* @hwnum: hardware number of the GPIO for this chip
*
* Returns:
- * A pointer to the GPIO descriptor or %ERR_PTR(-EINVAL) if no GPIO exists
+ * A pointer to the GPIO descriptor or ``ERR_PTR(-EINVAL)`` if no GPIO exists
* in the given chip for the specified hardware number.
*/
struct gpio_desc *gpiochip_get_desc(struct gpio_chip *chip,
struct gpio_device *gdev;
unsigned long flags;
+ if (!name)
+ return NULL;
+
spin_lock_irqsave(&gpio_lock, flags);
list_for_each_entry(gdev, &gpio_devices, list) {
for (i = 0; i != gdev->ngpio; ++i) {
struct gpio_desc *desc = &gdev->descs[i];
- if (!desc->name || !name)
+ if (!desc->name)
continue;
if (!strcmp(desc->name, name)) {
if (ret)
return ret;
}
+
+ atomic_notifier_call_chain(&desc->gdev->notifier,
+ GPIOLINE_CHANGED_CONFIG, desc);
}
return 0;
}
* @irq: the interrupt that trigger in response to events on this GPIO
* @wait: wait queue that handles blocking reads of events
* @events: KFIFO for the GPIO events
- * @read_lock: mutex lock to protect reads from colliding with adding
- * new events to the FIFO
* @timestamp: cache for the timestamp storing it between hardirq
* and IRQ thread, used to bring the timestamp close to the actual
* event
int irq;
wait_queue_head_t wait;
DECLARE_KFIFO(events, struct gpioevent_data, 16);
- struct mutex read_lock;
u64 timestamp;
};
poll_wait(filep, &le->wait, wait);
- if (!kfifo_is_empty(&le->events))
+ if (!kfifo_is_empty_spinlocked_noirqsave(&le->events, &le->wait.lock))
events = EPOLLIN | EPOLLRDNORM;
return events;
loff_t *f_ps)
{
struct lineevent_state *le = filep->private_data;
- unsigned int copied;
+ struct gpioevent_data ge;
+ ssize_t bytes_read = 0;
int ret;
- if (count < sizeof(struct gpioevent_data))
+ if (count < sizeof(ge))
return -EINVAL;
do {
+ spin_lock(&le->wait.lock);
if (kfifo_is_empty(&le->events)) {
- if (filep->f_flags & O_NONBLOCK)
+ if (bytes_read) {
+ spin_unlock(&le->wait.lock);
+ return bytes_read;
+ }
+
+ if (filep->f_flags & O_NONBLOCK) {
+ spin_unlock(&le->wait.lock);
return -EAGAIN;
+ }
- ret = wait_event_interruptible(le->wait,
+ ret = wait_event_interruptible_locked(le->wait,
!kfifo_is_empty(&le->events));
- if (ret)
+ if (ret) {
+ spin_unlock(&le->wait.lock);
return ret;
+ }
}
- if (mutex_lock_interruptible(&le->read_lock))
- return -ERESTARTSYS;
- ret = kfifo_to_user(&le->events, buf, count, &copied);
- mutex_unlock(&le->read_lock);
-
- if (ret)
- return ret;
-
- /*
- * If we couldn't read anything from the fifo (a different
- * thread might have been faster) we either return -EAGAIN if
- * the file descriptor is non-blocking, otherwise we go back to
- * sleep and wait for more data to arrive.
- */
- if (copied == 0 && (filep->f_flags & O_NONBLOCK))
- return -EAGAIN;
+ ret = kfifo_out(&le->events, &ge, 1);
+ spin_unlock(&le->wait.lock);
+ if (ret != 1) {
+ /*
+ * This should never happen - we were holding the lock
+ * from the moment we learned the fifo is no longer
+ * empty until now.
+ */
+ ret = -EIO;
+ break;
+ }
- } while (copied == 0);
+ if (copy_to_user(buf + bytes_read, &ge, sizeof(ge)))
+ return -EFAULT;
+ bytes_read += sizeof(ge);
+ } while (count >= bytes_read + sizeof(ge));
- return copied;
+ return bytes_read;
}
static int lineevent_release(struct inode *inode, struct file *filep)
* we didn't get the timestamp from lineevent_irq_handler().
