usb: typec: altmodes: add typec_cable_ops to typec_altmode

Add typec_cable_ops struct for enter, exit, and vdm. The struct is added
to typec_altmode so port alt modes can have access to partner and cable
specific callbacks, and alt mode drivers can specify operations over SOP'
and SOP'' without modifying the existing API.

typec_port_register_cable_ops is added as a new symbol for port drivers
to use to register cable operations to their registered port alt modes.

Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240108191620.987785-15-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

4 files changed, 145 insertions, 0 deletions

diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c
index e95ec7e382bb..6ea103e1abae 100644
--- a/drivers/usb/typec/bus.c
+++ b/drivers/usb/typec/bus.c
@@ -245,6 +245,108 @@ typec_altmode_get_partner(struct typec_altmode *adev)
 EXPORT_SYMBOL_GPL(typec_altmode_get_partner);
 
 /* -------------------------------------------------------------------------- */
+/* API for cable alternate modes */
+
+/**
+ * typec_cable_altmode_enter - Enter Mode
+ * @adev: The alternate mode
+ * @sop: Cable plug target for Enter Mode command
+ * @vdo: VDO for the Enter Mode command
+ *
+ * Alternate mode drivers use this function to enter mode on the cable plug.
+ * If the alternate mode does not require VDO, @vdo must be NULL.
+ */
+int typec_cable_altmode_enter(struct typec_altmode *adev, enum typec_plug_index sop, u32 *vdo)
+{
+	struct altmode *partner = to_altmode(adev)->partner;
+	struct typec_altmode *pdev;
+
+	if (!adev || adev->active)
+		return 0;
+
+	if (!partner)
+		return -ENODEV;
+
+	pdev = &partner->adev;
+
+	if (!pdev->active)
+		return -EPERM;
+
+	if (!pdev->cable_ops || !pdev->cable_ops->enter)
+		return -EOPNOTSUPP;
+
+	return pdev->cable_ops->enter(pdev, sop, vdo);
+}
+EXPORT_SYMBOL_GPL(typec_cable_altmode_enter);
+
+/**
+ * typec_cable_altmode_exit - Exit Mode
+ * @adev: The alternate mode
+ * @sop: Cable plug target for Exit Mode command
+ *
+ * The alternate mode drivers use this function to exit mode on the cable plug.
+ */
+int typec_cable_altmode_exit(struct typec_altmode *adev, enum typec_plug_index sop)
+{
+	struct altmode *partner = to_altmode(adev)->partner;
+	struct typec_altmode *pdev;
+
+	if (!adev || !adev->active)
+		return 0;
+
+	if (!partner)
+		return -ENODEV;
+
+	pdev = &partner->adev;
+
+	if (!pdev->cable_ops || !pdev->cable_ops->exit)
+		return -EOPNOTSUPP;
+
+	return pdev->cable_ops->exit(pdev, sop);
+}
+EXPORT_SYMBOL_GPL(typec_cable_altmode_exit);
+
+/**
+ * typec_cable_altmode_vdm - Send Vendor Defined Messages (VDM) between the cable plug and port.
+ * @adev: Alternate mode handle
+ * @sop: Cable plug target for VDM
+ * @header: VDM Header
+ * @vdo: Array of Vendor Defined Data Objects
+ * @count: Number of Data Objects
+ *
+ * The alternate mode drivers use this function for SVID specific communication
+ * with the cable plugs. The port drivers use it to deliver the Structured VDMs
+ * received from the cable plugs to the alternate mode drivers.
+ */
+int typec_cable_altmode_vdm(struct typec_altmode *adev, enum typec_plug_index sop,
+			    const u32 header, const u32 *vdo, int count)
+{
+	struct altmode *altmode;
+	struct typec_altmode *pdev;
+
+	if (!adev)
+		return 0;
+
+	altmode = to_altmode(adev);
+
+	if (is_typec_plug(adev->dev.parent)) {
+		if (!altmode->partner)
+			return -ENODEV;
+		pdev = &altmode->partner->adev;
+	} else {
+		if (!altmode->plug[sop])
+			return -ENODEV;
+		pdev = &altmode->plug[sop]->adev;
+	}
+
+	if (!pdev->cable_ops || !pdev->cable_ops->vdm)
+		return -EOPNOTSUPP;
+
+	return pdev->cable_ops->vdm(pdev, sop, header, vdo, count);
+}
+EXPORT_SYMBOL_GPL(typec_cable_altmode_vdm);
+
+/* -------------------------------------------------------------------------- */
 /* API for the alternate mode drivers */
 
