usb: dwc3-msm: Add support for LPM on cable disconnect
Add runtime power management support in the driver which allows
putting the hardware in low power state, turning off LDOs
and releasing wakelock.
This LPM (aka low power state) support is currently added as part
of USB disconnect and wall-charger connect. LPM support would
later be extended to USB bus suspend as well. Also, support for PHY
retention mode and VDD minimization would be added later.
This commit also adds debugfs nodes that can used to simulate
cable connect and disconnects as A or B device. Following are
the nodes:
-->msm_dwc3/id : Boolean value
-->msm_dwc3/bsv : Boolean value
-->msm_dwc3/connect : can be set to enable/disable
User should first update id/bsv values before enabling 'connect'.
dwc3-msm device is parent of dwc3-core and its runtime PM is managed
by dwc3_otg driver which is responsible for the state transitions
based on notifications from DWC3 h/w or ext_xceiver (using PMIC) for
cable connect and disconnect. This change also allows dwc3 gadget and
host to acquire PM count for the case when dwc3-otg is not present -
e.g. host and device only configurations.
Change-Id: Idd9a59c1ffd46bd98228c9fd4441f668b763534d
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>
diff --git a/drivers/usb/dwc3/dwc3_otg.c b/drivers/usb/dwc3/dwc3_otg.c
index 23b582d..4a37f03 100644
--- a/drivers/usb/dwc3/dwc3_otg.c
+++ b/drivers/usb/dwc3/dwc3_otg.c
@@ -271,6 +271,61 @@
return 0;
}
+/**
+ * dwc3_ext_event_notify - callback to handle events from external transceiver
+ * @otg: Pointer to the otg transceiver structure
+ * @event: Event reported by transceiver
+ *
+ * Returns 0 on success
+ */
+static void dwc3_ext_event_notify(struct usb_otg *otg,
+ enum dwc3_ext_events event)
+{
+ struct dwc3_otg *dotg = container_of(otg, struct dwc3_otg, otg);
+ struct dwc3_ext_xceiv *ext_xceiv = dotg->ext_xceiv;
+ struct usb_phy *phy = dotg->otg.phy;
+
+ if (event == DWC3_EVENT_PHY_RESUME) {
+ if (!pm_runtime_status_suspended(phy->dev)) {
+ dev_warn(phy->dev, "PHY_RESUME event out of LPM!!!!\n");
+ } else {
+ dev_dbg(phy->dev, "ext PHY_RESUME event received\n");
+ /* ext_xceiver would have taken h/w out of LPM by now */
+ pm_runtime_get(phy->dev);
+ }
+ }
+
+ if (ext_xceiv->id == DWC3_ID_FLOAT)
+ set_bit(ID, &dotg->inputs);
+ else
+ clear_bit(ID, &dotg->inputs);
+
+ if (ext_xceiv->bsv)
+ set_bit(B_SESS_VLD, &dotg->inputs);
+ else
+ clear_bit(B_SESS_VLD, &dotg->inputs);
+
+ schedule_work(&dotg->sm_work);
+}
+
+/**
+ * dwc3_set_ext_xceiv - bind/unbind external transceiver driver
+ * @otg: Pointer to the otg transceiver structure
+ * @ext_xceiv: Pointer to the external transceiver struccture
+ *
+ * Returns 0 on success
+ */
+int dwc3_set_ext_xceiv(struct usb_otg *otg, struct dwc3_ext_xceiv *ext_xceiv)
+{
+ struct dwc3_otg *dotg = container_of(otg, struct dwc3_otg, otg);
+
+ dotg->ext_xceiv = ext_xceiv;
+ if (ext_xceiv)
+ ext_xceiv->notify_ext_events = dwc3_ext_event_notify;
+
+ return 0;
+}
+
/* IRQs which OTG driver is interested in handling */
#define DWC3_OEVT_MASK (DWC3_OEVTEN_OTGCONIDSTSCHNGEVNT | \
DWC3_OEVTEN_OTGBDEVVBUSCHNGEVNT)
@@ -284,10 +339,21 @@
static irqreturn_t dwc3_otg_interrupt(int irq, void *_dotg)
{
struct dwc3_otg *dotg = (struct dwc3_otg *)_dotg;
+ struct usb_phy *phy = dotg->otg.phy;
u32 osts, oevt_reg;
int ret = IRQ_NONE;
int handled_irqs = 0;
+ /*
+ * If PHY is in retention mode then this interrupt would not be fired.
+ * ext_xcvr (parent) is responsible for bringing h/w out of LPM.
+ * OTG driver just need to increment power count and can safely
+ * assume that h/w is out of low power state now.
+ * TODO: explicitly disable OEVTEN interrupts if ext_xceiv is present
+ */
+ if (pm_runtime_status_suspended(phy->dev))
+ pm_runtime_get(phy->dev);
+
oevt_reg = dwc3_readl(dotg->regs, DWC3_OEVT);
if (!(oevt_reg & DWC3_OEVT_MASK))
@@ -371,6 +437,7 @@
struct dwc3_charger *charger = dotg->charger;
bool work = 0;
+ pm_runtime_resume(phy->dev);
dev_dbg(phy->dev, "%s state\n", otg_state_string(phy->state));
/* Check OTG state */
@@ -388,7 +455,8 @@
work = 1;
} else {
phy->state = OTG_STATE_B_IDLE;
- /* TODO: Enter low power state */
+ dev_dbg(phy->dev, "No device, trying to suspend\n");
+ pm_runtime_put_sync(phy->dev);
}
break;
@@ -411,7 +479,8 @@
/* Has charger been detected? If no detect it */
switch (charger->chg_type) {
case DWC3_DCP_CHARGER:
- /* TODO: initiate LPM */
+ dev_dbg(phy->dev, "lpm, DCP charger\n");
+ pm_runtime_put_sync(phy->dev);
break;
case DWC3_CDP_CHARGER:
dwc3_otg_start_peripheral(&dotg->otg,
@@ -438,9 +507,10 @@
* yet. We will re-try as soon as it
* will be called
*/
- dev_err(phy->dev,
+ dev_err(phy->dev, "enter lpm as\n"
"unable to start B-device\n");
phy->state = OTG_STATE_UNDEFINED;
+ pm_runtime_put_sync(phy->dev);
return;
}
}
@@ -453,7 +523,8 @@
charger->chg_type =
DWC3_INVALID_CHARGER;
}
- /* TODO: Enter low power state */
+ dev_dbg(phy->dev, "No device, trying to suspend\n");
+ pm_runtime_put_sync(phy->dev);
}
break;
@@ -481,9 +552,10 @@
* Probably set_host was not called yet.
* We will re-try as soon as it will be called
*/
- dev_dbg(phy->dev,
+ dev_dbg(phy->dev, "enter lpm as\n"
"unable to start A-device\n");
phy->state = OTG_STATE_UNDEFINED;
+ pm_runtime_put_sync(phy->dev);
return;
}
phy->state = OTG_STATE_A_HOST;
@@ -628,6 +700,8 @@
goto err3;
}
+ pm_runtime_get(dwc->dev);
+
return 0;
err3:
@@ -658,6 +732,7 @@
dotg->charger->start_detection(dotg->charger, false);
cancel_work_sync(&dotg->sm_work);
usb_set_transceiver(NULL);
+ pm_runtime_put(dwc->dev);
free_irq(dotg->irq, dotg);
kfree(dotg->otg.phy);
kfree(dotg);