Re: [PATCH 1/7] driver-core : add class iteration api

Jarek Poplawski
2008-01-12T20:08:03Z

On Sat, Jan 12, 2008 at 05:47:54PM +0800, Dave Young wrote:
> Add the following class iteration functions for driver use:
> class_for_each_device
> class_find_device
> class_for_each_child
> class_find_child
>
> Signed-off-by: Dave Young <hidave.darkstar@gmail.com>
>
> ---
> drivers/base/class.c | 159 +++++++++++++++++++++++++++++++++++++++++++++++++
> include/linux/device.h | 8 ++
> 2 files changed, 167 insertions(+)
>
> diff -upr linux/drivers/base/class.c linux.new/drivers/base/class.c
> --- linux/drivers/base/class.c 2008-01-12 14:42:24.000000000 +0800
> +++ linux.new/drivers/base/class.c 2008-01-12 14:42:24.000000000 +0800
> @@ -798,6 +798,165 @@ void class_device_put(struct class_devic
> kobject_put(&class_dev->kobj);
> }
>
> +/**
> + * class_for_each_device - device iterator
> + * @class: the class we're iterating
> + * @data: data for the callback
> + * @fn: function to be called for each device
> + *
> + * Iterate over @class's list of devices, and call @fn for each,
> + * passing it @data.
> + *
> + * We check the return of @fn each time. If it returns anything
> + * other than 0, we break out and return that value.
> + */
> +int class_for_each_device(struct class *class, void *data,
> + int (*fn)(struct device *, void *))
> +{
> + struct device *dev;
> + int error = 0;
> +
> + if (!class)
> + return -EINVAL;
> + down(&class->sem);
> + list_for_each_entry(dev, &class->devices, node) {

Probably some tiny oversight, but I see this comment to struct class
doesn't mention devices list, so maybe this needs to be updated BTW?:

(from include/linux/device.h)
" struct semaphore sem; /* locks both the children and interfaces lists */"

Regards,
Jarek P.