ALSA: wss_lib: rework snd_ad1848_probe()

Make snd_ad1848_probe() easier to follow. With an exception for only
trying once as soon as the codec is out of init (which should be all
that's needed) the detection logic should be unchanged.
Signed-off-by: Rene Herman <rene.herman@gmail.com>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/isa/wss/wss_lib.c

@@ -1147,79 +1147,84 @@ static snd_pcm_uframes_t snd_wss_capture_pointer(struct snd_pcm_substream *subst
 
 static int snd_ad1848_probe(struct snd_wss *chip)
 {
+	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
 	unsigned long flags;
-	int i, id, rev, ad1847;
+	unsigned char r;
+	unsigned short hardware = 0;
+	int err = 0;
+	int i;
 
-	id = 0;
-	ad1847 = 0;
-	for (i = 0; i < 1000; i++) {
-		mb();
-		if (inb(chip->port + CS4231P(REGSEL)) & CS4231_INIT)
-			msleep(1);
-		else {
-			spin_lock_irqsave(&chip->reg_lock, flags);
-			snd_wss_out(chip, CS4231_MISC_INFO, 0x00);
-			snd_wss_out(chip, CS4231_LEFT_INPUT, 0xaa);
-			snd_wss_out(chip, CS4231_RIGHT_INPUT, 0x45);
-			rev = snd_wss_in(chip, CS4231_RIGHT_INPUT);
-			if (rev == 0x65) {
-				spin_unlock_irqrestore(&chip->reg_lock, flags);
-				id = 1;
-				ad1847 = 1;
-				break;
-			}
-			if (rev == 0x45) {
-				rev = snd_wss_in(chip, CS4231_LEFT_INPUT);
-				if (rev == 0xaa || rev == 0x8a) {
-					spin_unlock_irqrestore(&chip->reg_lock, flags);
-					id = 1;
-					break;
-				}
-			}
-			spin_unlock_irqrestore(&chip->reg_lock, flags);
-		}
+	while (wss_inb(chip, CS4231P(REGSEL)) & CS4231_INIT) {
+		if (time_after(jiffies, timeout))
+			return -ENODEV;
+		cond_resched();
 	}
-	if (id != 1)
-		return -ENODEV;	/* no valid device found */
-	id = 0;
-	if (chip->hardware == WSS_HW_DETECT)
-		id = ad1847 ? WSS_HW_AD1847 : WSS_HW_AD1848;
-
 	spin_lock_irqsave(&chip->reg_lock, flags);
-	inb(chip->port + CS4231P(STATUS));	/* clear any pendings IRQ */
-	outb(0, chip->port + CS4231P(STATUS));
-	mb();
-	if (id == WSS_HW_AD1848) {
-		/* check if there are more than 16 registers */
-		rev = snd_wss_in(chip, CS4231_MISC_INFO);
-		snd_wss_out(chip, CS4231_MISC_INFO, 0x40);
-		for (i = 0; i < 16; ++i) {
-			if (snd_wss_in(chip, i) != snd_wss_in(chip, i + 16)) {
-				id = WSS_HW_CMI8330;
-				break;
-			}
+
+	/* set CS423x MODE 1 */
+	snd_wss_out(chip, CS4231_MISC_INFO, 0);
+
+	snd_wss_out(chip, CS4231_RIGHT_INPUT, 0x45); /* 0x55 & ~0x10 */
+	r = snd_wss_in(chip, CS4231_RIGHT_INPUT);
+	if (r != 0x45) {
+		/* RMGE always high on AD1847 */
+		if ((r & ~CS4231_ENABLE_MIC_GAIN) != 0x45) {
+			err = -ENODEV;
+			goto out;
+		}
+		hardware = WSS_HW_AD1847;
+	} else {
+		snd_wss_out(chip, CS4231_LEFT_INPUT,  0xaa);
+		r = snd_wss_in(chip, CS4231_LEFT_INPUT);
+		/* L/RMGE always low on AT2320 */
+		if ((r | CS4231_ENABLE_MIC_GAIN) != 0xaa) {
+			err = -ENODEV;
+			goto out;
 		}
-		snd_wss_out(chip, CS4231_MISC_INFO, 0x00);
-		if (id != WSS_HW_CMI8330 && (rev & 0x80))
-			id = WSS_HW_CS4248;
-		if (id == WSS_HW_CMI8330 && (rev & 0x0f) != 0x0a)
-			id = 0;
 	}
-	if (id == WSS_HW_CMI8330) {
-		/* verify it is not CS4231 by changing the version register */
-		/* on CMI8330 it is volume control register and can be set 0 */
-		snd_wss_out(chip, CS4231_MISC_INFO, CS4231_MODE2);
-		snd_wss_dout(chip, CS4231_VERSION, 0x00);
-		rev = snd_wss_in(chip, CS4231_VERSION) & 0xe7;
-		if (rev)
-			id = 0;
-		snd_wss_out(chip, CS4231_MISC_INFO, 0);
+
+	/* clear pending IRQ */
+	wss_inb(chip, CS4231P(STATUS));
+	wss_outb(chip, CS4231P(STATUS), 0);
+	mb();
+
+	if ((chip->hardware & WSS_HW_TYPE_MASK) != WSS_HW_DETECT)
+		goto out;
+
+	if (hardware) {
+		chip->hardware = hardware;
+		goto out;
 	}
-	if (id)
-		chip->hardware = id;
 
+	r = snd_wss_in(chip, CS4231_MISC_INFO);
+
+	/* set CS423x MODE 2 */
+	snd_wss_out(chip, CS4231_MISC_INFO, CS4231_MODE2);
+	for (i = 0; i < 16; i++) {
+		if (snd_wss_in(chip, i) != snd_wss_in(chip, 16 + i)) {
+			/* we have more than 16 registers: check ID */
+			if ((r & 0xf) != 0xa)
+				goto out_mode;
+			/*
+			 * on CMI8330, CS4231_VERSION is volume control and
+			 * can be set to 0
+			 */
+			snd_wss_dout(chip, CS4231_VERSION, 0);
+			r = snd_wss_in(chip, CS4231_VERSION) & 0xe7;
+			if (!r)
+				chip->hardware = WSS_HW_CMI8330;
+			goto out_mode;
+		}
+	}
+	if (r & 0x80)
+		chip->hardware = WSS_HW_CS4248;
+	else
+		chip->hardware = WSS_HW_AD1848;
+out_mode:
+	snd_wss_out(chip, CS4231_MISC_INFO, 0);
+out:
 	spin_unlock_irqrestore(&chip->reg_lock, flags);
-	return 0;		/* all things are ok.. */
+	return err;
 }
 
 static int snd_wss_probe(struct snd_wss *chip)