st,stm32-lptim
Vendor: STMicroelectronics
Note
An implementation of a driver matching this compatible is available in drivers/timer/stm32_lptim_timer.c.
Description
STM32 lptim : low power timer
The lptim node to be used for counting ticks during lowpower modes
must be named stm32_lp_tick_source in the DTS, as follows:
stm32_lp_tick_source: &lptim1 {
status = "okay";
}
Properties
Properties not inherited from the base binding file.
Name |
Type |
Details |
|---|---|---|
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Clock divider at the input of the lptimer clock, default reset value is 'not divided'.
Prescaler allows to achieve higher LPTIM timeout (up to 256s when lptim clocked by LSE)
and consequently higher core sleep durations, but impacts the tick precision.
To be used with caution.
CONFIG_SYS_CLOCK_TICKS_PER_SEC could be used to tune tick duration and gain precision,
at kernel timing granularity cost.
For example, when LPTIM is clocked by the LSE (32768Hz) and st,prescaler = <32>:
LPTIM global timeout is 64 seconds with an increment of 0.97 ms.
Using CONFIG_SYS_CLOCK_TICKS_PER_SEC = 4096, tick = 0.24 ms, LPTIM precision is 4 ticks.
Using CONFIG_SYS_CLOCK_TICKS_PER_SEC = 1024, tick = 0.97 ms, LPTIM precision is 1 ticks.
Default value: Legal values: |
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Gives the LPTIM an exact counting value (s) for timeout expiration.
Valid range is [1, 256] and should be consistent with st,prescaler
pre-defined setting. If not, an error is raised.
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Name of each reset
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Deprecated properties not inherited from the base binding file.
(None)
Properties inherited from the base binding file, which defines common properties that may be set on many nodes. Not all of these may apply to the “st,stm32-lptim” compatible.
Name |
Type |
Details |
|---|---|---|
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register space
This property is required. See Important properties for more information. |
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Clock gate information
This property is required. |
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indicates the operational status of a device
Legal values: See Important properties for more information. |
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compatible strings
This property is required. See Important properties for more information. |
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name of each register space
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interrupts for device
See Important properties for more information. |
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extended interrupt specifier for device
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name of each interrupt
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phandle to interrupt controller node
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Human readable string describing the device (used as device_get_binding() argument)
See Important properties for more information. This property is deprecated. |
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name of each clock
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number of address cells in reg property
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number of size cells in reg property
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DMA channels specifiers
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Provided names of DMA channel specifiers
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IO channels specifiers
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Provided names of IO channel specifiers
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mailbox / IPM channels specifiers
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Provided names of mailbox / IPM channel specifiers
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Power domain specifiers
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Provided names of power domain specifiers
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Number of cells in power-domains property
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Do not initialize device automatically on boot. Device should be manually
initialized using device_init().
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Property to identify that a device can be used as wake up source.
When this property is provided a specific flag is set into the
device that tells the system that the device is capable of
wake up the system.
Wake up capable devices are disabled (interruptions will not wake up
the system) by default but they can be enabled at runtime if necessary.
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Automatically configure the device for runtime power management after the
init function runs.
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List of power states that will disable this device power.
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