Move x86 backlight-enable passthru code to its own module

This code is not LM4-specific, it's x86-specific.  So it doesn't
belong in chip/lm4.  Put it in its own module rather than leaving it
in switch.c, since some x86 systems may need the power button state
machine but not the backlight-enable passthru.

BUG=chrome-os-partner:18343
BRANCH=none
TEST=Quickly run a magnet over the lid switch; the backlight goes off and then
     back on.

Change-Id: I72f7139b73f91539dcfbe6b5cb6d56587ab66fde
Signed-off-by: Randall Spangler <rspangler@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/61595
Reviewed-by: Bill Richardson <wfrichar@chromium.org>

14 files changed, 92 insertions, 52 deletions

diff --git a/board/falco/board.c b/board/falco/board.c
index f394244d63..b98d03f7b2 100644
--- a/board/falco/board.c
+++ b/board/falco/board.c
@@ -5,7 +5,7 @@
 /* EC for Falco board configuration */
 
 #include "adc.h"
-#include "board.h"
+#include "backlight.h"
 #include "chip_temp_sensor.h"
 #include "chipset_haswell.h"
 #include "chipset_x86_common.h"
@@ -37,7 +37,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"AC_PRESENT",           LM4_GPIO_H, (1<<3), GPIO_INT_BOTH,
 	 extpower_interrupt},
 	{"PCH_BKLTEN",           LM4_GPIO_M, (1<<3), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 backlight_interrupt},
 	{"PCH_SLP_S0_L",         LM4_GPIO_G, (1<<6), GPIO_INT_BOTH,
 	 x86_interrupt},
 	{"PCH_SLP_S3_L",         LM4_GPIO_G, (1<<7), GPIO_INT_BOTH,
diff --git a/board/falco/board.h b/board/falco/board.h
index a2fbc8a47d..5a20099288 100644
--- a/board/falco/board.h
+++ b/board/falco/board.h
@@ -16,6 +16,7 @@
 
 /* Optional features */
 #define CONFIG_SMART_BATTERY
+#define CONFIG_BACKLIGHT_X86
 #define CONFIG_BATTERY_FALCO
 #define CONFIG_EXTPOWER_FALCO
 #define CONFIG_BOARD_VERSION
diff --git a/board/link/board.c b/board/link/board.c
index 301140d9b9..62c7332d78 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -5,7 +5,7 @@
 /* EC for Link board configuration */
 
 #include "adc.h"
-#include "board.h"
+#include "backlight.h"
 #include "chip_temp_sensor.h"
 #include "chipset_ivybridge.h"
 #include "chipset_x86_common.h"
@@ -41,7 +41,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"BOARD_VERSION2",       LM4_GPIO_L, (1<<6), 0, NULL},
 	{"BOARD_VERSION3",       LM4_GPIO_L, (1<<7), 0, NULL},
 	{"PCH_BKLTEN",           LM4_GPIO_J, (1<<3), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 backlight_interrupt},
 	{"PCH_SLP_A_L",          LM4_GPIO_G, (1<<5), GPIO_INT_BOTH,
 	 x86_interrupt},
 	{"PCH_SLP_ME_CSW_DEV_L", LM4_GPIO_G, (1<<4), GPIO_INT_BOTH,
diff --git a/board/link/board.h b/board/link/board.h
index 711c36c2c3..38e7130ba7 100644
--- a/board/link/board.h
+++ b/board/link/board.h
@@ -16,6 +16,7 @@
 
 /* Optional features */
 #define CONFIG_SMART_BATTERY
+#define CONFIG_BACKLIGHT_X86
 #define CONFIG_BATTERY_LINK
 #define CONFIG_BOARD_VERSION
 #define CONFIG_CHARGER
diff --git a/board/peppy/board.c b/board/peppy/board.c
index 5f1422e98c..293747c43b 100644
--- a/board/peppy/board.c
+++ b/board/peppy/board.c
@@ -5,7 +5,7 @@
 /* EC for Peppy board configuration */
 
 #include "adc.h"
-#include "board.h"
+#include "backlight.h"
 #include "chip_temp_sensor.h"
 #include "chipset_haswell.h"
 #include "chipset_x86_common.h"
@@ -37,7 +37,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"AC_PRESENT",           LM4_GPIO_H, (1<<3), GPIO_INT_BOTH,
 	 extpower_interrupt},
 	{"PCH_BKLTEN",           LM4_GPIO_M, (1<<3), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 backlight_interrupt},
 	{"PCH_SLP_S0_L",         LM4_GPIO_G, (1<<6), GPIO_INT_BOTH,
 	 x86_interrupt},
 	{"PCH_SLP_S3_L",         LM4_GPIO_G, (1<<7), GPIO_INT_BOTH,
diff --git a/board/peppy/board.h b/board/peppy/board.h
index 102c2fffa9..70ad78c48d 100644
--- a/board/peppy/board.h
+++ b/board/peppy/board.h
@@ -16,6 +16,7 @@
 
