Re: [PATCH 3/3] usb: chipidea: imx: implement workaround for ERR051725

["Peter Chen (CIX)" <peter.chen@kernel.org>]

On 25-06-14 20:56:45, Xu Yang wrote:
> ERR051725:
> USB: With the USB controller configured as device mode, Clearing the RS
> bit of USBCMD register fails to cause USB device to be detached
> 
> Description
> 1. USB controller working as high speed device mode with USB gadget
>    function enabled
> 2. Cable plugged into USB host
> 3. Use case is software-controlled detach from USB device side
> 
> The expected result is device side terminations removed, increase in USB
> signal amplitude, USB host detect device is detached. But the issue is
> that the clear RS bit of USBCMD register cannot cause device detach event.
> 
> Workaround
> - Use the below steps to detach from the host:
>     write USBCMD.RS = 0b
>     write CTRL2[7:6] = 01b
>     write CTRL2[8] = 1b
> - As CTRL2[8] is set at detach case, so attach the steps should add clear
>   CTRL2[8]:
>     write USBCMD.RS = 1b
>     write CTRL2[8] = 0b
> 
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>

Acked-by: Peter Chen <peter.chen@kernel.org>

Peter
> ---
>  drivers/usb/chipidea/ci_hdrc_imx.c |  5 +++++
>  drivers/usb/chipidea/usbmisc_imx.c | 21 +++++++++++++++++++++
>  2 files changed, 26 insertions(+)
> 
> diff --git a/drivers/usb/chipidea/ci_hdrc_imx.c b/drivers/usb/chipidea/ci_hdrc_imx.c
> index 780f4d151345..79e466e17788 100644
> --- a/drivers/usb/chipidea/ci_hdrc_imx.c
> +++ b/drivers/usb/chipidea/ci_hdrc_imx.c
> @@ -331,6 +331,11 @@ static int ci_hdrc_imx_notify_event(struct ci_hdrc *ci, unsigned int event)
>  		if (ci->usb_phy)
>  			schedule_work(&ci->usb_phy->chg_work);
>  		break;
> +	case CI_HDRC_CONTROLLER_PULLUP_EVENT:
> +		if (ci->role == CI_ROLE_GADGET)
> +			imx_usbmisc_pullup(data->usbmisc_data,
> +					   ci->gadget.connected);
> +		break;
>  	default:
>  		break;
>  	}
> diff --git a/drivers/usb/chipidea/usbmisc_imx.c b/drivers/usb/chipidea/usbmisc_imx.c
> index 9db67d6d0ec4..415d3ba2e9ad 100644
> --- a/drivers/usb/chipidea/usbmisc_imx.c
> +++ b/drivers/usb/chipidea/usbmisc_imx.c
> @@ -998,6 +998,25 @@ static int usbmisc_imx7ulp_init(struct imx_usbmisc_data *data)
>  	return 0;
>  }
>  
> +static void usbmisc_imx7d_pullup(struct imx_usbmisc_data *data, bool on)
> +{
> +	struct imx_usbmisc *usbmisc = dev_get_drvdata(data->dev);
> +	unsigned long flags;
> +	u32 val;
> +
> +	spin_lock_irqsave(&usbmisc->lock, flags);
> +	val = readl(usbmisc->base + MX7D_USBNC_USB_CTRL2);
> +	if (!on) {
> +		val &= ~MX7D_USBNC_USB_CTRL2_OPMODE_OVERRIDE_MASK;
> +		val |= MX7D_USBNC_USB_CTRL2_OPMODE(1);
> +		val |= MX7D_USBNC_USB_CTRL2_OPMODE_OVERRIDE_EN;
> +	} else {
> +		val &= ~MX7D_USBNC_USB_CTRL2_OPMODE_OVERRIDE_EN;
> +	}
> +	writel(val, usbmisc->base + MX7D_USBNC_USB_CTRL2);
> +	spin_unlock_irqrestore(&usbmisc->lock, flags);
> +}
> +
>  static int usbmisc_imx7d_power_lost_check(struct imx_usbmisc_data *data)
>  {
>  	struct imx_usbmisc *usbmisc = dev_get_drvdata(data->dev);
> @@ -1115,6 +1134,7 @@ static const struct usbmisc_ops imx7d_usbmisc_ops = {
>  	.set_wakeup = usbmisc_imx7d_set_wakeup,
>  	.charger_detection = imx7d_charger_detection,
>  	.power_lost_check = usbmisc_imx7d_power_lost_check,
> +	.pullup = usbmisc_imx7d_pullup,
>  	.vbus_comparator_on = usbmisc_imx7d_vbus_comparator_on,
>  };
>  
> @@ -1131,6 +1151,7 @@ static const struct usbmisc_ops imx95_usbmisc_ops = {
>  	.set_wakeup = usbmisc_imx95_set_wakeup,
>  	.charger_detection = imx7d_charger_detection,
>  	.power_lost_check = usbmisc_imx7d_power_lost_check,
> +	.pullup = usbmisc_imx7d_pullup,
>  	.vbus_comparator_on = usbmisc_imx7d_vbus_comparator_on,
>  };
>  
> -- 
> 2.34.1
> 

-- 

Best regards,
Peter