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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [include/] [asm-arm/] [arch-mx1ads/] [time.h] - Rev 1276
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/* * linux/include/asm-arm/arch-mx1ads/time.h * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Copyright (C) 2002 Shane Nay (shane@minirl.com) */ #include <asm/system.h> /* * Where is the timer (VA)? */ #define TIMER0_VA_BASE (IO_ADDRESS(MX1ADS_TIM1_BASE)+0x00000000) #define TIMER1_VA_BASE (IO_ADDRESS(MX1ADS_TIM2_BASE)+0x00000000) /* * How long is the timer interval? * * Note- * Clocking is not accurate enough. Need to change the input * to CLKOUT, and fix what those values are. However, * first need to evaluate what a reasonable value is * as several other things depend upon that clock. * */ #define TIMER_RELOAD (328) #define TICKS2USECS(x) ((x) * 30) #define TIM_32KHZ 0x08 #define TIM_INTEN 0x10 #define TIM_ENAB 0x01 /* * What does it look like? */ typedef struct TimerStruct { unsigned long TimerControl; unsigned long TimerPrescaler; unsigned long TimerCompare; unsigned long TimerCapture; unsigned long TimerCounter; unsigned long TimerClear; /* Clear Status */ } TimerStruct_t; extern unsigned long (*gettimeoffset) (void); /* * Returns number of ms since last clock interrupt. Note that interrupts * will have been disabled by do_gettimeoffset() */ static unsigned long mx1ads_gettimeoffset(void) { volatile TimerStruct_t *timer1 = (TimerStruct_t *) TIMER1_VA_BASE; unsigned long ticks, status; /* * Get the current number of ticks. Note that there is a race * condition between us reading the timer and checking for * an interrupt. We get around this by ensuring that the * counter has not reloaded between our two reads. */ ticks = timer1->TimerCounter; /* * Interrupt pending? If so, we've reloaded once already. */ if (timer1->TimerClear & 1) ticks += TIMER_RELOAD; /* * Convert the ticks to usecs */ return TICKS2USECS(ticks); } /* * IRQ handler for the timer */ static void mx1ads_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *) TIMER1_VA_BASE; // ...clear the interrupt if (timer1->TimerClear) { timer1->TimerClear = 0x0; } do_timer(regs); do_profile(regs); } /* * Set up timer interrupt, and return the current time in seconds. */ static inline void setup_timer(void) { volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *) TIMER0_VA_BASE; volatile TimerStruct_t *timer1 = (volatile TimerStruct_t *) TIMER1_VA_BASE; timer_irq.handler = mx1ads_timer_interrupt; /* * Initialise to a known state (all timers off, and timing reset) */ timer0->TimerControl = 0; timer1->TimerControl = 0; timer0->TimerPrescaler = 0; timer1->TimerPrescaler = 0; timer1->TimerCompare = 328; timer1->TimerControl = (TIM_32KHZ | TIM_INTEN | TIM_ENAB); /* * Make irqs happen for the system timer */ setup_arm_irq(TIM2_INT, &timer_irq); gettimeoffset = mx1ads_gettimeoffset; }
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