[PATCH 1/2] [GPIOLib] GPIO Interrupt counter support
Greg KH
greg at kroah.com
Tue May 27 12:12:54 PDT 2014
On Tue, May 27, 2014 at 08:47:28PM +0200, Federico Fuga wrote:
> Interrupt counter support inside GPIOLib
What is this for? What will it provide me?
>
> Signed-off-by: Federico Fuga <fuga at studiofuga.com>
> ---
> drivers/gpio/Kconfig | 3 ++
> drivers/gpio/gpiolib.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++
> include/asm-generic/gpio.h | 6 ++++
> 3 files changed, 99 insertions(+)
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index b2450ba..d371e3c 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -81,6 +81,9 @@ config GPIO_SYSFS
> Kernel drivers may also request that a particular GPIO be
> exported to userspace; this can be useful when debugging.
>
> +config GPIO_COUNTER
> + bool "GPIO Interrupt counter (where available)"
No help text? What is this? What is it good for? Why would I want to
enable it?
> +
> config GPIO_GENERIC
> tristate
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index ff0fd65..c052cba 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -69,6 +69,10 @@ struct gpio_desc {
> #ifdef CONFIG_DEBUG_FS
> const char *label;
> #endif
> +
> +#ifdef CONFIG_GPIO_COUNTER
> + unsigned long counter; /* IRQ Events counter */
> +#endif
> };
> static struct gpio_desc gpio_desc[ARCH_NR_GPIOS];
>
> @@ -583,9 +587,55 @@ static ssize_t gpio_active_low_store(struct device *dev,
> static const DEVICE_ATTR(active_low, 0644,
> gpio_active_low_show, gpio_active_low_store);
>
> +
> +static ssize_t counter_store(struct device *dev,
> + struct device_attribute *attr, const char *buf, size_t size)
> +{
> + struct gpio_desc *desc = dev_get_drvdata(dev);
> + ssize_t status;
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (!test_bit(FLAG_EXPORT, &desc->flags)) {
> + status = -EIO;
> + } else {
> + long value;
> +
> + status = strict_strtol(buf, 0, &value);
> + if (status == 0)
> + desc->counter = value;
> + }
> +
> + mutex_unlock(&sysfs_lock);
> +
> + return status ? : size;
> +
> +}
> +
> +static ssize_t counter_show(struct device *dev,
> + struct device_attribute *attr, char *buf)
> +{
> + const struct gpio_desc *desc = dev_get_drvdata(dev);
> + ssize_t status;
> +
> + mutex_lock(&sysfs_lock);
> +
> + if (!test_bit(FLAG_EXPORT, &desc->flags))
> + status = -EIO;
> + else
> + status = sprintf(buf, "%ld\n", desc->counter);
> +
> + mutex_unlock(&sysfs_lock);
> +
> + return status;
> +}
> +static DEVICE_ATTR(counter, 0666, counter_show, counter_store);
DEVICE_ATTR_RW()?
> +
> +
> static const struct attribute *gpio_attrs[] = {
> &dev_attr_value.attr,
> &dev_attr_active_low.attr,
> + &dev_attr_counter.attr,
> NULL,
> };
>
> @@ -1114,6 +1164,46 @@ static inline void gpiod_unexport(struct gpio_desc *desc)
>
> #endif /* CONFIG_GPIO_SYSFS */
>
> +#ifdef CONFIG_GPIO_COUNTER
> +int gpio_counter_inc (unsigned gpio)
Trailing whitespace :(
> +{
> + struct gpio_desc *desc = gpio_to_desc(gpio);
> +
> + mutex_lock(&sysfs_lock);
> + desc->counter++;
> + mutex_unlock(&sysfs_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(gpio_counter_inc);
> +
> +long gpio_counter_get (unsigned gpio)
> +{
> + long ret;
> + struct gpio_desc *desc = gpio_to_desc(gpio);
> +
> + mutex_lock(&sysfs_lock);
> + ret = desc->counter;
> + mutex_unlock(&sysfs_lock);
> +
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(gpio_counter_get);
> +
> +int gpio_counter_set (unsigned gpio, long value)
> +{
> + struct gpio_desc *desc = gpio_to_desc(gpio);
> +
> + mutex_lock(&sysfs_lock);
> + desc->counter = value;
> + mutex_unlock(&sysfs_lock);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(gpio_counter_set);
> +#endif
> +
> +
> /*
> * Add a new chip to the global chips list, keeping the list of chips sorted
> * by base order.
> diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
> index bde6469..2d40187 100644
> --- a/include/asm-generic/gpio.h
> +++ b/include/asm-generic/gpio.h
> @@ -210,6 +210,12 @@ extern void gpio_unexport(unsigned gpio);
>
> #endif /* CONFIG_GPIO_SYSFS */
>
> +#ifdef CONFIG_GPIO_COUNTER
> +extern int gpio_counter_inc (unsigned gpio);
> +extern long gpio_counter_get (unsigned gpio);
> +extern int gpio_counter_set (unsigned gpio, long value);
> +#endif
Provide versions here that are "empty" if the option is not enabled.
thanks,
greg k-h
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