usb: musb: wake the device before ulpi transfers

musb can be suspended at the time some other driver wants to do ulpi
transfers using usb_phy_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 usb_phy so that pm_runtime_* functions can be used.

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

2 files changed, 26 insertions, 6 deletions

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 239214626ec5..66aaccf04490 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -137,6 +137,9 @@ static int musb_ulpi_read(struct usb_phy *phy, u32 offset)
         int     i = 0;
         u8      r;
         u8      power;
+        int     ret;
+
+        pm_runtime_get_sync(phy->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 usb_phy *phy, 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(phy->io_dev);
+
+        return ret;
 }
 
 static int musb_ulpi_write(struct usb_phy *phy, u32 offset, u32 data)
@@ -171,6 +181,9 @@ static int musb_ulpi_write(struct usb_phy *phy, u32 offset, u32 data)
         int     i = 0;
         u8      r = 0;
         u8      power;
+        int     ret = 0;
+
+        pm_runtime_get_sync(phy->io_dev);
 
         /* Make sure the transceiver is not in low power mode */
         power = musb_readb(addr, MUSB_POWER);
@@ -184,15 +197,20 @@ static int musb_ulpi_write(struct usb_phy *phy, u32 offset, u32 data)
         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(phy->io_dev);
+
+        return ret;
 }
 #else
 #define musb_ulpi_read          NULL
@@ -1908,6 +1926,7 @@ 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 f67810f8f21b..38ab3f46346f 100644
--- a/include/linux/usb/otg.h
+++ b/include/linux/usb/otg.h
@@ -94,6 +94,7 @@ struct usb_phy {
 
         struct usb_otg          *otg;
 
+        struct device           *io_dev;
         struct usb_phy_io_ops   *io_ops;
         void __iomem            *io_priv;