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Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-iio | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio index 0b6f0abf3370..6bf79072179f 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio +++ b/Documentation/ABI/testing/sysfs-bus-iio @@ -1295,3 +1295,72 @@ Description: allows the application to block on poll with a timeout and read the available samples after the timeout expires and thus have a maximum delay guarantee. + +What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_enabled +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + A read-only boolean value that indicates if the hardware fifo is + currently enabled or disabled. If the device does not have a + hardware fifo this entry is not present. + The hardware fifo is enabled when the buffer is enabled if the + current hardware fifo watermark level is set and other current + device settings allows it (e.g. if a trigger is set that samples + data differently that the hardware fifo does then hardware fifo + will not enabled). + If the hardware fifo is enabled and the level of the hardware + fifo reaches the hardware fifo watermark level the device will + flush its hardware fifo to the device buffer. Doing a non + blocking read on the device when no samples are present in the + device buffer will also force a flush. + When the hardware fifo is enabled there is no need to use a + trigger to use buffer mode since the watermark settings + guarantees that the hardware fifo is flushed to the device + buffer. + +What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + Read-only entry that contains a single integer specifying the + current watermark level for the hardware fifo. If the device + does not have a hardware fifo this entry is not present. + The watermark level for the hardware fifo is set by the driver + based on the value set by the user in buffer/watermark but + taking into account hardware limitations (e.g. most hardware + buffers are limited to 32-64 samples, some hardware buffers + watermarks are fixed or have minimum levels). A value of 0 + means that the hardware watermark is unset. + +What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_min +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + A single positive integer specifying the minimum watermark level + for the hardware fifo of this device. If the device does not + have a hardware fifo this entry is not present. + If the user sets buffer/watermark to a value less than this one, + then the hardware watermark will remain unset. + +What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_max +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + A single positive integer specifying the maximum watermark level + for the hardware fifo of this device. If the device does not + have a hardware fifo this entry is not present. + If the user sets buffer/watermark to a value greater than this + one, then the hardware watermark will be capped at this value. + +What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark_available +KernelVersion: 4.2 +Contact: linux-iio@vger.kernel.org +Description: + A list of positive integers specifying the available watermark + levels for the hardware fifo. This entry is optional and if it + is not present it means that all the values between + hwfifo_watermark_min and hwfifo_watermark_max are supported. + If the user sets buffer/watermark to a value greater than + hwfifo_watermak_min but not equal to any of the values in this + list, the driver will chose an appropriate value for the + hardware fifo watermark level. |