src/mainboard/lenovo/x200/blc.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <stdint.h>
   4 #include <commonlib/helpers.h>
   5 #include <console/console.h>
   6 #include <northbridge/intel/gm45/gm45.h>
   7 #include <drivers/intel/gma/opregion.h>
   8
   9 static const struct blc_pwm_t blc_entries[] = {
  10         /* corrected to 320MHz CDClk, vendor set 753; works fine at both: */
  11         {"LTD121EQ3B", 447},
  12         {"LTD121EWVB", 165},
  13         {"LTD133EQ1B", 264},  /* Found on an X301 */
  14         {"B121EW03 V6 ", 165},
  15         /* datasheets: between 100 and 20k, typical 200 */
  16         /* TESTED: works best at 400 */
  17         {"B121EW09 V3 ", 400},
  18         {"HV121WX4-120", 110}, /* Aftermarket AFFS lcd, works well at low pwm */
  19         {"LTN121AT03001", 110},
  20         {"LTN121AP03001", 750},
  21         /* TODO: untested panels found on thinkwiki */
  22         /* Generally CCFL runs best at lower PWM */
  23         /* {"B121EW09 V2 ", 450}, */
  24         /* {"N121IB-L05", 450}, */
  25         {"LP121WX3-TLC1", 400}, /* TESTED to work best at this value */
  26         /* {"LP121WX3-TLA1" 450}, */
  27         /* {"B121EW03 V3 " 110}, */
  28         /* {"LTN121AP02001" 110}, */
  29 };
  30
  31 int get_blc_values(const struct blc_pwm_t **entries)
  32 {
  33         *entries = blc_entries;
  34         return ARRAY_SIZE(blc_entries);
  35 }
  36
  37 const char *mainboard_vbt_filename(void)
  38 {
  39         u16 pwm_freq;
  40
  41         pwm_freq = get_blc_pwm_freq_value(NULL);
  42
  43         if (pwm_freq == 0) {
  44                 printk(BIOS_DEBUG,
  45                        "GMA: Display backlight type not found, assuming LED\n");
  46                 return "data_led.vbt";
  47         } else if (pwm_freq > 200) {
  48                 printk(BIOS_DEBUG, "GMA: Using LED backlight VBT\n");
  49                 return "data_led.vbt";
  50         } else {
  51                 printk(BIOS_DEBUG, "GMA: Using CCFL backlight VBT\n");
  52                 return "data_ccfl.vbt";
  53         }
  54 }