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path: root/drivers/media/platform/vivid/vivid-rds-gen.c
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Diffstat (limited to 'drivers/media/platform/vivid/vivid-rds-gen.c')
-rw-r--r--drivers/media/platform/vivid/vivid-rds-gen.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/drivers/media/platform/vivid/vivid-rds-gen.c b/drivers/media/platform/vivid/vivid-rds-gen.c
new file mode 100644
index 0000000..c382343
--- /dev/null
+++ b/drivers/media/platform/vivid/vivid-rds-gen.c
@@ -0,0 +1,166 @@
+/*
+ * vivid-rds-gen.c - rds (radio data system) generator support functions.
+ *
+ * Copyright 2014 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/kernel.h>
+#include <linux/ktime.h>
+#include <linux/string.h>
+#include <linux/videodev2.h>
+
+#include "vivid-rds-gen.h"
+
+static u8 vivid_get_di(const struct vivid_rds_gen *rds, unsigned grp)
+{
+ switch (grp) {
+ case 0:
+ return (rds->dyn_pty << 2) | (grp & 3);
+ case 1:
+ return (rds->compressed << 2) | (grp & 3);
+ case 2:
+ return (rds->art_head << 2) | (grp & 3);
+ case 3:
+ return (rds->mono_stereo << 2) | (grp & 3);
+ }
+ return 0;
+}
+
+/*
+ * This RDS generator creates 57 RDS groups (one group == four RDS blocks).
+ * Groups 0-3, 22-25 and 44-47 (spaced 22 groups apart) are filled with a
+ * standard 0B group containing the PI code and PS name.
+ *
+ * Groups 4-19 and 26-41 use group 2A for the radio text.
+ *
+ * Group 56 contains the time (group 4A).
+ *
+ * All remaining groups use a filler group 15B block that just repeats
+ * the PI and PTY codes.
+ */
+void vivid_rds_generate(struct vivid_rds_gen *rds)
+{
+ struct v4l2_rds_data *data = rds->data;
+ unsigned grp;
+ struct tm tm;
+ unsigned date;
+ unsigned time;
+ int l;
+
+ for (grp = 0; grp < VIVID_RDS_GEN_GROUPS; grp++, data += VIVID_RDS_GEN_BLKS_PER_GRP) {
+ data[0].lsb = rds->picode & 0xff;
+ data[0].msb = rds->picode >> 8;
+ data[0].block = V4L2_RDS_BLOCK_A | (V4L2_RDS_BLOCK_A << 3);
+ data[1].lsb = rds->pty << 5;
+ data[1].msb = (rds->pty >> 3) | (rds->tp << 2);
+ data[1].block = V4L2_RDS_BLOCK_B | (V4L2_RDS_BLOCK_B << 3);
+ data[3].block = V4L2_RDS_BLOCK_D | (V4L2_RDS_BLOCK_D << 3);
+
+ switch (grp) {
+ case 0 ... 3:
+ case 22 ... 25:
+ case 44 ... 47: /* Group 0B */
+ data[1].lsb |= (rds->ta << 4) | (rds->ms << 3);
+ data[1].lsb |= vivid_get_di(rds, grp % 22);
+ data[1].msb |= 1 << 3;
+ data[2].lsb = rds->picode & 0xff;
+ data[2].msb = rds->picode >> 8;
+ data[2].block = V4L2_RDS_BLOCK_C_ALT | (V4L2_RDS_BLOCK_C_ALT << 3);
+ data[3].lsb = rds->psname[2 * (grp % 22) + 1];
+ data[3].msb = rds->psname[2 * (grp % 22)];
+ break;
+ case 4 ... 19:
+ case 26 ... 41: /* Group 2A */
+ data[1].lsb |= (grp - 4) % 22;
+ data[1].msb |= 4 << 3;
+ data[2].msb = rds->radiotext[4 * ((grp - 4) % 22)];
+ data[2].lsb = rds->radiotext[4 * ((grp - 4) % 22) + 1];
+ data[2].block = V4L2_RDS_BLOCK_C | (V4L2_RDS_BLOCK_C << 3);
+ data[3].msb = rds->radiotext[4 * ((grp - 4) % 22) + 2];
+ data[3].lsb = rds->radiotext[4 * ((grp - 4) % 22) + 3];
+ break;
+ case 56:
+ /*
+ * Group 4A
+ *
+ * Uses the algorithm from Annex G of the RDS standard
+ * EN 50067:1998 to convert a UTC date to an RDS Modified
+ * Julian Day.
+ */
+ time_to_tm(get_seconds(), 0, &tm);
+ l = tm.tm_mon <= 1;
+ date = 14956 + tm.tm_mday + ((tm.tm_year - l) * 1461) / 4 +
+ ((tm.tm_mon + 2 + l * 12) * 306001) / 10000;
+ time = (tm.tm_hour << 12) |
+ (tm.tm_min << 6) |
+ (sys_tz.tz_minuteswest >= 0 ? 0x20 : 0) |
+ (abs(sys_tz.tz_minuteswest) / 30);
+ data[1].lsb &= ~3;
+ data[1].lsb |= date >> 15;
+ data[1].msb |= 8 << 3;
+ data[2].lsb = (date << 1) & 0xfe;
+ data[2].lsb |= (time >> 16) & 1;
+ data[2].msb = (date >> 7) & 0xff;
+ data[2].block = V4L2_RDS_BLOCK_C | (V4L2_RDS_BLOCK_C << 3);
+ data[3].lsb = time & 0xff;
+ data[3].msb = (time >> 8) & 0xff;
+ break;
+ default: /* Group 15B */
+ data[1].lsb |= (rds->ta << 4) | (rds->ms << 3);
+ data[1].lsb |= vivid_get_di(rds, grp % 22);
+ data[1].msb |= 0x1f << 3;
+ data[2].lsb = rds->picode & 0xff;
+ data[2].msb = rds->picode >> 8;
+ data[2].block = V4L2_RDS_BLOCK_C_ALT | (V4L2_RDS_BLOCK_C_ALT << 3);
+ data[3].lsb = rds->pty << 5;
+ data[3].lsb |= (rds->ta << 4) | (rds->ms << 3);
+ data[3].lsb |= vivid_get_di(rds, grp % 22);
+ data[3].msb |= rds->pty >> 3;
+ data[3].msb |= 0x1f << 3;
+ break;
+ }
+ }
+}
+
+void vivid_rds_gen_fill(struct vivid_rds_gen *rds, unsigned freq,
+ bool alt)
+{
+ /* Alternate PTY between Info and Weather */
+ if (rds->use_rbds) {
+ rds->picode = 0x2e75; /* 'KLNX' call sign */
+ rds->pty = alt ? 29 : 2;
+ } else {
+ rds->picode = 0x8088;
+ rds->pty = alt ? 16 : 3;
+ }
+ rds->mono_stereo = true;
+ rds->art_head = false;
+ rds->compressed = false;
+ rds->dyn_pty = false;
+ rds->tp = true;
+ rds->ta = alt;
+ rds->ms = true;
+ snprintf(rds->psname, sizeof(rds->psname), "%6d.%1d",
+ freq / 16, ((freq & 0xf) * 10) / 16);
+ if (alt)
+ strlcpy(rds->radiotext,
+ " The Radio Data System can switch between different Radio Texts ",
+ sizeof(rds->radiotext));
+ else
+ strlcpy(rds->radiotext,
+ "An example of Radio Text as transmitted by the Radio Data System",
+ sizeof(rds->radiotext));
+}

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