Commit 1d184b0b authored by James Hogan's avatar James Hogan Committed by Mauro Carvalho Chehab
Browse files

[media] media: rc: add raw decoder for Sharp protocol 



Add a raw decoder for the Sharp protocol. It uses a pulse distance
modulation with a pulse of 320us and a bit period of 2ms for a logical 1
and 1ms for a logical 0. The first part of the message consists of a
5-bit address, an 8-bit command, and two other bits, followed by a 40ms
gap before the echo message which is an inverted version of the main
message except for the address bits.

Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
Cc: linux-media@vger.kernel.org
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 38f2a214

drivers/media/rc/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -106,6 +106,15 @@ config IR_SANYO_DECODER 
	   uses the Sanyo protocol (Sanyo, Aiwa, Chinon remotes),

	   and you need software decoding support.



config IR_SHARP_DECODER

	tristate "Enable IR raw decoder for the Sharp protocol"

	depends on RC_CORE

	default y



	---help---

	   Enable this option if you have an infrared remote control which

	   uses the Sharp protocol, and you need software decoding support.



config IR_MCE_KBD_DECODER

	tristate "Enable IR raw decoder for the MCE keyboard/mouse protocol"

	depends on RC_CORE

drivers/media/rc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ obj-$(CONFIG_IR_JVC_DECODER) += ir-jvc-decoder.o 
obj-$(CONFIG_IR_SONY_DECODER) += ir-sony-decoder.o

obj-$(CONFIG_IR_RC5_SZ_DECODER) += ir-rc5-sz-decoder.o

obj-$(CONFIG_IR_SANYO_DECODER) += ir-sanyo-decoder.o

obj-$(CONFIG_IR_SHARP_DECODER) += ir-sharp-decoder.o

obj-$(CONFIG_IR_MCE_KBD_DECODER) += ir-mce_kbd-decoder.o

obj-$(CONFIG_IR_LIRC_CODEC) += ir-lirc-codec.o

drivers/media/rc/ir-sharp-decoder.c

0 → 100644
+200 −0
Original line number Diff line number Diff line 
/* ir-sharp-decoder.c - handle Sharp IR Pulse/Space protocol

 *

 * Copyright (C) 2013-2014 Imagination Technologies Ltd.

 *

 * Based on NEC decoder:

 * Copyright (C) 2010 by Mauro Carvalho Chehab <mchehab@redhat.com>

 *

 * This program is free software; you can 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.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 */



#include <linux/bitrev.h>

#include <linux/module.h>

#include "rc-core-priv.h"



#define SHARP_NBITS		15

#define SHARP_UNIT		40000  /* ns */

#define SHARP_BIT_PULSE		(8    * SHARP_UNIT) /* 320us */

#define SHARP_BIT_0_PERIOD	(25   * SHARP_UNIT) /* 1ms (680us space) */

#define SHARP_BIT_1_PERIOD	(50   * SHARP_UNIT) /* 2ms (1680ms space) */

#define SHARP_ECHO_SPACE	(1000 * SHARP_UNIT) /* 40 ms */

#define SHARP_TRAILER_SPACE	(125  * SHARP_UNIT) /* 5 ms (even longer) */



enum sharp_state {

	STATE_INACTIVE,

	STATE_BIT_PULSE,

	STATE_BIT_SPACE,

	STATE_TRAILER_PULSE,

	STATE_ECHO_SPACE,

	STATE_TRAILER_SPACE,

};



/**

 * ir_sharp_decode() - Decode one Sharp pulse or space

 * @dev:	the struct rc_dev descriptor of the device

 * @duration:	the struct ir_raw_event descriptor of the pulse/space

 *

 * This function returns -EINVAL if the pulse violates the state machine

 */

static int ir_sharp_decode(struct rc_dev *dev, struct ir_raw_event ev)

{

	struct sharp_dec *data = &dev->raw->sharp;

	u32 msg, echo, address, command, scancode;



	if (!(dev->enabled_protocols & RC_BIT_SHARP))

		return 0;



	if (!is_timing_event(ev)) {

		if (ev.reset)

			data->state = STATE_INACTIVE;

		return 0;

	}



	IR_dprintk(2, "Sharp decode started at state %d (%uus %s)\n",

		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));



	switch (data->state) {



	case STATE_INACTIVE:

		if (!ev.pulse)

			break;



