From 66f4b3cb5c2c68810772e7eee30b3d4b85852639 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Tue, 10 Nov 2015 10:46:25 -0200 Subject: [PATCH] [media] dvb_frontend: document the most used functions Documents the most used functions at the Digital TV kABI: dvb_frontend_register(), dvb_frontend_unregister() and dvb_frontend_detach(). Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-core/dvb_frontend.h | 43 +++++++++++++++++++++++++-- 1 file changed, 40 insertions(+), 3 deletions(-) diff --git a/drivers/media/dvb-core/dvb_frontend.h b/drivers/media/dvb-core/dvb_frontend.h index 7d7041a8bfea..d15507be60ff 100644 --- a/drivers/media/dvb-core/dvb_frontend.h +++ b/drivers/media/dvb-core/dvb_frontend.h @@ -687,12 +687,49 @@ struct dvb_frontend { unsigned int exit; }; -extern int dvb_register_frontend(struct dvb_adapter *dvb, +/** + * dvb_register_frontend() - Registers a DVB frontend at the adapter + * + * @dvb: pointer to the dvb adapter + * @fe: pointer to the frontend struct + * + * Allocate and initialize the private data needed by the frontend core to + * manage the frontend and calls dvb_register_device() to register a new + * frontend. It also cleans the property cache that stores the frontend + * parameters and selects the first available delivery system. + */ +int dvb_register_frontend(struct dvb_adapter *dvb, struct dvb_frontend *fe); -extern int dvb_unregister_frontend(struct dvb_frontend *fe); +/** + * dvb_unregister_frontend() - Unregisters a DVB frontend + * + * @fe: pointer to the frontend struct + * + * Stops the frontend kthread, calls dvb_unregister_device() and frees the + * private frontend data allocated by dvb_register_frontend(). + * + * NOTE: This function doesn't frees the memory allocated by the demod, + * by the SEC driver and by the tuner. In order to free it, an explicit call to + * dvb_frontend_detach() is needed, after calling this function. + */ +int dvb_unregister_frontend(struct dvb_frontend *fe); -extern void dvb_frontend_detach(struct dvb_frontend *fe); +/** + * dvb_frontend_detach() - Detaches and frees frontend specific data + * + * @fe: pointer to the frontend struct + * + * This function should be called after dvb_unregister_frontend(). It + * calls the SEC, tuner and demod release functions: + * &dvb_frontend_ops.release_sec, &dvb_frontend_ops.tuner_ops.release, + * &dvb_frontend_ops.analog_ops.release and &dvb_frontend_ops.release. + * + * If the driver is compiled with CONFIG_MEDIA_ATTACH, it also decreases + * the module reference count, needed to allow userspace to remove the + * previously used DVB frontend modules. + */ +void dvb_frontend_detach(struct dvb_frontend *fe); extern int dvb_frontend_suspend(struct dvb_frontend *fe); extern int dvb_frontend_resume(struct dvb_frontend *fe); -- 2.30.2