drivers/media/IR/ir-nec-decoder.c - kernel/msm-4.9 - Gitiles

 /* ir-nec-decoder.c - handle NEC IR Pulse/Space protocol
  *
  * 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 <media/ir-core.h>

 #define NEC_NBITS		32
 #define NEC_UNIT		559979 /* ns */
 #define NEC_HEADER_MARK		(16 * NEC_UNIT)
 #define NEC_HEADER_SPACE	(8 * NEC_UNIT)
 #define NEC_REPEAT_SPACE	(4 * NEC_UNIT)
 #define NEC_MARK		(NEC_UNIT)
 #define NEC_0_SPACE		(NEC_UNIT)
 #define NEC_1_SPACE		(3 * NEC_UNIT)

 /* Used to register nec_decoder clients */
 static LIST_HEAD(decoder_list);
 static spinlock_t decoder_lock;

 enum nec_state {
 	STATE_INACTIVE,
 	STATE_HEADER_MARK,
 	STATE_HEADER_SPACE,
 	STATE_MARK,
 	STATE_SPACE,
 	STATE_TRAILER_MARK,
 	STATE_TRAILER_SPACE,
 };

 struct nec_code {
 	u8	address;
 	u8	not_address;
 	u8	command;
 	u8	not_command;
 };

 struct decoder_data {
 	struct list_head	list;
 	struct ir_input_dev	*ir_dev;
 	int			enabled:1;

 	/* State machine control */
 	enum nec_state		state;
 	struct nec_code		nec_code;
 	unsigned		count;
 };


 /**
  * get_decoder_data()	- gets decoder data
  * @input_dev:	input device
  *
  * Returns the struct decoder_data that corresponds to a device
  */

 static struct decoder_data *get_decoder_data(struct  ir_input_dev *ir_dev)
 {
 	struct decoder_data *data = NULL;

 	spin_lock(&decoder_lock);
 	list_for_each_entry(data, &decoder_list, list) {
 		if (data->ir_dev == ir_dev)
 			break;
 	}
 	spin_unlock(&decoder_lock);
 	return data;
 }

 static ssize_t store_enabled(struct device *d,
 			     struct device_attribute *mattr,
 			     const char *buf,
 			     size_t len)
 {
 	unsigned long value;
 	struct ir_input_dev *ir_dev = dev_get_drvdata(d);
 	struct decoder_data *data = get_decoder_data(ir_dev);

 	if (!data)
 		return -EINVAL;

 	if (strict_strtoul(buf, 10, &value) || value > 1)
 		return -EINVAL;

 	data->enabled = value;

 	return len;
 }

 static ssize_t show_enabled(struct device *d,
 			     struct device_attribute *mattr, char *buf)
 {
 	struct ir_input_dev *ir_dev = dev_get_drvdata(d);
 	struct decoder_data *data = get_decoder_data(ir_dev);

 	if (!data)
 		return -EINVAL;

 	if (data->enabled)
 		return sprintf(buf, "1\n");
 	else
 	return sprintf(buf, "0\n");
 }

 static DEVICE_ATTR(enabled, S_IRUGO | S_IWUSR, show_enabled, store_enabled);

 static struct attribute *decoder_attributes[] = {
 	&dev_attr_enabled.attr,
 	NULL
 };

 static struct attribute_group decoder_attribute_group = {
 	.name	= "nec_decoder",
 	.attrs	= decoder_attributes,
 };


 /**
  * ir_nec_decode() - Decode one NEC pulse or space
  * @input_dev:	the struct input_dev descriptor of the device
  * @ev:		event array with type/duration of pulse/space
  *
  * This function returns -EINVAL if the pulse violates the state machine
  */
 static int ir_nec_decode(struct input_dev *input_dev,
 			 struct ir_raw_event *ev)
 {
 	struct decoder_data *data;
 	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
 	int bit, last_bit;

 	data = get_decoder_data(ir_dev);
 	if (!data)
 		return -EINVAL;

 	if (!data->enabled)
 		return 0;

 	/* Except for the initial event, what matters is the previous bit */
 	bit = (ev->type & IR_PULSE) ? 1 : 0;

 	last_bit = !bit;

