Hi, On 09/06/16 12:32, Chanwoo Choi wrote: > Hi, > > On 2016년 06월 09일 17:39, Krzysztof Kozlowski wrote: >> >> Hi, >> >> >> On 06/09/2016 10:35 AM, Chanwoo Choi wrote: >>> Hi, >>> >>> It is good to support USB_ID and USB_VBUS by extcon. >>> >>> But, >>> there is some issue about adding the new cable type for >>> both EXTCON_USB_ID and EXTCON_USB_VBUS >>> >>> I think that the ID and VBUS state are not cable type >>> Instead, ID and VBUS state are the property of USB cable. >>> >>> So, I'd like to add the following function to support >>> the property of each cable as following: >>> The client driver can get the state of property by using >>> the extcon_get_cable_property_state(). >>> >>> - int extcon_get_cable_property_state(struct extcon_dev *edev, >>> unsigned int id, >>> enum extcon_property property); >>> - int extcon_set_cable_property_state(struct extcon_dev *edev, >>> unsigned int id, >>> enum extcon_property property, >>> unsigned int state); >>> >>> For example, >>> In extcon-usb-gpio.c, set state of property as follwoing: >>> extcon_set_cable_property_state(edev, EXTCON_USB, EXTCON_USB_PROP_ID, 1); >>> extcon_set_cable_property_state(edev, EXTCON_USB, EXTCON_USB_PROP_VBUS, 1); >>> >>> >>> In the extcon client driver, get state of property as following: >>> id_state = extcon_get_cable_property_state(edev, EXTCON_USB, EXTCON_USB_PROP_ID); >>> vbus_state = extcon_get_cable_property_state(edev, EXTCON_USB, EXTCON_USB_PROP_VUBS); >> >> How one can receive notifications with this API? > > I think that the extcon don't support the notification only for property. > When USB or USB_HOST cable state is changed, the client driver > call the extcon_get_cable_property_state() to read the state of property. > > Namely, the property depend on the specific external connector. > >> >> Last time you wrote, at the end of discussion: >> http://thread.gmane.org/gmane.linux.kernel/1923192/focus=1923193 >>> IMO, if some usb driver check both id and vbus pin at the same time, >>> the usb driver can know the both id and vbus pin state through only >> one notifier event. >>> >>> Also, >>> If some usb driver want to know the state of id pin except of vbus state, >>> when receiving following events, id pin is low. >>> #define EXTCON_USB_ID_L_VBUS_L0 >>> #define EXTCON_USB_ID_L_VBUS_H1 >>> when receiving following events, id pin is high. >>> #define EXTCON_USB_ID_H_VBUS_L2 >>> #define EXTCON_USB_ID_H_VBUS_H3 >>> Also, some usb driver would catch the vbus pin state with same method. >>> >>> But, it is just my opinion. We may use following notifier events for >> each pin. >>> We need to discuss it. >>> #define EXTCON_USB_ID_LOW >>> #define EXTCON_USB_ID_HIGH >>> #define EXTCON_USB_VBUS_LOW >>> #define EXTCON_USB_VBUS_HIGH >> >> ... all other participants agreed on that conclusion. So why change of >> view point now? > > Unitl now, the extcon framework only handle the state of external connector(cable). > - The state of external connector is either attached or detached. > > I think that ID and VBUS are not external connector(cable). > The ID and VBUS are more appropriate as property than new type of external connector. > Was there any conclusion on how we can support raw ID and VBUS events with extcon? cheers, -roger -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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