pwm_regulator.c

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#include <device/mmio.h>
#include <assert.h>
#include <boardid.h>
#include <console/console.h>
#include <gpio.h>
#include <soc/grf.h>
#include <soc/pwm.h>
 
#include "pwm_regulator.h"
 
/*
 * Apparently a period of 3333 is determined by EEs to be ideal for our
 * board design / resistors / capacitors / regulators but due to
 * clock dividers we actually get 3337.
 */
#define PWM_PERIOD                      3337
#define PWM_DESIGN_VOLTAGE_MIN_OUTDATED 8000
#define PWM_DESIGN_VOLTAGE_MAX_OUTDATED 15000
 
/* Applies for Kevin rev6+ */
int kevin6_pwm_design_voltage[][2] = {
        [PWM_REGULATOR_GPU] = {7858, 12177},
        [PWM_REGULATOR_BIG] = {7987, 13022},
        [PWM_REGULATOR_LIT] = {7991, 13037},
        [PWM_REGULATOR_CENTERLOG] = {8001, 10497}
};
 
/* Applies for Gru rev2+, Bob, and Nefario. */
int pwm_design_voltage[][2] = {
        [PWM_REGULATOR_GPU] = {7864, 12177},
        [PWM_REGULATOR_BIG] = {8001, 13022},
        [PWM_REGULATOR_LIT] = {7977, 13078},
        [PWM_REGULATOR_CENTERLOG] = {7994, 10499}
};
 
/* Applies for Scarlet-based boards. */
int scarlet_pwm_design_voltage[][2] = {
        [PWM_REGULATOR_GPU] = {7996, 10990},
        [PWM_REGULATOR_BIG] = {8000, 12992},
        [PWM_REGULATOR_LIT] = {8021, 11996},
};
 
int pwm_enum_to_pwm_number[] = {
        [PWM_REGULATOR_GPU] = 0,
        [PWM_REGULATOR_LIT] = 2,
#if CONFIG(GRU_HAS_CENTERLOG_PWM)
        [PWM_REGULATOR_CENTERLOG] = 3,
#else
        [PWM_REGULATOR_CENTERLOG] = -1,
#endif
#if CONFIG(GRU_BASEBOARD_SCARLET)
        [PWM_REGULATOR_BIG] = 3,
#else
        [PWM_REGULATOR_BIG] = 1,
#endif
};
 
void pwm_regulator_configure(enum pwm_regulator pwm, int millivolt)
{
        int duty_ns, voltage_max, voltage_min;
        int voltage = millivolt * 10; /* for higher calculation accuracy */
        int pwm_number = pwm_enum_to_pwm_number[pwm];
 
        voltage_min = pwm_design_voltage[pwm][0];
        voltage_max = pwm_design_voltage[pwm][1];
        if ((CONFIG(BOARD_GOOGLE_KEVIN) && board_id() < 6) ||
            (CONFIG(BOARD_GOOGLE_GRU) && board_id() < 2)) {
                voltage_min = PWM_DESIGN_VOLTAGE_MIN_OUTDATED;
                voltage_max = PWM_DESIGN_VOLTAGE_MAX_OUTDATED;
        } else if (CONFIG(BOARD_GOOGLE_KEVIN) && board_id() >= 6) {
                voltage_min = kevin6_pwm_design_voltage[pwm][0];
                voltage_max = kevin6_pwm_design_voltage[pwm][1];
        } else if (CONFIG(GRU_BASEBOARD_SCARLET)) {
                voltage_min = scarlet_pwm_design_voltage[pwm][0];
                voltage_max = scarlet_pwm_design_voltage[pwm][1];
        }
 
        assert(voltage <= voltage_max && voltage >= voltage_min);
 
        /*
         * Intentionally round down (higher volt) to be safe.
         * eg, for the default min & max design voltage:
         *    period = 3337, volt = 1.1: 1906
         *    period = 3337, volt = 1.0: 2383
         *    period = 3337, volt = 0.9: 2860
         */
        duty_ns = PWM_PERIOD * (voltage_max - voltage)
                             / (voltage_max - voltage_min);
 
        pwm_init(pwm_number, PWM_PERIOD, duty_ns);
 
        switch (pwm_number) {
        case 0:
                gpio_input(GPIO(4, C, 2));      /* PWM0 remove pull-down */
                write32(&rk3399_grf->iomux_pwm_0, IOMUX_PWM_0);
                break;
        case 1:
                gpio_input(GPIO(4, C, 6));      /* PWM1 remove pull-down */
                write32(&rk3399_grf->iomux_pwm_1, IOMUX_PWM_1);
                break;
        case 2:
                gpio_input(GPIO(1, C, 3));      /* PWM2 remove pull-down */
                write32(&rk3399_pmugrf->iomux_pwm_2, IOMUX_PWM_2);
                break;
        case 3:
                gpio_input(GPIO(0, A, 6));      /* PWM3 remove pull-down */
                write32(&rk3399_pmugrf->iomux_pwm_3a, IOMUX_PWM_3_A);
                break;
        default:
                die("incorrect board configuration");
        }
}