[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-core-priv.h b/drivers/media/rc/rc-core-priv.h
index b8d40e6..2471a3c 100644
--- a/drivers/media/rc/rc-core-priv.h
+++ b/drivers/media/rc/rc-core-priv.h
@@ -187,6 +187,58 @@
const struct ir_raw_timings_manchester *timings,
unsigned int n, unsigned int data);
+/**
+ * ir_raw_gen_pulse_space() - generate pulse and space raw events.
+ * @ev: Pointer to pointer to next free raw event.
+ * Will be incremented for each raw event written.
+ * @max: Pointer to number of raw events available in buffer.
+ * Will be decremented for each raw event written.
+ * @pulse_width: Width of pulse in ns.
+ * @space_width: Width of space in ns.
+ *
+ * Returns: 0 on success.
+ * -ENOBUFS if there isn't enough buffer space to write both raw
+ * events. In this case @max events will have been written.
+ */
+static inline int ir_raw_gen_pulse_space(struct ir_raw_event **ev,
+ unsigned int *max,
+ unsigned int pulse_width,
+ unsigned int space_width)
+{
+ if (!*max)
+ return -ENOBUFS;
+ init_ir_raw_event_duration((*ev)++, 1, pulse_width);
+ if (!--*max)
+ return -ENOBUFS;
+ init_ir_raw_event_duration((*ev)++, 0, space_width);
+ --*max;
+ return 0;
+}
+
+/**
+ * struct ir_raw_timings_pd - pulse-distance modulation timings
+ * @header_pulse: duration of header pulse in ns (0 for none)
+ * @header_space: duration of header space in ns
+ * @bit_pulse: duration of bit pulse in ns
+ * @bit_space: duration of bit space (for logic 0 and 1) in ns
+ * @trailer_pulse: duration of trailer pulse in ns
+ * @trailer_space: duration of trailer space in ns
+ * @msb_first: 1 if most significant bit is sent first
+ */
+struct ir_raw_timings_pd {
+ unsigned int header_pulse;
+ unsigned int header_space;
+ unsigned int bit_pulse;
+ unsigned int bit_space[2];
+ unsigned int trailer_pulse;
+ unsigned int trailer_space;
+ unsigned int msb_first:1;
+};
+
+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);
+
/*
* Routines from rc-raw.c to be used internally and by decoders
*/
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