diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/media/rc/rc-ir-raw.c | 717 |
1 files changed, 717 insertions, 0 deletions
diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c new file mode 100644 index 000000000..16e33d7ea --- /dev/null +++ b/drivers/media/rc/rc-ir-raw.c @@ -0,0 +1,717 @@ +// SPDX-License-Identifier: GPL-2.0 +// rc-ir-raw.c - handle IR pulse/space events +// +// Copyright (C) 2010 by Mauro Carvalho Chehab + +#include <linux/export.h> +#include <linux/kthread.h> +#include <linux/mutex.h> +#include <linux/kmod.h> +#include <linux/sched.h> +#include "rc-core-priv.h" + +/* Used to keep track of IR raw clients, protected by ir_raw_handler_lock */ +static LIST_HEAD(ir_raw_client_list); + +/* Used to handle IR raw handler extensions */ +DEFINE_MUTEX(ir_raw_handler_lock); +static LIST_HEAD(ir_raw_handler_list); +static atomic64_t available_protocols = ATOMIC64_INIT(0); + +static int ir_raw_event_thread(void *data) +{ + struct ir_raw_event ev; + struct ir_raw_handler *handler; + struct ir_raw_event_ctrl *raw = data; + struct rc_dev *dev = raw->dev; + + while (1) { + mutex_lock(&ir_raw_handler_lock); + while (kfifo_out(&raw->kfifo, &ev, 1)) { + if (is_timing_event(ev)) { + if (ev.duration == 0) + dev_warn_once(&dev->dev, "nonsensical timing event of duration 0"); + if (is_timing_event(raw->prev_ev) && + !is_transition(&ev, &raw->prev_ev)) + dev_warn_once(&dev->dev, "two consecutive events of type %s", + TO_STR(ev.pulse)); + } + list_for_each_entry(handler, &ir_raw_handler_list, list) + if (dev->enabled_protocols & + handler->protocols || !handler->protocols) + handler->decode(dev, ev); + lirc_raw_event(dev, ev); + raw->prev_ev = ev; + } + mutex_unlock(&ir_raw_handler_lock); + + set_current_state(TASK_INTERRUPTIBLE); + + if (kthread_should_stop()) { + __set_current_state(TASK_RUNNING); + break; + } else if (!kfifo_is_empty(&raw->kfifo)) + set_current_state(TASK_RUNNING); + + schedule(); + } + + return 0; +} + +/** + * ir_raw_event_store() - pass a pulse/space duration to the raw ir decoders + * @dev: the struct rc_dev device descriptor + * @ev: the struct ir_raw_event descriptor of the pulse/space + * + * This routine (which may be called from an interrupt context) stores a + * pulse/space duration for the raw ir decoding state machines. Pulses are + * signalled as positive values and spaces as negative values. A zero value + * will reset the decoding state machines. + */ +int ir_raw_event_store(struct rc_dev *dev, struct ir_raw_event *ev) +{ + if (!dev->raw) + return -EINVAL; + + dev_dbg(&dev->dev, "sample: (%05dus %s)\n", + ev->duration, TO_STR(ev->pulse)); + + if (!kfifo_put(&dev->raw->kfifo, *ev)) { + dev_err(&dev->dev, "IR event FIFO is full!\n"); + return -ENOSPC; + } + + return 0; +} +EXPORT_SYMBOL_GPL(ir_raw_event_store); + +/** + * ir_raw_event_store_edge() - notify raw ir decoders of the start of a pulse/space + * @dev: the struct rc_dev device descriptor + * @pulse: true for pulse, false for space + * + * This routine (which may be called from an interrupt context) is used to + * store the beginning of an ir pulse or space (or the start/end of ir + * reception) for the raw ir decoding state machines. This is used by + * hardware which does not provide durations directly but only interrupts + * (or similar events) on state change. + */ +int ir_raw_event_store_edge(struct rc_dev *dev, bool pulse) +{ + ktime_t now; + struct ir_raw_event ev = {}; + + if (!dev->raw) + return -EINVAL; + + now = ktime_get(); + ev.duration = ktime_to_us(ktime_sub(now, dev->raw->last_event)); + ev.pulse = !pulse; + + return ir_raw_event_store_with_timeout(dev, &ev); +} +EXPORT_SYMBOL_GPL(ir_raw_event_store_edge); + +/* + * ir_raw_event_store_with_timeout() - pass a pulse/space duration to the raw + * ir decoders, schedule decoding and + * timeout + * @dev: the struct rc_dev device descriptor + * @ev: the struct ir_raw_event descriptor of the pulse/space + * + * This routine (which may be called from an interrupt context) stores a + * pulse/space duration for the raw ir decoding state machines, schedules + * decoding and generates a timeout. + */ +int ir_raw_event_store_with_timeout(struct rc_dev *dev, struct ir_raw_event *ev) +{ + ktime_t now; + int rc = 0; + + if (!dev->raw) + return -EINVAL; + + now = ktime_get(); + + spin_lock(&dev->raw->edge_spinlock); + rc = ir_raw_event_store(dev, ev); + + dev->raw->last_event = now; + + /* timer could be set to timeout (125ms by default) */ + if (!timer_pending(&dev->raw->edge_handle) || + time_after(dev->raw->edge_handle.expires, + jiffies + msecs_to_jiffies(15))) { + mod_timer(&dev->raw->edge_handle, + jiffies + msecs_to_jiffies(15)); + } + spin_unlock(&dev->raw->edge_spinlock); + + return rc; +} +EXPORT_SYMBOL_GPL(ir_raw_event_store_with_timeout); + +/** + * ir_raw_event_store_with_filter() - pass next pulse/space to decoders with some processing + * @dev: the struct rc_dev device descriptor + * @ev: the event that has occurred + * + * This routine (which may be called from an interrupt context) works + * in similar manner to ir_raw_event_store_edge. + * This routine is intended for devices with limited internal buffer + * It automerges samples of same type, and handles timeouts. Returns non-zero + * if the event was added, and zero if the event was ignored due to idle + * processing. + */ +int ir_raw_event_store_with_filter(struct rc_dev *dev, struct ir_raw_event *ev) +{ + if (!dev->raw) + return -EINVAL; + + /* Ignore spaces in idle mode */ + if (dev->idle && !ev->pulse) + return 0; + else if (dev->idle) + ir_raw_event_set_idle(dev, false); + + if (!dev->raw->this_ev.duration) + dev->raw->this_ev = *ev; + else if (ev->pulse == dev->raw->this_ev.pulse) + dev->raw->this_ev.duration += ev->duration; + else { + ir_raw_event_store(dev, &dev->raw->this_ev); + dev->raw->this_ev = *ev; + } + + /* Enter idle mode if necessary */ + if (!ev->pulse && dev->timeout && + dev->raw->this_ev.duration >= dev->timeout) + ir_raw_event_set_idle(dev, true); + + return 1; +} +EXPORT_SYMBOL_GPL(ir_raw_event_store_with_filter); + +/** + * ir_raw_event_set_idle() - provide hint to rc-core when the device is idle or not + * @dev: the struct rc_dev device descriptor + * @idle: whether the device is idle or not + */ +void ir_raw_event_set_idle(struct rc_dev *dev, bool idle) +{ + if (!dev->raw) + return; + + dev_dbg(&dev->dev, "%s idle mode\n", idle ? "enter" : "leave"); + + if (idle) { + dev->raw->this_ev.timeout = true; + ir_raw_event_store(dev, &dev->raw->this_ev); + dev->raw->this_ev = (struct ir_raw_event) {}; + } + + if (dev->s_idle) + dev->s_idle(dev, idle); + + dev->idle = idle; +} +EXPORT_SYMBOL_GPL(ir_raw_event_set_idle); + +/** + * ir_raw_event_handle() - schedules the decoding of stored ir data + * @dev: the struct rc_dev device descriptor + * + * This routine will tell rc-core to start decoding stored ir data. + */ +void ir_raw_event_handle(struct rc_dev *dev) +{ + if (!dev->raw || !dev->raw->thread) + return; + + wake_up_process(dev->raw->thread); +} +EXPORT_SYMBOL_GPL(ir_raw_event_handle); + +/* used internally by the sysfs interface */ +u64 +ir_raw_get_allowed_protocols(void) +{ + return atomic64_read(&available_protocols); +} + +static int change_protocol(struct rc_dev *dev, u64 *rc_proto) +{ + struct ir_raw_handler *handler; + u32 timeout = 0; + + mutex_lock(&ir_raw_handler_lock); + list_for_each_entry(handler, &ir_raw_handler_list, list) { + if (!(dev->enabled_protocols & handler->protocols) && + (*rc_proto & handler->protocols) && handler->raw_register) + handler->raw_register(dev); + + if ((dev->enabled_protocols & handler->protocols) && + !