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* [PATCH] hwmon: max6650: add thermal cooling device capability
@ 2019-04-18 16:28 Jean-Francois Dagenais
  0 siblings, 0 replies; 1+ messages in thread
From: Jean-Francois Dagenais @ 2019-04-18 16:28 UTC (permalink / raw)
  To: linux-hwmon; +Cc: jdelvare, linux, Jean-Francois Dagenais

This allows max6650 devices to be referenced in dts as a cooling device.

The pwm value seems duplicated in cooling_dev_state but since pwm goes
through rounding logic into data->dac, it is modified and messes with
the thermal zone state algorithms. It's also better to serve a cache
value, thus avoiding periodic actual i2c traffic.

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
---
 drivers/hwmon/max6650.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/max6650.c b/drivers/hwmon/max6650.c
index 61135a2d0cff..1b8efbb8adbf 100644
--- a/drivers/hwmon/max6650.c
+++ b/drivers/hwmon/max6650.c
@@ -40,6 +40,7 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
 #include <linux/of_device.h>
+#include <linux/thermal.h>
 
 /*
  * Insmod parameters
@@ -113,6 +114,7 @@ module_param(clock, int, 0444);
 struct max6650_data {
 	struct i2c_client *client;
 	const struct attribute_group *groups[3];
+	struct thermal_cooling_device *cooling_dev;
 	struct mutex update_lock;
 	int nr_fans;
 	char valid; /* zero until following fields are valid */
@@ -125,6 +127,7 @@ struct max6650_data {
 	u8 count;
 	u8 dac;
 	u8 alarm;
+	unsigned long cooling_dev_state;
 };
 
 static const u8 tach_reg[] = {
@@ -694,6 +697,63 @@ static int max6650_init_client(struct max6650_data *data,
 	return 0;
 }
 
+#if IS_ENABLED(CONFIG_THERMAL)
+/* thermal cooling device callbacks */
+static int max6650_get_max_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	*state = 255;
+	dev_notice(&cdev->device, "%s %lu\n", __func__, *state);
+	return 0;
+}
+
+static int max6650_get_cur_state(struct thermal_cooling_device *cdev,
+				 unsigned long *state)
+{
+	struct max6650_data *data = cdev->devdata;
+
+	*state = data->cooling_dev_state;
+
+	return 0;
+}
+
+static int
+max6650_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+	struct max6650_data *data = cdev->devdata;
+	struct i2c_client *client = data->client;
+	int err;
+
+	state = clamp_val(state, 0, 255);
+
+	mutex_lock(&data->update_lock);
+
+	if (data->config & MAX6650_CFG_V12)
+		data->dac = 180 - (180 * state)/255;
+	else
+		data->dac = 76 - (76 * state)/255;
+
+	err = i2c_smbus_write_byte_data(client, MAX6650_REG_DAC, data->dac);
+
+	if (!err) {
+		max6650_set_operating_mode(data, state ?
+						   MAX6650_CFG_MODE_OPEN_LOOP :
+						   MAX6650_CFG_MODE_OFF);
+		data->cooling_dev_state = state;
+	}
+
+	mutex_unlock(&data->update_lock);
+
+	return err < 0 ? err : 0;
+}
+
+static const struct thermal_cooling_device_ops max6650_cooling_ops = {
+	.get_max_state = max6650_get_max_state,
+	.get_cur_state = max6650_get_cur_state,
+	.set_cur_state = max6650_set_cur_state,
+};
+#endif
+
 static int max6650_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
@@ -709,6 +769,7 @@ static int max6650_probe(struct i2c_client *client,
 		return -ENOMEM;
 
 	data->client = client;
+	i2c_set_clientdata(client, data);
 	mutex_init(&data->update_lock);
 	data->nr_fans = of_id ? (int)(uintptr_t)of_id->data : id->driver_data;
 
@@ -727,7 +788,34 @@ static int max6650_probe(struct i2c_client *client,
 	hwmon_dev = devm_hwmon_device_register_with_groups(dev,
 							   client->name, data,
 							   data->groups);
-	return PTR_ERR_OR_ZERO(hwmon_dev);
+	err = PTR_ERR_OR_ZERO(hwmon_dev);
+	if (err)
+		return err;
+
+#if IS_ENABLED(CONFIG_THERMAL)
+	data->cooling_dev =
+		thermal_of_cooling_device_register(client->dev.of_node,
+						   id->name, data,
+						   &max6650_cooling_ops);
+	if (IS_ERR(data->cooling_dev)) {
+		err = PTR_ERR(data->cooling_dev);
+		dev_err(&client->dev,
+			"Failed to register as cooling device (%d)\n", err);
+		return err;
+	}
+
+	thermal_cdev_update(data->cooling_dev);
+#endif
+	return 0;
+}
+
+static int max6650_remove(struct i2c_client *client)
+{
+	struct max6650_data *data = i2c_get_clientdata(client);
+
+	thermal_cooling_device_unregister(data->cooling_dev);
+
+	return 0;
 }
 
 static const struct i2c_device_id max6650_id[] = {
@@ -743,6 +831,7 @@ static struct i2c_driver max6650_driver = {
 		.of_match_table = of_match_ptr(max6650_dt_match),
 	},
 	.probe		= max6650_probe,
+	.remove		= max6650_remove,
 	.id_table	= max6650_id,
 };
 
-- 
2.11.0


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2019-04-18 16:28 [PATCH] hwmon: max6650: add thermal cooling device capability Jean-Francois Dagenais

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