| Message ID | 20220430114905.53448-2-michaelsh@nvidia.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | Add support for EMC2305 Fan Speed Controller. | expand |
On Sat, Apr 30, 2022 at 02:49:03PM +0300, michaelsh@nvidia.com wrote: > From: Michael Shych <michaelsh@nvidia.com> > > Add driver for Microchip EMC2301/2/3/5 RPM-based PWM Fan Speed Controller. > Modify Makefile and Kconfig to support Microchip EMC2305 RPM-based > PWM Fan Speed Controller. > > Signed-off-by: Michael Shych <michaelsh@nvidia.com> > Reviewed-by: Vadim Pasternak <vadimp@nvidia.com> > --- > drivers/hwmon/Kconfig | 13 + > drivers/hwmon/Makefile | 1 + > drivers/hwmon/emc2305.c | 629 ++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 643 insertions(+) > create mode 100644 drivers/hwmon/emc2305.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 85c22bba439b..3c25ba0e6ef7 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1750,6 +1750,19 @@ config SENSORS_EMC2103 > This driver can also be built as a module. If so, the module > will be called emc2103. > > +config SENSORS_EMC2305 > + tristate "Microchip EMC2305 and compatible EMC2301/2/3" > + depends on I2C > + imply THERMAL > + help > + If you say yes here you get support for the Microchip EMC2305 > + fan controller chips. > + The Microchip EMC2305 is a fan controller for up to 5 fans. > + Fan rotation speeds are reported in RPM. > + > + This driver can also be built as a module. If so, the module > + will be called emc2305. > + > config SENSORS_EMC6W201 > tristate "SMSC EMC6W201" > depends on I2C > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 93f2b774cc5e..e2238c207ef4 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -70,6 +70,7 @@ obj-$(CONFIG_SENSORS_DS620) += ds620.o > obj-$(CONFIG_SENSORS_DS1621) += ds1621.o > obj-$(CONFIG_SENSORS_EMC1403) += emc1403.o > obj-$(CONFIG_SENSORS_EMC2103) += emc2103.o > +obj-$(CONFIG_SENSORS_EMC2305) += emc2305.o > obj-$(CONFIG_SENSORS_EMC6W201) += emc6w201.o > obj-$(CONFIG_SENSORS_F71805F) += f71805f.o > obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o > diff --git a/drivers/hwmon/emc2305.c b/drivers/hwmon/emc2305.c > new file mode 100644 > index 000000000000..5c896fdfc525 > --- /dev/null > +++ b/drivers/hwmon/emc2305.c > @@ -0,0 +1,629 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * Hardware monitoring driver for EMC2305 fan controller > + * > + * Copyright (C) 2022 Nvidia Technologies Ltd and Delta Networks, Inc. > + */ > + > +#include <linux/err.h> > +#include <linux/hwmon.h> > +#include <linux/hwmon-sysfs.h> Not necessary > +#include <linux/i2c.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/thermal.h> > +#include <linux/version.h> > + > +static const unsigned short > +emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END }; > + > +#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27 > +#define EMC2305_REG_DEVICE 0xfd > +#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_PWM_MAX 5 > +#define EMC2305_PWM_CHNL_CMN 0 > + > +#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). > + */ /* * Please use standard multi-line comments. */ > +#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)) Please use #define<space>NAME<tab>value > + > +enum emc230x_product_id { > + EMC2305 = 0x34, > + EMC2303 = 0x35, > + EMC2302 = 0x36, > + EMC2301 = 0x37, > +}; > + > +static const struct i2c_device_id emc2305_ids[] = { > + { "emc2305", 0 }, > + { "emc2303", 0 }, > + { "emc2302", 0 }, > + { "emc2301", 0 }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, emc2305_ids); > + > +static const struct of_device_id emc2305_dt_ids[] = { > + { .compatible = "smsc,emc2305" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, emc2305_dt_ids); > + > +/** > + * @cdev: cooling device; > + * @curr_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; > +}; > + > +/** > + * @client: i2c client; > + * @hwmon_dev: hwmon device; > + * @max_state: maximum cooling state of the cooling device; > + * @pwm_max: maximum PWM; > + * @pwm_min: minimum PWM; > + * @pwm_channel: maximum number of PWM channels; > + * @cdev_data: array of cooling devices data; > + */ > +struct emc2305_data { > + struct i2c_client *client; > + struct device *hwmon_dev; > + u8 max_state; > + u8 pwm_max; > + u8 pwm_min; > + u8 pwm_num; > + u8 pwm_channel; > + 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(struct emc2305_data *data) > +{ > + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) > + return data->pwm_num; > + else else after return is