From 73ef85f42da2df8b567fea109c67ed53db937bcc Mon Sep 17 00:00:00 2001 From: Simon Guinot Date: Wed, 25 Feb 2015 18:58:19 +0100 Subject: [PATCH] hwmon: (gpio-fan) allow to use alarm support alone from DT On some boards, such as the LaCie 2Big Network v2 or 2Big NAS (based on Marvell Kirkwood SoCs), an I2C fan controller is used but the alarm signal is wired to a separate GPIO. Unfortunately, the gpio-fan driver can't be used to handle GPIO alarm alone from DT: an error is returned if the "gpios" DT property is missing. This patch allows to use the gpio-fan driver even if the "alarm-gpios" DT property is defined alone. Signed-off-by: Simon Guinot Signed-off-by: Guenter Roeck --- .../devicetree/bindings/gpio/gpio-fan.txt | 6 ++- drivers/hwmon/gpio-fan.c | 44 ++++++++++--------- 2 files changed, 27 insertions(+), 23 deletions(-) diff --git a/Documentation/devicetree/bindings/gpio/gpio-fan.txt b/Documentation/devicetree/bindings/gpio/gpio-fan.txt index 2dd457a3469a..f996d428f132 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-fan.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-fan.txt @@ -2,16 +2,18 @@ Bindings for fan connected to GPIO lines Required properties: - compatible : "gpio-fan" + +Optional properties: - 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. +Note: At least one the "gpios" or "alarm-gpios" properties must be set. + Examples: gpio_fan { diff --git a/drivers/hwmon/gpio-fan.c b/drivers/hwmon/gpio-fan.c index 36abf814b8c7..c241f5b0b7cf 100644 --- a/drivers/hwmon/gpio-fan.c +++ b/drivers/hwmon/gpio-fan.c @@ -404,10 +404,32 @@ static int gpio_fan_get_of_pdata(struct device *dev, node = dev->of_node; + /* Alarm GPIO if one exists */ + if (of_gpio_named_count(node, "alarm-gpios") > 0) { + 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; + } + /* Fill GPIO pin array */ pdata->num_ctrl = of_gpio_count(node); if (pdata->num_ctrl <= 0) { - dev_err(dev, "gpios DT property empty / missing"); + if (pdata->alarm) + return 0; + dev_err(dev, "DT properties empty / missing"); return -ENODEV; } ctrl = devm_kzalloc(dev, pdata->num_ctrl * sizeof(unsigned), @@ -460,26 +482,6 @@ static int gpio_fan_get_of_pdata(struct device *dev, } pdata->speed = speed; - /* Alarm GPIO if one exists */ - if (of_gpio_named_count(node, "alarm-gpios") > 0) { - 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; } -- 2.39.2