i.MX6DL - GPU Scaling from Userspace

[jameshuang]

I've noticed that the GPU3D clock speed on my imx6 device gets scaled to 1/64 clock speed when it overheats to a particular temperature. It calls gckHARDWARE_SetFscaleValue. 

Is there an easy way from the command line or a C program for me to set the GPU3D clock speed myself? 

James

[igorpadykov]

Hi James

scaling functionality is described in Chapter 24 Dynamic Bus Frequency Driver

attached Linux Manual and one can look at its codes for using in custom application.

Best regards
igor
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[jameshuang]

Thanks Igor,

You pointed me to a chapter on scaling bus frequencies. The GPU is not a bus is it?

The drive code that I think is relevant to me is in Chapter 25 (Thermal Driver).

I had put together this from the code in thermal driver (kernel-module-imx-gpu-viv/gc_hal_kernel_platform_imx6q14.c at master · Freescale/kernel-module-imx-g... ) but I've gotten a little stuck:

IN gckPLATFORM Platform
struct platform_device *pdevice = Platform->device;
gckGALDEVICE galDevice = platform_get_drvdata(pdevice);
if (galDevice) {
  if (galDevice->kernels[gcvCORE_MAJOR]) {
    gckHARDWARE hardware = galDevice->kernels[gcvCORE_MAJOR]->hardware;
    if (hardware) {
      gckHARDWARE_SetFscaleValue(hardware, minFscale);
    }
  }
}

How do I initialize my Platform struct properly? 

What does the "IN" prefix/macro mean? 

[igorpadykov]

Hi James

one can look at description of GPU driver in Chapter 13 and GPU Tools:

IDE - Debug, Compile and Build Tools (15)
IMX6_L4.1.15_2.0.0_GPU_TOOL
https://www.nxp.com/products/processors-and-microcontrollers/applications-processors/i.mx-applicatio...

Also NXP has special service: Professional Services for helping with developing custom drivers.
NXP Professional Services|NXP 

Best regards
igor