diff options
Diffstat (limited to 'drivers/media/rc/lirc_dev.c')
| -rw-r--r-- | drivers/media/rc/lirc_dev.c | 852 |
1 files changed, 852 insertions, 0 deletions
diff --git a/drivers/media/rc/lirc_dev.c b/drivers/media/rc/lirc_dev.c new file mode 100644 index 000000000..9c888047f --- /dev/null +++ b/drivers/media/rc/lirc_dev.c @@ -0,0 +1,852 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * LIRC base driver + * + * by Artur Lipowski <alipowski@interia.pl> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/device.h> +#include <linux/file.h> +#include <linux/idr.h> +#include <linux/poll.h> +#include <linux/sched.h> +#include <linux/wait.h> + +#include "rc-core-priv.h" +#include <uapi/linux/lirc.h> + +#define LIRCBUF_SIZE 1024 + +static dev_t lirc_base_dev; + +/* Used to keep track of allocated lirc devices */ +static DEFINE_IDA(lirc_ida); + +/* Only used for sysfs but defined to void otherwise */ +static struct class *lirc_class; + +/** + * lirc_raw_event() - Send raw IR data to lirc to be relayed to userspace + * + * @dev: the struct rc_dev descriptor of the device + * @ev: the struct ir_raw_event descriptor of the pulse/space + */ +void lirc_raw_event(struct rc_dev *dev, struct ir_raw_event ev) +{ + unsigned long flags; + struct lirc_fh *fh; + int sample; + + /* Packet start */ + if (ev.reset) { + /* + * Userspace expects a long space event before the start of + * the signal to use as a sync. This may be done with repeat + * packets and normal samples. But if a reset has been sent + * then we assume that a long time has passed, so we send a + * space with the maximum time value. + */ + sample = LIRC_SPACE(LIRC_VALUE_MASK); + dev_dbg(&dev->dev, "delivering reset sync space to lirc_dev\n"); + + /* Carrier reports */ + } else if (ev.carrier_report) { + sample = LIRC_FREQUENCY(ev.carrier); + dev_dbg(&dev->dev, "carrier report (freq: %d)\n", sample); + + /* Packet end */ + } else if (ev.timeout) { + if (dev->gap) + return; + + dev->gap_start = ktime_get(); + dev->gap = true; + dev->gap_duration = ev.duration; + + sample = LIRC_TIMEOUT(ev.duration); + dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample); + + /* Normal sample */ + } else { + if (dev->gap) { + dev->gap_duration += ktime_to_us(ktime_sub(ktime_get(), + dev->gap_start)); + + /* Cap by LIRC_VALUE_MASK */ + dev->gap_duration = min_t(u64, dev->gap_duration, + LIRC_VALUE_MASK); + + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_for_each_entry(fh, &dev->lirc_fh, list) + kfifo_put(&fh->rawir, + LIRC_SPACE(dev->gap_duration)); + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); + dev->gap = false; + } + + sample = ev.pulse ? LIRC_PULSE(ev.duration) : + LIRC_SPACE(ev.duration); + dev_dbg(&dev->dev, "delivering %uus %s to lirc_dev\n", + ev.duration, TO_STR(ev.pulse)); + } + + /* + * bpf does not care about the gap generated above; that exists + * for backwards compatibility + */ + lirc_bpf_run(dev, sample); + + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_for_each_entry(fh, &dev->lirc_fh, list) { + if (LIRC_IS_TIMEOUT(sample) && !fh->send_timeout_reports) + continue; + if (kfifo_put(&fh->rawir, sample)) + wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM); + } + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); +} + +/** + * lirc_scancode_event() - Send scancode data to lirc to be relayed to + * userspace. This can be called in atomic context. + * @dev: the struct rc_dev descriptor of the device + * @lsc: the struct lirc_scancode describing the decoded scancode + */ +void lirc_scancode_event(struct rc_dev *dev, struct lirc_scancode *lsc) +{ + unsigned long flags; + struct lirc_fh *fh; + + lsc->timestamp = ktime_get_ns(); + + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_for_each_entry(fh, &dev->lirc_fh, list) { + if (kfifo_put(&fh->scancodes, *lsc)) + wake_up_poll(&fh->wait_poll, EPOLLIN | EPOLLRDNORM); + } + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); +} +EXPORT_SYMBOL_GPL(lirc_scancode_event); + +static int lirc_open(struct inode *inode, struct file *file) +{ + struct rc_dev *dev = container_of(inode->i_cdev, struct rc_dev, + lirc_cdev); + struct lirc_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL); + unsigned long flags; + int retval; + + if (!fh) + return -ENOMEM; + + get_device(&dev->dev); + + if (!dev->registered) { + retval = -ENODEV; + goto out_fh; + } + + if (dev->driver_type == RC_DRIVER_IR_RAW) { + if (kfifo_alloc(&fh->rawir, MAX_IR_EVENT_SIZE, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_fh; + } + } + + if (dev->driver_type != RC_DRIVER_IR_RAW_TX) { + if (kfifo_alloc(&fh->scancodes, 32, GFP_KERNEL)) { + retval = -ENOMEM; + goto out_rawir; + } + } + + fh->send_mode = LIRC_MODE_PULSE; + fh->rc = dev; + fh->send_timeout_reports = true; + + if (dev->driver_type == RC_DRIVER_SCANCODE) + fh->rec_mode = LIRC_MODE_SCANCODE; + else + fh->rec_mode = LIRC_MODE_MODE2; + + retval = rc_open(dev); + if (retval) + goto out_kfifo; + + init_waitqueue_head(&fh->wait_poll); + + file->private_data = fh; + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_add(&fh->list, &dev->lirc_fh); + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); + + stream_open(inode, file); + + return 0; +out_kfifo: + if (dev->driver_type != RC_DRIVER_IR_RAW_TX) + kfifo_free(&fh->scancodes); +out_rawir: + if (dev->driver_type == RC_DRIVER_IR_RAW) + kfifo_free(&fh->rawir); +out_fh: + kfree(fh); + put_device(&dev->dev); + + return retval; +} + +static int lirc_close(struct inode *inode, struct file *file) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *dev = fh->rc; + unsigned long flags; + + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_del(&fh->list); + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); + + if (dev->driver_type == RC_DRIVER_IR_RAW) + kfifo_free(&fh->rawir); + if (dev->driver_type != RC_DRIVER_IR_RAW_TX) + kfifo_free(&fh->scancodes); + kfree(fh); + + rc_close(dev); + put_device(&dev->dev); + + return 0; +} + +static ssize_t lirc_transmit(struct file *file, const char __user *buf, + size_t n, loff_t *ppos) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *dev = fh->rc; + unsigned int *txbuf; + struct ir_raw_event *raw = NULL; + ssize_t ret; + size_t count; + ktime_t start; + s64 towait; + unsigned int duration = 0; /* signal