diff --git a/boot-programs/gpio.ccp b/boot-programs/gpio.ccp
index 6a8c872..e6b96c7 100644
--- a/boot-programs/gpio.ccp
+++ b/boot-programs/gpio.ccp
@@ -21,7 +21,7 @@
 #include "arch.hh"
 
 // Interval between polls for keyboard (when keys are pressed) and battery/power (always) events
-#define ALARM_INTERVAL (HZ / 10)
+#define ALARM_INTERVAL (HZ / 1)
 
 // GPIO pins for the devices (port.pin)
 
@@ -89,75 +89,89 @@ enum battery_type:
 	BATTERY_CHARGED
 
 class Keyboard:
-	enum { NUM_COLS = 17 }
-	enum { COL_MASK = 0x2000ffff }
-	enum { ROW_MASK = 0x000000ff }
-
-	unsigned keys[NUM_COLS]
-	bool scanning
-
+	unsigned keys[GPIO_KBD_NUM_COLS]
+	void parse (unsigned col, unsigned data):
+		for unsigned row = 0; row < GPIO_KBD_NUM_ROWS; ++row:
+			if (data ^ keys[col]) & (1 << row):
+				unsigned code = (col << 3) | row
+				if data & (1 << row):
+					code |= 0x10000
+				event (KEYBOARD_EVENT, code)
+		keys[col] = data
 	public:
-	bool is_scanning ():
-		return scanning
+	void scan ():
+		kdebug ("keyboard scan\n")
+		// Disable interrupts during scan.
+		GPIO_GPIER (GPIO_KBD_ROW_PORT) &= ~GPIO_KBD_ROW_MASK
+		// All columns are input.
+		GPIO_GPDIR (GPIO_KBD_COL_PORT) &= ~GPIO_KBD_COL_MASK
+		int const cols[GPIO_KBD_NUM_COLS] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 29 }
+		unsigned dir = GPIO_GPDIR (GPIO_KBD_COL_PORT) & ~GPIO_KBD_COL_MASK
+		unsigned dat = GPIO_GPDR (GPIO_KBD_COL_PORT) & ~GPIO_KBD_COL_MASK
+		unsigned data
+		for unsigned col = 0; col < GPIO_KBD_NUM_COLS; ++col:
+			// clear pin
+			GPIO_GPDR (GPIO_KBD_COL_PORT) = dat
+			// output
+			GPIO_GPDIR (GPIO_KBD_COL_PORT) = dir | (1 << cols[col])
+			// Generate events of previous column.  Do that now, so there is a short delay for the data to stabilize.
+			if col != 0:
+				parse (col - 1, data)
+			else:
+				// Add a short delay for stabilization.
+				parse (0, keys[0])
+			data = GPIO_GPDR (GPIO_KBD_ROW_PORT) & GPIO_KBD_ROW_MASK
+			// set pin
+			GPIO_GPDR (GPIO_KBD_COL_PORT) = dat | (1 << cols[col])
+			// input
+			GPIO_GPDIR (GPIO_KBD_COL_PORT) = dir
+		parse (GPIO_KBD_NUM_COLS - 1, data)
+		// set all to 0.
+		GPIO_GPDR (GPIO_KBD_COL_PORT) = dat
+		// set all to output.
+		GPIO_GPDIR (GPIO_KBD_COL_PORT) = dir | GPIO_KBD_COL_MASK
+		// clear pending interrupts.
+		for unsigned i = 0; i < 8; ++i:
+			GPIO_GPFR (GPIO_KBD_ROW_PORT) |= 1 << i
+		// Reenable interrupts.
+		GPIO_GPIER (GPIO_KBD_ROW_PORT) |= GPIO_KBD_ROW_MASK
 	Keyboard ():
-		// Set all columns to input and disable the pull-ups.
-		GPIO_GPDIR (3) &= ~COL_MASK
-		GPIO_GPPUR (3) &= ~COL_MASK
+		// Set all columns to output without pull-ups when set as input.
+		GPIO_GPPUR (GPIO_KBD_COL_PORT) &= ~GPIO_KBD_COL_MASK
+		GPIO_GPDIR (GPIO_KBD_COL_PORT) |= GPIO_KBD_COL_MASK
 
