Pinmux for CAN0_STBY (E17 )

Robotics & Edge Computing Jetson & Embedded Systems Jetson TX2
1

Dear all,

As I checked in pinmux excel sheet file, there was no any pinmux for CAN0_STBY (E17). So I’m wondering is it possible to control CAN0_STBY pin due to I want to use 2 CAN interfaces on TX2.

Thanks and Best Reagards,
Vu Nguyen

2

Hi Vu Nguyen,

I guess, it can still be configured dynamically using reg_dump tool.
You need to know the register address and what value to be configured (based on tegra manual register bit fields)

Thanks & Regards,
Sandipan

3

Hi spatra,

Thanks for your information. I checked “JetsonTX2_OEM_Product_DesignGuide” and E17 is marked as reserve.
I want to make it same as below CAN1_STBY in device tree

mttcan@c320000 {
                status = "okay";
                gpio_can_stb = <&tegra_aon_gpio TEGRA_AON_GPIO(AA, 6) GPIO_ACTIVE_HIGH>;
                gpio_can_en = <&tegra_aon_gpio TEGRA_AON_GPIO(AA, 7) GPIO_ACTIVE_HIGH>;
                mram-params = <0 16 16 8 8 8 16 16 16>;
                tx-config = <8 8 0 64>;
                rx-config = <64 64 64>;
        };

so driver can turn on/off appropriately but it look like so complicated. Right?

Thanks and Best Regards,
Vu Nguyen

4

Hi Vu,

In-fact this is the exact way to enable those pins (standby/enable etc.).
By default they are configured as GPIO from the pinmux configuration values.
Hence it is easier to provide the settings from DT to configure as required functionality.

So this has to be followed to keep the functionality static, or if dynamic configuration is preferable then its ok to over write the particular registers from kernel.

Thanks & Regards,
Sandipan