 	/* Discards spurious space last_bits when inactive */

 	/* Very long delays are considered as start events */
 	if (ev->delta.tv_nsec > NEC_HEADER_MARK + NEC_HEADER_SPACE - NEC_UNIT / 2)
 		data->state = STATE_INACTIVE;

 	if (ev->type & IR_START_EVENT)
 		data->state = STATE_INACTIVE;

 	switch (data->state) {
 	case STATE_INACTIVE:
 		if (!bit)		/* PULSE marks the start event */
 			return 0;

 		data->count = 0;
 		data->state = STATE_HEADER_MARK;
 		memset (&data->nec_code, 0, sizeof(data->nec_code));
 		return 0;
 	case STATE_HEADER_MARK:
 		if (!last_bit)
 			goto err;
 		if (ev->delta.tv_nsec < NEC_HEADER_MARK - 6 * NEC_UNIT)
 			goto err;
 		data->state = STATE_HEADER_SPACE;
 		return 0;
 	case STATE_HEADER_SPACE:
 		if (last_bit)
 			goto err;
 		if (ev->delta.tv_nsec >= NEC_HEADER_SPACE - NEC_UNIT / 2) {
 			data->state = STATE_MARK;
 			return 0;
 		}

 		if (ev->delta.tv_nsec >= NEC_REPEAT_SPACE - NEC_UNIT / 2) {
 			ir_repeat(input_dev);
 			IR_dprintk(1, "Repeat last key\n");
 			data->state = STATE_TRAILER_MARK;
 			return 0;
 		}
 		goto err;
 	case STATE_MARK:
 		if (!last_bit)
 			goto err;
 		if ((ev->delta.tv_nsec > NEC_MARK + NEC_UNIT / 2) ||
 		    (ev->delta.tv_nsec < NEC_MARK - NEC_UNIT / 2))
 			goto err;
 		data->state = STATE_SPACE;
 		return 0;
 	case STATE_SPACE:
 		if (last_bit)
 			goto err;

 		if ((ev->delta.tv_nsec >= NEC_0_SPACE - NEC_UNIT / 2) &&
 		    (ev->delta.tv_nsec < NEC_0_SPACE + NEC_UNIT / 2))
 			bit = 0;
 		else if ((ev->delta.tv_nsec >= NEC_1_SPACE - NEC_UNIT / 2) &&
 		         (ev->delta.tv_nsec < NEC_1_SPACE + NEC_UNIT / 2))
 			bit = 1;
 		else {
 			IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n",
 				data->count,
 				last_bit ? "pulse" : "space",
 				(ev->delta.tv_nsec + 500) / 1000);

 			goto err2;
 		}

 		/* Ok, we've got a valid bit. proccess it */
 		if (bit) {
 			int shift = data->count;

 			/*
 			 * NEC transmit bytes on this temporal order:
 			 * address | not address | command | not command
 			 */
 			if (shift < 8) {
 				data->nec_code.address |= 1 << shift;
 			} else if (shift < 16) {
 				data->nec_code.not_address |= 1 << (shift - 8);
 			} else if (shift < 24) {
 				data->nec_code.command |= 1 << (shift - 16);
 			} else {
 				data->nec_code.not_command |= 1 << (shift - 24);
 			}
 		}
 		if (++data->count == NEC_NBITS) {
 			u32 scancode;
 			/*
 			 * Fixme: may need to accept Extended NEC protocol?
 			 */
 			if ((data->nec_code.command ^ data->nec_code.not_command) != 0xff)
 				goto checksum_err;

 			if ((data->nec_code.address ^ data->nec_code.not_address) != 0xff) {
 				/* Extended NEC */
 				scancode = data->nec_code.address << 16 |
 					   data->nec_code.not_address << 8 |
 					   data->nec_code.command;
 				IR_dprintk(1, "NEC scancode 0x%06x\n", scancode);
 			} else {
 				/* normal NEC */
 				scancode = data->nec_code.address << 8 |
 					   data->nec_code.command;
 				IR_dprintk(1, "NEC scancode 0x%04x\n", scancode);
 			}
 			ir_keydown(input_dev, scancode, 0);

 			data->state = STATE_TRAILER_MARK;
 		} else
 			data->state = STATE_MARK;
 		return 0;
 	case STATE_TRAILER_MARK:
 		if (!last_bit)
 			goto err;
 		data->state = STATE_TRAILER_SPACE;
 		return 0;
 	case STATE_TRAILER_SPACE:
 		if (last_bit)
 			goto err;
 		data->state = STATE_INACTIVE;
 		return 0;
 	}

