kblight: Add keyboard backlight control module

This patch promotes board/nami/keyboard_backlight.c to common
directory.
Board customization is done via board_kblight_init callback.
It currently supports two drivers: direct PWM control and lm3509.

Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>

BUG=b:78360907,b:78141647
BRANCH=none
TEST=On Nami (for lm3509) and Sona (pwm), verify the followings:
1. Alt + brightness up/down works
2. After suspend-resume, brightness is restored
3. Lid close/open
4. After screen is off, keyboard backlight is turned off

Change-Id: I584c06e8702fe7b289999698f277311cfd3400bd
Reviewed-on: https://chromium-review.googlesource.com/1051027
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/include/keyboard_backlight.h b/include/keyboard_backlight.h
new file mode 100644
index 0000000000..2389b3dfe0
--- /dev/null
+++ b/include/keyboard_backlight.h
@@ -0,0 +1,79 @@
+/* Copyright 2018 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef __CROS_EC_KEYBOARD_BACKLIGHT_H
+#define __CROS_EC_KEYBOARD_BACKLIGHT_H
+
+struct kblight_conf {
+	const struct kblight_drv *drv;
+};
+
+struct kblight_drv {
+	/**
+	 * Initialize the keyboard backlight controller
+	 * @return EC_SUCCESS or EC_ERROR_*
+	 */
+	int (*init)(void);
+
+	/**
+	 * Set the brightness
+	 * @param percent
+	 * @return EC_SUCCESS or EC_ERROR_*
+	 */
+	int (*set)(int percent);
+
+	/**
+	 * Get the current brightness
+	 * @return Brightness in percentage
+	 */
+	int (*get)(void);
+
+	/**
+	 * Enable or disable keyboard backlight
+	 * @param enable: 1=Enable, 0=Disable.
+	 * @return EC_SUCCESS or EC_ERROR_*
+	 */
+	int (*enable)(int enable);
+};
+
+/**
+ * Initialize keyboard backlight per board
+ */
+void board_kblight_init(void);
+
+/**
+ * Set keyboard backlight brightness
+ *
+ * @param percent Brightness in percentage
+ * @return EC_SUCCESS or EC_ERROR_*
+ */
+int kblight_set(int percent);
+
+/**
+ * Get keyboard backlight brightness
+ *
+ * @return Brightness in percentage
+ */
+int kblight_get(void);
+
+/**
+ * Enable or disable keyboard backlight
+ *
+ * @param enable: 1=Enable, 0=Disable.
+ * @return EC_SUCCESS or EC_ERROR_*
+ */
+int kblight_enable(int enable);
+
+/**
+ * Register keyboard backlight controller
+ *
+ * @param drv: Driver of keyboard backlight controller
+ * @return EC_SUCCESS or EC_ERROR_*
+ */
+int kblight_register(const struct kblight_drv *drv);
+
+extern const struct kblight_drv kblight_pwm;
+
+#endif /* __CROS_EC_KEYBOARD_BACKLIGHT_H */