Re: [PATCH] memory: add a basic OF-based memory driver

On Sun, Sep 15, 2013 at 7:43 AM, Grant Likely [off-list ref] wrote:

On Fri, 13 Sep 2013 08:49:06 -0700, Olof Johansson [off-list ref] wrote:

quoted

On Fri, Sep 13, 2013 at 7:00 AM, Rob Herring [off-list ref] wrote:

quoted

On Thu, Sep 12, 2013 at 8:31 PM, Emilio López [off-list ref] wrote:

[snip]

quoted

quoted

Better, but this is still wrong. DT describes the hardware. There is
no such h/w as a simple-memory-controller. The fact that you have a
simple-memory-ctrlr kernel driver is a kernel
feature/artifact/limitation. Describe the h/w with a meaningful
compatible string and put that string in the simple memory controller
driver match table. If someday we have a real driver for said memory
controller, then it is only a kernel change to use a different driver.

We discussed this over IRC last night -- I still think it makes more
sense to make the clock driver for sunxi aware of this and just add a
reference to the clock at init time.

This is never going to differ from board to board (today the clock
name is the same on all sunxi platforms -- pll5_ddr. And the need will
likewise be there for all platforms at this time.

If and when it changes in the future, we can reevaluate. But this
doesn't have to be driven by device tree at this time, it seems to
just make things overly complicated and contrived.

I agree. Creating a new platform driver + device tree binding just to
claim a clock that must not be disables does not look like the right
approach to me either.

Maybe a driver is overkill, but fully describing the h/w would be a
good thing. Only defining the h/w that Linux currently uses is not a
good practice (although admittedly hard to avoid).

Rob
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