usb: musb: wake the device before ulpi transfers

musb can be suspended at the time some other driver wants to do ulpi
transfers using otg_io_* functions, and that can cause data abort,
as it happened with isp1704_charger:
http://article.gmane.org/gmane.linux.kernel/1226122

Add pm_runtime to ulpi functions to rectify this. This also adds io_dev
to otg_transceiver so that pm_runtime can be used.

Cc: Felipe Contreras <felipe.contreras@gmail.com>
Signed-off-by: Grazvydas Ignotas <notasas@gmail.com>

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 191c9ca..98c37d8 100644 (file)
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -137,6 +137,9 @@ static int musb_ulpi_read(struct otg_transceiver *otg, u32 offset)
        int     i = 0;
        u8      r;
        u8      power;
+       int     ret;
+
+       pm_runtime_get_sync(otg->io_dev);
 
        /* Make sure the transceiver is not in low power mode */
        power = musb_readb(addr, MUSB_POWER);
@@ -154,15 +157,22 @@ static int musb_ulpi_read(struct otg_transceiver *otg, u32 offset)
        while (!(musb_readb(addr, MUSB_ULPI_REG_CONTROL)
                                & MUSB_ULPI_REG_CMPLT)) {
                i++;
-               if (i == 10000)
-                       return -ETIMEDOUT;
+               if (i == 10000) {
+                       ret = -ETIMEDOUT;
+                       goto out;
+               }
 
        }
        r = musb_readb(addr, MUSB_ULPI_REG_CONTROL);
        r &= ~MUSB_ULPI_REG_CMPLT;
        musb_writeb(addr, MUSB_ULPI_REG_CONTROL, r);
 
-       return musb_readb(addr, MUSB_ULPI_REG_DATA);
+       ret = musb_readb(addr, MUSB_ULPI_REG_DATA);
+
+out:
+       pm_runtime_put(otg->io_dev);
+
+       return ret;
 }
 
 static int musb_ulpi_write(struct otg_transceiver *otg,
@@ -172,6 +182,9 @@ static int musb_ulpi_write(struct otg_transceiver *otg,
        int     i = 0;
        u8      r = 0;
        u8      power;
+       int     ret = 0;
+
+       pm_runtime_get_sync(otg->io_dev);
 
        /* Make sure the transceiver is not in low power mode */
        power = musb_readb(addr, MUSB_POWER);
@@ -185,15 +198,20 @@ static int musb_ulpi_write(struct otg_transceiver *otg,
        while (!(musb_readb(addr, MUSB_ULPI_REG_CONTROL)
                                & MUSB_ULPI_REG_CMPLT)) {
                i++;
-               if (i == 10000)
-                       return -ETIMEDOUT;
+               if (i == 10000) {
+                       ret = -ETIMEDOUT;
+                       goto out;
+               }
        }
 
        r = musb_readb(addr, MUSB_ULPI_REG_CONTROL);
        r &= ~MUSB_ULPI_REG_CMPLT;
        musb_writeb(addr, MUSB_ULPI_REG_CONTROL, r);
 
-       return 0;
+out:
+       pm_runtime_put(otg->io_dev);
+
+       return ret;
 }
 #else
 #define musb_ulpi_read         NULL
@@ -1955,6 +1973,7 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
        }
 
        if (!musb->xceiv->io_ops) {
+               musb->xceiv->io_dev = musb->controller;
                musb->xceiv->io_priv = musb->mregs;
                musb->xceiv->io_ops = &musb_ulpi_access;
        }

diff --git a/include/linux/usb/otg.h b/include/linux/usb/otg.h
index d87f44f..308b699 100644 (file)
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -71,6 +71,7 @@ struct otg_transceiver {
        struct usb_bus          *host;
        struct usb_gadget       *gadget;
 
+       struct device                   *io_dev;
        struct otg_io_access_ops        *io_ops;
        void __iomem                    *io_priv;