 err:
 	IR_dprintk(1, "NEC decoded failed at state %d (%s) @ %luus\n",
 		   data->state,
 		   bit ? "pulse" : "space",
 		   (ev->delta.tv_nsec + 500) / 1000);
 err2:
 	data->state = STATE_INACTIVE;
 	return -EINVAL;

 checksum_err:
 	data->state = STATE_INACTIVE;
 	IR_dprintk(1, "NEC checksum error: received 0x%02x%02x%02x%02x\n",
 		   data->nec_code.address,
 		   data->nec_code.not_address,
 		   data->nec_code.command,
 		   data->nec_code.not_command);
 	return -EINVAL;
 }

 static int ir_nec_register(struct input_dev *input_dev)
 {
 	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
 	struct decoder_data *data;
 	int rc;

 	rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
 	if (rc < 0)
 		return rc;

 	data = kzalloc(sizeof(*data), GFP_KERNEL);
 	if (!data) {
 		sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
 		return -ENOMEM;
 	}

 	data->ir_dev = ir_dev;
 	data->enabled = 1;

 	spin_lock(&decoder_lock);
 	list_add_tail(&data->list, &decoder_list);
 	spin_unlock(&decoder_lock);

 	return 0;
 }

 static int ir_nec_unregister(struct input_dev *input_dev)
 {
 	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
 	static struct decoder_data *data;

 	data = get_decoder_data(ir_dev);
 	if (!data)
 		return 0;

 	sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);

 	spin_lock(&decoder_lock);
 	list_del(&data->list);
 	spin_unlock(&decoder_lock);

 	return 0;
 }

 static struct ir_raw_handler nec_handler = {
 	.decode		= ir_nec_decode,
 	.raw_register	= ir_nec_register,
 	.raw_unregister	= ir_nec_unregister,
 };

 static int __init ir_nec_decode_init(void)
 {
 	ir_raw_handler_register(&nec_handler);

 	printk(KERN_INFO "IR NEC protocol handler initialized\n");
 	return 0;
 }

 static void __exit ir_nec_decode_exit(void)
 {
 	ir_raw_handler_unregister(&nec_handler);
 }

 module_init(ir_nec_decode_init);
 module_exit(ir_nec_decode_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
 MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
 MODULE_DESCRIPTION("NEC IR protocol decoder");
	/* ir-nec-decoder.c - handle NEC IR Pulse/Space protocol
	*
	* 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 <media/ir-core.h>

	#define NEC_NBITS 32
	#define NEC_UNIT 559979 /* ns */
	#define NEC_HEADER_MARK (16 * NEC_UNIT)
	#define NEC_HEADER_SPACE (8 * NEC_UNIT)
	#define NEC_REPEAT_SPACE (4 * NEC_UNIT)
	#define NEC_MARK (NEC_UNIT)
	#define NEC_0_SPACE (NEC_UNIT)
	#define NEC_1_SPACE (3 * NEC_UNIT)

	/* Used to register nec_decoder clients */
	static LIST_HEAD(decoder_list);
	static spinlock_t decoder_lock;

	enum nec_state {
	STATE_INACTIVE,
	STATE_HEADER_MARK,
	STATE_HEADER_SPACE,
	STATE_MARK,
	STATE_SPACE,
	STATE_TRAILER_MARK,
	STATE_TRAILER_SPACE,
	};

	struct nec_code {
	u8 address;
	u8 not_address;
	u8 command;
	u8 not_command;
	};

	struct decoder_data {
	struct list_head list;
	struct ir_input_dev *ir_dev;
	int enabled:1;

	/* State machine control */
	enum nec_state state;
	struct nec_code nec_code;
	unsigned count;
	};


