[ALSA] Current driver does not utilize 44.1kHz high quality sampling rate converter.

Following patch will make the driver to use the 44.1kHz SRC automatically
if the pcm source is 44.1kHz signed 16bit stereo.
The SRC is available in YMF754 only.
Signed-off-by: Teru KAMOGASHIRA <teru@sodan.ecc.u-tokyo.ac.jp>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

include/sound/ymfpci.h

@@ -270,6 +270,7 @@ struct snd_ymfpci_pcm {
 	struct snd_pcm_substream *substream;
 	struct snd_ymfpci_voice *voices[2];	/* playback only */
 	unsigned int running: 1,
+		     use_441_slot: 1,
 	             output_front: 1,
 	             output_rear: 1,
 	             swap_rear: 1;
@@ -324,6 +325,7 @@ struct snd_ymfpci {
 
 	u32 active_bank;
 	struct snd_ymfpci_voice voices[64];
+	int src441_used;
 
 	struct snd_ac97_bus *ac97_bus;
 	struct snd_ac97 *ac97;
@@ -346,7 +348,7 @@ struct snd_ymfpci {
 	int mode_dup4ch;
 	int rear_opened;
 	int spdif_opened;
-	struct {
+	struct snd_ymfpci_pcm_mixer {
 		u16 left;
 		u16 right;
 		struct snd_kcontrol *ctl;

sound/pci/ymfpci/ymfpci_main.c

@@ -171,6 +171,17 @@ static u32 snd_ymfpci_calc_lpfQ(u32 rate)
 	return val[0];
 }
 
+static void snd_ymfpci_pcm_441_volume_set(struct snd_ymfpci_pcm *ypcm)
+{
+	unsigned int value;
+	struct snd_ymfpci_pcm_mixer *mixer;
+	
+	mixer = &ypcm->chip->pcm_mixer[ypcm->substream->number];
+	value = min_t(unsigned int, mixer->left, 0x7fff) >> 1;
+	value |= (min_t(unsigned int, mixer->right, 0x7fff) >> 1) << 16;
+	snd_ymfpci_writel(ypcm->chip, YDSXGR_BUF441OUTVOL, value);
+}
+
 /*
  *  Hardware start management
  */
@@ -282,6 +293,10 @@ static int snd_ymfpci_voice_free(struct snd_ymfpci *chip, struct snd_ymfpci_voic
 	snd_assert(pvoice != NULL, return -EINVAL);
 	snd_ymfpci_hw_stop(chip);
 	spin_lock_irqsave(&chip->voice_lock, flags);
+	if (pvoice->number == chip->src441_used) {
+		chip->src441_used = -1;
+		pvoice->ypcm->use_441_slot = 0;
+	}
 	pvoice->use = pvoice->pcm = pvoice->synth = pvoice->midi = 0;
 	pvoice->ypcm = NULL;
 	pvoice->interrupt = NULL;
@@ -386,7 +401,7 @@ static int snd_ymfpci_playback_trigger(struct snd_pcm_substream *substream,
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 	case SNDRV_PCM_TRIGGER_RESUME:
 		chip->ctrl_playback[ypcm->voices[0]->number + 1] = cpu_to_le32(ypcm->voices[0]->bank_addr);
-		if (ypcm->voices[1] != NULL)
+		if (ypcm->voices[1] != NULL && !ypcm->use_441_slot)
 			chip->ctrl_playback[ypcm->voices[1]->number + 1] = cpu_to_le32(ypcm->voices[1]->bank_addr);
 		ypcm->running = 1;
 		break;
@@ -394,7 +409,7 @@ static int snd_ymfpci_playback_trigger(struct snd_pcm_substream *substream,
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 		chip->ctrl_playback[ypcm->voices[0]->number + 1] = 0;
-		if (ypcm->voices[1] != NULL)
+		if (ypcm->voices[1] != NULL && !ypcm->use_441_slot)
 			chip->ctrl_playback[ypcm->voices[1]->number + 1] = 0;
 		ypcm->running = 0;
 		break;
@@ -481,6 +496,7 @@ static void snd_ymfpci_pcm_init_voice(struct snd_ymfpci_pcm *ypcm, unsigned int
 	unsigned int nbank;
 	u32 vol_left, vol_right;
 	u8 use_left, use_right;
+	unsigned long flags;
 
