From b66b40ee7d0d376a725fde2b6d951a37cb3062c6 Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Mon, 30 Dec 2019 17:25:59 +0300 Subject: [PATCH] usb: typec: More API for cable handling Thunderbolt 3, and probable USB4 too, will need to be able to get details about the cables. Adding typec_cable_get() function that the alternate mode drivers can use to gain access to gain access to the cable. Signed-off-by: Heikki Krogerus Link: https://lore.kernel.org/r/20191230142611.24921-4-heikki.krogerus@linux.intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/typec/class.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/usb/typec.h | 4 ++++ 2 files changed, 50 insertions(+) diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c index 91d6227..0892363 100644 --- a/drivers/usb/typec/class.c +++ b/drivers/usb/typec/class.c @@ -834,6 +834,52 @@ static const struct device_type typec_cable_dev_type = { .release = typec_cable_release, }; +static int cable_match(struct device *dev, void *data) +{ + return is_typec_cable(dev); +} + +/** + * typec_cable_get - Get a reference to the USB Type-C cable + * @port: The USB Type-C Port the cable is connected to + * + * The caller must decrement the reference count with typec_cable_put() after + * use. + */ +struct typec_cable *typec_cable_get(struct typec_port *port) +{ + struct device *dev; + + dev = device_find_child(&port->dev, NULL, cable_match); + if (!dev) + return NULL; + + return to_typec_cable(dev); +} +EXPORT_SYMBOL_GPL(typec_cable_get); + +/** + * typec_cable_get - Decrement the reference count on USB Type-C cable + * @cable: The USB Type-C cable + */ +void typec_cable_put(struct typec_cable *cable) +{ + put_device(&cable->dev); +} +EXPORT_SYMBOL_GPL(typec_cable_put); + +/** + * typec_cable_is_active - Check is the USB Type-C cable active or passive + * @cable: The USB Type-C Cable + * + * Return 1 if the cable is active or 0 if it's passive. + */ +int typec_cable_is_active(struct typec_cable *cable) +{ + return cable->active; +} +EXPORT_SYMBOL_GPL(typec_cable_is_active); + /** * typec_cable_set_identity - Report result from Discover Identity command * @cable: The cable updated identity values diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h index 0f52723..d95ea0d 100644 --- a/include/linux/usb/typec.h +++ b/include/linux/usb/typec.h @@ -230,6 +230,10 @@ struct typec_cable *typec_register_cable(struct typec_port *port, struct typec_cable_desc *desc); void typec_unregister_cable(struct typec_cable *cable); +struct typec_cable *typec_cable_get(struct typec_port *port); +void typec_cable_put(struct typec_cable *cable); +int typec_cable_is_active(struct typec_cable *cable); + struct typec_plug *typec_register_plug(struct typec_cable *cable, struct typec_plug_desc *desc); void typec_unregister_plug(struct typec_plug *plug); -- 2.7.4