From: Badhri Jagan Sridharan <badhri@google.com>
To: Guenter Roeck <linux@roeck-us.net>,
Heikki Krogerus <heikki.krogerus@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
Kyle Tso <kyletso@google.com>,
stable@vger.kernel.org,
Badhri Jagan Sridharan <badhri@google.com>
Subject: [PATCH v1 3/4] usb: typec: tcpm: Move TCPC to APPLY_RC state during PR_SWAP
Date: Fri, 14 May 2021 22:26:12 -0700 [thread overview]
Message-ID: <20210515052613.3261340-3-badhri@google.com> (raw)
In-Reply-To: <20210515052613.3261340-1-badhri@google.com>
When vbus auto discharge is enabled, TCPCI based TCPC transitions
into Attached.SNK/Attached.SRC state. During PR_SWAP, TCPCI based
TCPC would disconnect when partner changes power roles. TCPC has
to be moved APPLY RC state during PR_SWAP. This is done by
ROLE_CONTROL.CC1 != ROLE_CONTROL.CC2 and
POWER_CONTROL.AutodischargeDisconnect is 0. Once the swap sequence
is done, AutoDischargeDisconnect is re-enabled.
Fixes: f321a02caebd ("usb: typec: tcpm: Implement enabling Auto Discharge disconnect support")
Signed-off-by: Badhri Jagan Sridharan <badhri@google.com>
---
drivers/usb/typec/tcpm/tcpm.c | 16 ++++++++++++++++
include/linux/usb/tcpm.h | 4 ++++
2 files changed, 20 insertions(+)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index b475d9b9d38d..5bac4978efb3 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -786,6 +786,19 @@ static int tcpm_enable_auto_vbus_discharge(struct tcpm_port *port, bool enable)
return ret;
}
+static void tcpm_apply_rc(struct tcpm_port *port)
+{
+ /*
+ * TCPCI: Move to APPLY_RC state to prevent disconnect during PR_SWAP
+ * when Vbus auto discharge on disconnect is enabled.
+ */
+ if (port->tcpc->enable_auto_vbus_discharge) {
+ tcpm_log(port, "Apply_RC");
+ port->tcpc->apply_rc(port->tcpc, port->cc_req, port->polarity);
+ tcpm_enable_auto_vbus_discharge(port, false);
+ }
+}
+
/*
* Determine RP value to set based on maximum current supported
* by a port if configured as source.
@@ -4428,6 +4441,7 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, ready_state(port), 0);
break;
case PR_SWAP_START:
+ tcpm_apply_rc(port);
if (port->pwr_role == TYPEC_SOURCE)
tcpm_set_state(port, PR_SWAP_SRC_SNK_TRANSITION_OFF,
PD_T_SRC_TRANSITION);
@@ -4467,6 +4481,7 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, ERROR_RECOVERY, PD_T_PS_SOURCE_ON_PRS);
break;
case PR_SWAP_SRC_SNK_SINK_ON:
+ tcpm_enable_auto_vbus_discharge(port, true);
/* Set the vbus disconnect threshold for implicit contract */
tcpm_set_auto_vbus_discharge_threshold(port, TYPEC_PWR_MODE_USB, false, VSAFE5V);
tcpm_set_state(port, SNK_STARTUP, 0);
@@ -4483,6 +4498,7 @@ static void run_state_machine(struct tcpm_port *port)
PD_T_PS_SOURCE_OFF);
break;
case PR_SWAP_SNK_SRC_SOURCE_ON:
+ tcpm_enable_auto_vbus_discharge(port, true);
tcpm_set_cc(port, tcpm_rp_cc(port));
tcpm_set_vbus(port, true);
/*
diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h
index 42fcfbe10590..bffc8d3e14ad 100644
--- a/include/linux/usb/tcpm.h
+++ b/include/linux/usb/tcpm.h
@@ -66,6 +66,8 @@ enum tcpm_transmit_type {
* For example, some tcpcs may include BC1.2 charger detection
* and use that in this case.
* @set_cc: Called to set value of CC pins
+ * @apply_rc: Optional; Needed to move TCPCI based chipset to APPLY_RC state
+ * as stated by the TCPCI specification.
* @get_cc: Called to read current CC pin values
* @set_polarity:
* Called to set polarity
@@ -120,6 +122,8 @@ struct tcpc_dev {
int (*get_vbus)(struct tcpc_dev *dev);
int (*get_current_limit)(struct tcpc_dev *dev);
int (*set_cc)(struct tcpc_dev *dev, enum typec_cc_status cc);
+ int (*apply_rc)(struct tcpc_dev *dev, enum typec_cc_status cc,
+ enum typec_cc_polarity polarity);
int (*get_cc)(struct tcpc_dev *dev, enum typec_cc_status *cc1,
enum typec_cc_status *cc2);
int (*set_polarity)(struct tcpc_dev *dev,
--
2.31.1.751.gd2f1c929bd-goog
next prev parent reply other threads:[~2021-05-15 5:26 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-15 5:26 [PATCH v1 1/4] usb: typec: tcpm: Fix up PR_SWAP when vsafe0v is signalled Badhri Jagan Sridharan
2021-05-15 5:26 ` [PATCH v1 2/4] usb: typec: tcpm: Refactor logic to enable/disable auto vbus dicharge Badhri Jagan Sridharan
2021-05-17 14:33 ` Guenter Roeck
2021-05-15 5:26 ` Badhri Jagan Sridharan [this message]
2021-05-17 14:37 ` [PATCH v1 3/4] usb: typec: tcpm: Move TCPC to APPLY_RC state during PR_SWAP Guenter Roeck
2021-05-15 5:26 ` [PATCH v1 4/4] usb: typec: tcpci: Implement callback for apply_rc Badhri Jagan Sridharan
2021-05-17 14:38 ` Guenter Roeck
2021-05-17 1:30 ` [PATCH v1 1/4] usb: typec: tcpm: Fix up PR_SWAP when vsafe0v is signalled Peter Chen
2021-05-17 14:32 ` Guenter Roeck
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