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>

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),
         },
 };