pwm: pxa: Use abrupt shutdown mode

Switch to abrupt shutdown mode in order to stop the clock as soon as
possible when PWM is disabled. This minimizes the possibility of the
clock being re-enabled while it is still in the process of turning off,
which will result in the clock ending up erroneously disabled.
Signed-off-by: Doug Brown <doug@schmorgal.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20221113233639.24244-5-doug@schmorgal.comSigned-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

drivers/pwm/pwm-pxa.c

@@ -85,7 +85,7 @@ static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 	else
 		dc = mul_u64_u64_div_u64(pv + 1, duty_ns, period_ns);
 
-	writel(prescale, pc->mmio_base + offset + PWMCR);
+	writel(prescale | PWMCR_SD, pc->mmio_base + offset + PWMCR);
 	writel(dc, pc->mmio_base + offset + PWMDCR);
 	writel(pv, pc->mmio_base + offset + PWMPCR);