gpio: mvebu/pwm: Refuse requests with inverted polarity

stable inclusion
from stable-v5.10.118
commit 210ea7da5c1f72b8ef07b3b5f450db9d3e92a764
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5L686

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=210ea7da5c1f72b8ef07b3b5f450db9d3e92a764

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

[ Upstream commit 3ecb1017 ]

The driver doesn't take struct pwm_state::polarity into account when
configuring the hardware, so refuse requests for inverted polarity.

Fixes: 757642f9 ("gpio: mvebu: Add limited PWM support")
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Acked-by: NXie XiuQi <xiexiuqi@huawei.com>

drivers/gpio/gpio-mvebu.c

@@ -700,6 +700,9 @@ static int mvebu_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	unsigned long flags;
 	unsigned int on, off;
 
+	if (state->polarity != PWM_POLARITY_NORMAL)
+		return -EINVAL;
+
 	val = (unsigned long long) mvpwm->clk_rate * state->duty_cycle;
 	do_div(val, NSEC_PER_SEC);
 	if (val > UINT_MAX)