ALSA: firewire-motu: code refactoring to handle model specific switch for protocol v2

In MOTU FireWire series, devices which support protocol version 2 have
several types of hardware design to process audio data frames for isoc
packet. Roughly devices are categorized into three groups:
 - 828mkII
 - Traveler/896HD
 - UltraLite/8pre FireWire

Some bit flags in register addressed by 0x'ffff'f000'0b14
includes device-specific effects.

This commit cleanups implementation of protocol v2 in this point.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20191030080644.1704-6-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/motu/motu-protocol-v2.c

@@ -12,10 +12,8 @@
 #define  V2_CLOCK_RATE_SHIFT			3
 #define  V2_CLOCK_SRC_MASK			0x00000007
 #define  V2_CLOCK_SRC_SHIFT			0
-#define  V2_CLOCK_TRAVELER_FETCH_DISABLE	0x04000000
-#define  V2_CLOCK_TRAVELER_FETCH_ENABLE		0x03000000
-#define  V2_CLOCK_8PRE_FETCH_DISABLE		0x02000000
-#define  V2_CLOCK_8PRE_FETCH_ENABLE		0x00000000
+#define  V2_CLOCK_FETCH_ENABLE			0x02000000
+#define  V2_CLOCK_MODEL_SPECIFIC		0x04000000
 
 #define V2_IN_OUT_CONF_OFFSET			0x0c04
 #define  V2_OPT_OUT_IFACE_MASK			0x00000c00
@@ -73,11 +71,6 @@ static int v2_set_clock_rate(struct snd_motu *motu, unsigned int rate)
 	data &= ~V2_CLOCK_RATE_MASK;
 	data |= i << V2_CLOCK_RATE_SHIFT;
 
-	if (motu->spec == &snd_motu_spec_traveler) {
-		data &= ~V2_CLOCK_TRAVELER_FETCH_ENABLE;
-		data |= V2_CLOCK_TRAVELER_FETCH_DISABLE;
-	}
-
 	reg = cpu_to_be32(data);
 	return snd_motu_transaction_write(motu, V2_CLOCK_STATUS_OFFSET, &reg,
 					  sizeof(reg));
@@ -145,42 +138,49 @@ static int v2_get_clock_source(struct snd_motu *motu,
 
 static int v2_switch_fetching_mode(struct snd_motu *motu, bool enable)
 {
+	enum snd_motu_clock_source src;
 	__be32 reg;
 	u32 data;
 	int err = 0;
 
-	if (motu->spec == &snd_motu_spec_traveler ||
-	    motu->spec == &snd_motu_spec_8pre) {
-		err = snd_motu_transaction_read(motu, V2_CLOCK_STATUS_OFFSET,
-						&reg, sizeof(reg));
+	// 828mkII implements Altera ACEX 1K EP1K30. Nothing to do.
+	if (motu->spec == &snd_motu_spec_828mk2)
+		return 0;
+
+	err = snd_motu_transaction_read(motu, V2_CLOCK_STATUS_OFFSET, &reg,
+					sizeof(reg));
+	if (err < 0)
+		return err;
+	data = be32_to_cpu(reg);
+
+	err = get_clock_source(motu, data, &src);
+	if (err < 0)
+		return err;
+
+	data &= ~(V2_CLOCK_FETCH_ENABLE | V2_CLOCK_MODEL_SPECIFIC);
+	if (enable)
+		data |= V2_CLOCK_FETCH_ENABLE;
+
+	if (motu->spec->flags & SND_MOTU_SPEC_SUPPORT_CLOCK_X4) {
+		// Expected for Traveler and 896HD, which implements Altera
+		// Cyclone EP1C3.
+		data |= V2_CLOCK_MODEL_SPECIFIC;
+	} else {
+		// For UltraLite and 8pre, which implements Xilinx Spartan
+		// XC3S200.
+		unsigned int rate;
+
+		err = get_clock_rate(data, &rate);
 		if (err < 0)
 			return err;
-		data = be32_to_cpu(reg);
-
-		if (motu->spec == &snd_motu_spec_traveler) {
-			data &= ~(V2_CLOCK_TRAVELER_FETCH_DISABLE |
-				  V2_CLOCK_TRAVELER_FETCH_ENABLE);
-
-			if (enable)
-				data |= V2_CLOCK_TRAVELER_FETCH_ENABLE;
-			else
-				data |= V2_CLOCK_TRAVELER_FETCH_DISABLE;
-		} else if (motu->spec == &snd_motu_spec_8pre) {
-			data &= ~(V2_CLOCK_8PRE_FETCH_DISABLE |
-				  V2_CLOCK_8PRE_FETCH_ENABLE);
-
-			if (enable)
-				data |= V2_CLOCK_8PRE_FETCH_DISABLE;
-			else
-				data |= V2_CLOCK_8PRE_FETCH_ENABLE;
-		}
 
