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/*
* This file is part of the coreboot project.
*
* Copyright 2016 Rockchip Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <arch/io.h>
#include <assert.h>
#include <boardid.h>
#include <console/console.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 8000
#define PWM_DESIGN_VOLTAGE_MAX 15000
/* The min & max design voltages are different after kevin-r6 */
int kevin_voltage_min_max_r6[][2] = {
[PWM_REGULATOR_GPU] = {7910, 12139},
[PWM_REGULATOR_BIG] = {7986, 13057},
[PWM_REGULATOR_LIT] = {7997, 13002},
[PWM_REGULATOR_CENTERLOG] = {7996, 10507}
};
void pwm_regulator_configure(enum pwm_regulator pwm, int millivolt)
{
int duty_ns, voltage_max, voltage_min;
int voltage = millivolt * 10; /* for higer calculation accuracy */
switch (pwm) {
case PWM_REGULATOR_GPU:
write32(&rk3399_grf->iomux_pwm_0, IOMUX_PWM_0);
break;
case PWM_REGULATOR_BIG:
write32(&rk3399_grf->iomux_pwm_1, IOMUX_PWM_1);
break;
case PWM_REGULATOR_LIT:
write32(&rk3399_pmugrf->iomux_pwm_2, IOMUX_PWM_2);
break;
case PWM_REGULATOR_CENTERLOG:
write32(&rk3399_pmugrf->iomux_pwm_3a, IOMUX_PWM_3_A);
break;
}
voltage_min = PWM_DESIGN_VOLTAGE_MIN;
voltage_max = PWM_DESIGN_VOLTAGE_MAX;
if (IS_ENABLED(CONFIG_BOARD_GOOGLE_KEVIN) && board_id() >= 6) {
voltage_min = kevin_voltage_min_max_r6[pwm][0];
voltage_max = kevin_voltage_min_max_r6[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, PWM_PERIOD, duty_ns);
}
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