From 06525ff87964d2e6ecc16c8e6c6d0c8c46e21e22 Mon Sep 17 00:00:00 2001
From: handsomeyingyan <handsomeyingyan@github.com>
Date: Sat, 1 May 2021 22:21:05 +0800
Subject: [PATCH 12/17] staging: loongson: fix LS2K PWM polarity

---
 drivers/staging/loongson/pwm-ls2k.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/loongson/pwm-ls2k.c b/drivers/staging/loongson/pwm-ls2k.c
index 832681470..dd0df4b4a 100644
--- a/drivers/staging/loongson/pwm-ls2k.c
+++ b/drivers/staging/loongson/pwm-ls2k.c
@@ -95,7 +95,11 @@ static int ls2k_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 		val0 = 1;
 	period = val0;
 
-	val1 = CPU_FRQ_PWM * duty_ns;
+	if (period_ns >= duty_ns)
+		val1 = CPU_FRQ_PWM * (period_ns - duty_ns);
+	else
+		val1 = 0;
+
 	do_div(val1, NSEC_PER_SEC);
 	if (val1 < 1)
 		val1 = 1;
-- 
2.17.1