*/
if (!le->timestamp)
- ge.timestamp = ktime_get_real_ns();
+ ge.timestamp = ktime_get_ns();
else
ge.timestamp = le->timestamp;
return IRQ_NONE;
}
- ret = kfifo_put(&le->events, ge);
+ ret = kfifo_in_spinlocked_noirqsave(&le->events, &ge,
+ 1, &le->wait.lock);
if (ret)
wake_up_poll(&le->wait, EPOLLIN);
+ else
+ pr_debug_ratelimited("event FIFO is full - event dropped\n");
return IRQ_HANDLED;
}
* Just store the timestamp in hardirq context so we get it as
* close in time as possible to the actual event.
*/
- le->timestamp = ktime_get_real_ns();
+ le->timestamp = ktime_get_ns();
return IRQ_WAKE_THREAD;
}
INIT_KFIFO(le->events);
init_waitqueue_head(&le->wait);
- mutex_init(&le->read_lock);
/* Request a thread to read the events */
ret = request_threaded_irq(le->irq,
return ret;
}
+static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
+ struct gpioline_info *info)
+{
+ struct gpio_chip *chip = desc->gdev->chip;
+ unsigned long flags;
+
+ spin_lock_irqsave(&gpio_lock, flags);
+
+ if (desc->name) {
+ strncpy(info->name, desc->name, sizeof(info->name));
+ info->name[sizeof(info->name) - 1] = '\0';
+ } else {
+ info->name[0] = '\0';
+ }
+
+ if (desc->label) {
+ strncpy(info->consumer, desc->label, sizeof(info->consumer));
+ info->consumer[sizeof(info->consumer) - 1] = '\0';
+ } else {
+ info->consumer[0] = '\0';
+ }
+
+ /*
+ * Userspace only need to know that the kernel is using this GPIO so
+ * it can't use it.
+ */
+ info->flags = 0;
+ if (test_bit(FLAG_REQUESTED, &desc->flags) ||
+ test_bit(FLAG_IS_HOGGED, &desc->flags) ||
+ test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
+ test_bit(FLAG_EXPORT, &desc->flags) ||
+ test_bit(FLAG_SYSFS, &desc->flags) ||
+ !pinctrl_gpio_can_use_line(chip->base + info->line_offset))
+ info->flags |= GPIOLINE_FLAG_KERNEL;
+ if (test_bit(FLAG_IS_OUT, &desc->flags))
+ info->flags |= GPIOLINE_FLAG_IS_OUT;
+ if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
+ info->flags |= GPIOLINE_FLAG_ACTIVE_LOW;
+ if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
+ info->flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
+ GPIOLINE_FLAG_IS_OUT);
+ if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
+ info->flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
+ GPIOLINE_FLAG_IS_OUT);
+ if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
+ info->flags |= GPIOLINE_FLAG_BIAS_DISABLE;
+ if (test_bit(FLAG_PULL_DOWN, &desc->flags))
+ info->flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
+ if (test_bit(FLAG_PULL_UP, &desc->flags))
+ info->flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
+
+ spin_unlock_irqrestore(&gpio_lock, flags);
+}
+
+struct gpio_chardev_data {
+ struct gpio_device *gdev;
+ wait_queue_head_t wait;
+ DECLARE_KFIFO(events, struct gpioline_info_changed, 32);
+ struct notifier_block lineinfo_changed_nb;
+ unsigned long *watched_lines;
+};
+
/*
* gpio_ioctl() - ioctl handler for the GPIO chardev
*/
static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
- struct gpio_device *gdev = filp->private_data;
+ struct gpio_chardev_data *priv = filp->private_data;
+ struct gpio_device *gdev = priv->gdev;
struct gpio_chip *chip = gdev->chip;
void __user *ip = (void __user *)arg;
+ struct gpio_desc *desc;
+ __u32 offset;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!chip)
if (copy_to_user(ip, &chipinfo, sizeof(chipinfo)))
return -EFAULT;
return 0;
- } else if (cmd == GPIO_GET_LINEINFO_IOCTL) {
+ } else if (cmd == GPIO_GET_LINEINFO_IOCTL ||
+ cmd == GPIO_GET_LINEINFO_WATCH_IOCTL) {
struct gpioline_info lineinfo;
- struct gpio_desc *desc;
if (copy_from_user(&lineinfo, ip, sizeof(lineinfo)))
return -EFAULT;
if (IS_ERR(desc))
return PTR_ERR(desc);
- if (desc->name) {
- strncpy(lineinfo.name, desc->name,
- sizeof(lineinfo.name));
- lineinfo.name[sizeof(lineinfo.name)-1] = '\0';
- } else {
- lineinfo.name[0] = '\0';
- }
- if (desc->label) {
- strncpy(lineinfo.consumer, desc->label,
- sizeof(lineinfo.consumer));
- lineinfo.consumer[sizeof(lineinfo.consumer)-1] = '\0';
- } else {
- lineinfo.consumer[0] = '\0';
- }
-
- /*
- * Userspace only need to know that the kernel is using
- * this GPIO so it can't use it.
