// 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_DIVIDER_DEF 1132 /* * 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 u32 mlxreg_fan_hwmon_fan_config[] = { 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, 0 }; static const struct hwmon_channel_info mlxreg_fan_hwmon_fan = { .type = hwmon_fan, .config = mlxreg_fan_hwmon_fan_config, }; static const u32 mlxreg_fan_hwmon_pwm_config[] = { HWMON_PWM_INPUT, 0 }; static const struct hwmon_channel_info mlxreg_fan_hwmon_pwm = { .type = hwmon_pwm, .config = mlxreg_fan_hwmon_pwm_config, }; static const struct hwmon_channel_info *mlxreg_fan_hwmon_info[] = { &mlxreg_fan_hwmon_fan, &mlxreg_fan_hwmon_pwm, 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_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; fan->samples = MLXREG_FAN_TACHO_SAMPLES_PER_PULSE_DEF; fan->divider = MLXREG_FAN_TACHO_DIVIDER_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; } 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) { dev_err(fan->dev, "invalid conf entry params: %s\n", data->label); return -EINVAL; } fan->samples = data->mask; 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 mlxreg_fan *fan; struct device *hwm; int err; pdata = dev_get_platdata(&pdev->dev); if (!pdata) { dev_err(&pdev->dev, "Failed to get platform data.\n"); return -EINVAL; } fan = devm_kzalloc(&pdev->dev, sizeof(*fan), GFP_KERNEL); if (!fan) return -ENOMEM; fan->dev = &pdev->dev; fan->regmap = pdata->regmap; platform_set_drvdata(pdev, fan); err = mlxreg_fan_config(fan, pdata); if (err) return err; hwm = devm_hwmon_device_register_with_info(&pdev->dev, "mlxreg_fan", fan, &mlxreg_fan_hwmon_chip_info, NULL); if (IS_ERR(hwm)) { dev_err(&pdev->dev, "Failed to register hwmon device\n"); return PTR_ERR(hwm); } if (IS_REACHABLE(CONFIG_THERMAL)) { fan->cdev = thermal_cooling_device_register("mlxreg_fan", fan, &mlxreg_fan_cooling_ops); if (IS_ERR(fan->cdev)) { dev_err(&pdev->dev, "Failed to register cooling device\n"); return PTR_ERR(fan->cdev); } } return 0; } static int mlxreg_fan_remove(struct platform_device *pdev) { struct mlxreg_fan *fan = platform_get_drvdata(pdev); if (IS_REACHABLE(CONFIG_THERMAL)) thermal_cooling_device_unregister(fan->cdev); return 0; } static struct platform_driver mlxreg_fan_driver = { .driver = { .name = "mlxreg-fan", }, .probe = mlxreg_fan_probe, .remove = mlxreg_fan_remove, }; 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");