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- // SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
- //
- // Copyright (c) 2018 Mellanox Technologies. All rights reserved.
- // Copyright (c) 2018 Vadim Pasternak <[email protected]>
- #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 14
- #define MLXREG_FAN_MAX_PWM 4
- #define MLXREG_FAN_PWM_NOT_CONNECTED 0xff
- #define MLXREG_FAN_MAX_STATE 10
- #define MLXREG_FAN_MIN_DUTY 51 /* 20% */
- #define MLXREG_FAN_MAX_DUTY 255 /* 100% */
- #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;
- /*
- * struct mlxreg_fan_tacho - tachometer data (internal use):
- *
- * @connected: indicates if tachometer is connected;
- * @reg: register offset;
- * @mask: fault mask;
- * @prsnt: present register offset;
- */
- struct mlxreg_fan_tacho {
- bool connected;
- u32 reg;
- u32 mask;
- u32 prsnt;
- };
- /*
- * struct mlxreg_fan_pwm - PWM data (internal use):
- *
- * @fan: private data;
- * @connected: indicates if PWM is connected;
- * @reg: register offset;
- * @cooling: cooling device levels;
- * @last_hwmon_state: last cooling state set by hwmon subsystem;
- * @last_thermal_state: last cooling state set by thermal subsystem;
- * @cdev: cooling device;
- */
- struct mlxreg_fan_pwm {
- struct mlxreg_fan *fan;
- bool connected;
- u32 reg;
- unsigned long last_hwmon_state;
- unsigned long last_thermal_state;
- struct thermal_cooling_device *cdev;
- };
- /*
- * struct mlxreg_fan - private data (internal use):
- *
- * @dev: basic device;
- * @regmap: register map of parent device;
- * @tacho: tachometer data;
- * @pwm: PWM data;
- * @tachos_per_drwr - number of tachometers per drawer;
- * @samples: minimum allowed samples per pulse;
- * @divider: divider value for tachometer RPM calculation;
- */
- 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[MLXREG_FAN_MAX_PWM];
- int tachos_per_drwr;
- int samples;
- int divider;
- };
- static int mlxreg_fan_set_cur_state(struct thermal_cooling_device *cdev,
- unsigned long state);
- 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;
- struct mlxreg_fan_pwm *pwm;
- u32 regval;
- int err;
- switch (type) {
- case hwmon_fan:
- tacho = &fan->tacho[channel];
- switch (attr) {
- case hwmon_fan_input:
- /*
- * Check FAN presence: FAN related bit in presence register is one,
- * if FAN is physically connected, zero - otherwise.
- */
- if (tacho->prsnt && fan->tachos_per_drwr) {
- err = regmap_read(fan->regmap, tacho->prsnt, ®val);
- if (err)
- return err;
- /*
- * Map channel to presence bit - drawer can be equipped with
- * one or few FANs, while presence is indicated per drawer.
- */
- if (BIT(channel / fan->tachos_per_drwr) & regval) {
- /* FAN is not connected - return zero for FAN speed. */
- *val = 0;
- return 0;
- }
- }
- err = regmap_read(fan->regmap, tacho->reg, ®val);
- if (err)
- return err;
- if (MLXREG_FAN_GET_FAULT(regval, tacho->mask)) {
- /* FAN is broken - return zero for FAN speed. */
- *val = 0;
- return 0;
- }
- *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:
- pwm = &fan->pwm[channel];
- switch (attr) {
- case hwmon_pwm_input:
- err = regmap_read(fan->regmap, 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);
- struct mlxreg_fan_pwm *pwm;
- switch (type) {
- case hwmon_pwm:
- switch (attr) {
- case hwmon_pwm_input:
- if (val < MLXREG_FAN_MIN_DUTY ||
- val > MLXREG_FAN_MAX_DUTY)
- return -EINVAL;
- pwm = &fan->pwm[channel];
- /* If thermal is configured - handle PWM limit setting. */
- if (IS_REACHABLE(CONFIG_THERMAL)) {
- pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(val);
- /*
- * Update PWM only in case requested state is not less than the
- * last thermal state.
