90 lines
2.5 KiB
C
90 lines
2.5 KiB
C
/*
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* (C) Copyright 2002
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* Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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/* stuff specific for the sc520, but independent of implementation */
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#include <common.h>
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#include <asm/io.h>
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#include <asm/interrupt.h>
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#include <asm/ic/sc520.h>
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void sc520_timer_isr(void)
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{
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/* Ack the GP Timer Interrupt */
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writeb(0x02, &sc520_mmcr->gptmrsta);
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}
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int timer_init(void)
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{
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/* Register the SC520 specific timer interrupt handler */
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register_timer_isr (sc520_timer_isr);
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/* Install interrupt handler for GP Timer 1 */
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irq_install_handler (0, timer_isr, NULL);
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/* Map GP Timer 1 to Master PIC IR0 */
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writeb(0x01, &sc520_mmcr->gp_tmr_int_map[1]);
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/* Disable GP Timers 1 & 2 - Allow configuration writes */
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writew(0x4000, &sc520_mmcr->gptmr1ctl);
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writew(0x4000, &sc520_mmcr->gptmr2ctl);
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/* Reset GP Timers 1 & 2 */
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writew(0x0000, &sc520_mmcr->gptmr1cnt);
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writew(0x0000, &sc520_mmcr->gptmr2cnt);
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/* Setup GP Timer 2 as a 100kHz (10us) prescaler */
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writew(83, &sc520_mmcr->gptmr2maxcmpa);
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writew(0xc001, &sc520_mmcr->gptmr2ctl);
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/* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */
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writew(100, &sc520_mmcr->gptmr1maxcmpa);
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writew(0xe009, &sc520_mmcr->gptmr1ctl);
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unmask_irq (0);
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/* Clear the GP Timer 1 status register to get the show rolling*/
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writeb(0x02, &sc520_mmcr->gptmrsta);
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return 0;
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}
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/* Allow boards to override udelay implementation */
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void __udelay(unsigned long usec)
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__attribute__((weak, alias("sc520_udelay")));
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void sc520_udelay(unsigned long usec)
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{
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int m = 0;
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long u;
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long temp;
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temp = readw(&sc520_mmcr->swtmrmilli);
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temp = readw(&sc520_mmcr->swtmrmicro);
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do {
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m += readw(&sc520_mmcr->swtmrmilli);
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u = readw(&sc520_mmcr->swtmrmicro) + (m * 1000);
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} while (u < usec);
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}
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