Commit 55fb8b06 authored by Jamie Lentin's avatar Jamie Lentin Committed by Jason Cooper

hwmon: Add devicetree bindings to gpio-fan

Allow a gpio-fan to be defined in devicetree, see binding documentation
for details.
Signed-off-by: default avatarJamie Lentin <jm@lentin.co.uk>
Acked-by: default avatarAndrew Lunn <andrew@lunn.ch>
Acked-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarJason Cooper <jason@lakedaemon.net>
parent f37fbd36
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>;
};
...@@ -31,6 +31,8 @@ ...@@ -31,6 +31,8 @@
#include <linux/hwmon.h> #include <linux/hwmon.h>
#include <linux/gpio.h> #include <linux/gpio.h>
#include <linux/gpio-fan.h> #include <linux/gpio-fan.h>
#include <linux/of_platform.h>
#include <linux/of_gpio.h>
struct gpio_fan_data { struct gpio_fan_data {
struct platform_device *pdev; struct platform_device *pdev;
...@@ -400,14 +402,131 @@ static ssize_t show_name(struct device *dev, ...@@ -400,14 +402,131 @@ static ssize_t show_name(struct device *dev,
static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); 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) static int __devinit gpio_fan_probe(struct platform_device *pdev)
{ {
int err; int err;
struct gpio_fan_data *fan_data; struct gpio_fan_data *fan_data;
struct gpio_fan_platform_data *pdata = pdev->dev.platform_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) if (!pdata)
return -EINVAL; return -EINVAL;
#endif /* CONFIG_OF_GPIO */
fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data), fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
GFP_KERNEL); GFP_KERNEL);
...@@ -511,6 +630,7 @@ static struct platform_driver gpio_fan_driver = { ...@@ -511,6 +630,7 @@ static struct platform_driver gpio_fan_driver = {
.driver = { .driver = {
.name = "gpio-fan", .name = "gpio-fan",
.pm = GPIO_FAN_PM, .pm = GPIO_FAN_PM,
.of_match_table = of_match_ptr(of_gpio_fan_match),
}, },
}; };
......
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