main: Initialize I2C pretty early

Some devices (like the keyboard, CBI) need I2C access pretty early.
Until now I2C would get initialized pretty late in a hook, which was far
too late for some stuff.

As a result from this change, CONFIG_I2C_MASTER now implies the i2c_init()
function will be called at board boot. Some chips (cr50, host tests)
needed a stub i2c_init in order to compile cleanly.

BUG=b/138384267
TEST=EFS doesn't happen significantly later than it used to
TEST=Recovery keys now work with I2C keyboard on jacuzzi
TEST=make buildall
TEST=Sanity check i2c behavior (booting, "i2scan", "battery") on a variety
of ECs:
        * ampton (ite EC, x86 AP)
        * bobba (npcx EC, x86 AP)
        * jacuzzi (stm32f0 EC, ARM AP)
        * cheza (npcx EC, ARM AP)
BRANCH=master

Change-Id: Ifa830e8e509ff16b36b4dcc86617869b1cb86ac3
Signed-off-by: Alexandru M Stan <amstan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1772490
Reviewed-by: Jett Rink <jettrink@chromium.org>
Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/include/i2c.h b/include/i2c.h
index dd237e5354..0d68b5bc90 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -447,9 +447,15 @@ enum ec_status i2c_get_protocol_info(struct host_cmd_handler_args *args);
 void i2c_data_received(int port, uint8_t *buf, int len);
 int i2c_set_response(int port, uint8_t *buf, int len);
 
+/*
+ * Initialize i2c master controller. Automatically called at board boot
+ * if CONFIG_I2C_MASTER is defined.
+ */
+void i2c_init(void);
+
 /**
  * Initialize i2c master ports. This function can be called for cases where i2c
- * ports are not initialized by default via a hook call.
+ * ports are not initialized by default from main.c.
  */
 void i2cm_init(void);