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pwm: Make of_pwm_xlate_with_flags() work with #pwm-cells = <2>

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The two functions of_pwm_simple_xlate() and of_pwm_xlate_with_flags()
are quite similar. of_pwm_simple_xlate() only supports two-cell PWM
specifiers while of_pwm_xlate_with_flags() only supports PWM specifiers
with 3 or more cells. The latter can easily be modified to behave
identically to of_pwm_simple_xlate() for two-cell PWM specifiers. This
is implemented here and allows to drop of_pwm_simple_xlate() in the next
commit.

There is a small detail that is different now in the two-cell specifier
case in of_pwm_xlate_with_flags(): pwm->args.polarity is unconditionally
initialized to PWM_POLARITY_NORMAL in the latter. I didn't find a case
where this matters and doing that explicitly is the more robust
approach.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix up checkpatch warnings]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
This commit is contained in:
Uwe Kleine-König
2021-05-10 16:06:37 +02:00
committed by Thierry Reding
parent 6efb943b86
commit cf38c978cf
1 changed files with 5 additions and 4 deletions
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9
drivers/pwm/core.c
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@ -126,8 +126,7 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
{ {
struct pwm_device *pwm; struct pwm_device *pwm;
/* check, whether the driver supports a third cell for flags */ if (pc->of_pwm_n_cells < 2)
if (pc->of_pwm_n_cells < 3)
return ERR_PTR(-EINVAL); return ERR_PTR(-EINVAL);
/* flags in the third cell are optional */ /* flags in the third cell are optional */
@ -144,8 +143,10 @@ of_pwm_xlate_with_flags(struct pwm_chip *pc, const struct of_phandle_args *args)
pwm->args.period = args->args[1]; pwm->args.period = args->args[1];
pwm->args.polarity = PWM_POLARITY_NORMAL; pwm->args.polarity = PWM_POLARITY_NORMAL;
if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED) if (pc->of_pwm_n_cells >= 3) {
pwm->args.polarity = PWM_POLARITY_INVERSED; if (args->args_count > 2 && args->args[2] & PWM_POLARITY_INVERTED)
pwm->args.polarity = PWM_POLARITY_INVERSED;
}
return pwm; return pwm;
} }