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SubjectRe: [PATCH 15/19] mc13xxx: mfd_cell is now implicitly available to drivers

On Fri, Feb 04, 2011 at 10:34:58AM +0100, Uwe Kleine-König wrote:
> And I think this patch has a conceptual problem, too. In my opionion
> platform_data is the point to hand over platform specific data to a
> driver. driver_data is something that is private to the driver and has
> to be considered opaque for the platform. The driver was sort of OK
> before ...

So consequently I propose the patch below. I'm sure that a few drivers
will break, but IMHO that's OK.

And by the way, did you know that platform_set_drvdata can fail and you
have no nice way to notice that but to do:

dev_set_drvdata(dev, mypreciousdata);
if (dev_get_drvdata(dev) != mypreciousdata)
goto fail;

Best regards

From: Uwe Kleine-König <>
Date: Fri, 4 Feb 2011 11:00:42 +0100
Subject: [PATCH] MFD: platform_set_drvdata should be only called by drivers

driver data is data private to drivers so it's not a point to hand over
data to the driver by the platform. That's what platform_data is available
for. The only place platform_set_drvdata should be called is in a
driver that has bound the device in question.

Signed-off-by: Uwe Kleine-König <>
drivers/mfd/mfd-core.c | 1 -
include/linux/mfd/core.h | 3 ---
2 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c
index d83ad0f..8d06e0c 100644
--- a/drivers/mfd/mfd-core.c
+++ b/drivers/mfd/mfd-core.c
@@ -37,7 +37,6 @@ static int mfd_add_device(struct device *parent, int id,
goto fail_device;

pdev->dev.parent = parent;
- platform_set_drvdata(pdev, cell->driver_data);

if (cell->data_size) {
ret = platform_device_add_data(pdev,
diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h
index 835996e..88bb7b5 100644
--- a/include/linux/mfd/core.h
+++ b/include/linux/mfd/core.h
@@ -30,9 +30,6 @@ struct mfd_cell {
int (*suspend)(struct platform_device *dev);
int (*resume)(struct platform_device *dev);

- /* driver-specific data for MFD-aware "cell" drivers */
- void *driver_data;
/* platform_data can be used to either pass data to "generic"
driver or as a hook to mfd_cell for the "cell" drivers */
void *platform_data;
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | |
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