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authorJamie Lentin <jm@lentin.co.uk>2012-09-14 20:07:06 +0400
committerJason Cooper <jason@lakedaemon.net>2012-09-22 18:40:49 +0400
commit55fb8b06813b190a9366fee396fac109638a9c9d (patch)
treebdb224ab7df6228fed8ec0e4b716a3ce697ee99c /drivers/hwmon/gpio-fan.c
parentf37fbd36c5f9fe716ddf783415a67de03fb0dc3d (diff)
downloadlinux-55fb8b06813b190a9366fee396fac109638a9c9d.tar.xz
hwmon: Add devicetree bindings to gpio-fan
Allow a gpio-fan to be defined in devicetree, see binding documentation for details. Signed-off-by: Jamie Lentin <jm@lentin.co.uk> Acked-by: Andrew Lunn <andrew@lunn.ch> Acked-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'drivers/hwmon/gpio-fan.c')
-rw-r--r--drivers/hwmon/gpio-fan.c120
1 files changed, 120 insertions, 0 deletions
diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c
index 2f4b01bda87c..36509ae32083 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),
},
};