/* * linux/include/asm-arm/arch-ebsa110/time.h * * Copyright (c) 1996,1997,1998 Russell King. * * No real time clock on the evalulation board! * * Changelog: * 10-Oct-1996 RMK Created * 04-Dec-1997 RMK Updated for new arch/arm/kernel/time.c * 07-Aug-1998 RMK Updated for arch/arm/kernel/leds.c * 28-Dec-1998 APH Made leds code optional */ #include #define MCLK_47_8 #if defined(MCLK_42_3) #define PIT1_COUNT 0xecbe #elif defined(MCLK_47_8) /* * This should be 0x10B43, but that doesn't exactly fit. * We run the timer interrupt at 5ms, and then divide it by * two in software... This is so that the user processes * see exactly the same model whichever ARM processor they're * running on. */ #define PIT1_COUNT 0x85A1 #define DIVISOR 2 #endif static void timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { *PIT_T1 = (PIT1_COUNT) & 0xff; *PIT_T1 = (PIT1_COUNT) >> 8; #ifdef DIVISOR { static unsigned int divisor; if (divisor--) return; divisor = DIVISOR - 1; } #endif do_leds(); do_timer(regs); } /* * Set up timer interrupt. */ extern __inline__ void setup_timer(void) { /* * Timer 1, mode 0, 16-bit, autoreload */ *PIT_CTRL = 0x70; /* * Refresh counter clocked at 47.8MHz/7 = 146.4ns * We want centi-second interrupts */ *PIT_T1 = (PIT1_COUNT) & 0xff; *PIT_T1 = (PIT1_COUNT) >> 8; timer_irq.handler = timer_interrupt; setup_arm_irq(IRQ_EBSA110_TIMER0, &timer_irq); }