linux/drivers/media/rc/lirc_dev.c
Sean Young 68a99f6a0e media: lirc: report ir receiver overflow
If the driver reports that the hardware had an overflow, report this to
userspace. It would be nice to know when this happens, and not just get
a long space.

This change has been tested with lircd, ir-ctl, and ir-keytable.

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
2022-01-28 19:32:50 +01:00

837 lines
18 KiB
C

// 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;
/* Receiver overflow, data missing */
if (ev.overflow) {
/*
* Send lirc overflow message. This message is unknown to
* lircd, but it will interpret this as a long space as
* long as the value is set to high value. This resets its
* decoder state.
*/
sample = LIRC_OVERFLOW(LIRC_VALUE_MASK);
dev_dbg(&dev->dev, "delivering overflow 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) {
dev->gap_start = ktime_get();
sample = LIRC_TIMEOUT(ev.duration);
dev_dbg(&dev->dev, "timeout report (duration: %d)\n", sample);
/* Normal sample */
} else {
if (dev->gap_start) {
u64 duration = ktime_us_delta(ktime_get(),
dev->gap_start);
/* Cap by LIRC_VALUE_MASK */
duration = min_t(u64, 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(duration));
spin_unlock_irqrestore(&dev->lirc_fh_lock, flags);
dev->gap_start = 0;
}
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 (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;
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 ||
scan.rc_proto > RC_PROTO_MAX) {
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;
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_wideband_receiver)
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_wideband_receiver)
ret = -ENOTTY;
else
ret = dev->s_wideband_receiver(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;
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");