Allow gpio-fan to be used as thermal cooling device for platforms that
use GPIO maps to control fans.
Signed-off-by: Nishanth Menon <nm@xxxxxx>
---
Based on v3.19-rc3
.../devicetree/bindings/gpio/gpio-fan.txt | 14 +++
drivers/hwmon/gpio-fan.c | 93 ++++++++++++++++++--
2 files changed, 100 insertions(+), 7 deletions(-)
diff --git a/Documentation/devicetree/bindings/gpio/gpio-fan.txt b/Documentation/devicetree/bindings/gpio/gpio-fan.txt
index 2dd457a3469a..046f2f400dbb 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-fan.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-fan.txt
@@ -11,6 +11,9 @@ Required properties:
Optional properties:
- alarm-gpios: This pin going active indicates something is wrong with
the fan, and a udev event will be fired.
+- cooling-cells: If used as a cooling device, must be <2>
+ Also see: Documentation/devicetree/bindings/thermal/thermal.txt
+ min and max states are derived from the speed-map of the fan.
Examples:
@@ -23,3 +26,14 @@ Examples:
6000 2>;
alarm-gpios = <&gpio1 15 1>;
};
+
+ gpio_fan_cool: gpio_fan {
+ compatible = "gpio-fan";
+ gpios = <&gpio2 14 1
+ &gpio2 13 1>;
+ gpio-fan,speed-map = <0 0
+ 3000 1
+ 6000 2>;
+ alarm-gpios = <&gpio1 15 1>;
+ #cooling-cells = <2>; /* min followed by max */
+ };
diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 36abf814b8c7..089914c4f574 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -34,10 +34,14 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
+#include <linux/thermal.h>
+
struct gpio_fan_data {
struct platform_device *pdev;
struct device *hwmon_dev;
+ /* Cooling device if any */
+ struct thermal_cooling_device *cdev;
struct mutex lock; /* lock GPIOs operations. */
int num_ctrl;
unsigned *ctrl;
@@ -387,12 +391,63 @@ static int fan_ctrl_init(struct gpio_fan_data *fan_data,
return 0;
}
+static int gpio_fan_get_max_state(struct thermal_cooling_device *cdev,
+ unsigned long *state)
+{
+ struct gpio_fan_data *fan_data = cdev->devdata;
+
+ if (!fan_data)
+ return -EINVAL;
+
+ *state = fan_data->num_speed - 1;
+ return 0;
+}
+
+static int gpio_fan_get_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long *state)
+{
+ struct gpio_fan_data *fan_data = cdev->devdata;
+ int r;
+
+ if (!fan_data)
+ return -EINVAL;
+
+ r = get_fan_speed_index(fan_data);
+ if (r < 0)
+ return r;
+
+ *state = r;
+ return 0;
+
+}
+
+static int gpio_fan_set_cur_state(struct thermal_cooling_device *cdev,
+ unsigned long state)
+{
+ struct gpio_fan_data *fan_data = cdev->devdata;
+
+ if (!fan_data)
+ return -EINVAL;
+
+ set_fan_speed(fan_data, state);
+
+ return 0;
+}
+
+static const struct thermal_cooling_device_ops gpio_fan_cooling_ops = {
+ .get_max_state = gpio_fan_get_max_state,
+ .get_cur_state = gpio_fan_get_cur_state,
+ .set_cur_state = gpio_fan_set_cur_state,
+
+};
+
#ifdef CONFIG_OF_GPIO
/*
* Translate OpenFirmware node properties into platform_data
*/
static int gpio_fan_get_of_pdata(struct device *dev,
- struct gpio_fan_platform_data *pdata)
+ struct gpio_fan_platform_data *pdata,
+ struct gpio_fan_data *fan_data)
{
struct device_node *node;
struct gpio_fan_speed *speed;
@@ -480,6 +535,12 @@ static int gpio_fan_get_of_pdata(struct device *dev,
pdata->alarm = alarm;
}
+ fan_data->cdev = thermal_of_cooling_device_register(node, "gpio-fan",
+ fan_data,
+ &gpio_fan_cooling_ops);
+ if (IS_ERR(fan_data->cdev))
+ dev_dbg(dev, "gpio-fan has no valid cooling DT property\n");
+
return 0;
}
@@ -495,6 +556,11 @@ static int gpio_fan_probe(struct platform_device *pdev)
struct gpio_fan_data *fan_data;
struct gpio_fan_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
+ GFP_KERNEL);
+ if (!fan_data)
+ return -ENOMEM;
+
#ifdef CONFIG_OF_GPIO
if (!pdata) {
pdata = devm_kzalloc(&pdev->dev,
@@ -503,20 +569,19 @@ static int gpio_fan_probe(struct platform_device *pdev)
if (!pdata)
return -ENOMEM;
- err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
+ err = gpio_fan_get_of_pdata(&pdev->dev, pdata, fan_data);
if (err)
return err;
}
#else /* CONFIG_OF_GPIO */
if (!pdata)
return -EINVAL;
+ /* Optional cooling device register for non Device tree platforms */
+ fan_data->cdev = thermal_cooling_device_register("gpio-fan",
+ fan_data,
+ &gpio_fan_cooling_ops);
#endif /* CONFIG_OF_GPIO */
- fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
- GFP_KERNEL);
- if (!fan_data)
- return -ENOMEM;
-
fan_data->pdev = pdev;
platform_set_drvdata(pdev, fan_data);
mutex_init(&fan_data->lock);
@@ -550,10 +615,23 @@ static int gpio_fan_probe(struct platform_device *pdev)
return 0;
}
+static int gpio_fan_remove(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);
+
+ return 0;
+}
+
static void gpio_fan_shutdown(struct platform_device *pdev)
{
struct gpio_fan_data *fan_data = dev_get_drvdata(&pdev->dev);
+ if (!IS_ERR(fan_data->cdev))
+ thermal_cooling_device_unregister(fan_data->cdev);
+
if (fan_data->ctrl)
set_fan_speed(fan_data, 0);
}
@@ -589,6 +667,7 @@ 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",
--
1.7.9.5
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