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From: Heiner Kallweit <hkallweit1@gmail.com>
To: "Jerome Brunet" <jbrunet@baylibre.com>,
	"Martin Blumenstingl" <martin.blumenstingl@googlemail.com>,
	"Neil Armstrong" <narmstrong@baylibre.com>,
	"Kevin Hilman" <khilman@baylibre.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"thierry.reding@gmail.com" <thierry.reding@gmail.com>
Cc: "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"open list:ARM/Amlogic Meson..."
	<linux-amlogic@lists.infradead.org>,
	linux-pwm@vger.kernel.org,
	Dmitry Rokosov <ddrokosov@sberdevices.ru>
Subject: [PATCH v3] pwm: meson: modify and simplify calculation in meson_pwm_get_state
Date: Tue, 2 May 2023 22:33:42 +0200	[thread overview]
Message-ID: <23fe625e-dc23-4db8-3dce-83167cd3b206@gmail.com> (raw)

I don't see a reason why we should treat the case lo < hi differently
and return 0 as period and duty_cycle. The current logic was added with
c375bcbaabdb ("pwm: meson: Read the full hardware state in
meson_pwm_get_state()"), Martin as original author doesn't remember why
it was implemented this way back then.
So let's handle it as normal use case and also remove the optimization
for lo == 0. I think the improved readability is worth it.

Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()")
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
v2:
- improve commit description
v3:
- make patch a fix
---
 drivers/pwm/pwm-meson.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
index 5732300eb..3865538dd 100644
--- a/drivers/pwm/pwm-meson.c
+++ b/drivers/pwm/pwm-meson.c
@@ -351,18 +351,8 @@ static int meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
 	channel->lo = FIELD_GET(PWM_LOW_MASK, value);
 	channel->hi = FIELD_GET(PWM_HIGH_MASK, value);
 
-	if (channel->lo == 0) {
-		state->period = meson_pwm_cnt_to_ns(chip, pwm, channel->hi);
-		state->duty_cycle = state->period;
-	} else if (channel->lo >= channel->hi) {
-		state->period = meson_pwm_cnt_to_ns(chip, pwm,
-						    channel->lo + channel->hi);
-		state->duty_cycle = meson_pwm_cnt_to_ns(chip, pwm,
-							channel->hi);
-	} else {
-		state->period = 0;
-		state->duty_cycle = 0;
-	}
+	state->period = meson_pwm_cnt_to_ns(chip, pwm, channel->lo + channel->hi);
+	state->duty_cycle = meson_pwm_cnt_to_ns(chip, pwm, channel->hi);
 
 	state->polarity = PWM_POLARITY_NORMAL;
 
-- 
2.40.0

             reply	other threads:[~2023-05-02 20:33 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-02 20:33 Heiner Kallweit [this message]
2023-05-08 19:44 ` [PATCH v3] pwm: meson: modify and simplify calculation in meson_pwm_get_state Martin Blumenstingl
2023-05-11 14:34 ` Dmitry Rokosov

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