[media] rc: rc-ir-raw: Add pulse-distance modulation helper
Add IR encoding helper for pulse-distance modulation as used by the NEC
protocol.
Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Sean Young <sean@mess.org>
Cc: Antti Seppälä <a.seppala@gmail.com>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index 85ac507..58039e6 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -324,6 +324,65 @@
EXPORT_SYMBOL(ir_raw_gen_manchester);
/**
+ * ir_raw_gen_pd() - Encode data to raw events with pulse-distance modulation.
+ * @ev: Pointer to pointer to next free event. *@ev is incremented for
+ * each raw event filled.
+ * @max: Maximum number of raw events to fill.
+ * @timings: Pulse distance modulation timings.
+ * @n: Number of bits of data.
+ * @data: Data bits to encode.
+ *
+ * Encodes the @n least significant bits of @data using pulse-distance
+ * modulation with the timing characteristics described by @timings, writing up
+ * to @max raw IR events using the *@ev pointer.
+ *
+ * Returns: 0 on success.
+ * -ENOBUFS if there isn't enough space in the array to fit the
+ * full encoded data. In this case all @max events will have been
+ * written.
+ */
+int ir_raw_gen_pd(struct ir_raw_event **ev, unsigned int max,
+ const struct ir_raw_timings_pd *timings,
+ unsigned int n, u64 data)
+{
+ int i;
+ int ret;
+ unsigned int space;
+
+ if (timings->header_pulse) {
+ ret = ir_raw_gen_pulse_space(ev, &max, timings->header_pulse,
+ timings->header_space);
+ if (ret)
+ return ret;
+ }
+
+ if (timings->msb_first) {
+ for (i = n - 1; i >= 0; --i) {
+ space = timings->bit_space[(data >> i) & 1];
+ ret = ir_raw_gen_pulse_space(ev, &max,
+ timings->bit_pulse,
+ space);
+ if (ret)
+ return ret;
+ }
+ } else {
+ for (i = 0; i < n; ++i, data >>= 1) {
+ space = timings->bit_space[data & 1];
+ ret = ir_raw_gen_pulse_space(ev, &max,
+ timings->bit_pulse,
+ space);
+ if (ret)
+ return ret;
+ }
+ }
+
+ ret = ir_raw_gen_pulse_space(ev, &max, timings->trailer_pulse,
+ timings->trailer_space);
+ return ret;
+}
+EXPORT_SYMBOL(ir_raw_gen_pd);
+
+/**
* ir_raw_encode_scancode() - Encode a scancode as raw events
*
* @protocol: protocol