Disable screen and keyboard backlights when lid is closed.

Signed-off-by: Randall Spangler <rspangler@chromium.org>

BUG=chrome-os-partner:7832
TEST=manual

1. Power on system
2. From ec console: kblight 100
3. Use a magnet next to the left shift key to trigger the lid switch.  Screen and keyboard should go dark.
4. Remove the magnet and they should light up again.

Change-Id: I298ea94930976153d8dcd102316b010ee28cd747

5 files changed, 49 insertions, 20 deletions

diff --git a/board/link/board.c b/board/link/board.c
index 0b69b35d5f..2cb8fe41d0 100644
--- a/board/link/board.c
+++ b/board/link/board.c
@@ -33,7 +33,7 @@ const struct gpio_info gpio_list[GPIO_COUNT] = {
 	{"THERMAL_DATA_READYn", LM4_GPIO_B, (1<<4), 0, NULL},
 	{"AC_PRESENT",          LM4_GPIO_H, (1<<3), 0, NULL},
 	{"PCH_BKLTEN",          LM4_GPIO_J, (1<<3), GPIO_INT_BOTH,
-	 x86_power_interrupt},
+	 power_button_interrupt},
 	{"PCH_SLP_An",          LM4_GPIO_G, (1<<5), GPIO_INT_BOTH,
 	 x86_power_interrupt},
 	{"PCH_SLP_ME_CSW_DEVn", LM4_GPIO_G, (1<<4), GPIO_INT_BOTH,
diff --git a/chip/lm4/power_button.c b/chip/lm4/power_button.c
index 00bf2b8487..d4752f8311 100644
--- a/chip/lm4/power_button.c
+++ b/chip/lm4/power_button.c
@@ -14,6 +14,7 @@
 #include "lpc.h"
 #include "lpc_commands.h"
 #include "power_button.h"
+#include "pwm.h"
 #include "system.h"
 #include "task.h"
 #include "timer.h"
@@ -67,7 +68,7 @@ static uint64_t tdebounce_lid;
 static uint64_t tdebounce_pwr;
 
 static uint8_t *memmap_switches;
-
+static int debounced_lid_open;
 
 /* Update status of non-debounced switches */
 static void update_other_switches(void)
@@ -110,6 +111,19 @@ static int get_power_button_pressed(void)
 }
 
 
+static void update_backlight(void)
+{
+	/* Only enable the backlight if the lid is open */
+	if (gpio_get_level(GPIO_PCH_BKLTEN) && debounced_lid_open)
+		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 1);
+	else
+		gpio_set_level(GPIO_ENABLE_BACKLIGHT, 0);
+
+	/* Same with keyboard backlight */
+	pwm_enable_keyboard_backlight(debounced_lid_open);
+}
+
+
 /* Power button state machine.  Passed current time from usec counter. */
 static void state_machine(uint64_t tnow)
 {
@@ -203,6 +217,7 @@ static void lid_switch_open(uint64_t tnow)
 {
 	uart_printf("[%T PB lid open]\n");
 
+	debounced_lid_open = 1;
 	*memmap_switches |= EC_LPC_SWITCH_LID_OPEN;
 
 	lpc_set_host_events(EC_LPC_HOST_EVENT_MASK(
@@ -224,6 +239,7 @@ static void lid_switch_close(uint64_t tnow)
 {
 	uart_printf("[%T PB lid close]\n");
 
+	debounced_lid_open = 0;
 	*memmap_switches &= ~EC_LPC_SWITCH_LID_OPEN;
 
 	lpc_set_host_events(EC_LPC_HOST_EVENT_MASK(
@@ -234,12 +250,12 @@ static void lid_switch_close(uint64_t tnow)
 /* Handle debounced lid switch changing state */
 static void lid_switch_changed(uint64_t tnow)
 {
-	int v = gpio_get_level(GPIO_LID_SWITCHn);
-
-	if (v)
+	if (gpio_get_level(GPIO_LID_SWITCHn))
 		lid_switch_open(tnow);
 	else
 		lid_switch_close(tnow);
+
+	update_backlight();
 }
 
