ALSA: firewire-lib: code refactoring for helper function to compute OHCI 1394 cycle

Some macros and functions are renamed so that they compute isochronous
cycle within maximum count of second in isochronous context of 1394
OHCI.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20210518130048.146596-5-o-takashi@sakamocchi.jpSigned-off-by: Takashi Iwai <tiwai@suse.de>

sound/firewire/amdtp-stream.c

@@ -20,7 +20,7 @@
 #define CYCLES_PER_SECOND	8000
 #define TICKS_PER_SECOND	(TICKS_PER_CYCLE * CYCLES_PER_SECOND)
 
-#define OHCI_MAX_SECOND		8
+#define OHCI_SECOND_MODULUS		8
 
 /* Always support Linux tracing subsystem. */
 #define CREATE_TRACE_POINTS
@@ -688,17 +688,17 @@ static int parse_ir_ctx_header(struct amdtp_stream *s, unsigned int cycle,
 // In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
 // the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
 // it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
-static inline u32 compute_cycle_count(__be32 ctx_header_tstamp)
+static inline u32 compute_ohci_cycle_count(__be32 ctx_header_tstamp)
 {
 	u32 tstamp = be32_to_cpu(ctx_header_tstamp) & HEADER_TSTAMP_MASK;
 	return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
 }
 
-static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
+static inline u32 increment_ohci_cycle_count(u32 cycle, unsigned int addend)
 {
 	cycle += addend;
-	if (cycle >= OHCI_MAX_SECOND * CYCLES_PER_SECOND)
-		cycle -= OHCI_MAX_SECOND * CYCLES_PER_SECOND;
+	if (cycle >= OHCI_SECOND_MODULUS * CYCLES_PER_SECOND)
+		cycle -= OHCI_SECOND_MODULUS * CYCLES_PER_SECOND;
 	return cycle;
 }
 
@@ -706,11 +706,11 @@ static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
 // This module queued the same number of isochronous cycle as the size of queue
 // to kip isochronous cycle, therefore it's OK to just increment the cycle by
 // the size of queue for scheduled cycle.
-static inline u32 compute_it_cycle(const __be32 ctx_header_tstamp,
-				   unsigned int queue_size)
+static inline u32 compute_ohci_it_cycle(const __be32 ctx_header_tstamp,
+					unsigned int queue_size)
 {
-	u32 cycle = compute_cycle_count(ctx_header_tstamp);
-	return increment_cycle_count(cycle, queue_size);
+	u32 cycle = compute_ohci_cycle_count(ctx_header_tstamp);
+	return increment_ohci_cycle_count(cycle, queue_size);
 }
 
 static int generate_device_pkt_descs(struct amdtp_stream *s,
@@ -731,7 +731,7 @@ static int generate_device_pkt_descs(struct amdtp_stream *s,
 		unsigned int data_blocks;
 		unsigned int syt;
 
-		cycle = compute_cycle_count(ctx_header[1]);
+		cycle = compute_ohci_cycle_count(ctx_header[1]);
 
 		err = parse_ir_ctx_header(s, cycle, ctx_header, &payload_length,
 					  &data_blocks, &dbc, &syt, packet_index, i);
@@ -784,7 +784,7 @@ static void generate_pkt_descs(struct amdtp_stream *s, struct pkt_desc *descs,
 		const struct seq_desc *seq = seq_descs + seq_index;
 		unsigned int syt;
 
-		desc->cycle = compute_it_cycle(*ctx_header, s->queue_size);
+		desc->cycle = compute_ohci_it_cycle(*ctx_header, s->queue_size);
 
 		syt = seq->syt_offset;
 		if (syt != CIP_SYT_NO_INFO) {
@@ -1025,11 +1025,11 @@ static void amdtp_stream_first_callback(struct fw_iso_context *context,
 	wake_up(&s->callback_wait);
 
 	if (s->direction == AMDTP_IN_STREAM) {
-		cycle = compute_cycle_count(ctx_header[1]);
+		cycle = compute_ohci_cycle_count(ctx_header[1]);
 
 		context->callback.sc = in_stream_callback;
 	} else {
-		cycle = compute_it_cycle(*ctx_header, s->queue_size);
+		cycle = compute_ohci_it_cycle(*ctx_header, s->queue_size);
 
 		if (s == s->domain->irq_target)
 			context->callback.sc = irq_target_callback;