summaryrefslogtreecommitdiff
path: root/drivers/hwmon
diff options
context:
space:
mode:
authorChristian Lamparter <chunkeey@gmail.com>2022-02-13 01:47:33 +0100
committerGuenter Roeck <linux@roeck-us.net>2022-02-27 17:03:18 -0800
commit99cb5e9f7a78857657220f65533dce550331d629 (patch)
treec2687e36867da71e098e5cabcf0e4dba7660017e /drivers/hwmon
parent5f86cce61c1d12219b2ea25b9404bf263a77dd72 (diff)
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: Christian Lamparter <chunkeey@gmail.com> Link: https://lore.kernel.org/r/20220213004733.2421193-1-chunkeey@gmail.com Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/tc654.c104
1 files changed, 89 insertions, 15 deletions
diff --git a/drivers/hwmon/tc654.c b/drivers/hwmon/tc654.c
index a52ca72af120..54cd33d09688 100644
--- a/drivers/hwmon/tc654.c
+++ b/drivers/hwmon/tc654.c
@@ -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;
}
@@ -443,6 +454,58 @@ 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[] = {