {
+               .name           = (char *)usbtll_driver_name,
+               .owner          = THIS_MODULE,
+               .pm             = &usbtllomap_dev_pm_ops,
+       },
+       .probe          = usbtll_omap_probe,
+       .remove         = __devexit_p(usbtll_omap_remove),
+};
+
+int omap_tll_enable(void)
+{
+       if (!tll_pdev) {
+               pr_err("missing omap usbhs tll platform_data\n");
+               return  -ENODEV;
+       }
+       return pm_runtime_get_sync(&tll_pdev->dev);
+}
+EXPORT_SYMBOL_GPL(omap_tll_enable);
+
+int omap_tll_disable(void)
+{
+       if (!tll_pdev) {
+               pr_err("missing omap usbhs tll platform_data\n");
+               return  -ENODEV;
+       }
+       return pm_runtime_put_sync(&tll_pdev->dev);
+}
+EXPORT_SYMBOL_GPL(omap_tll_disable);
+
+MODULE_AUTHOR("Keshava Munegowda <keshava_mgowda@ti.com>");
+MODULE_ALIAS("platform:" USBHS_DRIVER_NAME);
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("usb tll driver for TI OMAP EHCI and OHCI controllers");
+
+static int __init omap_usbtll_drvinit(void)
+{
+       return platform_driver_register(&usbtll_omap_driver);
+}
+
+/*
+ * init before usbhs core driver;
+ * The usbtll driver should be initialized before
+ * the usbhs core driver probe function is called.
+ */
+fs_initcall(omap_usbtll_drvinit);
+
+static void __exit omap_usbtll_drvexit(void)
+{
+       platform_driver_unregister(&usbtll_omap_driver);
+}
+module_exit(omap_usbtll_drvexit);