drivers/media/IR/ir-sony-decoder.c - kernel/skids - Git at Google

 /* ir-sony-decoder.c - handle Sony IR Pulse/Space protocol
  *
  * Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
  *
  * 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 "ir-core-priv.h"

 #define SONY_UNIT		600000 /* ns */
 #define SONY_HEADER_PULSE	(4 * SONY_UNIT)
 #define	SONY_HEADER_SPACE	(1 * SONY_UNIT)
 #define SONY_BIT_0_PULSE	(1 * SONY_UNIT)
 #define SONY_BIT_1_PULSE	(2 * SONY_UNIT)
 #define SONY_BIT_SPACE		(1 * SONY_UNIT)
 #define SONY_TRAILER_SPACE	(10 * SONY_UNIT) /* minimum */

 /* Used to register sony_decoder clients */
 static LIST_HEAD(decoder_list);
 static DEFINE_SPINLOCK(decoder_lock);

 enum sony_state {
 	STATE_INACTIVE,
 	STATE_HEADER_SPACE,
 	STATE_BIT_PULSE,
 	STATE_BIT_SPACE,
 	STATE_FINISHED,
 };

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

 	/* State machine control */
 	enum sony_state		state;
 	u32			sony_bits;
 	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	= "sony_decoder",
 	.attrs	= decoder_attributes,
 };

 /**
  * ir_sony_decode() - Decode one Sony pulse or space
  * @input_dev:	the struct input_dev descriptor of the device
  * @ev:         the struct ir_raw_event descriptor of the pulse/space
  *
  * This function returns -EINVAL if the pulse violates the state machine
  */
 static int ir_sony_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);
 	u32 scancode;
 	u8 device, subdevice, function;

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

 	if (!data->enabled)
 		return 0;

 	if (IS_RESET(ev)) {
 		data->state = STATE_INACTIVE;
 		return 0;
 	}

 	if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2))
 		goto out;

 	IR_dprintk(2, "Sony 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, SONY_HEADER_PULSE, SONY_UNIT / 2))
 			break;

 		data->count = 0;
 		data->state = STATE_HEADER_SPACE;
 		return 0;

 	case STATE_HEADER_SPACE:
 		if (ev.pulse)
 			break;

 		if (!eq_margin(ev.duration, SONY_HEADER_SPACE, SONY_UNIT / 2))
 			break;

 		data->state = STATE_BIT_PULSE;
 		return 0;

 	case STATE_BIT_PULSE:
 		if (!ev.pulse)
 			break;

 		data->sony_bits <<= 1;
 		if (eq_margin(ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2))
 			data->sony_bits |= 1;
 		else if (!eq_margin(ev.duration, SONY_BIT_0_PULSE, SONY_UNIT / 2))
 			break;

 		data->count++;
 		data->state = STATE_BIT_SPACE;
 		return 0;

 	case STATE_BIT_SPACE:
 		if (ev.pulse)
 			break;

 		if (!geq_margin(ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2))
 			break;

 		decrease_duration(&ev, SONY_BIT_SPACE);

 		if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) {
 			data->state = STATE_BIT_PULSE;
 			return 0;
 		}

 		data->state = STATE_FINISHED;
 		/* Fall through */

 	case STATE_FINISHED:
 		if (ev.pulse)
 			break;

 		if (!geq_margin(ev.duration, SONY_TRAILER_SPACE, SONY_UNIT / 2))
 			break;

 		switch (data->count) {
 		case 12:
 			device    = bitrev8((data->sony_bits <<  3) & 0xF8);
 			subdevice = 0;
 			function  = bitrev8((data->sony_bits >>  4) & 0xFE);
 			break;
 		case 15:
 			device    = bitrev8((data->sony_bits >>  0) & 0xFF);
 			subdevice = 0;
 			function  = bitrev8((data->sony_bits >>  7) & 0xFD);
 			break;
 		case 20:
 			device    = bitrev8((data->sony_bits >>  5) & 0xF8);
 			subdevice = bitrev8((data->sony_bits >>  0) & 0xFF);
 			function  = bitrev8((data->sony_bits >> 12) & 0xFE);
 			break;
 		default:
 			IR_dprintk(1, "Sony invalid bitcount %u\n", data->count);
 			goto out;
 		}

 		scancode = device << 16 | subdevice << 8 | function;
 		IR_dprintk(1, "Sony(%u) scancode 0x%05x\n", data->count, scancode);
 		ir_keydown(input_dev, scancode, 0);
 		data->state = STATE_INACTIVE;
 		return 0;
 	}

 out:
 	IR_dprintk(1, "Sony decode failed at state %d (%uus %s)\n",
 		   data->state, TO_US(ev.duration), TO_STR(ev.pulse));
 	data->state = STATE_INACTIVE;
 	return -EINVAL;
 }

 static int ir_sony_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_sony_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 sony_handler = {
 	.decode		= ir_sony_decode,
 	.raw_register	= ir_sony_register,
 	.raw_unregister	= ir_sony_unregister,
 };

 static int __init ir_sony_decode_init(void)
 {
 	ir_raw_handler_register(&sony_handler);

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

 static void __exit ir_sony_decode_exit(void)
 {
 	ir_raw_handler_unregister(&sony_handler);
 }

 module_init(ir_sony_decode_init);
 module_exit(ir_sony_decode_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
 MODULE_DESCRIPTION("Sony IR protocol decoder");
	/* ir-sony-decoder.c - handle Sony IR Pulse/Space protocol
	*
	* Copyright (C) 2010 by David Härdeman <david@hardeman.nu>
	*
	* 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 "ir-core-priv.h"

