1 /* 2 * (C) Copyright 2002 3 * Daniel Engstr�m, Omicron Ceti AB <daniel@omicron.se>. 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 /* stuff specific for the sc520, but independent of implementation */ 25 26 #include <common.h> 27 #include <asm/io.h> 28 #include <asm/interrupt.h> 29 #include <asm/ic/sc520.h> 30 31 void sc520_timer_isr(void) 32 { 33 /* Ack the GP Timer Interrupt */ 34 writeb(0x02, &sc520_mmcr->gptmrsta); 35 } 36 37 int timer_init(void) 38 { 39 /* Register the SC520 specific timer interrupt handler */ 40 register_timer_isr (sc520_timer_isr); 41 42 /* Install interrupt handler for GP Timer 1 */ 43 irq_install_handler (0, timer_isr, NULL); 44 45 /* Map GP Timer 1 to Master PIC IR0 */ 46 writeb(0x01, &sc520_mmcr->gp_tmr_int_map[1]); 47 48 /* Disable GP Timers 1 & 2 - Allow configuration writes */ 49 writew(0x4000, &sc520_mmcr->gptmr1ctl); 50 writew(0x4000, &sc520_mmcr->gptmr2ctl); 51 52 /* Reset GP Timers 1 & 2 */ 53 writew(0x0000, &sc520_mmcr->gptmr1cnt); 54 writew(0x0000, &sc520_mmcr->gptmr2cnt); 55 56 /* Setup GP Timer 2 as a 100kHz (10us) prescaler */ 57 writew(83, &sc520_mmcr->gptmr2maxcmpa); 58 writew(0xc001, &sc520_mmcr->gptmr2ctl); 59 60 /* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */ 61 writew(100, &sc520_mmcr->gptmr1maxcmpa); 62 writew(0xe009, &sc520_mmcr->gptmr1ctl); 63 64 unmask_irq (0); 65 66 /* Clear the GP Timer 1 status register to get the show rolling*/ 67 writeb(0x02, &sc520_mmcr->gptmrsta); 68 69 return 0; 70 } 71 72 /* Allow boards to override udelay implementation */ 73 void __udelay(unsigned long usec) 74 __attribute__((weak, alias("sc520_udelay"))); 75 76 void sc520_udelay(unsigned long usec) 77 { 78 int m = 0; 79 long u; 80 long temp; 81 82 temp = readw(&sc520_mmcr->swtmrmilli); 83 temp = readw(&sc520_mmcr->swtmrmicro); 84 85 do { 86 m += readw(&sc520_mmcr->swtmrmilli); 87 u = readw(&sc520_mmcr->swtmrmicro) + (m * 1000); 88 } while (u < usec); 89 } 90