Re: [PATCH RESEND] gpio: lib-sysfs: Add 'wakeup' attribute

From: SÃren Brinkmann
Date: Tue Oct 07 2014 - 16:28:44 EST


Hi Linus,

just wanted to check on the status of this patch?

Thanks,
SÃren

On Thu, 2014-09-04 at 10:58AM -0700, Soren Brinkmann wrote:
> Add an attribute 'wakeup' to the GPIO sysfs interface which allows
> marking/unmarking a GPIO as wake IRQ.
> The file 'wakeup' is created in each exported GPIOs directory, if an IRQ
> is associated with that GPIO and the irqchip implements set_wake().
> Writing 'enabled' to that file will enable wake for that GPIO, while
> writing 'disabled' will disable wake.
> Reading that file will return either 'disabled' or 'enabled' depening on
> the currently set flag for the GPIO's IRQ.
>
> Signed-off-by: Soren Brinkmann <soren.brinkmann@xxxxxxxxxx>
> ---
> Hi all,
>
> I originally submitted this patch with a few fixes for Zynq's GPIO driver
> (https://lkml.org/lkml/2014/8/29/391). Since this change is not just
> Zynq-related and has broader impact, Linus asked me to post this again, separate
> from the Zynq series.
>
> Let me just quote myself from the original submission:
> "I'm still not fully convinced that the gpio_keys are the best
> replacement for the sysfs interface when it comes to inputs. For that
> reason and to have a way to do some quick wake testing, I'd like to
> propose adding the ability to control wake through the sysfs interface
> (patch 3)."
>
> Thanks,
> SÃren
>
> drivers/gpio/gpiolib-sysfs.c | 75 ++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 69 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
> index 5f2150b619a7..aaf021eaaff5 100644
> --- a/drivers/gpio/gpiolib-sysfs.c
> +++ b/drivers/gpio/gpiolib-sysfs.c
> @@ -286,6 +286,56 @@ found:
>
> static DEVICE_ATTR(edge, 0644, gpio_edge_show, gpio_edge_store);
>
> +static ssize_t gpio_wakeup_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + ssize_t status;
> + const struct gpio_desc *desc = dev_get_drvdata(dev);
> + int irq = gpiod_to_irq(desc);
> + struct irq_desc *irq_desc = irq_to_desc(irq);
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (irqd_is_wakeup_set(&irq_desc->irq_data))
> + status = sprintf(buf, "enabled\n");
> + else
> + status = sprintf(buf, "disabled\n");
> +
> + mutex_unlock(&sysfs_lock);
> +
> + return status;
> +}
> +
> +static ssize_t gpio_wakeup_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t size)
> +{
> + int ret;
> + unsigned int on;
> + struct gpio_desc *desc = dev_get_drvdata(dev);
> + int irq = gpiod_to_irq(desc);
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (sysfs_streq("enabled", buf))
> + on = true;
> + else if (sysfs_streq("disabled", buf))
> + on = false;
> + else
> + return -EINVAL;
> +
> + ret = irq_set_irq_wake(irq, on);
> +
> + mutex_unlock(&sysfs_lock);
> +
> + if (ret)
> + pr_warn("%s: failed to %s wake\n", __func__,
> + on ? "enable" : "disable");
> +
> + return size;
> +}
> +
> +static DEVICE_ATTR(wakeup, 0644, gpio_wakeup_show, gpio_wakeup_store);
> +
> static int sysfs_set_active_low(struct gpio_desc *desc, struct device *dev,
> int value)
> {
> @@ -526,7 +576,7 @@ static struct class gpio_class = {
> int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
> {
> unsigned long flags;
> - int status;
> + int status, irq;
> const char *ioname = NULL;
> struct device *dev;
> int offset;
> @@ -582,11 +632,24 @@ int gpiod_export(struct gpio_desc *desc, bool direction_may_change)
> goto fail_unregister_device;
> }
>
> - if (gpiod_to_irq(desc) >= 0 && (direction_may_change ||
> - !test_bit(FLAG_IS_OUT, &desc->flags))) {
> - status = device_create_file(dev, &dev_attr_edge);
> - if (status)
> - goto fail_unregister_device;
> + irq = gpiod_to_irq(desc);
> + if (irq >= 0) {
> + struct irq_desc *irq_desc = irq_to_desc(irq);
> + struct irq_chip *irqchip = irq_desc_get_chip(irq_desc);
> +
> + if (direction_may_change ||
> + !test_bit(FLAG_IS_OUT, &desc->flags)) {
> + status = device_create_file(dev, &dev_attr_edge);
> + if (status)
> + goto fail_unregister_device;
> + }
> +
> + if (irqchip->flags & IRQCHIP_SKIP_SET_WAKE ||
> + irqchip->irq_set_wake) {
> + status = device_create_file(dev, &dev_attr_wakeup);
> + if (status)
> + goto fail_unregister_device;
> + }
> }
>
> set_bit(FLAG_EXPORT, &desc->flags);
> --
> 2.1.0.1.g27b9230
>
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