// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
//
// Copyright (c) 2018 Mellanox Technologies. All rights reserved.
// Copyright (c) 2018 Vadim Pasternak <vadimp@mellanox.com>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/module.h>
#include <linux/platform_data/mlxreg.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/thermal.h>
#define MLXREG_FAN_MAX_TACHO 12
#define MLXREG_FAN_MAX_STATE 10
#define MLXREG_FAN_MIN_DUTY 51 /* 20% */
#define MLXREG_FAN_MAX_DUTY 255 /* 100% */
/*
* Minimum and maximum FAN allowed speed in percent: from 20% to 100%. Values
* MLXREG_FAN_MAX_STATE + x, where x is between 2 and 10 are used for
* setting FAN speed dynamic minimum. For example, if value is set to 14 (40%)
* cooling levels vector will be set to 4, 4, 4, 4, 4, 5, 6, 7, 8, 9, 10 to
* introduce PWM speed in percent: 40, 40, 40, 40, 40, 50, 60. 70, 80, 90, 100.
*/
#define MLXREG_FAN_SPEED_MIN (MLXREG_FAN_MAX_STATE + 2)
#define MLXREG_FAN_SPEED_MAX (MLXREG_FAN_MAX_STATE * 2)
#define MLXREG_FAN_SPEED_MIN_LEVEL 2 /* 20 percent */
#define MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF 44
#define MLXREG_FAN_TACHO_DIV_MIN 283
#define MLXREG_FAN_TACHO_DIV_DEF (MLXREG_FAN_TACHO_DIV_MIN * 4)
#define MLXREG_FAN_TACHO_DIV_SCALE_MAX 64
/*
* FAN datasheet defines the formula for RPM calculations as RPM = 15/t-high.
* The logic in a programmable device measures the time t-high by sampling the
* tachometer every t-sample (with the default value 11.32 uS) and increment
* a counter (N) as long as the pulse has not change:
* RPM = 15 / (t-sample * (K + Regval)), where:
* Regval: is the value read from the programmable device register;
* - 0xff - represents tachometer fault;
* - 0xfe - represents tachometer minimum value , which is 4444 RPM;
* - 0x00 - represents tachometer maximum value , which is 300000 RPM;
* K: is 44 and it represents the minimum allowed samples per pulse;
* N: is equal K + Regval;
* In order to calculate RPM from the register value the following formula is
* used: RPM = 15 / ((Regval + K) * 11.32) * 10^(-6)), which in the
* default case is modified to:
* RPM = 15000000 * 100 / ((Regval + 44) * 1132);
* - for Regval 0x00, RPM will be 15000000 * 100 / (44 * 1132) = 30115;
* - for Regval 0xfe, RPM will be 15000000 * 100 / ((254 + 44) * 1132) = 4446;
* In common case the formula is modified to:
* RPM = 15000000 * 100 / ((Regval + samples) * divider).
*/
#define MLXREG_FAN_GET_RPM(rval, d, s) (DIV_ROUND_CLOSEST(15000000 * 100, \
((rval) + (s)) * (d)))
#define MLXREG_FAN_GET_FAULT(val, mask) ((val) == (mask))
#define MLXREG_FAN_PWM_DUTY2STATE(duty) (DIV_ROUND_CLOSEST((duty) * \
MLXREG_FAN_MAX_STATE, \
MLXREG_FAN_MAX_DUTY))
#define MLXREG_FAN_PWM_STATE2DUTY(stat) (DIV_ROUND_CLOSEST((stat) * \
MLXREG_FAN_MAX_DUTY, \
MLXREG_FAN_MAX_STATE))
/*
* struct mlxreg_fan_tacho - tachometer data (internal use):
*
* @connected: indicates if tachometer is connected;
* @reg: register offset;
* @mask: fault mask;
*/
struct mlxreg_fan_tacho {
bool connected;
u32 reg;
u32 mask;
};
/*
* struct mlxreg_fan_pwm - PWM data (internal use):
*
* @connected: indicates if PWM is connected;
* @reg: register offset;
*/
struct mlxreg_fan_pwm {
bool connected;
u32 reg;
};
/*
* struct mlxreg_fan - private data (internal use):
*
* @dev: basic device;
* @regmap: register map of parent device;
* @tacho: tachometer data;
* @pwm: PWM data;
* @samples: minimum allowed samples per pulse;
* @divider: divider value for tachometer RPM calculation;
* @cooling: cooling device levels;
* @cdev: cooling device;
*/
struct mlxreg_fan {
struct device *dev;
void *regmap;
struct mlxreg_core_platform_data *pdata;
struct mlxreg_fan_tacho tacho[MLXREG_FAN_MAX_TACHO];
struct mlxreg_fan_pwm pwm;
int samples;
int divider;
u8 cooling_levels[MLXREG_FAN_MAX_STATE + 1];
struct thermal_cooling_device *cdev;
};
static int
mlxreg_fan_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, long *val)
{
struct mlxreg_fan *fan = dev_get_drvdata(dev);
struct mlxreg_fan_tacho *tacho;
u32 regval;
int err;
switch (type) {
case hwmon_fan:
tacho = &fan->tacho[channel];
switch (attr) {
case hwmon_fan_input:
err = regmap_read(fan->regmap, tacho->reg, ®val);
if (err)
return err;
*val = MLXREG_FAN_GET_RPM(regval, fan->divider,
fan->samples);
break;
case hwmon_fan_fault:
err = regmap_read(fan->regmap, tacho->reg, ®val);
if (err)
return err;
*val = MLXREG_FAN_GET_FAULT(regval, tacho->mask);
break;
default:
return -EOPNOTSUPP;
}
break;
case hwmon_pwm:
