[PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
dual high-speed CAN transceiver with sleep-mode support and no EN pin,
mirroring the behaviour of the NXP TJA1048, which also provides dual
channels and STB1/2 sleep-control lines.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf

v1->v2:
- Used "nxp,tja1048" as a fallback compatible string.
---
 Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
index c686d06f5f56..9f5c37ca6496 100644
--- a/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
+++ b/Documentation/devicetree/bindings/phy/ti,tcan104x-can.yaml
@@ -20,6 +20,9 @@ properties:
               - microchip,ata6561
               - ti,tcan1051
           - const: ti,tcan1042
+      - items:
+          - const: ti,tcan1046
+          - const: nxp,tja1048
       - enum:
           - ti,tcan1042
           - ti,tcan1043
-- 
2.52.0

Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Marc Kleine-Budde]

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On 09.12.2025 16:21:19, Prabhakar wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> mirroring the behaviour of the NXP TJA1048, which also provides dual
> channels and STB1/2 sleep-control lines.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
> TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf

The polarity of the standby line of the chips is different.

You must set the correct active high/low property for the GPIO, as the
driver uses logical levels.

Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Conor Dooley]

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On Wed, Dec 10, 2025 at 08:52:58AM +0100, Marc Kleine-Budde wrote:
> On 09.12.2025 16:21:19, Prabhakar wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> >
> > Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> > dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> > mirroring the behaviour of the NXP TJA1048, which also provides dual
> > channels and STB1/2 sleep-control lines.
> >
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > ---
> > TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> > NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf
> 
> The polarity of the standby line of the chips is different.
> 
> You must set the correct active high/low property for the GPIO, as the
> driver uses logical levels.
> 
> Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>

What you're saying seems to contradict the tag you've given, is a
fallback really suitable if the standby polarity is not the same?

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Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Lad, Prabhakar]

Hi Conor,

On Wed, Dec 10, 2025 at 6:21 PM Conor Dooley <conor@kernel.org> wrote:
>
> On Wed, Dec 10, 2025 at 08:52:58AM +0100, Marc Kleine-Budde wrote:
> > On 09.12.2025 16:21:19, Prabhakar wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> > > dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> > > mirroring the behaviour of the NXP TJA1048, which also provides dual
> > > channels and STB1/2 sleep-control lines.
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > > TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> > > NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf
> >
> > The polarity of the standby line of the chips is different.
> >
> > You must set the correct active high/low property for the GPIO, as the
> > driver uses logical levels.
> >
> > Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
>
> What you're saying seems to contradict the tag you've given, is a
> fallback really suitable if the standby polarity is not the same?
>
On the RZ/V2H I have,

    can_phy: can-phy {
        compatible = "ti,tcan1046", "nxp,tja1048";
        max-bitrate = <8000000>;
        #phy-cells = <1>;
        status = "okay";
        standby-gpios = <&pinctrl RZV2H_GPIO(7, 0) GPIO_ACTIVE_HIGH>,
                                  <&pinctrl RZV2H_GPIO(7, 2) GPIO_ACTIVE_HIGH>;
    };

When the CAN interface is brought up 0 is written to GPIO which brings
the CAN transceiver to Normal mode  and when the CAN chip is brought
down `1` is written to GPIO and it puts the CAN transceiver to Standby
mode. Which matches to the behaviour of TCAN1046 CAN transceiver. Am I
missing something?

Cheers,
Prabhakar

Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Marc Kleine-Budde]

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On 10.12.2025 18:21:34, Conor Dooley wrote:
> On Wed, Dec 10, 2025 at 08:52:58AM +0100, Marc Kleine-Budde wrote:
> > On 09.12.2025 16:21:19, Prabhakar wrote:
> > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > >
> > > Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> > > dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> > > mirroring the behaviour of the NXP TJA1048, which also provides dual
> > > channels and STB1/2 sleep-control lines.
> > >
> > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > ---
> > > TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> > > NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf
> >
> > The polarity of the standby line of the chips is different.
> >
> > You must set the correct active high/low property for the GPIO, as the
> > driver uses logical levels.
> >
> > Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
>
> What you're saying seems to contradict the tag you've given, is a
> fallback really suitable if the standby polarity is not the same?

The driver uses _logical_ levels to switch the GPIOs. For example to
power on the PHY, it disables the standby GPIO by setting the value to
"0".

| static int can_transceiver_phy_power_on(struct phy *phy)
| {
[...]
|         gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
[...]
| }

You have to use GPIO_ACTIVE_HIGH/GPIO_ACTIVE_LOW in the DT to configure
the actual level of the GPIO.

If you connect the PHY's standby input directly to the SoC's GPIO....

| TJA1048: HIGH = Normal mode, LOW = Standby mode
| TCAN1046: High = Standby mode, Low = Normal Mode

...for the TJA1048 you would use GPIO_ACTIVE_LOW, while for the
TCAN1046 you would use GPIO_ACTIVE_HIGH.

regards,
Marc

-- 
Pengutronix e.K.                 | Marc Kleine-Budde          |
Embedded Linux                   | https://www.pengutronix.de |
Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |

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Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Conor Dooley]

