imx: mach: imx8: fdt: set correct frequencies for the industrial SoC
Set correct CPU and GPU frequencies for the industrial i.MX8 SoC
variant.
Ensure that the CPU and GPU frequencies are properly configured for the
industrial variant of the SoC. According to the "i.MX 8QuadMax
Industrial Applications Processors" datasheet, the frequency limits for
this variant are as follows:
- Cortex-A72: 1.296 GHz
- Cortex-A53: 1.104 GHz
- GPU core: 625 MHz
- GPU shader: 625 MHz
The CPU clock is enforced by the System Controller Firmware (SCFW), but
the cpufreq driver is unaware of this enforcement. By removing
unsupported frequencies from the operating points, we ensure that the
cpufreq driver aligns correctly with the SCFW's settings.
The GPU frequency, on the other hand, is not enforced by the SCFW. As a
result, the GPU could potentially be overclocked. To prevent this, we
set the correct clock frequency and update the operating points
accordingly, ensuring compliance with the datasheet specifications.
Signed-off-by: Stefan Eichenberger <[email protected]>