From 20936f77347d021299301569603b317c110de712 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 30 Sep 2020 16:28:49 +0200 Subject: media: v4l2-fwnode: Rework v4l2_fwnode_endpoint_parse documentation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rework the documentation of v4l2_fwnode_endpoint_parse for better readability, usefulness and correctness. Signed-off-by: Sakari Ailus Reviewed-by: Niklas Söderlund Reviewed-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- include/media/v4l2-fwnode.h | 62 +++++++++++++++++++++++++++++---------------- 1 file changed, 40 insertions(+), 22 deletions(-) (limited to 'include/media/v4l2-fwnode.h') diff --git a/include/media/v4l2-fwnode.h b/include/media/v4l2-fwnode.h index ed0840f3d5df..20b30d770944 100644 --- a/include/media/v4l2-fwnode.h +++ b/include/media/v4l2-fwnode.h @@ -219,17 +219,26 @@ struct v4l2_fwnode_connector { * @vep: pointer to the V4L2 fwnode data structure * * This function parses the V4L2 fwnode endpoint specific parameters from the - * firmware. The caller is responsible for assigning @vep.bus_type to a valid - * media bus type. The caller may also set the default configuration for the - * endpoint --- a configuration that shall be in line with the DT binding - * documentation. Should a device support multiple bus types, the caller may - * call this function once the correct type is found --- with a default - * configuration valid for that type. - * - * It is also allowed to set @vep.bus_type to V4L2_MBUS_UNKNOWN. USING THIS - * FEATURE REQUIRES "bus-type" PROPERTY IN DT BINDINGS. For old drivers, - * guessing @vep.bus_type between CSI-2 D-PHY, parallel and BT.656 busses is - * supported. NEVER RELY ON GUESSING @vep.bus_type IN NEW DRIVERS! + * firmware. There are two ways to use this function, either by letting it + * obtain the type of the bus (by setting the @vep.bus_type field to + * V4L2_MBUS_UNKNOWN) or specifying the bus type explicitly to one of the &enum + * v4l2_mbus_type types. + * + * When @vep.bus_type is V4L2_MBUS_UNKNOWN, the function will use the "bus-type" + * property to determine the type when it is available. The caller is + * responsible for validating the contents of @vep.bus_type field after the call + * returns. + * + * As a deprecated functionality to support older DT bindings without "bus-type" + * property for devices that support multiple types, if the "bus-type" property + * does not exist, the function will attempt to guess the type based on the + * endpoint properties available. NEVER RELY ON GUESSING THE BUS TYPE IN NEW + * DRIVERS OR BINDINGS. + * + * It is also possible to set @vep.bus_type corresponding to an actual bus. In + * this case the function will only attempt to parse properties related to this + * bus, and it will return an error if the value of the "bus-type" property + * corresponds to a different bus. * * The caller is required to initialise all fields of @vep, either with * explicitly values, or by zeroing them. @@ -264,17 +273,26 @@ void v4l2_fwnode_endpoint_free(struct v4l2_fwnode_endpoint *vep); * @vep: pointer to the V4L2 fwnode data structure * * This function parses the V4L2 fwnode endpoint specific parameters from the - * firmware. The caller is responsible for assigning @vep.bus_type to a valid - * media bus type. The caller may also set the default configuration for the - * endpoint --- a configuration that shall be in line with the DT binding - * documentation. Should a device support multiple bus types, the caller may - * call this function once the correct type is found --- with a default - * configuration valid for that type. - * - * It is also allowed to set @vep.bus_type to V4L2_MBUS_UNKNOWN. USING THIS - * FEATURE REQUIRES "bus-type" PROPERTY IN DT BINDINGS. For old drivers, - * guessing @vep.bus_type between CSI-2 D-PHY, parallel and BT.656 busses is - * supported. NEVER RELY ON GUESSING @vep.bus_type IN NEW DRIVERS! + * firmware. There are two ways to use this function, either by letting it + * obtain the type of the bus (by setting the @vep.bus_type field to + * V4L2_MBUS_UNKNOWN) or specifying the bus type explicitly to one of the &enum + * v4l2_mbus_type types. + * + * When @vep.bus_type is V4L2_MBUS_UNKNOWN, the function will use the "bus-type" + * property to determine the type when it is available. The caller is + * responsible for validating the contents of @vep.bus_type field after the call + * returns. + * + * As a deprecated functionality to support older DT bindings without "bus-type" + * property for devices that support multiple types, if the "bus-type" property + * does not exist, the function will attempt to guess the type based on the + * endpoint properties available. NEVER RELY ON GUESSING THE BUS TYPE IN NEW + * DRIVERS OR BINDINGS. + * + * It is also possible to set @vep.bus_type corresponding to an actual bus. In + * this case the function will only attempt to parse properties related to this + * bus, and it will return an error if the value of the "bus-type" property + * corresponds to a different bus. * * The caller is required to initialise all fields of @vep, either with * explicitly values, or by zeroing them. -- cgit v1.2.3-59-g8ed1b