Add support for interleaved R/G samples

This is useful for transmitting complex I/Q data on the
red and green DACs

1 files changed, 44 insertions, 7 deletions

diff --git a/src/libosmo-fl2k.c b/src/libosmo-fl2k.c
index 0285f9a..09380b6 100644
--- a/src/libosmo-fl2k.c
+++ b/src/libosmo-fl2k.c
@@ -767,6 +767,37 @@ static void *fl2k_usb_worker(void *arg)
 }
 
 /* Buffer format conversion functions for R, G, B DACs */
+static inline void fl2k_convert_rg_interleaved(
+				  char *out,
+				  char *in,
+				  uint32_t len,
+				  uint8_t offset)
+{
+	unsigned int i, j = 0;
+
+	if (!in || !out)
+		return;
+
+	for (i = 0; i < len; i += 24) {
+		out[i+ 6] = in[j++] + offset;
+		out[i+ 5] = in[j++] + offset;
+		out[i+ 1] = in[j++] + offset;
+		out[i+ 0] = in[j++] + offset;
+		out[i+12] = in[j++] + offset;
+		out[i+ 3] = in[j++] + offset;
+		out[i+15] = in[j++] + offset;
+		out[i+14] = in[j++] + offset;
+		out[i+10] = in[j++] + offset;
+		out[i+ 9] = in[j++] + offset;
+		out[i+21] = in[j++] + offset;
+		out[i+20] = in[j++] + offset;
+		out[i+16] = in[j++] + offset;
+		out[i+23] = in[j++] + offset;
+		out[i+19] = in[j++] + offset;
+		out[i+18] = in[j++] + offset;
+	}
+}
+
 static inline void fl2k_convert_r(char *out,
 				  char *in,
 				  uint32_t len,
@@ -882,15 +913,21 @@ static void *fl2k_sample_worker(void *arg)
 		xfer_info = (fl2k_xfer_info_t *)xfer->user_data;
 		out_buf = (char *)xfer->buffer;
 
-		/* Re-arrange and copy bytes in buffer for DACs */
-		fl2k_convert_r(out_buf, data_info.r_buf, dev->xfer_buf_len,
-			       data_info.sampletype_signed ? 128 : 0);
+		if (data_info.iq_buf) {
+			/* Re-arrange interleaved samples and copy bytes in buffer for DACs */
+			fl2k_convert_rg_interleaved(out_buf, data_info.iq_buf,
+					dev->xfer_buf_len, data_info.sampletype_signed ? 128 : 0);
+		} else {
+			/* Re-arrange and copy bytes in buffer for DACs */
+			fl2k_convert_r(out_buf, data_info.r_buf, dev->xfer_buf_len,
+					data_info.sampletype_signed ? 128 : 0);
 
-		fl2k_convert_g(out_buf, data_info.g_buf, dev->xfer_buf_len,
-			       data_info.sampletype_signed ? 128 : 0);
+			fl2k_convert_g(out_buf, data_info.g_buf, dev->xfer_buf_len,
+					data_info.sampletype_signed ? 128 : 0);
 
-		fl2k_convert_b(out_buf, data_info.b_buf, dev->xfer_buf_len,
-			       data_info.sampletype_signed ? 128 : 0);
+			fl2k_convert_b(out_buf, data_info.b_buf, dev->xfer_buf_len,
+					data_info.sampletype_signed ? 128 : 0);
+		}
 
 		xfer_info->seq = buf_cnt++;
 		xfer_info->state = BUF_FILLED;