ac97_codec.c

linux2.6.16版本

			*r_result |= SNDRV_PCM_RATE_96000;
		return;
	}

	saved = snd_ac97_read(ac97, reg);
	if ((ac97->ext_id & AC97_EI_DRA) && reg == AC97_PCM_FRONT_DAC_RATE)
		snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS,
				     AC97_EA_DRA, 0);
	/* test a non-standard rate */
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 11000))
		result |= SNDRV_PCM_RATE_CONTINUOUS;
	/* let's try to obtain standard rates */
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 8000))
		result |= SNDRV_PCM_RATE_8000;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 11025))
		result |= SNDRV_PCM_RATE_11025;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 16000))
		result |= SNDRV_PCM_RATE_16000;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 22050))
		result |= SNDRV_PCM_RATE_22050;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 32000))
		result |= SNDRV_PCM_RATE_32000;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 44100))
		result |= SNDRV_PCM_RATE_44100;
	if (snd_ac97_test_rate(ac97, reg, shadow_reg, 48000))
		result |= SNDRV_PCM_RATE_48000;
	if ((ac97->flags & AC97_DOUBLE_RATE) &&
	    reg == AC97_PCM_FRONT_DAC_RATE) {
		/* test standard double rates */
		snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS,
				     AC97_EA_DRA, AC97_EA_DRA);
		if (snd_ac97_test_rate(ac97, reg, shadow_reg, 64000 / 2))
			result |= SNDRV_PCM_RATE_64000;
		if (snd_ac97_test_rate(ac97, reg, shadow_reg, 88200 / 2))
			result |= SNDRV_PCM_RATE_88200;
		if (snd_ac97_test_rate(ac97, reg, shadow_reg, 96000 / 2))
			result |= SNDRV_PCM_RATE_96000;
		/* some codecs don't support variable double rates */
		if (!snd_ac97_test_rate(ac97, reg, shadow_reg, 76100 / 2))
			result &= ~SNDRV_PCM_RATE_CONTINUOUS;
		snd_ac97_update_bits(ac97, AC97_EXTENDED_STATUS,
				     AC97_EA_DRA, 0);
	}
	/* restore the default value */
	snd_ac97_write_cache(ac97, reg, saved);
	if (shadow_reg)
		snd_ac97_write_cache(ac97, shadow_reg, saved);
	*r_result = result;
}

/* check AC97_SPDIF register to accept which sample rates */
static unsigned int snd_ac97_determine_spdif_rates(struct snd_ac97 *ac97)
{
	unsigned int result = 0;
	int i;
	static unsigned short ctl_bits[] = {
		AC97_SC_SPSR_44K, AC97_SC_SPSR_32K, AC97_SC_SPSR_48K
	};
	static unsigned int rate_bits[] = {
		SNDRV_PCM_RATE_44100, SNDRV_PCM_RATE_32000, SNDRV_PCM_RATE_48000
	};

	for (i = 0; i < (int)ARRAY_SIZE(ctl_bits); i++) {
		snd_ac97_update_bits(ac97, AC97_SPDIF, AC97_SC_SPSR_MASK, ctl_bits[i]);
		if ((snd_ac97_read(ac97, AC97_SPDIF) & AC97_SC_SPSR_MASK) == ctl_bits[i])
			result |= rate_bits[i];
	}
	return result;
}

/* look for the codec id table matching with the given id */
static const struct ac97_codec_id *look_for_codec_id(const struct ac97_codec_id *table,
						     unsigned int id)
{
	const struct ac97_codec_id *pid;

	for (pid = table; pid->id; pid++)
		if (pid->id == (id & pid->mask))
			return pid;
	return NULL;
}

void snd_ac97_get_name(struct snd_ac97 *ac97, unsigned int id, char *name, int modem)
{
	const struct ac97_codec_id *pid;

