iris/boot-programs/gpio.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// boot-programs/gpio.ccp: GPIO driver, controlling all devices without special hardware.
// Copyright 2009 Bas Wijnen <wijnen@debian.org>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

#include "devices.hh"
#define ARCH
#include "arch.hh"

// Interval between polls for keyboard (when keys are pressed) and battery/power (always) events
#define ALARM_INTERVAL (HZ / 20)

// GPIO pins for the devices (port.pin)

// keyboard
// Cols = 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 3.10, 3.11, 3.12, 3.13, 3.14, 3.15, 3.29
// Rows = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7
// For some reason, it only works if the rows are input and the columns are output.
// interrupts: yes, with all columns set to output 0, the first key press can be detected as an interrupt; some other events also trigger interrupts.

// touchpad buttons
// Left: 0.16
// Right: 0.13
// interrupts: yes, for any change.

// Lock leds
// Num lock: 2.22
// Caps lock: 0.27
// Scroll lock: 0.9
// interrupts: no, output only.

// Power output (setting to 0 switches off the machine): 2.2
// interrupts: no, output only.

// Power button: 3.1 (note that this is also a keyboard column.)
// Battery presence and charge detection: 3.29 (note that this is also a keyboard column.)
// interrupts: no; it would be possible, but setting these to input makes it impossible to detect certain key presses as interrupts.

// interrupt summary
// Port 0: pin 0, 1, 2, 3, 4, 5, 6, 7: keyboard; 13, 16: touchpad
// Port 1: None.
// Port 2: None.
// Port 3: None.

enum event_type:
	KEYBOARD_EVENT
	TOUCHPAD_EVENT
	POWERBUTTON_EVENT
	BATTERY_EVENT
	NUM_EVENTS

enum cap_type:
	CAP_KEYBOARD = 32
	CAP_TOUCHPAD
	CAP_POWEROFF
	CAP_POWERBUTTON
	CAP_BATTERY
	CAP_LOCKLEDS
	CAP_PWM

static Capability cbs[NUM_EVENTS]

static void event (event_type type, unsigned data):
	if !cbs[type]:
		return
	invoke_01 (cbs[type], data)

static void set_cb (event_type type, Capability cb):
	if cbs[type]:
		drop (cbs[type])
	cbs[type] = cb

enum battery_type:
	BATTERY_ABSENT
	BATTERY_CHARGING
	BATTERY_CHARGED

class Keyboard:
	unsigned keys[GPIO_KBD_NUM_COLS]
	bool scanning
	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 |= KEYBOARD_RELEASE
				event (KEYBOARD_EVENT, code)
		keys[col] = data
		// If any keys are pressed, scanning is required.
		if data != GPIO_KBD_ROW_MASK:
			scanning = true
	public:
	bool is_scanning ():
		return scanning
	void scan ():
		// 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
		// Set scanning to false before first parse.
		scanning = false
		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])
			for unsigned i = 0; i < 100000; ++i:
				GPIO_GPDIR (GPIO_KBD_COL_PORT) = dir | (1 << cols[col])
			unsigned data = GPIO_GPDR (GPIO_KBD_ROW_PORT) & GPIO_KBD_ROW_MASK
			parse (col, data)
			// set pin
			GPIO_GPDR (GPIO_KBD_COL_PORT) = dat | (1 << cols[col])
			// input
			GPIO_GPDIR (GPIO_KBD_COL_PORT) = dir
		// 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
		// Set interrupts on change.
		unsigned data = GPIO_GPDR (GPIO_KBD_ROW_PORT)
		for unsigned i = 0; i < 8; ++i:
			if data & (1 << i):
				gpio_irq_fall (GPIO_KBD_ROW_PORT, i)
			else:
				gpio_irq_rise (GPIO_KBD_ROW_PORT, i)
		// Clear pending interrupts.
		GPIO_GPFR (GPIO_KBD_ROW_PORT) |= GPIO_KBD_ROW_MASK
		// Reenable interrupts.
		GPIO_GPIER (GPIO_KBD_ROW_PORT) |= GPIO_KBD_ROW_MASK
	Keyboard ():
		// 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_GPPUR (GPIO_KBD_ROW_PORT) |= GPIO_KBD_ROW_MASK
		GPIO_GPDIR (GPIO_KBD_ROW_PORT) &= ~GPIO_KBD_ROW_MASK
		// 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 ()

class Touchpad:
	unsigned old_state
	public:
	void check_events ():
		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)
			if (state ^ old_state) & (1 << GPIO_TP_LEFT):
				event (TOUCHPAD_EVENT, 0x10000)
		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)
			if (state ^ old_state) & (1 << GPIO_TP_RIGHT):
				event (TOUCHPAD_EVENT, 0x10001)
		old_state = state
		// Ack interrupts.
		GPIO_GPFR (GPIO_TP_LEFT_PORT) = (1 << GPIO_TP_LEFT) | (1 << GPIO_TP_RIGHT)
	Touchpad ():
		// Set pins to input with pull-ups.
		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)
		old_state = 0
		// See if they are already pressed.  Also set up interrupts.
		check_events ()
		// Now enable the interrupts.

