android_kernel_xiaomi_sm8350/drivers/media/video/pvrusb2/pvrusb2-i2c-cmd-v4l2.h
Pantelis Koukousoulas 275b2e283b V4L/DVB (5034): Pvrusb2: Enable radio mode round #1
This is the logic that supports switching modes via e.g.,
  echo radio > /sys/class/pvrusb2/sn-*/ctl_input/cur_val.

To do the mode switching we need to:
a) broadcast AUDC_SET_RADIO and
b) issue the CX2341X_ENC_MUTE_VIDEO command to the encoder. 

The first is done by adding a new pvr2_i2c_op and having it trigger on 
input change, the second by adding this command in pvr2_encoder_start() 
and requesting an encoder restart on input change by setting 
stale_subsys_mask appropriately. 

The clues about AUDC_SET_RADIO and CX2341X_ENC_MUTE_VIDEO were kindly 
provided by Hans Verkuil on the pvrusb2 mailing list. The idea to 
implement mode switching this way (on input change) is due to Mike Isely.

Why AUDC_SET_RADIO/VIDIOC_S_STD are used for switching? I can 't be sure, 
but I think this can be traced to a cornell student being the first to 
implement radio support in ivtv "as a different standard". I think the 
rest just evolved from there (it 's in the ivtv ML archives).

Signed-off-by: Pantelis Koukousoulas <pakt223@freemail.gr>
Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
2007-02-21 13:34:21 -02:00

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C

/*
*
* $Id$
*
* Copyright (C) 2005 Mike Isely <isely@pobox.com>
* Copyright (C) 2004 Aurelien Alleaume <slts@free.fr>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __PVRUSB2_CMD_V4L2_H
#define __PVRUSB2_CMD_V4L2_H
#include "pvrusb2-i2c-core.h"
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_standard;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_radio;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_bcsh;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_volume;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_frequency;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_size;
extern const struct pvr2_i2c_op pvr2_i2c_op_v4l2_log;
void pvr2_v4l2_cmd_stream(struct pvr2_i2c_client *,int);
#endif /* __PVRUSB2_CMD_V4L2_H */
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