Support for SUSPEND and RESUME for USB chargers

Hi,

The charging should be prevented if the bus is suspended.

These notifications will come from the udc drivers. I'll create a separate patch set for those, as I guess the maintainers of the controller drivers need to approve those.

Heikki Krogerus (3):
usb: otg: add events for suspend/resume states
isp1704_charger: Handle suspended and resumed events
twl4030_charger: Handle suspended and resumed events

 drivers/power/isp1704_charger.c |   13 +++++++++++++
 drivers/power/twl4030_charger.c |    4 ++++
 include/linux/usb/otg.h         |    2 ++
 3 files changed, 19 insertions(+), 0 deletions(-)

1.7.4.1

Those will be used by the charger driver to cut current drawing when suspended and restart it when resumed.

---
 include/linux/usb/otg.h |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

index d87f44f..5f14caf 100644
@@ -41,6 +41,8 @@ enum usb_xceiv_events {
 	USB_EVENT_ID,           /* id was grounded */
 	USB_EVENT_CHARGER,      /* usb dedicated charger */
 	USB_EVENT_ENUMERATED,   /* gadget driver enumerated */
+	USB_EVENT_SUSPENDED,	/* gadget driver suspended */
+	USB_EVENT_RESUMED,	/* gadget driver resumed */
 };
 
 struct otg_transceiver;

1.7.4.1

To prevent charging when the bus is suspended, handling suspended and resumed events.

---
 drivers/power/isp1704_charger.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

index f6d72b4..c0d4e8b 100644
@@ -294,6 +294,19 @@ static void isp1704_charger_work(struct work_struct *data)
 		else
 			isp->current_max = power;
 		break;
+	case USB_EVENT_SUSPENDED:
+		/* Ignore SUSPEND with CDP */
+		if (isp->present)
+			goto out;
+		else
+			isp->current_max = 2;
+		break;
+	case USB_EVENT_RESUMED:
+		if (isp->present)
+			goto out;
+		else
+			isp->current_max = power;
+		break;
 	default:
 		goto out;
 	}

1.7.4.1

To prevent charging when the bus is suspended, handling suspended and resumed events.

---
 drivers/power/twl4030_charger.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)

index 92c16e1..461c389 100644
@@ -268,11 +268,15 @@ static void twl4030_bci_usb_work(struct work_struct *data)
 	switch (bci->event) {
 	case USB_EVENT_VBUS:
 	case USB_EVENT_CHARGER:
+	case USB_EVENT_RESUMED:
 		twl4030_charger_enable_usb(bci, true);
 		break;
 	case USB_EVENT_NONE:
+	case USB_EVENT_SUSPENDED:
 		twl4030_charger_enable_usb(bci, false);
 		break;
+	default:
+		break;
 	}
 }
 

1.7.4.1

Can you send them here as well? These patches never set this value, so I don't see why you did it this way, instead of just getting the "normal" suspend/resume callback and triggering off of that.

Still confused,

greg k-h

I'm not completely sure what you mean with "normal" suspend/resume callback? I want to get the information about the SUSPEND and RESUME bus states to the charger drivers and I don't want to tie them with any USB transceiver or controller driver. Wasn't this the reason for having the otg notifiers in the first place?

I'll spend a bit more time with these and resend when I have everything ready. Gražvydas noticed an issue with the isp1704_charger.c so that patch is broken in any case.

I did not think this through. Sorry about that. I should have send everything from the beginning and I should have been more clear what I'm after with these.

heikki