diff options
| -rw-r--r-- | Documentation/devicetree/bindings/gpio/gpio-fan.txt | 25 | ||||
| -rw-r--r-- | drivers/hwmon/gpio-fan.c | 120 |
2 files changed, 145 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/gpio/gpio-fan.txt b/Documentation/devicetree/bindings/gpio/gpio-fan.txt new file mode 100644 index 000000000000..2dd457a3469a --- /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 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), }, }; |