duration in us */ + int i; + + ret = mutex_lock_interruptible(&dev->lock); + if (ret) + return ret; + + if (!dev->registered) { + ret = -ENODEV; + goto out_unlock; + } + + if (!dev->tx_ir) { + ret = -EINVAL; + goto out_unlock; + } + + if (fh->send_mode == LIRC_MODE_SCANCODE) { + struct lirc_scancode scan; + + if (n != sizeof(scan)) { + ret = -EINVAL; + goto out_unlock; + } + + if (copy_from_user(&scan, buf, sizeof(scan))) { + ret = -EFAULT; + goto out_unlock; + } + + if (scan.flags || scan.keycode || scan.timestamp) { + ret = -EINVAL; + goto out_unlock; + } + + /* We only have encoders for 32-bit protocols. */ + if (scan.scancode > U32_MAX || + !rc_validate_scancode(scan.rc_proto, scan.scancode)) { + ret = -EINVAL; + goto out_unlock; + } + + raw = kmalloc_array(LIRCBUF_SIZE, sizeof(*raw), GFP_KERNEL); + if (!raw) { + ret = -ENOMEM; + goto out_unlock; + } + + ret = ir_raw_encode_scancode(scan.rc_proto, scan.scancode, + raw, LIRCBUF_SIZE); + if (ret < 0) + goto out_kfree_raw; + + /* drop trailing space */ + if (!(ret % 2)) + count = ret - 1; + else + count = ret; + + txbuf = kmalloc_array(count, sizeof(unsigned int), GFP_KERNEL); + if (!txbuf) { + ret = -ENOMEM; + goto out_kfree_raw; + } + + for (i = 0; i < count; i++) + txbuf[i] = raw[i].duration; + + if (dev->s_tx_carrier) { + int carrier = ir_raw_encode_carrier(scan.rc_proto); + + if (carrier > 0) + dev->s_tx_carrier(dev, carrier); + } + } else { + if (n < sizeof(unsigned int) || n % sizeof(unsigned int)) { + ret = -EINVAL; + goto out_unlock; + } + + count = n / sizeof(unsigned int); + if (count > LIRCBUF_SIZE || count % 2 == 0) { + ret = -EINVAL; + goto out_unlock; + } + + txbuf = memdup_user(buf, n); + if (IS_ERR(txbuf)) { + ret = PTR_ERR(txbuf); + goto out_unlock; + } + } + + for (i = 0; i < count; i++) { + if (txbuf[i] > IR_MAX_DURATION - duration || !txbuf[i]) { + ret = -EINVAL; + goto out_kfree; + } + + duration += txbuf[i]; + } + + start = ktime_get(); + + ret = dev->tx_ir(dev, txbuf, count); + if (ret < 0) + goto out_kfree; + + kfree(txbuf); + kfree(raw); + mutex_unlock(&dev->lock); + + /* + * The lircd gap calculation expects the write function to + * wait for the actual IR signal to be transmitted before + * returning. + */ + towait = ktime_us_delta(ktime_add_us(start, duration), + ktime_get()); + if (towait > 0) { + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(usecs_to_jiffies(towait)); + } + + return n; +out_kfree: + kfree(txbuf); +out_kfree_raw: + kfree(raw); +out_unlock: + mutex_unlock(&dev->lock); + return ret; +} + +static long lirc_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *dev = fh->rc; + u32 __user *argp = (u32 __user *)(arg); + u32 val = 0; + int ret; + + if (_IOC_DIR(cmd) & _IOC_WRITE) { + ret = get_user(val, argp); + if (ret) + return ret; + } + + ret = mutex_lock_interruptible(&dev->lock); + if (ret) + return ret; + + if (!dev->registered) { + ret = -ENODEV; + goto out; + } + + switch (cmd) { + case LIRC_GET_FEATURES: + if (dev->driver_type == RC_DRIVER_SCANCODE) + val |= LIRC_CAN_REC_SCANCODE; + + if (dev->driver_type == RC_DRIVER_IR_RAW) { + val |= LIRC_CAN_REC_MODE2; + if (dev->rx_resolution) + val |= LIRC_CAN_GET_REC_RESOLUTION; + } + + if (dev->tx_ir) { + val |= LIRC_CAN_SEND_PULSE; + if (dev->s_tx_mask) + val |= LIRC_CAN_SET_TRANSMITTER_MASK; + if (dev->s_tx_carrier) + val |= LIRC_CAN_SET_SEND_CARRIER; + if (dev->s_tx_duty_cycle) + val |= LIRC_CAN_SET_SEND_DUTY_CYCLE; + } + + if (dev->s_rx_carrier_range) + val |= LIRC_CAN_SET_REC_CARRIER | + LIRC_CAN_SET_REC_CARRIER_RANGE; + + if (dev->s_learning_mode) + val |= LIRC_CAN_USE_WIDEBAND_RECEIVER; + + if (dev->s_carrier_report) + val |= LIRC_CAN_MEASURE_CARRIER; + + if (dev->max_timeout) + val |= LIRC_CAN_SET_REC_TIMEOUT; + + break; + + /* mode support */ + case LIRC_GET_REC_MODE: + if (dev->driver_type == RC_DRIVER_IR_RAW_TX) + ret = -ENOTTY; + else + val = fh->rec_mode; + break; + + case LIRC_SET_REC_MODE: + switch (dev->driver_type) { + case RC_DRIVER_IR_RAW_TX: + ret = -ENOTTY; + break; + case RC_DRIVER_SCANCODE: + if (val != LIRC_MODE_SCANCODE) + ret = -EINVAL; + break; + case RC_DRIVER_IR_RAW: + if (!(val == LIRC_MODE_MODE2 || + val == LIRC_MODE_SCANCODE)) + ret = -EINVAL; + break; + } + + if (!ret) + fh->rec_mode = val; + break; + + case LIRC_GET_SEND_MODE: + if (!dev->tx_ir) + ret = -ENOTTY; + else + val = fh->send_mode; + break; + + case LIRC_SET_SEND_MODE: + if (!dev->tx_ir) + ret = -ENOTTY; + else if (!(val == LIRC_MODE_PULSE || val == LIRC_MODE_SCANCODE)) + ret = -EINVAL; + else + fh->send_mode = val; + break; + + /* TX settings */ + case LIRC_SET_TRANSMITTER_MASK: + if (!dev->s_tx_mask) + ret = -ENOTTY; + else + ret = dev->s_tx_mask(dev, val); + break; + + case LIRC_SET_SEND_CARRIER: + if (!dev->s_tx_carrier) + ret = -ENOTTY; + else + ret = dev->s_tx_carrier(dev, val); + break; + + case LIRC_SET_SEND_DUTY_CYCLE: + if (!dev->s_tx_duty_cycle) + ret = -ENOTTY; + else if (val <= 0 || val >= 100) + ret = -EINVAL; + else + ret = dev->s_tx_duty_cycle(dev, val); + break; + + /* RX settings */ + case LIRC_SET_REC_CARRIER: + if (!dev->s_rx_carrier_range) + ret = -ENOTTY; + else if (val <= 0) + ret = -EINVAL; + else + ret = dev->s_rx_carrier_range(dev, fh->carrier_low, + val); + break; + + case LIRC_SET_REC_CARRIER_RANGE: + if (!dev->s_rx_carrier_range) + ret = -ENOTTY; + else if (val <= 0) + ret = -EINVAL; + else + fh->carrier_low = val; + break; + + case LIRC_GET_REC_RESOLUTION: + if (!dev->rx_resolution) + ret = -ENOTTY; + else + val = dev->rx_resolution; + break; + + case LIRC_SET_WIDEBAND_RECEIVER: + if (!dev->s_learning_mode) + ret = -ENOTTY; + else + ret = dev->s_learning_mode(dev, !!val); + break; + + case LIRC_SET_MEASURE_CARRIER_MODE: + if (!dev->s_carrier_report) + ret = -ENOTTY; + else + ret = dev->s_carrier_report(dev, !!val); + break; + + /* Generic timeout support */ + case LIRC_GET_MIN_TIMEOUT: + if (!dev->max_timeout) + ret = -ENOTTY; + else + val = dev->min_timeout; + break; + + case LIRC_GET_MAX_TIMEOUT: + if (!dev->max_timeout) + ret = -ENOTTY; + else + val = dev->max_timeout; + break; + + case LIRC_SET_REC_TIMEOUT: + if (!dev->max_timeout) { + ret = -ENOTTY; + } else { + if (val < dev->min_timeout || val > dev->max_timeout) + ret = -EINVAL; + else if (dev->s_timeout) + ret = dev->s_timeout(dev, val); + else + dev->timeout = val; + } + break; + + case LIRC_GET_REC_TIMEOUT: + if (!dev->timeout) + ret = -ENOTTY; + else + val = dev->timeout; + break; + + case LIRC_SET_REC_TIMEOUT_REPORTS: + if (dev->driver_type != RC_DRIVER_IR_RAW) + ret = -ENOTTY; + else + fh->send_timeout_reports = !!val; + break; + + default: + ret = -ENOTTY; + } + + if (!ret && _IOC_DIR(cmd) & _IOC_READ) + ret = put_user(val, argp); + +out: + mutex_unlock(&dev->lock); + return ret; +} + +static __poll_t lirc_poll(struct file *file, struct poll_table_struct *wait) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *rcdev = fh->rc; + __poll_t events = 0; + + poll_wait(file, &fh->wait_poll, wait); + + if (!rcdev->registered) { + events = EPOLLHUP | EPOLLERR; + } else if (rcdev->driver_type != RC_DRIVER_IR_RAW_TX) { + if (fh->rec_mode == LIRC_MODE_SCANCODE && + !kfifo_is_empty(&fh->scancodes)) + events = EPOLLIN | EPOLLRDNORM; + + if (fh->rec_mode == LIRC_MODE_MODE2 && + !kfifo_is_empty(&fh->rawir)) + events = EPOLLIN | EPOLLRDNORM; + } + + return events; +} + +static ssize_t lirc_read_mode2(struct file *file, char __user *buffer, + size_t length) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *rcdev = fh->rc; + unsigned int copied; + int ret; + + if (length < sizeof(unsigned int) || length % sizeof(unsigned int)) + return -EINVAL; + + do { + if (kfifo_is_empty(&fh->rawir)) { + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(fh->wait_poll, + !kfifo_is_empty(&fh->rawir) || + !rcdev->registered); + if (ret) + return ret; + } + + if (!rcdev->registered) + return -ENODEV; + + ret = mutex_lock_interruptible(&rcdev->lock); + if (ret) + return ret; + ret = kfifo_to_user(&fh->rawir, buffer, length, &copied); + mutex_unlock(&rcdev->lock); + if (ret) + return ret; + } while (copied == 0); + + return copied; +} + +static ssize_t lirc_read_scancode(struct file *file, char __user *buffer, + size_t length) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *rcdev = fh->rc; + unsigned int copied; + int ret; + + if (length < sizeof(struct lirc_scancode) || + length % sizeof(struct lirc_scancode)) + return -EINVAL; + + do { + if (kfifo_is_empty(&fh->scancodes)) { + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + ret = wait_event_interruptible(fh->wait_poll, + !kfifo_is_empty(&fh->scancodes) || + !rcdev->registered); + if (ret) + return ret; + } + + if (!rcdev->registered) + return -ENODEV; + + ret = mutex_lock_interruptible(&rcdev->lock); + if (ret) + return ret; + ret = kfifo_to_user(&fh->scancodes, buffer, length, &copied); + mutex_unlock(&rcdev->lock); + if (ret) + return ret; + } while (copied == 0); + + return copied; +} + +static ssize_t lirc_read(struct file *file, char __user *buffer, size_t length, + loff_t *ppos) +{ + struct lirc_fh *fh = file->private_data; + struct rc_dev *rcdev = fh->rc; + + if (rcdev->driver_type == RC_DRIVER_IR_RAW_TX) + return -EINVAL; + + if (!rcdev->registered) + return -ENODEV; + + if (fh->rec_mode == LIRC_MODE_MODE2) + return lirc_read_mode2(file, buffer, length); + else /* LIRC_MODE_SCANCODE */ + return lirc_read_scancode(file, buffer, length); +} + +static