(*rc_proto & handler->protocols) && + handler->raw_unregister) + handler->raw_unregister(dev); + } + mutex_unlock(&ir_raw_handler_lock); + + if (!dev->max_timeout) + return 0; + + mutex_lock(&ir_raw_handler_lock); + list_for_each_entry(handler, &ir_raw_handler_list, list) { + if (handler->protocols & *rc_proto) { + if (timeout < handler->min_timeout) + timeout = handler->min_timeout; + } + } + mutex_unlock(&ir_raw_handler_lock); + + if (timeout == 0) + timeout = IR_DEFAULT_TIMEOUT; + else + timeout += MS_TO_US(10); + + if (timeout < dev->min_timeout) + timeout = dev->min_timeout; + else if (timeout > dev->max_timeout) + timeout = dev->max_timeout; + + if (dev->s_timeout) + dev->s_timeout(dev, timeout); + else + dev->timeout = timeout; + + return 0; +} + +static void ir_raw_disable_protocols(struct rc_dev *dev, u64 protocols) +{ + mutex_lock(&dev->lock); + dev->enabled_protocols &= ~protocols; + mutex_unlock(&dev->lock); +} + +/** + * ir_raw_gen_manchester() - Encode data with Manchester (bi-phase) modulation. + * @ev: Pointer to pointer to next free event. *@ev is incremented for + * each raw event filled. + * @max: Maximum number of raw events to fill. + * @timings: Manchester modulation timings. + * @n: Number of bits of data. + * @data: Data bits to encode. + * + * Encodes the @n least significant bits of @data using Manchester (bi-phase) + * modulation with the timing characteristics described by @timings, writing up + * to @max raw IR events using the *@ev pointer. + * + * Returns: 0 on success. + * -ENOBUFS if there isn't enough space in the array to fit the + * full encoded data. In this case all @max events will have been + * written. + */ +int ir_raw_gen_manchester(struct ir_raw_event **ev, unsigned int max, + const struct ir_raw_timings_manchester *timings, + unsigned int n, u64 data) +{ + bool need_pulse; + u64 i; + int ret = -ENOBUFS; + + i = BIT_ULL(n - 1); + + if (timings->leader_pulse) { + if (!max--) + return ret; + init_ir_raw_event_duration((*ev), 1, timings->leader_pulse); + if (timings->leader_space) { + if (!max--) + return ret; + init_ir_raw_event_duration(++(*ev), 0, + timings->leader_space); + } + } else { + /* continue existing signal */ + --(*ev); + } + /* from here on *ev will point to the last event rather than the next */ + + while (n && i > 0) { + need_pulse = !(data & i); + if (timings->invert) + need_pulse = !need_pulse; + if (need_pulse == !!(*ev)->pulse) { + (*ev)->duration += timings->clock; + } else { + if (!max--) + goto nobufs; + init_ir_raw_event_duration(++(*ev), need_pulse, + timings->clock); + } + + if (!max--) + goto nobufs; + init_ir_raw_event_duration(++(*ev), !need_pulse, + timings->clock); + i >>= 1; + } + + if (timings->trailer_space) { + if (!(*ev)->pulse) + (*ev)->duration += timings->trailer_space; + else if (!max--) + goto nobufs; + else + init_ir_raw_event_duration(++(*ev), 0, + timings->trailer_space); + } + + ret = 0; +nobufs: + /* point to the next event rather than last event before returning */ + ++(*ev); + return ret; +} +EXPORT_SYMBOL(ir_raw_gen_manchester); + +/** + * ir_raw_gen_pd() - Encode data to raw events with pulse-distance modulation. + * @ev: Pointer to pointer to next free event. *@ev is incremented for + * each raw event filled. + * @max: Maximum number of raw events to fill. + * @timings: Pulse distance modulation timings. + * @n: Number of bits of data. + * @data: Data bits to encode. + * + * Encodes the @n least significant bits of @data using pulse-distance + * modulation with the timing characteristics described by @timings, writing up + * to @max raw IR events using the *@ev pointer. + * + * Returns: 0 on success. + * -ENOBUFS if there isn't enough space in the array to fit the + * full encoded data. In this case all @max events will have been + * written. + */ +int ir_raw_gen_pd(struct ir_raw_event **ev, unsigned int max, + const struct ir_raw_timings_pd *timings, + unsigned int n, u64 data) +{ + int i; + int ret; + unsigned int space; + + if (timings->header_pulse) { + ret = ir_raw_gen_pulse_space(ev, &max, timings->header_pulse, + timings->header_space); + if (ret) + return ret; + } + + if (timings->msb_first) { + for (i = n - 1; i >= 0; --i) { + space = timings->bit_space[(data >> i) & 1]; + ret = ir_raw_gen_pulse_space(ev, &max, + timings->bit_pulse, + space); + if (ret) + return ret; + } + } else { + for (i = 0; i < n; ++i, data >>= 1) { + space = timings->bit_space[data & 1]; + ret = ir_raw_gen_pulse_space(ev, &max, + timings->bit_pulse, + space); + if (ret) + return ret; + } + } + + ret = ir_raw_gen_pulse_space(ev, &max, timings->trailer_pulse, + timings->trailer_space); + return ret; +} +EXPORT_SYMBOL(ir_raw_gen_pd); + +/** + * ir_raw_gen_pl() - Encode data to raw events with pulse-length modulation. + * @ev: Pointer to pointer to next free event. *@ev is incremented for + * each raw event filled. + * @max: Maximum number of raw events to fill. + * @timings: Pulse distance modulation timings. + * @n: Number of bits of data. + * @data: Data bits to encode. + * + * Encodes the @n least significant bits of @data using space-distance + * modulation with the timing characteristics described by @timings, writing up + * to @max raw IR events using the *@ev pointer. + * + * Returns: 0 on success. + * -ENOBUFS if there isn't enough space in the array to fit the + * full encoded data. In this case all @max events will have been + * written. + */ +int ir_raw_gen_pl(struct ir_raw_event **ev, unsigned int max, + const struct ir_raw_timings_pl *timings, + unsigned int n, u64 data) +{ + int i; + int ret = -ENOBUFS; + unsigned int pulse; + + if (!max--) + return ret; + + init_ir_raw_event_duration((*ev)++, 1, timings->header_pulse); + + if (timings->msb_first) { + for (i = n - 1; i >= 0; --i) { + if (!max--) + return ret; + init_ir_raw_event_duration((*ev)++, 0, + timings->bit_space); + if (!max--) + return ret; + pulse = timings->bit_pulse[(data >> i) & 1]; + init_ir_raw_event_duration((*ev)++, 1, pulse); + } + } else { + for (i = 0; i < n; ++i, data >>= 1) { + if (!max--) + return ret; + init_ir_raw_event_duration((*ev)++, 0, + timings->bit_space); + if (!max--) + return ret; + pulse = timings->bit_pulse[data & 1]; + init_ir_raw_event_duration((*ev)++, 1, pulse); + } + } + + if (!max--) + return ret; + + init_ir_raw_event_duration((*ev)++, 0, timings->trailer_space); + + return 0; +} +EXPORT_SYMBOL(ir_raw_gen_pl); + +/** + * ir_raw_encode_scancode() - Encode a scancode as raw events + * + * @protocol: protocol + * @scancode: scancode filter describing a single scancode + * @events: array of raw events to write into + * @max: max number of raw events + * + * Attempts to encode the scancode as raw events. + * + * Returns: The number of events written. + * -ENOBUFS if there isn't enough space in the array to fit the + * encoding. In this case all @max events will have been written. + * -EINVAL if the scancode is ambiguous or invalid, or if no + * compatible encoder was found. + */ +int ir_raw_encode_scancode(enum rc_proto protocol, u32 scancode, + struct ir_raw_event *events, unsigned int max) +{ + struct ir_raw_handler *handler; + int ret = -EINVAL; + u64 mask = 1ULL << protocol; + + ir_raw_load_modules(&mask); + + mutex_lock(&ir_raw_handler_lock); + list_for_each_entry(handler, &ir_raw_handler_list, list) { + if (handler->protocols & mask && handler->encode) { + ret = handler->encode(protocol, scancode, events, max); + if (ret >= 0 || ret == -ENOBUFS) + break; + } + } + mutex_unlock(&ir_raw_handler_lock); + + return ret; +} +EXPORT_SYMBOL(ir_raw_encode_scancode); + +/** + * ir_raw_edge_handle() - Handle ir_raw_event_store_edge() processing + * + * @t: timer_list + * + * This callback is armed by ir_raw_event_store_edge(). It does two things: + * first of all, rather than calling ir_raw_event_handle() for each + * edge and waking up the rc thread, 15 ms after the first edge + * ir_raw_event_handle() is called. Secondly, generate a timeout event + * no more IR is received after the rc_dev timeout. + */ +static void ir_raw_edge_handle(struct timer_list *t) +{ + struct ir_raw_event_ctrl *raw = from_timer(raw, t, edge_handle); + struct rc_dev *dev = raw->dev; + unsigned long flags; + ktime_t interval; + + spin_lock_irqsave(&dev->raw->edge_spinlock, flags); + interval = ktime_sub(ktime_get(), dev->raw->last_event); + if (ktime_to_us(interval) >= dev->timeout) { + struct ir_raw_event ev = { + .timeout = true, + .duration = ktime_to_us(interval) + }; + + ir_raw_event_store(dev, &ev); + } else { + mod_timer(&dev->raw->edge_handle, + jiffies + usecs_to_jiffies(dev->timeout - + ktime_to_us(interval))); + } + spin_unlock_irqrestore(&dev->raw->edge_spinlock, flags); + + ir_raw_event_handle(dev); +} + +/** + * ir_raw_encode_carrier() - Get carrier used for protocol + * + * @protocol: protocol + * + * Attempts to find the carrier for the specified protocol + * + * Returns: The carrier in Hz + * -EINVAL if the protocol is invalid, or if no + * compatible encoder was found. + */ +int ir_raw_encode_carrier(enum rc_proto protocol) +{ + struct ir_raw_handler *handler; + int ret = -EINVAL; + u64 mask = BIT_ULL(protocol); + + mutex_lock(&ir_raw_handler_lock); + list_for_each_entry(handler, &ir_raw_handler_list, list) { + if (handler->protocols & mask && handler->encode) { + ret = handler->carrier; + break; + } + } + mutex_unlock(&ir_raw_handler_lock); + + return ret; +} +EXPORT_SYMBOL(ir_raw_encode_carrier); + +/* + * Used to (un)register raw event clients + */ +int ir_raw_event_prepare(struct rc_dev *dev) +{ + if (!dev) + return -EINVAL; + + dev->raw = kzalloc(sizeof(*dev->raw), GFP_KERNEL); + if (!dev->raw) + return -ENOMEM; + + dev->raw->dev = dev; + dev->change_protocol = change_protocol; + dev->idle = true; + spin_lock_init(&dev->raw->edge_spinlock); + timer_setup(&dev->raw->edge_handle, ir_raw_edge_handle, 0); + INIT_KFIFO(dev->raw->kfifo); + + return 0; +} + +int ir_raw_event_register(struct rc_dev *dev) +{ + struct task_struct *thread; + + thread = kthread_run(ir_raw_event_thread, dev->raw, "rc%u", dev->minor); + if (IS_ERR(thread)) + return PTR_ERR(thread); + + dev->raw->thread = thread; + + mutex_lock(&ir_raw_handler_lock); + list_add_tail(&dev->raw->list, &ir_raw_client_list); + mutex_unlock(&ir_raw_handler_lock); + + return 0; +} + +void ir_raw_event_free(struct rc_dev *dev) +{ + if (!dev) + return; + + kfree(dev->raw); + dev->raw = NULL; +} + +void ir_raw_event_unregister(struct rc_dev *dev) +{ + struct ir_raw_handler *handler; + + if (!dev || !dev->raw) + return; + + kthread_stop(dev->raw->thread); + del_timer_sync(&dev->raw->edge_handle); + + mutex_lock(&ir_raw_handler_lock); + list_del(&dev->raw->list); + list_for_each_entry(handler, &ir_raw_handler_list, list) + if (handler->raw_unregister && + (handler->protocols & dev->enabled_protocols)) + handler->raw_unregister(dev); + + lirc_bpf_free(dev); + + ir_raw_event_free(dev); + + /* + * A user can be calling bpf(BPF_PROG_{QUERY|ATTACH|DETACH}), so + * ensure that the raw member is null on unlock; this is how + * "device gone" is checked. + */ + mutex_unlock(&ir_raw_handler_lock); +} + +/* + * Extension interface - used to register the IR decoders + */ + +int ir_raw_handler_register(struct ir_raw_handler *ir_raw_handler) +{ + mutex_lock(&ir_raw_handler_lock); + list_add_tail(&ir_raw_handler->list, &ir_raw_handler_list); + atomic64_or(ir_raw_handler->protocols, &available_protocols); + mutex_unlock(&ir_raw_handler_lock); + + return 0; +} +EXPORT_SYMBOL(ir_raw_handler_register); + +void ir_raw_handler_unregister(struct ir_raw_handler *ir_raw_handler) +{ + struct ir_raw_event_ctrl *raw; + u64 protocols = ir_raw_handler->protocols; + + mutex_lock(&ir_raw_handler_lock); + list_del(&ir_raw_handler->list); + list_for_each_entry(raw, &ir_raw_client_list, list) { + if (ir_raw_handler->raw_unregister && + (raw->dev->enabled_protocols & protocols)) + ir_raw_handler->raw_unregister(raw->dev); + ir_raw_disable_protocols(raw->dev, protocols); + } + atomic64_andnot(protocols, &available_protocols); + mutex_unlock(&ir_raw_handler_lock); +} +EXPORT_SYMBOL(ir_raw_handler_unregister); |