src/mainboard/google/gru/pwm_regulator.c

   1 /*
   2  * This file is part of the coreboot project.
   3  *
   4  * Copyright 2016 Rockchip Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; version 2 of the License.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <device/mmio.h>
  17 #include <assert.h>
  18 #include <boardid.h>
  19 #include <console/console.h>
  20 #include <gpio.h>
  21 #include <soc/grf.h>
  22 #include <soc/pwm.h>
  23
  24 #include "pwm_regulator.h"
  25
  26 /*
  27  * Apparently a period of 3333 is determined by EEs to be ideal for our
  28  * board design / resistors / capacitors / regulators but due to
  29  * clock dividers we actually get 3337.
  30  */
  31 #define PWM_PERIOD                      3337
  32 #define PWM_DESIGN_VOLTAGE_MIN_OUTDATED 8000
  33 #define PWM_DESIGN_VOLTAGE_MAX_OUTDATED 15000
  34
  35 /* Applies for Kevin rev6+ */
  36 int kevin6_pwm_design_voltage[][2] = {
  37         [PWM_REGULATOR_GPU] = {7858, 12177},
  38         [PWM_REGULATOR_BIG] = {7987, 13022},
  39         [PWM_REGULATOR_LIT] = {7991, 13037},
  40         [PWM_REGULATOR_CENTERLOG] = {8001, 10497}
  41 };
  42
  43 /* Applies for Gru rev2+, Bob, and Nefario. */
  44 int pwm_design_voltage[][2] = {
  45         [PWM_REGULATOR_GPU] = {7864, 12177},
  46         [PWM_REGULATOR_BIG] = {8001, 13022},
  47         [PWM_REGULATOR_LIT] = {7977, 13078},
  48         [PWM_REGULATOR_CENTERLOG] = {7994, 10499}
  49 };
  50
  51 /* Applies for Scarlet-based boards. */
  52 int scarlet_pwm_design_voltage[][2] = {
  53         [PWM_REGULATOR_GPU] = {7996, 10990},
  54         [PWM_REGULATOR_BIG] = {8000, 12992},
  55         [PWM_REGULATOR_LIT] = {8021, 11996},
  56 };
  57
  58 int pwm_enum_to_pwm_number[] = {
  59         [PWM_REGULATOR_GPU] = 0,
  60         [PWM_REGULATOR_LIT] = 2,
  61 #if CONFIG(GRU_HAS_CENTERLOG_PWM)
  62         [PWM_REGULATOR_CENTERLOG] = 3,
  63 #else
  64         [PWM_REGULATOR_CENTERLOG] = -1,
  65 #endif
  66 #if CONFIG(GRU_BASEBOARD_SCARLET)
  67         [PWM_REGULATOR_BIG] = 3,
  68 #else
  69         [PWM_REGULATOR_BIG] = 1,
  70 #endif
  71 };
  72
  73 void pwm_regulator_configure(enum pwm_regulator pwm, int millivolt)
  74 {
  75         int duty_ns, voltage_max, voltage_min;
  76         int voltage = millivolt * 10; /* for higer calculation accuracy */
  77         int pwm_number = pwm_enum_to_pwm_number[pwm];
  78
  79         voltage_min = pwm_design_voltage[pwm][0];
  80         voltage_max = pwm_design_voltage[pwm][1];
  81         if ((CONFIG(BOARD_GOOGLE_KEVIN) && board_id() < 6) ||
  82             (CONFIG(BOARD_GOOGLE_GRU) && board_id() < 2)) {
  83                 voltage_min = PWM_DESIGN_VOLTAGE_MIN_OUTDATED;
  84                 voltage_max = PWM_DESIGN_VOLTAGE_MAX_OUTDATED;
  85         } else if (CONFIG(BOARD_GOOGLE_KEVIN) && board_id() >= 6) {
  86                 voltage_min = kevin6_pwm_design_voltage[pwm][0];
  87                 voltage_max = kevin6_pwm_design_voltage[pwm][1];
  88         } else if (CONFIG(GRU_BASEBOARD_SCARLET)) {
  89                 voltage_min = scarlet_pwm_design_voltage[pwm][0];
  90                 voltage_max = scarlet_pwm_design_voltage[pwm][1];
  91         }
  92
  93         assert(voltage <= voltage_max && voltage >= voltage_min);
  94
  95         /*
  96          * Intentionally round down (higher volt) to be safe.
  97          * eg, for the default min & max design voltage:
  98          *    period = 3337, volt = 1.1: 1906
  99          *    period = 3337, volt = 1.0: 2383
 100          *    period = 3337, volt = 0.9: 2860
 101          */
 102         duty_ns = PWM_PERIOD * (voltage_max - voltage)
 103                              / (voltage_max - voltage_min);
 104
 105         pwm_init(pwm_number, PWM_PERIOD, duty_ns);
 106
 107         switch (pwm_number) {
 108         case 0:
 109                 gpio_input(GPIO(4, C, 2));      /* PWM0 remove pull-down */
 110                 write32(&rk3399_grf->iomux_pwm_0, IOMUX_PWM_0);
 111                 break;
 112         case 1:
 113                 gpio_input(GPIO(4, C, 6));      /* PWM1 remove pull-down */
 114                 write32(&rk3399_grf->iomux_pwm_1, IOMUX_PWM_1);
 115                 break;
 116         case 2:
 117                 gpio_input(GPIO(1, C, 3));      /* PWM2 remove pull-down */
 118                 write32(&rk3399_pmugrf->iomux_pwm_2, IOMUX_PWM_2);
 119                 break;
 120         case 3:
 121                 gpio_input(GPIO(0, A, 6));      /* PWM3 remove pull-down */
 122                 write32(&rk3399_pmugrf->iomux_pwm_3a, IOMUX_PWM_3_A);
 123                 break;
 124         default:
 125                 die("incorrect board configuration");
 126         }
 127 }