From 131c7d12ef21e16697098b282f65fcf20792eafe Mon Sep 17 00:00:00 2001
From: Badhri Jagan Sridharan <badhri@google.com>
Date: Mon, 28 Aug 2017 10:23:16 -0700
Subject: [PATCH] staging: typec: tcpm: Follow Try.SRC exit requirements
Git-commit: 131c7d12ef21e16697098b282f65fcf20792eafe
References: FATE#326325
Patch-mainline: v4.14

According to spec:
" 4.5.2.2.9.2 Exiting from Try.SRC State:
The port shall transition to Attached.SRC when the SRC.Rd
state is detected on exactly one of the CC1 or CC2 pins for
at least tPDDebounce. The port shall transition to
TryWait.SNK after tDRPTry and the SRC.Rd state has not been
detected."

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/staging/typec/tcpm.c | 33 ++++++++++++++++++++++++++++-----
 1 file changed, 28 insertions(+), 5 deletions(-)

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index 9058488d1ac9..6afd9a8fbde2 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -112,6 +112,7 @@
 	S(SRC_TRYWAIT_UNATTACHED),		\
 						\
 	S(SRC_TRY),				\
+	S(SRC_TRY_WAIT),                        \
 	S(SRC_TRY_DEBOUNCE),			\
 	S(SNK_TRYWAIT),				\
 	S(SNK_TRYWAIT_DEBOUNCE),		\
@@ -2163,6 +2164,7 @@ static void run_state_machine(struct tcpm_port *port)
 {
 	int ret;
 	enum typec_pwr_opmode opmode;
+	unsigned int msecs;
 
 	port->enter_state = port->state;
 	switch (port->state) {
@@ -2384,7 +2386,22 @@ static void run_state_machine(struct tcpm_port *port)
 	case SRC_TRY:
 		port->try_src_count++;
 		tcpm_set_cc(port, tcpm_rp_cc(port));
-		tcpm_set_state(port, SNK_TRYWAIT, PD_T_DRP_TRY);
+		port->max_wait = 0;
+		tcpm_set_state(port, SRC_TRY_WAIT, 0);
+		break;
+	case SRC_TRY_WAIT:
+		if (port->max_wait == 0) {
+			port->max_wait = jiffies +
+					 msecs_to_jiffies(PD_T_DRP_TRY);
+			msecs = PD_T_DRP_TRY;
+		} else {
+			if (time_is_after_jiffies(port->max_wait))
+				msecs = jiffies_to_msecs(port->max_wait -
+							 jiffies);
+			else
+				msecs = 0;
+		}
+		tcpm_set_state(port, SNK_TRYWAIT, msecs);
 		break;
 	case SRC_TRY_DEBOUNCE:
 		tcpm_set_state(port, SRC_ATTACHED, PD_T_PD_DEBOUNCE);
@@ -2940,12 +2957,12 @@ static void _tcpm_cc_change(struct tcpm_port *port, enum typec_cc_status cc1,
 			tcpm_set_state(port, SRC_TRYWAIT, 0);
 		}
 		break;
-	case SRC_TRY:
+	case SRC_TRY_WAIT:
 		if (tcpm_port_is_source(port))
 			tcpm_set_state(port, SRC_TRY_DEBOUNCE, 0);
 		break;
 	case SRC_TRY_DEBOUNCE:
-		tcpm_set_state(port, SRC_TRY, 0);
+		tcpm_set_state(port, SRC_TRY_WAIT, 0);
 		break;
 	case SNK_TRYWAIT_DEBOUNCE:
 		if (port->vbus_present) {
@@ -3020,7 +3037,10 @@ static void _tcpm_pd_vbus_on(struct tcpm_port *port)
 	case SNK_TRYWAIT:
 		tcpm_set_state(port, SNK_TRYWAIT_VBUS, 0);
 		break;
-
+	case SRC_TRY_WAIT:
+	case SRC_TRY_DEBOUNCE:
+		/* Do nothing, waiting for sink detection */
+		break;
 	default:
 		break;
 	}
@@ -3074,7 +3094,10 @@ static void _tcpm_pd_vbus_off(struct tcpm_port *port)
 	case PORT_RESET_WAIT_OFF:
 		tcpm_set_state(port, tcpm_default_state(port), 0);
 		break;
-
+	case SRC_TRY_WAIT:
+	case SRC_TRY_DEBOUNCE:
+		/* Do nothing, waiting for sink detection */
+		break;
 	default:
 		if (port->pwr_role == TYPEC_SINK &&
 		    port->attached)
-- 
2.16.4