Commit caec0984 authored by James Hogan's avatar James Hogan Committed by Mauro Carvalho Chehab
Browse files

[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: default avatarJames Hogan <james@albanarts.com>
Signed-off-by: default avatarSean Young <sean@mess.org>
Cc: Antti Seppälä <a.seppala@gmail.com>
Cc: David Härdeman <david@hardeman.nu>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@s-opensource.com>
parent 844a4f45

drivers/media/rc/rc-core-priv.h

+52 −0
Original line number Diff line number Diff line
@@ -187,6 +187,58 @@ int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, 
			  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

 */

drivers/media/rc/rc-ir-raw.c

+59 −0
Original line number Diff line number Diff line
@@ -323,6 +323,65 @@ int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, 
}

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

 *