class Lockleds:
	// Note that num lock is in port 2.  The others are in port 0.
	public:
	Lockleds ():
		gpio_as_output (GPIO_NUM_PORT, GPIO_NUM)
		gpio_as_output (GPIO_CAPS_PORT, GPIO_CAPS)
		gpio_as_output (GPIO_SCROLL_PORT, GPIO_SCROLL)
		GPIO_GPDR (GPIO_NUM_PORT) |= 1 << GPIO_NUM
		GPIO_GPDR (GPIO_CAPS_PORT) |= 1 << GPIO_CAPS
		GPIO_GPDR (GPIO_SCROLL_PORT) |= 1 << GPIO_SCROLL
	void set (unsigned state):
		if state & 4:
			GPIO_GPDR (GPIO_NUM_PORT) &= ~(1 << GPIO_NUM)
		else:
			GPIO_GPDR (GPIO_NUM_PORT) |= 1 << GPIO_NUM
		if state & 2:
			GPIO_GPDR (GPIO_CAPS_PORT) &= ~(1 << GPIO_CAPS)
		else:
			GPIO_GPDR (GPIO_CAPS_PORT) |= 1 << GPIO_CAPS
		if state & 1:
			GPIO_GPDR (GPIO_SCROLL_PORT) &= ~(1 << GPIO_SCROLL)
		else:
			GPIO_GPDR (GPIO_SCROLL_PORT) |= 1 << GPIO_SCROLL

class Power:
	// Power out is in port 2, the rest in port 3.
	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)
		GPIO_GPPUR (3) &= ~(PWR_IN | BATTERY)
		//udelay (100)
		unsigned state = GPIO_GPDR (3)
		if (state ^ old_state) & PWR_IN:
			event (POWERBUTTON_EVENT, state & PWR_IN ? 0 : 0x10000)
		if (state ^ old_state) & BATTERY:
			if !(state & BATTERY):
				GPIO_GPPUR (3) |= BATTERY
				//udelay (100)
				if GPIO_GPDR (3) & BATTERY:
					if !was_present:
						event (BATTERY_EVENT, BATTERY_CHARGED)
					was_present = true
				else:
					if was_present:
						event (BATTERY_EVENT, BATTERY_ABSENT)
					was_present = false
			else:
				event (BATTERY_EVENT, BATTERY_CHARGING)
		old_state = state
		GPIO_GPPUR (3) &= ~BATTERY
		GPIO_GPDIR (3) &= ~(PWR_IN | BATTERY)
		//udelay (100)
		GPIO_GPIER (3) |= 0xff
		#endif
	Power ():
		was_present = true
		//old_state = BATTERY
		poll ()
	void poweroff ():
		// 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 ():
		wdt_set_count (0xffffffff - 32)
		wdt_start ()
		while true:
			// Do nothing; wait until the device reboots.

// Not really a gpio device, but it's so small, and uses gpio, so I include it here to avoid ipc.
class Pwm:
	public:
	Pwm ():
		GPIO_GPDIR (GPIO_PWM_ENABLE_PORT) |= 1 << GPIO_PWM_ENABLE
		PWM_PER (0) = 300
	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_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 ():
	map_gpio ()
	map_pwm0 ()
	map_wdt ()
	map_i2c ()

	Keyboard kbd
	Touchpad tp
	Lockleds leds
	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)
	Capability cap_tp = receiver_create_capability (__my_receiver, CAP_TOUCHPAD)
	Capability cap_poweroff = receiver_create_capability (__my_receiver, CAP_POWEROFF)
	Capability cap_powerbutton = receiver_create_capability (__my_receiver, CAP_POWERBUTTON)
	Capability cap_battery = receiver_create_capability (__my_receiver, CAP_BATTERY)
	Capability cap_lockleds = receiver_create_capability (__my_receiver, CAP_LOCKLEDS)
	Capability cap_pwm = receiver_create_capability (__my_receiver, CAP_PWM)

	invoke_41 (__my_parent, cap_copy (cap_kbd), cap_copy (cap_tp), cap_copy (cap_poweroff), cap_copy (cap_powerbutton), INIT_SET_GPIO_0)
	invoke_31 (__my_parent, cap_copy (cap_battery), cap_copy (cap_lockleds), cap_copy (cap_pwm), INIT_SET_GPIO_1)

	receiver_set_alarm (__my_receiver, ALARM_INTERVAL)
	while true:
		schedule ()
		Message msg
		wait (&msg)
		switch msg.protected_data:
			case ~0:
				// Alarm.
				// Periodically scan several devices.
				if kbd.is_scanning ():
					kbd.scan ()
				power.poll ()
				receiver_set_alarm (__my_receiver, ALARM_INTERVAL)
				break
			case IRQ_GPIO0:
				// Always scan keyboard and touchpad on any interrupt.
				kbd.scan ()
				tp.check_events ()
				// Reregister the interrupt.
				register_interrupt (IRQ_GPIO0)
				break
			case CAP_KEYBOARD:
				set_cb (KEYBOARD_EVENT, msg.cap[0])
				break
			case CAP_TOUCHPAD:
				set_cb (TOUCHPAD_EVENT, msg.cap[0])
				break
			case CAP_POWEROFF:
				if msg.data[0]:
					power.poweroff ()
				else:
					power.reboot ()
				break
			case CAP_POWERBUTTON:
				set_cb (POWERBUTTON_EVENT, msg.cap[0])
				break
			case CAP_BATTERY:
				set_cb (BATTERY_EVENT, msg.cap[0])
				break
			case CAP_LOCKLEDS:
				leds.set (msg.data[0])
				break
			case CAP_PWM:
				pwm.set_backlight (msg.data[0])
				break