USB: gadget: pxa2xx_udc supports inverted vbus

Some boards (like e.g. Tosa) invert the VBUS-detection signal:
it's low when a host is supplying VBUS, and high otherwise.
Allow specifying whether gpio_vbus value is inverted.

Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 9 insertions, 2 deletions

diff --git a/drivers/usb/gadget/pxa2xx_udc.c b/drivers/usb/gadget/pxa2xx_udc.c
index 4abf9d26d615..8bd9ce26bd95 100644
--- a/drivers/usb/gadget/pxa2xx_udc.c
+++ b/drivers/usb/gadget/pxa2xx_udc.c
@@ -127,8 +127,10 @@ static int is_vbus_present(void)
 {
         struct pxa2xx_udc_mach_info             *mach = the_controller->mach;
 
-        if (mach->gpio_vbus)
-                return gpio_get_value(mach->gpio_vbus);
+        if (mach->gpio_vbus) {
+                int value = gpio_get_value(mach->gpio_vbus);
+                return mach->gpio_vbus_inverted ? !value : value;
+        }
         if (mach->udc_is_connected)
                 return mach->udc_is_connected();
         return 1;
@@ -1398,6 +1400,9 @@ static irqreturn_t udc_vbus_irq(int irq, void *_dev)
         struct pxa2xx_udc       *dev = _dev;
         int                     vbus = gpio_get_value(dev->mach->gpio_vbus);
 
+        if (dev->mach->gpio_vbus_inverted)
+                vbus = !vbus;
+
         pxa2xx_udc_vbus_session(&dev->gadget, vbus);
         return IRQ_HANDLED;
 }
diff --git a/include/asm-arm/mach/udc_pxa2xx.h b/include/asm-arm/mach/udc_pxa2xx.h
index ff0a95715a07..f191e147ea90 100644
--- a/include/asm-arm/mach/udc_pxa2xx.h
+++ b/include/asm-arm/mach/udc_pxa2xx.h
@@ -19,7 +19,9 @@ struct pxa2xx_udc_mach_info {
          * with on-chip GPIOs not Lubbock's wierd hardware, can have a sane
          * VBUS IRQ and omit the methods above.  Store the GPIO number
          * here; for GPIO 0, also mask in one of the pxa_gpio_mode() bits.
+         * Note that sometimes the signals go through inverters...
          */
+        bool    gpio_vbus_inverted;
         u16     gpio_vbus;                      /* high == vbus present */
         u16     gpio_pullup;                    /* high == pullup activated */
 };