iris/boot-programs/buzzer.ccp

#pypp 0
// Iris: micro-kernel for a capability-based operating system.
// boot-programs/buzzer.ccp: Piezo buzzer driver.
// 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"

class DevBuzzer:
	static unsigned const pwm = 4
	Kernel::Cap event
	bool is_beeping
	public:
	DevBuzzer ():
		is_beeping = false
		tcu_stop_counter (pwm)
		tcu_select_extalclk (pwm)
		tcu_select_clk_div64 (pwm)
		tcu_enable_pwm_output (pwm)
	void stop ():
		if !is_beeping:
			return
		tcu_stop_counter (pwm)
		event.invoke ()
		Kernel::free_cap (event)
		is_beeping = false
	void beep (unsigned freq, unsigned ms, Kernel::Cap cb):
		stop ()
		event = cb
		unsigned full = JZ_EXTAL / 64 / freq
		tcu_set_full_data (pwm, full)
		tcu_set_half_data (pwm, full / 2)
		tcu_set_count (pwm, 0)
		tcu_start_counter (pwm)
		Kernel::my_receiver.set_alarm (ms * HZ / 1000)
		is_beeping = true

enum codes:
	BUZZER = 32

Kernel::Num start ():
	Kernel::schedule ()
	map_tcu ()

	DevBuzzer buzzer

	Device dev = Kernel::my_receiver.create_capability (BUZZER)
	Kernel::my_parent.provide_device <Buzzer> (dev.copy ())
	Kernel::free_cap (dev)
	unsigned user (~0)
	unsigned next_user (0)
	while true:
		Kernel::wait ()
		switch Kernel::recv.protected_data.h:
			case ~0:
				// Alarm.
				buzzer.stop ()
				break
			case 0:
				switch Kernel::recv.protected_data.l:
					case BUZZER:
						// Buzzer device control request.
						switch Kernel::recv.data[0].l:
							case Device::CREATE_USER:
								Kernel::Cap reply = Kernel::get_reply ()
								Keyboard cap = Kernel::my_receiver.create_capability (Kernel::Num (next_user++, BUZZER))
								reply.invoke (0, 0, cap.copy ())
								Kernel::free_cap (cap)
								Kernel::free_cap (reply)
								break
							case Device::DESTROY_USER:
								Kernel::recv.reply.invoke ()
								break
							case Device::UNUSE:
								buzzer.stop ()
								Kernel::recv.reply.invoke ()
								break
							case Device::USE:
								Kernel::Cap reply = Kernel::get_reply ()
								user = Kernel::my_receiver.get_protected (Kernel::recv.arg).l
								reply.invoke ()
								Kernel::free_cap (reply)
								break
							default:
								kdebug ("invalid buzzer control command: ")
								kdebug_num (Kernel::recv.data[0].l)
								kdebug ("\n")
								break
						break
					default:
						kdebug ("invalid buzzer request\n")
						break
				break
			case BUZZER:
				// Buzzer device user request.
				if Kernel::recv.protected_data.l != user:
					kdebug ("invalid user requesting buzzer\n")
					Kernel::recv.reply.invoke ()
					break
				switch Kernel::recv.data[0].l:
					case Buzzer::BEEP:
						// Volume is not used by this buzzer.
						Kernel::Cap arg = Kernel::get_arg ()
						Kernel::Cap reply = Kernel::get_reply ()
						buzzer.beep (Kernel::recv.data[1].l, Kernel::recv.data[1].h, arg)
						reply.invoke ()
						Kernel::free_cap (reply)
						break
					case Buzzer::STOP:
						buzzer.stop ()
						Kernel::recv.reply.invoke ()
						break
					default:
						kdebug ("Buzzer: other\n")
						break
				break
			default:
				kdebug ("Buzzer: unknown num: ")
				kdebug_num (Kernel::recv.protected_data.h)
				kdebug ("\n")