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Message-ID: <20250324124550.989292-1-alexander.stein@ew.tq-group.com>
Date: Mon, 24 Mar 2025 13:45:49 +0100
From: Alexander Stein <alexander.stein@...tq-group.com>
To: Jean Delvare <jdelvare@...e.com>,
Guenter Roeck <linux@...ck-us.net>
Cc: Alexander Stein <alexander.stein@...tq-group.com>,
linux-hwmon@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH v3 1/1] hwmon: (gpio-fan) Add regulator support
FANs might be supplied by a regulator which needs to be enabled as well.
This is implemented using runtime PM. Every time speed_index changes from
0 to non-zero and vise versa RPM is resumed or suspended.
Intitial RPM state is determined by initial value of speed_index.
Signed-off-by: Alexander Stein <alexander.stein@...tq-group.com>
---
Patch 1 & 2 from v1 [1] have already been applied, although number 2 [2] is not
yet showing in next-20250305. Patches 3 & 4 (just removing comments) from v1
have been dropped, so only this patch remains.
Changes in v3:
* Remove noisy dev_err calls related to runtime pm
* Properly propagate return codes from set_fan_speed
Changes in v2:
* Make regulator non-optional
[1] https://lore.kernel.org/all/20250210145934.761280-1-alexander.stein@ew.tq-group.com/
[2] https://web.git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git/commit/?h=hwmon-next&id=9fee7d19bab635f89223cc40dfd2c8797fdc4988
---
drivers/hwmon/gpio-fan.c | 104 +++++++++++++++++++++++++++++++++------
1 file changed, 90 insertions(+), 14 deletions(-)
diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index cee3fa146d69a..4c736b7eb5473 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -20,6 +20,9 @@
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/of_platform.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/regulator/consumer.h>
#include <linux/thermal.h>
struct gpio_fan_speed {
@@ -42,6 +45,7 @@ struct gpio_fan_data {
bool pwm_enable;
struct gpio_desc *alarm_gpio;
struct work_struct alarm_work;
+ struct regulator *supply;
};
/*
@@ -125,13 +129,32 @@ static int __get_fan_ctrl(struct gpio_fan_data *fan_data)
}
/* Must be called with fan_data->lock held, except during initialization. */
-static void set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
+static int set_fan_speed(struct gpio_fan_data *fan_data, int speed_index)
{
if (fan_data->speed_index == speed_index)
- return;
+ return 0;
+
+ if (fan_data->speed_index == 0 && speed_index > 0) {
+ int ret;
+
+ ret = pm_runtime_resume_and_get(fan_data->dev);
+ if (ret < 0)
+ return ret;
+ }
__set_fan_ctrl(fan_data, fan_data->speed[speed_index].ctrl_val);
+
+ if (fan_data->speed_index > 0 && speed_index == 0) {
+ int ret;
+
+ ret = pm_runtime_put_sync(fan_data->dev);
+ if (ret < 0)
+ return ret;
+ }
+
fan_data->speed_index = speed_index;
+
+ return 0;
}
static int get_fan_speed_index(struct gpio_fan_data *fan_data)
@@ -189,7 +212,9 @@ static ssize_t pwm1_store(struct device *dev, struct device_attribute *attr,
}
speed_index = DIV_ROUND_UP(pwm * (fan_data->num_speed - 1), 255);
- set_fan_speed(fan_data, speed_index);
+ ret = set_fan_speed(fan_data, speed_index);
+ if (!ret)
+ ret = count;
exit_unlock:
mutex_unlock(&fan_data->lock);
@@ -211,6 +236,7 @@ static ssize_t pwm1_enable_store(struct device *dev,
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
unsigned long val;
+ int ret;
if (kstrtoul(buf, 10, &val) || val > 1)
return -EINVAL;
@@ -224,11 +250,14 @@ static ssize_t pwm1_enable_store(struct device *dev,
/* Disable manual control mode: set fan at full speed. */
if (val == 0)
- set_fan_speed(fan_data, fan_data->num_speed - 1);
+ ret = set_fan_speed(fan_data, fan_data->num_speed - 1);
mutex_unlock(&fan_data->lock);
- return count;
+ if (ret)
+ return ret;
+ else
+ return count;
}
static ssize_t pwm1_mode_show(struct device *dev,