	sprintf(name, "0x%x %c%c%c", id,
		printable(id >> 24),
		printable(id >> 16),
		printable(id >> 8));
	pid = look_for_codec_id(snd_ac97_codec_id_vendors, id);
	if (! pid)
		return;

	strcpy(name, pid->name);
	if (ac97 && pid->patch) {
		if ((modem && (pid->flags & AC97_MODEM_PATCH)) ||
		    (! modem && ! (pid->flags & AC97_MODEM_PATCH)))
			pid->patch(ac97);
	} 

	pid = look_for_codec_id(snd_ac97_codec_ids, id);
	if (pid) {
		strcat(name, " ");
		strcat(name, pid->name);
		if (pid->mask != 0xffffffff)
			sprintf(name + strlen(name), " rev %d", id & ~pid->mask);
		if (ac97 && pid->patch) {
			if ((modem && (pid->flags & AC97_MODEM_PATCH)) ||
			    (! modem && ! (pid->flags & AC97_MODEM_PATCH)))
				pid->patch(ac97);
		}
	} else
		sprintf(name + strlen(name), " id %x", id & 0xff);
}

/**
 * snd_ac97_get_short_name - retrieve codec name
 * @ac97: the codec instance
 *
 * Returns the short identifying name of the codec.
 */
const char *snd_ac97_get_short_name(struct snd_ac97 *ac97)
{
	const struct ac97_codec_id *pid;

	for (pid = snd_ac97_codec_ids; pid->id; pid++)
		if (pid->id == (ac97->id & pid->mask))
			return pid->name;
	return "unknown codec";
}


/* wait for a while until registers are accessible after RESET
 * return 0 if ok, negative not ready
 */
static int ac97_reset_wait(struct snd_ac97 *ac97, int timeout, int with_modem)
{
	unsigned long end_time;
	unsigned short val;

	end_time = jiffies + timeout;
	do {
		
		/* use preliminary reads to settle the communication */
		snd_ac97_read(ac97, AC97_RESET);
		snd_ac97_read(ac97, AC97_VENDOR_ID1);
		snd_ac97_read(ac97, AC97_VENDOR_ID2);
		/* modem? */
		if (with_modem) {
			val = snd_ac97_read(ac97, AC97_EXTENDED_MID);
			if (val != 0xffff && (val & 1) != 0)
				return 0;
		}
		if (ac97->scaps & AC97_SCAP_DETECT_BY_VENDOR) {
			/* probably only Xbox issue - all registers are read as zero */
			val = snd_ac97_read(ac97, AC97_VENDOR_ID1);
			if (val != 0 && val != 0xffff)
				return 0;
		} else {
			/* because the PCM or MASTER volume registers can be modified,
			 * the REC_GAIN register is used for tests
			 */
			/* test if we can write to the record gain volume register */
			snd_ac97_write_cache(ac97, AC97_REC_GAIN, 0x8a05);
			if ((snd_ac97_read(ac97, AC97_REC_GAIN) & 0x7fff) == 0x0a05)
				return 0;
		}
		schedule_timeout_uninterruptible(1);
	} while (time_after_eq(end_time, jiffies));
	return -ENODEV;
}

/**
 * snd_ac97_bus - create an AC97 bus component
 * @card: the card instance
 * @num: the bus number
 * @ops: the bus callbacks table
 * @private_data: private data pointer for the new instance
 * @rbus: the pointer to store the new AC97 bus instance.
 *
 * Creates an AC97 bus component.  An struct snd_ac97_bus instance is newly
 * allocated and initialized.
 *
 * The ops table must include valid callbacks (at least read and
 * write).  The other callbacks, wait and reset, are not mandatory.
 * 
 * The clock is set to 48000.  If another clock is needed, set
 * (*rbus)->clock manually.
 *
 * The AC97 bus instance is registered as a low-level device, so you don't
 * have to release it manually.
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_ac97_bus(struct snd_card *card, int num, struct snd_ac97_bus_ops *ops,
		 void *private_data, struct snd_ac97_bus **rbus)
{
	int err;
	struct snd_ac97_bus *bus;
	static struct snd_device_ops dev_ops = {
		.dev_free =	snd_ac97_bus_dev_free,
	};