- */
- lineinfo.flags = 0;
- if (test_bit(FLAG_REQUESTED, &desc->flags) ||
- test_bit(FLAG_IS_HOGGED, &desc->flags) ||
- test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
- test_bit(FLAG_EXPORT, &desc->flags) ||
- test_bit(FLAG_SYSFS, &desc->flags) ||
- !pinctrl_gpio_can_use_line(chip->base + lineinfo.line_offset))
- lineinfo.flags |= GPIOLINE_FLAG_KERNEL;
- if (test_bit(FLAG_IS_OUT, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_IS_OUT;
- if (test_bit(FLAG_ACTIVE_LOW, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_ACTIVE_LOW;
- if (test_bit(FLAG_OPEN_DRAIN, &desc->flags))
- lineinfo.flags |= (GPIOLINE_FLAG_OPEN_DRAIN |
- GPIOLINE_FLAG_IS_OUT);
- if (test_bit(FLAG_OPEN_SOURCE, &desc->flags))
- lineinfo.flags |= (GPIOLINE_FLAG_OPEN_SOURCE |
- GPIOLINE_FLAG_IS_OUT);
- if (test_bit(FLAG_BIAS_DISABLE, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_BIAS_DISABLE;
- if (test_bit(FLAG_PULL_DOWN, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_DOWN;
- if (test_bit(FLAG_PULL_UP, &desc->flags))
- lineinfo.flags |= GPIOLINE_FLAG_BIAS_PULL_UP;
+ gpio_desc_to_lineinfo(desc, &lineinfo);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
+
+ if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL)
+ set_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
+
return 0;
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
return linehandle_create(gdev, ip);
} else if (cmd == GPIO_GET_LINEEVENT_IOCTL) {
return lineevent_create(gdev, ip);
+ } else if (cmd == GPIO_GET_LINEINFO_UNWATCH_IOCTL) {
+ if (copy_from_user(&offset, ip, sizeof(offset)))
+ return -EFAULT;
+
+ desc = gpiochip_get_desc(chip, offset);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ clear_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
+ return 0;
}
return -EINVAL;
}
}
#endif
+static struct gpio_chardev_data *
+to_gpio_chardev_data(struct notifier_block *nb)
+{
+ return container_of(nb, struct gpio_chardev_data, lineinfo_changed_nb);
+}
+
+static int lineinfo_changed_notify(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct gpio_chardev_data *priv = to_gpio_chardev_data(nb);
+ struct gpioline_info_changed chg;
+ struct gpio_desc *desc = data;
+ int ret;
+
+ if (!test_bit(gpio_chip_hwgpio(desc), priv->watched_lines))
+ return NOTIFY_DONE;
+
+ memset(&chg, 0, sizeof(chg));
+ chg.info.line_offset = gpio_chip_hwgpio(desc);
+ chg.event_type = action;
+ chg.timestamp = ktime_get_ns();
+ gpio_desc_to_lineinfo(desc, &chg.info);
+
+ ret = kfifo_in_spinlocked(&priv->events, &chg, 1, &priv->wait.lock);
+ if (ret)
+ wake_up_poll(&priv->wait, EPOLLIN);
+ else
+ pr_debug_ratelimited("lineinfo event FIFO is full - event dropped\n");
+
+ return NOTIFY_OK;
+}
+
+static __poll_t lineinfo_watch_poll(struct file *filep,
+ struct poll_table_struct *pollt)
+{
+ struct gpio_chardev_data *priv = filep->private_data;
+ __poll_t events = 0;
+
+ poll_wait(filep, &priv->wait, pollt);
+
+ if (!kfifo_is_empty_spinlocked_noirqsave(&priv->events,
+ &priv->wait.lock))
+ events = EPOLLIN | EPOLLRDNORM;
+
+ return events;
+}
+
+static ssize_t lineinfo_watch_read(struct file *filep, char __user *buf,
+ size_t count, loff_t *off)
+{
+ struct gpio_chardev_data *priv = filep->private_data;
