diff options
| -rw-r--r-- | drivers/media/IR/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/media/IR/Makefile | 1 | ||||
| -rw-r--r-- | drivers/media/IR/ir-raw-event.c | 1 | ||||
| -rw-r--r-- | drivers/media/IR/ir-rc5-decoder.c | 371 | ||||
| -rw-r--r-- | include/media/ir-core.h | 7 |
5 files changed, 389 insertions, 0 deletions
diff --git a/drivers/media/IR/Kconfig b/drivers/media/IR/Kconfig index 0c557b8cc93..ba81bda3513 100644 --- a/drivers/media/IR/Kconfig +++ b/drivers/media/IR/Kconfig @@ -18,3 +18,12 @@ config IR_NEC_DECODER ---help--- Enable this option if you have IR with NEC protocol, and if the IR is decoded in software + +config IR_RC5_DECODER + tristate "Enable IR raw decoder for RC-5 protocol" + depends on IR_CORE + default y + + ---help--- + Enable this option if you have IR with RC-5 protocol, and + if the IR is decoded in software diff --git a/drivers/media/IR/Makefile b/drivers/media/IR/Makefile index 0e3f912054c..62e12d5c443 100644 --- a/drivers/media/IR/Makefile +++ b/drivers/media/IR/Makefile @@ -6,3 +6,4 @@ obj-y += keymaps/ obj-$(CONFIG_IR_CORE) += ir-core.o obj-$(CONFIG_VIDEO_IR) += ir-common.o obj-$(CONFIG_IR_NEC_DECODER) += ir-nec-decoder.o +obj-$(CONFIG_IR_RC5_DECODER) += ir-rc5-decoder.o diff --git a/drivers/media/IR/ir-raw-event.c b/drivers/media/IR/ir-raw-event.c index 59f20541b03..617e437e2be 100644 --- a/drivers/media/IR/ir-raw-event.c +++ b/drivers/media/IR/ir-raw-event.c @@ -200,6 +200,7 @@ static void init_decoders(struct work_struct *work) /* Load the decoder modules */ load_nec_decode(); + load_rc5_decode(); /* If needed, we may later add some init code. In this case, it is needed to change the CONFIG_MODULE test at ir-core.h diff --git a/drivers/media/IR/ir-rc5-decoder.c b/drivers/media/IR/ir-rc5-decoder.c new file mode 100644 index 00000000000..4b7eafecd84 --- /dev/null +++ b/drivers/media/IR/ir-rc5-decoder.c @@ -0,0 +1,371 @@ +/* ir-rc5-decoder.c - handle RC-5 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. + */ + +/* + * This code only handles 14 bits RC-5 protocols. There are other variants + * that use a different number of bits. This is currently unsupported + */ + +#include <media/ir-core.h> + +#define RC5_NBITS 14 +#define RC5_HALFBIT 888888 /* ns */ +#define RC5_BIT (RC5_HALFBIT * 2) +#define RC5_DURATION (RC5_BIT * RC5_NBITS) + +#define is_rc5_halfbit(nsec) ((ev->delta.tv_nsec >= RC5_HALFBIT / 2) && \ + (ev->delta.tv_nsec < RC5_HALFBIT + RC5_HALFBIT / 2)) + +#define n_half(nsec) ((ev->delta.tv_nsec + RC5_HALFBIT / 2) / RC5_HALFBIT) + +/* Used to register rc5_decoder clients */ +static LIST_HEAD(decoder_list); +static spinlock_t decoder_lock; + +enum rc5_state { + STATE_INACTIVE, + STATE_START2_SPACE, + STATE_START2_MARK, + STATE_MARKSPACE, + STATE_TRAILER_MARK, +}; + +static char *st_name[] = { + "Inactive", + "start2 sapce", + "start2 mark", + "mark", + "space", + "trailer" +}; + +struct rc5_code { + u8 address; + u8 command; +}; + +struct decoder_data { + struct list_head list; + struct ir_input_dev *ir_dev; + int enabled:1; + + /* State machine control */ + enum rc5_state state; + struct rc5_code rc5_code; + unsigned n_half; + 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 = "rc5_decoder", + .attrs = decoder_attributes, +}; + +/** + * handle_event() - Decode one RC-5 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 handle_event(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, n_half; + + data = get_decoder_data(ir_dev); + if (!data) + return -EINVAL; + + /* 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 > RC5_DURATION + RC5_HALFBIT / 2) + data->state = STATE_INACTIVE; + + if (ev->type & IR_START_EVENT) + data->state = STATE_INACTIVE; + + switch (data->state) { + case STATE_INACTIVE: +IR_dprintk(1, "currently inative. Received bit (%s) @%luus\n", + last_bit ? "pulse" : "space", + (ev->delta.tv_nsec + 500) / 1000); + + /* Discards the initial start space */ + if (bit) + return 0; + data->count = 0; + data->n_half = 0; + memset (&data->rc5_code, 0, sizeof(data->rc5_code)); + + data->state = STATE_START2_SPACE; + return 0; + case STATE_START2_SPACE: + if (last_bit) + goto err; + if (!is_rc5_halfbit(ev->delta.tv_nsec)) + goto err; + data->state = STATE_START2_MARK; + return 0; + case STATE_START2_MARK: + if (!last_bit) + goto err; + + if (!is_rc5_halfbit(ev->delta.tv_nsec)) + goto err; + + data->state = STATE_MARKSPACE; + return 0; + case STATE_MARKSPACE: + n_half = n_half(ev->delta.tv_nsec); + if (n_half < 1 || n_half > 3) { + IR_dprintk(1, "Decode failed at %d-th bit (%s) @%luus\n", + data->count, + last_bit ? "pulse" : "space", + (ev->delta.tv_nsec + 500) / 1000); +printk("%d halves\n", n_half); + goto err2; + } + data->n_half += n_half; + + if (!last_bit) + return 0; + + /* Got one complete mark/space cycle */ + + bit = ((data->count + 1) * 2)/ data->n_half; + +printk("%d halves, %d bits\n", n_half, bit); + +#if 1 /* SANITY check - while testing the decoder */ + if (bit > 1) { + IR_dprintk(1, "Decoder HAS failed at %d-th bit (%s) @%luus\n", + data->count, + last_bit ? "pulse" : "space", + (ev->delta.tv_nsec + 500) / 1000); + + goto err2; + } +#endif + /* Ok, we've got a valid bit. proccess it */ + if (bit) { + int shift = data->count; + + /* + * RC-5 transmit bytes on this temporal order: + * address | not address | command | not command + */ + if (shift < 8) { + data->rc5_code.address |= 1 << shift; + } else { + data->rc5_code.command |= 1 << (shift - 8); + } + } + IR_dprintk(1, "RC-5: bit #%d: %d (%d)\n", + data->count, bit, data->n_half); + if (++data->count >= RC5_NBITS) { + u32 scancode; + scancode = data->rc5_code.address << 8 | + data->rc5_code.command; + IR_dprintk(1, "RC-5 scancode 0x%04x\n", scancode); + + ir_keydown(input_dev, scancode, 0); + + data->state = STATE_TRAILER_MARK; + } + return 0; + case STATE_TRAILER_MARK: + if (!last_bit) + goto err; + data->state = STATE_INACTIVE; + return 0; + } + +err: + IR_dprintk(1, "RC-5 decoded failed at state %s (%s) @ %luus\n", + st_name[data->state], + bit ? "pulse" : "space", + (ev->delta.tv_nsec + 500) / 1000); +err2: + data->state = STATE_INACTIVE; + return -EINVAL; +} + +/** + * ir_rc5_decode() - Decodes all RC-5 pulsecodes on a given array + * @input_dev: the struct input_dev descriptor of the device + * @evs: event array with type/duration of pulse/space + * @len: length of the array + * This function returns the number of decoded pulses + */ +static int ir_rc5_decode(struct input_dev *input_dev, + struct ir_raw_event *evs, + int len) +{ + struct ir_input_dev *ir_dev = input_get_drvdata(input_dev); + struct decoder_data *data; + int pos = 0; + int rc = 0; + + data = get_decoder_data(ir_dev); + if (!data || !data->enabled) + return 0; + + for (pos = 0; pos < len; pos++) + handle_event(input_dev, &evs[pos]); + + return rc; +} + +static int ir_rc5_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_rc5_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 rc5_handler = { + .decode = ir_rc5_decode, + .raw_register = ir_rc5_register, + .raw_unregister = ir_rc5_unregister, +}; + +static int __init ir_rc5_decode_init(void) +{ + ir_raw_handler_register(&rc5_handler); + + printk(KERN_INFO "IR RC-5 protocol handler initialized\n"); + return 0; +} + +static void __exit ir_rc5_decode_exit(void) +{ + ir_raw_handler_unregister(&rc5_handler); +} + +module_init(ir_rc5_decode_init); +module_exit(ir_rc5_decode_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@redhat.com>"); +MODULE_AUTHOR("Red Hat Inc. (http://www.redhat.com)"); +MODULE_DESCRIPTION("RC-5 IR protocol decoder"); diff --git a/include/media/ir-core.h b/include/media/ir-core.h index b452a478c12..40900739cb8 100644 --- a/include/media/ir-core.h +++ b/include/media/ir-core.h @@ -178,4 +178,11 @@ void ir_raw_init(void); #define load_nec_decode() 0 #endif +/* from ir-rc5-decoder.c */ +#ifdef CONFIG_IR_RC5_DECODER_MODULE +#define load_rc5_decode() request_module("ir-rc5-decoder") +#else +#define load_rc5_decode() 0 +#endif + #endif /* _IR_CORE */ |