 		// Set all rows to input and enable the pull-ups.
-		GPIO_GPDIR (0) &= ~ROW_MASK
-		GPIO_GPPUR (0) |= ROW_MASK
-		// Enable interrupts on falling edge.
-		GPIO_GPIDLR (0) = (GPIO_GPIDLR (0) & 0xffff) | (GPIO_IRQ_FALLEDG * 0xaaaa)
-		GPIO_GPIER (0) |= 0xff
-		scanning = false
-
-		for unsigned i = 0; i < NUM_COLS; ++i:
+		GPIO_GPPUR (GPIO_KBD_ROW_PORT) |= GPIO_KBD_ROW_MASK
+		GPIO_GPDIR (GPIO_KBD_ROW_PORT) &= ~GPIO_KBD_ROW_MASK
+		// Detect interrupts on falling edge.
+		for unsigned i = 0; i < GPIO_KBD_NUM_ROWS; ++i:
+			gpio_irq_fall (GPIO_KBD_ROW_PORT, i)
+		// Initialize matrix.
+		for unsigned i = 0; i < GPIO_KBD_NUM_COLS; ++i:
 			keys[i] = 0xff
+		// Perform initial scan to get real values into matrix and set up the rest.
 		scan ()
-	void scan ():
-		// Set all columns to 0 when they become output.
-		GPIO_GPDR (3) &= ~COL_MASK
-		scanning = false
-		int const cols[NUM_COLS] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 29 }
-		for unsigned col = 0; col < NUM_COLS; ++col:
-			GPIO_GPDIR (3) = (GPIO_GPDIR (3) & ~COL_MASK) | (1 << cols[col])
-			//udelay (100)
-			unsigned data = GPIO_GPDR (0) & ROW_MASK
-			// Generate events.
-			for unsigned row = 0; row < 8; ++row:
-				if (data ^ keys[col]) & (1 << row):
-					unsigned code = (row << 8) | col
-					if data & (1 << row):
-						code |= 0x10000
-					event (KEYBOARD_EVENT, code)
-			keys[col] = data
-			if data != ROW_MASK:
-				scanning = true
-		scanning = true
-		if scanning:
-			GPIO_GPDIR (3) &= ~COL_MASK
-		else:
-			GPIO_GPDIR (3) |= COL_MASK
 
 class Touchpad:
 	unsigned old_state
 	public:
 	void check_events ():
-		unsigned state = GPIO_GPDR (0)
-		if (state ^ old_state) & (1 << GPIO_TP_LEFT):
-			if state & (1 << GPIO_TP_LEFT):
-				gpio_irq_fall (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
+		unsigned state = GPIO_GPDR (GPIO_TP_LEFT_PORT)
+		if state & (1 << GPIO_TP_LEFT):
+			gpio_irq_fall (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
+			if (state ^ old_state) & (1 << GPIO_TP_LEFT):
 				event (TOUCHPAD_EVENT, 0)
-			else:
-				gpio_irq_rise (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
+		else:
+			gpio_irq_rise (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
+			if (state ^ old_state) & (1 << GPIO_TP_LEFT):
 				event (TOUCHPAD_EVENT, 0x10000)
-		if (state ^ old_state) & (1 << GPIO_TP_RIGHT):
-			if state & (1 << GPIO_TP_RIGHT):
-				gpio_irq_fall (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
+		if state & (1 << GPIO_TP_RIGHT):
+			gpio_irq_fall (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
+			if (state ^ old_state) & (1 << GPIO_TP_RIGHT):
 				event (TOUCHPAD_EVENT, 1)
-			else:
-				gpio_irq_rise (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
+		else:
+			gpio_irq_rise (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
+			if (state ^ old_state) & (1 << GPIO_TP_RIGHT):
 				event (TOUCHPAD_EVENT, 0x10001)
 		old_state = state
 	Touchpad ():
@@ -165,20 +179,13 @@ class Touchpad:
 		gpio_as_input (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
 		gpio_as_input (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
 		GPIO_GPPUR (0) |= (1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT)
-		// Set up interrupts.
-		gpio_irq_rise (GPIO_TP_LEFT_PORT, GPIO_TP_LEFT)
-		gpio_irq_rise (GPIO_TP_RIGHT_PORT, GPIO_TP_RIGHT)
 		old_state = 0
-		// See if they are already pressed.  If so, the interrupt detection is changed.
+		// See if they are already pressed.  Also set up interrupts.
 		check_events ()
 		// Now enable the interrupts.
-		GPIO_GPIER (0) |= (1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT)
 
