[PATCH 3/6] hwmon: (gpio-fan) Use devm_thermal_of_cooling_device_register

Guenter Roeck
2019-04-18T19:58:17Z

Call devm_thermal_of_cooling_device_register() to register the cooling
device. Also use devm_add_action_or_reset() to stop the fan on device
removal. This fixes a race condition since the fan was stopped before
the hwmon device was removed.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
drivers/hwmon/gpio-fan.c | 25 +++++++++----------------
1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index f1bf67aca9e8..3f6e5b4e3997 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -498,6 +498,11 @@ static const struct of_device_id of_gpio_fan_match[] = {
};
MODULE_DEVICE_TABLE(of, of_gpio_fan_match);

+static void gpio_fan_stop(void *data)
+{
+ set_fan_speed(data, 0);
+}
+
static int gpio_fan_probe(struct platform_device *pdev)
{
int err;
@@ -532,6 +537,7 @@ static int gpio_fan_probe(struct platform_device *pdev)
err = fan_ctrl_init(fan_data);
if (err)
return err;
+ devm_add_action_or_reset(dev, gpio_fan_stop, fan_data);
}

/* Make this driver part of hwmon class. */
@@ -543,32 +549,20 @@ static int gpio_fan_probe(struct platform_device *pdev)
return PTR_ERR(fan_data->hwmon_dev);

/* Optional cooling device register for Device tree platforms */
- fan_data->cdev = thermal_of_cooling_device_register(np,
- "gpio-fan",
- fan_data,
- &gpio_fan_cool_ops);
+ fan_data->cdev = devm_thermal_of_cooling_device_register(dev, np,
+ "gpio-fan", fan_data, &gpio_fan_cool_ops);

dev_info(dev, "GPIO fan initialized\n");

return 0;
}

-static int gpio_fan_remove(struct platform_device *pdev)
+static void gpio_fan_shutdown(struct platform_device *pdev)
{
struct gpio_fan_data *fan_data = platform_get_drvdata(pdev);

- if (!IS_ERR(fan_data->cdev))
- thermal_cooling_device_unregister(fan_data->cdev);
-
if (fan_data->gpios)
set_fan_speed(fan_data, 0);
-
- return 0;
-}
-
-static void gpio_fan_shutdown(struct platform_device *pdev)
-{
- gpio_fan_remove(pdev);
}

#ifdef CONFIG_PM_SLEEP
@@ -602,7 +596,6 @@ static SIMPLE_DEV_PM_OPS(gpio_fan_pm, gpio_fan_suspend, gpio_fan_resume);

static struct platform_driver gpio_fan_driver = {
.probe = gpio_fan_probe,
- .remove = gpio_fan_remove,
.shutdown = gpio_fan_shutdown,
.driver = {
.name = "gpio-fan",
--
2.7.4