@@ -279,7 +308,7 @@ static ssize_t set_rpm(struct device *dev, struct device_attribute *attr,
goto exit_unlock;
}
- set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
+ ret = set_fan_speed(fan_data, rpm_to_speed_index(fan_data, rpm));
exit_unlock:
mutex_unlock(&fan_data->lock);
@@ -386,6 +415,7 @@ static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
unsigned long state)
{
struct gpio_fan_data *fan_data = cdev->devdata;
+ int ret;
if (!fan_data)
return -EINVAL;
@@ -395,11 +425,11 @@ static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
mutex_lock(&fan_data->lock);
- set_fan_speed(fan_data, state);
+ ret = set_fan_speed(fan_data, state);
mutex_unlock(&fan_data->lock);
- return 0;
+ return ret;
}
static const struct thermal_cooling_device_ops gpio_fan_cool_ops = {
@@ -499,6 +529,8 @@ static void gpio_fan_stop(void *data)
mutex_lock(&fan_data->lock);
set_fan_speed(data, 0);
mutex_unlock(&fan_data->lock);
+
+ pm_runtime_disable(fan_data->dev);
}
static int gpio_fan_probe(struct platform_device *pdev)
@@ -521,6 +553,11 @@ static int gpio_fan_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, fan_data);
mutex_init(&fan_data->lock);
+ fan_data->supply = devm_regulator_get(dev, "fan");
+ if (IS_ERR(fan_data->supply))
+ return dev_err_probe(dev, PTR_ERR(fan_data->supply),
+ "Failed to get fan-supply");
+
/* Configure control GPIOs if available. */
if (fan_data->gpios && fan_data->num_gpios > 0) {
if (!fan_data->speed || fan_data->num_speed <= 1)
@@ -548,6 +585,17 @@ static int gpio_fan_probe(struct platform_device *pdev)
return err;
}
+ pm_runtime_set_suspended(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+ /* If current GPIO state is active, mark RPM as active as well */
+ if (fan_data->speed_index > 0) {
+ int ret;
+
+ ret = pm_runtime_resume_and_get(&pdev->dev);
+ if (ret)
+ return ret;
+ }
+
/* Optional cooling device register for Device tree platforms */
fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
"gpio-fan", fan_data, &gpio_fan_cool_ops);
@@ -568,41 +616,69 @@ static void gpio_fan_shutdown(struct platform_device *pdev)
}
}
+static int gpio_fan_runtime_suspend(struct device *dev)
+{
+ struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (fan_data->supply)
+ ret = regulator_disable(fan_data->supply);
+
+ return ret;
+}
+
+static int gpio_fan_runtime_resume(struct device *dev)
+{
+ struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
+ int ret = 0;
+
+ if (fan_data->supply)
+ ret = regulator_enable(fan_data->supply);
+
+ return ret;
+}
+
static int gpio_fan_suspend(struct device *dev)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
+ int ret = 0;
if (fan_data->gpios) {
fan_data->resume_speed = fan_data->speed_index;
mutex_lock(&fan_data->lock);
- set_fan_speed(fan_data, 0);
+ ret = set_fan_speed(fan_data, 0);
mutex_unlock(&fan_data->lock);
}
- return 0;
+ return ret;
}
static int gpio_fan_resume(struct device *dev)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(dev);
+ int ret = 0;
if (fan_data->gpios) {
mutex_lock(&fan_data->lock);
- set_fan_speed(fan_data, fan_data->resume_speed);
+ ret = set_fan_speed(fan_data, fan_data->resume_speed);
mutex_unlock(&fan_data->lock);
}
- return 0;
+ return ret;
}
-static DEFINE_SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);
+static const struct dev_pm_ops gpio_fan_pm = {
+ RUNTIME_PM_OPS(gpio_fan_runtime_suspend,
+ gpio_fan_runtime_resume, NULL)
+ SYSTEM_SLEEP_PM_OPS(gpio_fan_suspend, gpio_fan_resume)
+};
static struct platform_driver gpio_fan_driver = {
.probe = gpio_fan_probe,
.shutdown = gpio_fan_shutdown,
.driver = {
.name = "gpio-fan",
- .pm = pm_sleep_ptr(&gpio_fan_pm),
+ .pm = pm_ptr(&gpio_fan_pm),
.of_match_table = of_gpio_fan_match,
},
};
--
2.43.0
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