Re: [PATCH v7][ 3/5] video: mx3fb: Introduce regulator support.

On Tue, Jun 10, 2014 at 03:29:33PM +0200, Denis Carikli wrote:

On 03/17/2014 07:20 AM, Sascha Hauer wrote:

quoted

This patch adds regulator support for the display of a i.MX3 IPU. The
problem Denis has to solve here is that he needs to get the regulator,
but the display devicenode doesn't have a struct device associated with
it, so he cannot provide one to regulator_get(). One way out here could
be a of_regulator_get(struct device_node *). Mark, would this be ok with
you?

Here, the display devicenode has no struct device associated with it like
mentioned above.
Because of that, retriving the regulator from the devicetree, for instance
like regulator_dev_lookup() does, would require a different approach.

As I understand it, what happen in regulator_dev_lookup when
regulator_get(NULL, regulator_name) is used is the following:

Since the struct device is NULL, it skips the struct device based lookup,
but also the devicetree lookup (it uses dev->of_node for that)
At the end it falls back on a match on the regulator name to find it.

would keeping regulator_get(NULL, regulator_name); in the driver instead be
better for now?

It would be much better to have an actual device to get things for,
using a hard coded regulator name is very much deprecated.  Using a hard
coded name is fragile and we don't have support for mapping this
properly in the device tree.