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Message-ID: <8d9a6dc7-7590-412d-aa81-18a6cf5d09ca@ti.com>
Date: Tue, 16 Apr 2024 14:52:21 +0530
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Subject: Re: [PATCH] arm64: dts: ti: k3-j784s4-evm: Add support for multiple
 CAN instances
To: "Kumar, Udit" <u-kumar1@ti.com>, <linux-kernel@vger.kernel.org>,
        <devicetree@vger.kernel.org>, <vigneshr@ti.com>
CC: <linux-arm-kernel@lists.infradead.org>, <conor+dt@kernel.org>,
        <krzk+dt@kernel.org>, <robh@kernel.org>, <kristo@kernel.org>,
        <nm@ti.com>
References: <20240411201747.18697-1-b-kapoor@ti.com>
 <85ea2b33-05ac-400f-8017-5539d21ebe32@ti.com>
Content-Language: en-US
From: Bhavya Kapoor <b-kapoor@ti.com>
In-Reply-To: <85ea2b33-05ac-400f-8017-5539d21ebe32@ti.com>
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On 15/04/24 10:42, Kumar, Udit wrote:
> Hello Bhavya,
>
> On 4/12/2024 1:47 AM, Bhavya Kapoor wrote:
>> CAN instances 0 and 1 in the mcu domain and 16 in the main domain are
>> brought on the evm through headers J42, J43 and J46 respectively. Thus,
>> add their respective transceiver's 0, 1 and 2 dt nodes to add support
>> for these CAN instances.
>
> Looking at schematic and board data sheet, it appears, board has 6 CAN interfaces.
>
> [J41--J46],  but we are enabling only 4.
>
> I understand, other interfaces might be used for other purpose.
>
> Vignesh/Nishanth,
>
> Do you think, this make sense to code all available interfaces on board and
>
> mark as reserved, if used for other purpose , similar to what is done for wkup_uart for this board.
>
Hi Udit, there is a mux that is used between audio and the signal lines of other 2 cans.

If we turn on the other 2 cans or even mark  them as reserved, we will still have to

alter the mux sel lines which will impact the audio.

Thanks.

~B-Kapoor

>
>> CAN instance 4 in the main domain is brought on the evm through header
>> J45. The CAN High and Low lines from the SoC are routed through a mux
>> on the evm. The select lines need to be set for the CAN signals to
>> reach to its transceiver on the evm. Therefore, add transceiver 3
>> dt node to add support for this CAN instance.
>>
>> Signed-off-by: Bhavya Kapoor <b-kapoor@ti.com>
>> ---
>>
>> rebased to next-20240411
>>
>>   arch/arm64/boot/dts/ti/k3-j784s4-evm.dts | 107 +++++++++++++++++++++++
>>   1 file changed, 107 insertions(+)
>>
>> diff --git a/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts b/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts
>> index 81fd7afac8c5..e56901973895 100644
>> --- a/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts
>> +++ b/arch/arm64/boot/dts/ti/k3-j784s4-evm.dts
>> @@ -272,6 +272,45 @@ dp0_connector_in: endpoint {
>>               };
>>           };
>>       };
>> +
>> +    transceiver0: can-phy0 {
>> +        compatible = "ti,tcan1042";
>> +        #phy-cells = <0>;
>> +        max-bitrate = <5000000>;
>> +        pinctrl-names = "default";
>> +        pinctrl-0 = <&mcu_mcan0_gpio_pins_default>;
>> +        standby-gpios = <&wkup_gpio0 69 GPIO_ACTIVE_HIGH>;
>> +    };
>> +
>> +    transceiver1: can-phy1 {
>> +        compatible = "ti,tcan1042";
>> +        #phy-cells = <0>;
>> +        max-bitrate = <5000000>;
>> +        pinctrl-names = "default";
>> +        pinctrl-0 = <&mcu_mcan1_gpio_pins_default>;
>> +        standby-gpios = <&wkup_gpio0 2 GPIO_ACTIVE_HIGH>;
>> +    };
>> +
>> +    transceiver2: can-phy2 {
>> +        /* standby pin has been grounded by default */
>> +        compatible = "ti,tcan1042";
>> +        #phy-cells = <0>;
>> +        max-bitrate = <5000000>;
>> +    };
>> +
>> +    transceiver3: can-phy3 {
>> +        compatible = "ti,tcan1042";
>> +        #phy-cells = <0>;
>> +        max-bitrate = <5000000>;
>> +        standby-gpios = <&exp2 7 GPIO_ACTIVE_HIGH>;
>> +        mux-states = <&mux1 1>;
>> +    };
>> +
>> +    mux1: mux-controller {
>> +        compatible = "gpio-mux";
>> +        #mux-state-cells = <1>;
>> +        mux-gpios = <&exp2 14 GPIO_ACTIVE_HIGH>;
>
> Could you help here on logic to choose pin 14
>
> As I see for this mux
>
> S0 is CANUART_MUX_SEL0 [Pin 14, which you want to control as high]
>
> S1 is Pin 15 is "CANUART_MUX2_SEL1"
>
> S2 is high
>
> So in order to get CAN on mux output
>
> All, S0, S1 and S2 should be high.
>
> IMO, you should control both S0 and S1, or just S1 and S0 with dip switch

Hi Udit, S0 comes at a default Active High State always. Thus, i have kept it the same.

