Linux Device Drivers Development

Setting the controller's parameters

The fp_ops->fb_set_par hook is another hardware-specific hook, responsible for sending parameters to the hardware. It programs the hardware based on user settings (info->var):

static int myfb_set_par(struct fb_info *info) 
{ 
   struct fb_var_screeninfo *var = &info->var; 
 
   /* Make some compute or other sanity check */ 
   [...] 
 
    /* 
     * This function writes value to the hardware, 
     * in the appropriate registers 
     */ 
   set_controller_vars(var, info); 
 
   return 0; 
}