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/* Copyright 2013 The ChromiumOS Authors
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
/* Fan control module for Chrome EC */
#ifndef __CROS_EC_FAN_H
#define __CROS_EC_FAN_H
#include "config.h"
#include <stdbool.h>
#include <stdint.h>
#ifdef CONFIG_ZEPHYR
#ifdef CONFIG_PLATFORM_EC_FAN
#include <zephyr/devicetree.h>
#define NODE_ID_AND_COMMA(node_id) node_id,
enum fan_channel {
#if DT_NODE_EXISTS(DT_INST(0, cros_ec_fans))
DT_FOREACH_CHILD(DT_INST(0, cros_ec_fans), NODE_ID_AND_COMMA)
#endif /* cros_ec_fans */
FAN_CH_COUNT
};
BUILD_ASSERT(FAN_CH_COUNT == CONFIG_PLATFORM_EC_NUM_FANS);
#endif /* CONFIG_PLATFORM_EC_FAN */
#endif /* CONFIG_ZEPHYR */
/**
* STOPPED means not spinning.
*
* When setting fan rpm, some implementations in chip layer (npcx and it83xx)
* is to adjust fan pwm duty steps by steps. In this period, fan_status will
* be marked as CHANGING. After change is done, fan_status will become LOCKED.
*
* In the period of changing pwm duty, if it's trying to increase/decrease duty
* even when duty is already in upper/lower bound. Then this action won't work,
* and fan_status will be marked as FRUSTRATED.
*
* For other implementations in chip layer (mchp), there is no
* changing period. So they don't have CHANGING status.
* Just return status as LOCKED in normal spinning case, return STOPPED when
* not spinning, return FRUSTRATED when the related flags (which is read from
* chip's register) is set.
*/
enum fan_status {
FAN_STATUS_STOPPED = 0,
FAN_STATUS_CHANGING = 1,
FAN_STATUS_LOCKED = 2,
FAN_STATUS_FRUSTRATED = 3
};
/* Fan mode */
enum fan_mode {
/* FAN rpm mode */
FAN_RPM = 0,
/* FAN duty mode */
FAN_DUTY,
};
struct fan_conf {
unsigned int flags;
/* Hardware channel number (the meaning is chip-specific) */
int ch;
/* Active-high power_good input GPIO, or -1 if none */
int pgood_gpio;
/* Active-high power_enable output GPIO, or -1 if none */
int enable_gpio;
};
struct fan_rpm {
/* rpm_min is to keep turning. rpm_start is to begin turning */
int rpm_min;
int rpm_start;
int rpm_max;
uint8_t rpm_deviation;
};
/* Characteristic of each physical fan */
struct fan_t {
const struct fan_conf *conf;
const struct fan_rpm *rpm;
};
/* Fan status data structure */
struct fan_data {
/* Fan mode */
enum fan_mode current_fan_mode;
/* Actual rpm */
int rpm_actual;
/* Previous rpm */
int rpm_pre;
/* Target rpm */
int rpm_target;
/* Fan config flags */
unsigned int flags;
/* Automatic fan status */
enum fan_status auto_status;
/* Current PWM duty cycle percentage */
int pwm_percent;
/* Whether the PWM channel is enabled */
bool pwm_enabled;
};
/* Values for .flags field */
/* Enable automatic RPM control using tach input */
#define FAN_USE_RPM_MODE BIT(0)
/* Require a higher duty cycle to start up than to keep running */
#define FAN_USE_FAST_START BIT(1)
/* The list of fans is instantiated in board.c. */
#ifdef CONFIG_FAN_DYNAMIC
extern struct fan_t fans[];
#else
extern const struct fan_t fans[];
#endif
/* For convenience */
#define FAN_CH(fan) fans[fan].conf->ch
/* Calculate temp_ratio as a macro. common/thermal.c defines the same
* function, but it cannot be used at file scope.
*/
#define THERMAL_FAN_PERCENT(low, high, cur) \
(((low) < (cur) && (cur) < (high)) ? \
(100 * ((cur) - (low)) / ((high) - (low))) : \
((cur) <= (low) ? 0 : 100))
/* Convert a temperature in centigrade to a temp_ratio, assuming constants
* temp_fan_off, temp_fan_max, already in Kelvin. Helpful for fan tables.
