From: Pascal Roeleven <dev@pascalroeleven.nl>
To: "Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Maxime Ripard" <mripard@kernel.org>,
"Chen-Yu Tsai" <wens@csie.org>,
"Philipp Zabel" <p.zabel@pengutronix.de>,
linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: linux-sunxi@googlegroups.com
Subject: pwm: sun4i: pwm-backlight not working since 5.6-rc1
Date: Thu, 12 Mar 2020 13:22:13 +0100 [thread overview]
Message-ID: <6185b5540ca082d887d7d13330c9d938@pascalroeleven.nl> (raw)
Hi all,
I am working on adding an old A10 device to mainline and noticed an
issue when testing on 5.5.8 vs master.
Since 5.6-rc1, I can't control the brightness of my LCD backlight
anymore. The backlight stays on full brightness instead. I am
controlling the brightness value via sysfs for testing.
I am not sure if this is a general pwm-sun4i issue or if it is related
to the backlight. However I narrowed it down to one commit for
pwm-sun4i:
fa4d81784681a26bcf7d2a43c6ac5cf991ef28f5
If I use pwm-sun4i.c from 5b090b430d750961305030232314b6acdb0102aa on
master, the backlight works fine. Unfortunately, due to my lack of
kernel experience, I can't see how the commit above broke it.
Not sure if it helps, but the binding for the backlight is as follows:
backlight: backlight {
compatible = "pwm-backlight";
pwms = <&pwm 0 100000 PWM_POLARITY_INVERTED>;
power-supply = <®_vbat>;
enable-gpios = <&pio 7 7 GPIO_ACTIVE_HIGH>; /* PH7 */
brightness-levels = <0 30 40 50 60 70 80 90 100>;
default-brightness-level = <8>;
};
Please let me know if there is anything else which might be helpful to
know or anything I can test.
Regards,
Pascal
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next reply other threads:[~2020-03-12 12:22 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-12 12:22 Pascal Roeleven [this message]
2020-03-12 13:29 ` pwm: sun4i: pwm-backlight not working since 5.6-rc1 Uwe Kleine-König
2020-03-12 15:06 ` Pascal Roeleven
2020-03-16 7:26 ` Uwe Kleine-König
2020-03-17 17:32 ` Uwe Kleine-König
2020-03-17 17:52 ` Pascal Roeleven
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