[PATCH linux dev-6.6 v2] usb: typec: tcpm: Add support for parsing pd-revision DT property

[Cosmo Chou]

From: Amit Sunil Dhamne <amitsd at google.com>

Add support for parsing "pd-revision" DT property in TCPM and store PD
revision and version supported by the Type-C connnector.

It should be noted that the PD revision is the maximum possible revision
supported by the port. This is different from the 2 bit revision set in
PD msg headers. The purpose of the 2 bit revision value is to negotiate
between Rev 2.X & 3.X spec rev as part of contract negotiation, while
this is used for Get_Revision AMS after a contract is in place.

Signed-off-by: Amit Sunil Dhamne <amitsd at google.com>
Reviewed-by: Badhri Jagan Sridharan <badhri at google.com>
Link: https://lore.kernel.org/r/20241210-get_rev_upstream-v2-2-d0094e52d48f@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[Cosmo: Resolved merge conflicts for backport]
Signed-off-by: Cosmo Chou <chou.cosmo at gmail.com>
---
 drivers/usb/typec/tcpm/tcpm.c | 47 +++++++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 790aadab72a3..bad2f002dfc8 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -296,6 +296,13 @@ struct pd_pps_data {
 	bool active;
 };
 
+struct pd_revision_info {
+	u8 rev_major;
+	u8 rev_minor;
+	u8 ver_major;
+	u8 ver_minor;
+};
+
 struct tcpm_port {
 	struct device *dev;
 
@@ -492,6 +499,9 @@ struct tcpm_port {
 	 * transitions.
 	 */
 	bool potential_contaminant;
+
+	/* Indicates maximum (revision, version) supported */
+	struct pd_revision_info pd_rev;
 #ifdef CONFIG_DEBUG_FS
 	struct dentry *dentry;
 	struct mutex logbuffer_lock;	/* log buffer access lock */
@@ -6098,7 +6108,9 @@ static void tcpm_port_unregister_pd(struct tcpm_port *port)
 
 static int tcpm_port_register_pd(struct tcpm_port *port)
 {
-	struct usb_power_delivery_desc desc = { port->typec_caps.pd_revision };
+	u16 pd_revision = port->typec_caps.pd_revision;
+	u16 pd_version = port->pd_rev.ver_major << 8 | port->pd_rev.ver_minor;
+	struct usb_power_delivery_desc desc = { pd_revision, pd_version };
 	struct usb_power_delivery_capabilities_desc caps = { };
 	struct usb_power_delivery_capabilities *cap;
 	int ret;
@@ -6270,6 +6282,29 @@ static int tcpm_fw_get_caps(struct tcpm_port *port,
 	return 0;
 }
 
+static void tcpm_fw_get_pd_revision(struct tcpm_port *port, struct fwnode_handle *fwnode)
+{
+	int ret;
+	u8 val[4];
+
+	ret = fwnode_property_count_u8(fwnode, "pd-revision");
+	if (!ret || ret != 4) {
+		tcpm_log(port, "Unable to find pd-revision property or incorrect array size");
+		return;
+	}
+
+	ret = fwnode_property_read_u8_array(fwnode, "pd-revision", val, 4);
+	if (ret) {
+		tcpm_log(port, "Failed to parse pd-revision, ret:(%d)", ret);
+		return;
+	}
+
+	port->pd_rev.rev_major = val[0];
+	port->pd_rev.rev_minor = val[1];
+	port->pd_rev.ver_major = val[2];
+	port->pd_rev.ver_minor = val[3];
+}
+
 /* Power Supply access to expose source power information */
 enum tcpm_psy_online_states {
 	TCPM_PSY_OFFLINE = 0,
@@ -6609,11 +6644,19 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc)
 	if (err < 0)
 		goto out_destroy_wq;
 
+	tcpm_fw_get_pd_revision(port, tcpc->fwnode);
+
 	port->try_role = port->typec_caps.prefer_role;
 
 	port->typec_caps.fwnode = tcpc->fwnode;
 	port->typec_caps.revision = 0x0120;	/* Type-C spec release 1.2 */
-	port->typec_caps.pd_revision = 0x0300;	/* USB-PD spec release 3.0 */
+
+	if (port->pd_rev.rev_major)
+		port->typec_caps.pd_revision = port->pd_rev.rev_major << 8 |
+					       port->pd_rev.rev_minor;
+	else
+		port->typec_caps.pd_revision = 0x0300;	/* USB-PD spec release 3.0 */
+
 	port->typec_caps.svdm_version = SVDM_VER_2_0;
 	port->typec_caps.driver_data = port;
 	port->typec_caps.ops = &tcpm_ops;
-- 
2.43.0