Re: [v21 4/5] usb: dwc3: qcom: Configure wakeup interrupts during suspend

[Matthias Kaehlcke <mka@chromium.org>]

On Mon, Jun 13, 2022 at 10:00:53AM +0530, Krishna Kurapati wrote:
> From: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> 
> Configure DP/DM line interrupts based on the USB2 device attached to
> the root hub port. When HS/FS device is connected, configure the DP line
> as falling edge to detect both disconnect and remote wakeup scenarios. When
> LS device is connected, configure DM line as falling edge to detect both
> disconnect and remote wakeup. When no device is connected, configure both
> DP and DM lines as rising edge to detect HS/HS/LS device connect scenario.
> 
> Signed-off-by: Sandeep Maheswaram <quic_c_sanm@quicinc.com>
> Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
> Reviewed-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 72 ++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 62 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index 7352124..1046ea8 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -20,7 +20,8 @@
>  #include <linux/usb/of.h>
>  #include <linux/reset.h>
>  #include <linux/iopoll.h>
> -
> +#include <linux/usb/hcd.h>
> +#include <linux/usb.h>
>  #include "core.h"
>  
>  /* USB QSCRATCH Hardware registers */
> @@ -76,6 +77,7 @@ struct dwc3_qcom {
>  	int			dp_hs_phy_irq;
>  	int			dm_hs_phy_irq;
>  	int			ss_phy_irq;
> +	enum usb_device_speed	usb2_speed;
>  
>  	struct extcon_dev	*edev;
>  	struct extcon_dev	*host_edev;
> @@ -296,11 +298,34 @@ static void dwc3_qcom_interconnect_exit(struct dwc3_qcom *qcom)
>  	icc_put(qcom->icc_path_apps);
>  }
>  
> -static void dwc3_qcom_enable_wakeup_irq(int irq)
> +static enum usb_device_speed dwc3_qcom_read_usb2_speed(struct dwc3_qcom *qcom)
> +{
> +	struct dwc3 *dwc = platform_get_drvdata(qcom->dwc3);
> +	struct usb_hcd *hcd = platform_get_drvdata(dwc->xhci);
> +	struct usb_device *udev;
> +
> +	/*
> +	 * It is possible to query the speed of all children of
> +	 * USB2.0 root hub via usb_hub_for_each_child(). DWC3 code
> +	 * currently supports only 1 port per controller. So
> +	 * this is sufficient.
> +	 */

nit: not sure it's really valuable to mention what could be done
theoretically. Saying that the dwc3 driver currently only
supports one port per controller should be enough.

No need to respin for this,

> +	udev = usb_hub_find_child(hcd->self.root_hub, 1);
> +
> +	if (!udev)
> +		return USB_SPEED_UNKNOWN;
> +
> +	return udev->speed;
> +}
> +
> +static void dwc3_qcom_enable_wakeup_irq(int irq, unsigned int polarity)

'polarity' isn't really accurate, the parameter also encodes whether the IRQ
is edge or level triggered. 'irq_type' would be clearer.

Also no need to respin just for this.

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>