41a7d6718b
We can't duplicate the description of sampling_frequency. This device has some unusual requirements which we solved by giving a sampling_frequency of 0 special meaning. As such add a note about this unusual usage to the main documentation. Whilst I don't particularly like this resolution, it is the best I could come up with given earlier discussion on this topic. Link: https://lore.kernel.org/linux-iio/20210315101217.00002c50@Huawei.com/ Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Fabrice Gasnier <fabrice.gasnier@foss.st.com> Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org> Link: https://lore.kernel.org/r/20220626165511.602202-4-jic23@kernel.org
144 lines
4.5 KiB
Plaintext
144 lines
4.5 KiB
Plaintext
What: /sys/bus/iio/devices/triggerX/master_mode_available
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KernelVersion: 4.11
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Contact: benjamin.gaignard@st.com
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Description:
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Reading returns the list possible master modes which are:
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- "reset"
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The UG bit from the TIMx_EGR register is
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used as trigger output (TRGO).
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- "enable"
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The Counter Enable signal CNT_EN is used
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as trigger output.
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- "update"
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The update event is selected as trigger output.
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For instance a master timer can then be used
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as a prescaler for a slave timer.
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- "compare_pulse"
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The trigger output send a positive pulse
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when the CC1IF flag is to be set.
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- "OC1REF"
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OC1REF signal is used as trigger output.
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- "OC2REF"
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OC2REF signal is used as trigger output.
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- "OC3REF"
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OC3REF signal is used as trigger output.
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- "OC4REF"
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OC4REF signal is used as trigger output.
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Additional modes (on TRGO2 only):
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- "OC5REF"
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OC5REF signal is used as trigger output.
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- "OC6REF"
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OC6REF signal is used as trigger output.
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- "compare_pulse_OC4REF":
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OC4REF rising or falling edges generate pulses.
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- "compare_pulse_OC6REF":
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OC6REF rising or falling edges generate pulses.
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- "compare_pulse_OC4REF_r_or_OC6REF_r":
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OC4REF or OC6REF rising edges generate pulses.
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- "compare_pulse_OC4REF_r_or_OC6REF_f":
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OC4REF rising or OC6REF falling edges generate
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pulses.
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- "compare_pulse_OC5REF_r_or_OC6REF_r":
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OC5REF or OC6REF rising edges generate pulses.
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- "compare_pulse_OC5REF_r_or_OC6REF_f":
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OC5REF rising or OC6REF falling edges generate
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pulses.
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::
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+-----------+ +-------------+ +---------+
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| Prescaler +-> | Counter | +-> | Master | TRGO(2)
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+-----------+ +--+--------+-+ |-> | Control +-->
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| | || +---------+
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+--v--------+-+ OCxREF || +---------+
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| Chx compare +----------> | Output | ChX
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+-----------+-+ | | Control +-->
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. | | +---------+
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. | | .
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+-----------v-+ OC6REF | .
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| Ch6 compare +---------+>
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+-------------+
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Example with: "compare_pulse_OC4REF_r_or_OC6REF_r"::
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X
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X X
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X . . X
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X . . X
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X . . X
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count X . . . . X
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. . . .
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. . . .
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+---------------+
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OC4REF | . . |
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+-+ . . +-+
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. +---+ .
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OC6REF . | | .
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+-------+ +-------+
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+-+ +-+
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TRGO2 | | | |
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+-+ +---+ +---------+
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What: /sys/bus/iio/devices/triggerX/master_mode
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KernelVersion: 4.11
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Contact: benjamin.gaignard@st.com
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Description:
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Reading returns the current master modes.
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Writing set the master mode
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What: /sys/bus/iio/devices/iio:deviceX/in_count0_preset
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KernelVersion: 4.12
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Contact: benjamin.gaignard@st.com
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Description:
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Reading returns the current preset value.
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Writing sets the preset value.
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When counting up the counter starts from 0 and fires an
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event when reach preset value.
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When counting down the counter start from preset value
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and fire event when reach 0.
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What: /sys/bus/iio/devices/iio:deviceX/in_count_enable_mode_available
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KernelVersion: 4.12
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Contact: benjamin.gaignard@st.com
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Description:
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Reading returns the list possible enable modes.
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What: /sys/bus/iio/devices/iio:deviceX/in_count0_enable_mode
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KernelVersion: 4.12
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Contact: benjamin.gaignard@st.com
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Description:
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Configure the device counter enable modes, in all case
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counting direction is set by in_count0_count_direction
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attribute and the counter is clocked by the internal clock.
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always:
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Counter is always ON.
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gated:
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Counting is enabled when connected trigger signal
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level is high else counting is disabled.
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triggered:
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Counting is enabled on rising edge of the connected
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trigger, and remains enabled for the duration of this
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selected mode.
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What: /sys/bus/iio/devices/iio:deviceX/in_count_trigger_mode_available
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KernelVersion: 4.13
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Contact: benjamin.gaignard@st.com
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Description:
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Reading returns the list possible trigger modes.
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What: /sys/bus/iio/devices/iio:deviceX/in_count0_trigger_mode
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KernelVersion: 4.13
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Contact: benjamin.gaignard@st.com
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Description:
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Configure the device counter trigger mode
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counting direction is set by in_count0_count_direction
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attribute and the counter is clocked by the connected trigger
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rising edges.
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