3 files changed, 57 insertions, 13 deletions

diff --git a/arch/arm/mach-at91/include/mach/board.h b/arch/arm/mach-at91/include/mach/board.h
index df2ed848c9f8..58528aa9c8a8 100644
--- a/arch/arm/mach-at91/include/mach/board.h
+++ b/arch/arm/mach-at91/include/mach/board.h
@@ -44,6 +44,8 @@
  /* USB Device */
 struct at91_udc_data {
         u8      vbus_pin;               /* high == host powering us */
+        u8      vbus_active_low;        /* vbus polarity */
+        u8      vbus_polled;            /* Use polling, not interrupt */
         u8      pullup_pin;             /* active == D+ pulled up */
         u8      pullup_active_low;      /* true == pullup_pin is active low */
 };
diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index fd6a7577ad25..93ead19507b6 100644
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -76,6 +76,7 @@
 static const char driver_name [] = "at91_udc";
 static const char ep0name[] = "ep0";
 
+#define VBUS_POLL_TIMEOUT       msecs_to_jiffies(1000)
 
 #define at91_udp_read(udc, reg) \
         __raw_readl((udc)->udp_baseaddr + (reg))
@@ -1585,20 +1586,48 @@ static struct at91_udc controller = {
         /* ep6 and ep7 are also reserved (custom silicon might use them) */
 };
 
+static void at91_vbus_update(struct at91_udc *udc, unsigned value)
+{
+        value ^= udc->board.vbus_active_low;
+        if (value != udc->vbus)
+                at91_vbus_session(&udc->gadget, value);
+}
+
 static irqreturn_t at91_vbus_irq(int irq, void *_udc)
 {
         struct at91_udc *udc = _udc;
-        unsigned        value;
 
         /* vbus needs at least brief debouncing */
         udelay(10);
-        value = gpio_get_value(udc->board.vbus_pin);
-        if (value != udc->vbus)
-                at91_vbus_session(&udc->gadget, value);
+        at91_vbus_update(udc, gpio_get_value(udc->board.vbus_pin));
 
         return IRQ_HANDLED;
 }
 
+static void at91_vbus_timer_work(struct work_struct *work)
+{
+        struct at91_udc *udc = container_of(work, struct at91_udc,
+                                            vbus_timer_work);
+
+        at91_vbus_update(udc, gpio_get_value_cansleep(udc->board.vbus_pin));
+
+        if (!timer_pending(&udc->vbus_timer))
+                mod_timer(&udc->vbus_timer, jiffies + VBUS_POLL_TIMEOUT);
+}
+
+static void at91_vbus_timer(unsigned long data)
+{
+        struct at91_udc *udc = (struct at91_udc *)data;
+
+        /*
+         * If we are polling vbus it is likely that the gpio is on an
+         * bus such as i2c or spi which may sleep, so schedule some work
+         * to read the vbus gpio
+         */
+        if (!work_pending(&udc->vbus_timer_work))
+                schedule_work(&udc->vbus_timer_work);
+}
+
 int usb_gadget_register_driver (struct usb_gadget_driver *driver)
 {
         struct at91_udc *udc = &controller;
@@ -1800,13 +1829,23 @@ static int __init at91udc_probe(struct platform_device *pdev)
                  * Get the initial state of VBUS - we cannot expect
                  * a pending interrupt.
                  */
-                udc->vbus = gpio_get_value(udc->board.vbus_pin);
-                if (request_irq(udc->board.vbus_pin, at91_vbus_irq,
-                                IRQF_DISABLED, driver_name, udc)) {
-                        DBG("request vbus irq %d failed\n",
-                                        udc->board.vbus_pin);
-                        retval = -EBUSY;
-                        goto fail3;
+                udc->vbus = gpio_get_value_cansleep(udc->board.vbus_pin) ^
+                        udc->board.vbus_active_low;
+
+                if (udc->board.vbus_polled) {
+                        INIT_WORK(&udc->vbus_timer_work, at91_vbus_timer_work);
+                        setup_timer(&udc->vbus_timer, at91_vbus_timer,
+                                    (unsigned long)udc);
+                        mod_timer(&udc->vbus_timer,
+                                  jiffies + VBUS_POLL_TIMEOUT);
+                } else {
+                        if (request_irq(udc->board.vbus_pin, at91_vbus_irq,
+                                        IRQF_DISABLED, driver_name, udc)) {
+                                DBG("request vbus irq %d failed\n",
+                                    udc->board.vbus_pin);
+                                retval = -EBUSY;
+                                goto fail3;
+                        }
                 }
         } else {
                 DBG("no VBUS detection, assuming always-on\n");
@@ -1898,7 +1937,7 @@ static int at91udc_suspend(struct platform_device *pdev, pm_message_t mesg)
                 enable_irq_wake(udc->udp_irq);
 
         udc->active_suspend = wake;
-        if (udc->board.vbus_pin > 0 && wake)
+        if (udc->board.vbus_pin > 0 && !udc->board.vbus_polled && wake)
                 enable_irq_wake(udc->board.vbus_pin);
         return 0;
 }
@@ -1908,7 +1947,8 @@ static int at91udc_resume(struct platform_device *pdev)
         struct at91_udc *udc = platform_get_drvdata(pdev);
         unsigned long   flags;
 
-        if (udc->board.vbus_pin > 0 && udc->active_suspend)
+        if (udc->board.vbus_pin > 0 && !udc->board.vbus_polled &&
+            udc->active_suspend)
                 disable_irq_wake(udc->board.vbus_pin);
 
         /* maybe reconnect to host; if so, clocks on */
diff --git a/drivers/usb/gadget/at91_udc.h b/drivers/usb/gadget/at91_udc.h
index bc76a39c2bb1..108ca54f9092 100644
--- a/drivers/usb/gadget/at91_udc.h
+++ b/drivers/usb/gadget/at91_udc.h
@@ -145,6 +145,8 @@ struct at91_udc {
         void __iomem                    *udp_baseaddr;
         int                             udp_irq;
         spinlock_t                      lock;
+        struct timer_list               vbus_timer;
+        struct work_struct              vbus_timer_work;
 };
 
 static inline struct at91_udc *to_udc(struct usb_gadget *g)