On Mon, Mar 13, 2023, Elson Roy Serrao wrote:
> An usb device can initate a remote wakeup and bring the link out of
> suspend as dictated by the DEVICE_REMOTE_WAKEUP feature selector.
> Add support to handle this packet and set the remote wakeup capability.
>
> Some hosts may take longer time to initiate the resume signaling after
> device triggers a remote wakeup. So add async support to the wakeup API
> by enabling link status change events.
>
> Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
> ---
> drivers/usb/dwc3/core.h | 2 ++
> drivers/usb/dwc3/ep0.c | 7 +++++
> drivers/usb/dwc3/gadget.c | 76 +++++++++++++++++++++++++++++++++++++++++++----
> 3 files changed, 79 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index b1bd631..416e0ef 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -1113,6 +1113,7 @@ struct dwc3_scratchpad_array {
> * 3 - Reserved
> * @dis_metastability_quirk: set to disable metastability quirk.
> * @dis_split_quirk: set to disable split boundary.
> + * @wakeup_configured: set if the device is configured for remote wakeup.
> * @imod_interval: set the interrupt moderation interval in 250ns
> * increments or 0 to disable.
> * @max_cfg_eps: current max number of IN eps used across all USB configs.
> @@ -1331,6 +1332,7 @@ struct dwc3 {
>
> unsigned dis_split_quirk:1;
> unsigned async_callbacks:1;
> + unsigned wakeup_configured:1;
>
> u16 imod_interval;
>
> diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
> index 61de693..8aa14a5 100644
> --- a/drivers/usb/dwc3/ep0.c
> +++ b/drivers/usb/dwc3/ep0.c
> @@ -356,6 +356,9 @@ static int dwc3_ep0_handle_status(struct dwc3 *dwc,
> usb_status |= 1 << USB_DEV_STAT_U1_ENABLED;
> if (reg & DWC3_DCTL_INITU2ENA)
> usb_status |= 1 << USB_DEV_STAT_U2_ENABLED;
> + } else {
> + usb_status |= dwc->gadget->wakeup_armed <<
> + USB_DEVICE_REMOTE_WAKEUP;
> }
>
> break;
> @@ -476,6 +479,10 @@ static int dwc3_ep0_handle_device(struct dwc3 *dwc,
>
> switch (wValue) {
> case USB_DEVICE_REMOTE_WAKEUP:
> + if (dwc->wakeup_configured)
> + dwc->gadget->wakeup_armed = set;
> + else
> + ret = -EINVAL;
> break;
> /*
> * 9.4.1 says only for SS, in AddressState only for
> diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
> index 07989c6..f37f949 100644
> --- a/drivers/usb/dwc3/gadget.c
> +++ b/drivers/usb/dwc3/gadget.c
> @@ -258,7 +258,7 @@ int dwc3_send_gadget_generic_command(struct dwc3 *dwc, unsigned int cmd,
> return ret;
> }
>
> -static int __dwc3_gadget_wakeup(struct dwc3 *dwc);
> +static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async);
>
> /**
> * dwc3_send_gadget_ep_cmd - issue an endpoint command
> @@ -325,7 +325,7 @@ int dwc3_send_gadget_ep_cmd(struct dwc3_ep *dep, unsigned int cmd,
>
> fallthrough;
> case DWC3_LINK_STATE_U3:
> - ret = __dwc3_gadget_wakeup(dwc);
> + ret = __dwc3_gadget_wakeup(dwc, false);
> dev_WARN_ONCE(dwc->dev, ret, "wakeup failed --> %d\n",
> ret);
> break;
> @@ -2269,6 +2269,22 @@ static const struct usb_ep_ops dwc3_gadget_ep_ops = {
>
> /* -------------------------------------------------------------------------- */
>
> +static void dwc3_gadget_enable_linksts_evts(struct dwc3 *dwc, bool set)
> +{
> + u32 reg;
> +
> + if (DWC3_VER_IS_PRIOR(DWC3, 250A))
> + return;
> +
> + reg = dwc3_readl(dwc->regs, DWC3_DEVTEN);
> + if (set)
> + reg |= DWC3_DEVTEN_ULSTCNGEN;
> + else
> + reg &= ~DWC3_DEVTEN_ULSTCNGEN;
> +
> + dwc3_writel(dwc->regs, DWC3_DEVTEN, reg);
> +}
> +
> static int dwc3_gadget_get_frame(struct usb_gadget *g)
> {
> struct dwc3 *dwc = gadget_to_dwc(g);
> @@ -2276,7 +2292,7 @@ static int dwc3_gadget_get_frame(struct usb_gadget *g)
> return __dwc3_gadget_get_frame(dwc);
> }
>
> -static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
> +static int __dwc3_gadget_wakeup(struct dwc3 *dwc, bool async)
> {
> int retries;
>
> @@ -2307,9 +2323,13 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
> return -EINVAL;
> }
>
> + if (async)
> + dwc3_gadget_enable_linksts_evts(dwc, true);
> +
> ret = dwc3_gadget_set_link_state(dwc, DWC3_LINK_STATE_RECOV);
> if (ret < 0) {
> dev_err(dwc->dev, "failed to put link in Recovery\n");
> + dwc3_gadget_enable_linksts_evts(dwc, false);
> return ret;
> }
>
> @@ -2321,6 +2341,13 @@ static int __dwc3_gadget_wakeup(struct dwc3 *dwc)
> dwc3_writel(dwc->regs, DWC3_DCTL, reg);
> }
>
> + /*
> + * Since link status change events are enabled we will receive
> + * an U0 event when wakeup is successful. So bail out.
