Re: [PATCH/RFC] mfd: Allow multiple MFD cells with the same name

From: Mark Brown
Date: Mon Jul 13 2009 - 07:30:26 EST


On Thu, Jul 02, 2009 at 05:06:38PM +0100, Mark Brown wrote:
> Provide basic support for MFDs having multiple cells of a given
> type with different IDs by adding an id to the mfd_cell structure
> and then adding that to the id passed in to mfd_add_devices().
>
> As it stands this approach requires that MFDs using this feature
> deal with ensuring that there aren't any ID collisions resulting
> from multiple MFDs of the same type being instantiated. This needs
> to happen with the existing code too, but with this approach there
> is a knock on effect on the IDs for non-duplicated devices.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

Samuel, do you have any thoughts on this patch? As I said...

> I'm not 100% convinced that this is the best way to do this but I can't
> think of anything better

...but it'd be really helpful to get some idea if this approach is going
to be viable for some code I'm currently working on.

>
> drivers/mfd/mfd-core.c | 2 +-
> include/linux/mfd/core.h | 1 +
> 2 files changed, 2 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 54ddf37..ae15e49 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -25,7 +25,7 @@ static int mfd_add_device(struct device *parent, int id,
> int ret = -ENOMEM;
> int r;
>
> - pdev = platform_device_alloc(cell->name, id);
> + pdev = platform_device_alloc(cell->name, id + cell->id);
> if (!pdev)
> goto fail_alloc;
>
> diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
> index 49ef857..11d740b 100644
> --- a/include/linux/mfd/core.h
> +++ b/include/linux/mfd/core.h
> @@ -23,6 +23,7 @@
> */
> struct mfd_cell {
> const char *name;
> + int id;
>
> int (*enable)(struct platform_device *dev);
> int (*disable)(struct platform_device *dev);
> --
> 1.6.3.3
>
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