 /* Optional features */
 #define CONFIG_SMART_BATTERY
+#define CONFIG_BACKLIGHT_X86
 #define CONFIG_BATTERY_PEPPY
 #define CONFIG_BOARD_VERSION
 #define CONFIG_CHARGER
diff --git a/board/slippy/board.c b/board/slippy/board.c
index bf06a80b54..da361174c2 100644
--- a/board/slippy/board.c
+++ b/board/slippy/board.c
@@ -5,7 +5,7 @@
 /* EC for Slippy board configuration */
 
 #include "adc.h"
-#include "board.h"
+#include "backlight.h"
 #include "chip_temp_sensor.h"
 #include "chipset_haswell.h"
 #include "chipset_x86_common.h"
@@ -37,7 +37,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"AC_PRESENT",           LM4_GPIO_H, (1<<3), GPIO_INT_BOTH,
 	 extpower_interrupt},
 	{"PCH_BKLTEN",           LM4_GPIO_M, (1<<3), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 backlight_interrupt},
 	{"PCH_SLP_S0_L",         LM4_GPIO_G, (1<<6), GPIO_INT_BOTH,
 	 x86_interrupt},
 	{"PCH_SLP_S3_L",         LM4_GPIO_G, (1<<7), GPIO_INT_BOTH,
diff --git a/board/slippy/board.h b/board/slippy/board.h
index e322d1abd5..d41db4781b 100644
--- a/board/slippy/board.h
+++ b/board/slippy/board.h
@@ -16,6 +16,7 @@
 
 /* Optional features */
 #define CONFIG_SMART_BATTERY
+#define CONFIG_BACKLIGHT_X86
 #define CONFIG_BATTERY_SLIPPY
 #define CONFIG_BOARD_VERSION
 #define CONFIG_CHARGER
diff --git a/board/wolf/board.c b/board/wolf/board.c
index 8c05c72ae8..c1afbb1cbd 100644
--- a/board/wolf/board.c
+++ b/board/wolf/board.c
@@ -5,7 +5,7 @@
 /* EC for Wolf board configuration */
 
 #include "adc.h"
-#include "board.h"
+#include "backlight.h"
 #include "chip_temp_sensor.h"
 #include "chipset_haswell.h"
 #include "chipset_x86_common.h"
@@ -36,7 +36,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"AC_PRESENT",           LM4_GPIO_H, (1<<3), GPIO_INT_BOTH,
 	 extpower_interrupt},
 	{"PCH_BKLTEN",           LM4_GPIO_M, (1<<3), GPIO_INT_BOTH,
-	 switch_interrupt},
+	 backlight_interrupt},
 	{"PCH_SLP_S0_L",         LM4_GPIO_G, (1<<6), GPIO_INT_BOTH,
 	 x86_interrupt},
 	{"PCH_SLP_S3_L",         LM4_GPIO_G, (1<<7), GPIO_INT_BOTH,
diff --git a/board/wolf/board.h b/board/wolf/board.h
index 06598cfe66..2e8a41b884 100644
--- a/board/wolf/board.h
+++ b/board/wolf/board.h
@@ -15,6 +15,7 @@
 #define CONFIG_TASK_PROFILING
 
 /* Optional features */
+#define CONFIG_BACKLIGHT_X86
 #ifdef HAS_TASK_CHIPSET
 #define CONFIG_CHIPSET_HASWELL
 #endif
diff --git a/chip/lm4/switch.c b/chip/lm4/switch.c
index a70a163dbb..9d11aa2d9e 100644
--- a/chip/lm4/switch.c
+++ b/chip/lm4/switch.c
@@ -146,15 +146,6 @@ static void set_pwrbtn_to_pch(int high)
 	gpio_set_level(GPIO_PCH_PWRBTN_L, high);
 }
 
-static void update_backlight(void)
-{
-	/* Only enable the backlight if the lid is open */
-	if (gpio_get_level(GPIO_PCH_BKLTEN) && lid_is_open())
-		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 1);
-	else
-		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 0);
-}
-
 /**
  * Handle debounced power button down.
  */
@@ -402,14 +393,12 @@ static void switch_init(void)
 		*memmap_switches |= EC_SWITCH_LID_OPEN;
 
 	update_other_switches();
-	update_backlight();
 	set_initial_pwrbtn_state();
 
 	/* Switch data is now present */
 	*host_get_memmap(EC_MEMMAP_SWITCHES_VERSION) = 1;
 
 	/* Enable interrupts, now that we've initialized */
-	gpio_enable_interrupt(GPIO_PCH_BKLTEN);
 	gpio_enable_interrupt(GPIO_POWER_BUTTON_L);
 	gpio_enable_interrupt(GPIO_RECOVERY_L);
 #ifdef CONFIG_WP_ACTIVE_HIGH
@@ -425,8 +414,6 @@ DECLARE_HOOK(HOOK_INIT, switch_init, HOOK_PRIO_DEFAULT);
  */
 static void switch_lid_change(void)
 {
-	update_backlight();
-
 	if (lid_is_open()) {
 		*memmap_switches |= EC_SWITCH_LID_OPEN;
 
