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. Regards, Chanwoo Choi -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