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On Fri, Dec 12, 2025 at 12:21:03PM +0100, Marc Kleine-Budde wrote:
> On 10.12.2025 18:21:34, Conor Dooley wrote:
> > On Wed, Dec 10, 2025 at 08:52:58AM +0100, Marc Kleine-Budde wrote:
> > > On 09.12.2025 16:21:19, Prabhakar wrote:
> > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > >
> > > > Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> > > > dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> > > > mirroring the behaviour of the NXP TJA1048, which also provides dual
> > > > channels and STB1/2 sleep-control lines.
> > > >
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > ---
> > > > TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> > > > NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf
> > >
> > > The polarity of the standby line of the chips is different.
> > >
> > > You must set the correct active high/low property for the GPIO, as the
> > > driver uses logical levels.
> > >
> > > Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
> >
> > What you're saying seems to contradict the tag you've given, is a
> > fallback really suitable if the standby polarity is not the same?
> 
> The driver uses _logical_ levels to switch the GPIOs. For example to
> power on the PHY, it disables the standby GPIO by setting the value to
> "0".
> 
> | static int can_transceiver_phy_power_on(struct phy *phy)
> | {
> [...]
> |         gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
> [...]
> | }
> 
> You have to use GPIO_ACTIVE_HIGH/GPIO_ACTIVE_LOW in the DT to configure
> the actual level of the GPIO.

Ah okay, I prob should have looked a bit further into the binding.
Acked-by: Conor Dooley <conor.dooley@microchip.com>


> 
> If you connect the PHY's standby input directly to the SoC's GPIO....
> 
> | TJA1048: HIGH = Normal mode, LOW = Standby mode
> | TCAN1046: High = Standby mode, Low = Normal Mode
> 
> ...for the TJA1048 you would use GPIO_ACTIVE_LOW, while for the
> TCAN1046 you would use GPIO_ACTIVE_HIGH.
> 
> regards,
> Marc
> 
> -- 
> Pengutronix e.K.                 | Marc Kleine-Budde          |
> Embedded Linux                   | https://www.pengutronix.de |
> Vertretung Nürnberg              | Phone: +49-5121-206917-129 |
> Amtsgericht Hildesheim, HRA 2686 | Fax:   +49-5121-206917-9   |



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Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Geert Uytterhoeven]

On Fri, 12 Dec 2025 at 12:22, Marc Kleine-Budde <mkl@pengutronix.de> wrote:
> On 10.12.2025 18:21:34, Conor Dooley wrote:
> > On Wed, Dec 10, 2025 at 08:52:58AM +0100, Marc Kleine-Budde wrote:
> > > On 09.12.2025 16:21:19, Prabhakar wrote:
> > > > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > >
> > > > Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> > > > dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> > > > mirroring the behaviour of the NXP TJA1048, which also provides dual
> > > > channels and STB1/2 sleep-control lines.
> > > >
> > > > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> > > > ---
> > > > TCAN 1046, https://www.ti.com/lit/ds/symlink/tcan1046v-q1.pdf?ts=1765297159307&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTCAN1046V-Q1
> > > > NXP TJA1048, https://www.nxp.com/docs/en/data-sheet/TJA1048.pdf
> > >
> > > The polarity of the standby line of the chips is different.
> > >
> > > You must set the correct active high/low property for the GPIO, as the
> > > driver uses logical levels.
> > >
> > > Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
> >
> > What you're saying seems to contradict the tag you've given, is a
> > fallback really suitable if the standby polarity is not the same?
>
> The driver uses _logical_ levels to switch the GPIOs. For example to
> power on the PHY, it disables the standby GPIO by setting the value to
> "0".
>
> | static int can_transceiver_phy_power_on(struct phy *phy)
> | {
> [...]
> |         gpiod_set_value_cansleep(can_transceiver_phy->standby_gpio, 0);
> [...]
> | }
>
> You have to use GPIO_ACTIVE_HIGH/GPIO_ACTIVE_LOW in the DT to configure
> the actual level of the GPIO.
>
> If you connect the PHY's standby input directly to the SoC's GPIO....
>
> | TJA1048: HIGH = Normal mode, LOW = Standby mode
> | TCAN1046: High = Standby mode, Low = Normal Mode
>
> ...for the TJA1048 you would use GPIO_ACTIVE_LOW, while for the
> TCAN1046 you would use GPIO_ACTIVE_HIGH.

Exactly.  For most of these CAN transceivers, there are typically two
almost identical parts (usually differing in the last digit of the part
number), one with active-high standby, another with active-low standby.
These differences can be handled perfectly fine using the GPIO_ACTIVE_*
lags.

Note that there can be other differences: the RZ/V2H board Prabhakar
works on actually has TCAN1046V.  The "V" variant differs from TCAN1046
(and TJA1048) in configuration of the two power supply pins:
  - TCAN1046 has independent supplies for the two channels,
  - TCAN1046V has separate logic and I/O supplies for the combined
    channels.
Since this difference can be handled through *-supply properties
(when the need arises, and the driver gains regulator support),
I don't think separate compatible values are needed for "V" variants.

BTW, how do I know? Because I had started working on adding support
for TCAN1046V myself, but Prabhakar beat me to sending out patches ;-)

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

Re: [PATCH v2] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046

[Vinod Koul]

On Tue, 09 Dec 2025 16:21:19 +0000, Prabhakar wrote:
> Document the TI TCAN1046 automotive CAN transceiver. The TCAN1046 is a
> dual high-speed CAN transceiver with sleep-mode support and no EN pin,
> mirroring the behaviour of the NXP TJA1048, which also provides dual
> channels and STB1/2 sleep-control lines.
> 
> 

Applied, thanks!

[1/1] dt-bindings: phy: ti,tcan104x-can: Document TI TCAN1046
      commit: 5442f9fd8814932e42602670bd013fcbc10a6906

Best regards,
-- 
~Vinod