From mboxrd@z Thu Jan 1 00:00:00 1970 From: stefan.wahren@i2se.com (Stefan Wahren) Date: Fri, 9 Feb 2018 18:01:52 +0100 (CET) Subject: [PATCH] ARM: dts: bcm2837-rpi-3-b: fix pwm1 pin In-Reply-To: <726612883.202327.1514736894033@email.1und1.de> References: <726612883.202327.1514736894033@email.1und1.de> Message-ID: <468560280.82049.1518195712847@email.1und1.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Eric, > Stefan Wahren hat am 31. Dezember 2017 um 17:14 geschrieben: > > > Hi Baruch, > > > Baruch Siach hat am 31. Dezember 2017 um 16:12 geschrieben: > > > > > > Raspberry Pi 3 uses GPIO45 for I2C SCL0. pwm1 is on GPIO41. Update the > > DT description accordingly. Fix the following error that shows when > > GPIO44 and GPIO45 are configured to I2C: > > > > [ 1.751563] pinctrl-bcm2835 3f200000.gpio: pin gpio45 already requested by 3f205000.i2c; cannot claim for 3f20c000.pwm > > [ 1.762474] pinctrl-bcm2835 3f200000.gpio: pin-45 (3f20c000.pwm) status -22 > > [ 1.775176] pinctrl-bcm2835 3f200000.gpio: could not request pin 45 (gpio45) from group gpio45 on device pinctrl-bcm2835 > > [ 1.786344] bcm2835-pwm 3f20c000.pwm: Error applying setting, reverse things back > > [ 1.793980] bcm2835-pwm: probe of 3f20c000.pwm failed with error -22 > > > > Signed-off-by: Baruch Siach > > --- > > arch/arm/boot/dts/bcm2837-rpi-3-b.dts | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/arch/arm/boot/dts/bcm2837-rpi-3-b.dts b/arch/arm/boot/dts/bcm2837-rpi-3-b.dts > > index a8844d033b3f..b44b3b5af00d 100644 > > --- a/arch/arm/boot/dts/bcm2837-rpi-3-b.dts > > +++ b/arch/arm/boot/dts/bcm2837-rpi-3-b.dts > > @@ -60,3 +60,9 @@ > > status = "okay"; > > bus-width = <4>; > > }; > > + > > +&pwm { > > + pinctrl-names = "default"; > > + pinctrl-0 = <&pwm0_gpio40 &pwm1_gpio41>; > > + status = "okay"; > > +}; > > thanks for addressing this old issue. Unfortunately this is only a part of the solution. The real problem is the definition of pinctrl in a very common dtsi file (bcm2835-rpi.dtsi). Based on the Firmware dt-blob i created a pin usage map [1], which also shows a potential conflict on RPI Zero W. > > So i think we should remove the pwm part from bcm2835-rpi.dtsi and define it on board level like in your patch, but also for the other boards. My suggestion would be the following (based on Firmware): > > A Plus -> PWM on pin 40,45 > A -> PWM on pin 40,45 > B Plus -> PWM on pin 40,45 > B Rev 2 -> PWM on pin 40,45 > B -> PWM on pin 40,45 > 2 b -> PWM on pin 40,45 > 3 b -> PWM on pin 40,41 > Zero -> No PWM > Zero W -> No PWM > > But i think we should wait for Eric's opinion. ping ... > > Regards > Stefan > > [1] - https://github.com/raspberrypi/firmware/wiki/Pin-usage-reference