[PATCH v2 2/5] usb: dwc3: Add remote wakeup handling
From: Elson Roy Serrao
Date: Tue Jan 17 2023 - 17:01:19 EST
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 | 3 +++
drivers/usb/dwc3/ep0.c | 4 ++++
drivers/usb/dwc3/gadget.c | 57 ++++++++++++++++++++++++++++++++++++++++++-----
3 files changed, 58 insertions(+), 6 deletions(-)
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index 8f9959b..53ded08 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -1117,6 +1117,8 @@ struct dwc3_scratchpad_array {
* address.
* @num_ep_resized: carries the current number endpoints which have had its tx
* fifo resized.
+ * @rw_armed: Indicates whether the host has armed the device for remote
+ * wakeup.
*/
struct dwc3 {
struct work_struct drd_work;
@@ -1332,6 +1334,7 @@ struct dwc3 {
int max_cfg_eps;
int last_fifo_depth;
int num_ep_resized;
+ bool rw_armed;
};
#define INCRX_BURST_MODE 0
diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c
index 61de693..0c1203d 100644
--- a/drivers/usb/dwc3/ep0.c
+++ b/drivers/usb/dwc3/ep0.c
@@ -356,6 +356,8 @@ 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->rw_armed << USB_DEVICE_REMOTE_WAKEUP;
}
break;
@@ -476,6 +478,8 @@ static int dwc3_ep0_handle_device(struct dwc3 *dwc,
switch (wValue) {
case USB_DEVICE_REMOTE_WAKEUP:
+ if (dwc->gadget->rw_capable)
+ dwc->rw_armed = set;
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 89dcfac..db4b438 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 +2269,19 @@ static const struct usb_ep_ops dwc3_gadget_ep_ops = {
/* -------------------------------------------------------------------------- */
+static void dwc3_gadget_enable_linksts_evts(struct dwc3 *dwc, bool set)
+{
+ u32 reg;
+
+ 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 +2289,7 @@ 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 +2320,13 @@ 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 +2338,13 @@ 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;
@@ -2347,7 +2371,13 @@ static int dwc3_gadget_wakeup(struct usb_gadget *g)
int ret;
spin_lock_irqsave(&dwc->lock, flags);
- ret = __dwc3_gadget_wakeup(dwc);
+ if (!dwc->rw_armed) {
+ dev_err(dwc->dev, "%s:remote wakeup not enabled\n", __func__);
+ spin_unlock_irqrestore(&dwc->lock, flags);
+ return -EINVAL;
+ }
+ ret = __dwc3_gadget_wakeup(dwc, true);
+
spin_unlock_irqrestore(&dwc->lock, flags);
return ret;
@@ -2813,6 +2843,8 @@ static int dwc3_gadget_start(struct usb_gadget *g,
spin_lock_irqsave(&dwc->lock, flags);
dwc->gadget_driver = driver;
+ dwc3_gadget_enable_linksts_evts(dwc, false);
+ dwc->rw_armed = false;
spin_unlock_irqrestore(&dwc->lock, flags);
return 0;
@@ -2832,6 +2864,8 @@ static int dwc3_gadget_stop(struct usb_gadget *g)
spin_lock_irqsave(&dwc->lock, flags);
dwc->gadget_driver = NULL;
+ dwc3_gadget_enable_linksts_evts(dwc, false);
+ dwc->rw_armed = false;
dwc->max_cfg_eps = 0;
spin_unlock_irqrestore(&dwc->lock, flags);
@@ -3821,6 +3855,8 @@ static void dwc3_gadget_disconnect_interrupt(struct dwc3 *dwc)
dwc->gadget->speed = USB_SPEED_UNKNOWN;
dwc->setup_packet_pending = false;
+ dwc3_gadget_enable_linksts_evts(dwc, false);
+ dwc->rw_armed = false;
usb_gadget_set_state(dwc->gadget, USB_STATE_NOTATTACHED);
if (dwc->ep0state != EP0_SETUP_PHASE) {
@@ -3920,6 +3956,9 @@ static void dwc3_gadget_reset_interrupt(struct dwc3 *dwc)
reg = dwc3_readl(dwc->regs, DWC3_DCFG);
reg &= ~(DWC3_DCFG_DEVADDR_MASK);
dwc3_writel(dwc->regs, DWC3_DCFG, reg);
+
+ dwc3_gadget_enable_linksts_evts(dwc, false);
+ dwc->rw_armed = false;
}
static void dwc3_gadget_conndone_interrupt(struct dwc3 *dwc)
@@ -4066,7 +4105,7 @@ 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
@@ -4078,6 +4117,8 @@ 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,
@@ -4159,6 +4200,10 @@ static void dwc3_gadget_linksts_change_interrupt(struct dwc3 *dwc,
}
switch (next) {
+ case DWC3_LINK_STATE_U0:
+ 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);
@@ -4227,7 +4272,7 @@ 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,
--
2.7.4