	snd_assert(card != NULL, return -EINVAL);
	snd_assert(rbus != NULL, return -EINVAL);
	bus = kzalloc(sizeof(*bus), GFP_KERNEL);
	if (bus == NULL)
		return -ENOMEM;
	bus->card = card;
	bus->num = num;
	bus->ops = ops;
	bus->private_data = private_data;
	bus->clock = 48000;
	spin_lock_init(&bus->bus_lock);
	snd_ac97_bus_proc_init(bus);
	if ((err = snd_device_new(card, SNDRV_DEV_BUS, bus, &dev_ops)) < 0) {
		snd_ac97_bus_free(bus);
		return err;
	}
	*rbus = bus;
	return 0;
}

/* stop no dev release warning */
static void ac97_device_release(struct device * dev)
{
}

/* register ac97 codec to bus */
static int snd_ac97_dev_register(struct snd_device *device)
{
	struct snd_ac97 *ac97 = device->device_data;
	int err;

	ac97->dev.bus = &ac97_bus_type;
	ac97->dev.parent = ac97->bus->card->dev;
	ac97->dev.release = ac97_device_release;
	snprintf(ac97->dev.bus_id, BUS_ID_SIZE, "%d-%d:%s",
		 ac97->bus->card->number, ac97->num,
		 snd_ac97_get_short_name(ac97));
	if ((err = device_register(&ac97->dev)) < 0) {
		snd_printk(KERN_ERR "Can't register ac97 bus\n");
		ac97->dev.bus = NULL;
		return err;
	}
	return 0;
}

/* unregister ac97 codec */
static int snd_ac97_dev_unregister(struct snd_device *device)
{
	struct snd_ac97 *ac97 = device->device_data;
	if (ac97->dev.bus)
		device_unregister(&ac97->dev);
	return snd_ac97_free(ac97);
}

/* build_ops to do nothing */
static struct snd_ac97_build_ops null_build_ops;

/**
 * snd_ac97_mixer - create an Codec97 component
 * @bus: the AC97 bus which codec is attached to
 * @template: the template of ac97, including index, callbacks and
 *         the private data.
 * @rac97: the pointer to store the new ac97 instance.
 *
 * Creates an Codec97 component.  An struct snd_ac97 instance is newly
 * allocated and initialized from the template.  The codec
 * is then initialized by the standard procedure.
 *
 * The template must include the codec number (num) and address (addr),
 * and the private data (private_data).
 * 
 * The ac97 instance is registered as a low-level device, so you don't
 * have to release it manually.
 *
 * Returns zero if successful, or a negative error code on failure.
 */
int snd_ac97_mixer(struct snd_ac97_bus *bus, struct snd_ac97_template *template, struct snd_ac97 **rac97)
{
	int err;
	struct snd_ac97 *ac97;
	struct snd_card *card;
	char name[64];
	unsigned long end_time;
	unsigned int reg;
	const struct ac97_codec_id *pid;
	static struct snd_device_ops ops = {
		.dev_free =	snd_ac97_dev_free,
		.dev_register =	snd_ac97_dev_register,
		.dev_unregister =	snd_ac97_dev_unregister,
	};

	snd_assert(rac97 != NULL, return -EINVAL);
	*rac97 = NULL;
	snd_assert(bus != NULL && template != NULL, return -EINVAL);
	snd_assert(template->num < 4 && bus->codec[template->num] == NULL, return -EINVAL);

	card = bus->card;
	ac97 = kzalloc(sizeof(*ac97), GFP_KERNEL);
	if (ac97 == NULL)
		return -ENOMEM;
	ac97->private_data = template->private_data;
	ac97->private_free = template->private_free;
	ac97->bus = bus;
	ac97->pci = template->pci;
	ac97->num = template->num;
	ac97->addr = template->addr;
	ac97->scaps = template->scaps;
	ac97->limited_regs = template->limited_regs;
	memcpy(ac97->reg_accessed, template->reg_accessed, sizeof(ac97->reg_accessed));
	bus->codec[ac97->num] = ac97;
	init_MUTEX(&ac97->reg_mutex);
	init_MUTEX(&ac97->page_mutex);

