From 2458eba821c1fde3181e2674030509538bf4bf13 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 28 Dec 2005 12:56:04 +0000 Subject: Added some comments about multiple tuner support. - Added some comments to make clearer how to use ioctl api to handle multiple tuners at the same board. Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- linux/include/media/tuner.h | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) (limited to 'linux') diff --git a/linux/include/media/tuner.h b/linux/include/media/tuner.h index 454712340..afa302fec 100644 --- a/linux/include/media/tuner.h +++ b/linux/include/media/tuner.h @@ -1,5 +1,5 @@ /* - $Id: tuner.h,v 1.68 2005/12/20 07:53:13 mkrufky Exp $ + $Id: tuner.h,v 1.69 2005/12/28 12:56:04 mchehab Exp $ tuner.h - definition for different tuners Copyright (C) 1997 Markus Schroeder (schroedm@uni-duesseldorf.de) @@ -151,10 +151,26 @@ enum tuner_mode { T_STANDBY = 1 << 31 }; +/* Older boards only had a single tuner device. Nowadays multiple tuner + devices may be present on a single board. Using TUNER_SET_TYPE_ADDR + to pass the tuner_setup structure it is possible to setup each tuner + device in turn. + + Since multiple devices may be present it is no longer sufficient to + send a command to a single i2c device. Instead you should broadcast + the command to all i2c devices. + + By setting the mode_mask correctly you can select which commands are + accepted by a specific tuner device. For example, set mode_mask to + T_RADIO if the device is a radio-only tuner. That specific tuner will + only accept commands when the tuner is in radio mode and ignore them + when the tuner is set to TV mode. + */ + struct tuner_setup { - unsigned short addr; - unsigned int type; - unsigned int mode_mask; + unsigned short addr; /* I2C address */ + unsigned int type; /* Tuner type */ + unsigned int mode_mask; /* Allowed tuner modes */ }; struct tuner { -- cgit v1.2.3