+ struct gpioline_info_changed event;
+ ssize_t bytes_read = 0;
+ int ret;
+
+ if (count < sizeof(event))
+ return -EINVAL;
+
+ do {
+ spin_lock(&priv->wait.lock);
+ if (kfifo_is_empty(&priv->events)) {
+ if (bytes_read) {
+ spin_unlock(&priv->wait.lock);
+ return bytes_read;
+ }
+
+ if (filep->f_flags & O_NONBLOCK) {
+ spin_unlock(&priv->wait.lock);
+ return -EAGAIN;
+ }
+
+ ret = wait_event_interruptible_locked(priv->wait,
+ !kfifo_is_empty(&priv->events));
+ if (ret) {
+ spin_unlock(&priv->wait.lock);
+ return ret;
+ }
+ }
+
+ ret = kfifo_out(&priv->events, &event, 1);
+ spin_unlock(&priv->wait.lock);
+ if (ret != 1) {
+ ret = -EIO;
+ break;
+ /* We should never get here. See lineevent_read(). */
+ }
+
+ if (copy_to_user(buf + bytes_read, &event, sizeof(event)))
+ return -EFAULT;
+ bytes_read += sizeof(event);
+ } while (count >= bytes_read + sizeof(event));
+
+ return bytes_read;
+}
+
/**
* gpio_chrdev_open() - open the chardev for ioctl operations
* @inode: inode for this chardev
{
struct gpio_device *gdev = container_of(inode->i_cdev,
struct gpio_device, chrdev);
+ struct gpio_chardev_data *priv;
+ int ret = -ENOMEM;
/* Fail on open if the backing gpiochip is gone */
if (!gdev->chip)
return -ENODEV;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->watched_lines = bitmap_zalloc(gdev->chip->ngpio, GFP_KERNEL);
+ if (!priv->watched_lines)
+ goto out_free_priv;
+
+ init_waitqueue_head(&priv->wait);
+ INIT_KFIFO(priv->events);
+ priv->gdev = gdev;
+
+ priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
+ ret = atomic_notifier_chain_register(&gdev->notifier,
+ &priv->lineinfo_changed_nb);
+ if (ret)
+ goto out_free_bitmap;
+
get_device(&gdev->dev);
- filp->private_data = gdev;
+ filp->private_data = priv;
+
+ ret = nonseekable_open(inode, filp);
+ if (ret)
+ goto out_unregister_notifier;
+
+ return ret;
- return nonseekable_open(inode, filp);
+out_unregister_notifier:
+ atomic_notifier_chain_unregister(&gdev->notifier,
+ &priv->lineinfo_changed_nb);
+out_free_bitmap:
+ bitmap_free(priv->watched_lines);
+out_free_priv:
+ kfree(priv);
+ return ret;
}
/**
*/
static int gpio_chrdev_release(struct inode *inode, struct file *filp)
{
- struct gpio_device *gdev = container_of(inode->i_cdev,
- struct gpio_device, chrdev);
+ struct gpio_chardev_data *priv = filp->private_data;
+ struct gpio_device *gdev = priv->gdev;
+ bitmap_free(priv->watched_lines);
+ atomic_notifier_chain_unregister(&gdev->notifier,
+ &priv->lineinfo_changed_nb);
put_device(&gdev->dev);
+ kfree(priv);
+
return 0;
}
-
static const struct file_operations gpio_fileops = {
.release = gpio_chrdev_release,
.open = gpio_chrdev_open,
+ .poll = lineinfo_watch_poll,
+ .read = lineinfo_watch_read,
.owner = THIS_MODULE,
.llseek = no_llseek,
.unlocked_ioctl = gpio_ioctl,
spin_unlock_irqrestore(&gpio_lock, flags);
+ ATOMIC_INIT_NOTIFIER_HEAD(&gdev->notifier);
+
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
#endif
void gpiochip_remove(struct gpio_chip *chip)
{
struct gpio_device *gdev = chip->gpiodev;
- struct gpio_desc *desc;
unsigned long flags;
- unsigned i;
- bool requested = false;
+ unsigned int i;
/* FIXME: should the legacy sysfs handling be moved to gpio_device? */
