Eric Lee / smarc-fsl-linux-kernel

21 Sep, 2019

2 commits

  • c91e3234c   pwm: stm32-lp: Add check in case requested period cannot be achieved ... Browse Code »

    LPTimer can use a 32KHz clock for counting. It depends on clock tree
    configuration. In such a case, PWM output frequency range is limited.
    Although unlikely, nothing prevents user from requesting a PWM frequency
    above counting clock (32KHz for instance):
    - This causes (prd - 1) = 0xffff to be written in ARR register later in
    the apply() routine.
    This results in badly configured PWM period (and also duty_cycle).
    Add a check to report an error is such a case.

    Signed-off-by: Fabrice Gasnier
    Reviewed-by: Uwe Kleine-König
    Signed-off-by: Thierry Reding

    Fabrice Gasnier
     
  • 71523d181   pwm: Ensure pwm_apply_state() doesn't modify the state argument ... Browse Code »

    It is surprising for a PWM consumer when the variable holding the
    requested state is modified by pwm_apply_state(). Consider for example a
    driver doing:

    #define PERIOD 5000000
    #define DUTY_LITTLE 10
    ...
    struct pwm_state state = {
    .period = PERIOD,
    .duty_cycle = DUTY_LITTLE,
    .polarity = PWM_POLARITY_NORMAL,
    .enabled = true,
    };

    pwm_apply_state(mypwm, &state);
    ...
    state.duty_cycle = PERIOD / 2;
    pwm_apply_state(mypwm, &state);

    For sure the second call to pwm_apply_state() should still have
    state.period = PERIOD and not something the hardware driver chose for a
    reason that doesn't necessarily apply to the second call.

    So declare the state argument as a pointer to a const type and adapt all
    drivers' .apply callbacks.

    Signed-off-by: Uwe Kleine-König
    Signed-off-by: Thierry Reding

    Uwe Kleine-König
     

25 Jun, 2019

1 commit

  • cce4a833f   pwm: stm32-lp: Add power management support ... Browse Code »

    Add suspend/resume PM sleep ops. When going to low power, enforce the PWM
    channel isn't active. Let the PWM consumers disable it during their own
    suspend sequence. Only perform a check here, and handle the pinctrl states.
    See [1].
    [1] https://lkml.org/lkml/2019/2/5/770

    Signed-off-by: Fabrice Gasnier
    Signed-off-by: Thierry Reding

    Fabrice Gasnier
     

20 Aug, 2018

1 commit

28 Mar, 2018

2 commits

15 Nov, 2017

1 commit

04 Sep, 2017

1 commit