unnecessary > + return data->pwm_channel; > +} > + > +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; > + > + /* Retuns 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 set as EMC2305_PWM_CHNL_CMN, 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_channel == EMC2305_PWM_CHNL_CMN) > + 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 thermal_cooling_device *cdev, unsigned long state) > +{ > + int cdev_idx; > + struct emc2305_data *data = cdev->devdata; > + struct i2c_client *client = data->client; > + u8 val, i; > + > + 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; > + state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state); > + > + val = EMC2305_PWM_STATE2DUTY(state, data->max_state, data->pwm_max); > + if (val > EMC2305_FAN_MAX) > + return -EINVAL; > + > + data->cdev_data[cdev_idx].cur_state = state; > + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) > + /* Set the same PWM value in all channels > + * if common PWM channel is used. > + */ > + for (i = 0; i < data->pwm_num; i++) > + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val); > + else > + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val); > + > + 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); > + 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; > + return EMC2305_RPM_FACTOR * EMC2305_TACH_CNT_MULTIPLIER / (ret > 0 ? ret : 1); > +} > + > +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; > + > + if (val < data->pwm_min || val > data->pwm_max) > + return -EINVAL; > + > + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val); > + data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state, > + data->pwm_max); > + return 0; > +} > + > +static int emc2305_get_tz_of(struct device *dev) > +{ > + struct device_node *np = dev->of_node; > + struct emc2305_data *data = dev_get_drvdata(dev); > + int ret = 0; > + > + /* OF parameters are optional - overwrite default setting > + * if some of them are provided. > + */ > + > + if (of_find_property(np, "emc2305,cooling-levels", NULL)) { > + ret = of_property_read_u8(np, "emc2305,cooling-levels", &data->max_state); > + if (ret) > + return ret; > + } > + > + if (of_find_property(np, "emc2305,pwm-max", NULL)) { > + ret = of_property_read_u8(np, "emc2305,pwm-max", &data->pwm_max); > + if (ret) > + return ret; > + } > + > + if (of_find_property(np, "emc2305,pwm-min", NULL)) { > + ret = of_property_read_u8(np, "emc2305,pwm-min", &data->pwm_min); > + if (ret) > + return ret; > + } > + > + /* Not defined or 0 means one thermal zone over all colling devices. cooling > + * Otherwise - separted thermal zones for each PWM channel. separate ? > + */ > + if (of_find_property(np, "emc2305,pwm-channel", NULL)) { > + ret = of_property_read_u8(np, "emc2305,pwm-channel", &data->pwm_channel); > + if (ret) > + return ret; > + } I think those values should be validated. > + > + return ret; > +} > + > +static int emc2305_set_single_tz(struct device *dev, int idx) > +{ > + struct emc2305_data *data = dev_get_drvdata(dev); > + long pwm = data->pwm_max; > + int cdev_idx; > + > + cdev_idx = (idx) ? idx - 1 : 0; > + > + if (dev->of_node) > + data->cdev_data[cdev_idx].cdev = > + devm_thermal_of_cooling_device_register(dev, dev->of_node, > + emc2305_fan_name[idx], data, > + &emc2305_cooling_ops); > + else > + data->cdev_data[cdev_idx].cdev = > + thermal_cooling_device_register(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); > + } > + emc2305_set_pwm(dev, pwm, cdev_idx); > + data->cdev_data[cdev_idx].cur_state = data->max_state; > + /* Set minimal PWM speed. */ > + data->cdev_data[cdev_idx].last_hwmon_state = EMC2305_PWM_DUTY2STATE(data->pwm_min, > + data->max_state, > + data->pwm_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_channel == EMC2305_PWM_CHNL_CMN) > + return emc2305_set_single_tz(dev, 0); > + > + for (i = 0; i < data->pwm_channel; i++) { > + ret = emc2305_set_single_tz(dev, i + 1); > + if (ret) > + goto thermal_cooling_device_register_fail; > + } > + return 0; > + > +thermal_cooling_device_register_fail: > + emc2305_unset_tz(dev); > + return ret; > +} > + > +static void emc2305_unset_tz(struct device *dev) > +{ > + struct emc2305_data *data = dev_get_drvdata(dev); > + int i; > + > + /* Unregister cooling device in case they have been registered by > + * thermal_cooling_device_unregister(). No need for clean-up flow in case they > + * have been registered by devm_thermal_of_cooling_device_register() > + */ > + if (!dev->of_node) { > + for (i = 0; i < EMC2305_PWM_MAX; i++) > + if (data->cdev_data[i].cdev) > + thermal_cooling_device_unregister(data->cdev_data[i].cdev); > + } > +} > + > +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((struct emc2305_data *)data); Unnecessary typecast. > + > + /* Don't show channels which are not physically connected. */ > + if ((channel + 1) > max_channel) Unnecessary () > + 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); > + > + switch (type) { > + case hwmon_pwm: > + switch (attr) { > + case hwmon_pwm_input: > + /* If thermal is configured - handle PWM limit setting. */ > + if (IS_REACHABLE(CONFIG_THERMAL)) { > + data->cdev_data[channel].last_hwmon_state = > + EMC2305_PWM_DUTY2STATE(val, data->max_state, data->pwm_max); > + /* Update PWM only in case requested state is not less than the > + * last thermal state. > + */ > + if (data->cdev_data[channel].last_hwmon_state >= > + data->cdev_data[channel].last_thermal_state) > + return emc2305_set_cur_state(data->cdev_data[channel].cdev, > + data->cdev_data[channel].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 *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 -EINVAL; > + } > + > + return 0; > +} > + > +static int emc2305_probe(struct i2c_client *client, const struct i2c_device_id *id) > +{ > + struct i2c_adapter *adapter = client->adapter; > + struct device *dev = &client->dev; > + struct emc2305_data *data; > + int vendor, device; > + int ret; > + int i; > + > + 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; > + > + device = i2c_smbus_read_byte_data(client, EMC2305_REG_DEVICE); > + if (device != EMC2305_DEVICE) > + 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; > + > + data->max_state = EMC2305_FAN_MAX_STATE; > + data->pwm_max = EMC2305_FAN_MAX; > + data->pwm_min = EMC2305_FAN_MIN; > + data->pwm_channel = EMC2305_PWM_CHNL_CMN; > + if (dev->of_node) { > + ret = emc2305_get_tz_of(dev); > + if (ret < 0) > + return ret; > + } > + > + 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)) { > + ret = emc2305_set_tz(dev); > + if (ret != 0) > + return ret; > + } > + > + for (i = 0; i < data->pwm_num; i++) > + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i), data->pwm_min); > + > + return 0; > +} > + > +static int emc2305_remove(struct i2c_client *client) > +{ > + struct device *dev = &client->dev; > + > + if (IS_REACHABLE(CONFIG_THERMAL)) > + emc2305_unset_tz(dev); It would be desirable to handle this with devm_add_action_or_reset() from emc2305_set_tz(). > + return 0; > +} > + > +static struct i2c_driver emc2305_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "emc2305", > + .of_match_table = emc2305_dt_ids, > + }, > + .probe = emc2305_probe, > + .remove = emc2305_remove, > + .id_table = emc2305_ids, > + .address_list = emc2305_normal_i2c, > +}; > + > +module_i2c_driver(emc2305_driver); > + > +MODULE_AUTHOR("Nvidia"); > +MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver"); > +MODULE_LICENSE("GPL"); > -- > 2.14.1 >
> -----Original Message----- > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck > Sent: Saturday, April 30, 2022 3:57 PM > To: Michael Shych <michaelsh@nvidia.com> > Cc: robh+dt@kernel.org; linux-hwmon@vger.kernel.org; > devicetree@vger.kernel.org; Vadim Pasternak <vadimp@nvidia.com> > Subject: Re: [PATCH v1 1/3] hwmon: (emc2305) add support for > EMC2301/2/3/5 RPM-based PWM Fan Speed Controller. > > On Sat, Apr 30, 2022 at 02:49:03PM +0300, michaelsh@nvidia.com wrote: > > From: Michael Shych <michaelsh@nvidia.com> > > > > Add driver for Microchip EMC2301/2/3/5 RPM-based PWM Fan Speed > Controller. > > Modify Makefile and Kconfig to support Microchip EMC2305 RPM-based > PWM > > Fan Speed Controller. > > > > Signed-off-by: Michael Shych <michaelsh@nvidia.com> > > Reviewed-by: Vadim Pasternak <vadimp@nvidia.com> > > --- > > drivers/hwmon/Kconfig | 13 + > > drivers/hwmon/Makefile | 1 + > > drivers/hwmon/emc2305.c | 629 > > ++++++++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 643 insertions(+) > > create mode 100644 drivers/hwmon/emc2305.c > > > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index > > 85c22bba439b..3c25ba0e6ef7 100644 > > --- a/drivers/hwmon/Kconfig > > +++ b/drivers/hwmon/Kconfig > > @@ -1750,6 +1750,19 @@ config SENSORS_EMC2103 > > This driver can also be built as a module. If so, the module > > will be called emc2103. > > > > +config SENSORS_EMC2305 > > + tristate "Microchip EMC2305 and compatible EMC2301/2/3" > > + depends on I2C > > + imply THERMAL > > + help > > + If you say yes here you get support for the Microchip EMC2305 > > + fan controller chips. > > + The Microchip EMC2305 is a fan controller for up to 5 fans. > > + Fan rotation speeds are reported in RPM. > > + > > + This driver can also be built as a module. If so, the module > > + will be called emc2305. > > + > > config SENSORS_EMC6W201 > > tristate "SMSC EMC6W201" > > depends on I2C > > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index > > 93f2b774cc5e..e2238c207ef4 100644 > > --- a/drivers/hwmon/Makefile > > +++ b/drivers/hwmon/Makefile > > @@ -70,6 +70,7 @@ obj-$(CONFIG_SENSORS_DS620) += ds620.o > > obj-$(CONFIG_SENSORS_DS1621) += ds1621.o > > obj-$(CONFIG_SENSORS_EMC1403) += emc1403.o > > obj-$(CONFIG_SENSORS_EMC2103) += emc2103.o > > +obj-$(CONFIG_SENSORS_EMC2305) += emc2305.o > > obj-$(CONFIG_SENSORS_EMC6W201) += emc6w201.o > > obj-$(CONFIG_SENSORS_F71805F) += f71805f.o > > obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o > > diff --git a/drivers/hwmon/emc2305.c b/drivers/hwmon/emc2305.c new > > file mode 100644 index 000000000000..5c896fdfc525 > > --- /dev/null > > +++ b/drivers/hwmon/emc2305.c > > @@ -0,0 +1,629 @@ > > +// SPDX-License-Identifier: GPL-2.0+ > > +/* > > + * Hardware monitoring driver for EMC2305 fan controller > > + * > > + * Copyright (C) 2022 Nvidia Technologies Ltd and Delta Networks, Inc. > > + */ > > + > > +#include <linux/err.h> > > +#include <linux/hwmon.h> > > +#include <linux/hwmon-sysfs.h> > > Not necessary Removed. > > > +#include <linux/i2c.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/thermal.h> > > +#include <linux/version.h> > > + > > +static const unsigned short > > +emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, > > +I2C_CLIENT_END }; > > + > > +#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27 > > +#define EMC2305_REG_DEVICE 0xfd > > +#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_PWM_MAX 5 > > +#define EMC2305_PWM_CHNL_CMN 0 > > + > > +#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). > > + */ > > /* > * Please use standard multi-line comments. > */ Ack. > > > +#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)) > > Please use > > #define<space>NAME<tab>value > Ack. > > + > > +enum emc230x_product_id { > > + EMC2305 = 0x34, > > + EMC2303 = 0x35, > > + EMC2302 = 0x36, > > + EMC2301 = 0x37, > > +}; > > + > > +static const struct i2c_device_id emc2305_ids[] = { > > + { "emc2305", 0 }, > > + { "emc2303", 0 }, > > + { "emc2302", 0 }, > > + { "emc2301", 0 }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(i2c, emc2305_ids); > > + > > +static const struct of_device_id emc2305_dt_ids[] = { > > + { .compatible = "smsc,emc2305" }, > > + { } > > +}; > > +MODULE_DEVICE_TABLE(of, emc2305_dt_ids); > > + > > +/** > > + * @cdev: cooling device; > > + * @curr_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; > > +}; > > + > > +/** > > + * @client: i2c client; > > + * @hwmon_dev: hwmon device; > > + * @max_state: maximum cooling state of the cooling device; > > + * @pwm_max: maximum PWM; > > + * @pwm_min: minimum PWM; > > + * @pwm_channel: maximum number of PWM channels; > > + * @cdev_data: array of cooling devices data; */ struct emc2305_data > > +{ > > + struct i2c_client *client; > > + struct device *hwmon_dev; > > + u8 max_state; > > + u8 pwm_max; > > + u8 pwm_min; > > + u8 pwm_num; > > + u8 pwm_channel; > > + 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(struct emc2305_data *data) { > > + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) > > + return data->pwm_num; > > + else > > else after return is unnecessary Changed. > > > + return data->pwm_channel; > > +} > > + > > +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; > > + > > + /* Retuns 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 set as EMC2305_PWM_CHNL_CMN, 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_channel == EMC2305_PWM_CHNL_CMN) > > + 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 thermal_cooling_device *cdev, > > +unsigned long state) { > > + int cdev_idx; > > + struct emc2305_data *data = cdev->devdata; > > + struct i2c_client *client = data->client; > > + u8 val, i; > > + > > + 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; > > + state = max_t(unsigned long, state, > > +data->cdev_data[cdev_idx].last_hwmon_state); > > + > > + val = EMC2305_PWM_STATE2DUTY(state, data->max_state, data- > >pwm_max); > > + if (val > EMC2305_FAN_MAX) > > + return -EINVAL; > > + > > + data->cdev_data[cdev_idx].cur_state = state; > > + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) > > + /* Set the same PWM value in all channels > > + * if common PWM channel is used. > > + */ > > + for (i = 0; i < data->pwm_num; i++) > > + i2c_smbus_write_byte_data(client, > EMC2305_REG_FAN_DRIVE(i), val); > > + else > > + i2c_smbus_write_byte_data(client, > EMC2305_REG_FAN_DRIVE(cdev_idx), > > +val); > > + > > + 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); > > + 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; > > + return EMC2305_RPM_FACTOR * EMC2305_TACH_CNT_MULTIPLIER > / (ret > 0 ? > > +ret : 1); } > > + > > +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; > > + > > + if (val < data->pwm_min || val > data->pwm_max) > > + return -EINVAL; > > + > > + i2c_smbus_write_byte_data(client, > EMC2305_REG_FAN_DRIVE(channel), val); > > + data->cdev_data[channel].cur_state = > EMC2305_PWM_DUTY2STATE(val, data->max_state, > > + data- > >pwm_max); > > + return 0; > > +} > > + > > +static int emc2305_get_tz_of(struct device *dev) { > > + struct device_node *np = dev->of_node; > > + struct emc2305_data *data = dev_get_drvdata(dev); > > + int ret = 0; > > + > > + /* OF parameters are optional - overwrite default setting > > + * if some of them are provided. > > + */ > > + > > + if (of_find_property(np, "emc2305,cooling-levels", NULL)) { > > + ret = of_property_read_u8(np, "emc2305,cooling-levels", > &data->max_state); > > + if (ret) > > + return ret; > > + } > > + > > + if (of_find_property(np, "emc2305,pwm-max", NULL)) { > > + ret = of_property_read_u8(np, "emc2305,pwm-max", &data- > >pwm_max); > > + if (ret) > > + return ret; > > + } > > + > > + if (of_find_property(np, "emc2305,pwm-min", NULL)) { > > + ret = of_property_read_u8(np, "emc2305,pwm-min", &data- > >pwm_min); > > + if (ret) > > + return ret; > > + } > > + > > + /* Not defined or 0 means one thermal zone over all colling devices. > > cooling Changed. > > > + * Otherwise - separted thermal zones for each PWM channel. > > separate ? > > > + */ > > + if (of_find_property(np, "emc2305,pwm-channel", NULL)) { > > + ret = of_property_read_u8(np, "emc2305,pwm-channel", > &data->pwm_channel); > > + if (ret) > > + return ret; > > + } > > I think those values should be validated. Checks are added. > > > + > > + return ret; > > +} > > + > > +static int emc2305_set_single_tz(struct device *dev, int idx) { > > + struct emc2305_data *data = dev_get_drvdata(dev); > > + long pwm = data->pwm_max; > > + int cdev_idx; > > + > > + cdev_idx = (idx) ? idx - 1 : 0; > > + > > + if (dev->of_node) > > + data->cdev_data[cdev_idx].cdev = > > + devm_thermal_of_cooling_device_register(dev, dev- > >of_node, > > + > emc2305_fan_name[idx], data, > > + > &emc2305_cooling_ops); > > + else > > + data->cdev_data[cdev_idx].cdev = > > + > thermal_cooling_device_register(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); > > + } > > + emc2305_set_pwm(dev, pwm, cdev_idx); > > + data->cdev_data[cdev_idx].cur_state = data->max_state; > > + /* Set minimal PWM speed. */ > > + data->cdev_data[cdev_idx].last_hwmon_state = > EMC2305_PWM_DUTY2STATE(data->pwm_min, > > + > data->max_state, > > + > data->pwm_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_channel == EMC2305_PWM_CHNL_CMN) > > + return emc2305_set_single_tz(dev, 0); > > + > > + for (i = 0; i < data->pwm_channel; i++) { > > + ret = emc2305_set_single_tz(dev, i + 1); > > + if (ret) > > + goto thermal_cooling_device_register_fail; > > + } > > + return 0; > > + > > +thermal_cooling_device_register_fail: > > + emc2305_unset_tz(dev); > > + return ret; > > +} > > + > > +static void emc2305_unset_tz(struct device *dev) { > > + struct emc2305_data *data = dev_get_drvdata(dev); > > + int i; > > + > > + /* Unregister cooling device in case they have been registered by > > + * thermal_cooling_device_unregister(). No need for clean-up flow in > case they > > + * have been registered by > devm_thermal_of_cooling_device_register() > > + */ > > + if (!dev->of_node) { > > + for (i = 0; i < EMC2305_PWM_MAX; i++) > > + if (data->cdev_data[i].cdev) > > + thermal_cooling_device_unregister(data- > >cdev_data[i].cdev); > > + } > > +} > > + > > +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((struct emc2305_data > > +*)data); > > Unnecessary typecast. It's required as otherwise there is compilation warning. > > > + > > + /* Don't show channels which are not physically connected. */ > > + if ((channel + 1) > max_channel) > > Unnecessary () > Removed > > + 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); > > + > > + switch (type) { > > + case hwmon_pwm: > > + switch (attr) { > > + case hwmon_pwm_input: > > + /* If thermal is configured - handle PWM limit setting. > */ > > + if (IS_REACHABLE(CONFIG_THERMAL)) { > > + data->cdev_data[channel].last_hwmon_state > = > > + EMC2305_PWM_DUTY2STATE(val, > data->max_state, data->pwm_max); > > + /* Update PWM only in case requested state > is not less than the > > + * last thermal state. > > + */ > > + if (data- > >cdev_data[channel].last_hwmon_state >= > > + data- > >cdev_data[channel].last_thermal_state) > > + return emc2305_set_cur_state(data- > >cdev_data[channel].cdev, > > + data- > >cdev_data[channel].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 *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 -EINVAL; > > + } > > + > > + return 0; > > +} > > + > > +static int emc2305_probe(struct i2c_client *client, const struct > > +i2c_device_id *id) { > > + struct i2c_adapter *adapter = client->adapter; > > + struct device *dev = &client->dev; > > + struct emc2305_data *data; > > + int vendor, device; > > + int ret; > > + int i; > > + > > + 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; > > + > > + device = i2c_smbus_read_byte_data(client, EMC2305_REG_DEVICE); > > + if (device != EMC2305_DEVICE) > > + 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; > > + > > + data->max_state = EMC2305_FAN_MAX_STATE; > > + data->pwm_max = EMC2305_FAN_MAX; > > + data->pwm_min = EMC2305_FAN_MIN; > > + data->pwm_channel = EMC2305_PWM_CHNL_CMN; > > + if (dev->of_node) { > > + ret = emc2305_get_tz_of(dev); > > + if (ret < 0) > > + return ret; > > + } > > + > > + 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)) { > > + ret = emc2305_set_tz(dev); > > + if (ret != 0) > > + return ret; > > + } > > + > > + for (i = 0; i < data->pwm_num; i++) > > + i2c_smbus_write_byte_data(client, > EMC2305_REG_FAN_MIN_DRIVE(i), > > +data->pwm_min); > > + > > + return 0; > > +} > > + > > +static int emc2305_remove(struct i2c_client *client) { > > + struct device *dev = &client->dev; > > + > > + if (IS_REACHABLE(CONFIG_THERMAL)) > > + emc2305_unset_tz(dev); > > It would be desirable to handle this with devm_add_action_or_reset() from > emc2305_set_tz(). > It's not required in case of devm_thermal_of_cooling_device_register Added comment. > > + return 0; > > +} > > + > > +static struct i2c_driver emc2305_driver = { > > + .class = I2C_CLASS_HWMON, > > + .driver = { > > + .name = "emc2305", > > + .of_match_table = emc2305_dt_ids, > > + }, > > + .probe = emc2305_probe, > > + .remove = emc2305_remove, > > + .id_table = emc2305_ids, > > + .address_list = emc2305_normal_i2c, > > +}; > > + > > +module_i2c_driver(emc2305_driver); > > + > > +MODULE_AUTHOR("Nvidia"); > > +MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver"); > > +MODULE_LICENSE("GPL"); > > -- > > 2.14.1 > > Thank you, Michael.
On Tue, May 24, 2022 at 04:17:01PM +0000, Michael Shych wrote: > > > > +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((struct emc2305_data > > > +*)data); > > > > Unnecessary typecast. > It's required as otherwise there is compilation warning. > Arguable. The critical part is the change from a const pointer to a non-const pointer, which is in general not a good idea. It doesn't matter here, but it would be better to declare the parameter of emc2305_get_max_channel to be a const *. Guenter
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 85c22bba439b..3c25ba0e6ef7 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -1750,6 +1750,19 @@ config SENSORS_EMC2103 This driver can also be built as a module. If so, the module will be called emc2103. +config SENSORS_EMC2305 + tristate "Microchip EMC2305 and compatible EMC2301/2/3" + depends on I2C + imply THERMAL + help + If you say yes here you get support for the Microchip EMC2305 + fan controller chips. + The Microchip EMC2305 is a fan controller for up to 5 fans. + Fan rotation speeds are reported in RPM. + + This driver can also be built as a module. If so, the module + will be called emc2305. + config SENSORS_EMC6W201 tristate "SMSC EMC6W201" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 93f2b774cc5e..e2238c207ef4 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -70,6 +70,7 @@ obj-$(CONFIG_SENSORS_DS620) += ds620.o obj-$(CONFIG_SENSORS_DS1621) += ds1621.o obj-$(CONFIG_SENSORS_EMC1403) += emc1403.o obj-$(CONFIG_SENSORS_EMC2103) += emc2103.o +obj-$(CONFIG_SENSORS_EMC2305) += emc2305.o obj-$(CONFIG_SENSORS_EMC6W201) += emc6w201.o obj-$(CONFIG_SENSORS_F71805F) += f71805f.o obj-$(CONFIG_SENSORS_F71882FG) += f71882fg.o diff --git a/drivers/hwmon/emc2305.c b/drivers/hwmon/emc2305.c new file mode 100644 index 000000000000..5c896fdfc525 --- /dev/null +++ b/drivers/hwmon/emc2305.c @@ -0,0 +1,629 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Hardware monitoring driver for EMC2305 fan controller + * + * Copyright (C) 2022 Nvidia Technologies Ltd and Delta Networks, Inc. + */ + +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/thermal.h> +#include <linux/version.h> + +static const unsigned short +emc2305_normal_i2c[] = { 0x27, 0x2c, 0x2d, 0x2e, 0x2f, 0x4c, 0x4d, I2C_CLIENT_END }; + +#define EMC2305_REG_DRIVE_FAIL_STATUS 0x27 +#define EMC2305_REG_DEVICE 0xfd +#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_PWM_MAX 5 +#define EMC2305_PWM_CHNL_CMN 0 + +#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)) + +enum emc230x_product_id { + EMC2305 = 0x34, + EMC2303 = 0x35, + EMC2302 = 0x36, + EMC2301 = 0x37, +}; + +static const struct i2c_device_id emc2305_ids[] = { + { "emc2305", 0 }, + { "emc2303", 0 }, + { "emc2302", 0 }, + { "emc2301", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, emc2305_ids); + +static const struct of_device_id emc2305_dt_ids[] = { + { .compatible = "smsc,emc2305" }, + { } +}; +MODULE_DEVICE_TABLE(of, emc2305_dt_ids); + +/** + * @cdev: cooling device; + * @curr_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; +}; + +/** + * @client: i2c client; + * @hwmon_dev: hwmon device; + * @max_state: maximum cooling state of the cooling device; + * @pwm_max: maximum PWM; + * @pwm_min: minimum PWM; + * @pwm_channel: maximum number of PWM channels; + * @cdev_data: array of cooling devices data; + */ +struct emc2305_data { + struct i2c_client *client; + struct device *hwmon_dev; + u8 max_state; + u8 pwm_max; + u8 pwm_min; + u8 pwm_num; + u8 pwm_channel; + 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(struct emc2305_data *data) +{ + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) + return data->pwm_num; + else + return data->pwm_channel; +} + +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; + + /* Retuns 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 set as EMC2305_PWM_CHNL_CMN, 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_channel == EMC2305_PWM_CHNL_CMN) + 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 thermal_cooling_device *cdev, unsigned long state) +{ + int cdev_idx; + struct emc2305_data *data = cdev->devdata; + struct i2c_client *client = data->client; + u8 val, i; + + 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; + state = max_t(unsigned long, state, data->cdev_data[cdev_idx].last_hwmon_state); + + val = EMC2305_PWM_STATE2DUTY(state, data->max_state, data->pwm_max); + if (val > EMC2305_FAN_MAX) + return -EINVAL; + + data->cdev_data[cdev_idx].cur_state = state; + if (data->pwm_channel == EMC2305_PWM_CHNL_CMN) + /* Set the same PWM value in all channels + * if common PWM channel is used. + */ + for (i = 0; i < data->pwm_num; i++) + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(i), val); + else + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(cdev_idx), val); + + 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); + 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; + return EMC2305_RPM_FACTOR * EMC2305_TACH_CNT_MULTIPLIER / (ret > 0 ? ret : 1); +} + +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; + + if (val < data->pwm_min || val > data->pwm_max) + return -EINVAL; + + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_DRIVE(channel), val); + data->cdev_data[channel].cur_state = EMC2305_PWM_DUTY2STATE(val, data->max_state, + data->pwm_max); + return 0; +} + +static int emc2305_get_tz_of(struct device *dev) +{ + struct device_node *np = dev->of_node; + struct emc2305_data *data = dev_get_drvdata(dev); + int ret = 0; + + /* OF parameters are optional - overwrite default setting + * if some of them are provided. + */ + + if (of_find_property(np, "emc2305,cooling-levels", NULL)) { + ret = of_property_read_u8(np, "emc2305,cooling-levels", &data->max_state); + if (ret) + return ret; + } + + if (of_find_property(np, "emc2305,pwm-max", NULL)) { + ret = of_property_read_u8(np, "emc2305,pwm-max", &data->pwm_max); + if (ret) + return ret; + } + + if (of_find_property(np, "emc2305,pwm-min", NULL)) { + ret = of_property_read_u8(np, "emc2305,pwm-min", &data->pwm_min); + if (ret) + return ret; + } + + /* Not defined or 0 means one thermal zone over all colling devices. + * Otherwise - separted thermal zones for each PWM channel. + */ + if (of_find_property(np, "emc2305,pwm-channel", NULL)) { + ret = of_property_read_u8(np, "emc2305,pwm-channel", &data->pwm_channel); + if (ret) + return ret; + } + + return ret; +} + +static int emc2305_set_single_tz(struct device *dev, int idx) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + long pwm = data->pwm_max; + int cdev_idx; + + cdev_idx = (idx) ? idx - 1 : 0; + + if (dev->of_node) + data->cdev_data[cdev_idx].cdev = + devm_thermal_of_cooling_device_register(dev, dev->of_node, + emc2305_fan_name[idx], data, + &emc2305_cooling_ops); + else + data->cdev_data[cdev_idx].cdev = + thermal_cooling_device_register(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); + } + emc2305_set_pwm(dev, pwm, cdev_idx); + data->cdev_data[cdev_idx].cur_state = data->max_state; + /* Set minimal PWM speed. */ + data->cdev_data[cdev_idx].last_hwmon_state = EMC2305_PWM_DUTY2STATE(data->pwm_min, + data->max_state, + data->pwm_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_channel == EMC2305_PWM_CHNL_CMN) + return emc2305_set_single_tz(dev, 0); + + for (i = 0; i < data->pwm_channel; i++) { + ret = emc2305_set_single_tz(dev, i + 1); + if (ret) + goto thermal_cooling_device_register_fail; + } + return 0; + +thermal_cooling_device_register_fail: + emc2305_unset_tz(dev); + return ret; +} + +static void emc2305_unset_tz(struct device *dev) +{ + struct emc2305_data *data = dev_get_drvdata(dev); + int i; + + /* Unregister cooling device in case they have been registered by + * thermal_cooling_device_unregister(). No need for clean-up flow in case they + * have been registered by devm_thermal_of_cooling_device_register() + */ + if (!dev->of_node) { + for (i = 0; i < EMC2305_PWM_MAX; i++) + if (data->cdev_data[i].cdev) + thermal_cooling_device_unregister(data->cdev_data[i].cdev); + } +} + +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((struct emc2305_data *)data); + + /* Don't show channels which are not physically connected. */ + if ((channel + 1) > 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); + + switch (type) { + case hwmon_pwm: + switch (attr) { + case hwmon_pwm_input: + /* If thermal is configured - handle PWM limit setting. */ + if (IS_REACHABLE(CONFIG_THERMAL)) { + data->cdev_data[channel].last_hwmon_state = + EMC2305_PWM_DUTY2STATE(val, data->max_state, data->pwm_max); + /* Update PWM only in case requested state is not less than the + * last thermal state. + */ + if (data->cdev_data[channel].last_hwmon_state >= + data->cdev_data[channel].last_thermal_state) + return emc2305_set_cur_state(data->cdev_data[channel].cdev, + data->cdev_data[channel].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 *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 -EINVAL; + } + + return 0; +} + +static int emc2305_probe(struct i2c_client *client, const struct i2c_device_id *id) +{ + struct i2c_adapter *adapter = client->adapter; + struct device *dev = &client->dev; + struct emc2305_data *data; + int vendor, device; + int ret; + int i; + + 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; + + device = i2c_smbus_read_byte_data(client, EMC2305_REG_DEVICE); + if (device != EMC2305_DEVICE) + 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; + + data->max_state = EMC2305_FAN_MAX_STATE; + data->pwm_max = EMC2305_FAN_MAX; + data->pwm_min = EMC2305_FAN_MIN; + data->pwm_channel = EMC2305_PWM_CHNL_CMN; + if (dev->of_node) { + ret = emc2305_get_tz_of(dev); + if (ret < 0) + return ret; + } + + 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)) { + ret = emc2305_set_tz(dev); + if (ret != 0) + return ret; + } + + for (i = 0; i < data->pwm_num; i++) + i2c_smbus_write_byte_data(client, EMC2305_REG_FAN_MIN_DRIVE(i), data->pwm_min); + + return 0; +} + +static int emc2305_remove(struct i2c_client *client) +{ + struct device *dev = &client->dev; + + if (IS_REACHABLE(CONFIG_THERMAL)) + emc2305_unset_tz(dev); + return 0; +} + +static struct i2c_driver emc2305_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "emc2305", + .of_match_table = emc2305_dt_ids, + }, + .probe = emc2305_probe, + .remove = emc2305_remove, + .id_table = emc2305_ids, + .address_list = emc2305_normal_i2c, +}; + +module_i2c_driver(emc2305_driver); + +MODULE_AUTHOR("Nvidia"); +MODULE_DESCRIPTION("Microchip EMC2305 fan controller driver"); +MODULE_LICENSE("GPL");