LPIT Support on Zephyr #93167
LPIT Support on Zephyr #93167
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FelixWang47831
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Jul 16, 2025
FelixWang47831
commented
- Provide counter driver based on lpit driver from NXP mcux-sdk-ng
- Enable tests/drivers/counter/counter_nxp_lpit_api based on NXP mimxrt1180_evk, all channels test pass.
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Hello @FelixWang47831, and thank you very much for your first pull request to the Zephyr project! |
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added
area: Counter
platform: NXP Drivers
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drivers/counter/counter_mcux_lpit.c
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| static int mcux_lpit_start(const struct device *dev) | ||
| { | ||
| const struct mcux_lpit_config *config = dev->config; | ||
| uint8_t channel_id = LPIT_CHANNEL_ID(dev); | ||
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| LOG_DBG("period is %d", mcux_lpit_get_top_value(dev)); | ||
| LPIT_EnableInterrupts(config->base, (1U << channel_id)); | ||
| LPIT_StartTimer(config->base, channel_id); | ||
| return 0; | ||
| } | ||
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| static int mcux_lpit_stop(const struct device *dev) | ||
| { | ||
| const struct mcux_lpit_config *config = dev->config; | ||
| int channel_id = LPIT_CHANNEL_ID(dev); | ||
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| LPIT_DisableInterrupts(config->base, (1U << channel_id)); | ||
| LPIT_StopTimer(config->base, channel_id); | ||
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| return 0; | ||
| } |
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is it possible to call these functions throughout various other parts of the driver where it is doing the same thing to save code size?
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Has removed "LPIT_DisableInterrupts" from mcux_lpit_stop, it's unnecessary after stop timer.
However, LPIT_EnableInterrupts in mcux_lpit_start is necessary, there is test which start counter and set top value, verify whether top callback is executed in interrupt. I have never seen enable interrupt in set top value function among all vendor's driver, so I need to enable interrupt when starting timer.
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it's not clear to me at all why are you adding this test, the test looks at a glance almost exactly the same copy pasted as the generic counter_api test already in tree, and the commit message is empty here, and there is no comment with any description about the purpose of this
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Has updated commit log to explain why adding this test:
This test is modified from tests/drivers/counter/counter_basic_api/src/
test_counter.c
The original test does not work for LPIT. For example, the hard code
channel 0 for counter_set_channel_alarm setting brings error for
lpit1_channel1, lpit2_channel3 and so on. And the setting alarm_cfgs.flags=0,
which means setting the relative ticks based on current ticks, brings
overflow errors, because LPIT is a count down timer which starts from top value.
Based on these limitation, In order to avoid modifying the original test
and bringing possible side effects to other platforms, a modified new
test was prepared here. In this test, COUNTER_ALARM_CFG_ABSOLUTE is set
for counter, and all channels specified in edvicetree file are test.
This test inclduing following tests:
- test_all_channels
- test_cancelled_alarm_does_not_expire
- test_set_top_value_with_alarm
- test_single_shot_alarm_notop
- test_single_shot_alarm_top
- test_valid_function_without_alarm
- test_set_top_value_without_alarm
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PetervdPerk-NXP
1.Add dts bindings nxp,lpit-channel.yaml and nxp,lpit.yaml 2.Provide counter driver based on lpit driver from NXP mcux-sdk-ng Signed-off-by: Felix Wang <fei.wang_3@nxp.com>
Add lpit1, lpit2, lpit3 and all of the channels information Signed-off-by: Felix Wang <fei.wang_3@nxp.com>
1. Configure clock source for lpit3 for imxrt118x devices 2. Support lpit in clock driver Signed-off-by: Felix Wang <fei.wang_3@nxp.com>
…on mimxrt1180_evk This test is modified from tests/drivers/counter/counter_basic_api/src/ test_counter.c The original test does not work for LPIT. For example, the hard code channel 0 for counter_set_channel_alarm setting brings error for lpit1_channel1, lpit2_channel3 and so on. And the setting alarm_cfgs.flags=0, which means setting the relative ticks based on current ticks, brings overflow errors, because LPIT is a count down timer which starts from top value. Based on these limitation, In order to avoid modifying the original test and bringing possible side effects to other platforms, a modified new test was prepared here. In this test, COUNTER_ALARM_CFG_ABSOLUTE is set for counter, and all channels specified in edvicetree file are test. This test inclduing following tests: - test_all_channels - test_cancelled_alarm_does_not_expire - test_set_top_value_with_alarm - test_single_shot_alarm_notop - test_single_shot_alarm_top - test_valid_function_without_alarm - test_set_top_value_without_alarm Signed-off-by: Felix Wang <fei.wang_3@nxp.com>
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