switch (attr) {
case hwmon_pwm_input:
err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
if (err)
return err;
*val = regval;
break;
default:
return -EOPNOTSUPP;
}
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int
mlxreg_fan_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
int channel, long val)
{
struct mlxreg_fan *fan = dev_get_drvdata(dev);
switch (type) {
case hwmon_pwm:
switch (attr) {
case hwmon_pwm_input:
if (val < MLXREG_FAN_MIN_DUTY ||
val > MLXREG_FAN_MAX_DUTY)
return -EINVAL;
return regmap_write(fan->regmap, fan->pwm.reg, val);
default:
return -EOPNOTSUPP;
}
break;
default:
return -EOPNOTSUPP;
}
return -EOPNOTSUPP;
}
static umode_t
mlxreg_fan_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr,
int channel)
{
switch (type) {
case hwmon_fan:
if (!(((struct mlxreg_fan *)data)->tacho[channel].connected))
return 0;
switch (attr) {
case hwmon_fan_input:
case hwmon_fan_fault:
return 0444;
default:
break;
}
break;
case hwmon_pwm:
if (!(((struct mlxreg_fan *)data)->pwm.connected))
return 0;
switch (attr) {
case hwmon_pwm_input:
return 0644;
default:
break;
}
break;
default:
break;
}
return 0;
}
static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = {
HWMON_CHANNEL_INFO(fan,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT,
HWMON_F_INPUT | HWMON_F_FAULT),
HWMON_CHANNEL_INFO(pwm,
HWMON_PWM_INPUT),
NULL
};
static const struct hwmon_ops mlxreg_fan_hwmon_hwmon_ops = {
.is_visible = mlxreg_fan_is_visible,
.read = mlxreg_fan_read,
.write = mlxreg_fan_write,
};
static const struct hwmon_chip_info mlxreg_fan_hwmon_chip_info = {
.ops = &mlxreg_fan_hwmon_hwmon_ops,
.info = mlxreg_fan_hwmon_info,
};
static int mlxreg_fan_get_max_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
*state = MLXREG_FAN_MAX_STATE;
return 0;
}
static int mlxreg_fan_get_cur_state(struct thermal_cooling_device *cdev,
unsigned long *state)
{
struct mlxreg_fan *fan = cdev->devdata;
u32 regval;
int err;
err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
if (err) {
dev_err(fan->dev, "Failed to query PWM duty\n");
return err;
}
*state = MLXREG_FAN_PWM_DUTY2STATE(regval);
return 0;
}
static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct mlxreg_fan *fan = cdev->devdata;
unsigned long cur_state;
u32 regval;
int i;
int err;
/*
* Verify if this request is for changing allowed FAN dynamical
* minimum. If it is - update cooling levels accordingly and update
* state, if current state is below the newly requested minimum state.
* For example, if current state is 5, and minimal state is to be
* changed from 4 to 6, fan->cooling_levels[0 to 5] will be changed all
* from 4 to 6. And state 5 (fan->cooling_levels[4]) should be
* overwritten.
*/
if (state >= MLXREG_FAN_SPEED_MIN && state <= MLXREG_FAN_SPEED_MAX) {
state -= MLXREG_FAN_MAX_STATE;
for (i = 0; i < state; i++)
fan->cooling_levels[i] = state;
for (i = state; i <= MLXREG_FAN_MAX_STATE; i++)
fan->cooling_levels[i] = i;
err = regmap_read(fan->regmap, fan->pwm.reg, ®val);
if (err) {
dev_err(fan->dev, "Failed to query PWM duty\n");
return err;
}
cur_state = MLXREG_FAN_PWM_DUTY2STATE(regval);
if (state < cur_state)
return 0;
state = cur_state;
}
if (state > MLXREG_FAN_MAX_STATE)
return -EINVAL;
/* Normalize the state to the valid speed range. */
state = fan->cooling_levels[state];
err = regmap_write(fan->regmap, fan->pwm.reg,
MLXREG_FAN_PWM_STATE2DUTY(state));
if (err) {
dev_err(fan->dev, "Failed to write PWM duty\n");
return err;
}
return 0;
}
static const struct thermal_cooling_device_ops mlxreg_fan_cooling_ops = {
.get_max_state = mlxreg_fan_get_max_state,
.get_cur_state = mlxreg_fan_get_cur_state,
.set_cur_state = mlxreg_fan_set_cur_state,
};
static int mlxreg_fan_connect_verify(struct mlxreg_fan *fan,
struct mlxreg_core_data *data)
{
u32 regval;
int err;
err = regmap_read(fan->regmap, data->capability, ®val);
if (err) {
dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
data->capability);
return err;
}
return !!(regval & data->bit);
}
static int mlxreg_fan_speed_divider_get(struct mlxreg_fan *fan,
struct mlxreg_core_data *data)
{
u32 regval;
int err;
err = regmap_read(fan->regmap, data->capability, ®val);
if (err) {
dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
data->capability);
return err;
}
/*
* Set divider value according to the capability register, in case it
* contains valid value. Otherwise use default value. The purpose of
* this validation is to protect against the old hardware, in which
* this register can return zero.
