diff options
Diffstat (limited to 'drivers/iio/industrialio-buffer.c')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 127 |
1 files changed, 125 insertions, 2 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index 4209e933ab80..b884d78657cb 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -120,6 +120,9 @@ static ssize_t iio_buffer_read(struct file *filp, char __user *buf, if (!rb || !rb->access->read) return -EINVAL; + if (rb->direction != IIO_BUFFER_DIRECTION_IN) + return -EPERM; + datum_size = rb->bytes_per_datum; /* @@ -161,6 +164,65 @@ static ssize_t iio_buffer_read(struct file *filp, char __user *buf, return ret; } +static size_t iio_buffer_space_available(struct iio_buffer *buf) +{ + if (buf->access->space_available) + return buf->access->space_available(buf); + + return SIZE_MAX; +} + +static ssize_t iio_buffer_write(struct file *filp, const char __user *buf, + size_t n, loff_t *f_ps) +{ + struct iio_dev_buffer_pair *ib = filp->private_data; + struct iio_buffer *rb = ib->buffer; + struct iio_dev *indio_dev = ib->indio_dev; + DEFINE_WAIT_FUNC(wait, woken_wake_function); + int ret; + size_t written; + + if (!indio_dev->info) + return -ENODEV; + + if (!rb || !rb->access->write) + return -EINVAL; + + if (rb->direction != IIO_BUFFER_DIRECTION_OUT) + return -EPERM; + + written = 0; + add_wait_queue(&rb->pollq, &wait); + do { + if (indio_dev->info == NULL) + return -ENODEV; + + if (!iio_buffer_space_available(rb)) { + if (signal_pending(current)) { + ret = -ERESTARTSYS; + break; + } + + wait_woken(&wait, TASK_INTERRUPTIBLE, + MAX_SCHEDULE_TIMEOUT); + continue; + } + + ret = rb->access->write(rb, n - written, buf + written); + if (ret == 0 && (filp->f_flags & O_NONBLOCK)) + ret = -EAGAIN; + + if (ret > 0) { + written += ret; + if (written != n && !(filp->f_flags & O_NONBLOCK)) + continue; + } + } while (ret == 0); + remove_wait_queue(&rb->pollq, &wait); + + return ret < 0 ? ret : n; +} + /** * iio_buffer_poll() - poll the buffer to find out if it has data * @filp: File structure pointer for device access @@ -181,8 +243,18 @@ static __poll_t iio_buffer_poll(struct file *filp, return 0; poll_wait(filp, &rb->pollq, wait); - if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0)) - return EPOLLIN | EPOLLRDNORM; + + switch (rb->direction) { + case IIO_BUFFER_DIRECTION_IN: + if (iio_buffer_ready(indio_dev, rb, rb->watermark, 0)) + return EPOLLIN | EPOLLRDNORM; + break; + case IIO_BUFFER_DIRECTION_OUT: + if (iio_buffer_space_available(rb)) + return EPOLLOUT | EPOLLWRNORM; + break; + } + return 0; } @@ -199,6 +271,19 @@ ssize_t iio_buffer_read_wrapper(struct file *filp, char __user *buf, return iio_buffer_read(filp, buf, n, f_ps); } +ssize_t iio_buffer_write_wrapper(struct file *filp, const char __user *buf, + size_t n, loff_t *f_ps) +{ + struct iio_dev_buffer_pair *ib = filp->private_data; + struct iio_buffer *rb = ib->buffer; + + /* check if buffer was opened through new API */ + if (test_bit(IIO_BUSY_BIT_POS, &rb->flags)) + return -EBUSY; + + return iio_buffer_write(filp, buf, n, f_ps); +} + __poll_t iio_buffer_poll_wrapper(struct file *filp, struct poll_table_struct *wait) { @@ -231,6 +316,15 @@ void iio_buffer_wakeup_poll(struct iio_dev *indio_dev) } } +int iio_pop_from_buffer(struct iio_buffer *buffer, void *data) +{ + if (!buffer || !buffer->access || !buffer->access->remove_from) + return -EINVAL; + + return buffer->access->remove_from(buffer, data); +} +EXPORT_SYMBOL_GPL(iio_pop_from_buffer); + void iio_buffer_init(struct iio_buffer *buffer) { INIT_LIST_HEAD(&buffer->demux_list); @@ -1156,6 +1250,10 @@ int iio_update_buffers(struct iio_dev *indio_dev, if (insert_buffer == remove_buffer) return 0; + if (insert_buffer && + (insert_buffer->direction == IIO_BUFFER_DIRECTION_OUT)) + return -EINVAL; + mutex_lock(&iio_dev_opaque->info_exist_lock); mutex_lock(&indio_dev->mlock); @@ -1277,6 +1375,22 @@ static ssize_t iio_dma_show_data_available(struct device *dev, return sysfs_emit(buf, "%zu\n", iio_buffer_data_available(buffer)); } +static ssize_t direction_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_buffer *buffer = to_iio_dev_attr(attr)->buffer; + + switch (buffer->direction) { + case IIO_BUFFER_DIRECTION_IN: + return sprintf(buf, "in\n"); + case IIO_BUFFER_DIRECTION_OUT: + return sprintf(buf, "out\n"); + default: + return -EINVAL; + } +} + static DEVICE_ATTR(length, S_IRUGO | S_IWUSR, iio_buffer_read_length, iio_buffer_write_length); static struct device_attribute dev_attr_length_ro = __ATTR(length, @@ -1289,12 +1403,20 @@ static struct device_attribute dev_attr_watermark_ro = __ATTR(watermark, S_IRUGO, iio_buffer_show_watermark, NULL); static DEVICE_ATTR(data_available, S_IRUGO, iio_dma_show_data_available, NULL); +static DEVICE_ATTR_RO(direction); +/* + * When adding new attributes here, put the at the end, at least until + * the code that handles the length/length_ro & watermark/watermark_ro + * assignments gets cleaned up. Otherwise these can create some weird + * duplicate attributes errors under some setups. + */ static struct attribute *iio_buffer_attrs[] = { &dev_attr_length.attr, &dev_attr_enable.attr, &dev_attr_watermark.attr, &dev_attr_data_available.attr, + &dev_attr_direction.attr, }; #define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr) @@ -1397,6 +1519,7 @@ static const struct file_operations iio_buffer_chrdev_fileops = { .owner = THIS_MODULE, .llseek = noop_llseek, .read = iio_buffer_read, + .write = iio_buffer_write, .poll = iio_buffer_poll, .release = iio_buffer_chrdev_release, }; |