 class Lockleds:
 	// Note that num lock is in port 2.  The others are in port 0.
-	enum { NUM = 1 << 22 }
-	enum { CAPS = 1 << 27 }
-	enum { SCROLL = 1 << 9 }
 	public:
 	Lockleds ():
 		gpio_as_output (GPIO_NUM_PORT, GPIO_NUM)
@@ -203,13 +210,11 @@ class Lockleds:
 
 class Power:
 	// Power out is in port 2, the rest in port 3.
-	enum { PWR_OUT = 1 << 2 }
-	enum { PWR_IN = 1 << 1 }
-	enum { BATTERY = 1 << 29 }
 	unsigned old_state
 	bool was_present
 	public:
 	void poll ():
+		#if 0
 		// Switch off keyboard interrupts, because this may interfere with them.
 		GPIO_GPIER (0) &= ~0xff
 		GPIO_GPDIR (3) &= ~(PWR_IN | BATTERY)
@@ -237,16 +242,16 @@ class Power:
 		GPIO_GPDIR (3) &= ~(PWR_IN | BATTERY)
 		//udelay (100)
 		GPIO_GPIER (3) |= 0xff
+		#endif
 	Power ():
-		GPIO_GPDR (2) |= PWR_OUT
-		GPIO_GPDIR (2) |= PWR_OUT
 		was_present = true
-		old_state = BATTERY
+		//old_state = BATTERY
 		poll ()
 	void poweroff ():
-		gpio_as_gpio (GPIO_PW_O_PORT, GPIO_PW_O)
-		gpio_as_output (GPIO_PW_O_PORT, GPIO_PW_O)
-		GPIO_GPDR (GPIO_PW_O) &= ~(1 << GPIO_PW_O)
+		// TODO: doesn't work.
+		i2c_open ()
+		i2c_write_page (I2C_DEV_MCU, I2C_MCU_SHUTDOWN, "\1", 1)
+		i2c_close ()
 		while true:
 			// Do nothing; wait until the device stops running.
 	void reboot ():
@@ -257,29 +262,27 @@ class Power:
 
 // Not really a gpio device, but it's so small, and uses gpio, so I include it here to avoid ipc.
 class Pwm:
-	// Pin definitions, all in port 2.
-	enum { PWM_ENABLE = 1 << 30 }
 	public:
 	Pwm ():
-		GPIO_GPDIR (2) |= PWM_ENABLE
+		GPIO_GPDIR (GPIO_PWM_ENABLE_PORT) |= 1 << GPIO_PWM_ENABLE
 		PWM_PER (0) = 300
-	void set_backlight (bool state):
-		if state:
-			PWM_DUT (0) = 300
-			PWM_CTR (0) = 0xbf
-			GPIO_GPDR (2) |= PWM_ENABLE
+	void set_backlight (unsigned level):
+		if level > 300:
+			level = 300
+		PWM_DUT (0) = level
+		if level:
+			PWM_CTR (0) = 0x80
+			GPIO_GPDR (GPIO_PWM_ENABLE_PORT) |= 1 << GPIO_PWM_ENABLE
 		else:
-			PWM_DUT (0) = 0
-			PWM_CTR (0) = 0x3f
-			GPIO_GPDR (2) &= ~PWM_ENABLE
+			PWM_CTR (0) = 0x00
+			GPIO_GPDR (GPIO_PWM_ENABLE_PORT) &= ~(1 << GPIO_PWM_ENABLE)
 	// TODO: make it really work as a pwm instead of a switch; check if pwm1 is connected to anything.
 
 int main ():
-	schedule ()
-
 	map_gpio ()
 	map_pwm0 ()
 	map_wdt ()
+	map_i2c ()
 
 	Keyboard kbd
 	Touchpad tp
@@ -287,6 +290,8 @@ int main ():
 	Power power
 	Pwm pwm
 
+	// Enable interrupts.  All are in port 0.
+	GPIO_GPIER (GPIO_KBD_ROW_PORT) = (1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT) | GPIO_KBD_ROW_MASK
 	register_interrupt (IRQ_GPIO0)
 
