diff mbox series

[v3,7/7] usb: musb: jz4740: Disable pullup at init

Message ID 20191210171110.62141-7-paul@crapouillou.net (mailing list archive)
State New, archived
Headers show
Series [v3,1/7] usb: musb: dma: Correct parameter passed to IRQ handler | expand

Commit Message

Paul Cercueil Dec. 10, 2019, 5:11 p.m. UTC
The pullup may be already enabled before the driver is initialized.
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@crapouillou.net>
---

Notes:
    v3: New patch

 drivers/usb/musb/jz4740.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Bin Liu Dec. 10, 2019, 7:52 p.m. UTC | #1
Hi,

On Tue, Dec 10, 2019 at 06:11:10PM +0100, Paul Cercueil wrote:
> The pullup may be already enabled before the driver is initialized.
> 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@crapouillou.net>
> ---
> 
> Notes:
>     v3: New patch
> 
>  drivers/usb/musb/jz4740.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
> index f948eca654f3..1af9e4053312 100644
> --- a/drivers/usb/musb/jz4740.c
> +++ b/drivers/usb/musb/jz4740.c
> @@ -75,6 +75,7 @@ static const struct musb_hdrc_config jz4740_musb_config = {
>  static int jz4740_musb_init(struct musb *musb)
>  {
>  	struct device *dev = musb->controller->parent;
> +	u8 power;
>  	int err;
>  
>  	if (dev->of_node)
> @@ -97,6 +98,14 @@ static int jz4740_musb_init(struct musb *musb)
>  	musb->isr = jz4740_musb_interrupt;
>  	musb->dma_share_usb_irq = true;
>  
> +	/*
> +	 * If the SoC booted from USB the pullup might still be set.
> +	 * Disable it until a gadget is bound.
> +	 */
> +	power = musb_readb(musb->mregs, MUSB_POWER);
> +	power &= ~MUSB_POWER_SOFTCONN;
> +	musb_writeb(musb->mregs, MUSB_POWER, power);
> +
>  	return 0;
>  }

It is preferred the glue drivers don't touch the controller core
registers if possible. Please try the following patch instead.

-Bin.

------------- >8 ------------
t a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 683b719c5026..2f9105e8ea38 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -2317,6 +2317,9 @@ musb_init_controller(struct device *dev, int nIrq, void __iomem *ctrl)
        musb_disable_interrupts(musb);
        musb_writeb(musb->mregs, MUSB_DEVCTL, 0);

+       /* 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);
diff mbox series

Patch

diff --git a/drivers/usb/musb/jz4740.c b/drivers/usb/musb/jz4740.c
index f948eca654f3..1af9e4053312 100644
--- a/drivers/usb/musb/jz4740.c
+++ b/drivers/usb/musb/jz4740.c
@@ -75,6 +75,7 @@  static const struct musb_hdrc_config jz4740_musb_config = {
 static int jz4740_musb_init(struct musb *musb)
 {
 	struct device *dev = musb->controller->parent;
+	u8 power;
 	int err;
 
 	if (dev->of_node)
@@ -97,6 +98,14 @@  static int jz4740_musb_init(struct musb *musb)
 	musb->isr = jz4740_musb_interrupt;
 	musb->dma_share_usb_irq = true;
 
+	/*
+	 * If the SoC booted from USB the pullup might still be set.
+	 * Disable it until a gadget is bound.
+	 */
+	power = musb_readb(musb->mregs, MUSB_POWER);
+	power &= ~MUSB_POWER_SOFTCONN;
+	musb_writeb(musb->mregs, MUSB_POWER, power);
+
 	return 0;
 }