-		reg = cpu_to_be32(data);
-		err = snd_motu_transaction_write(motu, V2_CLOCK_STATUS_OFFSET,
-						 &reg, sizeof(reg));
+		if (src == SND_MOTU_CLOCK_SOURCE_SPH && rate > 48000)
+			data |= V2_CLOCK_MODEL_SPECIFIC;
 	}
 
-	return err;
+	reg = cpu_to_be32(data);
+	return snd_motu_transaction_write(motu, V2_CLOCK_STATUS_OFFSET, &reg,
+					  sizeof(reg));
 }
 
 static void calculate_fixed_part(struct snd_motu_packet_format *formats,

sound/firewire/motu/motu.c

@@ -172,7 +172,7 @@ static void motu_bus_update(struct fw_unit *unit)
 	snd_motu_transaction_reregister(motu);
 }
 
-static const struct snd_motu_spec motu_828mk2 = {
+const struct snd_motu_spec snd_motu_spec_828mk2 = {
 	.name = "828mk2",
 	.protocol = &snd_motu_protocol_v2,
 	.flags = SND_MOTU_SPEC_SUPPORT_CLOCK_X2 |
@@ -187,7 +187,7 @@ static const struct snd_motu_spec motu_828mk2 = {
 	.analog_out_ports = 8,
 };
 
-const struct snd_motu_spec snd_motu_spec_traveler = {
+static const struct snd_motu_spec motu_traveler = {
 	.name = "Traveler",
 	.protocol = &snd_motu_protocol_v2,
 	.flags = SND_MOTU_SPEC_SUPPORT_CLOCK_X2 |
@@ -202,7 +202,7 @@ const struct snd_motu_spec snd_motu_spec_traveler = {
 	.analog_out_ports = 8,
 };
 
-const struct snd_motu_spec snd_motu_spec_8pre = {
+static const struct snd_motu_spec motu_8pre = {
 	.name = "8pre",
 	.protocol = &snd_motu_protocol_v2,
 	// In tx, use coax chunks for mix-return 1/2. In rx, use coax chunks for
@@ -270,9 +270,9 @@ static const struct snd_motu_spec motu_4pre = {
 }
 
 static const struct ieee1394_device_id motu_id_table[] = {
-	SND_MOTU_DEV_ENTRY(0x000003, &motu_828mk2),
-	SND_MOTU_DEV_ENTRY(0x000009, &snd_motu_spec_traveler),
-	SND_MOTU_DEV_ENTRY(0x00000f, &snd_motu_spec_8pre),
+	SND_MOTU_DEV_ENTRY(0x000003, &snd_motu_spec_828mk2),
+	SND_MOTU_DEV_ENTRY(0x000009, &motu_traveler),
+	SND_MOTU_DEV_ENTRY(0x00000f, &motu_8pre),
 	SND_MOTU_DEV_ENTRY(0x000015, &motu_828mk3),	/* FireWire only. */
 	SND_MOTU_DEV_ENTRY(0x000035, &motu_828mk3),	/* Hybrid. */
 	SND_MOTU_DEV_ENTRY(0x000033, &motu_audio_express),

sound/firewire/motu/motu.h

@@ -130,8 +130,7 @@ struct snd_motu_spec {
 extern const struct snd_motu_protocol snd_motu_protocol_v2;
 extern const struct snd_motu_protocol snd_motu_protocol_v3;
 
-extern const struct snd_motu_spec snd_motu_spec_traveler;
-extern const struct snd_motu_spec snd_motu_spec_8pre;
+extern const struct snd_motu_spec snd_motu_spec_828mk2;
 
 int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
 		    enum amdtp_stream_direction dir,