[PATCH 1/3] mfd: always assign of_node in mfd_add_device()

[Lee Jones]

> From: Stephen Warren <swarren at nvidia.com>
> 
> mfd_add_device() assigns .of_node in the device objects it creates only
> if the mfd_cell for the device has the .of_compatible field set and the
> DT node for the top-level MFD device contains a child whose compatible
> property matches the cell's .of_compatible field.
> 
> This leaves .of_node unset in many cases. When this happens, entries in
> the DT /aliases property which refer to the top-level MFD DT node will
> never match the MFD child devices, hence causing the requested alias not
> to be honored.
> 
> Solve this by setting each MFD child device's .of_node equal to the top-
> level MFD device's .of_node field in the cases where it would otherwise
> remain unset.

How sure are you that this will be void of repercussions?

> The first use-case for this will be aliases for the TPS6586x's RTC
> device.

Isn't it viable to supply the of_compatible strings for these nodes
and search the parent for its alias property instead?

> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> ---
> The 3 patches in this series are all independent; they can be applied
> to their respective subsystems in any order. I'm simply posting them as
> a series to make the use-case more obvious.
> ---
>  drivers/mfd/mfd-core.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
> index 267649244737..32e8d47d9002 100644
> --- a/drivers/mfd/mfd-core.c
> +++ b/drivers/mfd/mfd-core.c
> @@ -117,6 +117,8 @@ static int mfd_add_device(struct device *parent, int id,
>  			}
>  		}
>  	}
> +	if (!pdev->dev.of_node)
> +		pdev->dev.of_node = parent->of_node;
>  
>  	if (cell->pdata_size) {
>  		ret = platform_device_add_data(pdev,

-- 
Lee Jones
Linaro STMicroelectronics Landing Team Lead
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