602f536940
The functions pit_init and pit_wait_wraparound were previously marked as PHYS_CODE, despite being called from BOOT_CODE elsewhere. This bug has been present for some time but can be masked by the compiler inlining all the involved functions, which is what typically happens.
49 lines
1.1 KiB
C
49 lines
1.1 KiB
C
/*
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* Copyright 2014, General Dynamics C4 Systems
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*
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* This software may be distributed and modified according to the terms of
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* the GNU General Public License version 2. Note that NO WARRANTY is provided.
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* See "LICENSE_GPLv2.txt" for details.
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*
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* @TAG(GD_GPL)
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*/
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#include <arch/linker.h>
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#include <plat/machine/io.h>
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#include <plat/machine/pit.h>
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/* PIT (i8253) registers */
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#define PIT_MODE 0x43
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#define PIT_CH0 0x40
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/* Count frequency in Hz */
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#define PIT_HZ 1193180
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BOOT_CODE void
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pit_init(void)
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{
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uint16_t divisor = (PIT_HZ * PIT_WRAPAROUND_MS) / 1000;
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out8(PIT_MODE, 0x34); /* Set mode 2 and wait for divisor bytes */
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out8(PIT_CH0, divisor & 0xff); /* Set low byte of divisor */
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out8(PIT_CH0, divisor >> 8); /* Set high byte of divisor */
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}
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BOOT_CODE void
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pit_wait_wraparound(void)
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{
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uint16_t count;
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uint16_t count_old;
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out8(PIT_MODE, 0x00);
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count = in8(PIT_CH0);
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count |= (in8(PIT_CH0) << 8);
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count_old = count;
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while (count <= count_old) {
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count_old = count;
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out8(PIT_MODE, 0x00);
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count = in8(PIT_CH0);
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count |= (in8(PIT_CH0) << 8);
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}
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}
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