- */
- if (pwm->last_hwmon_state >= pwm->last_thermal_state)
- return mlxreg_fan_set_cur_state(pwm->cdev,
- pwm->last_hwmon_state);
- return 0;
- }
- return regmap_write(fan->regmap, 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[channel].connected))
- return 0;
- switch (attr) {
- case hwmon_pwm_input:
- return 0644;
- default:
- break;
- }
- break;
- default:
- break;
- }
- return 0;
- }
- static char *mlxreg_fan_name[] = {
- "mlxreg_fan",
- "mlxreg_fan1",
- "mlxreg_fan2",
- "mlxreg_fan3",
- };
- 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_F_INPUT | HWMON_F_FAULT,
- HWMON_F_INPUT | HWMON_F_FAULT),
- HWMON_CHANNEL_INFO(pwm,
- HWMON_PWM_INPUT,
- HWMON_PWM_INPUT,
- HWMON_PWM_INPUT,
- 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_pwm *pwm = cdev->devdata;
- struct mlxreg_fan *fan = pwm->fan;
- u32 regval;
- int err;
- err = regmap_read(fan->regmap, 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_pwm *pwm = cdev->devdata;
- struct mlxreg_fan *fan = pwm->fan;
- int err;
- if (state > MLXREG_FAN_MAX_STATE)
- return -EINVAL;
- /* Save thermal state. */
- pwm->last_thermal_state = state;
- state = max_t(unsigned long, state, pwm->last_hwmon_state);
- err = regmap_write(fan->regmap, 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_pwm_connect_verify(struct mlxreg_fan *fan,
- struct mlxreg_core_data *data)
- {
- u32 regval;
- int err;
- err = regmap_read(fan->regmap, data->reg, ®val);
- if (err) {
- dev_err(fan->dev, "Failed to query pwm register 0x%08x\n",
- data->reg);
- return err;
- }
- return regval != MLXREG_FAN_PWM_NOT_CONNECTED;
- }
- 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)
- {
- int tacho_num = 0, tacho_avail = 0, pwm_num = 0, i;
- struct mlxreg_core_data *data = pdata->data;
- bool configured = false;
- 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].prsnt = data->reg_prsnt;
- fan->tacho[tacho_num++].connected = true;
- tacho_avail++;
- } else if (strnstr(data->label, "pwm", sizeof(data->label))) {
- if (pwm_num == MLXREG_FAN_MAX_TACHO) {
- dev_err(fan->dev, "too many pwm entries: %s\n",
- data->label);
- return -EINVAL;
- }
- /* Validate if more then one PWM is connected. */
- if (pwm_num) {
- err = mlxreg_pwm_connect_verify(fan, data);
- if (err < 0)
- return err;
- else if (!err)
- continue;
- }
- fan->pwm[pwm_num].reg = data->reg;
- fan->pwm[pwm_num].connected = true;
- pwm_num++;
- } 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;
- }
- }
- if (pdata->capability) {
- int drwr_avail;
- u32 regval;
- /* Obtain the number of FAN drawers, supported by system. */
- err = regmap_read(fan->regmap, pdata->capability, ®val);
- if (err) {
- dev_err(fan->dev, "Failed to query capability register 0x%08x\n",
- pdata->capability);
- return err;
- }
- drwr_avail = hweight32(regval);
- if (!tacho_avail || !drwr_avail || tacho_avail < drwr_avail) {
- dev_err(fan->dev, "Configuration is invalid: drawers num %d tachos num %d\n",
- drwr_avail, tacho_avail);
- return -EINVAL;
- }
- /* Set the number of tachometers per one drawer. */
- fan->tachos_per_drwr = tacho_avail / drwr_avail;
- }
- return 0;
- }
- static int mlxreg_fan_cooling_config(struct device *dev, struct mlxreg_fan *fan)
- {
- int i;
- for (i = 0; i < MLXREG_FAN_MAX_PWM; i++) {
- struct mlxreg_fan_pwm *pwm = &fan->pwm[i];
- if (!pwm->connected)
- continue;
- pwm->fan = fan;
- pwm->cdev = devm_thermal_of_cooling_device_register(dev, NULL, mlxreg_fan_name[i],
- pwm, &mlxreg_fan_cooling_ops);
- if (IS_ERR(pwm->cdev)) {
- dev_err(dev, "Failed to register cooling device\n");
- return PTR_ERR(pwm->cdev);
- }
- /* Set minimal PWM speed. */
- pwm->last_hwmon_state = MLXREG_FAN_PWM_DUTY2STATE(MLXREG_FAN_MIN_DUTY);
- }
- 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))
- err = mlxreg_fan_cooling_config(dev, fan);
- return err;
- }
- 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 <[email protected]>");
- MODULE_DESCRIPTION("Mellanox FAN driver");
- MODULE_LICENSE("GPL");
- MODULE_ALIAS("platform:mlxreg-fan");
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