 	Capability cap_kbd = receiver_create_capability (__my_receiver, CAP_KEYBOARD)
@@ -302,25 +307,27 @@ int main ():
 
 	receiver_set_alarm (__my_receiver, ALARM_INTERVAL)
 	while true:
+		schedule ()
 		Message msg
 		wait (&msg)
 		switch msg.protected_data:
 			case ~0:
 				// Alarm.
-				if kbd.is_scanning ():
-					kbd.scan ()
-				//power.poll ()
+				kdebug ("alarm\n")
+				// Periodically scan several devices.
+				kbd.scan ()
+				power.poll ()
 				receiver_set_alarm (__my_receiver, ALARM_INTERVAL)
 				break
 			case IRQ_GPIO0:
-				kdebug ("gpio interrupt")
-				unsigned irq = GPIO_GPFR (0)
-				// Ack all.  This works because they are all edge triggered.
-				GPIO_GPFR (0) = irq
-				if irq & 0xff:
-					kbd.scan ()
-				if irq & ((1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT)):
-					tp.check_events ()
+				kdebug ("gpio interrupt\n")
+				//unsigned irq = GPIO_GPFR (0)
+				// Ack all.
+				GPIO_GPFR (0) = (1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT) | GPIO_KBD_ROW_MASK
+				// Always scan keyboard and touchpad on any interrupt.
+				kbd.scan ()
+				tp.check_events ()
+				// Reregister the interrupt.
 				register_interrupt (IRQ_GPIO0)
 				break
 			case CAP_KEYBOARD:
diff --git a/boot-programs/init.ccp b/boot-programs/init.ccp
index a619f2b..d93127b 100644
--- a/boot-programs/init.ccp
+++ b/boot-programs/init.ccp
@@ -39,7 +39,7 @@ static void setup ():
 		wait (&msg)
 		switch msg.data[0]:
 			case INIT_SET_GPIO_0:
-				kdebug ("gpio 0")
+				kdebug ("gpio 0\n")
 				kbd = msg.cap[0]
 				tp = msg.cap[1]
 				poweroff = msg.cap[2]
@@ -47,14 +47,14 @@ static void setup ():
 				++state
 				break
 			case INIT_SET_GPIO_1:
-				kdebug ("gpio 1")
+				kdebug ("gpio 1\n")
 				battery = msg.cap[0]
 				lockleds = msg.cap[1]
 				pwm = msg.cap[2]
 				++state
 				break
 			case INIT_SET_LCD:
-				kdebug ("lcd")
+				kdebug ("lcd\n")
 				lcd = msg.cap[0]
 				++state
 				break
@@ -67,10 +67,11 @@ static void setup ():
 	invoke_01 (pwm, 1)
 
 int main ():
+	// Set up lcd first
 	schedule ()
-	kdebug ("start init")
+	kdebug ("start init\n")
 	setup ()
-	kdebug ("run init")
+	kdebug ("run init\n")
 	while true:
 		Message msg
 		wait (&msg)
@@ -81,9 +82,14 @@ int main ():
 				kdebug_char ('\n')
 				break
 			case TP:
-				if msg.data[0] == 0:
-					// Press left button.
-					invoke_00 (poweroff)
+				unsigned leds = 0
+				if msg.data[0] & 1:
+					leds |= 0x1
+				else:
+					leds |= 0x4
+				if !(msg.data[0] & 0x10000):
+					leds |= 0x2
+				invoke_01 (lockleds, leds)
 				break
 			case POWERBUTTON:
 				kdebug ("powerbutton event\n")
diff --git a/iris.h b/iris.h
index 34f54bd..37a1d9f 100644
--- a/iris.h
+++ b/iris.h
@@ -30,7 +30,7 @@ extern "C" {
 #endif
 
 // Number of clock interrupts per second.
-#define HZ 10
+#define HZ 20
 
 #define PAGE_BITS (12)
 #define PAGE_SIZE (1 << PAGE_BITS)
@@ -441,6 +441,20 @@ static void invoke_41 (Capability t, Capability c0, Capability c1, Capability c2
 	invoke (t, &msg);
 }
 
