platform data and mfd design question

From: Abhijeet Dharmapurikar
Date: Tue Feb 15 2011 - 16:51:30 EST


Currently all the mfd devices declare their struct mfd_cell sub_devices[] array within the core driver. The platform data to them is either passed in as a part of the core driver's platform data.

Msm on the other hand declares the struct mfd_cell subdevice[] array in the board file and passes this on to the core driver via platfom data.
This code can be found here (sorry for the long url - it is convinient to click on it),
https://www.codeaurora.org/gitweb/quic/la/?p=kernel/msm.git;a=blob;f=arch/arm/mach-msm/board-msm8x60.c;h=ed9e9a7674b5ee443f25af828a0044ff99fac483;hb=refs/heads/android-msm-2.6.35
look for static struct mfd_cell pm8058_subdevs[]

This gives one the convenience of changing the mfd_cells and their platform data in the board file itself. There are boards where the platform data of some cells changes and in some cases we dont even add a particular cell.

This design makes the core driver very light weight. All it does is calls mfd_add_devices on the cell array passed from its platform data.

Will this be acceptable in mainline OR do we need to change to follow how others in drivers/mfd do it which is to define the mfd_cell array in the core file itself and manipulate their platform data before doing mfd_add_devices.


--
Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/