linux-kernel - [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

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Message-ID: <20250513130834.1612602-1-chou.cosmo@gmail.com>
Date: Tue, 13 May 2025 21:08:34 +0800
From: Cosmo Chou <chou.cosmo@...il.com>
To: badhri@...gle.com,
	heikki.krogerus@...ux.intel.com,
	gregkh@...uxfoundation.org
Cc: linux-usb@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	chou.cosmo@...il.com,
	cosmo.chou@...ntatw.com
Subject: [PATCH v2] usb: typec: tcpm: Use configured PD revision for negotiation

Initialize negotiated_rev and negotiated_rev_prime based on the port's
configured PD revision (rev_major) rather than always defaulting to
PD_MAX_REV. This ensures ports start PD communication using their
appropriate revision level.

This allows proper communication with devices that require specific
PD revision levels, especially for the hardware designed for PD 1.0
or 2.0 specifications.

Signed-off-by: Cosmo Chou <chou.cosmo@...il.com>
---
Change log:

v2:
  - Add PD_CAP_REVXX macros and use switch-case for better readability.

---
 drivers/usb/typec/tcpm/tcpm.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 8adf6f954633..48e9cfc2b49a 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -313,6 +313,10 @@ struct pd_data {
 	unsigned int operating_snk_mw;
 };
 
+#define PD_CAP_REV10	0x1
+#define PD_CAP_REV20	0x2
+#define PD_CAP_REV30	0x3
+
 struct pd_revision_info {
 	u8 rev_major;
 	u8 rev_minor;
@@ -4665,6 +4669,25 @@ static void tcpm_set_initial_svdm_version(struct tcpm_port *port)
 	}
 }
 
+static void tcpm_set_initial_negotiated_rev(struct tcpm_port *port)
+{
+	switch (port->pd_rev.rev_major) {
+	case PD_CAP_REV10:
+		port->negotiated_rev = PD_REV10;
+		break;
+	case PD_CAP_REV20:
+		port->negotiated_rev = PD_REV20;
+		break;
+	case PD_CAP_REV30:
+		port->negotiated_rev = PD_REV30;
+		break;
+	default:
+		port->negotiated_rev = PD_MAX_REV;
+		break;
+	}
+	port->negotiated_rev_prime = port->negotiated_rev;
+}
+
 static void run_state_machine(struct tcpm_port *port)
 {
 	int ret;
@@ -4782,8 +4805,7 @@ static void run_state_machine(struct tcpm_port *port)
 		typec_set_pwr_opmode(port->typec_port, opmode);
 		port->pwr_opmode = TYPEC_PWR_MODE_USB;
 		port->caps_count = 0;
-		port->negotiated_rev = PD_MAX_REV;
-		port->negotiated_rev_prime = PD_MAX_REV;
+		tcpm_set_initial_negotiated_rev(port);
 		port->message_id = 0;
 		port->message_id_prime = 0;
 		port->rx_msgid = -1;
@@ -5048,8 +5070,7 @@ static void run_state_machine(struct tcpm_port *port)
 					      port->cc2 : port->cc1);
 		typec_set_pwr_opmode(port->typec_port, opmode);
 		port->pwr_opmode = TYPEC_PWR_MODE_USB;
-		port->negotiated_rev = PD_MAX_REV;
-		port->negotiated_rev_prime = PD_MAX_REV;
+		tcpm_set_initial_negotiated_rev(port);
 		port->message_id = 0;
 		port->message_id_prime = 0;
 		port->rx_msgid = -1;
-- 
2.43.0