Make i8042 independent of host <--> KBC bus.

This CL attempts to abstract underlying bus from i8042 code. Nearly
all i8042 logic is isolated already. This patch is intended to allow
us to use i8042 logic for processing keys and commands on boards which
do not necessarily use LPC as the host <--> KBC bus interface.

This CL does the following:
- Define KBC bus <--> host (kbc_host_bus) on a per-board basis in
  board.c.

- Add generic wrappers in place of lpc_keyboard_* in i8042 code.

- Define the behavior of generic wrappers in EC-specific keyboard
  sources. If board.c specifies LPC, then send via LPC.

TODO: This needs to be tested on real hardware...

Signed-off-by: David Hendricks <dhendrix@chromium.org>

BUG=None
TEST=Locally compiled for Link, BDS and Discovery.

Change-Id: I9cabd514bd44fd6b508c26994eccc3011eedbc0f

2 files changed, 3 insertions, 1 deletions

diff --git a/board/discovery/board.c b/board/discovery/board.c
index e516dc4278..4b4cd676ca 100644
--- a/board/discovery/board.c
+++ b/board/discovery/board.c
@@ -5,7 +5,6 @@
 /* STM32L Discovery board-specific configuration */
 
 #include "board.h"
-#include "common.h"
 #include "gpio.h"
 #include "registers.h"
 #include "util.h"
diff --git a/board/discovery/board.h b/board/discovery/board.h
index 72fca4690a..69cc237d62 100644
--- a/board/discovery/board.h
+++ b/board/discovery/board.h
@@ -16,6 +16,9 @@
 
 #define USB_CHARGE_PORT_COUNT 0
 
+/* Host connects to keyboard controller module via I2C */
+#define HOST_KB_BUS_I2C
+
 /* GPIO signal list */
 enum gpio_signal {
 	/* Inputs with interrupt handlers are first for efficiency */