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emc2305 / i2c-fan updates for mainline driver #7505

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eb729a0
Revert "hwmon: emc2305: fixups for driver submitted to mailing lists"
6by9 Jul 15, 2026
3f07aed
hwmon: emc2305: Acknowledge all errors during probe
6by9 Jul 15, 2026
d765cc8
dtoverlays: Update i2c-fan for the mainline emc2305 driver
6by9 Jul 16, 2026
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4 changes: 0 additions & 4 deletions arch/arm/boot/dts/overlays/README
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Original file line number Diff line number Diff line change
Expand Up @@ -2247,10 +2247,6 @@ Params: addr Sets the address for the fan controller. Note
i2c-bus Supports all the standard I2C bus selection
parameters - see "dtoverlay -h i2c-bus"

minpwm PWM setting for the fan when the SoC is below
mintemp (range 0-255. default 0)
maxpwm PWM setting for the fan when the SoC is above
maxtemp (range 0-255. default 255)
midtemp Temperature (in millicelsius) at which the fan
begins to speed up (default 50000)

Expand Down
19 changes: 12 additions & 7 deletions arch/arm/boot/dts/overlays/i2c-fan-overlay.dts
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,14 @@
emc2301: emc2301@2f {
compatible = "microchip,emc2301", "microchip,emc2305";
reg = <0x2f>;
#cooling-cells = <0x02>;
#pwm-cells = <3>;

fan0: fan@0 {
reg = <0x0>;
pwms = <&emc2301 26000 0 1>;
#cooling-cells = <2>;
};

};
};
};
Expand Down Expand Up @@ -52,26 +59,24 @@
__overlay__ {
map0: map0 {
trip = <&fanmid0>;
cooling-device = <&emc2301 2 6>;
cooling-device = <&fan0 2 6>;
};
map1: map1 {
trip = <&fanmax0>;
cooling-device = <&emc2301 7 THERMAL_NO_LIMIT>;
cooling-device = <&fan0 7 THERMAL_NO_LIMIT>;
};
};
};

__overrides__ {
addr = <&emc2301>,"reg:0";
minpwm = <&emc2301>,"emc2305,pwm-min.0";
maxpwm = <&emc2301>,"emc2305,pwm-max.0";
midtemp = <&fanmid0>,"temperature:0";
midtemp_hyst = <&fanmid0>,"hysteresis:0";
maxtemp = <&fanmax0>,"temperature:0";
maxtemp_hyst = <&fanmax0>,"hysteresis:0";

emc2301 = <0>,"+0",
<&map0>,"cooling-device:0=",<&emc2301>,
<&map1>,"cooling-device:0=",<&emc2301>;
<&map0>,"cooling-device:0=",<&fan0>,
<&map1>,"cooling-device:0=",<&fan0>;
};
};
104 changes: 6 additions & 98 deletions drivers/hwmon/emc2305.c
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Original file line number Diff line number Diff line change
Expand Up @@ -122,7 +122,6 @@ struct emc2305_data {
bool pwm_separate;
s16 pwm_shutdown[EMC2305_PWM_MAX];
u8 pwm_min[EMC2305_PWM_MAX];
u8 pwm_max;
u16 pwm_freq[EMC2305_PWM_MAX];
struct emc2305_cdev_data cdev_data[EMC2305_PWM_MAX];
};
Expand Down Expand Up @@ -294,7 +293,7 @@ static int emc2305_set_pwm(struct device *dev, long val, int channel)
struct i2c_client *client = data->client;
int ret;

if (val < data->pwm_min[channel] || val > data->pwm_max)
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);
Expand All @@ -305,49 +304,6 @@ static int emc2305_set_pwm(struct device *dev, long val, int channel)
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;
u8 val;
int i;

