On Fri, Jan 11, 2013 at 10:09:19AM -0700, Stephen Warren wrote:

On 01/10/2013 06:41 PM, Simon Glass wrote:

quoted

Some matrix keypad drivers can support different numbers of rows and
columns. Add a generic binding for these.

Implementation note:

In order to implement this binding in the kernel, we will need to modify
matrix_keypad_() to look up the number of rows and cols in
the keymap. Perhaps this could be done by passing 0 for these parameters?
Many of the parameters can already be set to NULL. Ick.

Reviewed-by: Stephen Warren <redacted>

Note that the Tegra bindings are based on matrix-keypad.txt, and
recently added the following properties:

quoted

- nvidia,kbc-row-pins: The KBC pins which are configured as row. This is an
  array of pin numbers which is used as rows.
- nvidia,kbc-col-pins: The KBC pins which are configured as column. This is an
  array of pin numbers which is used as column.

Those both define the number of rows/columns (indirectly via the
property lengths) *and* define which pins are used for the rows/columns.
How will this influence/interact-with any changes you're planning to the
core matrix keymap parsing code; would Tegra require your "new"
keypad,num-rows/keypad,num-columns properties even though the
information is redundant, or will the Tegra driver have some way of
passing this information to the core?

Even if we decide to move lookup of keypad,num-rows/keypad,num-columns
into matrix-keypad code we will still allow callers to override DT data,
like we do with platform keymaps.

Thanks.

-- 
Dmitry