This was done in the same way as it was done for mux2 for  j721s2. mcan 5

Thanks

>
>> +    };
>>   };
>>     &wkup_gpio0 {
>> @@ -336,6 +375,20 @@ J784S4_IOPAD(0x014, PIN_INPUT_PULLUP, 8) /* (AG33) MCAN14_TX.I2C4_SCL */
>>               J784S4_IOPAD(0x010, PIN_INPUT_PULLUP, 8) /* (AH33) MCAN13_RX.I2C4_SDA */
>>           >;
>>       };
>> +
>> +    main_mcan4_pins_default: main-mcan4-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_IOPAD(0x088, PIN_INPUT, 0) /* (AF36) MCAN4_RX */
>> +            J784S4_IOPAD(0x084, PIN_OUTPUT, 0) /* (AG38) MCAN4_TX */
>> +        >;
>> +    };
>> +
>> +    main_mcan16_pins_default: main-mcan16-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_IOPAD(0x028, PIN_INPUT, 0) /* (AE33) MCAN16_RX */
>> +            J784S4_IOPAD(0x024, PIN_OUTPUT, 0) /* (AH34) MCAN16_TX */
>> +        >;
>> +    };
>>   };
>>     &wkup_pmx2 {
>> @@ -415,6 +468,32 @@ J784S4_WKUP_IOPAD(0x104, PIN_INPUT, 0) /* (U33) MCU_ADC1_AIN6 */
>>               J784S4_WKUP_IOPAD(0x108, PIN_INPUT, 0) /* (Y36) MCU_ADC1_AIN7 */
>>           >;
>>       };
>> +
>> +    mcu_mcan0_pins_default: mcu-mcan0-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_WKUP_IOPAD(0x050, PIN_OUTPUT, 0) /* (K33) MCU_MCAN0_TX */
>> +            J784S4_WKUP_IOPAD(0x054, PIN_INPUT, 0) /* (F38) MCU_MCAN0_RX */
>> +        >;
>> +    };
>> +
>> +    mcu_mcan1_pins_default: mcu-mcan1-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_WKUP_IOPAD(0x068, PIN_OUTPUT, 0) /* (H35) WKUP_GPIO0_4.MCU_MCAN1_TX */
>> +            J784S4_WKUP_IOPAD(0x06c, PIN_INPUT, 0) /* (K36) WKUP_GPIO0_5.MCU_MCAN1_RX */
>> +        >;
>> +    };
>> +
>> +    mcu_mcan0_gpio_pins_default: mcu-mcan0-gpio-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_WKUP_IOPAD(0x040, PIN_INPUT, 7) /* (J38) MCU_SPI0_D1.WKUP_GPIO0_69 */
>> +        >;
>> +    };
>> +
>> +    mcu_mcan1_gpio_pins_default: mcu-mcan1-gpio-default-pins {
>> +        pinctrl-single,pins = <
>> +            J784S4_WKUP_IOPAD(0x060, PIN_INPUT, 7) /* (J35) WKUP_GPIO0_2 */
>> +        >;
>> +    };
>>   };
>>     &wkup_pmx1 {
>> @@ -1105,3 +1184,31 @@ dp0_out: endpoint {
>>           };
>>       };
>>   };
>> +
>> +&mcu_mcan0 {
>> +    status = "okay";
>> +    pinctrl-names = "default";
>> +    pinctrl-0 = <&mcu_mcan0_pins_default>;
>> +    phys = <&transceiver0>;
>> +};
>> +
>> +&mcu_mcan1 {
>> +    status = "okay";
>> +    pinctrl-names = "default";
>> +    pinctrl-0 = <&mcu_mcan1_pins_default>;
>> +    phys = <&transceiver1>;
>> +};
>> +
>> +&main_mcan16 {
>> +    status = "okay";
>> +    pinctrl-names = "default";
>> +    pinctrl-0 = <&main_mcan16_pins_default>;
>> +    phys = <&transceiver2>;
>> +};
>> +
>> +&main_mcan4 {
>> +    status = "okay";
>> +    pinctrl-names = "default";
>> +    pinctrl-0 = <&main_mcan4_pins_default>;
>> +    phys = <&transceiver3>;
>> +};