Skip to content

Commit

Permalink
usb:typec:tcpm:support double Rp to Vbus cable as sink
Browse files Browse the repository at this point in the history
The USB Type-C Cable and Connector Specification defines the wire
connections for the USB Type-C to USB 2.0 Standard-A cable assembly
(Release 2.2, Chapter 3.5.2).
The Notes says that Pin A5 (CC) of the USB Type-C plug shall be connected
to Vbus through a resister Rp.
However, there is a large amount of such double Rp connected to Vbus
non-standard cables which produced by UGREEN circulating on the market, and
it can affects the normal operations of the state machine easily,
especially to CC1 and CC2 be pulled up at the same time.
In fact, we can regard those cables as sink to avoid abnormal state.

Message as follow:
[   58.900212] VBUS on
[   59.265433] CC1: 0 -> 3, CC2: 0 -> 3 [state TOGGLING, polarity 0, connected]
[   62.623308] CC1: 3 -> 0, CC2: 3 -> 0 [state TOGGLING, polarity 0, disconnected]
[   62.625006] VBUS off
[   62.625012] VBUS VSAFE0V

Signed-off-by: Michael Wu <michael@allwinnertech.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20230920063030.66312-1-michael@allwinnertech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
Michael Wu authored and Greg Kroah-Hartman committed Oct 2, 2023
1 parent 5c954e0 commit dbc1def
Showing 1 changed file with 2 additions and 2 deletions.
4 changes: 2 additions & 2 deletions drivers/usb/typec/tcpm/tcpm.c
Original file line number Diff line number Diff line change
Expand Up @@ -517,9 +517,9 @@ static const char * const pd_rev[] = {
((cc) == TYPEC_CC_RP_DEF || (cc) == TYPEC_CC_RP_1_5 || \
(cc) == TYPEC_CC_RP_3_0)

/* As long as cc is pulled up, we can consider it as sink. */
#define tcpm_port_is_sink(port) \
((tcpm_cc_is_sink((port)->cc1) && !tcpm_cc_is_sink((port)->cc2)) || \
(tcpm_cc_is_sink((port)->cc2) && !tcpm_cc_is_sink((port)->cc1)))
(tcpm_cc_is_sink((port)->cc1) || tcpm_cc_is_sink((port)->cc2))

#define tcpm_cc_is_source(cc) ((cc) == TYPEC_CC_RD)
#define tcpm_cc_is_audio(cc) ((cc) == TYPEC_CC_RA)
Expand Down

0 comments on commit dbc1def

Please sign in to comment.