arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

[PATCH] arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

Posted by Francesco Valla 3 weeks, 3 days ago

According to the HW schematic, the CAN transceiver does not have an
enable pin but a silent one. Fix the GPIO property name and polarity.

Fixes: b4bf5e55899e ("arm64: dts: freescale: Add FRDM-IMX91 basic support")

Signed-off-by: Francesco Valla <francesco@valla.it>
---
 arch/arm64/boot/dts/freescale/imx91-11x11-frdm.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/imx91-11x11-frdm.dts b/arch/arm64/boot/dts/freescale/imx91-11x11-frdm.dts
index 0d1acf8a55a5b4ac649fc8eb7c7aa2c0724b267d..c25561574d3fc5a9823f187c9d62eb9032b7ef7d 100644
--- a/arch/arm64/boot/dts/freescale/imx91-11x11-frdm.dts
+++ b/arch/arm64/boot/dts/freescale/imx91-11x11-frdm.dts
@@ -39,7 +39,7 @@ flexcan_phy: can-phy {
 		compatible = "nxp,tja1051";
 		#phy-cells = <0>;
 		max-bitrate = <5000000>;
-		enable-gpios = <&pcal6524 23 GPIO_ACTIVE_LOW>;
+		silent-gpios = <&pcal6524 23 GPIO_ACTIVE_HIGH>;
 	};
 
 	gpio-keys {

---
base-commit: 9b7977f9e39b7768c70c2aa497f04e7569fd3e00
change-id: 20260115-imx91_fix-509d4058db64

Best regards,
-- 
Francesco Valla <francesco@valla.it>

Re: [PATCH] arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

Posted by Shawn Guo 3 weeks ago

On Thu, Jan 15, 2026 at 06:41:10PM +0100, Francesco Valla wrote:
> According to the HW schematic, the CAN transceiver does not have an
> enable pin but a silent one. Fix the GPIO property name and polarity.
> 
> Fixes: b4bf5e55899e ("arm64: dts: freescale: Add FRDM-IMX91 basic support")
> 
> Signed-off-by: Francesco Valla <francesco@valla.it>

Applied, thanks!

Re: [PATCH] arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

Posted by Daniel Baluta 3 weeks, 2 days ago

On Thu, Jan 15, 2026 at 8:25 PM Francesco Valla <francesco@valla.it> wrote:
>
> According to the HW schematic, the CAN transceiver does not have an
> enable pin but a silent one. Fix the GPIO property name and polarity.
>
> Fixes: b4bf5e55899e ("arm64: dts: freescale: Add FRDM-IMX91 basic support")

Just for clarification GPIO 23 is connected to a pin named CAN_STBY.
So I wonder if it isn't
better to use standby-gpios instead of silent-gpios?

I am looking at FRDM-IMX91 schematic file SPF-94610_A1.pdf.

But on the other hand we have

static const struct can_transceiver_data tja1051_drvdata = {
»       .flags = CAN_TRANSCEIVER_SILENT_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
};

So TJA1051 is not advertised as having a stdby flag.

Re: [PATCH] arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

Posted by Francesco Valla 3 weeks, 2 days ago

Hi Daniel,

On Fri, Jan 16, 2026 at 01:40:11PM +0200, Daniel Baluta wrote:
> On Thu, Jan 15, 2026 at 8:25 PM Francesco Valla <francesco@valla.it> wrote:
> >
> > According to the HW schematic, the CAN transceiver does not have an
> > enable pin but a silent one. Fix the GPIO property name and polarity.
> >
> > Fixes: b4bf5e55899e ("arm64: dts: freescale: Add FRDM-IMX91 basic support")
> 
> Just for clarification GPIO 23 is connected to a pin named CAN_STBY.
> So I wonder if it isn't
> better to use standby-gpios instead of silent-gpios?
> 
> I am looking at FRDM-IMX91 schematic file SPF-94610_A1.pdf.
> 
> But on the other hand we have
> 
> static const struct can_transceiver_data tja1051_drvdata = {
> »       .flags = CAN_TRANSCEIVER_SILENT_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
> };
> 
> So TJA1051 is not advertised as having a stdby flag.

Regardless of the name of the net, the functionality of a standby vs a
silent pin is very different. In this case, since the TJA1051 is
including a silent pin (pin S in he datasheet [0]), I think it's better
to declare it that way.

In case someone adds the support for a phy-oriented listen-only mode
(which is something I am thinking), this wouldn't break the integartion.

Regards,
Francesco

[0] https://www.nxp.com/docs/en/data-sheet/TJA1051.pdf

Re: [PATCH] arm64: dts: imx91-11x11-frdm: fix CAN transceiver gpio

Posted by Daniel Baluta 3 weeks, 2 days ago

On Fri, Jan 16, 2026 at 3:04 PM Francesco Valla <francesco@valla.it> wrote:
>
> Hi Daniel,
>
> On Fri, Jan 16, 2026 at 01:40:11PM +0200, Daniel Baluta wrote:
> > On Thu, Jan 15, 2026 at 8:25 PM Francesco Valla <francesco@valla.it> wrote:
> > >
> > > According to the HW schematic, the CAN transceiver does not have an
> > > enable pin but a silent one. Fix the GPIO property name and polarity.
> > >
> > > Fixes: b4bf5e55899e ("arm64: dts: freescale: Add FRDM-IMX91 basic support")
> >
> > Just for clarification GPIO 23 is connected to a pin named CAN_STBY.
> > So I wonder if it isn't
> > better to use standby-gpios instead of silent-gpios?
> >
> > I am looking at FRDM-IMX91 schematic file SPF-94610_A1.pdf.
> >
> > But on the other hand we have
> >
> > static const struct can_transceiver_data tja1051_drvdata = {
> > »       .flags = CAN_TRANSCEIVER_SILENT_PRESENT | CAN_TRANSCEIVER_EN_PRESENT,
> > };
> >
> > So TJA1051 is not advertised as having a stdby flag.
>
> Regardless of the name of the net, the functionality of a standby vs a
> silent pin is very different. In this case, since the TJA1051 is
> including a silent pin (pin S in he datasheet [0]), I think it's better
> to declare it that way.
>
> In case someone adds the support for a phy-oriented listen-only mode
> (which is something I am thinking), this wouldn't break the integartion.

Makes sense.

Acked-by: Daniel Baluta <daniel.baluta@nxp.com>