summaryrefslogtreecommitdiff
path: root/arch/mips/kernel/cevt-bcm1480.c
blob: d39a2963b4511686ab1868e3f58ebd29e50419f0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2000,2001,2004 Broadcom Corporation
 */
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/irq.h>

#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/time.h>

#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_scd.h>

#include <asm/sibyte/sb1250.h>

#define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
#define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
#define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2

/*
 * The general purpose timer ticks at 1MHz independent if
 * the rest of the system
 */

static int sibyte_set_periodic(struct clock_event_device *evt)
{
	unsigned int cpu = smp_processor_id();
	void __iomem *cfg, *init;

	cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
	init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));

	__raw_writeq(0, cfg);
	__raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
	__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, cfg);
	return 0;
}

static int sibyte_shutdown(struct clock_event_device *evt)
{
	unsigned int cpu = smp_processor_id();
	void __iomem *cfg;

	cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));

	/* Stop the timer until we actually program a shot */
	__raw_writeq(0, cfg);
	return 0;
}

static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
{
	unsigned int cpu = smp_processor_id();
	void __iomem *cfg, *init;

	cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
	init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));

	__raw_writeq(0, cfg);
	__raw_writeq(delta - 1, init);
	__raw_writeq(M_SCD_TIMER_ENABLE, cfg);

	return 0;
}

static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
{
	unsigned int cpu = smp_processor_id();
	struct clock_event_device *cd = dev_id;
	void __iomem *cfg;
	unsigned long tmode;

	if (clockevent_state_periodic(cd))
		tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
	else
		tmode = 0;

	/* ACK interrupt */
	cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
	____raw_writeq(tmode, cfg);

	cd->event_handler(cd);

	return IRQ_HANDLED;
}

static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
static DEFINE_PER_CPU(char [18], sibyte_hpt_name);

void sb1480_clockevent_init(void)
{
	unsigned int cpu = smp_processor_id();
	unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
	struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
	unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
	unsigned long flags =  IRQF_PERCPU | IRQF_TIMER;

	BUG_ON(cpu > 3);	/* Only have 4 general purpose timers */

	sprintf(name, "bcm1480-counter-%d", cpu);
	cd->name		= name;
	cd->features		= CLOCK_EVT_FEAT_PERIODIC |
				  CLOCK_EVT_FEAT_ONESHOT;
	clockevent_set_clock(cd, V_SCD_TIMER_FREQ);
	cd->max_delta_ns	= clockevent_delta2ns(0x7fffff, cd);
	cd->max_delta_ticks	= 0x7fffff;
	cd->min_delta_ns	= clockevent_delta2ns(2, cd);
	cd->min_delta_ticks	= 2;
	cd->rating		= 200;
	cd->irq			= irq;
	cd->cpumask		= cpumask_of(cpu);
	cd->set_next_event	= sibyte_next_event;
	cd->set_state_shutdown	= sibyte_shutdown;
	cd->set_state_periodic	= sibyte_set_periodic;
	cd->set_state_oneshot	= sibyte_shutdown;
	clockevents_register_device(cd);

	bcm1480_mask_irq(cpu, irq);

	/*
	 * Map the timer interrupt to IP[4] of this cpu
	 */
	__raw_writeq(IMR_IP4_VAL,
		     IOADDR(A_BCM1480_IMR_REGISTER(cpu,
			R_BCM1480_IMR_INTERRUPT_MAP_BASE_H) + (irq << 3)));

	bcm1480_unmask_irq(cpu, irq);

	irq_set_affinity(irq, cpumask_of(cpu));
	if (request_irq(irq, sibyte_counter_handler, flags, name, cd))
		pr_err("Failed to request irq %d (%s)\n", irq, name);
}