 	snd_assert(voice != NULL, return);
 	if (runtime->channels == 1) {
@@ -499,11 +515,27 @@ static void snd_ymfpci_pcm_init_voice(struct snd_ymfpci_pcm *ypcm, unsigned int
 		vol_left = cpu_to_le32(0x40000000);
 		vol_right = cpu_to_le32(0x40000000);
 	}
+	spin_lock_irqsave(&ypcm->chip->voice_lock, flags);
 	format = runtime->channels == 2 ? 0x00010000 : 0;
 	if (snd_pcm_format_width(runtime->format) == 8)
 		format |= 0x80000000;
+	else if (ypcm->chip->device_id == PCI_DEVICE_ID_YAMAHA_754 &&
+		 runtime->rate == 44100 && runtime->channels == 2 &&
+		 voiceidx == 0 && (ypcm->chip->src441_used == -1 ||
+				   ypcm->chip->src441_used == voice->number)) {
+		ypcm->chip->src441_used = voice->number;
+		ypcm->use_441_slot = 1;
+		format |= 0x10000000;
+		snd_ymfpci_pcm_441_volume_set(ypcm);
+	}
+	if (ypcm->chip->src441_used == voice->number &&
+	    (format & 0x10000000) == 0) {
+		ypcm->chip->src441_used = -1;
+		ypcm->use_441_slot = 0;
+	}
 	if (runtime->channels == 2 && (voiceidx & 1) != 0)
 		format |= 1;
+	spin_unlock_irqrestore(&ypcm->chip->voice_lock, flags);
 	for (nbank = 0; nbank < 2; nbank++) {
 		bank = &voice->bank[nbank];
 		memset(bank, 0, sizeof(*bank));
@@ -1714,7 +1746,10 @@ static int snd_ymfpci_pcm_vol_put(struct snd_kcontrol *kcontrol,
 		spin_lock_irqsave(&chip->voice_lock, flags);
 		if (substream->runtime && substream->runtime->private_data) {
 			struct snd_ymfpci_pcm *ypcm = substream->runtime->private_data;
+			if (!ypcm->use_441_slot)
 				ypcm->update_pcm_vol = 2;
+			else
+				snd_ymfpci_pcm_441_volume_set(ypcm);
 		}
 		spin_unlock_irqrestore(&chip->voice_lock, flags);
 		return 1;
@@ -2253,7 +2288,7 @@ static int saved_regs_index[] = {
 	YDSXGR_PRIADCLOOPVOL,
 	YDSXGR_NATIVEDACINVOL,
 	YDSXGR_NATIVEDACOUTVOL,
-	// YDSXGR_BUF441OUTVOL,
+	YDSXGR_BUF441OUTVOL,
 	YDSXGR_NATIVEADCINVOL,
 	YDSXGR_SPDIFLOOPVOL,
 	YDSXGR_SPDIFOUTVOL,
@@ -2368,6 +2403,7 @@ int __devinit snd_ymfpci_create(struct snd_card *card,
 	chip->reg_area_phys = pci_resource_start(pci, 0);
 	chip->reg_area_virt = ioremap_nocache(chip->reg_area_phys, 0x8000);
 	pci_set_master(pci);
+	chip->src441_used = -1;
 
 	if ((chip->res_reg_area = request_mem_region(chip->reg_area_phys, 0x8000, "YMFPCI")) == NULL) {
 		snd_printk(KERN_ERR "unable to grab memory region 0x%lx-0x%lx\n", chip->reg_area_phys, chip->reg_area_phys + 0x8000 - 1);