On Fri, Jul 17, 2015 at 11:32:49AM +0200, Markus Pargmann wrote:
> This patch adds a sysfs attribute 'name' to gpios that were exported. It
> exposes the newly added name property of gpio descriptors.
>
> Signed-off-by: Markus Pargmann <m...@pengutronix.de>
> ---
> drivers/gpio/gpiolib-sysfs.c | 20 ++++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> index c3b74440ca67..058019879bab 100644
> --- a/drivers/gpio/gpiolib-sysfs.c
> +++ b/drivers/gpio/gpiolib-sysfs.c
> @@ -139,6 +139,25 @@ static ssize_t value_store(struct device *dev,
> }
> static DEVICE_ATTR_RW(value);
>
> +static ssize_t gpio_name_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + struct gpio_desc *desc = dev_get_drvdata(dev);
> + ssize_t status;
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (!test_bit(FLAG_EXPORT, &desc->flags))
No need to check flag export, and no need for the mutex either.
> + status = -EIO;
> + else
> + status = sprintf(buf, "%s\n", desc->name);
Depending on sprintfs representation of NULL is not a good idea here.
> +
> + mutex_unlock(&sysfs_lock);
> + return status;
> +}
> +
> +static DEVICE_ATTR(name, 0444, gpio_name_show, NULL);
DEVICE_ATTR_RO
> +
> static irqreturn_t gpio_sysfs_irq(int irq, void *priv)
> {
> struct gpiod_data *data = priv;
> @@ -377,6 +396,7 @@ static struct attribute *gpio_attrs[] = {
> &dev_attr_edge.attr,
> &dev_attr_value.attr,
> &dev_attr_active_low.attr,
> + &dev_attr_name.attr,
> NULL,
> };
Johan
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