Commit 21356ac1 authored by Hans de Goede's avatar Hans de Goede Committed by Sebastian Reichel
Browse files

extcon: intel-cht-wc: Report RID_A for ACA adapters 



Make cht_wc_extcon_get_id() report RID_A for ACA adapters, instead of
reporting ID_FLOAT.

According to the spec. we should read the USB-ID pin ADC value
to determine the resistance of the used pull-down resister and
then return RID_A / RID_B / RID_C based on this. But all "Accessory
Charger Adapter"s (ACAs) which users can actually buy always use
a combination of a charging port with one or more USB-A ports, so
they should always use a resistor indicating RID_A. But the spec
is hard to read / badly-worded so some of them actually indicate
they are a RID_B ACA even though they clearly are a RID_A ACA.

To workaround this simply always return INTEL_USB_RID_A, which
matches all the ACAs which users can actually buy.

Acked-by: default avatarChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Signed-off-by: default avatarSebastian Reichel <sebastian.reichel@collabora.com>
parent 66e31186

drivers/extcon/extcon-intel-cht-wc.c

+13 −5
Original line number Diff line number Diff line
@@ -121,13 +121,21 @@ static int cht_wc_extcon_get_id(struct cht_wc_extcon_data *ext, int pwrsrc_sts) 
		return INTEL_USB_ID_GND;

	case CHT_WC_PWRSRC_RID_FLOAT:

		return INTEL_USB_ID_FLOAT;

	case CHT_WC_PWRSRC_RID_ACA:

	default:

	/*

		 * Once we have IIO support for the GPADC we should read

		 * the USBID GPADC channel here and determine ACA role

		 * based on that.

	 * According to the spec. we should read the USB-ID pin ADC value here

	 * to determine the resistance of the used pull-down resister and then

	 * return RID_A / RID_B / RID_C based on this. But all "Accessory

	 * Charger Adapter"s (ACAs) which users can actually buy always use

	 * a combination of a charging port with one or more USB-A ports, so

	 * they should always use a resistor indicating RID_A. But the spec

	 * is hard to read / badly-worded so some of them actually indicate

	 * they are a RID_B ACA evnen though they clearly are a RID_A ACA.

	 * To workaround this simply always return INTEL_USB_RID_A, which

	 * matches all the ACAs which users can actually buy.

	 */

	case CHT_WC_PWRSRC_RID_ACA:

		return INTEL_USB_RID_A;

	default:

		return INTEL_USB_ID_FLOAT;

	}

}