Allow a gpio-fan to be defined in devicetree, see binding documentation
for details.
Signed-off-by: Jamie Lentin <j...@lentin.co.uk>
Acked-by: Andrew Lunn <and...@lunn.ch>
---
Changes since V2:-
* Correct error message terminology
* Check of_gpio_count returns some GPIOs [Guenter Roeck]
* Whitespace fix [Guenter Roeck]
Changes since V1:-
* Don't hide return codes [Guenter Roeck]
* Remove typecast noise [Guenter Roeck]
* Use of_find_property instead of counting u32s [Guenter Roeck]
* Don't count GPIOs twice [Andrew Lunn]
* Use of_prop_next_u32 to get records in a more obvious fashion
* Use CONFIG_OF_GPIO instead of CONFIG_OF
* Apply __devinitdata to of_gpio_fan_match [Andrew Lunn]
---
.../devicetree/bindings/gpio/gpio-fan.txt | 25 ++++
drivers/hwmon/gpio-fan.c | 120 ++++++++++++++++++++
2 files changed, 145 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/gpio-fan.txt
diff --git a/Documentation/devicetree/bindings/gpio/gpio-fan.txt
b/Documentation/devicetree/bindings/gpio/gpio-fan.txt
new file mode 100644
index 0000000..2dd457a
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/gpio-fan.txt
@@ -0,0 +1,25 @@
+Bindings for fan connected to GPIO lines
+
+Required properties:
+- compatible : "gpio-fan"
+- gpios: Specifies the pins that map to bits in the control value,
+ ordered MSB-->LSB.
+- gpio-fan,speed-map: A mapping of possible fan RPM speeds and the
+ control value that should be set to achieve them. This array
+ must have the RPM values in ascending order.
+
+Optional properties:
+- alarm-gpios: This pin going active indicates something is wrong with
+ the fan, and a udev event will be fired.
+
+Examples:
+
+ gpio_fan {
+ compatible = "gpio-fan";
+ gpios = <&gpio1 14 1
+ &gpio1 13 1>;
+ gpio-fan,speed-map = <0 0
+ 3000 1
+ 6000 2>;
+ alarm-gpios = <&gpio1 15 1>;
+ };
diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 2f4b01b..36509ae 100644
--- a/drivers/hwmon/gpio-fan.c
+++ b/drivers/hwmon/gpio-fan.c
@@ -31,6 +31,8 @@
#include <linux/hwmon.h>
#include <linux/gpio.h>
#include <linux/gpio-fan.h>
+#include <linux/of_platform.h>
+#include <linux/of_gpio.h>
struct gpio_fan_data {
struct platform_device *pdev;
@@ -400,14 +402,131 @@ static ssize_t show_name(struct device *dev,
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
+
+#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 device_node *node;
+ struct gpio_fan_speed *speed;
+ unsigned *ctrl;
+ unsigned i;
+ u32 u;
+ struct property *prop;
+ const __be32 *p;
+
+ node = dev->of_node;
+
+ /* Fill GPIO pin array */
+ pdata->num_ctrl = of_gpio_count(node);
+ if (!pdata->num_ctrl) {
+ dev_err(dev, "gpios DT property empty / missing");
+ return -ENODEV;
+ }
+ ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
+ GFP_KERNEL);
+ if (!ctrl)
+ return -ENOMEM;
+ for (i = 0; i < pdata->num_ctrl; i++) {
+ int val;
+
+ val = of_get_gpio(node, i);
+ if (val < 0)
+ return val;
+ ctrl[i] = val;
+ }
+ pdata->ctrl = ctrl;
+
+ /* Get number of RPM/ctrl_val pairs in speed map */
+ prop = of_find_property(node, "gpio-fan,speed-map", &i);
+ if (!prop) {
+ dev_err(dev, "gpio-fan,speed-map DT property missing");
+ return -ENODEV;
+ }
+ i = i / sizeof(u32);
+ if (i == 0 || i & 1) {
+ dev_err(dev, "gpio-fan,speed-map contains zero/odd number of
entries");
+ return -ENODEV;
+ }
+ pdata->num_speed = i / 2;
+
+ /*
+ * Populate speed map
+ * Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
+ * this needs splitting into pairs to create gpio_fan_speed structs
+ */
+ speed = devm_kzalloc(dev,
+ pdata->num_speed * sizeof(struct gpio_fan_speed),
+ GFP_KERNEL);
+ if (!speed)
+ return -ENOMEM;
+ p = NULL;
+ for (i = 0; i < pdata->num_speed; i++) {
+ p = of_prop_next_u32(prop, p, &u);
+ if (!p)
+ return -ENODEV;
+ speed[i].rpm = u;
+ p = of_prop_next_u32(prop, p, &u);
+ if (!p)
+ return -ENODEV;
+ speed[i].ctrl_val = u;
+ }
+ pdata->speed = speed;
+
+ /* Alarm GPIO if one exists */
+ if (of_gpio_named_count(node, "alarm-gpios")) {
+ struct gpio_fan_alarm *alarm;
+ int val;
+ enum of_gpio_flags flags;
+
+ alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
+ GFP_KERNEL);
+ if (!alarm)
+ return -ENOMEM;
+
+ val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
+ if (val < 0)
+ return val;
+ alarm->gpio = val;
+ alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
+
+ pdata->alarm = alarm;
+ }
+
+ return 0;
+}
+
+static struct of_device_id of_gpio_fan_match[] __devinitdata = {
+ { .compatible = "gpio-fan", },
+ {},
+};
+#endif /* CONFIG_OF_GPIO */
+
static int __devinit gpio_fan_probe(struct platform_device *pdev)
{
int err;
struct gpio_fan_data *fan_data;
struct gpio_fan_platform_data *pdata = pdev->dev.platform_data;
+#ifdef CONFIG_OF_GPIO
+ if (!pdata) {
+ pdata = devm_kzalloc(&pdev->dev,
+ sizeof(struct gpio_fan_platform_data),
+ GFP_KERNEL);
+ if (!pdata)
+ return -ENOMEM;
+
+ err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
+ if (err)
+ return err;
+ }
+#else /* CONFIG_OF_GPIO */
if (!pdata)
return -EINVAL;
+#endif /* CONFIG_OF_GPIO */
fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
GFP_KERNEL);
@@ -511,6 +630,7 @@ static struct platform_driver gpio_fan_driver = {
.driver = {
.name = "gpio-fan",
.pm = GPIO_FAN_PM,
+ .of_match_table = of_match_ptr(of_gpio_fan_match),
},
};
--
1.7.10.4
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