[v2,2/3] usb: musb: Add a quirk to preserve the session during suspend

Message ID 1481885176-16984-3-git-send-email-abailon@baylibre.com
State New
Headers show

Commit Message

Alexandre Bailon Dec. 16, 2016, 10:46 a.m.
On da8xx, VBUS is not maintained during suspend when musb is in host mode.
On resume, all the connected devices will be disconnected and then will
be enumerated again.
This happens because MUSB_DEVCTL is cleared during suspend.
Add a quirk to not clear MUSB_DEVCTL and then preserve the  session during
a suspend.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>

---
 drivers/usb/musb/musb_core.c | 3 ++-
 drivers/usb/musb/musb_core.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

-- 
2.7.3

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diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 56a4b97..c32024e 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2657,7 +2657,8 @@  static int musb_suspend(struct device *dev)
 
 	musb_platform_disable(musb);
 	musb_disable_interrupts(musb);
-	musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
+	if (!(musb->io.quirks & MUSB_PRESERVE_SESSION))
+		musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
 	WARN_ON(!list_empty(&musb->pending_list));
 
 	spin_lock_irqsave(&musb->lock, flags);
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index a611e2f..d9de3ca 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -172,6 +172,7 @@  struct musb_io;
  */
 struct musb_platform_ops {
 
+#define MUSB_PRESERVE_SESSION	BIT(7)
 #define MUSB_DMA_UX500		BIT(6)
 #define MUSB_DMA_CPPI41		BIT(5)
 #define MUSB_DMA_CPPI		BIT(4)