 
@@ -253,6 +269,9 @@ void power_button_interrupt(enum gpio_signal signal)
 	case GPIO_POWER_BUTTONn:
 		tdebounce_pwr = get_time().val + PWRBTN_DEBOUNCE_US;
 		break;
+	case GPIO_PCH_BKLTEN:
+		update_backlight();
+		break;
 	default:
 		/* Non-debounced switches; we'll update their state
 		 * automatically the next time through the task loop. */
@@ -273,9 +292,12 @@ int power_button_init(void)
 	/* Set up memory-mapped switch positions */
 	memmap_switches = lpc_get_memmap_range() + EC_LPC_MEMMAP_SWITCHES;
 	*memmap_switches = 0;
-	if (gpio_get_level(GPIO_LID_SWITCHn) != 0)
+	if (gpio_get_level(GPIO_LID_SWITCHn) != 0) {
+		debounced_lid_open = 1;
 		*memmap_switches |= EC_LPC_SWITCH_LID_OPEN;
+	}
 	update_other_switches();
+	update_backlight();
 
 	if (system_get_reset_cause() == SYSTEM_RESET_RESET_PIN) {
 		/* Reset triggered by keyboard-controlled reset, so override
diff --git a/chip/lm4/pwm.c b/chip/lm4/pwm.c
index 7fa935dbee..7fc95f0124 100644
--- a/chip/lm4/pwm.c
+++ b/chip/lm4/pwm.c
@@ -86,6 +86,17 @@ int pwm_set_fan_target_rpm(int rpm)
 }
 
 
+int pwm_enable_keyboard_backlight(int enable)
+{
+	if (enable)
+		LM4_FAN_FANCTL |= (1 << FAN_CH_KBLIGHT);
+	else
+		LM4_FAN_FANCTL &= ~(1 << FAN_CH_KBLIGHT);
+
+	return EC_SUCCESS;
+}
+
+
 int pwm_get_keyboard_backlight(void)
 {
 	return ((LM4_FAN_FANCMD(FAN_CH_KBLIGHT) >> 16) * 100 +
diff --git a/common/x86_power.c b/common/x86_power.c
index a78d878b9e..f82b4ff0d3 100644
--- a/common/x86_power.c
+++ b/common/x86_power.c
@@ -66,7 +66,6 @@ static const char * const state_names[] = {
 #define IN_PCH_SLP_SUSn_DEASSERTED 0x1000
 #define IN_PCH_SLP_MEn_DEASSERTED  0x2000
 #define IN_PCH_SUSWARNn_DEASSERTED 0x4000
-#define IN_PCH_BKLTEN_ASSERTED     0x8000
 /* All always-on supplies */
 #define IN_PGOOD_ALWAYS_ON   (IN_PGOOD_5VALW)
 /* All non-core power rails */
@@ -133,12 +132,6 @@ static void update_in_signals(void)
 	/* Copy SUSWARN# signal from PCH to SUSACK# */
 	gpio_set_level(GPIO_PCH_SUSACKn, v);
 
-	v = gpio_get_level(GPIO_PCH_BKLTEN);
-	if (v)
-		inew |= IN_PCH_BKLTEN_ASSERTED;
-	/* Copy backlight enable signal from PCH to BKLTEN */
-	gpio_set_level(GPIO_ENABLE_BACKLIGHT, v);
-
 	in_signals = inew;
 }
 
diff --git a/include/pwm.h b/include/pwm.h
index 022a21399b..26e5fa4686 100644
--- a/include/pwm.h
+++ b/include/pwm.h
@@ -10,29 +10,32 @@
 
 #include "common.h"
 
-/* Initializes the module. */
+/* Initialize the module. */
 int pwm_init(void);
 
-/* Enables/disables the fan.  This should be called by whatever function
+/* Enable/disable the fan.  This should be called by whatever function
  * enables the power supply to the fan. */
 int pwm_enable_fan(int enable);
 
-/* Gets the current fan RPM. */
+/* Get the current fan RPM. */
 int pwm_get_fan_rpm(void);
 
 /* Get the target fan RPM. */
 int pwm_get_fan_target_rpm(void);
 
-/* Sets the target fan RPM.  Pass -1 to set fan to maximum. */
+/* Set the target fan RPM.  Pass -1 to set fan to maximum. */
 int pwm_set_fan_target_rpm(int rpm);
 
-/* Gets the keyboard backlight percentage (0=off, 100=max). */
+/* Enable/disable the keyboard backlight. */
+int pwm_enable_keyboard_backlight(int enable);
+
+/* Get the keyboard backlight percentage (0=off, 100=max). */
 int pwm_get_keyboard_backlight(void);
 
-/* Sets the keyboard backlight percentage (0=off, 100=max). */
+/* Set the keyboard backlight percentage (0=off, 100=max). */
 int pwm_set_keyboard_backlight(int percent);
 
-/* Sets the power LED brightness to the specified percent (0=off, 100=max). */
+/* Set the power LED brightness to the specified percent (0=off, 100=max). */
 int pwm_set_power_led(int percent);
 
 #endif  /* __CROS_EC_PWM_H */