> + */
> + if (async)
> + return 0;
> +
> /* poll until Link State changes to ON */
> retries = 20000;
>
> @@ -2346,13 +2373,36 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g)
> unsigned long flags;
> int ret;
>
> + if (!dwc->wakeup_configured) {
> + dev_err(dwc->dev, "remote wakeup not configured\n");
> + return -EINVAL;
> + }
> +
> spin_lock_irqsave(&dwc->lock, flags);
> - ret = __dwc3_gadget_wakeup(dwc);
> + if (!dwc->gadget->wakeup_armed) {
> + dev_err(dwc->dev, "not armed for remote wakeup\n");
> + spin_unlock_irqrestore(&dwc->lock, flags);
> + return -EINVAL;
> + }
> + ret = __dwc3_gadget_wakeup(dwc, true);
> +
> spin_unlock_irqrestore(&dwc->lock, flags);
>
> return ret;
> }
>
> +static int dwc3_gadget_set_remote_wakeup(struct usb_gadget *g, int set)
> +{
> + struct dwc3 *dwc = gadget_to_dwc(g);
> + unsigned long flags;
> +
> + spin_lock_irqsave(&dwc->lock, flags);
> + dwc->wakeup_configured = !!set;
> + spin_unlock_irqrestore(&dwc->lock, flags);
> +
> + return 0;
> +}
> +
> static int dwc3_gadget_set_selfpowered(struct usb_gadget *g,
> int is_selfpowered)
> {
> @@ -2978,6 +3028,7 @@ static void dwc3_gadget_async_callbacks(struct usb_gadget *g, bool enable)
> static const struct usb_gadget_ops dwc3_gadget_ops = {
> .get_frame = dwc3_gadget_get_frame,
> .wakeup = dwc3_gadget_wakeup,
> + .set_remote_wakeup = dwc3_gadget_set_remote_wakeup,
> .set_selfpowered = dwc3_gadget_set_selfpowered,
> .pullup = dwc3_gadget_pullup,
> .udc_start = dwc3_gadget_start,
> @@ -3819,6 +3870,8 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
>
> dwc->gadget->speed = USB_SPEED_UNKNOWN;
> dwc->setup_packet_pending = false;
> + dwc->gadget->wakeup_armed = false;
> + dwc3_gadget_enable_linksts_evts(dwc, false);
> usb_gadget_set_state(dwc->gadget, USB_STATE_NOTATTACHED);
>
> if (dwc->ep0state != EP0_SETUP_PHASE) {
> @@ -3912,6 +3965,8 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
> reg &= ~DWC3_DCTL_TSTCTRL_MASK;
> dwc3_gadget_dctl_write_safe(dwc, reg);
> dwc->test_mode = false;
> + dwc->gadget->wakeup_armed = false;
> + dwc3_gadget_enable_linksts_evts(dwc, false);
> dwc3_clear_stall_all_ep(dwc);
>
> /* Reset device address to zero */
> @@ -4064,7 +4119,7 @@ static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
> */
> }
>
> -static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
> +static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc, unsigned int evtinfo)
> {
> /*
> * TODO take core out of low power mode when that's
> @@ -4076,6 +4131,8 @@ static void dwc3_gadget_wakeup_interrupt(struct dwc3 *dwc)
> dwc->gadget_driver->resume(dwc->gadget);
> spin_lock(&dwc->lock);
> }
> +
> + dwc->link_state = evtinfo & DWC3_LINK_STATE_MASK;
> }
>
> static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
> @@ -4157,6 +4214,12 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
> }
>
> switch (next) {
> + case DWC3_LINK_STATE_U0:
> + if (dwc->gadget->wakeup_armed) {
> + dwc3_gadget_enable_linksts_evts(dwc, false);
> + dwc3_resume_gadget(dwc);
> + }
> + break;
> case DWC3_LINK_STATE_U1:
> if (dwc->speed == USB_SPEED_SUPER)
> dwc3_suspend_gadget(dwc);
> @@ -4225,7 +4288,7 @@ static void dwc3_gadget_interrupt(struct dwc3 *dwc,
> dwc3_gadget_conndone_interrupt(dwc);
> break;
> case DWC3_DEVICE_EVENT_WAKEUP:
> - dwc3_gadget_wakeup_interrupt(dwc);
> + dwc3_gadget_wakeup_interrupt(dwc, event->event_info);
> break;
> case DWC3_DEVICE_EVENT_HIBER_REQ:
> if (dev_WARN_ONCE(dwc->dev, !dwc->has_hibernation,
> @@ -4478,6 +4541,7 @@ int dwc3_gadget_init(struct dwc3 *dwc)
> dwc->gadget->sg_supported = true;
> dwc->gadget->name = "dwc3-gadget";
> dwc->gadget->lpm_capable = !dwc->usb2_gadget_lpm_disable;
> + dwc->gadget->wakeup_capable = true;
>
> /*
> * FIXME We might be setting max_speed to <SUPER, however versions
> --
> 2.7.4
>
Acked-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Thanks,
Thinh
