diff options
Diffstat (limited to 'drivers/media/usb/stk1160/stk1160-ac97.c')
| -rw-r--r-- | drivers/media/usb/stk1160/stk1160-ac97.c | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/drivers/media/usb/stk1160/stk1160-ac97.c b/drivers/media/usb/stk1160/stk1160-ac97.c new file mode 100644 index 0000000..c8583c2 --- /dev/null +++ b/drivers/media/usb/stk1160/stk1160-ac97.c @@ -0,0 +1,152 @@ +/* + * 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; +} |