platform/chrome: cros_ec_proto: add Kunit tests for cros_ec_query_all()

cros_ec_query_all() sends multiple host commands to EC for querying
supported protocols and settings.

Add required mock for interacting with cros_ec_query_all() and Kunit
tests.

Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220609084957.3684698-3-tzungbi@kernel.org

drivers/platform/chrome/Kconfig

@@ -268,11 +268,17 @@ config CHROMEOS_PRIVACY_SCREEN
 source "drivers/platform/chrome/wilco_ec/Kconfig"
 
 # Kunit test cases
+config CROS_KUNIT
+	tristate
+	help
+	  ChromeOS Kunit.
+
 config CROS_EC_PROTO_KUNIT_TEST
 	tristate "Kunit tests for ChromeOS EC protocol" if !KUNIT_ALL_TESTS
 	depends on KUNIT && CROS_EC
 	default KUNIT_ALL_TESTS
 	select CROS_EC_PROTO
+	select CROS_KUNIT
 	help
 	  Kunit tests for the ChromeOS Embedded Controller protocol.
 

drivers/platform/chrome/Makefile

@@ -32,4 +32,5 @@ obj-$(CONFIG_CROS_USBPD_NOTIFY)		+= cros_usbpd_notify.o
 obj-$(CONFIG_WILCO_EC)			+= wilco_ec/
 
 # Kunit test cases
+obj-$(CONFIG_CROS_KUNIT)		+= cros_kunit_util.o
 obj-$(CONFIG_CROS_EC_PROTO_KUNIT_TEST)	+= cros_ec_proto_test.o

drivers/platform/chrome/cros_kunit_util.c

@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CrOS Kunit tests utilities.
+ */
+
+#include <kunit/test.h>
+
+#include <linux/list.h>
+#include <linux/minmax.h>
+#include <linux/platform_data/cros_ec_commands.h>
+#include <linux/platform_data/cros_ec_proto.h>
+
+#include "cros_ec.h"
+#include "cros_kunit_util.h"
+
+int cros_kunit_ec_xfer_mock_default_ret;
+EXPORT_SYMBOL_GPL(cros_kunit_ec_xfer_mock_default_ret);
+
+static struct list_head cros_kunit_ec_xfer_mock_in;
+static struct list_head cros_kunit_ec_xfer_mock_out;
+
+int cros_kunit_ec_xfer_mock(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
+{
+	struct ec_xfer_mock *mock;
+
+	mock = list_first_entry_or_null(&cros_kunit_ec_xfer_mock_in, struct ec_xfer_mock, list);
+	if (!mock)
+		return cros_kunit_ec_xfer_mock_default_ret;
+
+	list_del(&mock->list);
+
+	memcpy(&mock->msg, msg, sizeof(*msg));
+	if (msg->outsize) {
+		mock->i_data = kunit_kzalloc(mock->test, msg->outsize, GFP_KERNEL);
+		if (mock->i_data)
+			memcpy(mock->i_data, msg->data, msg->outsize);
+	}
+
+	msg->result = mock->result;
+	if (msg->insize)
+		memcpy(msg->data, mock->o_data, min(msg->insize, mock->o_data_len));
+
+	list_add_tail(&mock->list, &cros_kunit_ec_xfer_mock_out);
+
+	return mock->ret;
+}
+EXPORT_SYMBOL_GPL(cros_kunit_ec_xfer_mock);
+
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_add(struct kunit *test, size_t size)
+{
+	return cros_kunit_ec_xfer_mock_addx(test, size, EC_RES_SUCCESS, size);
+}
+EXPORT_SYMBOL_GPL(cros_kunit_ec_xfer_mock_add);
+
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_addx(struct kunit *test,
+						  int ret, int result, size_t size)
+{
+	struct ec_xfer_mock *mock;
+
+	mock = kunit_kzalloc(test, sizeof(*mock), GFP_KERNEL);
+	if (!mock)
+		return NULL;
+
+	list_add_tail(&mock->list, &cros_kunit_ec_xfer_mock_in);
+	mock->test = test;
+
+	mock->ret = ret;
+	mock->result = result;
+	mock->o_data = kunit_kzalloc(test, size, GFP_KERNEL);
+	if (!mock->o_data)
+		return NULL;
+	mock->o_data_len = size;
+
+	return mock;
+}
+EXPORT_SYMBOL_GPL(cros_kunit_ec_xfer_mock_addx);
+
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_next(void)
+{
+	struct ec_xfer_mock *mock;
+
+	mock = list_first_entry_or_null(&cros_kunit_ec_xfer_mock_out, struct ec_xfer_mock, list);
+	if (mock)
+		list_del(&mock->list);
+
+	return mock;
+}
+EXPORT_SYMBOL_GPL(cros_kunit_ec_xfer_mock_next);
+
+void cros_kunit_mock_reset(void)
+{
+	cros_kunit_ec_xfer_mock_default_ret = 0;
+	INIT_LIST_HEAD(&cros_kunit_ec_xfer_mock_in);
+	INIT_LIST_HEAD(&cros_kunit_ec_xfer_mock_out);
+}
+EXPORT_SYMBOL_GPL(cros_kunit_mock_reset);
+
+MODULE_LICENSE("GPL");

drivers/platform/chrome/cros_kunit_util.h

@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * CrOS Kunit tests utilities.
+ */
+
+#ifndef _CROS_KUNIT_UTIL_H_
+#define _CROS_KUNIT_UTIL_H_
+
+#include <linux/platform_data/cros_ec_proto.h>
+
+struct ec_xfer_mock {
+	struct list_head list;
+	struct kunit *test;
+
+	/* input */
+	struct cros_ec_command msg;
+	void *i_data;
+
+	/* output */
+	int ret;
+	int result;
+	void *o_data;
+	u32 o_data_len;
+};
+
+extern int cros_kunit_ec_xfer_mock_default_ret;
+
+int cros_kunit_ec_xfer_mock(struct cros_ec_device *ec_dev, struct cros_ec_command *msg);
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_add(struct kunit *test, size_t size);
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_addx(struct kunit *test,
+						  int ret, int result, size_t size);
+struct ec_xfer_mock *cros_kunit_ec_xfer_mock_next(void);
+
+void cros_kunit_mock_reset(void);
+
+#endif