* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB, <daniel@omicron.se>
*
- * See file CREDITS for list of people who contributed to this
- * project.
- *
- * 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
+ * SPDX-License-Identifier: GPL-2.0+
*/
#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;
-
-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;
-
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;
- }
- }
-
-}