Where are R and L?

#define CAM0_RST_L TEGRA_MAIN_GPIO(R, 5) R? L?


I am studying DTB.

I don’t know where R, L is defined.

The TEGRA_MAIN_GPIO() and TEGRA_AON_GPIO() are defined in below file.


The TEGRA_MAIN_GPIO(port, offset) are how NVIDIA uniquely identifies individual GPIOs. These each map to a particular pin on the SoC and corresponding GPIO #s in the kernel.

So TEGRA_MAIN_GPIO(R, 1) maps to GPIO R.01 which corresponds to GPIO #457 in the kernel.
TEGRA_MAIN_GPIO(R, 5) maps to GPIO R.05 which corresponds to GPIO #461 in the kernel.

There is an “L” port also, but I’m not sure if that is what you are asking about. Are you thinking that “L” stands for Left and “R” stands for Right?

TEGRA_AON_GPIO(AA, 2) maps to GPIO AA.02 which corresponds to GPIO #298.

The “MAIN” vs. “AON” GPIOs are from different power domains and address spaces so they are set apart from each other. AON stands for Always ON.