	#define SONY_UNIT 600000 /* ns */
	#define SONY_HEADER_PULSE (4 * SONY_UNIT)
	#define SONY_HEADER_SPACE (1 * SONY_UNIT)
	#define SONY_BIT_0_PULSE (1 * SONY_UNIT)
	#define SONY_BIT_1_PULSE (2 * SONY_UNIT)
	#define SONY_BIT_SPACE (1 * SONY_UNIT)
	#define SONY_TRAILER_SPACE (10 * SONY_UNIT) /* minimum */

	/* Used to register sony_decoder clients */
	static LIST_HEAD(decoder_list);
	static DEFINE_SPINLOCK(decoder_lock);

	enum sony_state {
	STATE_INACTIVE,
	STATE_HEADER_SPACE,
	STATE_BIT_PULSE,
	STATE_BIT_SPACE,
	STATE_FINISHED,
	};

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

	/* State machine control */
	enum sony_state state;
	u32 sony_bits;
	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 = "sony_decoder",
	.attrs = decoder_attributes,
	};

	/**
	* ir_sony_decode() - Decode one Sony pulse or space
	* @input_dev: the struct input_dev descriptor of the device
	* @ev: the struct ir_raw_event descriptor of the pulse/space
	*
	* This function returns -EINVAL if the pulse violates the state machine
	*/
	static int ir_sony_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);
	u32 scancode;
	u8 device, subdevice, function;

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

	if (!data->enabled)
	return 0;

	if (IS_RESET(ev)) {
	data->state = STATE_INACTIVE;
	return 0;
	}

	if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2))
	goto out;

	IR_dprintk(2, "Sony 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, SONY_HEADER_PULSE, SONY_UNIT / 2))
	break;

	data->count = 0;
	data->state = STATE_HEADER_SPACE;
	return 0;

	case STATE_HEADER_SPACE:
	if (ev.pulse)
	break;

	if (!eq_margin(ev.duration, SONY_HEADER_SPACE, SONY_UNIT / 2))
	break;

	data->state = STATE_BIT_PULSE;
	return 0;

	case STATE_BIT_PULSE:
	if (!ev.pulse)
	break;

	data->sony_bits <<= 1;
	if (eq_margin(ev.duration, SONY_BIT_1_PULSE, SONY_UNIT / 2))
	data->sony_bits \|= 1;
	else if (!eq_margin(ev.duration, SONY_BIT_0_PULSE, SONY_UNIT / 2))
	break;

	data->count++;
	data->state = STATE_BIT_SPACE;
	return 0;

	case STATE_BIT_SPACE:
	if (ev.pulse)
	break;

	if (!geq_margin(ev.duration, SONY_BIT_SPACE, SONY_UNIT / 2))
	break;

	decrease_duration(&ev, SONY_BIT_SPACE);

	if (!geq_margin(ev.duration, SONY_UNIT, SONY_UNIT / 2)) {
	data->state = STATE_BIT_PULSE;
	return 0;
	}

	data->state = STATE_FINISHED;
	/* Fall through */

	case STATE_FINISHED:
	if (ev.pulse)
	break;

	if (!geq_margin(ev.duration, SONY_TRAILER_SPACE, SONY_UNIT / 2))
	break;

	switch (data->count) {
	case 12:
	device = bitrev8((data->sony_bits << 3) & 0xF8);
	subdevice = 0;
	function = bitrev8((data->sony_bits >> 4) & 0xFE);
	break;
	case 15:
	device = bitrev8((data->sony_bits >> 0) & 0xFF);
	subdevice = 0;
	function = bitrev8((data->sony_bits >> 7) & 0xFD);
	break;
	case 20:
	device = bitrev8((data->sony_bits >> 5) & 0xF8);
	subdevice = bitrev8((data->sony_bits >> 0) & 0xFF);
	function = bitrev8((data->sony_bits >> 12) & 0xFE);
	break;
	default:
	IR_dprintk(1, "Sony invalid bitcount %u\n", data->count);
	goto out;
	}

	scancode = device << 16 \| subdevice << 8 \| function;
	IR_dprintk(1, "Sony(%u) scancode 0x%05x\n", data->count, scancode);
	ir_keydown(input_dev, scancode, 0);
	data->state = STATE_INACTIVE;
	return 0;
	}

	out:
	IR_dprintk(1, "Sony decode failed at state %d (%uus %s)\n",
	data->state, TO_US(ev.duration), TO_STR(ev.pulse));
	data->state = STATE_INACTIVE;
	return -EINVAL;
	}

	static int ir_sony_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_sony_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 sony_handler = {
	.decode = ir_sony_decode,
	.raw_register = ir_sony_register,
	.raw_unregister = ir_sony_unregister,
	};

	static int __init ir_sony_decode_init(void)
	{
	ir_raw_handler_register(&sony_handler);

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

	static void __exit ir_sony_decode_exit(void)
	{
	ir_raw_handler_unregister(&sony_handler);
	}

	module_init(ir_sony_decode_init);
	module_exit(ir_sony_decode_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("David Härdeman <david@hardeman.nu>");
	MODULE_DESCRIPTION("Sony IR protocol decoder");