*/
if (regval > 0 && regval <= MLXREG_FAN_TACHO_DIV_SCALE_MAX)
fan->divider = regval * MLXREG_FAN_TACHO_DIV_MIN;
return 0;
}
static int mlxreg_fan_config(struct mlxreg_fan *fan,
struct mlxreg_core_platform_data *pdata)
{
struct mlxreg_core_data *data = pdata->data;
bool configured = false;
int tacho_num = 0, i;
int err;
fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF;
fan->divider = MLXREG_FAN_TACHO_DIV_DEF;
for (i = 0; i < pdata->counter; i++, data++) {
if (strnstr(data->label, "tacho", sizeof(data->label))) {
if (tacho_num == MLXREG_FAN_MAX_TACHO) {
dev_err(fan->dev, "too many tacho entries: %s\n",
data->label);
return -EINVAL;
}
if (data->capability) {
err = mlxreg_fan_connect_verify(fan, data);
if (err < 0)
return err;
else if (!err) {
tacho_num++;
continue;
}
}
fan->tacho[tacho_num].reg = data->reg;
fan->tacho[tacho_num].mask = data->mask;
fan->tacho[tacho_num++].connected = true;
} else if (strnstr(data->label, "pwm", sizeof(data->label))) {
if (fan->pwm.connected) {
dev_err(fan->dev, "duplicate pwm entry: %s\n",
data->label);
return -EINVAL;
}
fan->pwm.reg = data->reg;
fan->pwm.connected = true;
} else if (strnstr(data->label, "conf", sizeof(data->label))) {
if (configured) {
dev_err(fan->dev, "duplicate conf entry: %s\n",
data->label);
return -EINVAL;
}
/* Validate that conf parameters are not zeros. */
if (!data->mask && !data->bit && !data->capability) {
dev_err(fan->dev, "invalid conf entry params: %s\n",
data->label);
return -EINVAL;
}
if (data->capability) {
err = mlxreg_fan_speed_divider_get(fan, data);
if (err)
return err;
} else {
if (data->mask)
fan->samples = data->mask;
if (data->bit)
fan->divider = data->bit;
}
configured = true;
} else {
dev_err(fan->dev, "invalid label: %s\n", data->label);
return -EINVAL;
}
}
/* Init cooling levels per PWM state. */
for (i = 0; i < MLXREG_FAN_SPEED_MIN_LEVEL; i++)
fan->cooling_levels[i] = MLXREG_FAN_SPEED_MIN_LEVEL;
for (i = MLXREG_FAN_SPEED_MIN_LEVEL; i <= MLXREG_FAN_MAX_STATE; i++)
fan->cooling_levels[i] = i;
return 0;
}
static int mlxreg_fan_probe(struct platform_device *pdev)
{
struct mlxreg_core_platform_data *pdata;
struct device *dev = &pdev->dev;
struct mlxreg_fan *fan;
struct device *hwm;
int err;
pdata = dev_get_platdata(dev);
if (!pdata) {
dev_err(dev, "Failed to get platform data.\n");
return -EINVAL;
}
fan = devm_kzalloc(dev, sizeof(*fan), GFP_KERNEL);
if (!fan)
return -ENOMEM;
fan->dev = dev;
fan->regmap = pdata->regmap;
err = mlxreg_fan_config(fan, pdata);
if (err)
return err;
hwm = devm_hwmon_device_register_with_info(dev, "mlxreg_fan",
fan,
&mlxreg_fan_hwmon_chip_info,
NULL);
if (IS_ERR(hwm)) {
dev_err(dev, "Failed to register hwmon device\n");
return PTR_ERR(hwm);
}
if (IS_REACHABLE(CONFIG_THERMAL)) {
fan->cdev = devm_thermal_of_cooling_device_register(dev,
NULL, "mlxreg_fan", fan, &mlxreg_fan_cooling_ops);
if (IS_ERR(fan->cdev)) {
dev_err(dev, "Failed to register cooling device\n");
return PTR_ERR(fan->cdev);
}
}
return 0;
}
static struct platform_driver mlxreg_fan_driver = {
.driver = {
.name = "mlxreg-fan",
},
.probe = mlxreg_fan_probe,
};
module_platform_driver(mlxreg_fan_driver);
MODULE_AUTHOR("Vadim Pasternak <vadimp@mellanox.com>");
MODULE_DESCRIPTION("Mellanox FAN driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:mlxreg-fan");
