Perform warm or cold reset AC97 per the spec depending on state of the

codec during initialization.  This code mirrors the reset code used on
the VIA82c686 and fixes a codec initialization failure (SoundMAX
AD1885) reported by Matthias Schuendehuette.

2 files changed, 49 insertions, 22 deletions

diff --git a/sys/dev/sound/pci/via8233.c b/sys/dev/sound/pci/via8233.c
index 883012c..f8f136e 100644
--- a/sys/dev/sound/pci/via8233.c
+++ b/sys/dev/sound/pci/via8233.c
@@ -653,33 +653,56 @@ dma_cb(void *p, bus_dma_segment_t *bds, int a, int b)
 static int
 via_chip_init(device_t dev)
 {
-	int i, s;
-
-	pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 0, 1);	
-	DELAY(100);
-
-	/* assert ACLink reset */
-	pci_write_config(dev, VIA_PCI_ACLINK_CTRL, VIA_PCI_ACLINK_NRST, 1);
-	DELAY(2);
-
-	/* deassert ACLink reset, force SYNC (warm AC'97 reset) */
-	pci_write_config(dev, VIA_PCI_ACLINK_CTRL,
-			 VIA_PCI_ACLINK_NRST | VIA_PCI_ACLINK_SYNC, 1);
+	u_int32_t data, cnt;
+
+	/* Wake up and reset AC97 if necessary */
+	data = pci_read_config(dev, VIA_PCI_ACLINK_STAT, 1);
+
+	if ((data & VIA_PCI_ACLINK_C00_READY) == 0) {
+		/* Cold reset per ac97r2.3 spec (page 95) */
+		/* Assert low */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN, 1); 
+		/* Wait T_rst_low */
+		DELAY(100);				
+		/* Assert high */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN | VIA_PCI_ACLINK_NRST, 1);
+		/* Wait T_rst2clk */
+		DELAY(5);
+		/* Assert low */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN, 1);
+	} else {
+		/* Warm reset */
+		/* Force no sync */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN, 1);
+		DELAY(100);
+		/* Sync */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN | VIA_PCI_ACLINK_SYNC, 1);
+		/* Wait T_sync_high */
+		DELAY(5);
+		/* Force no sync */
+		pci_write_config(dev, VIA_PCI_ACLINK_CTRL, 
+				 VIA_PCI_ACLINK_EN, 1);
+		/* Wait T_sync2clk */
+		DELAY(5);
+	}
 
-	/* ACLink on, deassert ACLink reset, VSR, SGD data out */
-	pci_write_config(dev, VIA_PCI_ACLINK_CTRL,
-			 VIA_PCI_ACLINK_EN | VIA_PCI_ACLINK_NRST
-			 | VIA_PCI_ACLINK_VRATE | VIA_PCI_ACLINK_SGD, 1);
+	/* Power everything up */
+	pci_write_config(dev, VIA_PCI_ACLINK_CTRL, VIA_PCI_ACLINK_DESIRED, 1);
 
-	for (i = 0; i < 100; i++) {
-		s = pci_read_config(dev, VIA_PCI_ACLINK_STAT, 1);
-		if (s & VIA_PCI_ACLINK_C00_READY) {
-			s = pci_read_config(dev, VIA_PCI_ACLINK_CTRL, 1);
+	/* Wait for codec to become ready (largest reported delay 310ms) */
+	for (cnt = 0; cnt < 2000; cnt++) {
+		data = pci_read_config(dev, VIA_PCI_ACLINK_STAT, 1);
+		if (data & VIA_PCI_ACLINK_C00_READY) {
 			return 0;
 		}
-		DELAY(10);
+		DELAY(5000);
 	}
-	device_printf(dev, "primary codec not ready (s = 0x%02x)\n", s);
+	device_printf(dev, "primary codec not ready (cnt = 0x%02x)\n", cnt);
 	return ENXIO;
 }
 
diff --git a/sys/dev/sound/pci/via8233.h b/sys/dev/sound/pci/via8233.h
index f0caca5..bc6f57a 100644
--- a/sys/dev/sound/pci/via8233.h
+++ b/sys/dev/sound/pci/via8233.h
@@ -72,6 +72,10 @@
 #	define VIA_PCI_ACLINK_SERIAL	0x10
 #	define VIA_PCI_ACLINK_VRATE	0x08
 #	define VIA_PCI_ACLINK_SGD	0x04
+#	define VIA_PCI_ACLINK_DESIRED 	(VIA_PCI_ACLINK_EN | 		      \
+					 VIA_PCI_ACLINK_NRST |		      \
+					 VIA_PCI_ACLINK_VRATE | 	      \
+					 VIA_PCI_ACLINK_SGD)
 
 #define VIA_MC_SGD_STATUS	0x40
 #define VIA_WR0_SGD_STATUS	0x60