/* 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");
