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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/arch/m68k/hp300/time.c
4 *
5 * Copyright (C) 1998 Philip Blundell <philb@gnu.org>
6 *
7 * This file contains the HP300-specific time handling code.
8 */
9
10#include <asm/ptrace.h>
11#include <linux/clocksource.h>
12#include <linux/types.h>
13#include <linux/init.h>
14#include <linux/sched.h>
15#include <linux/kernel_stat.h>
16#include <linux/interrupt.h>
17#include <asm/machdep.h>
18#include <asm/irq.h>
19#include <asm/io.h>
20#include <asm/traps.h>
21#include <asm/blinken.h>
22
23static u64 hp300_read_clk(struct clocksource *cs);
24
25static struct clocksource hp300_clk = {
26 .name = "timer",
27 .rating = 250,
28 .read = hp300_read_clk,
29 .mask = CLOCKSOURCE_MASK(32),
30 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
31};
32
33static u32 clk_total, clk_offset;
34
35/* Clock hardware definitions */
36
37#define CLOCKBASE 0xf05f8000
38
39#define CLKCR1 0x1
40#define CLKCR2 0x3
41#define CLKCR3 CLKCR1
42#define CLKSR CLKCR2
43#define CLKMSB1 0x5
44#define CLKLSB1 0x7
45#define CLKMSB2 0x9
46#define CLKMSB3 0xD
47
48#define CLKSR_INT1 BIT(0)
49
50/* This is for machines which generate the exact clock. */
51
52#define HP300_TIMER_CLOCK_FREQ 250000
53#define HP300_TIMER_CYCLES (HP300_TIMER_CLOCK_FREQ / HZ)
54#define INTVAL (HP300_TIMER_CYCLES - 1)
55
56static irqreturn_t hp300_tick(int irq, void *dev_id)
57{
58 irq_handler_t timer_routine = dev_id;
59 unsigned long flags;
60 unsigned long tmp;
61
62 local_irq_save(flags);
63 in_8(CLOCKBASE + CLKSR);
64 asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));
65 clk_total += INTVAL;
66 clk_offset = 0;
67 timer_routine(0, NULL);
68 local_irq_restore(flags);
69
70 /* Turn off the network and SCSI leds */
71 blinken_leds(0, 0xe0);
72 return IRQ_HANDLED;
73}
74
75static u64 hp300_read_clk(struct clocksource *cs)
76{
77 unsigned long flags;
78 unsigned char lsb, msb, msb_new;
79 u32 ticks;
80
81 local_irq_save(flags);
82 /* Read current timer 1 value */
83 msb = in_8(CLOCKBASE + CLKMSB1);
84again:
85 if ((in_8(CLOCKBASE + CLKSR) & CLKSR_INT1) && msb > 0)
86 clk_offset = INTVAL;
87 lsb = in_8(CLOCKBASE + CLKLSB1);
88 msb_new = in_8(CLOCKBASE + CLKMSB1);
89 if (msb_new != msb) {
90 msb = msb_new;
91 goto again;
92 }
93
94 ticks = INTVAL - ((msb << 8) | lsb);
95 ticks += clk_offset + clk_total;
96 local_irq_restore(flags);
97
98 return ticks;
99}
100
101void __init hp300_sched_init(irq_handler_t vector)
102{
103 out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
104 out_8(CLOCKBASE + CLKCR1, 0x1); /* reset */
105
106 asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
107
108 if (request_irq(IRQ_AUTO_6, hp300_tick, IRQF_TIMER, "timer tick", vector))
109 pr_err("Couldn't register timer interrupt\n");
110
111 out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
112 out_8(CLOCKBASE + CLKCR1, 0x40); /* enable irq */
113
114 clocksource_register_hz(&hp300_clk, HP300_TIMER_CLOCK_FREQ);
115}
1/*
2 * linux/arch/m68k/hp300/time.c
3 *
4 * Copyright (C) 1998 Philip Blundell <philb@gnu.org>
5 *
6 * This file contains the HP300-specific time handling code.
7 */
8
9#include <asm/ptrace.h>
10#include <linux/types.h>
11#include <linux/init.h>
12#include <linux/sched.h>
13#include <linux/kernel_stat.h>
14#include <linux/interrupt.h>
15#include <asm/machdep.h>
16#include <asm/irq.h>
17#include <asm/io.h>
18#include <asm/traps.h>
19#include <asm/blinken.h>
20
21/* Clock hardware definitions */
22
23#define CLOCKBASE 0xf05f8000
24
25#define CLKCR1 0x1
26#define CLKCR2 0x3
27#define CLKCR3 CLKCR1
28#define CLKSR CLKCR2
29#define CLKMSB1 0x5
30#define CLKMSB2 0x9
31#define CLKMSB3 0xD
32
33/* This is for machines which generate the exact clock. */
34#define USECS_PER_JIFFY (1000000/HZ)
35
36#define INTVAL ((10000 / 4) - 1)
37
38static irqreturn_t hp300_tick(int irq, void *dev_id)
39{
40 unsigned long tmp;
41 irq_handler_t vector = dev_id;
42 in_8(CLOCKBASE + CLKSR);
43 asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));
44 /* Turn off the network and SCSI leds */
45 blinken_leds(0, 0xe0);
46 return vector(irq, NULL);
47}
48
49u32 hp300_gettimeoffset(void)
50{
51 /* Read current timer 1 value */
52 unsigned char lsb, msb1, msb2;
53 unsigned short ticks;
54
55 msb1 = in_8(CLOCKBASE + 5);
56 lsb = in_8(CLOCKBASE + 7);
57 msb2 = in_8(CLOCKBASE + 5);
58 if (msb1 != msb2)
59 /* A carry happened while we were reading. Read it again */
60 lsb = in_8(CLOCKBASE + 7);
61 ticks = INTVAL - ((msb2 << 8) | lsb);
62 return ((USECS_PER_JIFFY * ticks) / INTVAL) * 1000;
63}
64
65void __init hp300_sched_init(irq_handler_t vector)
66{
67 out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
68 out_8(CLOCKBASE + CLKCR1, 0x1); /* reset */
69
70 asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
71
72 if (request_irq(IRQ_AUTO_6, hp300_tick, 0, "timer tick", vector))
73 pr_err("Couldn't register timer interrupt\n");
74
75 out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
76 out_8(CLOCKBASE + CLKCR1, 0x40); /* enable irq */
77}