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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>
This commit is contained in:
Jamie Lentin
Jason Cooper
parent
f37fbd36c5
commit
55fb8b0681
25
Documentation/devicetree/bindings/gpio/gpio-fan.txt
Normal file
25
Documentation/devicetree/bindings/gpio/gpio-fan.txt
Normal file
@ -0,0 +1,25 @@
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Bindings for fan connected to GPIO lines
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Required properties:
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- compatible : "gpio-fan"
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- gpios: Specifies the pins that map to bits in the control value,
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ordered MSB-->LSB.
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- gpio-fan,speed-map: A mapping of possible fan RPM speeds and the
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control value that should be set to achieve them. This array
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must have the RPM values in ascending order.
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Optional properties:
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- alarm-gpios: This pin going active indicates something is wrong with
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the fan, and a udev event will be fired.
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Examples:
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gpio_fan {
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compatible = "gpio-fan";
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gpios = <&gpio1 14 1
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&gpio1 13 1>;
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gpio-fan,speed-map = <0 0
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3000 1
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6000 2>;
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alarm-gpios = <&gpio1 15 1>;
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};
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@ -31,6 +31,8 @@
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#include <linux/hwmon.h>
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#include <linux/gpio.h>
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#include <linux/gpio-fan.h>
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#include <linux/of_platform.h>
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#include <linux/of_gpio.h>
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struct gpio_fan_data {
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struct platform_device *pdev;
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@ -400,14 +402,131 @@ static ssize_t show_name(struct device *dev,
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static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
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#ifdef CONFIG_OF_GPIO
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/*
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* Translate OpenFirmware node properties into platform_data
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*/
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static int gpio_fan_get_of_pdata(struct device *dev,
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struct gpio_fan_platform_data *pdata)
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{
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struct device_node *node;
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struct gpio_fan_speed *speed;
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unsigned *ctrl;
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unsigned i;
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u32 u;
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struct property *prop;
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const __be32 *p;
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node = dev->of_node;
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/* Fill GPIO pin array */
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pdata->num_ctrl = of_gpio_count(node);
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if (!pdata->num_ctrl) {
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dev_err(dev, "gpios DT property empty / missing");
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return -ENODEV;
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}
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ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned),
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GFP_KERNEL);
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if (!ctrl)
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return -ENOMEM;
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for (i = 0; i < pdata->num_ctrl; i++) {
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int val;
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val = of_get_gpio(node, i);
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if (val < 0)
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return val;
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ctrl[i] = val;
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}
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pdata->ctrl = ctrl;
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/* Get number of RPM/ctrl_val pairs in speed map */
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prop = of_find_property(node, "gpio-fan,speed-map", &i);
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if (!prop) {
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dev_err(dev, "gpio-fan,speed-map DT property missing");
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return -ENODEV;
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}
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i = i / sizeof(u32);
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if (i == 0 || i & 1) {
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dev_err(dev, "gpio-fan,speed-map contains zero/odd number of entries");
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return -ENODEV;
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}
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pdata->num_speed = i / 2;
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/*
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* Populate speed map
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* Speed map is in the form <RPM ctrl_val RPM ctrl_val ...>
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* this needs splitting into pairs to create gpio_fan_speed structs
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*/
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speed = devm_kzalloc(dev,
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pdata->num_speed * sizeof(struct gpio_fan_speed),
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GFP_KERNEL);
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if (!speed)
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return -ENOMEM;
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p = NULL;
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for (i = 0; i < pdata->num_speed; i++) {
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p = of_prop_next_u32(prop, p, &u);
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if (!p)
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return -ENODEV;
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speed[i].rpm = u;
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p = of_prop_next_u32(prop, p, &u);
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if (!p)
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return -ENODEV;
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speed[i].ctrl_val = u;
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}
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pdata->speed = speed;
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/* Alarm GPIO if one exists */
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if (of_gpio_named_count(node, "alarm-gpios")) {
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struct gpio_fan_alarm *alarm;
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int val;
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enum of_gpio_flags flags;
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alarm = devm_kzalloc(dev, sizeof(struct gpio_fan_alarm),
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GFP_KERNEL);
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if (!alarm)
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return -ENOMEM;
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val = of_get_named_gpio_flags(node, "alarm-gpios", 0, &flags);
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if (val < 0)
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return val;
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alarm->gpio = val;
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alarm->active_low = flags & OF_GPIO_ACTIVE_LOW;
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pdata->alarm = alarm;
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}
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return 0;
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}
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static struct of_device_id of_gpio_fan_match[] __devinitdata = {
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{ .compatible = "gpio-fan", },
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{},
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};
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#endif /* CONFIG_OF_GPIO */
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static int __devinit gpio_fan_probe(struct platform_device *pdev)
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{
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int err;
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struct gpio_fan_data *fan_data;
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struct gpio_fan_platform_data *pdata = pdev->dev.platform_data;
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#ifdef CONFIG_OF_GPIO
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if (!pdata) {
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pdata = devm_kzalloc(&pdev->dev,
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sizeof(struct gpio_fan_platform_data),
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GFP_KERNEL);
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if (!pdata)
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return -ENOMEM;
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err = gpio_fan_get_of_pdata(&pdev->dev, pdata);
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if (err)
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return err;
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}
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#else /* CONFIG_OF_GPIO */
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if (!pdata)
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return -EINVAL;
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#endif /* CONFIG_OF_GPIO */
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fan_data = devm_kzalloc(&pdev->dev, sizeof(struct gpio_fan_data),
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GFP_KERNEL);
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@ -511,6 +630,7 @@ static struct platform_driver gpio_fan_driver = {
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.driver = {
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.name = "gpio-fan",
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.pm = GPIO_FAN_PM,
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.of_match_table = of_match_ptr(of_gpio_fan_match),
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},
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};
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