 /**
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 015aa9253353..8fc9795d6bd4 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -2281,6 +2281,25 @@ void typec_port_register_altmodes(struct typec_port *port,
 EXPORT_SYMBOL_GPL(typec_port_register_altmodes);
 
 /**
+ * typec_port_register_cable_ops - Register typec_cable_ops to port altmodes
+ * @altmodes: USB Type-C Port's altmode vector
+ * @max_altmodes: The maximum number of alt modes supported by the port
+ * @ops: Cable alternate mode vector
+ */
+void typec_port_register_cable_ops(struct typec_altmode **altmodes, int max_altmodes,
+				   const struct typec_cable_ops *ops)
+{
+	int i;
+
+	for (i = 0; i < max_altmodes; i++) {
+		if (!altmodes[i])
+			return;
+		altmodes[i]->cable_ops = ops;
+	}
+}
+EXPORT_SYMBOL_GPL(typec_port_register_cable_ops);
+
+/**
  * typec_register_port - Register a USB Type-C Port
  * @parent: Parent device
  * @cap: Description of the port
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index a05d6f6f2536..38f93d72fd1b 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -18,6 +18,7 @@ struct typec_cable;
 struct typec_plug;
 struct typec_port;
 struct typec_altmode_ops;
+struct typec_cable_ops;
 
 struct fwnode_handle;
 struct device;
@@ -157,6 +158,9 @@ void typec_port_register_altmodes(struct typec_port *port,
 	const struct typec_altmode_ops *ops, void *drvdata,
 	struct typec_altmode **altmodes, size_t n);
 
+void typec_port_register_cable_ops(struct typec_altmode **altmodes, int max_altmodes,
+				   const struct typec_cable_ops *ops);
+
 void typec_unregister_altmode(struct typec_altmode *altmode);
 
 struct typec_port *typec_altmode2port(struct typec_altmode *alt);
diff --git a/include/linux/usb/typec_altmode.h b/include/linux/usb/typec_altmode.h
index 28aeef8f9e7b..72ec8058543a 100644
--- a/include/linux/usb/typec_altmode.h
+++ b/include/linux/usb/typec_altmode.h
@@ -20,6 +20,7 @@ struct typec_altmode_ops;
  * @active: Tells has the mode been entered or not
  * @desc: Optional human readable description of the mode
  * @ops: Operations vector from the driver
+ * @cable_ops: Cable operations vector from the driver.
  */
 struct typec_altmode {
 	struct device			dev;
@@ -30,6 +31,7 @@ struct typec_altmode {
 
 	char				*desc;
 	const struct typec_altmode_ops	*ops;
+	const struct typec_cable_ops	*cable_ops;
 };
 
 #define to_typec_altmode(d) container_of(d, struct typec_altmode, dev)
@@ -75,6 +77,24 @@ int typec_altmode_notify(struct typec_altmode *altmode, unsigned long conf,
 const struct typec_altmode *
 typec_altmode_get_partner(struct typec_altmode *altmode);
 
+/**
+ * struct typec_cable_ops - Cable alternate mode operations vector
+ * @enter: Operations to be executed with Enter Mode Command
+ * @exit: Operations to be executed with Exit Mode Command
+ * @vdm: Callback for SVID specific commands
+ */
+struct typec_cable_ops {
+	int (*enter)(struct typec_altmode *altmode, enum typec_plug_index sop, u32 *vdo);
+	int (*exit)(struct typec_altmode *altmode, enum typec_plug_index sop);
+	int (*vdm)(struct typec_altmode *altmode, enum typec_plug_index sop,
+		   const u32 hdr, const u32 *vdo, int cnt);
+};
+
+int typec_cable_altmode_enter(struct typec_altmode *altmode, enum typec_plug_index sop, u32 *vdo);
+int typec_cable_altmode_exit(struct typec_altmode *altmode, enum typec_plug_index sop);
+int typec_cable_altmode_vdm(struct typec_altmode *altmode, enum typec_plug_index sop,
+			    const u32 header, const u32 *vdo, int count);
+
 /*
  * These are the connector states (USB, Safe and Alt Mode) defined in USB Type-C
  * Specification. SVID specific connector states are expected to follow and