1b2441318SGreg Kroah-Hartman // SPDX-License-Identifier: GPL-2.0
21da177e4SLinus Torvalds /*
31da177e4SLinus Torvalds * linux/arch/m68k/hp300/time.c
41da177e4SLinus Torvalds *
51da177e4SLinus Torvalds * Copyright (C) 1998 Philip Blundell <philb@gnu.org>
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * This file contains the HP300-specific time handling code.
81da177e4SLinus Torvalds */
91da177e4SLinus Torvalds
101da177e4SLinus Torvalds #include <asm/ptrace.h>
112ed16626SFinn Thain #include <linux/clocksource.h>
121da177e4SLinus Torvalds #include <linux/types.h>
131da177e4SLinus Torvalds #include <linux/init.h>
141da177e4SLinus Torvalds #include <linux/sched.h>
151da177e4SLinus Torvalds #include <linux/kernel_stat.h>
161da177e4SLinus Torvalds #include <linux/interrupt.h>
171da177e4SLinus Torvalds #include <asm/machdep.h>
181da177e4SLinus Torvalds #include <asm/irq.h>
191da177e4SLinus Torvalds #include <asm/io.h>
201da177e4SLinus Torvalds #include <asm/traps.h>
211da177e4SLinus Torvalds #include <asm/blinken.h>
221da177e4SLinus Torvalds
232ed16626SFinn Thain static u64 hp300_read_clk(struct clocksource *cs);
242ed16626SFinn Thain
252ed16626SFinn Thain static struct clocksource hp300_clk = {
262ed16626SFinn Thain .name = "timer",
272ed16626SFinn Thain .rating = 250,
282ed16626SFinn Thain .read = hp300_read_clk,
292ed16626SFinn Thain .mask = CLOCKSOURCE_MASK(32),
302ed16626SFinn Thain .flags = CLOCK_SOURCE_IS_CONTINUOUS,
312ed16626SFinn Thain };
322ed16626SFinn Thain
334be2ba93SFinn Thain static u32 clk_total, clk_offset;
342ed16626SFinn Thain
351da177e4SLinus Torvalds /* Clock hardware definitions */
361da177e4SLinus Torvalds
371da177e4SLinus Torvalds #define CLOCKBASE 0xf05f8000
381da177e4SLinus Torvalds
391da177e4SLinus Torvalds #define CLKCR1 0x1
401da177e4SLinus Torvalds #define CLKCR2 0x3
411da177e4SLinus Torvalds #define CLKCR3 CLKCR1
421da177e4SLinus Torvalds #define CLKSR CLKCR2
431da177e4SLinus Torvalds #define CLKMSB1 0x5
444be2ba93SFinn Thain #define CLKLSB1 0x7
451da177e4SLinus Torvalds #define CLKMSB2 0x9
461da177e4SLinus Torvalds #define CLKMSB3 0xD
471da177e4SLinus Torvalds
484be2ba93SFinn Thain #define CLKSR_INT1 BIT(0)
494be2ba93SFinn Thain
501da177e4SLinus Torvalds /* This is for machines which generate the exact clock. */
511da177e4SLinus Torvalds
522ed16626SFinn Thain #define HP300_TIMER_CLOCK_FREQ 250000
532ed16626SFinn Thain #define HP300_TIMER_CYCLES (HP300_TIMER_CLOCK_FREQ / HZ)
542ed16626SFinn Thain #define INTVAL (HP300_TIMER_CYCLES - 1)
551da177e4SLinus Torvalds
hp300_tick(int irq,void * dev_id)562850bc27SAl Viro static irqreturn_t hp300_tick(int irq, void *dev_id)
571da177e4SLinus Torvalds {
581efdd4bdSFinn Thain unsigned long flags;
591da177e4SLinus Torvalds unsigned long tmp;
601efdd4bdSFinn Thain
611efdd4bdSFinn Thain local_irq_save(flags);
621da177e4SLinus Torvalds in_8(CLOCKBASE + CLKSR);
631da177e4SLinus Torvalds asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));
642ed16626SFinn Thain clk_total += INTVAL;
654be2ba93SFinn Thain clk_offset = 0;
6642f1d57fSArnd Bergmann legacy_timer_tick(1);
67d6444094SArnd Bergmann timer_heartbeat();
681efdd4bdSFinn Thain local_irq_restore(flags);
691efdd4bdSFinn Thain
701da177e4SLinus Torvalds /* Turn off the network and SCSI leds */
711da177e4SLinus Torvalds blinken_leds(0, 0xe0);
721efdd4bdSFinn Thain return IRQ_HANDLED;
731da177e4SLinus Torvalds }
741da177e4SLinus Torvalds
hp300_read_clk(struct clocksource * cs)752ed16626SFinn Thain static u64 hp300_read_clk(struct clocksource *cs)
761da177e4SLinus Torvalds {
772ed16626SFinn Thain unsigned long flags;
784be2ba93SFinn Thain unsigned char lsb, msb, msb_new;
792ed16626SFinn Thain u32 ticks;
801da177e4SLinus Torvalds
812ed16626SFinn Thain local_irq_save(flags);
822ed16626SFinn Thain /* Read current timer 1 value */
834be2ba93SFinn Thain msb = in_8(CLOCKBASE + CLKMSB1);
844be2ba93SFinn Thain again:
854be2ba93SFinn Thain if ((in_8(CLOCKBASE + CLKSR) & CLKSR_INT1) && msb > 0)
864be2ba93SFinn Thain clk_offset = INTVAL;
874be2ba93SFinn Thain lsb = in_8(CLOCKBASE + CLKLSB1);
884be2ba93SFinn Thain msb_new = in_8(CLOCKBASE + CLKMSB1);
894be2ba93SFinn Thain if (msb_new != msb) {
904be2ba93SFinn Thain msb = msb_new;
914be2ba93SFinn Thain goto again;
924be2ba93SFinn Thain }
932ed16626SFinn Thain
944be2ba93SFinn Thain ticks = INTVAL - ((msb << 8) | lsb);
954be2ba93SFinn Thain ticks += clk_offset + clk_total;
962ed16626SFinn Thain local_irq_restore(flags);
972ed16626SFinn Thain
982ed16626SFinn Thain return ticks;
991da177e4SLinus Torvalds }
1001da177e4SLinus Torvalds
hp300_sched_init(void)101*f9a01539SArnd Bergmann void __init hp300_sched_init(void)
1021da177e4SLinus Torvalds {
1031da177e4SLinus Torvalds out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
1041da177e4SLinus Torvalds out_8(CLOCKBASE + CLKCR1, 0x1); /* reset */
1051da177e4SLinus Torvalds
1061da177e4SLinus Torvalds asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
1071da177e4SLinus Torvalds
10842f1d57fSArnd Bergmann if (request_irq(IRQ_AUTO_6, hp300_tick, IRQF_TIMER, "timer tick", NULL))
1098bd3968bSGeert Uytterhoeven pr_err("Couldn't register timer interrupt\n");
1101da177e4SLinus Torvalds
1111da177e4SLinus Torvalds out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
1121da177e4SLinus Torvalds out_8(CLOCKBASE + CLKCR1, 0x40); /* enable irq */
1132ed16626SFinn Thain
1142ed16626SFinn Thain clocksource_register_hz(&hp300_clk, HP300_TIMER_CLOCK_FREQ);
1151da177e4SLinus Torvalds }
116