diff options
Diffstat (limited to 'drivers/hwmon/emc2305.c')
| -rw-r--r-- | drivers/hwmon/emc2305.c | 738 |
1 files changed, 738 insertions, 0 deletions
diff --git a/drivers/hwmon/emc2305.c b/drivers/hwmon/emc2305.c new file mode 100644 index 000000000000..ceae96c07ac4 --- /dev/null +++ b/drivers/hwmon/emc2305.c @@ -0,0 +1,738 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Hardware monitoring driver for EMC2305 fan controller + * + * Copyright (C) 2022 Nvidia Technologies Ltd. + */ + +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/platform_data/emc2305.h> +#include <linux/thermal.h> +#include <linux/pwm.h> +#include <linux/of_device.h> +#include <linux/util_macros.h> + +#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27 +#define EMC2305_REG_VENDOR 0xfe +#define EMC2305_FAN_MAX 0xff +#define EMC2305_FAN_MIN 0x00 +#define EMC2305_FAN_MAX_STATE 10 +#define EMC2305_DEVICE 0x34 +#define EMC2305_VENDOR 0x5d +#define EMC2305_REG_PRODUCT_ID 0xfd +#define EMC2305_TACH_REGS_UNUSE_BITS 3 +#define EMC2305_TACH_CNT_MULTIPLIER 0x02 +#define EMC2305_TACH_RANGE_MIN 480 +#define EMC2305_DEFAULT_OUTPUT 0x0 +#define EMC2305_DEFAULT_POLARITY 0x0 +#define EMC2305_REG_POLARITY 0x2a +#define EMC2305_REG_DRIVE_PWM_OUT 0x2b +#define EMC2305_OPEN_DRAIN 0x0 +#define EMC2305_PUSH_PULL 0x1 + +#define EMC2305_PWM_DUTY2STATE(duty, max_state, pwm_max) \ + DIV_ROUND_CLOSEST((duty) * (max_state), (pwm_max)) +#define EMC2305_PWM_STATE2DUTY(state, max_state, pwm_max) \ + DIV_ROUND_CLOSEST((state) * (pwm_max), (max_state)) + +/* + * Factor by equations [2] and [3] from data sheet; valid for fans where the number of edges + * equal (poles * 2 + 1). + */ +#define EMC2305_RPM_FACTOR 3932160 + +#define EMC2305_REG_FAN_DRIVE(n) (0x30 + 0x10 * (n)) +#define EMC2305_REG_FAN_MIN_DRIVE(n) (0x38 + 0x10 * (n)) +#define EMC2305_REG_FAN_TACH(n) (0x3e + 0x10 * (n)) + +/* Supported base PWM frequencies */ +static const unsigned int base_freq_table[] = { 2441, 4882, 19530, 26000 }; + +enum emc230x_product_id { + EMC2305 = 0x34, + EMC2303 = 0x35, + EMC2302 = 0x36, + EMC2301 = 0x37, +}; + +static const struct i2c_device_id emc2305_ids[] = { + { "emc2305" }, + { "emc2303" }, + { "emc2302" }, + { "emc2301" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, emc2305_ids); + +/** + * struct emc2305_cdev_data - device-specific cooling device state + * @cdev: cooling device + * @cur_state: cooling current state + * @last_hwmon_state: last cooling state updated by hwmon subsystem + * @last_thermal_state: last cooling state updated by thermal subsystem + * + * The 'last_hwmon_state' and 'last_thermal_state' fields are provided to support fan low limit + * speed feature. The purpose of this feature is to provides ability to limit fan speed + * according to some system wise considerations, like absence of some replaceable units (PSU or + * line cards), high system ambient temperature, unreliable transceivers temperature sensing or + * some other factors which indirectly impacts system's airflow + * Fan low limit feature is supported through 'hwmon' interface: 'hwmon' 'pwm' attribute is + * used for setting low limit for fan speed in case 'thermal' subsystem is configured in + * kernel. In this case setting fan speed through 'hwmon' will never let the 'thermal' + * subsystem to select a lower duty cycle than the duty cycle selected with the 'pwm' + * attribute. + * From other side, fan speed is to be updated in hardware through 'pwm' only in case the + * requested fan speed is above last speed set by 'thermal' subsystem, otherwise requested fan + * speed will be just stored with no PWM update. + */ +struct emc2305_cdev_data { + struct thermal_cooling_device *cdev; + unsigned int cur_state; + unsigned long last_hwmon_state; + unsigned