kernel-fxtec-pro1x/drivers/media/usb/stk1160/stk1160-ac97.c
Dan Carpenter 0590c7130d [media] stk1160: remove unneeded check
"card" is a valid pointer here because we checked snd_card_create() for
error returns.  Checking after a dereference makes the static checkers
complain.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ezequiel Garcia <elezegarcia@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-08-15 18:53:29 -03:00

152 lines
3.9 KiB
C

/*
* STK1160 driver
*
* Copyright (C) 2012 Ezequiel Garcia
* <elezegarcia--a.t--gmail.com>
*
* Based on Easycap driver by R.M. Thomas
* Copyright (C) 2010 R.M. Thomas
* <rmthomas--a.t--sciolus.org>
*
* 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.
*
*/
#include <linux/module.h>
#include <sound/core.h>
#include <sound/initval.h>
#include <sound/ac97_codec.h>
#include "stk1160.h"
#include "stk1160-reg.h"
static struct snd_ac97 *stk1160_ac97;
static void stk1160_write_ac97(struct snd_ac97 *ac97, u16 reg, u16 value)
{
struct stk1160 *dev = ac97->private_data;
/* Set codec register address */
stk1160_write_reg(dev, STK1160_AC97_ADDR, reg);
/* Set codec command */
stk1160_write_reg(dev, STK1160_AC97_CMD, value & 0xff);
stk1160_write_reg(dev, STK1160_AC97_CMD + 1, (value & 0xff00) >> 8);
/*
* Set command write bit to initiate write operation.
* The bit will be cleared when transfer is done.
*/
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8c);
}
static u16 stk1160_read_ac97(struct snd_ac97 *ac97, u16 reg)
{
struct stk1160 *dev = ac97->private_data;
u8 vall = 0;
u8 valh = 0;
/* Set codec register address */
stk1160_write_reg(dev, STK1160_AC97_ADDR, reg);
/*
* Set command read bit to initiate read operation.
* The bit will be cleared when transfer is done.
*/
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x8b);
/* Retrieve register value */
stk1160_read_reg(dev, STK1160_AC97_CMD, &vall);
stk1160_read_reg(dev, STK1160_AC97_CMD + 1, &valh);
return (valh << 8) | vall;
}
static void stk1160_reset_ac97(struct snd_ac97 *ac97)
{
struct stk1160 *dev = ac97->private_data;
/* Two-step reset AC97 interface and hardware codec */
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x94);
stk1160_write_reg(dev, STK1160_AC97CTL_0, 0x88);
/* Set 16-bit audio data and choose L&R channel*/
stk1160_write_reg(dev, STK1160_AC97CTL_1 + 2, 0x01);
}
static struct snd_ac97_bus_ops stk1160_ac97_ops = {
.read = stk1160_read_ac97,
.write = stk1160_write_ac97,
.reset = stk1160_reset_ac97,
};
int stk1160_ac97_register(struct stk1160 *dev)
{
struct snd_card *card = NULL;
struct snd_ac97_bus *ac97_bus;
struct snd_ac97_template ac97_template;
int rc;
/*
* Just want a card to access ac96 controls,
* the actual capture interface will be handled by snd-usb-audio
*/
rc = snd_card_create(SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
THIS_MODULE, 0, &card);
if (rc < 0)
return rc;
snd_card_set_dev(card, dev->dev);
/* TODO: I'm not sure where should I get these names :-( */
snprintf(card->shortname, sizeof(card->shortname),
"stk1160-mixer");
snprintf(card->longname, sizeof(card->longname),
"stk1160 ac97 codec mixer control");
strncpy(card->driver, dev->dev->driver->name, sizeof(card->driver));
rc = snd_ac97_bus(card, 0, &stk1160_ac97_ops, NULL, &ac97_bus);
if (rc)
goto err;
/* We must set private_data before calling snd_ac97_mixer */
memset(&ac97_template, 0, sizeof(ac97_template));
ac97_template.private_data = dev;
ac97_template.scaps = AC97_SCAP_SKIP_MODEM;
rc = snd_ac97_mixer(ac97_bus, &ac97_template, &stk1160_ac97);
if (rc)
goto err;
dev->snd_card = card;
rc = snd_card_register(card);
if (rc)
goto err;
return 0;
err:
dev->snd_card = NULL;
snd_card_free(card);
return rc;
}
int stk1160_ac97_unregister(struct stk1160 *dev)
{
struct snd_card *card = dev->snd_card;
/*
* We need to check usb_device,
* because ac97 release attempts to communicate with codec
*/
if (card && dev->udev)
snd_card_free(card);
return 0;
}