[PATCH 4.9 19/31] usb: musb: Disable pullup at init

[Greg Kroah-Hartman]

From: Paul Cercueil <paul@xxxxxxxxxxxxxxx>

commit 96a0c12843109e5c4d5eb1e09d915fdd0ce31d25 upstream.

The pullup may be already enabled before the driver is initialized. This
happens for instance on JZ4740.

It has to be disabled at init time, as we cannot guarantee that a gadget
driver will be bound to the UDC.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
Suggested-by: Bin Liu <b-liu@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Link: https://lore.kernel.org/r/20200107152625.857-3-b-liu@xxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/usb/musb/musb_core.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2317,6 +2317,9 @@ musb_init_controller(struct device *dev,
 	musb_platform_disable(musb);
 	musb_generic_disable(musb);
 
+	/* MUSB_POWER_SOFTCONN might be already set, JZ4740 does this. */
+	musb_writeb(musb->mregs, MUSB_POWER, 0);
+
 	/* Init IRQ workqueue before request_irq */
 	INIT_DELAYED_WORK(&musb->irq_work, musb_irq_work);
 	INIT_DELAYED_WORK(&musb->deassert_reset_work, musb_deassert_reset);