linux-pwm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Baruch Siach <baruch@tkos.co.il>
To: "Thierry Reding" <thierry.reding@gmail.com>,
	"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
	"Lee Jones" <lee.jones@linaro.org>,
	"Linus Walleij" <linus.walleij@linaro.org>,
	"Bartosz Golaszewski" <bgolaszewski@baylibre.com>
Cc: Baruch Siach <baruch@tkos.co.il>, Andrew Lunn <andrew@lunn.ch>,
	Gregory Clement <gregory.clement@bootlin.com>,
	Russell King <linux@armlinux.org.uk>,
	Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
	Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
	Chris Packham <chris.packham@alliedtelesis.co.nz>,
	Sascha Hauer <s.hauer@pengutronix.de>,
	Ralph Sennhauser <ralph.sennhauser@gmail.com>,
	linux-pwm@vger.kernel.org, linux-gpio@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v3 3/5] gpio: mvebu: make pwm .get_state closer to idempotent
Date: Thu, 14 Jan 2021 20:57:35 +0200	[thread overview]
Message-ID: <fdd4d425f450658ab9fc130e511fbb1bc9c3b249.1610628807.git.baruch@tkos.co.il> (raw)
In-Reply-To: <cover.1610628807.git.baruch@tkos.co.il>

Round up the divisions in .get_state() to make applying the read out
configuration idempotent in most cases as .apply rounds down.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
 drivers/gpio/gpio-mvebu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-mvebu.c b/drivers/gpio/gpio-mvebu.c
index c424d88e9e2b..8673ba77af5a 100644
--- a/drivers/gpio/gpio-mvebu.c
+++ b/drivers/gpio/gpio-mvebu.c
@@ -668,7 +668,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip,
 
 	regmap_read(mvpwm->regs, mvebu_pwmreg_blink_on_duration(mvpwm), &u);
 	val = (unsigned long long) u * NSEC_PER_SEC;
-	do_div(val, mvpwm->clk_rate);
+	val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
 	if (val > UINT_MAX)
 		state->duty_cycle = UINT_MAX;
 	else if (val)
@@ -680,7 +680,7 @@ static void mvebu_pwm_get_state(struct pwm_chip *chip,
 	regmap_read(mvpwm->regs, mvebu_pwmreg_blink_off_duration(mvpwm), &u);
 	val += (unsigned long long) u; /* period = on + off duration */
 	val *= NSEC_PER_SEC;
-	do_div(val, mvpwm->clk_rate);
+	val = DIV_ROUND_UP_ULL(val, mvpwm->clk_rate);
 	if (val > UINT_MAX)
 		state->period = UINT_MAX;
 	else if (val)
-- 
2.29.2


  parent reply	other threads:[~2021-01-14 18:58 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-14 18:57 [PATCH v3 0/5] gpio: mvebu: pwm fixes and improvements Baruch Siach
2021-01-14 18:57 ` [PATCH v3 1/5] gpio: mvebu: fix pwm .get_state period calculation Baruch Siach
2021-01-14 18:57 ` [PATCH v3 2/5] gpio: mvebu: improve pwm period calculation accuracy Baruch Siach
2021-01-14 18:57 ` Baruch Siach [this message]
2021-01-14 18:57 ` [PATCH v3 4/5] gpio: mvebu: don't limit pwm period/duty_cycle to UINT_MAX Baruch Siach
2021-01-14 18:57 ` [PATCH v3 5/5] gpio: mvebu: document zero pwm duty cycle limitation Baruch Siach
2021-01-14 20:25   ` Uwe Kleine-König
2021-01-14 22:28     ` Russell King - ARM Linux admin
2021-01-15 10:53       ` Uwe Kleine-König

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=fdd4d425f450658ab9fc130e511fbb1bc9c3b249.1610628807.git.baruch@tkos.co.il \
    --to=baruch@tkos.co.il \
    --cc=andrew@lunn.ch \
    --cc=bgolaszewski@baylibre.com \
    --cc=chris.packham@alliedtelesis.co.nz \
    --cc=gregory.clement@bootlin.com \
    --cc=lee.jones@linaro.org \
    --cc=linus.walleij@linaro.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-gpio@vger.kernel.org \
    --cc=linux-pwm@vger.kernel.org \
    --cc=linux@armlinux.org.uk \
    --cc=ralph.sennhauser@gmail.com \
    --cc=s.hauer@pengutronix.de \
    --cc=sebastian.hesselbarth@gmail.com \
    --cc=thierry.reding@gmail.com \
    --cc=thomas.petazzoni@bootlin.com \
    --cc=u.kleine-koenig@pengutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).