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| author |   Matt Fornero <matt.fornero@mathworks.com> | 2017-12-06 14:43:30 -0500 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-01-08 16:03:41 +0100 |
| commit | 350f6c75f6933d5d58548d68f9336543c56b4a02 (patch) | |
| tree | 056a75fe99ad2653d510bc2892574f5e6e1d3c70 /drivers/iio | |
| parent | iio: mma8452: replace license description with SPDX specifier (diff) | |
| download | linux-dev-350f6c75f6933d5d58548d68f9336543c56b4a02.tar.xz linux-dev-350f6c75f6933d5d58548d68f9336543c56b4a02.zip | |
iio: buffer: Expose data available
Add a sysfs attribute that exposes buffer data available to userspace.
This attribute can be checked at runtime to determine the overall buffer
fill level (across all allocated buffers).
Signed-off-by: Matt Fornero <matt.fornero@mathworks.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio')
| -rw-r--r-- | drivers/iio/industrialio-buffer.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index d2b465140a6b..eda2a0f1658f 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1198,6 +1198,18 @@ out: return ret ? ret : len; } +static ssize_t iio_dma_show_data_available(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + struct iio_dev *indio_dev = dev_to_iio_dev(dev); + size_t bytes; + + bytes = iio_buffer_data_available(indio_dev->buffer); + + return sprintf(buf, "%zu\n", bytes); +} + 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, @@ -1208,11 +1220,14 @@ static DEVICE_ATTR(watermark, S_IRUGO | S_IWUSR, iio_buffer_show_watermark, iio_buffer_store_watermark); 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 struct attribute *iio_buffer_attrs[] = { &dev_attr_length.attr, &dev_attr_enable.attr, &dev_attr_watermark.attr, + &dev_attr_data_available.attr, }; int iio_buffer_alloc_sysfs_and_mask(struct iio_dev *indio_dev) |