/* OF parameters are optional - overwrite default setting
* if some of them are provided.
*/

ret = of_property_read_u8(np, "emc2305,cooling-levels", &val);
if (!ret)
data->max_state = val;
else if (ret != -EINVAL)
return ret;

ret = of_property_read_u8(np, "emc2305,pwm-max", &val);
if (!ret)
data->pwm_max = val;
else if (ret != -EINVAL)
return ret;

ret = of_property_read_u8(np, "emc2305,pwm-min", &val);
if (!ret)
for (i = 0; i < EMC2305_PWM_MAX; i++)
data->pwm_min[i] = val;
else if (ret != -EINVAL)
return ret;

/* Not defined or 0 means one thermal zone over all cooling devices.
* Otherwise - separated thermal zones for each PWM channel.
*/
ret = of_property_read_u8(np, "emc2305,pwm-channel", &val);
if (!ret)
data->pwm_separate = (val != 0);
else if (ret != -EINVAL)
return ret;

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);
Expand All @@ -357,16 +313,10 @@ static int emc2305_set_single_tz(struct device *dev, struct device_node *fan_nod
cdev_idx = (idx) ? idx - 1 : 0;
pwm = data->pwm_min[cdev_idx];

if (dev->of_node)
data->cdev_data[cdev_idx].cdev =
devm_thermal_of_child_cooling_device_register(dev, fan_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);
data->cdev_data[cdev_idx].cdev =
devm_thermal_of_child_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]);
Expand Down Expand Up @@ -399,19 +349,6 @@ static int emc2305_set_single_tz(struct device *dev, struct device_node *fan_nod
return 0;
}

static void emc2305_unset_tz(struct device *dev)
{
struct emc2305_data *data = dev_get_drvdata(dev);
int i;

/* Unregister cooling device. */
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 int emc2305_set_tz(struct device *dev)
{
struct emc2305_data *data = dev_get_drvdata(dev);
Expand All @@ -423,13 +360,9 @@ static int emc2305_set_tz(struct device *dev)
for (i = 0; i < data->pwm_num; i++) {
ret = emc2305_set_single_tz(dev, dev->of_node, i + 1);
if (ret)
goto thermal_cooling_device_register_fail;
return ret;
}
return 0;

thermal_cooling_device_register_fail:
emc2305_unset_tz(dev);
return ret;
}

static umode_t
Expand Down Expand Up @@ -748,7 +681,6 @@ static int emc2305_probe(struct i2c_client *client)
data->pwm_min[i] = pdata->pwm_min[i];
data->pwm_freq[i] = pdata->pwm_freq[i];
}
data->pwm_max = EMC2305_FAN_MAX;
} else {
data->max_state = EMC2305_FAN_MAX_STATE;
data->pwm_separate = false;
Expand All @@ -758,24 +690,12 @@ static int emc2305_probe(struct i2c_client *client)
data->pwm_min[i] = EMC2305_FAN_MIN;
data->pwm_freq[i] = base_freq_table[3];
}
data->pwm_max = EMC2305_FAN_MAX;
if (dev->of_node) {
ret = emc2305_get_tz_of(dev);
if (ret < 0)
return ret;
}
}
} 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->pwm_max = EMC2305_FAN_MAX;
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,
Expand Down Expand Up @@ -851,29 +771,17 @@ static void emc2305_shutdown(struct i2c_client *client)

static const struct of_device_id of_emc2305_match_table[] = {
{ .compatible = "microchip,emc2305", },
{ .compatible = "microchip,emc2303", },
{ .compatible = "microchip,emc2302", },
{ .compatible = "microchip,emc2301", },
{},
};
MODULE_DEVICE_TABLE(of, of_emc2305_match_table);

static void emc2305_remove(struct i2c_client *client)
{
struct device *dev = &client->dev;

if (IS_REACHABLE(CONFIG_THERMAL))
emc2305_unset_tz(dev);
}

static struct i2c_driver emc2305_driver = {
.driver = {
.name = "emc2305",
.of_match_table = of_emc2305_match_table,
},
.probe = emc2305_probe,
.shutdown = emc2305_shutdown,
.remove = emc2305_remove,
.id_table = emc2305_ids,
};

Expand Down
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