pwm: meson: Explicitly set .polarity in .get_state()

stable inclusion
from stable-v5.10.179
commit b28079807de2144ca88d4f2a5cf039c58e48654d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I8C809

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b28079807de2144ca88d4f2a5cf039c58e48654d

--------------------------------

commit 8caa81eb upstream.

The driver only supports normal polarity. Complete the implementation of
.get_state() by setting .polarity accordingly.

This fixes a regression that was possible since commit c73a3107
("pwm: Handle .get_state() failures") which stopped to zero-initialize
the state passed to the .get_state() callback. This was reported at
https://forum.odroid.com/viewtopic.php?f=177&t=46360

 . While this was an
unintended side effect, the real issue is the driver's callback not
setting the polarity.

There is a complicating fact, that the .apply() callback fakes support
for inversed polarity. This is not (and cannot) be matched by
.get_state(). As fixing this isn't easy, only point it out in a comment
to prevent authors of other drivers from copying that approach.

Fixes: c375bcba ("pwm: meson: Read the full hardware state in meson_pwm_get_state()")
Reported-by: Munehisa Kamata <kamatam@amazon.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@pengutronix.de


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>