Thread (10 messages) flat view 10 messages, 3 authors, 2017-02-21

[RESEND PATCH 1/3] mtd: nand: Pass the CS line to ->setup_data_interface()

From: Marc Gonzalez <hidden>
Date: 2017-02-21 12:03:44
Also in: lkml

On 21/02/2017 12:06, Boris Brezillon wrote:
Marc Gonzalez wrote:
quoted
On 20/02/2017 22:12, Boris Brezillon wrote:
quoted
Some NAND controllers can assign different NAND timings to different
CS lines. Pass the CS line information to ->setup_data_interface() so
that the NAND controller driver knows which CS line is concerned by
the setup_data_interface() request.  
I'm confused, because I thought I was already doing that.
On my platform, I have different timings for each chip.
(thus, for each CS, right?)

In chip->select_chip, I program the appropriate timings
which the controller will be using.

What am I missing?
Maybe you don't have multi-dies chips, which is the case I'm fixing
here. If you have 2 separate chips, the existing hook should work just
fine.
Right. You asked me to add an explicit:

	res = of_property_count_u32_elems(np, "reg");
	if (res < 0)
		return res;

	if (res != 1)
		return -ENOTSUPP; /* Multi-CS chips are not supported */

I was under the impression that multi-die chips are seen as a single
larger "composite" chip. And I had assumed that different dies would
not only require identical timings, but would also be identical in
all other aspects. This it incorrect?

Regards.
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