const struct file_operations lirc_fops = { + .owner = THIS_MODULE, + .write = lirc_transmit, + .unlocked_ioctl = lirc_ioctl, + .compat_ioctl = compat_ptr_ioctl, + .read = lirc_read, + .poll = lirc_poll, + .open = lirc_open, + .release = lirc_close, + .llseek = no_llseek, +}; + +static void lirc_release_device(struct device *ld) +{ + struct rc_dev *rcdev = container_of(ld, struct rc_dev, lirc_dev); + + put_device(&rcdev->dev); +} + +int lirc_register(struct rc_dev *dev) +{ + const char *rx_type, *tx_type; + int err, minor; + + minor = ida_simple_get(&lirc_ida, 0, RC_DEV_MAX, GFP_KERNEL); + if (minor < 0) + return minor; + + device_initialize(&dev->lirc_dev); + dev->lirc_dev.class = lirc_class; + dev->lirc_dev.parent = &dev->dev; + dev->lirc_dev.release = lirc_release_device; + dev->lirc_dev.devt = MKDEV(MAJOR(lirc_base_dev), minor); + dev_set_name(&dev->lirc_dev, "lirc%d", minor); + + INIT_LIST_HEAD(&dev->lirc_fh); + spin_lock_init(&dev->lirc_fh_lock); + + cdev_init(&dev->lirc_cdev, &lirc_fops); + + err = cdev_device_add(&dev->lirc_cdev, &dev->lirc_dev); + if (err) + goto out_ida; + + get_device(&dev->dev); + + switch (dev->driver_type) { + case RC_DRIVER_SCANCODE: + rx_type = "scancode"; + break; + case RC_DRIVER_IR_RAW: + rx_type = "raw IR"; + break; + default: + rx_type = "no"; + break; + } + + if (dev->tx_ir) + tx_type = "raw IR"; + else + tx_type = "no"; + + dev_info(&dev->dev, "lirc_dev: driver %s registered at minor = %d, %s receiver, %s transmitter", + dev->driver_name, minor, rx_type, tx_type); + + return 0; + +out_ida: + ida_simple_remove(&lirc_ida, minor); + return err; +} + +void lirc_unregister(struct rc_dev *dev) +{ + unsigned long flags; + struct lirc_fh *fh; + + dev_dbg(&dev->dev, "lirc_dev: driver %s unregistered from minor = %d\n", + dev->driver_name, MINOR(dev->lirc_dev.devt)); + + spin_lock_irqsave(&dev->lirc_fh_lock, flags); + list_for_each_entry(fh, &dev->lirc_fh, list) + wake_up_poll(&fh->wait_poll, EPOLLHUP | EPOLLERR); + spin_unlock_irqrestore(&dev->lirc_fh_lock, flags); + + cdev_device_del(&dev->lirc_cdev, &dev->lirc_dev); + ida_simple_remove(&lirc_ida, MINOR(dev->lirc_dev.devt)); +} + +int __init lirc_dev_init(void) +{ + int retval; + + lirc_class = class_create(THIS_MODULE, "lirc"); + if (IS_ERR(lirc_class)) { + pr_err("class_create failed\n"); + return PTR_ERR(lirc_class); + } + + retval = alloc_chrdev_region(&lirc_base_dev, 0, RC_DEV_MAX, "lirc"); + if (retval) { + class_destroy(lirc_class); + pr_err("alloc_chrdev_region failed\n"); + return retval; + } + + pr_debug("IR Remote Control driver registered, major %d\n", + MAJOR(lirc_base_dev)); + + return 0; +} + +void __exit lirc_dev_exit(void) +{ + class_destroy(lirc_class); + unregister_chrdev_region(lirc_base_dev, RC_DEV_MAX); +} + +struct rc_dev *rc_dev_get_from_fd(int fd) +{ + struct fd f = fdget(fd); + struct lirc_fh *fh; + struct rc_dev *dev; + + if (!f.file) + return ERR_PTR(-EBADF); + + if (f.file->f_op != &lirc_fops) { + fdput(f); + return ERR_PTR(-EINVAL); + } + + fh = f.file->private_data; + dev = fh->rc; + + get_device(&dev->dev); + fdput(f); + + return dev; +} + +MODULE_ALIAS("lirc_dev"); |