@@ -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;
+ /*
+ * 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:
- /*
- * Once we have IIO support for the GPADC we should read
- * the USBID GPADC channel here and determine ACA role
- * based on that.
- */
return INTEL_USB_ID_FLOAT;
}
}
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. Signed-off-by: Hans de Goede <hdegoede@redhat.com> --- drivers/extcon/extcon-intel-cht-wc.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)