> -----Original Message-----
> From: Guenter Roeck <groeck7@xxxxxxxxx> On Behalf Of Guenter Roeck
> Sent: Saturday, April 30, 2022 3:57 PM
> To: Michael Shych <michaelsh@xxxxxxxxxx>
> Cc: robh+dt@xxxxxxxxxx; linux-hwmon@xxxxxxxxxxxxxxx;
> devicetree@xxxxxxxxxxxxxxx; Vadim Pasternak <vadimp@xxxxxxxxxx>
> 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@xxxxxxxxxx wrote:
> > From: Michael Shych <michaelsh@xxxxxxxxxx>
> >
> > 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@xxxxxxxxxx>
> > Reviewed-by: Vadim Pasternak <vadimp@xxxxxxxxxx>
> > ---
> > 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.
