[ALSA] Support all sample rate conversion capabilities of DXS channels

Documentation,VIA82xx driver
Add support for full sample rate conversion capabilities of DXS
channels present in VIA VT8233/5/7 controllers:

- any sample rate in the 8000 ... 48000 Hz range is supported even if
  the AC'97 codec supports only 48000 Hz output;

- different DXS channels can use different sample rates at the same
  time (the controller performs required sample rate conversion and
  mixing in hardware).

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

Documentation/sound/alsa/ALSA-Configuration.txt

@@ -1211,16 +1211,18 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
   ------------------
 
     Module for AC'97 motherboards based on VIA 82C686A/686B, 8233,
-    8233A, 8233C, 8235 (south) bridge.
+    8233A, 8233C, 8235, 8237 (south) bridge.
 
     mpu_port	- 0x300,0x310,0x320,0x330, otherwise obtain BIOS setup
 		  [VIA686A/686B only]
     joystick	- Enable joystick (default off) [VIA686A/686B only]
     ac97_clock	- AC'97 codec clock base (default 48000Hz)
     dxs_support	- support DXS channels,
-		  0 = auto (defalut), 1 = enable, 2 = disable,
-		  3 = 48k only, 4 = no VRA
-		  [VIA8233/C,8235 only]
+		  0 = auto (default), 1 = enable, 2 = disable,
+		  3 = 48k only, 4 = no VRA, 5 = enable any sample
+		  rate and different sample rates on different
+		  channels
+		  [VIA8233/C, 8235, 8237 only]
     ac97_quirk  - AC'97 workaround for strange hardware
                   See the description of intel8x0 module for details.
 
@@ -1232,18 +1234,21 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
           default value 1.4.  Then the interrupt number will be
           assigned under 15. You might also upgrade your BIOS.
     
-    Note: VIA8233/5 (not VIA8233A) can support DXS (direct sound)
+    Note: VIA8233/5/7 (not VIA8233A) can support DXS (direct sound)
 	  channels as the first PCM.  On these channels, up to 4
-	  streams can be played at the same time.
+	  streams can be played at the same time, and the controller
+	  can perform sample rate conversion with separate rates for
+	  each channel.
 	  As default (dxs_support = 0), 48k fixed rate is chosen
 	  except for the known devices since the output is often
 	  noisy except for 48k on some mother boards due to the
 	  bug of BIOS.
-	  Please try once dxs_support=1 and if it works on other
+	  Please try once dxs_support=5 and if it works on other
 	  sample rates (e.g. 44.1kHz of mp3 playback), please let us
 	  know the PCI subsystem vendor/device id's (output of
 	  "lspci -nv").
-	  If it doesn't work, try dxs_support=4.  If it still doesn't
+	  If dxs_support=5 does not work, try dxs_support=1; if it
+	  doesn't work too, try dxs_support=4.  If it still doesn't
 	  work and the default setting is ok, dxs_support=3 is the
 	  right choice.  If the default setting doesn't work at all,
 	  try dxs_support=2 to disable the DXS channels.

sound/pci/via82xx.c

@@ -101,7 +101,7 @@ MODULE_PARM_DESC(ac97_clock, "AC'97 codec clock (default 48000Hz).");
 module_param_array(ac97_quirk, charp, NULL, 0444);
 MODULE_PARM_DESC(ac97_quirk, "AC'97 workaround for strange hardware.");
 module_param_array(dxs_support, int, NULL, 0444);
-MODULE_PARM_DESC(dxs_support, "Support for DXS channels (0 = auto, 1 = enable, 2 = disable, 3 = 48k only, 4 = no VRA)");
+MODULE_PARM_DESC(dxs_support, "Support for DXS channels (0 = auto, 1 = enable, 2 = disable, 3 = 48k only, 4 = no VRA, 5 = enable any sample rate)");
 
 
 /* pci ids */
@@ -302,6 +302,7 @@ DEFINE_VIA_REGSET(CAPTURE_8233, 0x60);
 #define VIA_DXS_DISABLE	2
 #define VIA_DXS_48K	3
 #define VIA_DXS_NO_VRA	4
+#define VIA_DXS_SRC	5
 
