diff options
Diffstat (limited to 'drivers/hwmon/mlxreg-fan.c')
| -rw-r--r-- | drivers/hwmon/mlxreg-fan.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/drivers/hwmon/mlxreg-fan.c b/drivers/hwmon/mlxreg-fan.c new file mode 100644 index 000000000..052c897a6 --- /dev/null +++ b/drivers/hwmon/mlxreg-fan.c @@ -0,0 +1,535 @@ +// 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; + + 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: + 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; + int i, config = 0; + u32 regval; + 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) { + /* + * This is configuration change, which is only supported through sysfs. + * For configuration non-zero value is to be returned to avoid thermal + * statistics update. + */ + config = 1; + 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 config; + + 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 config; +} + +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"); |