		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,

			       SHARP_BIT_PULSE / 2))

			break;



		data->count = 0;

		data->pulse_len = ev.duration;

		data->state = STATE_BIT_SPACE;

		return 0;



	case STATE_BIT_PULSE:

		if (!ev.pulse)

			break;



		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,

			       SHARP_BIT_PULSE / 2))

			break;



		data->pulse_len = ev.duration;

		data->state = STATE_BIT_SPACE;

		return 0;



	case STATE_BIT_SPACE:

		if (ev.pulse)

			break;



		data->bits <<= 1;

		if (eq_margin(data->pulse_len + ev.duration, SHARP_BIT_1_PERIOD,

			      SHARP_BIT_PULSE * 2))

			data->bits |= 1;

		else if (!eq_margin(data->pulse_len + ev.duration,

				    SHARP_BIT_0_PERIOD, SHARP_BIT_PULSE * 2))

			break;

		data->count++;



		if (data->count == SHARP_NBITS ||

		    data->count == SHARP_NBITS * 2)

			data->state = STATE_TRAILER_PULSE;

		else

			data->state = STATE_BIT_PULSE;



		return 0;



	case STATE_TRAILER_PULSE:

		if (!ev.pulse)

			break;



		if (!eq_margin(ev.duration, SHARP_BIT_PULSE,

			       SHARP_BIT_PULSE / 2))

			break;



		if (data->count == SHARP_NBITS) {

			/* exp,chk bits should be 1,0 */

			if ((data->bits & 0x3) != 0x2)

				break;

			data->state = STATE_ECHO_SPACE;

		} else {

			data->state = STATE_TRAILER_SPACE;

		}

		return 0;



	case STATE_ECHO_SPACE:

		if (ev.pulse)

			break;



		if (!eq_margin(ev.duration, SHARP_ECHO_SPACE,

			       SHARP_ECHO_SPACE / 4))

			break;



		data->state = STATE_BIT_PULSE;



		return 0;



	case STATE_TRAILER_SPACE:

		if (ev.pulse)

			break;



		if (!geq_margin(ev.duration, SHARP_TRAILER_SPACE,

				SHARP_BIT_PULSE / 2))

			break;



		/* Validate - command, ext, chk should be inverted in 2nd */

		msg = (data->bits >> 15) & 0x7fff;

		echo = data->bits & 0x7fff;

		if ((msg ^ echo) != 0x3ff) {

			IR_dprintk(1,

				   "Sharp checksum error: received 0x%04x, 0x%04x\n",

				   msg, echo);

			break;

		}



		address = bitrev8((msg >> 7) & 0xf8);

		command = bitrev8((msg >> 2) & 0xff);



		scancode = address << 8 | command;

		IR_dprintk(1, "Sharp scancode 0x%04x\n", scancode);



		rc_keydown(dev, scancode, 0);

		data->state = STATE_INACTIVE;

		return 0;

	}



	IR_dprintk(1, "Sharp decode failed at count %d state %d (%uus %s)\n",

		   data->count, data->state, TO_US(ev.duration),

		   TO_STR(ev.pulse));

	data->state = STATE_INACTIVE;

	return -EINVAL;

}



static struct ir_raw_handler sharp_handler = {

	.protocols	= RC_BIT_SHARP,

	.decode		= ir_sharp_decode,

};



static int __init ir_sharp_decode_init(void)

{

	ir_raw_handler_register(&sharp_handler);



	pr_info("IR Sharp protocol handler initialized\n");

	return 0;

}



static void __exit ir_sharp_decode_exit(void)

{

	ir_raw_handler_unregister(&sharp_handler);

}



module_init(ir_sharp_decode_init);

module_exit(ir_sharp_decode_exit);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("James Hogan <james.hogan@imgtec.com>");

MODULE_DESCRIPTION("Sharp IR protocol decoder");

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

+6 −0
Original line number Diff line number Diff line
@@ -88,6 +88,12 @@ struct ir_raw_event_ctrl { 
		unsigned count;

		u64 bits;

	} sanyo;

	struct sharp_dec {

		int state;

		unsigned count;

		u32 bits;

		unsigned int pulse_len;

	} sharp;

	struct mce_kbd_dec {

		struct input_dev *idev;

		struct timer_list rx_timeout;

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