Allow a gpio-fan to be defined in devicetree, see binding documentation for details.
Signed-off-by: Jamie Lentin <[email protected]> --- .../devicetree/bindings/gpio/gpio-fan.txt | 25 +++++ drivers/hwmon/gpio-fan.c | 111 ++++++++++++++++++++ 2 files changed, 136 insertions(+) create mode 100644 Documentation/devicetree/bindings/gpio/gpio-fan.txt diff --git a/Documentation/devicetree/bindings/gpio/gpio-fan.txt b/Documentation/devicetree/bindings/gpio/gpio-fan.txt new file mode 100644 index 0000000..2dd457a --- /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 2f4b01b..876ce41 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; @@ -400,12 +402,120 @@ static ssize_t show_name(struct device *dev, static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); + +#ifdef CONFIG_OF +/* + * 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); + ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned), + GFP_KERNEL); + if (!ctrl) + return -ENOMEM; + for (i = 0; i < of_gpio_count(node); i++) { + int val; + + val = of_get_gpio(node, i); + if (val >= 0) + ctrl[i] = val; + else + return -EINVAL; + } + pdata->ctrl = ctrl; + + /* Get speed map array size */ + i = 0; + of_property_for_each_u32(node, "gpio-fan,speed-map", prop, p, u) + i++; + if (i & 1) { + dev_err(dev, "gpio-fan,speed-map contains odd number of entries"); + return -ENODEV; + } + pdata->num_speed = i >> 1; + speed = devm_kzalloc(dev, + pdata->num_speed * sizeof(struct gpio_fan_speed), + GFP_KERNEL); + if (!speed) + return -ENOMEM; + + /* Populate speed map */ + i = 0; + of_property_for_each_u32(node, "gpio-fan,speed-map", prop, p, u) { + if (i & 1) + speed[i >> 1].ctrl_val = (int)u; + else + speed[i >> 1].rpm = (int)u; + i++; + } + 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) { + alarm->gpio = val; + alarm->active_low = flags & OF_GPIO_ACTIVE_LOW; + } else + return -EINVAL; + + pdata->alarm = alarm; + } + + return 0; +} + +static const struct of_device_id of_gpio_fan_match[] = { + { .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 + if (!pdata) { + struct gpio_fan_platform_data *alt_pdata; + + alt_pdata = devm_kzalloc(&pdev->dev, + sizeof(struct gpio_fan_platform_data), + GFP_KERNEL); + if (!alt_pdata) + return -ENOMEM; + + err = gpio_fan_get_of_pdata(&pdev->dev, alt_pdata); + if (err) + return err; + pdata = alt_pdata; + } +#endif /* CONFIG_OF_GPIO */ + if (!pdata) return -EINVAL; @@ -511,6 +621,7 @@ 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), }, }; -- 1.7.10.4 _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
