[ALSA] Improve SPDIF playback via the P16V/CA0151 chip.

EMU10K1/EMU10K2 driver
Although we can set 44100 as the output rate, the SPDIF can do it, but the Analog output cannot.
The SPDIF has the bug, whereby the Left channel arrives one sample late, so although we don't do any resampling,
it is not good for AC3 non-audio output.

Signed-off-by: James Courtier-Dutton <James@superbug.co.uk>

include/sound/emu10k1.h

@@ -747,6 +747,7 @@
 						/* Assumes sample lock				*/
 
 /* These three bitfields apply to CDSRCS, GPSRCS, and (except as noted) ZVSRCS.			*/
+#define SRCS_SPDIFVALID		0x04000000	/* SPDIF stream valid				*/
 #define SRCS_SPDIFLOCKED	0x02000000	/* SPDIF stream locked				*/
 #define SRCS_RATELOCKED		0x01000000	/* Sample rate locked				*/
 #define SRCS_ESTSAMPLERATE	0x0007ffff	/* Do not modify this field.			*/

sound/pci/emu10k1/emumixer.c

@@ -935,10 +935,12 @@ int __devinit snd_emu10k1_mixer(emu10k1_t *emu)
 			return -ENOMEM;
 		if ((err = snd_ctl_add(card, kctl)))
 			return err;
+#if 0
 		if ((kctl = snd_ctl_new1(&snd_audigy_spdif_output_rate, emu)) == NULL)
 			return -ENOMEM;
 		if ((err = snd_ctl_add(card, kctl)))
 			return err;
+#endif
 	} else if (! emu->card_capabilities->ecard) {
 		/* sb live! */
 		if ((kctl = snd_ctl_new1(&snd_emu10k1_shared_spdif, emu)) == NULL)

sound/pci/emu10k1/emuproc.c

@@ -30,6 +30,7 @@
 #include <linux/init.h>
 #include <sound/core.h>
 #include <sound/emu10k1.h>
+#include "p16v.h"
 
 static void snd_emu10k1_proc_spdif_status(emu10k1_t * emu,
 					  snd_info_buffer_t * buffer,
@@ -62,6 +63,7 @@ static void snd_emu10k1_proc_spdif_status(emu10k1_t * emu,
 
 		if (rate_reg > 0) {
 			rate = snd_emu10k1_ptr_read(emu, rate_reg, 0);
+			snd_iprintf(buffer, "S/PDIF Valid          : %s\n", rate & SRCS_SPDIFVALID ? "on" : "off");
 			snd_iprintf(buffer, "S/PDIF Locked         : %s\n", rate & SRCS_SPDIFLOCKED ? "on" : "off");
 			snd_iprintf(buffer, "Rate Locked           : %s\n", rate & SRCS_RATELOCKED ? "on" : "off");
 			/* From ((Rate * 48000 ) / 262144); */
@@ -244,6 +246,21 @@ static void snd_emu10k1_proc_spdif_read(snd_info_entry_t *entry,
 #endif
 }
 
+static void snd_emu10k1_proc_rates_read(snd_info_entry_t *entry, 
+				  snd_info_buffer_t * buffer)
+{
+	static int samplerate[8] = { 44100, 48000, 96000, 192000, 4, 5, 6, 7 };
+	emu10k1_t *emu = entry->private_data;
+	unsigned int val, tmp, n;
+	val = snd_emu10k1_ptr20_read(emu, CAPTURE_RATE_STATUS, 0);
+	tmp = (val >> 16) & 0x8;
+	for (n=0;n<4;n++) {
+		tmp = val >> (16 + (n*4));
+		if (tmp & 0x8) snd_iprintf(buffer, "Channel %d: Rate=%d\n", n, samplerate[tmp & 0x7]);
+		else snd_iprintf(buffer, "Channel %d: No input\n", n);
+	}
+}
+
 static void snd_emu10k1_proc_acode_read(snd_info_entry_t *entry, 
 				        snd_info_buffer_t * buffer)
 {
@@ -540,6 +557,10 @@ int __devinit snd_emu10k1_proc_init(emu10k1_t * emu)
 		if (! snd_card_proc_new(emu->card, "spdif-in", &entry))
 			snd_info_set_text_ops(entry, emu, 2048, snd_emu10k1_proc_spdif_read);
 	}
+	if (emu->card_capabilities->ca0151_chip) {
+		if (! snd_card_proc_new(emu->card, "capture-rates", &entry))
+			snd_info_set_text_ops(entry, emu, 2048, snd_emu10k1_proc_rates_read);
+	}
 
 	if (! snd_card_proc_new(emu->card, "voices", &entry))
 		snd_info_set_text_ops(entry, emu, 2048, snd_emu10k1_proc_voices_read);

sound/pci/emu10k1/p16v.c

@@ -119,8 +119,8 @@ static snd_pcm_hardware_t snd_p16v_playback_hw = {
 				 SNDRV_PCM_INFO_BLOCK_TRANSFER |
 				 SNDRV_PCM_INFO_MMAP_VALID),
 	.formats =		SNDRV_PCM_FMTBIT_S32_LE, /* Only supports 24-bit samples padded to 32 bits. */
-	.rates =		SNDRV_PCM_RATE_192000 | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_48000 ,
-	.rate_min =		48000,
+	.rates =		SNDRV_PCM_RATE_192000 | SNDRV_PCM_RATE_96000 | SNDRV_PCM_RATE_48000 | SNDRV_PCM_RATE_44100, 
+	.rate_min =		44100,
 	.rate_max =		192000,
 	.channels_min =		8, 
 	.channels_max =		8,
@@ -324,19 +324,17 @@ static int snd_p16v_pcm_prepare_playback(snd_pcm_substream_t *substream)
 	tmp = snd_emu10k1_ptr_read(emu, A_SPDIF_SAMPLERATE, channel);
         switch (runtime->rate) {
 	case 44100:
-	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe000) | 0x8000); /* FIXME: This will change the capture rate as well! */
-	  break;
-	case 48000:
-	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe000) | 0x0000); /* FIXME: This will change the capture rate as well! */
+	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe0e0) | 0x8080);
 	  break;
 	case 96000:
-	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe000) | 0x4000); /* FIXME: This will change the capture rate as well! */
+	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe0e0) | 0x4040);
 	  break;
 	case 192000:
-	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe000) | 0x2000); /* FIXME: This will change the capture rate as well! */
+	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe0e0) | 0x2020);
 	  break;
+	case 48000:
 	default:
-	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, 0x0000); /* FIXME: This will change the capture rate as well! */
+	  snd_emu10k1_ptr_write(emu, A_SPDIF_SAMPLERATE, channel, (tmp & ~0xe0e0) | 0x0000);
 	  break;
 	}
 	/* FIXME: Check emu->buffer.size before actually writing to it. */