gpiochip_sysfs_unregister(gdev);
spin_lock_irqsave(&gpio_lock, flags);
for (i = 0; i < gdev->ngpio; i++) {
- desc = &gdev->descs[i];
- if (test_bit(FLAG_REQUESTED, &desc->flags))
- requested = true;
+ if (gpiochip_is_requested(chip, i))
+ break;
}
spin_unlock_irqrestore(&gpio_lock, flags);
- if (requested)
+ if (i != gdev->ngpio)
dev_crit(&gdev->dev,
"REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n");
}
EXPORT_SYMBOL_GPL(gpiochip_remove);
-static void devm_gpio_chip_release(struct device *dev, void *res)
-{
- struct gpio_chip *chip = *(struct gpio_chip **)res;
-
- gpiochip_remove(chip);
-}
-
-/**
- * devm_gpiochip_add_data() - Resource managed gpiochip_add_data()
- * @dev: pointer to the device that gpio_chip belongs to.
- * @chip: the chip to register, with chip->base initialized
- * @data: driver-private data associated with this chip
- *
- * Context: potentially before irqs will work
- *
- * The gpio chip automatically be released when the device is unbound.
- *
- * Returns:
- * A negative errno if the chip can't be registered, such as because the
- * chip->base is invalid or already associated with a different chip.
- * Otherwise it returns zero as a success code.
- */
-int devm_gpiochip_add_data(struct device *dev, struct gpio_chip *chip,
- void *data)
-{
- struct gpio_chip **ptr;
- int ret;
-
- ptr = devres_alloc(devm_gpio_chip_release, sizeof(*ptr),
- GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
-
- ret = gpiochip_add_data(chip, data);
- if (ret < 0) {
- devres_free(ptr);
- return ret;
- }
-
- *ptr = chip;
- devres_add(dev, ptr);
-
- return 0;
-}
-EXPORT_SYMBOL_GPL(devm_gpiochip_add_data);
-
/**
* gpiochip_find() - iterator for locating a specific gpio_chip
* @data: data to pass to match function
*/
int gpiochip_generic_request(struct gpio_chip *chip, unsigned offset)
{
- return pinctrl_gpio_request(chip->gpiodev->base + offset);
+ if (!list_empty(&chip->gpiodev->pin_ranges))
+ return pinctrl_gpio_request(chip->gpiodev->base + offset);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(gpiochip_generic_request);
}
done:
spin_unlock_irqrestore(&gpio_lock, flags);
+ atomic_notifier_call_chain(&desc->gdev->notifier,
+ GPIOLINE_CHANGED_REQUESTED, desc);
return ret;
}
clear_bit(FLAG_PULL_DOWN, &desc->flags);
clear_bit(FLAG_BIAS_DISABLE, &desc->flags);
clear_bit(FLAG_IS_HOGGED, &desc->flags);
+#ifdef CONFIG_OF_DYNAMIC
+ desc->hog = NULL;
+#endif
ret = true;
}
spin_unlock_irqrestore(&gpio_lock, flags);
+ atomic_notifier_call_chain(&desc->gdev->notifier,
+ GPIOLINE_CHANGED_RELEASED, desc);
+
return ret;
}
if (offset >= chip->ngpio)
return NULL;
- desc = &chip->gpiodev->descs[offset];
+ desc = gpiochip_get_desc(chip, offset);
+ if (IS_ERR(desc))
+ return NULL;
if (test_bit(FLAG_REQUESTED, &desc->flags) == 0)
return NULL;
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
bus_unregister(&gpio_bus_type);
- } else {
- gpiolib_initialized = true;
- gpiochip_setup_devs();
+ return ret;
}
+
+ gpiolib_initialized = true;
+ gpiochip_setup_devs();
+
+ if (IS_ENABLED(CONFIG_OF_DYNAMIC))
+ WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
+
return ret;
}
core_initcall(gpiolib_dev_init);
projects / platform / kernel / linux-rpi.git / blobdiff