1/* 2 * linux/include/asm-arm/arch-nexuspci/time.h 3 * 4 * Copyright (c) 1997, 1998, 1999, 2000 FutureTV Labs Ltd. 5 * 6 * The FTV PCI card has no real-time clock. We get timer ticks from the 7 * SCC chip. 8 */ 9 10/* 11 * This program is free software; you can redistribute it and/or 12 * modify it under the terms of the GNU General Public License 13 * as published by the Free Software Foundation; either version 14 * 2 of the License, or (at your option) any later version. 15 */ 16 17static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) 18{ 19 static int count = 25; 20 unsigned char stat = __raw_readb(DUART_BASE + 0x14); 21 if (!(stat & 0x10)) 22 return; /* Not for us */ 23 24 /* Reset counter */ 25 __raw_writeb(0x90, DUART_BASE + 8); 26 27 if (--count == 0) { 28 static int state = 1; 29 state ^= 1; 30 __raw_writeb(0x1a + state, INTCONT_BASE); 31 __raw_writeb(0x18 + state, INTCONT_BASE); 32 count = 50; 33 } 34 35 /* Wait for slow rise time */ 36 __raw_readb(DUART_BASE + 0x14); 37 __raw_readb(DUART_BASE + 0x14); 38 __raw_readb(DUART_BASE + 0x14); 39 __raw_readb(DUART_BASE + 0x14); 40 __raw_readb(DUART_BASE + 0x14); 41 __raw_readb(DUART_BASE + 0x14); 42 43 do_timer(regs); 44} 45 46static inline void setup_timer(void) 47{ 48 int tick = 3686400 / 16 / 2 / 100; 49 50 __raw_writeb(tick & 0xff, DUART_BASE + 0x1c); 51 __raw_writeb(tick >> 8, DUART_BASE + 0x18); 52 __raw_writeb(0x80, DUART_BASE + 8); 53 __raw_writeb(0x10, DUART_BASE + 0x14); 54 55 timer_irq.handler = timer_interrupt; 56 timer_irq.flags = SA_SHIRQ; 57 58 setup_arm_irq(IRQ_TIMER, &timer_irq); 59} 60