*/
#define TEMP_TO_RATIO(temp_c) \
(THERMAL_FAN_PERCENT((temp_fan_off), (temp_fan_max), (C_TO_K(temp_c))))
/**
* Set the amount of active cooling needed. The thermal control task will call
* this frequently, and the fan control logic will attempt to provide it.
*
* @param fan Fan number (index into fans[])
* @param pct Percentage of cooling effort needed (0 - 100)
*/
void fan_set_percent_needed(int fan, int pct);
/**
* Convert temp_ratio (temperature as a percentage of the ec_thermal_config
* .temp_fan_off to .temp_fan_max range, also cooling effort needed) into a
* target fan RPM.
* The default implementation should be sufficient for most needs, but
* individual boards may provide a custom version if needed (see config.h).
*
* @param fan Fan number (index into fans[])
* @param temp_ratio Temperature as fraction of temp_fan_off to
* temp_fan_max range, expressed as a percent ([0,100]).
* Return Target RPM for fan
*/
int fan_percent_to_rpm(int fan, int temp_ratio);
/* Data structure to hold a tuple of parameters for one sensor and one fan. */
struct fan_step_1_1 {
/* lowest temp_ratio (exclusive) to apply this rpm when decreasing.
* Use this rpm until temp_ratio falls to or below this threshold.
*/
int decreasing_temp_ratio_threshold;
/* lowest temp_ratio (inclusive) to apply this rpm when increasing.
* Use this rpm when temp_ratio exceeds this threshold.
*/
int increasing_temp_ratio_threshold;
int rpm;
};
/**
* Convert temp_ratio (temperature as a percentage of the ec_thermal_config
* .temp_fan_off to .temp_fan_max range) into a target fan RPM.
*
* This function adapts the most popular custom version of fan_percent_to_rpm,
* which provides hysteresis to reduce temperature/fan speed oscillations.
*
* To refactor to this, convert the fan_step-based fan_table to fan_step_1_1 by
* removing the first (.rpm = 0) element and using
* decreasing/increasing_temp_ratio_threshold for off/on respectively.
* See example in ../test/fan.c.
*
* @param fan_table Pointer to ordered array of fan_step_1_1 structs.
* There is no need to have any element with .rpm = 0.
* Function assumes 0 when temp_ratio is below the
* thresholds in the index-0 element.
* @param num_fan_levels Size of fan_table
* @param fan_index Fan number (index into fans[])
* @param temp_ratio Temperature as fraction of temp_fan_off to
* temp_fan_max range, expressed as a percent ([0,100]).
* @param on_change Pointer to function to be run when the target fan
* rpm changes, such as ezkinil board_print_temps().
* Return Target RPM for fan
*/
int temp_ratio_to_rpm_hysteresis(const struct fan_step_1_1 *fan_table,
int num_fan_levels, int fan_index,
int temp_ratio, void (*on_change)(void));
/**
* These functions require chip-specific implementations.
*/
/* Enable/Disable the fan controller */
void fan_set_enabled(int ch, int enabled);
int fan_get_enabled(int ch);
/* Fixed pwm duty cycle (0-100%) */
void fan_set_duty(int ch, int percent);
int fan_get_duty(int ch);
/* Enable/Disable automatic RPM control using tach feedback */
void fan_set_rpm_mode(int ch, int rpm_mode);
int fan_get_rpm_mode(int ch);
/* Set the target for the automatic RPM control */
void fan_set_rpm_target(int ch, int rpm);
int fan_get_rpm_actual(int ch);
int fan_get_rpm_target(int ch);
/* Is the fan stalled when it shouldn't be? */
int fan_is_stalled(int ch);
enum fan_status fan_get_status(int ch);
/* Initialize the HW according to the desired flags */
void fan_channel_setup(int ch, unsigned int flags);
int fan_get_count(void);
void fan_set_count(int count);
int is_thermal_control_enabled(int idx);
#ifdef CONFIG_ZEPHYR
extern struct fan_data fan_data[];
/**
* This function sets PWM duty based on target RPM.
*
* The target and current RPM values in fan_data entry that
* corresponds to selected fan has to be updated before this
* function is called.
*
* @param ch Fan number (index into fan_data[] and fans[])
* Return Fan status (see fan_status enum definition)
*/
enum fan_status board_override_fan_control_duty(int ch);
#endif
#endif /* __CROS_EC_FAN_H */
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