From 157c0f2f641a9938382b092c64548ebdabfe25e0 Mon Sep 17 00:00:00 2001
From: Badhri Jagan Sridharan <badhri@google.com>
Date: Mon, 1 Oct 2018 12:45:01 -0700
Subject: [PATCH] usb: typec: tcpm: charge current handling for sink during
 hard reset
Git-commit: 157c0f2f641a9938382b092c64548ebdabfe25e0
Patch-mainline: v5.0-rc1
References: FATE#326325

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: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/typec/tcpm/tcpm.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -3258,7 +3258,8 @@ static void run_state_machine(struct tcp
 	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, false, TYPEC_SINK, TYPEC_DEVICE);
 		/*
 		 * VBUS may or may not toggle, depending on the adapter.
@@ -3289,6 +3290,12 @@ static void run_state_machine(struct tcp
 		 * 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;