[Sound-open-firmware] [PATCH] [RFC]platform: calculate the percentage of cpu cycle

[Wu Zhigang]

calculate the percentage of cpu cyle based on
the CCOUNT register. which can tell the percentage
of cpu cycle usage.

Signed-off-by: Wu Zhigang <zhigang.wu at linux.intel.com>
---
 src/audio/dai.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/audio/dai.c b/src/audio/dai.c
index 99749d1..7811e38 100644
--- a/src/audio/dai.c
+++ b/src/audio/dai.c
@@ -72,6 +72,21 @@ struct dai_data {
 	uint64_t wallclock;	/* wall clock at stream start */
 };
 
+/* for apollolake, it is 400MHz per 1s */
+#define CPU_CYCLE_PER_MS	400000
+
+static void calc_mcps(struct pipeline *p)
+{
+	uint32_t cpu_cycle = 0;
+	uint32_t deta = 0;
+
+	__asm__ __volatile__ ("rsr %0, CCOUNT" : "=a" (cpu_cycle) : : "memory");
+	deta = cpu_cycle - p->cpu_cycle;
+	p->cpu_cycle = cpu_cycle;
+	deta = (deta * 100) / CPU_CYCLE_PER_MS;
+	trace_error_value(deta); /* the percentage of the cpu cycle in 1ms */
+}
+
 /* this is called by DMA driver every time descriptor has completed */
 static void dai_dma_cb(void *data, uint32_t type, struct dma_sg_elem *next)
 {
@@ -81,6 +96,8 @@ static void dai_dma_cb(void *data, uint32_t type, struct dma_sg_elem *next)
 
 	tracev_dai("irq");
 
+	calc_mcps(dev->pipeline);
+
 	/* stop dma copy for pause/stop/xrun */
 	if (dev->state != COMP_STATE_ACTIVE || dd->xrun) {
 
-- 
2.17.1