From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Tue, 20 Apr 2021 09:51:17 +0000 (+0200)
Subject: pwm: atmel: Fix duty cycle calculation in .get_state()
X-Git-Tag: v5.11.22~163
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8a6f204ac8413c9a9760e5c249885a256e6df44f;p=thirdparty%2Fkernel%2Fstable.git

pwm: atmel: Fix duty cycle calculation in .get_state()

[ Upstream commit 453e8b3d8e36ddcb283b3d1698864a03ea45599a ]

The CDTY register contains the number of inactive cycles. .apply() does
this correctly, however .get_state() got this wrong.

Fixes: 651b510a74d4 ("pwm: atmel: Implement .get_state()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index 5813339b597b9..3292158157b68 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -319,7 +319,7 @@ static void atmel_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 
 		cdty = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm,
 					  atmel_pwm->data->regs.duty);
-		tmp = (u64)cdty * NSEC_PER_SEC;
+		tmp = (u64)(cprd - cdty) * NSEC_PER_SEC;
 		tmp <<= pres;
 		state->duty_cycle = DIV64_U64_ROUND_UP(tmp, rate);