Hi All, Good day! I’ve been doing some PTN3460 programming under Linux using C/C++ and I have some questions regarding on setting the brightness level to my display device. The display device with PTN3460 is connected in DP (display port) to my computer. Only needs a DisplayPort native AUX command to access DPCD address from PTN3460. I’m currently looking into the DRM (Direct Rendering Manager) a subsystem of the Linux kernel. It has a methods drm_dp_dpcd_readb, drm_dp_dpcd_read and drm_dp_dpcd_write.
Do you have any suggestions or advice how to use the kernel driver in DRM in regards to how to implement the method drm_dp_dpcd_readb for example? I couldn't not find any test tool examples that implement it. Biggest concern is I don't have sufficient knowledge where to start what to code using the DRM module.
Namedrm_dp_dpcd_readb — read a single byte from the DPCDSynopsisssize_t drm_dp_dpcd_readb ( struct drm_dp_aux * aux, unsigned int offset, u8 * valuep); Argumentsaux - DisplayPort AUX channeloffset - address of the register to readvaluep - location where the value of the register will be storedDescriptionReturns the number of bytes transferred (1) on success, or a negative error code on failure. Regards,John