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"

// 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.

// 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:
	enum { NUM_COLS = 17 }
	enum { COL_MASK = 0x2000ffff }
	enum { ROW_MASK = 0x000000ff }

	unsigned keys[NUM_COLS]
	bool scanning

	public:
	bool is_scanning ():
		return scanning
	Keyboard ():
		// Set all columns to input and disable the pull-ups.
		GPIO_GPDIR (3) &= ~COL_MASK
		GPIO_GPPUR (3) &= ~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:
			keys[i] = 0xff
	void scan ():
		// Set all columns to 0 when the become output.
		GPIO_GPDR (3) &= ~COL_MASK
		bool key_pressed = 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:
				key_pressed = true
		if key_pressed:
			scanning = true

class Touchpad:
	unsigned old_state
	public:
	enum buttons:
		LEFT = 1 << 16
		RIGHT = 1 << 13
	void check_events ():
		unsigned state = GPIO_GPDR (0)
		if (state ^ old_state) & LEFT:
			if state & LEFT:
				GPIO_GPIDUR (0) = (GPIO_GPIDUR (0) & (3 << (2 * 0))) | (GPIO_IRQ_FALLEDG << (2 * 0))
				event (TOUCHPAD_EVENT, 0)
			else:
				GPIO_GPIDUR (0) = (GPIO_GPIDUR (0) & (3 << (2 * 0))) | (GPIO_IRQ_RAISEDG << (2 * 0))
				event (TOUCHPAD_EVENT, 0x10000)
		if (state ^ old_state) & RIGHT:
			if state & RIGHT:
				GPIO_GPIDLR (0) = (GPIO_GPIDLR (0) & (3 << (2 * 13))) | (GPIO_IRQ_FALLEDG << (2 * 13))
				event (TOUCHPAD_EVENT, 1)
			else:
				GPIO_GPIDLR (0) = (GPIO_GPIDLR (0) & (3 << (2 * 13))) | (GPIO_IRQ_RAISEDG << (2 * 13))
				event (TOUCHPAD_EVENT, 0x10001)
		old_state = state
	Touchpad ():
		// Set pins to input with pull-ups.
		GPIO_GPDIR (0) &= ~(LEFT | RIGHT)
		GPIO_GPPUR (0) |= LEFT | RIGHT
		// Enable interrupts.
		GPIO_GPIDUR (0) = (GPIO_GPIDUR (0) & (3 << (2 * 0))) | (GPIO_IRQ_FALLEDG << (2 * 0))
		GPIO_GPIDLR (0) = (GPIO_GPIDLR (0) & (3 << (2 * 13))) | (GPIO_IRQ_FALLEDG << (2 * 13))
		old_state = 0
		// See if they are already pressed.  If so, the interrupt detection is changed.
		check_events ()
		// Now enable the interrupts.
		GPIO_GPIER (0) |= LEFT | 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_GPDR (2) &= ~NUM
		GPIO_GPDR (0) &= ~(SCROLL | CAPS)
		GPIO_GPDIR (2) |= NUM
		GPIO_GPDIR (0) |= CAPS | SCROLL
	void set (unsigned state):
		if state & 4:
			GPIO_GPDR (2) &= ~NUM
		else:
			GPIO_GPDR (2) |= NUM
		if state & 2:
			GPIO_GPDR (0) &= ~CAPS
		else:
			GPIO_GPDR (0) |= CAPS
		if state & 1:
			GPIO_GPDR (0) &= ~SCROLL
		else:
			GPIO_GPDR (0) |= SCROLL

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 ():
		// 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
	Power ():
		GPIO_GPDR (2) |= PWR_OUT
		GPIO_GPDIR (2) |= PWR_OUT
		was_present = true
		old_state = BATTERY
		poll ()
	void poweroff ():
		GPIO_GPDR (2) &= ~PWR_OUT
		GPIO_GPDIR (2) |= PWR_OUT
		while true:
			// Do nothing; wait until the device stops running.

// 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
		PWM_PER (0) = 300
	void set_backlight (bool state):
		if state:
			PWM_DUT (0) = 300
			PWM_CTR (0) = 0xbf
			GPIO_GPDR (2) |= PWM_ENABLE
		else:
			PWM_DUT (0) = 0
			PWM_CTR (0) = 0x3f
			GPIO_GPDR (2) &= ~PWM_ENABLE
	// TODO: make it really work as a pwm instead of a switch; check if pwm1 is connected to anything.

int main ():
	for unsigned i = 0; i < 10; ++i:
		schedule ()
	*(unsigned *)~3 = 0

	map_gpio ()
	map_pwm0 ()

	Keyboard kbd
	Touchpad tp
	//Lockleds leds
	Power power
	Pwm pwm

	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, HZ / 5)
	while true:
		Message msg
		wait (&msg)
		switch msg.protected_data:
			case ~0:
				// Alarm.
				if kbd.is_scanning ():
					kbd.scan ()
				power.poll ()
				receiver_set_alarm (__my_receiver, HZ / 5)
				break
			case IRQ_GPIO0:
				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 & (Touchpad::LEFT | Touchpad::RIGHT):
					tp.check_events ()
			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:
				power.poweroff ()
				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