src/mainboard/google/gru/boardid.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <boardid.h>
   4 #include <console/console.h>
   5 #include <gpio.h>
   6 #include <soc/saradc.h>
   7
   8 static const int id_readings[] = {
   9 /*      ID : Volts : ADC value :    Bucket      */
  10 /*      ==   =====   =========    ==========    */
  11 #if CONFIG(BOARD_GOOGLE_KEVIN)
  12 /*       0 : 0.109V:        62 :    0 -   91    */      91,
  13 #else
  14 /*       0 : 0.074V:        42 :    0 -   81    */      81,
  15 #endif
  16 /*       1 : 0.211V:       120 :   82 -  150    */      150,
  17 /*       2 : 0.319V:       181 :  151 -  211    */      211,
  18 /*       3 : 0.427V:       242 :  212 -  274    */      274,
  19 /*       4 : 0.542V:       307 :  275 -  342    */      342,
  20 /*       5 : 0.666V:       378 :  343 -  411    */      411,
  21 /*       6 : 0.781V:       444 :  412 -  477    */      477,
  22 /*       7 : 0.900V:       511 :  478 -  545    */      545,
  23 /*       8 : 1.023V:       581 :  546 -  613    */      613,
  24 /*       9 : 1.137V:       646 :  614 -  675    */      675,
  25 /*      10 : 1.240V:       704 :  676 -  733    */      733,
  26 /*      11 : 1.343V:       763 :  734 -  795    */      795,
  27 /*      12 : 1.457V:       828 :  796 -  861    */      861,
  28 /*      13 : 1.576V:       895 :  862 -  925    */      925,
  29 /*      14 : 1.684V:       956 :  926 -  989    */      989,
  30 /*      15 : 1.800V:      1023 :  990 - 1023    */      1023
  31 };
  32 _Static_assert(ARRAY_SIZE(id_readings) == 16, "Yo' messed up da table, bruh!");
  33 static int cached_board_id = -1;
  34 static int cached_ram_id = -1;
  35
  36 static uint32_t get_index(uint32_t channel, int *cached_id)
  37 {
  38         int i;
  39         int adc_reading;
  40
  41         if (*cached_id != -1)
  42                 return *cached_id;
  43
  44         adc_reading = get_saradc_value(channel);
  45         for (i = 0; i < ARRAY_SIZE(id_readings); i++) {
  46                 if (adc_reading <= id_readings[i]) {
  47                         printk(BIOS_DEBUG, "ADC reading %d, ID %d\n",
  48                                adc_reading, i);
  49                         *cached_id = i;
  50                         return i;
  51                 }
  52         }
  53
  54         die("Read impossible value (> 1023) from 10-bit ADC!");
  55 }
  56
  57 uint32_t board_id(void)
  58 {
  59         return get_index(1, &cached_board_id);
  60 }
  61
  62 uint32_t ram_code(void)
  63 {
  64         return get_index(0, &cached_ram_id);
  65 }
  66
  67 uint32_t sku_id(void)
  68 {
  69         if (!CONFIG(GRU_BASEBOARD_SCARLET))
  70                 return UNDEFINED_STRAPPING_ID;
  71
  72         static uint32_t sku_id = UNDEFINED_STRAPPING_ID;
  73         if (sku_id != UNDEFINED_STRAPPING_ID)
  74                 return sku_id;
  75
  76         gpio_t pins[3] = {[2] = GPIO(3, D, 6), [1] = GPIO(3, D, 5),
  77                           [0] = GPIO(3, D, 4)}; /* GPIO3_D4 is LSB */
  78
  79         sku_id = gpio_pullup_base2_value(pins, ARRAY_SIZE(pins));
  80         return sku_id;
  81 }