zephyr: tests: Test Host command EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT

Test the above host command in `common/keyboard_backlight.c`

BRANCH=None
BUG=b:246577858
TEST=./twister

Signed-off-by: Tristan Honscheid <honscheid@google.com>
Change-Id: I4f5c6074bddd4ec78919794cc02a98ed2faa4638
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3893396
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
Reviewed-by: Yuval Peress <peress@google.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/zephyr/test/drivers/keyboard_scan/CMakeLists.txt b/zephyr/test/drivers/keyboard_scan/CMakeLists.txt
index 0def2a5ff9..07040187f2 100644
--- a/zephyr/test/drivers/keyboard_scan/CMakeLists.txt
+++ b/zephyr/test/drivers/keyboard_scan/CMakeLists.txt
@@ -3,6 +3,7 @@
 # found in the LICENSE file.
 
 target_sources(app PRIVATE
+  src/keyboard_backlight.c
   src/keyboard_scan.c
   src/keyboard_test_utils.c
   src/mkbp_event.c
diff --git a/zephyr/test/drivers/keyboard_scan/src/keyboard_backlight.c b/zephyr/test/drivers/keyboard_scan/src/keyboard_backlight.c
new file mode 100644
index 0000000000..00cf99b7ac
--- /dev/null
+++ b/zephyr/test/drivers/keyboard_scan/src/keyboard_backlight.c
@@ -0,0 +1,60 @@
+/* Copyright 2022 The ChromiumOS Authors
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <stdint.h>
+#include <zephyr/ztest.h>
+#include <zephyr/kernel.h>
+#include <zephyr/ztest_assert.h>
+
+#include "host_command.h"
+#include "keyboard_backlight.h"
+#include "test/drivers/test_state.h"
+
+/**
+ * @brief Send host command to set the backlight percentage
+ *
+ * @param percent Backlight intensity, from 0 to 100 (inclusive).
+ * @return uint16_t Host command return code
+ */
+static uint16_t set_backlight_percent_helper(uint8_t percent)
+{
+	struct ec_params_pwm_set_keyboard_backlight params = {
+		.percent = percent
+	};
+	struct host_cmd_handler_args args = BUILD_HOST_COMMAND_PARAMS(
+		EC_CMD_PWM_SET_KEYBOARD_BACKLIGHT, 0, params);
+
+	return host_command_process(&args);
+}
+
+ZTEST(keyboard_backlight, host_command_set_backlight__normal)
+{
+	/* Set the backlight intensity level to this and verify */
+	uint8_t expected_percentage = 50;
+
+	zassert_ok(set_backlight_percent_helper(expected_percentage), NULL);
+	zassert_equal(expected_percentage, kblight_get(), NULL);
+}
+
+ZTEST(keyboard_backlight, host_command_set_backlight__out_of_range)
+{
+	/* Too high */
+	uint8_t expected_percentage = 101;
+
+	zassert_equal(EC_RES_ERROR,
+		      set_backlight_percent_helper(expected_percentage), NULL);
+}
+
+static void reset(void *data)
+{
+	ARG_UNUSED(data);
+
+	/* Reset the backlight to off and 0% brightness */
+	kblight_set(0);
+	kblight_enable(0);
+}
+
+ZTEST_SUITE(keyboard_backlight, drivers_predicate_post_main, NULL, reset, reset,
+	    NULL);