kblight: Remove dependency on PWM

Keyboard backlight can be controlled either by PWM or an external
controller. This patch decouples keyboard backlight common code and
PWM based backlight control.

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

BUG=none
BRANCH=Nami
TEST=Verify keyboard backlight can be adjusted on Ekko.

Change-Id: I332b01a2a2b15bd37ce385b6c30591c90f078dfc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1549476
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Commit-Queue: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
(cherry picked from commit e879713cee3212b4afffb3f0dd3c4dfbf8237c4a)
Reviewed-on: https://chromium-review.googlesource.com/1549606
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

5 files changed, 19 insertions, 6 deletions

diff --git a/common/acpi.c b/common/acpi.c
index e33ac17bb0..e681fd25a6 100644
--- a/common/acpi.c
+++ b/common/acpi.c
@@ -195,7 +195,7 @@ int acpi_ap_to_ec(int is_cmd, uint8_t value, uint8_t *resultptr)
 		case EC_ACPI_MEM_TEST_COMPLIMENT:
 			result = 0xff - acpi_mem_test;
 			break;
-#ifdef CONFIG_PWM_KBLIGHT
+#ifdef CONFIG_KEYBOARD_BACKLIGHT
 		case EC_ACPI_MEM_KEYBOARD_BACKLIGHT:
 			result = kblight_get();
 			break;
@@ -301,7 +301,7 @@ int acpi_ap_to_ec(int is_cmd, uint8_t value, uint8_t *resultptr)
 			battery_memmap_set_index(data);
 			break;
 #endif
-#ifdef CONFIG_PWM_KBLIGHT
+#ifdef CONFIG_KEYBOARD_BACKLIGHT
 		case EC_ACPI_MEM_KEYBOARD_BACKLIGHT:
 			/*
 			 * Debug output with CR not newline, because the host
diff --git a/common/build.mk b/common/build.mk
index d9418f7a31..7d5cd9dad0 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -98,7 +98,7 @@ common-$(CONFIG_POWER_BUTTON_X86)+=power_button_x86.o
 common-$(CONFIG_PSTORE)+=pstore_commands.o
 common-$(CONFIG_PWM)+=pwm.o
 common-$(CONFIG_PWM_KBLIGHT)+=pwm_kblight.o
-common-$(CONFIG_PWM_KBLIGHT)+=keyboard_backlight.o
+common-$(CONFIG_KEYBOARD_BACKLIGHT)+=keyboard_backlight.o
 common-$(CONFIG_RMA_AUTH)+=rma_auth.o
 common-$(CONFIG_RSA)+=rsa.o
 common-$(CONFIG_ROLLBACK)+=rollback.o
diff --git a/common/ec_features.c b/common/ec_features.c
index fb45789a63..4e17764127 100644
--- a/common/ec_features.c
+++ b/common/ec_features.c
@@ -22,7 +22,7 @@ uint32_t get_feature_flags0(void)
 #ifdef CONFIG_FANS
 		| EC_FEATURE_MASK_0(EC_FEATURE_PWM_FAN)
 #endif
-#ifdef CONFIG_PWM_KBLIGHT
+#ifdef CONFIG_KEYBOARD_BACKLIGHT
 		| EC_FEATURE_MASK_0(EC_FEATURE_PWM_KEYB)
 #endif
 #ifdef HAS_TASK_LIGHTBAR
diff --git a/common/keyboard_backlight.c b/common/keyboard_backlight.c
index 8fdc5dc0cf..7962fea99c 100644
--- a/common/keyboard_backlight.c
+++ b/common/keyboard_backlight.c
@@ -74,7 +74,9 @@ int kblight_register(const struct kblight_drv *drv)
 static void keyboard_backlight_init(void)
 {
 	/* Uses PWM by default. Can be customized by board_kblight_init */
+#ifdef CONFIG_PWM_KBLIGHT
 	kblight_register(&kblight_pwm);
+#endif
 	board_kblight_init();
 	if (kblight_init())
 		CPRINTS("kblight init failed");
diff --git a/include/config.h b/include/config.h
index 53d983f12b..5a62cb5728 100644
--- a/include/config.h
+++ b/include/config.h
@@ -2693,10 +2693,17 @@
 #undef CONFIG_PWM_DISPLIGHT
 
 /*
+ * Support keyboard backlight control
+ *
+ * You need to define board_kblight_init unless CONFIG_PWM_KBLIGHT is used.
+ * For example, lm3509 can be registered as a driver in board_kblight_init.
+ */
+#undef CONFIG_KEYBOARD_BACKLIGHT
+
+/*
  * Support PWM output to keyboard backlight
  *
- * Optionally, lm3509 can be used as a keyboard backlight controller.
- * TODO: Create CONFIG_KEYBOARD_BACKLIGHT to allow lm3509 is used without PWM.
+ * This implies CONFIG_KEYBOARD_BACKLIGHT.
  */
 #undef CONFIG_PWM_KBLIGHT
 
@@ -4391,4 +4398,8 @@
 #define CONFIG_SLEEP_TIMEOUT_MS 10000
 #endif
 
+#ifdef CONFIG_PWM_KBLIGHT
+#define CONFIG_KEYBOARD_BACKLIGHT
+#endif
+
 #endif  /* __CROS_EC_CONFIG_H */