#ifdef CONFIG_PCI
	if (ac97->pci) {
		pci_read_config_word(ac97->pci, PCI_SUBSYSTEM_VENDOR_ID, &ac97->subsystem_vendor);
		pci_read_config_word(ac97->pci, PCI_SUBSYSTEM_ID, &ac97->subsystem_device);
	}
#endif
	if (bus->ops->reset) {
		bus->ops->reset(ac97);
		goto __access_ok;
	}

	ac97->id = snd_ac97_read(ac97, AC97_VENDOR_ID1) << 16;
	ac97->id |= snd_ac97_read(ac97, AC97_VENDOR_ID2);
	if (ac97->id && ac97->id != (unsigned int)-1) {
		pid = look_for_codec_id(snd_ac97_codec_ids, ac97->id);
		if (pid && (pid->flags & AC97_DEFAULT_POWER_OFF))
			goto __access_ok;
	}

	/* reset to defaults */
	if (!(ac97->scaps & AC97_SCAP_SKIP_AUDIO))
		snd_ac97_write(ac97, AC97_RESET, 0);
	if (!(ac97->scaps & AC97_SCAP_SKIP_MODEM))
		snd_ac97_write(ac97, AC97_EXTENDED_MID, 0);
	if (bus->ops->wait)
		bus->ops->wait(ac97);
	else {
		udelay(50);
		if (ac97->scaps & AC97_SCAP_SKIP_AUDIO)
			err = ac97_reset_wait(ac97, HZ/2, 1);
		else {
			err = ac97_reset_wait(ac97, HZ/2, 0);
			if (err < 0)
				err = ac97_reset_wait(ac97, HZ/2, 1);
		}
		if (err < 0) {
			snd_printk(KERN_WARNING "AC'97 %d does not respond - RESET\n", ac97->num);
			/* proceed anyway - it's often non-critical */
		}
	}
      __access_ok:
	ac97->id = snd_ac97_read(ac97, AC97_VENDOR_ID1) << 16;
	ac97->id |= snd_ac97_read(ac97, AC97_VENDOR_ID2);
	if (! (ac97->scaps & AC97_SCAP_DETECT_BY_VENDOR) &&
	    (ac97->id == 0x00000000 || ac97->id == 0xffffffff)) {
		snd_printk(KERN_ERR "AC'97 %d access is not valid [0x%x], removing mixer.\n", ac97->num, ac97->id);
		snd_ac97_free(ac97);
		return -EIO;
	}
	pid = look_for_codec_id(snd_ac97_codec_ids, ac97->id);
	if (pid)
		ac97->flags |= pid->flags;
	
	/* test for AC'97 */
	if (!(ac97->scaps & AC97_SCAP_SKIP_AUDIO) && !(ac97->scaps & AC97_SCAP_AUDIO)) {
		/* test if we can write to the record gain volume register */
		snd_ac97_write_cache(ac97, AC97_REC_GAIN, 0x8a06);
		if (((err = snd_ac97_read(ac97, AC97_REC_GAIN)) & 0x7fff) == 0x0a06)
			ac97->scaps |= AC97_SCAP_AUDIO;
	}
	if (ac97->scaps & AC97_SCAP_AUDIO) {
		ac97->caps = snd_ac97_read(ac97, AC97_RESET);
		ac97->ext_id = snd_ac97_read(ac97, AC97_EXTENDED_ID);
		if (ac97->ext_id == 0xffff)	/* invalid combination */
			ac97->ext_id = 0;
	}

	/* test for MC'97 */
	if (!(ac97->scaps & A