One bug fix for USB charger detection at imx7d and imx8m series SoCs
usb: chipidea: imx: Fix Battery Charger 1.2 CDP detection

i.MX8MM cannot detect certain CDP USB HUBs. usbmisc_imx.c driver is not
following CDP timing requirements defined by USB BC 1.2 specification
and section 3.2.4 Detection Timing CDP.

During Primary Detection the i.MX device should turn on VDP_SRC and
IDM_SINK for a minimum of 40ms (TVDPSRC_ON). After a time of TVDPSRC_ON,
the i.MX is allowed to check the status of the D- line. Current
implementation is waiting between 1ms and 2ms, and certain BC 1.2
complaint USB HUBs cannot be detected. Increase delay to 40ms allowing
enough time for primary detection.

During secondary detection the i.MX is required to disable VDP_SRC and
IDM_SNK, and enable VDM_SRC and IDP_SINK for at least 40ms (TVDMSRC_ON).

Current implementation is not disabling VDP_SRC and IDM_SNK, introduce
disable sequence in imx7d_charger_secondary_detection() function.

VDM_SRC and IDP_SINK should be enabled for at least 40ms (TVDMSRC_ON).
Increase delay allowing enough time for detection.

Cc: <>
Fixes: 746f316b753a ("usb: chipidea: introduce imx7d USB charger detection")
Signed-off-by: Breno Lima <>
Signed-off-by: Jun Li <>
Signed-off-by: Peter Chen <>
1 file changed