X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=drivers%2Fmedia%2Fplatform%2Fvivid%2Fvivid-sdr-cap.c;h=d0c26577c06ea29139942211ea5863982fe1ff43;hb=60f68735441ce01858c81d32071f7df41c1691e3;hp=d2f2188a0efe78ac7f13bab293b00dc53d6084eb;hpb=8c4de9bc2041229fb778e0c47e32585b6f6b1d09;p=firefly-linux-kernel-4.4.55.git

diff --git a/drivers/media/platform/vivid/vivid-sdr-cap.c b/drivers/media/platform/vivid/vivid-sdr-cap.c
index d2f2188a0efe..d0c26577c06e 100644
--- a/drivers/media/platform/vivid/vivid-sdr-cap.c
+++ b/drivers/media/platform/vivid/vivid-sdr-cap.c
@@ -22,6 +22,7 @@
 #include <linux/delay.h>
 #include <linux/kthread.h>
 #include <linux/freezer.h>
+#include <linux/math64.h>
 #include <linux/videodev2.h>
 #include <linux/v4l2-dv-timings.h>
 #include <media/v4l2-common.h>
@@ -40,7 +41,7 @@ struct vivid_format {
 };
 
 /* format descriptions for capture and preview */
-static struct vivid_format formats[] = {
+static const struct vivid_format formats[] = {
 	{
 		.pixelformat	= V4L2_SDR_FMT_CU8,
 		.buffersize	= SDR_CAP_SAMPLES_PER_BUF * 2,
@@ -488,47 +489,42 @@ int vidioc_try_fmt_sdr_cap(struct file *file, void *fh, struct v4l2_format *f)
 #define FIXP_N    (15)
 #define FIXP_FRAC (1 << FIXP_N)
 #define FIXP_2PI  ((int)(2 * 3.141592653589 * FIXP_FRAC))
+#define M_100000PI (3.14159 * 100000)
 
 void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
 {
 	u8 *vbuf = vb2_plane_vaddr(&buf->vb, 0);
 	unsigned long i;
 	unsigned long plane_size = vb2_plane_size(&buf->vb, 0);
+	s64 s64tmp;
 	s32 src_phase_step;
 	s32 mod_phase_step;
 	s32 fixp_i;
 	s32 fixp_q;
 
-	/*
-	 * TODO: Generated beep tone goes very crackly when sample rate is
-	 * increased to ~1Msps or more. That is because of huge rounding error
-	 * of phase angle caused by used cosine implementation.
-	 */
-
 	/* calculate phase step */
 	#define BEEP_FREQ 1000 /* 1kHz beep */
 	src_phase_step = DIV_ROUND_CLOSEST(FIXP_2PI * BEEP_FREQ,
-			dev->sdr_adc_freq);
+					   dev->sdr_adc_freq);
 
 	for (i = 0; i < plane_size; i += 2) {
 		mod_phase_step = fixp_cos32_rad(dev->sdr_fixp_src_phase,
 						FIXP_2PI) >> (31 - FIXP_N);
 
 		dev->sdr_fixp_src_phase += src_phase_step;
-		dev->sdr_fixp_mod_phase += mod_phase_step / 4;
+		s64tmp = (s64) mod_phase_step * dev->sdr_fm_deviation;
+		dev->sdr_fixp_mod_phase += div_s64(s64tmp, M_100000PI);
 
 		/*
-		 * Transfer phases to [0 / 2xPI] in order to avoid variable
+		 * Transfer phase angle to [0, 2xPI] in order to avoid variable
 		 * overflow and make it suitable for cosine implementation
 		 * used, which does not support negative angles.
 		 */
-		while (dev->sdr_fixp_mod_phase < FIXP_2PI)
-			dev->sdr_fixp_mod_phase += FIXP_2PI;
-		while (dev->sdr_fixp_mod_phase > FIXP_2PI)
-			dev->sdr_fixp_mod_phase -= FIXP_2PI;
+		dev->sdr_fixp_src_phase %= FIXP_2PI;
+		dev->sdr_fixp_mod_phase %= FIXP_2PI;
 
-		while (dev->sdr_fixp_src_phase > FIXP_2PI)
-			dev->sdr_fixp_src_phase -= FIXP_2PI;
+		if (dev->sdr_fixp_mod_phase < 0)
+			dev->sdr_fixp_mod_phase += FIXP_2PI;
 
 		fixp_i = fixp_cos32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
 		fixp_q = fixp_sin32_rad(dev->sdr_fixp_mod_phase, FIXP_2PI);
@@ -540,7 +536,7 @@ void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
 
 		switch (dev->sdr_pixelformat) {
 		case V4L2_SDR_FMT_CU8:
-			/* convert 'fixp float' to u8 */
+			/* convert 'fixp float' to u8 [0, +255] */
 			/* u8 = X * 127.5 + 127.5; X is float [-1.0, +1.0] */
 			fixp_i = fixp_i * 1275 + FIXP_FRAC * 1275;
 			fixp_q = fixp_q * 1275 + FIXP_FRAC * 1275;
@@ -548,9 +544,10 @@ void vivid_sdr_cap_process(struct vivid_dev *dev, struct vivid_buffer *buf)
 			*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
 			break;
 		case V4L2_SDR_FMT_CS8:
-			/* convert 'fixp float' to s8 */
-			fixp_i = fixp_i * 1275;
-			fixp_q = fixp_q * 1275;
+			/* convert 'fixp float' to s8 [-128, +127] */
+			/* s8 = X * 127.5 - 0.5; X is float [-1.0, +1.0] */
+			fixp_i = fixp_i * 1275 - FIXP_FRAC * 5;
+			fixp_q = fixp_q * 1275 - FIXP_FRAC * 5;
 			*vbuf++ = DIV_ROUND_CLOSEST(fixp_i, FIXP_FRAC * 10);
 			*vbuf++ = DIV_ROUND_CLOSEST(fixp_q, FIXP_FRAC * 10);
 			break;