linux/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
Benjamin Gaignard 2a830a45ff iio: stm32 trigger: Add counter enable modes
Device counting could be controlled by the level or the edges of
a trigger.
in_count0_enable_mode attibute allow to set the control mode.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-04-14 15:09:04 +01:00

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What: /sys/bus/iio/devices/triggerX/master_mode_available
KernelVersion: 4.11
Contact: benjamin.gaignard@st.com
Description:
Reading returns the list possible master modes which are:
- "reset" : The UG bit from the TIMx_EGR register is
used as trigger output (TRGO).
- "enable" : The Counter Enable signal CNT_EN is used
as trigger output.
- "update" : The update event is selected as trigger output.
For instance a master timer can then be used
as a prescaler for a slave timer.
- "compare_pulse" : The trigger output send a positive pulse
when the CC1IF flag is to be set.
- "OC1REF" : OC1REF signal is used as trigger output.
- "OC2REF" : OC2REF signal is used as trigger output.
- "OC3REF" : OC3REF signal is used as trigger output.
- "OC4REF" : OC4REF signal is used as trigger output.
What: /sys/bus/iio/devices/triggerX/master_mode
KernelVersion: 4.11
Contact: benjamin.gaignard@st.com
Description:
Reading returns the current master modes.
Writing set the master mode
What: /sys/bus/iio/devices/triggerX/sampling_frequency
KernelVersion: 4.11
Contact: benjamin.gaignard@st.com
Description:
Reading returns the current sampling frequency.
Writing an value different of 0 set and start sampling.
Writing 0 stop sampling.
What: /sys/bus/iio/devices/iio:deviceX/in_count0_preset
KernelVersion: 4.12
Contact: benjamin.gaignard@st.com
Description:
Reading returns the current preset value.
Writing sets the preset value.
When counting up the counter starts from 0 and fires an
event when reach preset value.
When counting down the counter start from preset value
and fire event when reach 0.
What: /sys/bus/iio/devices/iio:deviceX/in_count_quadrature_mode_available
KernelVersion: 4.12
Contact: benjamin.gaignard@st.com
Description:
Reading returns the list possible quadrature modes.
What: /sys/bus/iio/devices/iio:deviceX/in_count0_quadrature_mode
KernelVersion: 4.12
Contact: benjamin.gaignard@st.com
Description:
Configure the device counter quadrature modes:
channel_A:
Encoder A input servers as the count input and B as
the UP/DOWN direction control input.
channel_B:
Encoder B input serves as the count input and A as
the UP/DOWN direction control input.
quadrature:
Encoder A and B inputs are mixed to get direction
and count with a scale of 0.25.
What: /sys/bus/iio/devices/iio:deviceX/in_count_enable_mode_available
KernelVersion: 4.12
Contact: benjamin.gaignard@st.com
Description:
Reading returns the list possible enable modes.
What: /sys/bus/iio/devices/iio:deviceX/in_count0_enable_mode
KernelVersion: 4.12
Contact: benjamin.gaignard@st.com
Description:
Configure the device counter enable modes, in all case
counting direction is set by in_count0_count_direction
attribute and the counter is clocked by the internal clock.
always:
Counter is always ON.
gated:
Counting is enabled when connected trigger signal
level is high else counting is disabled.
triggered:
Counting is enabled on rising edge of the connected
trigger, and remains enabled for the duration of this
selected mode.