diff options
| author | Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> | 2017-04-07 19:22:06 -0700 |
|---|---|---|
| committer | Jonathan Cameron <jic23@kernel.org> | 2017-05-16 19:44:01 +0100 |
| commit | 138bc7969c24c6cbba28e919c2376ad10a46fc60 (patch) | |
| tree | 0de82ecba4edebb0bcd40fc10663b952027bdf24 /Documentation/ABI/testing/sysfs-bus-iio | |
| parent | 371894f5d1a00cd6c03aab0beb9789b474ea46b0 (diff) | |
iio: hid-sensor-hub: Implement batch mode
HID sensor hubs using Integrated Senor Hub (ISH) has added capability to
support batch mode. This allows host processor to go to sleep for extended
duration, while the sensor hub is storing samples in its internal buffers.
'Commit f4f4673b7535 ("iio: add support for hardware fifo")' implements
feature in IIO core to implement such feature. This feature is used in
bmc150-accel-core.c to implement batch mode. This implementation allows
software device buffer watermark to be used as a hint to adjust hardware
FIFO.
But HID sensor hubs don't allow to change internal buffer size of FIFOs.
Instead an additional usage id to set "maximum report latency" is defined.
This allows host to go to sleep upto this latency period without getting
any report. Since there is no ABI to set this latency, a new attribute
"hwfifo_timeout" is added so that user mode can specify a latency.
This change checks presence of usage id to get/set maximum report latency
and if present, it will expose hwfifo_timeout.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-bus-iio')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-bus-iio | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio index 8c24d0892f61..2db2cdf42d54 100644 --- a/Documentation/ABI/testing/sysfs-bus-iio +++ b/Documentation/ABI/testing/sysfs-bus-iio @@ -1425,6 +1425,17 @@ Description: guarantees that the hardware fifo is flushed to the device buffer. +What: /sys/bus/iio/devices/iio:device*/buffer/hwfifo_timeout +KernelVersion: 4.12 +Contact: linux-iio@vger.kernel.org +Description: + A read/write property to provide capability to delay reporting of + samples till a timeout is reached. This allows host processors to + sleep, while the sensor is storing samples in its internal fifo. + The maximum timeout in seconds can be specified by setting + hwfifo_timeout.The current delay can be read by reading + hwfifo_timeout. A value of 0 means that there is no timeout. + What: /sys/bus/iio/devices/iio:deviceX/buffer/hwfifo_watermark KernelVersion: 4.2 Contact: linux-iio@vger.kernel.org |