long last_thermal_state; +}; + +/** + * struct emc2305_data - device-specific data + * @client: i2c client + * @hwmon_dev: hwmon device + * @max_state: maximum cooling state of the cooling device + * @pwm_num: number of PWM channels + * @pwm_output_mask: PWM output mask + * @pwm_polarity_mask: PWM polarity mask + * @pwm_separate: separate PWM settings for every channel + * @pwm_min: array of minimum PWM per channel + * @pwm_freq: array of PWM frequency per channel + * @cdev_data: array of cooling devices data + */ +struct emc2305_data { + struct i2c_client *client; + struct device *hwmon_dev; + u8 max_state; + u8 pwm_num; + u8 pwm_output_mask; + u8 pwm_polarity_mask; + bool pwm_separate; + u8 pwm_min[EMC2305_PWM_MAX]; + u16 pwm_freq[EMC2305_PWM_MAX]; + struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX]; +}; + +static char *emc2305_fan_name[] = { + "emc2305_fan", + "emc2305_fan1", + "emc2305_fan2", + "emc2305_fan3", + "emc2305_fan4", + "emc2305_fan5", +}; + +static int emc2305_get_max_channel(const struct emc2305_data *data) +{ + return data->pwm_num; +} + +static int emc2305_get_cdev_idx(struct thermal_cooling_device *cdev) +{ + struct emc2305_data *data = cdev->devdata; + size_t len = strlen(cdev->type); + int ret; + + if (len <= 0) + return -EINVAL; + + /* + * Returns index of cooling device 0..4 in case of separate PWM setting. + * Zero index is used in case of one common PWM setting. + * If the mode is not set as pwm_separate, all PWMs are to be bound + * to the common thermal zone and should work at the same speed + * to perform cooling for the same thermal junction. + * Otherwise, return specific channel that will be used in bound + * related PWM to the thermal zone. + */ + if (!data->pwm_separate) + return 0; + + ret = cdev->type[len - 1]; + switch (ret) { + case '1' ... '5': + return ret - '1'; + default: + break; + } + return -EINVAL; +} + +static int emc2305_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state) +{ + int cdev_idx; + struct emc2305_data *data = cdev->devdata; + + cdev_idx = emc2305_get_cdev_idx(cdev); + if (cdev_idx < 0) + return cdev_idx; + + *state = data->cdev_data[cdev_idx].cur_state; + return 0; +} + +static int emc2305_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state) +{ + struct emc2305_data *data = cdev->devdata; + *state = data->max_state; + return 0; +} + +static int __emc2305_set_cur_state(struct emc2305_data *data, int cdev_idx, unsigned long state) +{ + int ret; + struct i2c_client *client = data->client; + u8 val, i; + + state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state); + + val = EMC2305_PWM_STATE2DUTY(state, data->max_state, EMC2305_FAN_MAX); + + data->cdev_data[cdev_idx].cur_state = state; + if (data->pwm_separate) { + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val); + if (ret < 0) + return ret; + } else { + /* + * Set the same PWM value in all channels + * if common PWM channel is used. + */ + for (i = 0; i < data->pwm_num; i++) { + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val); + if (ret < 0) + return ret; + } + } + + return 0; +} + +static int emc2305_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state) +{ + int cdev_idx, ret; + struct emc2305_data *data = cdev->devdata; + + if (state > data->max_state) + return -EINVAL; + + cdev_idx = emc2305_get_cdev_idx(cdev); + if (cdev_idx < 0) + return cdev_idx; + + /* Save thermal state. */ + data->cdev_data[cdev_idx].last_thermal_state = state; + ret = __emc2305_set_cur_state(data, cdev_idx, state); + if (ret < 0) + return ret; + + return 0; +} + +static const struct thermal_cooling_device_ops emc2305_cooling_ops = { + .get_max_state = emc2305_get_max_state, + .get_cur_state = emc2305_get_cur_state, + .set_cur_state = emc2305_set_cur_state, +}; + +static int emc2305_show_fault(struct device *dev, int channel) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int status_reg; + + status_reg = i2c_smbus_read_byte_data(client, EMC2305_REG_DRIVE_FAIL_STATUS); + if (status_reg < 0) + return status_reg; + + return status_reg & (1 << channel) ? 