@@ -484,26 +471,7 @@ DECLARE_HOOK(HOOK_POWER_BUTTON_CHANGE, power_button_changed, HOOK_PRIO_DEFAULT);
 
 void switch_interrupt(enum gpio_signal signal)
 {
-	/* Reset debounce time for the changed signal */
-	switch (signal) {
-	case GPIO_PCH_BKLTEN:
-		update_backlight();
-		break;
-	default:
-		/*
-		 * Change in non-debounced switches; we'll update their state
-		 * automatically the next time through the task loop.
-		 */
-		break;
-	}
-
-	/*
-	 * We don't have a way to tell the task to wake up at the end of the
-	 * debounce interval; wake it up now so it can go back to sleep for the
-	 * remainder of the interval.  The alternative would be to have the
-	 * task wake up _every_ debounce_us on its own; that's less desirable
-	 * when the EC should be sleeping.
-	 */
+	/* Wake task to handle change in non-debounced switches */
 	task_wake(TASK_ID_SWITCH);
 }
 
@@ -535,15 +503,6 @@ DECLARE_CONSOLE_COMMAND(mmapinfo, command_mmapinfo,
 /*****************************************************************************/
 /* Host commands */
 
-static int switch_command_enable_backlight(struct host_cmd_handler_args *args)
-{
-	const struct ec_params_switch_enable_backlight *p = args->params;
-	gpio_set_level(GPIO_ENABLE_BACKLIGHT, p->enabled);
-	return EC_RES_SUCCESS;
-}
-DECLARE_HOST_COMMAND(EC_CMD_SWITCH_ENABLE_BKLIGHT,
-		     switch_command_enable_backlight, 0);
-
 static int switch_command_enable_wireless(struct host_cmd_handler_args *args)
 {
 	const struct ec_params_switch_enable_wireless *p = args->params;
diff --git a/common/backlight_x86.c b/common/backlight_x86.c
new file mode 100644
index 0000000000..83e9aeab04
--- /dev/null
+++ b/common/backlight_x86.c
@@ -0,0 +1,55 @@
+/* Copyright (c) 2013 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.
+ */
+
+/* Backlight passthru for x86 platforms */
+
+#include "common.h"
+#include "gpio.h"
+#include "hooks.h"
+#include "host_command.h"
+#include "lid_switch.h"
+
+/**
+ * Update backlight state.
+ */
+static void update_backlight(void)
+{
+	/* Only enable the backlight if the lid is open */
+	if (gpio_get_level(GPIO_PCH_BKLTEN) && lid_is_open())
+		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 1);
+	else
+		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 0);
+}
+DECLARE_HOOK(HOOK_LID_CHANGE, update_backlight, HOOK_PRIO_DEFAULT);
+
+/**
+ * Initialize backlight module.
+ */
+static void backlight_init(void)
+{
+	update_backlight();
+
+	gpio_enable_interrupt(GPIO_PCH_BKLTEN);
+}
+DECLARE_HOOK(HOOK_INIT, backlight_init, HOOK_PRIO_DEFAULT);
+
+void backlight_interrupt(enum gpio_signal signal)
+{
+	update_backlight();
+}
+
+/**
+ * Host command to toggle backlight.
+ */
+static int switch_command_enable_backlight(struct host_cmd_handler_args *args)
+{
+	const struct ec_params_switch_enable_backlight *p = args->params;
+	gpio_set_level(GPIO_ENABLE_BACKLIGHT, p->enabled);
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_SWITCH_ENABLE_BKLIGHT,
+		     switch_command_enable_backlight, 0);
+
+
diff --git a/common/build.mk b/common/build.mk
index 9968afa041..a9391d3f68 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -9,6 +9,7 @@
 common-y=main.o util.o console_output.o uart_buffering.o
 common-y+=memory_commands.o shared_mem.o system_common.o hooks.o
 common-y+=gpio_common.o version.o printf.o queue.o
+common-$(CONFIG_BACKLIGHT_X86)+=backlight_x86.o
 common-$(CONFIG_BATTERY_BQ20Z453)+=battery_bq20z453.o
 common-$(CONFIG_BATTERY_LINK)+=battery_link.o
 common-$(CONFIG_BATTERY_SLIPPY)+=battery_slippy.o
diff --git a/include/backlight.h b/include/backlight.h
new file mode 100644
index 0000000000..dd4e06e991
--- /dev/null
+++ b/include/backlight.h
@@ -0,0 +1,20 @@
+/* Copyright (c) 2013 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.
+ */
+
+/* Backlight API for Chrome EC */
+
+#ifndef __CROS_EC_BACKLIGHT_H
+#define __CROS_EC_BACKLIGHT_H
+
+#include "common.h"
+
+/**
+ * Interrupt handler for backlight.
+ *
+ * @param signal	Signal which triggered the interrupt.
+ */
+void backlight_interrupt(enum gpio_signal signal);
+
+#endif  /* __CROS_EC_BACKLIGHT_H */