	/**
	* get_decoder_data() - gets decoder data
	* @input_dev: input device
	*
	* Returns the struct decoder_data that corresponds to a device
	*/

	static struct decoder_data get_decoder_data(struct ir_input_dev ir_dev)
	{
	struct decoder_data *data = NULL;

	spin_lock(&decoder_lock);
	list_for_each_entry(data, &decoder_list, list) {
	if (data->ir_dev == ir_dev)
	break;
	}
	spin_unlock(&decoder_lock);
	return data;
	}

	static ssize_t store_enabled(struct device *d,
	struct device_attribute *mattr,
	const char *buf,
	size_t len)
	{
	unsigned long value;
	struct ir_input_dev *ir_dev = dev_get_drvdata(d);
	struct decoder_data *data = get_decoder_data(ir_dev);

	if (!data)
	return -EINVAL;

	if (strict_strtoul(buf, 10, &value) \|\| value > 1)
	return -EINVAL;

	data->enabled = value;

	return len;
	}

	static ssize_t show_enabled(struct device *d,
	struct device_attribute mattr, char buf)
	{
	struct ir_input_dev *ir_dev = dev_get_drvdata(d);
	struct decoder_data *data = get_decoder_data(ir_dev);

	if (!data)
	return -EINVAL;

	if (data->enabled)
	return sprintf(buf, "1\n");
	else
	return sprintf(buf, "0\n");
	}

	static DEVICE_ATTR(enabled, S_IRUGO \| S_IWUSR, show_enabled, store_enabled);

	static struct attribute *decoder_attributes[] = {
	&dev_attr_enabled.attr,
	NULL
	};

	static struct attribute_group decoder_attribute_group = {
	.name = "nec_decoder",
	.attrs = decoder_attributes,
	};


	/**
	* ir_nec_decode() - Decode one NEC pulse or space
	* @input_dev: the struct input_dev descriptor of the device
	* @ev: event array with type/duration of pulse/space
	*
	* This function returns -EINVAL if the pulse violates the state machine
	*/
	static int ir_nec_decode(struct input_dev *input_dev,
	struct ir_raw_event *ev)
	{
	struct decoder_data *data;
	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
	int bit, last_bit;

	data = get_decoder_data(ir_dev);
	if (!data)
	return -EINVAL;

	if (!data->enabled)
	return 0;

	/* Except for the initial event, what matters is the previous bit */
	bit = (ev->type & IR_PULSE) ? 1 : 0;

	last_bit = !bit;

	/* Discards spurious space last_bits when inactive */

	/* Very long delays are considered as start events */
	if (ev->delta.tv_nsec > NEC_HEADER_MARK + NEC_HEADER_SPACE - NEC_UNIT / 2)
	data->state = STATE_INACTIVE;

	if (ev->type & IR_START_EVENT)
	data->state = STATE_INACTIVE;

	switch (data->state) {
	case STATE_INACTIVE:
	if (!bit) /* PULSE marks the start event */
	return 0;

	data->count = 0;
	data->state = STATE_HEADER_MARK;
	memset (&data->nec_code, 0, sizeof(data->nec_code));
	return 0;
	case STATE_HEADER_MARK:
	if (!last_bit)
	goto err;
	if (ev->delta.tv_nsec < NEC_HEADER_MARK - 6 * NEC_UNIT)
	goto err;
	data->state = STATE_HEADER_SPACE;
	return 0;
	case STATE_HEADER_SPACE:
	if (last_bit)
	goto err;
	if (ev->delta.tv_nsec >= NEC_HEADER_SPACE - NEC_UNIT / 2) {
	data->state = STATE_MARK;
	return 0;
	}

	if (ev->delta.tv_nsec >= NEC_REPEAT_SPACE - NEC_UNIT / 2) {
	ir_repeat(input_dev);
	IR_dprintk(1, "Repeat last key\n");
	data->state = STATE_TRAILER_MARK;
	return 0;
	}
	goto err;
	case STATE_MARK:
	if (!last_bit)
	goto err;
	if ((ev->delta.tv_nsec > NEC_MARK + NEC_UNIT / 2) \|\|
	(ev->delta.tv_nsec < NEC_MARK - NEC_UNIT / 2))
	goto err;
	data->state = STATE_SPACE;
	return 0;
	case STATE_SPACE:
	if (last_bit)
	goto err;

	if ((ev->delta.tv_nsec >= NEC_0_SPACE - NEC_UNIT / 2) &&
	(ev->delta.tv_nsec < NEC_0_SPACE + NEC_UNIT / 2))
	bit = 0;
	else if ((ev->delta.tv_nsec >= NEC_1_SPACE - NEC_UNIT / 2) &&
	(ev->delta.tv_nsec < NEC_1_SPACE + NEC_UNIT / 2))
	bit = 1;
	else {
	IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n",
	data->count,
	last_bit ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);

	goto err2;
	}

	/* Ok, we've got a valid bit. proccess it */
	if (bit) {
	int shift = data->count;

