On Thu, Dec 29, 2011 at 1:14 PM, Rob Herring <robherring2@xxxxxxxxx> wrote: > On 12/29/2011 12:42 PM, Olof Johansson wrote: >> This adds a simple device tree binding for simple key matrix data. >> >> Changes since v1: >> * Removed samsung-style binding support >> * Added linux,fn-keymap and linux,fn-key optional properties >> >> Signed-off-by: Olof Johansson <olof@xxxxxxxxx> >> --- >> .../devicetree/bindings/input/matrix-keymap.txt | 25 ++++++ >> drivers/input/keyboard/Makefile | 1 + >> drivers/input/keyboard/keymap.c | 78 ++++++++++++++++++++ >> include/linux/input/matrix_keypad.h | 34 +++++---- >> 4 files changed, 123 insertions(+), 15 deletions(-) >> create mode 100644 Documentation/devicetree/bindings/input/matrix-keymap.txt >> create mode 100644 drivers/input/keyboard/keymap.c >> >> diff --git a/Documentation/devicetree/bindings/input/matrix-keymap.txt b/Documentation/devicetree/bindings/input/matrix-keymap.txt >> new file mode 100644 >> index 0000000..480ca46 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/input/matrix-keymap.txt >> @@ -0,0 +1,25 @@ >> +For matrix keyboards there are two kinds of layout bindings using >> +linux key codes. > > Need to update this. Oops, yes. >> + >> +Required properties: >> +- compatible: "matrix-keyboard-controller" >> +- linux,keymap: an array of 3-cell entries containing the equivalent >> + of the three separate properties above: row, column and linux >> + key-code. >> + > > How about just embedding the row/column information as the array > position in the keymap? Then you only need 1 cell per key. Sparsely > populated matrices are probably the exception. If more than 1/3 of the > keys are present, you come out ahead in terms of data usage. You would > need to specify the number of rows and columns, but that is probably > easier than determining the max from the keymap. Actually, in the case of the default layout for tegra-kbc, there are 109 keys defined in a 8*31 (248) matrix, and linux,fn-keymap is going to be much sparser than that. Instead, how about packing the row, column and index into one cell as 8, 8, 16 bits? That would be a win for both sparse and dense maps. Number of rows and columns for the keyboard could be provided as properties (num-rows, num-columns), it's something I've gone back and forth in whether it should be in the generic binding or something that is specific per keyboard vendor -- some of them are hardcoded so providing properties might not add value. -Olof -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
