Commit 99cb5e9f authored by Christian Lamparter's avatar Christian Lamparter Committed by Guenter Roeck
Browse files

hwmon: (tc654) Add thermal_cooling device support 



Adds thermal_cooling device support to the tc654/tc655
driver. This make it possible to integrate it into a
device-tree supported thermal-zone node as a
cooling device.

I have been using this patch as part of the Netgear WNDR4700
Centria NAS Router support within OpenWrt since 2016.

Signed-off-by: default avatarChristian Lamparter <chunkeey@gmail.com>
Link: https://lore.kernel.org/r/20220213004733.2421193-1-chunkeey@gmail.com


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 5f86cce6

drivers/hwmon/tc654.c

+89 −15
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/module.h>

#include <linux/mutex.h>

#include <linux/slab.h>

#include <linux/thermal.h>

#include <linux/util_macros.h>



enum tc654_regs {
@@ -379,28 +380,20 @@ static ssize_t pwm_show(struct device *dev, struct device_attribute *da, 
	return sprintf(buf, "%d\n", pwm);

}



static ssize_t pwm_store(struct device *dev, struct device_attribute *da,

			 const char *buf, size_t count)

static int _set_pwm(struct tc654_data *data, unsigned long val)

{

	struct tc654_data *data = dev_get_drvdata(dev);

	struct i2c_client *client = data->client;

	unsigned long val;

	int ret;



	if (kstrtoul(buf, 10, &val))

		return -EINVAL;

	if (val > 255)

		return -EINVAL;



	mutex_lock(&data->update_lock);



	if (val == 0)

	if (val == 0) {

		data->config |= TC654_REG_CONFIG_SDM;

	else

		data->duty_cycle = 0;

	} else {

		data->config &= ~TC654_REG_CONFIG_SDM;



	data->duty_cycle = find_closest(val, tc654_pwm_map,

					ARRAY_SIZE(tc654_pwm_map));

		data->duty_cycle = val - 1;

	}



	ret = i2c_smbus_write_byte_data(client, TC654_REG_CONFIG, data->config);

	if (ret < 0)
@@ -411,6 +404,24 @@ static ssize_t pwm_store(struct device *dev, struct device_attribute *da, 


out:

	mutex_unlock(&data->update_lock);

	return ret;

}



static ssize_t pwm_store(struct device *dev, struct device_attribute *da,

			 const char *buf, size_t count)

{

	struct tc654_data *data = dev_get_drvdata(dev);

	unsigned long val;

	int ret;



	if (kstrtoul(buf, 10, &val))

		return -EINVAL;

	if (val > 255)

		return -EINVAL;

	if (val > 0)

		val = find_closest(val, tc654_pwm_map, ARRAY_SIZE(tc654_pwm_map)) + 1;



	ret = _set_pwm(data, val);

	return ret < 0 ? ret : count;

}
@@ -442,6 +453,58 @@ static struct attribute *tc654_attrs[] = { 


ATTRIBUTE_GROUPS(tc654);



/*

 * thermal cooling device functions

 *

 * Account for the "ShutDown Mode (SDM)" state by offsetting

 * the 16 PWM duty cycle states by 1.

 *

 * State  0 =   0% PWM | Shutdown - Fan(s) are off

 * State  1 =  30% PWM | duty_cycle =  0

 * State  2 = ~35% PWM | duty_cycle =  1

 * [...]

 * State 15 = ~95% PWM | duty_cycle = 14

 * State 16 = 100% PWM | duty_cycle = 15

 */

#define TC654_MAX_COOLING_STATE	16



static int tc654_get_max_state(struct thermal_cooling_device *cdev, unsigned long *state)

{

	*state = TC654_MAX_COOLING_STATE;

	return 0;

}



static int tc654_get_cur_state(struct thermal_cooling_device *cdev, unsigned long *state)

{

	struct tc654_data *data = tc654_update_client(cdev->devdata);



	if (IS_ERR(data))

		return PTR_ERR(data);



	if (data->config & TC654_REG_CONFIG_SDM)

		*state = 0;	/* FAN is off */

	else

		*state = data->duty_cycle + 1;	/* offset PWM States by 1 */



	return 0;

}



static int tc654_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)

{

	struct tc654_data *data = tc654_update_client(cdev->devdata);



	if (IS_ERR(data))

		return PTR_ERR(data);



	return _set_pwm(data, clamp_val(state, 0, TC654_MAX_COOLING_STATE));

}



static const struct thermal_cooling_device_ops tc654_fan_cool_ops = {

	.get_max_state = tc654_get_max_state,

	.get_cur_state = tc654_get_cur_state,

	.set_cur_state = tc654_set_cur_state,

};



/*

 * device probe and removal

 */
@@ -472,7 +535,18 @@ static int tc654_probe(struct i2c_client *client) 
	hwmon_dev =

	    devm_hwmon_device_register_with_groups(dev, client->name, data,

						   tc654_groups);

	return PTR_ERR_OR_ZERO(hwmon_dev);

	if (IS_ERR(hwmon_dev))

		return PTR_ERR(hwmon_dev);



	if (IS_ENABLED(CONFIG_THERMAL)) {

		struct thermal_cooling_device *cdev;



		cdev = devm_thermal_of_cooling_device_register(dev, dev->of_node, client->name,

							       hwmon_dev, &tc654_fan_cool_ops);

		return PTR_ERR_OR_ZERO(cdev);

	}



	return 0;

}



static const struct i2c_device_id tc654_id[] = {