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linux-next/drivers/media/video/cx18/cx18-audio.c
Andy Walls 33b55a0a7d V4L/DVB (11624): cx18: Toggle the AI1 mux when changing the CX18_AUDIO_ENABLE register
Toggle the AI1 mux when changing the CX18_AUDIO_ENABLE register.  It's hard to
reliably tell when we have written to this register successfully unless we
change some bits we know we can read back.  The AI mux bits always read back
what we wrote to them, so force them to toggle whenever we have to write to
the register, so we can tell we wrote to the register successfully.

This change was prompted by users experiencing broadcast audio decoding
problems after the cx18 module loads for the first time.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2009-06-16 18:20:45 -03:00

93 lines
2.5 KiB
C

/*
* cx18 audio-related functions
*
* Derived from ivtv-audio.c
*
* Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
*
* 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, or
* (at your option) any later version.
*
* 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
*/
#include "cx18-driver.h"
#include "cx18-io.h"
#include "cx18-cards.h"
#include "cx18-audio.h"
#define CX18_AUDIO_ENABLE 0xc72014
#define CX18_AI1_MUX_MASK 0x30
#define CX18_AI1_MUX_I2S1 0x00
#define CX18_AI1_MUX_I2S2 0x10
#define CX18_AI1_MUX_843_I2S 0x20
/* Selects the audio input and output according to the current
settings. */
int cx18_audio_set_io(struct cx18 *cx)
{
const struct cx18_card_audio_input *in;
u32 u, v;
int err;
/* Determine which input to use */
if (test_bit(CX18_F_I_RADIO_USER, &cx->i_flags))
in = &cx->card->radio_input;
else
in = &cx->card->audio_inputs[cx->audio_input];
/* handle muxer chips */
v4l2_subdev_call(cx->sd_extmux, audio, s_routing,
(u32) in->muxer_input, 0, 0);
err = cx18_call_hw_err(cx, cx->card->hw_audio_ctrl,
audio, s_routing, in->audio_input, 0, 0);
if (err)
return err;
/* FIXME - this internal mux should be abstracted to a subdev */
u = cx18_read_reg(cx, CX18_AUDIO_ENABLE);
v = u & ~CX18_AI1_MUX_MASK;
switch (in->audio_input) {
case CX18_AV_AUDIO_SERIAL1:
v |= CX18_AI1_MUX_I2S1;
break;
case CX18_AV_AUDIO_SERIAL2:
v |= CX18_AI1_MUX_I2S2;
break;
default:
v |= CX18_AI1_MUX_843_I2S;
break;
}
if (v == u) {
/* force a toggle of some AI1 MUX control bits */
u &= ~CX18_AI1_MUX_MASK;
switch (in->audio_input) {
case CX18_AV_AUDIO_SERIAL1:
u |= CX18_AI1_MUX_843_I2S;
break;
case CX18_AV_AUDIO_SERIAL2:
u |= CX18_AI1_MUX_843_I2S;
break;
default:
u |= CX18_AI1_MUX_I2S1;
break;
}
cx18_write_reg_expect(cx, u | 0xb00, CX18_AUDIO_ENABLE,
u, CX18_AI1_MUX_MASK);
}
cx18_write_reg_expect(cx, v | 0xb00, CX18_AUDIO_ENABLE,
v, CX18_AI1_MUX_MASK);
return 0;
}