linux/drivers/usb/typec
Badhri Jagan Sridharan 23b5f73266 usb: typec: tcpm: Do not disconnect link for self powered devices
During HARD_RESET the data link is disconnected.
For self powered device, the spec is advising against doing that.

>From USB_PD_R3_0
7.1.5 Response to Hard Resets
Device operation during and after a Hard Reset is defined as follows:
Self-powered devices Should Not disconnect from USB during a Hard Reset
(see Section 9.1.2).
Bus powered devices will disconnect from USB during a Hard Reset due to the
loss of their power source.

Tackle this by letting TCPM know whether the device is self or bus powered.

This overcomes unnecessary port disconnections from hard reset.
Also, speeds up the enumeration time when connected to Type-A ports.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---------
Version history:
V3:
Rebase on top of usb-next

V2:
Based on feedback from heikki.krogerus@linux.intel.com
- self_powered added to the struct tcpm_port which is populated from
  a. "connector" node of the device tree in tcpm_fw_get_caps()
  b. "self_powered" node of the tcpc_config in tcpm_copy_caps

Based on feedbase from linux@roeck-us.net
- Code was refactored
- SRC_HARD_RESET_VBUS_OFF sets the link state to false based
  on self_powered flag

V1 located here:
https://lkml.org/lkml/2018/9/13/94
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-07 13:20:39 +01:00
..
altmodes usb: typec: unlock dp->lock on error exit path, and also zero ret if successful 2018-07-06 16:36:19 +02:00
mux usb: typec: pi3usb30532: Start using generic state values 2018-07-02 17:42:36 +02:00
tcpm usb: typec: tcpm: Do not disconnect link for self powered devices 2018-11-07 13:20:39 +01:00
ucsi usb: typec: ucsi: Fix for incorrect status data issue 2018-06-25 21:30:12 +08:00
bus.c usb/typec: fix kernel-doc notation warning for typec_match_altmode 2018-09-05 14:36:53 +02:00
bus.h usb: typec: avoid format-overflow warning 2018-07-06 16:36:19 +02:00
class.c usb: typec: Fix copy/paste on typec_set_vconn_role() kerneldoc 2018-10-09 16:05:41 +02:00
Kconfig usb: typec: Group all TCPCI/TCPM code together 2018-09-20 13:37:29 +02:00
Makefile usb: typec: Group all TCPCI/TCPM code together 2018-09-20 13:37:29 +02:00
mux.c usb: typec: mux: Take care of driver module reference counting 2018-09-20 13:35:01 +02:00
tps6598x.c usb: typec: tps6598x: Remove VLA usage 2018-06-28 19:49:46 +09:00