mirror of
https://github.com/torvalds/linux.git
synced 2024-12-03 17:41:22 +00:00
28e5d3bb03
The ACCES 104-QUAD-8 is a general purpose quadrature encoder counter/interface board. The 104-QUAD-8 is capable of monitoring the outputs of eight encoders via four on-board LSI/CSI LS7266R1 24-bit dual-axis quadrature counter chips. Core functions handled by the LS7266R1, such as direction and total count, are available. Performing a write to a counter's IIO_CHAN_INFO_RAW sets the counter and also clears the counter's respective error flag. Although the counters have a 25-bit range, only the lower 24 bits may be set, either directly or via a counter's preset attribute. Interrupts are not supported by this driver. This driver adds IIO support for the ACCES 104-QUAD-8 and ACCES 104-QUAD-4. The base port addresses for the devices may be configured via the base array module parameter. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Jonathan Cameron <jic23@kernel.org>
126 lines
4.8 KiB
Plaintext
126 lines
4.8 KiB
Plaintext
What: /sys/bus/iio/devices/iio:deviceX/in_count_count_direction_available
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_count_count_mode_available
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_count_noise_error_available
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_index_index_polarity_available
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_index_synchronous_mode_available
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Discrete set of available values for the respective counter
|
|
configuration are listed in this file.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_count_direction
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Read-only attribute that indicates whether the counter for
|
|
channel Y is counting up or down.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_count_mode
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Count mode for channel Y. Four count modes are available:
|
|
normal, range limit, non-recycle, and modulo-n. The preset value
|
|
for channel Y is used by the count mode where required.
|
|
|
|
Normal:
|
|
Counting is continuous in either direction.
|
|
|
|
Range Limit:
|
|
An upper or lower limit is set, mimicking limit switches
|
|
in the mechanical counterpart. The upper limit is set to
|
|
the preset value, while the lower limit is set to 0. The
|
|
counter freezes at count = preset when counting up, and
|
|
at count = 0 when counting down. At either of these
|
|
limits, the counting is resumed only when the count
|
|
direction is reversed.
|
|
|
|
Non-recycle:
|
|
Counter is disabled whenever a 24-bit count overflow or
|
|
underflow takes place. The counter is re-enabled when a
|
|
new count value is loaded to the counter via a preset
|
|
operation or write to raw.
|
|
|
|
Modulo-N:
|
|
A count boundary is set between 0 and the preset value.
|
|
The counter is reset to 0 at count = preset when
|
|
counting up, while the counter is set to the preset
|
|
value at count = 0 when counting down; the counter does
|
|
not freeze at the bundary points, but counts
|
|
continuously throughout.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_noise_error
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Read-only attribute that indicates whether excessive noise is
|
|
present at the channel Y count inputs in quadrature clock mode;
|
|
irrelevant in non-quadrature clock mode.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_preset
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
If the counter device supports preset registers, the preset
|
|
count for channel Y is provided by this attribute.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_quadrature_mode
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Configure channel Y counter for non-quadrature or quadrature
|
|
clock mode. Selecting non-quadrature clock mode will disable
|
|
synchronous load mode. In quadrature clock mode, the channel Y
|
|
scale attribute selects the encoder phase division (scale of 1
|
|
selects full-cycle, scale of 0.5 selects half-cycle, scale of
|
|
0.25 selects quarter-cycle) processed by the channel Y counter.
|
|
|
|
Non-quadrature:
|
|
The filter and decoder circuit are bypassed. Encoder A
|
|
input serves as the count input and B as the UP/DOWN
|
|
direction control input, with B = 1 selecting UP Count
|
|
mode and B = 0 selecting Down Count mode.
|
|
|
|
Quadrature:
|
|
Encoder A and B inputs are digitally filtered and
|
|
decoded for UP/DN clock.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_countY_set_to_preset_on_index
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Whether to set channel Y counter with channel Y preset value
|
|
when channel Y index input is active, or continuously count.
|
|
Valid attribute values are boolean.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_indexY_index_polarity
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Active level of channel Y index input; irrelevant in
|
|
non-synchronous load mode.
|
|
|
|
What: /sys/bus/iio/devices/iio:deviceX/in_indexY_synchronous_mode
|
|
KernelVersion: 4.9
|
|
Contact: linux-iio@vger.kernel.org
|
|
Description:
|
|
Configure channel Y counter for non-synchronous or synchronous
|
|
load mode. Synchronous load mode cannot be selected in
|
|
non-quadrature clock mode.
|
|
|
|
Non-synchronous:
|
|
A logic low level is the active level at this index
|
|
input. The index function (as enabled via
|
|
set_to_preset_on_index) is performed directly on the
|
|
active level of the index input.
|
|
|
|
Synchronous:
|
|
Intended for interfacing with encoder Index output in
|
|
quadrature clock mode. The active level is configured
|
|
via index_polarity. The index function (as enabled via
|
|
set_to_preset_on_index) is performed synchronously with
|
|
the quadrature clock on the active level of the index
|
|
input.
|