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72 lines
2.1 KiB
72 lines
2.1 KiB
/* |
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* Copyright (C) 2014 René Kijewski <rene.kijewski@fu-berlin.de> |
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* |
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* This library is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* This library is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with this library; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/** |
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* @ingroup x86-irq |
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* @{ |
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* |
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* @file |
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* @brief Configuration and interrupt handling for the Programmable Interval Timer (PIT). |
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* |
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* @author René Kijewski <rene.kijewski@fu-berlin.de> |
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* |
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* @} |
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*/ |
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#include "x86_interrupts.h" |
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#include "x86_pit.h" |
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#include "x86_ports.h" |
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#include "cpu.h" |
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#include "irq.h" |
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#include <stdio.h> |
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void x86_init_pit(void) |
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{ |
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puts("PIT initialized"); |
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} |
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uint16_t x86_pit_read(unsigned channel) |
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{ |
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unsigned old_flags = irq_disable(); |
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outb(PIT_COMMAND_PORT, (channel - 1) << 6 | PIT_ACCESS_MODE_LATCH_COUNT); |
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uint16_t lohi = inb(PIT_CHANNEL_0_PORT + channel - 1); |
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lohi += inb(PIT_CHANNEL_0_PORT + channel - 1) << 8; |
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irq_restore(old_flags); |
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return lohi; |
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} |
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void x86_pit_set2(unsigned channel, unsigned mode, uint16_t max) |
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{ |
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unsigned old_flags = irq_disable(); |
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outb(PIT_COMMAND_PORT, ((channel - 1) << 6) | mode | PIT_ACCESS_MODE_LO_HI); |
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outb(PIT_CHANNEL_0_PORT + channel - 1, max & 0xff); |
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outb(PIT_CHANNEL_0_PORT + channel - 1, max >> 8); |
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irq_restore(old_flags); |
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} |
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bool x86_pit_set(unsigned channel, unsigned mode, unsigned hz) |
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{ |
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if (PIT_MIN_HZ > hz || hz > PIT_MAX_HZ) { |
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return false; |
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} |
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uint16_t max = PIT_MAX_HZ / hz; |
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x86_pit_set2(channel, mode, max); |
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return true; |
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}
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