 
 /*
@@ -380,6 +381,7 @@ struct _snd_via82xx {
 	struct via_rate_lock rates[2]; /* playback and capture */
 	unsigned int dxs_fixed: 1;	/* DXS channel accepts only 48kHz */
 	unsigned int no_vra: 1;		/* no need to set VRA on DXS channels */
+	unsigned int dxs_src: 1;	/* use full SRC capabilities of DXS */
 	unsigned int spdif_on: 1;	/* only spdif rates work to external DACs */
 
 	snd_pcm_t *pcms[2];
@@ -924,15 +926,16 @@ static int snd_via8233_playback_prepare(snd_pcm_substream_t *substream)
 	via82xx_t *chip = snd_pcm_substream_chip(substream);
 	viadev_t *viadev = (viadev_t *)substream->runtime->private_data;
 	snd_pcm_runtime_t *runtime = substream->runtime;
+	int ac97_rate = chip->dxs_src ? 48000 : runtime->rate;
 	int rate_changed;
 	u32 rbits;
 
-	if ((rate_changed = via_lock_rate(&chip->rates[0], runtime->rate)) < 0)
+	if ((rate_changed = via_lock_rate(&chip->rates[0], ac97_rate)) < 0)
 		return rate_changed;
 	if (rate_changed) {
 		snd_ac97_set_rate(chip->ac97, AC97_PCM_FRONT_DAC_RATE,
 				  chip->no_vra ? 48000 : runtime->rate);
-		snd_ac97_set_rate(chip->ac97, AC97_SPDIF, runtime->rate);
+		snd_ac97_set_rate(chip->ac97, AC97_SPDIF, ac97_rate);
 	}
 	if (runtime->rate == 48000)
 		rbits = 0xfffff;
@@ -1074,6 +1077,12 @@ static int snd_via82xx_pcm_open(via82xx_t *chip, viadev_t *viadev, snd_pcm_subst
 		/* fixed DXS playback rate */
 		runtime->hw.rates = SNDRV_PCM_RATE_48000;
 		runtime->hw.rate_min = runtime->hw.rate_max = 48000;
+	} else if (chip->dxs_src && viadev->reg_offset < 0x40) {
+		/* use full SRC capabilities of DXS */
+		runtime->hw.rates = (SNDRV_PCM_RATE_CONTINUOUS |
+				     SNDRV_PCM_RATE_8000_48000);
+		runtime->hw.rate_min = 8000;
+		runtime->hw.rate_max = 48000;
 	} else if (! ratep->rate) {
 		int idx = viadev->direction ? AC97_RATES_ADC : AC97_RATES_FRONT_DAC;
 		runtime->hw.rates = chip->ac97->rates[idx];
@@ -2149,6 +2158,7 @@ static int __devinit check_dxs_list(struct pci_dev *pci)
 		{ .vendor = 0x1043, .device = 0x8095, .action = VIA_DXS_NO_VRA }, /* ASUS A7V8X (FIXME: possibly VIA_DXS_ENABLE?)*/
 		{ .vendor = 0x1043, .device = 0x80a1, .action = VIA_DXS_NO_VRA }, /* ASUS A7V8-X */
 		{ .vendor = 0x1043, .device = 0x80b0, .action = VIA_DXS_NO_VRA }, /* ASUS A7V600 & K8V*/ 
+		{ .vendor = 0x1043, .device = 0x812a, .action = VIA_DXS_SRC    }, /* ASUS A8V Deluxe */ 
 		{ .vendor = 0x1071, .device = 0x8375, .action = VIA_DXS_NO_VRA }, /* Vobis/Yakumo/Mitac notebook */
 		{ .vendor = 0x10cf, .device = 0x118e, .action = VIA_DXS_ENABLE }, /* FSC laptop */
 		{ .vendor = 0x1106, .device = 0x4161, .action = VIA_DXS_NO_VRA }, /* ASRock K7VT2 */
@@ -2288,6 +2298,10 @@ static int __devinit snd_via82xx_probe(struct pci_dev *pci,
 				chip->dxs_fixed = 1;
 			else if (dxs_support[dev] == VIA_DXS_NO_VRA)
 				chip->no_vra = 1;
+			else if (dxs_support[dev] == VIA_DXS_SRC) {
+				chip->no_vra = 1;
+				chip->dxs_src = 1;
+			}
 		}
 		if ((err = snd_via8233_init_misc(chip, dev)) < 0)
 			goto __error;