// 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 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; *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 <vadimp@mellanox.com>"); MODULE_DESCRIPTION("Mellanox FAN driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:mlxreg-fan");