platform/chrome: cros_ec: Match implementation with headers

The 'cros_ec' core driver is the common interface for the cros_ec
transport drivers to do the shared operations to register, unregister,
suspend, resume and handle_event. The interface is provided by including
the header 'include/linux/platform_data/cros_ec_proto.h', however, instead
of have the implementation of these functions in cros_ec_proto.c, it is in
'cros_ec.c', which is a different kernel module. Apart from being a bad
practice, this can induce confusions allowing the users of the cros_ec
protocol to call these functions.

The register, unregister, suspend, resume and handle_event functions
*should* only be called by the different transport drivers (i2c, spi, lpc,
etc.), so make this a bit less confusing by moving these functions from
the public in-kernel space to a private include in platform/chrome, and
then, the interface for cros_ec module and for the cros_ec_proto module is
clean.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Benson Leung <bleung@chromium.org>

drivers/platform/chrome/cros_ec.c

@@ -17,6 +17,8 @@
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/suspend.h>
 
+#include "cros_ec.h"
+
 #define CROS_EC_DEV_EC_INDEX 0
 #define CROS_EC_DEV_PD_INDEX 1
 

drivers/platform/chrome/cros_ec.h

@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * ChromeOS Embedded Controller core interface.
+ *
+ * Copyright (C) 2020 Google LLC
+ */
+
+#ifndef __CROS_EC_H
+#define __CROS_EC_H
+
+int cros_ec_register(struct cros_ec_device *ec_dev);
+int cros_ec_unregister(struct cros_ec_device *ec_dev);
+
+int cros_ec_suspend(struct cros_ec_device *ec_dev);
+int cros_ec_resume(struct cros_ec_device *ec_dev);
+
+bool cros_ec_handle_event(struct cros_ec_device *ec_dev);
+
+#endif /* __CROS_EC_H */

drivers/platform/chrome/cros_ec_i2c.c

@@ -14,6 +14,8 @@
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 
+#include "cros_ec.h"
+
 /**
  * Request format for protocol v3
  * byte 0	0xda (EC_COMMAND_PROTOCOL_3)

drivers/platform/chrome/cros_ec_ishtp.c

@@ -14,6 +14,8 @@
 #include <linux/platform_data/cros_ec_proto.h>
 #include <linux/intel-ish-client-if.h>
 
+#include "cros_ec.h"
+
 /*
  * ISH TX/RX ring buffer pool size
  *

drivers/platform/chrome/cros_ec_lpc.c

@@ -23,6 +23,7 @@
 #include <linux/printk.h>
 #include <linux/suspend.h>
 
+#include "cros_ec.h"
 #include "cros_ec_lpc_mec.h"
 
 #define DRV_NAME "cros_ec_lpcs"

drivers/platform/chrome/cros_ec_rpmsg.c

@@ -13,6 +13,8 @@
 #include <linux/rpmsg.h>
 #include <linux/slab.h>
 
+#include "cros_ec.h"
+
 #define EC_MSG_TIMEOUT_MS	200
 #define HOST_COMMAND_MARK	1
 #define HOST_EVENT_MARK		2

drivers/platform/chrome/cros_ec_spi.c

@@ -14,6 +14,8 @@
 #include <linux/spi/spi.h>
 #include <uapi/linux/sched/types.h>
 
+#include "cros_ec.h"
+
 /* The header byte, which follows the preamble */
 #define EC_MSG_HEADER			0xec