[PATCH AUTOSEL 4.19 215/237] usb: typec: tcpm: charge current handling for sink during hard reset

Sasha Levin
2019-11-16T16:17:18Z

From: Badhri Jagan Sridharan <badhri@google.com>

[ Upstream commit 157c0f2f641a9938382b092c64548ebdabfe25e0 ]

During the initial connect to a non-pd port, sink would hard reset
twice before deeming that the port partner is non-pd. TCPM sets the
the charge path to false during the hard reset. This causes unnecessary
connects/disconnects of charge path and makes port take longer to
charge from the non-pd ports. Avoid this by not setting the charge path
to false unless the partner has already identified to be pd capable.

When partner is a pd port, set the charge path to false in
SNK_HARD_RESET_SINK_OFF. Set the current limits to default value based
of CC pull up and resume the charge path when port enters
SNK_HARD_RESET_SINK_ON.

Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>

--------
Changes in V3:
Rebase on top of usb-next

Changes in V2:
Based on feedback of jackp@codeaurora.org
- vsafe_5v_hard_reset flag from tcpc_config is removed
- Patch only differentiates between pd port partner and non-pd port
partner

V1 version of the patch is here:
https://lkml.org/lkml/2018/9/14/11
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/typec/tcpm.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
index 819ae3b2bd7e8..39cf190012393 100644
--- a/drivers/usb/typec/tcpm.c
+++ b/drivers/usb/typec/tcpm.c
@@ -3322,7 +3322,8 @@ static void run_state_machine(struct tcpm_port *port)
case SNK_HARD_RESET_SINK_OFF:
memset(&port->pps_data, 0, sizeof(port->pps_data));
tcpm_set_vconn(port, false);
- tcpm_set_charge(port, false);
+ if (port->pd_capable)
+ tcpm_set_charge(port, false);
tcpm_set_roles(port, port->self_powered, TYPEC_SINK,
TYPEC_DEVICE);
/*
@@ -3354,6 +3355,12 @@ static void run_state_machine(struct tcpm_port *port)
* Similar, dual-mode ports in source mode should transition
* to PE_SNK_Transition_to_default.
*/
+ if (port->pd_capable) {
+ tcpm_set_current_limit(port,
+ tcpm_get_current_limit(port),
+ 5000);
+ tcpm_set_charge(port, true);
+ }
tcpm_set_attached_state(port, true);
tcpm_set_state(port, SNK_STARTUP, 0);
break;
--
2.20.1