ALSA: fireface: code refactoring to handle multiplier mode

Fireface 400/800 use three modes against the number of data channels in
data block for both tx/rx packets.

This commit adds refactoring for it. Some enumerators are added to
represent each of mode and a function is added to calculate the mode
from sampling frequency code (sfc).
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/fireface/ff-pcm.c

@@ -8,11 +8,6 @@
 
 #include "ff.h"
 
-static inline unsigned int get_multiplier_mode_with_index(unsigned int index)
-{
-	return ((int)index - 1) / 2;
-}
-
 static int hw_rule_rate(struct snd_pcm_hw_params *params,
 			struct snd_pcm_hw_rule *rule)
 {
@@ -24,10 +19,16 @@ static int hw_rule_rate(struct snd_pcm_hw_params *params,
 	struct snd_interval t = {
 		.min = UINT_MAX, .max = 0, .integer = 1
 	};
-	unsigned int i, mode;
+	unsigned int i;
 
 	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
-		mode = get_multiplier_mode_with_index(i);
+		enum snd_ff_stream_mode mode;
+		int err;
+
+		err = snd_ff_stream_get_multiplier_mode(i, &mode);
+		if (err < 0)
+			continue;
+
 		if (!snd_interval_test(c, pcm_channels[mode]))
 			continue;
 
@@ -49,10 +50,16 @@ static int hw_rule_channels(struct snd_pcm_hw_params *params,
 	struct snd_interval t = {
 		.min = UINT_MAX, .max = 0, .integer = 1
 	};
-	unsigned int i, mode;
+	unsigned int i;
 
 	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
-		mode = get_multiplier_mode_with_index(i);
+		enum snd_ff_stream_mode mode;
+		int err;
+
+		err = snd_ff_stream_get_multiplier_mode(i, &mode);
+		if (err < 0)
+			continue;
+
 		if (!snd_interval_test(r, amdtp_rate_table[i]))
 			continue;
 
@@ -66,7 +73,6 @@ static int hw_rule_channels(struct snd_pcm_hw_params *params,
 static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
 				     const unsigned int *pcm_channels)
 {
-	unsigned int mode;
 	unsigned int rate, channels;
 	int i;
 
@@ -76,7 +82,12 @@ static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
 	hw->rate_max = 0;
 
 	for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
-		mode = get_multiplier_mode_with_index(i);
+		enum snd_ff_stream_mode mode;
+		int err;
+
+		err = snd_ff_stream_get_multiplier_mode(i, &mode);
+		if (err < 0)
+			continue;
 
 		channels = pcm_channels[mode];
 		if (pcm_channels[mode] == 0)

sound/firewire/fireface/ff-stream.c

@@ -10,19 +10,23 @@
 
 #define CALLBACK_TIMEOUT_MS	200
 
-static int get_rate_mode(unsigned int rate, unsigned int *mode)
+int snd_ff_stream_get_multiplier_mode(enum cip_sfc sfc,
+				      enum snd_ff_stream_mode *mode)
 {
-	int i;
-
-	for (i = 0; i < CIP_SFC_COUNT; i++) {
-		if (amdtp_rate_table[i] == rate)
-			break;
-	}
-
-	if (i == CIP_SFC_COUNT)
+	static const enum snd_ff_stream_mode modes[] = {
+		[CIP_SFC_32000] = SND_FF_STREAM_MODE_LOW,
+		[CIP_SFC_44100] = SND_FF_STREAM_MODE_LOW,
+		[CIP_SFC_48000] = SND_FF_STREAM_MODE_LOW,
+		[CIP_SFC_88200] = SND_FF_STREAM_MODE_MID,
+		[CIP_SFC_96000] = SND_FF_STREAM_MODE_MID,
+		[CIP_SFC_176400] = SND_FF_STREAM_MODE_HIGH,
+		[CIP_SFC_192000] = SND_FF_STREAM_MODE_HIGH,
+	};
+
+	if (sfc >= CIP_SFC_COUNT)
 		return -EINVAL;
 
-	*mode = ((int)i - 1) / 2;
+	*mode = modes[sfc];
 
 	return 0;
 }
@@ -33,10 +37,18 @@ static int get_rate_mode(unsigned int rate, unsigned int *mode)
  */
 static int keep_resources(struct snd_ff *ff, unsigned int rate)
 {
-	int mode;
+	enum snd_ff_stream_mode mode;
+	int i;
 	int err;
 
-	err = get_rate_mode(rate, &mode);
+	for (i = 0; i < CIP_SFC_COUNT; ++i) {
+		if (amdtp_rate_table[i] == rate)
+			break;
+	}
+	if (i == CIP_SFC_COUNT)
+		return -EINVAL;
+
+	err = snd_ff_stream_get_multiplier_mode(i, &mode);
 	if (err < 0)
 		return err;
 
@@ -81,7 +93,7 @@ static int switch_fetching_mode(struct snd_ff *ff, bool enable)
 	int err;
 
 	count = 0;
-	for (i = 0; i < SND_FF_STREAM_MODES; ++i)
+	for (i = 0; i < SND_FF_STREAM_MODE_COUNT; ++i)
 		count = max(count, ff->spec->pcm_playback_channels[i]);
 
 	reg = kcalloc(count, sizeof(__le32), GFP_KERNEL);

sound/firewire/fireface/ff.h

@@ -31,8 +31,6 @@
 #include "../amdtp-stream.h"
 #include "../iso-resources.h"
 
-#define SND_FF_STREAM_MODES		3
-
 #define SND_FF_MAXIMIM_MIDI_QUADS	9
 #define SND_FF_IN_MIDI_PORTS		2
 #define SND_FF_OUT_MIDI_PORTS		2
@@ -42,6 +40,13 @@
 #define SND_FF_REG_FETCH_PCM_FRAMES	0x0000801c0000ull
 #define SND_FF_REG_CLOCK_CONFIG		0x0000801c0004ull
 
+enum snd_ff_stream_mode {
+	SND_FF_STREAM_MODE_LOW = 0,
+	SND_FF_STREAM_MODE_MID,
+	SND_FF_STREAM_MODE_HIGH,
+	SND_FF_STREAM_MODE_COUNT,
+};
+
 enum snd_ff_reg_type {
 	SND_FF_REG_TYPE_MIDI_HIGH_ADDR = 0,
 	SND_FF_REG_TYPE_COUNT,
@@ -51,8 +56,8 @@ struct snd_ff_protocol;
 struct snd_ff_spec {
 	const char *const name;
 
-	const unsigned int pcm_capture_channels[SND_FF_STREAM_MODES];
-	const unsigned int pcm_playback_channels[SND_FF_STREAM_MODES];
+	const unsigned int pcm_capture_channels[SND_FF_STREAM_MODE_COUNT];
+	const unsigned int pcm_playback_channels[SND_FF_STREAM_MODE_COUNT];
 
 	unsigned int midi_in_ports;
 	unsigned int midi_out_ports;
@@ -129,6 +134,8 @@ int amdtp_ff_add_pcm_hw_constraints(struct amdtp_stream *s,
 int amdtp_ff_init(struct amdtp_stream *s, struct fw_unit *unit,
 		  enum amdtp_stream_direction dir);
 
+int snd_ff_stream_get_multiplier_mode(enum cip_sfc sfc,
+				      enum snd_ff_stream_mode *mode);
 int snd_ff_stream_init_duplex(struct snd_ff *ff);
 void snd_ff_stream_destroy_duplex(struct snd_ff *ff);
 int snd_ff_stream_start_duplex(struct snd_ff *ff, unsigned int rate);