Re: [PATCH] mfd: core: introduce of_node_name for mfd sub devices

From: Laxman Dewangan
Date: Thu Sep 19 2013 - 04:36:24 EST


On Thursday 19 September 2013 02:00 PM, Lee Jones wrote:
On Thu, 19 Sep 2013, Laxman Dewangan wrote:

Multi Function Devices (MFDs) have multiple sub module whose driver is
developed in different sub-system like GPIO, regulators, RTC, clock etc.
The device tree of such device contains multiple sub-node which contains
the properties of these sub-modules.

The sub module gets of_node handle either by the dev->of_node or by getting
the child node handle from parent DT handle by finding child name on parent's
of_node.

To provide the of_node of sub-module directly, currently there is only one
approach:
- Add compatible value when defining the sub-module in mfd core and
add this properties when adding DT.

Introduce the of_node_name of each sub devices which is set when defining
the mfd_cells of the sub devices and get the handle of these child node
when adding the mfd_devices by getting the sub-node handle with matching
the node name getting the sub-node handle with matching the node name.

Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
---
Creating this patch based on the discussion on patch
[PATCH 1/4] mfd: add support for AMS AS3722 PMIC
The discussion on above patch is not concluded and want to have
further discussion on this patch.
I'm not entirely sure this is what Mark was saying. I think he was
complaining about the existence of the sub-nodes rather than how the
MFD Core assigns their of_node.

Yes, Mark is only saying that he is not comfortable with the compatible until it is ip based driver.
I wanted to continue the discussion to find out the acceptable way so that I can use this in as3722 driver.

I added the of_node_name because each sub-driver gets its sub node by finding child node name from parent and hence duplicated the code on each driver.


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