1 : 0; +} + +static int emc2305_show_fan(struct device *dev, int channel) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int ret; + + ret = i2c_smbus_read_word_swapped(client, EMC2305_REG_FAN_TACH(channel)); + if (ret <= 0) + return ret; + + ret = ret >> EMC2305_TACH_REGS_UNUSE_BITS; + ret = EMC2305_RPM_FACTOR / ret; + if (ret <= EMC2305_TACH_RANGE_MIN) + return 0; + + return ret * EMC2305_TACH_CNT_MULTIPLIER; +} + +static int emc2305_show_pwm(struct device *dev, int channel) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + + return i2c_smbus_read_byte_data(client, EMC2305_REG_FAN_DRIVE(channel)); +} + +static int emc2305_set_pwm(struct device *dev, long val, int channel) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + int ret; + + if (val < data->pwm_min[channel] || val > EMC2305_FAN_MAX) + return -EINVAL; + + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val); + if (ret < 0) + return ret; + data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state, + EMC2305_FAN_MAX); + return 0; +} + +static int emc2305_set_single_tz(struct device *dev, struct device_node *fan_node, int idx) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + long pwm; + int i, cdev_idx, ret; + + cdev_idx = (idx) ? idx - 1 : 0; + pwm = data->pwm_min[cdev_idx]; + + data->cdev_data[cdev_idx].cdev = + devm_thermal_of_cooling_device_register(dev, fan_node, + emc2305_fan_name[idx], data, + &emc2305_cooling_ops); + + if (IS_ERR(data->cdev_data[cdev_idx].cdev)) { + dev_err(dev, "Failed to register cooling device %s\n", emc2305_fan_name[idx]); + return PTR_ERR(data->cdev_data[cdev_idx].cdev); + } + + if (data->cdev_data[cdev_idx].cur_state > 0) + /* Update pwm when temperature is above trips */ + pwm = EMC2305_PWM_STATE2DUTY(data->cdev_data[cdev_idx].cur_state, + data->max_state, EMC2305_FAN_MAX); + + /* Set minimal PWM speed. */ + if (data->pwm_separate) { + ret = emc2305_set_pwm(dev, pwm, cdev_idx); + if (ret < 0) + return ret; + } else { + for (i = 0; i < data->pwm_num; i++) { + ret = emc2305_set_pwm(dev, pwm, i); + if (ret < 0) + return ret; + } + } + data->cdev_data[cdev_idx].cur_state = + EMC2305_PWM_DUTY2STATE(pwm, data->max_state, + EMC2305_FAN_MAX); + data->cdev_data[cdev_idx].last_hwmon_state = + EMC2305_PWM_DUTY2STATE(pwm, data->max_state, + EMC2305_FAN_MAX); + return 0; +} + +static int emc2305_set_tz(struct device *dev) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + int i, ret; + + if (!data->pwm_separate) + return emc2305_set_single_tz(dev, dev->of_node, 0); + + for (i = 0; i < data->pwm_num; i++) { + ret = emc2305_set_single_tz(dev, dev->of_node, i + 1); + if (ret) + return ret; + } + return 0; +} + +static umode_t +emc2305_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) +{ + int max_channel = emc2305_get_max_channel(data); + + /* Don't show channels which are not physically connected. */ + if (channel >= max_channel) + return 0; + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + return 0444; + case hwmon_fan_fault: + return 0444; + default: + break; + } + break; + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + return 0644; + default: + break; + } + break; + default: + break; + } + + return 0; +}; + +static int +emc2305_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + int cdev_idx; + + switch (type) { + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + /* If thermal is configured - handle PWM limit setting. */ + if (IS_REACHABLE(CONFIG_THERMAL)) { + if (data->pwm_separate) + cdev_idx = channel; + else + cdev_idx = 0; + data->cdev_data[cdev_idx].last_hwmon_state = + EMC2305_PWM_DUTY2STATE(val, data->max_state, + EMC2305_FAN_MAX); + /* + * Update PWM only in case requested state is not less than the + * last thermal state. + */ + if (data->cdev_data[cdev_idx].last_hwmon_state >= + data->cdev_data[cdev_idx].last_thermal_state) + return __emc2305_set_cur_state(data, cdev_idx, + data->cdev_data[cdev_idx].last_hwmon_state); + return 0; + } + return emc2305_set_pwm(dev, val, channel); + default: + break; + } + break; + default: + break; + } + + return -EOPNOTSUPP; +}; + +static int +emc2305_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) +{ + int ret; + + switch (type) { + case hwmon_fan: + switch (attr) { + case hwmon_fan_input: + ret = emc2305_show_fan(dev, channel); + if (ret < 0) + return ret; + *val = ret; + return 0; + case hwmon_fan_fault: + ret = emc2305_show_fault(dev, channel); + if (ret < 0) + return ret; + *val = ret; + return 0; + default: + break; + } + break; + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + ret = emc2305_show_pwm(dev, channel); + if (ret < 0) + return ret; + *val = ret; + return 0; + default: + break; + } + break; + default: + break; + } + + return -EOPNOTSUPP; +}; + +static const struct hwmon_ops emc2305_ops = { + .is_visible = emc2305_is_visible, + .read = emc2305_read, + .write = emc2305_write, +}; + +static const struct hwmon_channel_info * const emc2305_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_CHANNEL_INFO(pwm, + HWMON_PWM_INPUT, + HWMON_PWM_INPUT, + HWMON_PWM_INPUT, + HWMON_PWM_INPUT, + HWMON_PWM_INPUT), + NULL +}; + +static const struct hwmon_chip_info emc2305_chip_info = { + .ops = &emc2305_ops, + .info = emc2305_info, +}; + +static int emc2305_identify(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct emc2305_data *data = i2c_get_clientdata(client); + int ret; + + ret = i2c_smbus_read_byte_data(client, EMC2305_REG_PRODUCT_ID); + if (ret < 0) + return ret; + + switch (ret) { + case EMC2305: + data->pwm_num = 5; + break; + case EMC2303: + data->pwm_num = 3; + break; + case EMC2302: + data->pwm_num = 2; + break; + case EMC2301: + data->pwm_num = 1; + break; + default: + return -ENODEV; + } + + return 0; +} + +static int emc2305_of_parse_pwm_child(struct device *dev, + struct device_node *child, + struct emc2305_data *data) +{ u32 ch; + int ret; + struct of_phandle_args args; + + ret = of_property_read_u32(child, "reg", &ch); + if (ret) { + dev_err(dev, "missing reg property of %pOFn\n", child); + return ret; + } + + ret = of_parse_phandle_with_args(child, "pwms", "#pwm-cells", 0, &args); + + if (ret) + return ret; + + if (args.args_count > 0) { + data->pwm_freq[ch] = find_closest(args.args[0], base_freq_table, + ARRAY_SIZE(base_freq_table)); + } else { + data->pwm_freq[ch] = base_freq_table[3]; + } + + if (args.args_count > 1) { + if (args.args[1] == PWM_POLARITY_NORMAL || args.args[1] == PWM_POLARITY_INVERSED) + data->pwm_polarity_mask |= args.args[1] << ch; + else + dev_err(dev, "Wrong PWM polarity config provided: %d\n", args.args[0]); + } else { + data->pwm_polarity_mask |= PWM_POLARITY_NORMAL << ch; + } + + if (args.args_count > 2) { + if (args.args[2] == EMC2305_PUSH_PULL || args.args[2] <= EMC2305_OPEN_DRAIN) + data->pwm_output_mask |= args.args[2] << ch; + else + dev_err(dev, "Wrong PWM output config provided: %d\n", args.args[1]); + } else { + data->pwm_output_mask |= EMC2305_OPEN_DRAIN << ch; + } + + return 0; +} + +static int emc2305_probe_childs_from_dt(struct device *dev) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + struct device_node *child; + int ret, count = 0; + + data->pwm_output_mask = 0x0; + data->pwm_polarity_mask = 0x0; + + for_each_child_of_node(dev->of_node, child) { + if (of_property_present(child, "reg")) { + ret = emc2305_of_parse_pwm_child(dev, child, data); + if (ret) + continue; + count++; + } + } + return count; +} + +static int emc2305_probe(struct i2c_client *client) +{ + struct i2c_adapter *adapter = client->adapter; + struct device *dev = &client->dev; + struct device_node *child; + struct emc2305_data *data; + struct emc2305_platform_data *pdata; + int vendor; + int ret; + int i; + int pwm_childs; + + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) + return -ENODEV; + + vendor = i2c_smbus_read_byte_data(client, EMC2305_REG_VENDOR); + if (vendor != EMC2305_VENDOR) + return -ENODEV; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + i2c_set_clientdata(client, data); + data->client = client; + + ret = emc2305_identify(dev); + if (ret) + return ret; + + pwm_childs = emc2305_probe_childs_from_dt(dev); + + pdata = dev_get_platdata(&client->dev); + + if (!pwm_childs) { + if (pdata) { + if (!pdata->max_state || pdata->max_state > EMC2305_FAN_MAX_STATE) + return -EINVAL; + data->max_state = pdata->max_state; + /* + * Validate a number of active PWM channels. Note that + * configured number can be less than the actual maximum + * supported by the device. + */ + if (!pdata->pwm_num || pdata->pwm_num > EMC2305_PWM_MAX) + return -EINVAL; + data->pwm_num = pdata->pwm_num; + data->pwm_output_mask = pdata->pwm_output_mask; + data->pwm_polarity_mask = pdata->pwm_polarity_mask; + data->pwm_separate = pdata->pwm_separate; + for (i = 0; i < EMC2305_PWM_MAX; i++) { + data->pwm_min[i] = pdata->pwm_min[i]; + data->pwm_freq[i] = pdata->pwm_freq[i]; + } + } else { + data->max_state = EMC2305_FAN_MAX_STATE; + data->pwm_separate = false; + data->pwm_output_mask = EMC2305_DEFAULT_OUTPUT; + data->pwm_polarity_mask = EMC2305_DEFAULT_POLARITY; + for (i = 0; i < EMC2305_PWM_MAX; i++) { + data->pwm_min[i] = EMC2305_FAN_MIN; + data->pwm_freq[i] = base_freq_table[3]; + } + } + } else { + data->max_state = EMC2305_FAN_MAX_STATE; + data->pwm_separate = false; + for (i = 0; i < EMC2305_PWM_MAX; i++) + data->pwm_min[i] = EMC2305_FAN_MIN; + } + + data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "emc2305", data, + &emc2305_chip_info, NULL); + if (IS_ERR(data->hwmon_dev)) + return PTR_ERR(data->hwmon_dev); + + if (IS_REACHABLE(CONFIG_THERMAL)) { + /* Parse and check for the available PWM child nodes */ + if (pwm_childs > 0) { + i = 0; + for_each_child_of_node(dev->of_node, child) { + ret = emc2305_set_single_tz(dev, child, i); + if (ret != 0) { + of_node_put(child); + return ret; + } + i++; + } + } else { + ret = emc2305_set_tz(dev); + if (ret != 0) + return ret; + } + } + + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_DRIVE_PWM_OUT, + data->pwm_output_mask); + if (ret < 0) + dev_err(dev, "Failed to configure pwm output, using default\n"); + + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_POLARITY, + data->pwm_polarity_mask); + if (ret < 0) + dev_err(dev, "Failed to configure pwm polarity, using default\n"); + + for (i = 0; i < data->pwm_num; i++) { + ret = i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i), + data->pwm_min[i]); + if (ret < 0) + return ret; + } + + return 0; +} + +static const struct of_device_id of_emc2305_match_table[] = { + { .compatible = "microchip,emc2305", }, + {}, +}; +MODULE_DEVICE_TABLE(of, of_emc2305_match_table); + +static struct i2c_driver emc2305_driver = { + .driver = { + .name = "emc2305", + .of_match_table = of_emc2305_match_table, + }, + .probe = emc2305_probe, + .id_table = emc2305_ids, +}; + +module_i2c_driver(emc2305_driver); + +MODULE_AUTHOR("Nvidia"); +MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver"); +MODULE_LICENSE("GPL"); |