	/*
	* NEC transmit bytes on this temporal order:
	* address \| not address \| command \| not command
	*/
	if (shift < 8) {
	data->nec_code.address \|= 1 << shift;
	} else if (shift < 16) {
	data->nec_code.not_address \|= 1 << (shift - 8);
	} else if (shift < 24) {
	data->nec_code.command \|= 1 << (shift - 16);
	} else {
	data->nec_code.not_command \|= 1 << (shift - 24);
	}
	}
	if (++data->count == NEC_NBITS) {
	u32 scancode;
	/*
	* Fixme: may need to accept Extended NEC protocol?
	*/
	if ((data->nec_code.command ^ data->nec_code.not_command) != 0xff)
	goto checksum_err;

	if ((data->nec_code.address ^ data->nec_code.not_address) != 0xff) {
	/* Extended NEC */
	scancode = data->nec_code.address << 16 \|
	data->nec_code.not_address << 8 \|
	data->nec_code.command;
	IR_dprintk(1, "NEC scancode 0x%06x\n", scancode);
	} else {
	/* normal NEC */
	scancode = data->nec_code.address << 8 \|
	data->nec_code.command;
	IR_dprintk(1, "NEC scancode 0x%04x\n", scancode);
	}
	ir_keydown(input_dev, scancode, 0);

	data->state = STATE_TRAILER_MARK;
	} else
	data->state = STATE_MARK;
	return 0;
	case STATE_TRAILER_MARK:
	if (!last_bit)
	goto err;
	data->state = STATE_TRAILER_SPACE;
	return 0;
	case STATE_TRAILER_SPACE:
	if (last_bit)
	goto err;
	data->state = STATE_INACTIVE;
	return 0;
	}

	err:
	IR_dprintk(1, "NEC decoded failed at state %d (%s) @ %luus\n",
	data->state,
	bit ? "pulse" : "space",
	(ev->delta.tv_nsec + 500) / 1000);
	err2:
	data->state = STATE_INACTIVE;
	return -EINVAL;

	checksum_err:
	data->state = STATE_INACTIVE;
	IR_dprintk(1, "NEC checksum error: received 0x%02x%02x%02x%02x\n",
	data->nec_code.address,
	data->nec_code.not_address,
	data->nec_code.command,
	data->nec_code.not_command);
	return -EINVAL;
	}

	static int ir_nec_register(struct input_dev *input_dev)
	{
	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
	struct decoder_data *data;
	int rc;

	rc = sysfs_create_group(&ir_dev->dev.kobj, &decoder_attribute_group);
	if (rc < 0)
	return rc;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
	sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);
	return -ENOMEM;
	}

	data->ir_dev = ir_dev;
	data->enabled = 1;

	spin_lock(&decoder_lock);
	list_add_tail(&data->list, &decoder_list);
	spin_unlock(&decoder_lock);

	return 0;
	}

	static int ir_nec_unregister(struct input_dev *input_dev)
	{
	struct ir_input_dev *ir_dev = input_get_drvdata(input_dev);
	static struct decoder_data *data;

	data = get_decoder_data(ir_dev);
	if (!data)
	return 0;

	sysfs_remove_group(&ir_dev->dev.kobj, &decoder_attribute_group);

	spin_lock(&decoder_lock);
	list_del(&data->list);
	spin_unlock(&decoder_lock);

	return 0;
	}

	static struct ir_raw_handler nec_handler = {
	.decode = ir_nec_decode,
	.raw_register = ir_nec_register,
	.raw_unregister = ir_nec_unregister,
	};

	static int __init ir_nec_decode_init(void)
	{
	ir_raw_handler_register(&nec_handler);

	printk(KERN_INFO "IR NEC protocol handler initialized\n");
	return 0;
	}

	static void __exit ir_nec_decode_exit(void)
	{
	ir_raw_handler_unregister(&nec_handler);
	}

	module_init(ir_nec_decode_init);
	module_exit(ir_nec_decode_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>");
	MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)");
	MODULE_DESCRIPTION("NEC IR protocol decoder");