diff options
Diffstat (limited to 'drivers/media/IR/ir-jvc-decoder.c')
| -rw-r--r-- | drivers/media/IR/ir-jvc-decoder.c | 320 |
1 files changed, 320 insertions, 0 deletions
diff --git a/drivers/media/IR/ir-jvc-decoder.c b/drivers/media/IR/ir-jvc-decoder.c new file mode 100644 index 000000000000..0b804944cbb0 --- /dev/null +++ b/drivers/media/IR/ir-jvc-decoder.c @@ -0,0 +1,320 @@ +/* ir-jvc-decoder.c - handle JVC 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 JVC_NBITS 16 /* dev(8) + func(8) */ +#define JVC_UNIT 525000 /* ns */ +#define JVC_HEADER_PULSE (16 * JVC_UNIT) /* lack of header -> repeat */ +#define JVC_HEADER_SPACE (8 * JVC_UNIT) +#define JVC_BIT_PULSE (1 * JVC_UNIT) +#define JVC_BIT_0_SPACE (1 * JVC_UNIT) +#define JVC_BIT_1_SPACE (3 * JVC_UNIT) +#define JVC_TRAILER_PULSE (1 * JVC_UNIT) +#define JVC_TRAILER_SPACE (35 * JVC_UNIT) + +/* Used to register jvc_decoder clients */ +static LIST_HEAD(decoder_list); +DEFINE_SPINLOCK(decoder_lock); + +enum jvc_state { + STATE_INACTIVE, + STATE_HEADER_SPACE, + STATE_BIT_PULSE, + STATE_BIT_SPACE, + STATE_TRAILER_PULSE, + STATE_TRAILER_SPACE, +}; + +struct decoder_data { + struct list_head list; + struct ir_input_dev *ir_dev; + int enabled:1; + + /* State machine control */ + enum jvc_state state; + u16 jvc_bits; + u16 jvc_old_bits; + unsigned count; + bool first; + bool toggle; +}; + + +/** + * 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 = "jvc_decoder", + .attrs = decoder_attributes, +}; + +/** + * ir_jvc_decode() - Decode one JVC pulse or space + * @input_dev: the struct input_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_jvc_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); + + 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, JVC_UNIT, JVC_UNIT / 2)) + goto out; + + IR_dprintk(2, "JVC 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, JVC_HEADER_PULSE, JVC_UNIT / 2)) + break; + + data->count = 0; + data->first = true; + data->toggle = !data->toggle; + data->state = STATE_HEADER_SPACE; + return 0; + + case STATE_HEADER_SPACE: + if (ev.pulse) + break; + + if (!eq_margin(ev.duration, JVC_HEADER_SPACE, JVC_UNIT / 2)) + break; + + data->state = STATE_BIT_PULSE; + return 0; + + case STATE_BIT_PULSE: + if (!ev.pulse) + break; + + if (!eq_margin(ev.duration, JVC_BIT_PULSE, JVC_UNIT / 2)) + break; + + data->state = STATE_BIT_SPACE; + return 0; + + case STATE_BIT_SPACE: + if (ev.pulse) + break; + + data->jvc_bits <<= 1; + if (eq_margin(ev.duration, JVC_BIT_1_SPACE, JVC_UNIT / 2)) { + data->jvc_bits |= 1; + decrease_duration(&ev, JVC_BIT_1_SPACE); + } else if (eq_margin(ev.duration, JVC_BIT_0_SPACE, JVC_UNIT / 2)) + decrease_duration(&ev, JVC_BIT_0_SPACE); + else + break; + data->count++; + + if (data->count == JVC_NBITS) + 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, JVC_TRAILER_PULSE, JVC_UNIT / 2)) + break; + + data->state = STATE_TRAILER_SPACE; + return 0; + + case STATE_TRAILER_SPACE: + if (ev.pulse) + break; + + if (!geq_margin(ev.duration, JVC_TRAILER_SPACE, JVC_UNIT / 2)) + break; + + if (data->first) { + u32 scancode; + scancode = (bitrev8((data->jvc_bits >> 8) & 0xff) << 8) | + (bitrev8((data->jvc_bits >> 0) & 0xff) << 0); + IR_dprintk(1, "JVC scancode 0x%04x\n", scancode); + ir_keydown(input_dev, scancode, data->toggle); + data->first = false; + data->jvc_old_bits = data->jvc_bits; + } else if (data->jvc_bits == data->jvc_old_bits) { + IR_dprintk(1, "JVC repeat\n"); + ir_repeat(input_dev); + } else { + IR_dprintk(1, "JVC invalid repeat msg\n"); + break; + } + + data->count = 0; + data->state = STATE_BIT_PULSE; + return 0; + } + +out: + IR_dprintk(1, "JVC 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_jvc_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_jvc_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 jvc_handler = { + .decode = ir_jvc_decode, + .raw_register = ir_jvc_register, + .raw_unregister = ir_jvc_unregister, +}; + +static int __init ir_jvc_decode_init(void) +{ + ir_raw_handler_register(&jvc_handler); + + printk(KERN_INFO "IR JVC protocol handler initialized\n"); + return 0; +} + +static void __exit ir_jvc_decode_exit(void) +{ + ir_raw_handler_unregister(&jvc_handler); +} + +module_init(ir_jvc_decode_init); +module_exit(ir_jvc_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Härdeman <david@hardeman.nu>"); +MODULE_DESCRIPTION("JVC IR protocol decoder"); |