cros: adds cros_ec keyboard driver

This patch adds the driver for keyboard that's controlled by ChromeOS EC.

Signed-off-by: Randall Spangler <rspangler@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Vincent Palatin <vpalatin@chromium.org>
Signed-off-by: Hung-ying Tyan <tyanh@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/device-tree-bindings/input/cros-ec-keyb.txt b/doc/device-tree-bindings/input/cros-ec-keyb.txt
new file mode 100644
index 0000000..3118276
--- /dev/null
+++ b/doc/device-tree-bindings/input/cros-ec-keyb.txt
@@ -0,0 +1,79 @@
+CROS_EC Keyboard
+
+The CROS_EC (Matrix Keyboard Protocol) allows communcation with a secondary
+micro used for keyboard, and possible other features.
+
+The CROS_EC keyboard uses this protocol to receive key scans and produce input
+in U-Boot.
+
+Required properties :
+- compatible : "google,cros-ec-keyb"
+- google,key-rows : Number of key rows
+- google,key-columns : Number of key columns
+
+Optional properties, in addition to those specified by the shared
+matrix-keyboard bindings:
+
+- linux,fn-keymap: a second keymap, same specification as the
+  matrix-keyboard-controller spec but to be used when the KEY_FN modifier
+  key is pressed.
+- google,repeat-delay-ms : delay in milliseconds before repeat starts
+- google,repeat-rate-ms : delay between each subsequent key press
+- google,ghost-filter : enable ghost filtering for this device
+
+Example, taken from daisy:
+
+cros-ec-keyb {
+	compatible = "google,cros-ec-keyb";
+	google,key-rows = <8>;
+	google,key-columns = <13>;
+	google,ghost-filter;
+	google,repeat-delay-ms = <240>;
+	google,repeat-rate-ms = <30>;
+	/*
+		* Keymap entries take the form of 0xRRCCKKKK where
+		* RR=Row CC=Column KKKK=Key Code
+		* The values below are for a US keyboard layout and
+		* are taken from the Linux driver. Note that the
+		* 102ND key is not used for US keyboards.
+		*/
+	linux,keymap = <
+		/* CAPSLCK F1         B          F10     */
+		0x0001003a 0x0002003c 0x00030030 0x00040044
+		/* N       =          R_ALT      ESC     */
+		0x00060031 0x0008000d 0x000a0064 0x01010001
+		/* F4      G          F7         H       */
+		0x0102003e 0x01030022 0x01040041 0x01060023
+		/* '       F9         BKSPACE    L_CTRL  */
+		0x01080028 0x01090043 0x010b000e 0x0200001d
+		/* TAB     F3         T          F6      */
+		0x0201000f 0x0202003d 0x02030014 0x02040040
+		/* ]       Y          102ND      [       */
+		0x0205001b 0x02060015 0x02070056 0x0208001a
+		/* F8      GRAVE      F2         5       */
+		0x02090042 0x03010029 0x0302003c 0x03030006
+		/* F5      6          -          \       */
+		0x0304003f 0x03060007 0x0308000c 0x030b002b
+		/* R_CTRL  A          D          F       */
+		0x04000061 0x0401001e 0x04020020 0x04030021
+		/* S       K          J          ;       */
+		0x0404001f 0x04050025 0x04060024 0x04080027
+		/* L       ENTER      Z          C       */
+		0x04090026 0x040b001c 0x0501002c 0x0502002e
+		/* V       X          ,          M       */
+		0x0503002f 0x0504002d 0x05050033 0x05060032
+		/* L_SHIFT /          .          SPACE   */
+		0x0507002a 0x05080035 0x05090034 0x050B0039
+		/* 1       3          4          2       */
+		0x06010002 0x06020004 0x06030005 0x06040003
+		/* 8       7          0          9       */
+		0x06050009 0x06060008 0x0608000b 0x0609000a
+		/* L_ALT   DOWN       RIGHT      Q       */
+		0x060a0038 0x060b006c 0x060c006a 0x07010010
+		/* E       R          W          I       */
+		0x07020012 0x07030013 0x07040011 0x07050017
+		/* U       R_SHIFT    P          O       */
+		0x07060016 0x07070036 0x07080019 0x07090018
+		/* UP      LEFT    */
+		0x070b0067 0x070c0069>;
+};