/*
* (C) Copyright 2002
- * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
+ * Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
* See file CREDITS for list of people who contributed to this
* project.
#include <common.h>
#include <asm/io.h>
#include <asm/i8254.h>
-#include <asm/ibmpc.h>
-#include <asm/interrupt.h>
-#define TIMER0_VALUE 0x04aa /* 1kHz 1.9318MHz / 1000 */
#define TIMER2_VALUE 0x0a8e /* 440Hz */
-static int timer_init_done = 0;
-
-int timer_init(void)
+int pcat_timer_init(void)
{
- /* initialize timer 0 and 2
- *
- * Timer 0 is used to increment system_tick 1000 times/sec
- * Timer 1 was used for DRAM refresh in early PC's
- * Timer 2 is used to drive the speaker
- * (to stasrt a beep: write 3 to port 0x61,
+ /*
+ * initialize 2, used to drive the speaker
+ * (to start a beep: write 3 to port 0x61,
* to stop it again: write 0)
*/
- outb (PIT_CMD_CTR0 | PIT_CMD_BOTH | PIT_CMD_MODE2,
- PIT_BASE + PIT_COMMAND);
- outb (TIMER0_VALUE & 0xff, PIT_BASE + PIT_T0);
- outb (TIMER0_VALUE >> 8, PIT_BASE + PIT_T0);
-
- outb (PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
- PIT_BASE + PIT_COMMAND);
- outb (TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
- outb (TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);
-
- irq_install_handler (0, timer_isr, NULL);
- unmask_irq (0);
-
- timer_init_done = 1;
+ outb(PIT_CMD_CTR2 | PIT_CMD_BOTH | PIT_CMD_MODE3,
+ PIT_BASE + PIT_COMMAND);
+ outb(TIMER2_VALUE & 0xff, PIT_BASE + PIT_T2);
+ outb(TIMER2_VALUE >> 8, PIT_BASE + PIT_T2);
return 0;
}
-
-static u16 read_pit(void)
-{
- u8 low;
-
- outb (PIT_CMD_LATCH, PIT_BASE + PIT_COMMAND);
- low = inb (PIT_BASE + PIT_T0);
-
- return ((inb (PIT_BASE + PIT_T0) << 8) | low);
-}
-
-/* this is not very exact */
-void __udelay (unsigned long usec)
-{
- int counter;
- int wraps;
-
- if (timer_init_done)
- {
- counter = read_pit ();
- wraps = usec / 1000;
- usec = usec % 1000;
-
- usec *= 1194;
- usec /= 1000;
- usec += counter;
-
- while (usec > 1194) {
- usec -= 1194;
- wraps++;
- }
-
- while (1) {
- int new_count = read_pit ();
-
- if (((new_count < usec) && !wraps) || wraps < 0)
- break;
-
- if (new_count > counter)
- wraps--;
-
- counter = new_count;
- }
- }
-
-}