+static void call_00 (Capability c)
+{
+	Message msg;
+	msg.cap[0] = c;
+	msg.data[0] = 0;
+	msg.data[1] = 0;
+	msg.data[2] = 0;
+	msg.data[3] = 0;
+	msg.cap[1] = 0;
+	msg.cap[2] = 0;
+	msg.cap[3] = 0;
+	call (__my_call, &msg);
+}
+
 static Capability call_c01 (Capability c, unsigned d)
 {
 	Message msg;
@@ -760,7 +774,6 @@ static unsigned memory_limit (Capability memory, unsigned limit)
 
 static void drop (Capability cap)
 {
-	return;
 	invoke_11 (__my_memory, cap, CAP_MEMORY_DROP);
 }
 
diff --git a/mips/jz4730.hhp b/mips/jz4730.hhp
index e8b54de..34e1e36 100644
--- a/mips/jz4730.hhp
+++ b/mips/jz4730.hhp
@@ -1399,8 +1399,15 @@ static void __map_io (unsigned physical, unsigned mapping):
 #define I2C_SR_DRF		(1 << 1)
 #define I2C_SR_ACKF		(1 << 0)
 
+#define I2C_WRITE		0
+#define I2C_READ		1
 
-
+/* I2C devices */
+#define I2C_DEV_MCU		0x48
+/* I2C device registers */
+#define I2C_MCU_SHUTDOWN	0xd8
+#define I2C_MCU_BAT_STATUS	0xdb
+#define I2C_MCU_BAT_CHARGE	0xd9
 
 /*************************************************************************
  * UDC		usb device controller (unused in trendtac)
@@ -2821,8 +2828,8 @@ static __inline__ unsigned msc_calc_slow_clk_divisor (bool is_sd):
 
 #define GPIO_PW_I_PORT		3
 #define GPIO_PW_I			1
-#define GPIO_PW_O_PORT		2
-#define GPIO_PW_O			2
+#define GPIO_MCU_PORT		2
+#define GPIO_MCU			1
 #define GPIO_LED_EN_PORT	2
 #define GPIO_LED_EN			28
 #define GPIO_DISP_OFF_N_PORT	2
@@ -2847,6 +2854,15 @@ static __inline__ unsigned msc_calc_slow_clk_divisor (bool is_sd):
 #define GPIO_TP_LEFT			16
 #define GPIO_TP_RIGHT_PORT	0
 #define GPIO_TP_RIGHT			13
+#define GPIO_PWM_ENABLE_PORT	2
+#define GPIO_PWM_ENABLE			30
+#define GPIO_KBD_NUM_ROWS	8
+#define GPIO_KBD_NUM_COLS	17
+#define GPIO_KBD_COL_PORT	3
+#define GPIO_KBD_COL_MASK	0x2000ffff
+#define GPIO_KBD_ROW_PORT	0
+#define GPIO_KBD_ROW_MASK	0x000000ff
+#define GPIO_KBD_ROW_HALF	0x00005555
 
 #define GPIO_HALF(x) (((x) & 0xf) << 1)
 
@@ -3012,6 +3028,48 @@ static __inline__ void gpio_as_cim ():
 #define i2c_read()		( I2C_DR )
 #define i2c_write(val)	( I2C_DR = (val) )
 
+#ifndef __KERNEL
+static __inline__ void i2c_open ():
+	i2c_set_clk (JZ_EXTAL, 10000)
+	i2c_enable ()
+
+// Note that this kills messages from the queue.
+static __inline__ void i2c_close ():
+	Message msg
+	receiver_set_alarm (__my_receiver, 3 * HZ / 10)
+	call_00 (0)
+	i2c_disable ()
+
+static __inline__ bool i2c_send (unsigned data):
+	unsigned timeout = 10000
+	i2c_write (data)
+	i2c_set_drf ()
+	while i2c_check_drf () != 0:
+	while !i2c_transmit_ended ():
+	while !i2c_received_ack ():
+		if !--timeout:
+			return false
+	return true
+
+static __inline__ unsigned i2c_write_page (unsigned dev, unsigned addr, char const *data, unsigned count):
+	unsigned timeout = 5
+	i2c_send_start ()
+	if !i2c_send ((dev << 1) | I2C_WRITE):
+		i2c_send_stop ()
+		return 0
+	if !i2c_send (addr):
+		i2c_send_stop ()
+		return 0
+	if count > 8:
+		count = 8
+	unsigned i
+	for i = 0; i < count; ++i:
+		if !i2c_send (*data++):
+			break
+	i2c_send_stop ()
+	return i
+#endif
+
 /***************************************************************************
  * UDC
  ***************************************************************************/