| /* |
| * 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 |
| |
| /* Later boards (Kevin rev6+, Gru rev2+) use different regulator ranges. */ |
| int pwm_design_voltage_later[][2] = { |
| [PWM_REGULATOR_GPU] = {7858, 12177}, |
| [PWM_REGULATOR_BIG] = {7987, 13022}, |
| [PWM_REGULATOR_LIT] = {7991, 13037}, |
| [PWM_REGULATOR_CENTERLOG] = {8001, 10497} |
| }; |
| |
| 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) && |
| !(IS_ENABLED(CONFIG_BOARD_GOOGLE_GRU) && board_id() < 2)) { |
| voltage_min = pwm_design_voltage_later[pwm][0]; |
| voltage_max = pwm_design_voltage_later[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); |
| } |