drivers: pwm: check if pulse > period and other cleanups #44583
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Calling pwm_pin_set_cycles with a pulse > period doesn't make sense. By definition, pulse ranges from 0 up to the period value. Signed-off-by: Gerard Marull-Paretas <[email protected]>
The API call checks for this condition before calling the pin_set driver OP call, so drivers don't have to do this check now. Signed-off-by: Gerard Marull-Paretas <[email protected]>
The API spec states that calling pin_set() with period set to 0 is equivalent to set the PWM channel to an inactive level. Some drivers treat this input as invalid (-EINVAL), however, it's an unsupported feature. Maybe it's due to copy&paste effect? This changes error message to be clear and changes return value to -ENOTSUP for this case. Signed-off-by: Gerard Marull-Paretas <[email protected]>
If dev was null, caller would have faulted before since dev->api needs to be accessed before reaching this point. Also, a well-defined device will never have a NULL dev->config. Signed-off-by: Gerard Marull-Paretas <[email protected]>
All these sort of helpers were removed from tree a while ago, this one was missed as it uses a custom name. Signed-off-by: Gerard Marull-Paretas <[email protected]>
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erwango
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Apr 6, 2022
anangl
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Apr 6, 2022
| @@ -193,6 +194,10 @@ static inline int z_impl_pwm_pin_set_cycles(const struct device *dev, | |||
| const struct pwm_driver_api *api = | |||
| (const struct pwm_driver_api *)dev->api; | |||
|
|
|||
| if (pulse > period) { | |||
| return -EINVAL; | |||
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Why not do pulse = period; instead?
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It's an option to clamp pulse to period value, but still, I think that a pulse > period is wrong, so it may indicate an application issue.
carlescufi
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Apr 6, 2022
MaureenHelm
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Apr 6, 2022
henrikbrixandersen
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mmahadevan108
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Calling pwm_pin_set_cycles with a pulse > period doesn't make sense. By
definition, pulse ranges from 0 up to the period value.
Also:
equivalent to set the PWM channel to an inactive level. Some drivers
treat this input as invalid (-EINVAL), however, it's an unsupported
feature. Maybe it's due to copy&paste effect? This changes error message
to be clear, and changes return value to -ENOTSUP for this case.