summaryrefslogtreecommitdiff
path: root/arch/mips/sgi-ip27/ip27-timer.c
blob: 9b4b9ac621a3111c627c486031b248e33365148a (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
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
// SPDX-License-Identifier: GPL-2.0
/*
 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
 * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
 */
#include <linux/bcd.h>
#include <linux/clockchips.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched_clock.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/param.h>
#include <linux/smp.h>
#include <linux/time.h>
#include <linux/timex.h>
#include <linux/mm.h>
#include <linux/platform_device.h>

#include <asm/time.h>
#include <asm/pgtable.h>
#include <asm/sgialib.h>
#include <asm/sn/ioc3.h>
#include <asm/sn/klconfig.h>
#include <asm/sn/arch.h>
#include <asm/sn/addrs.h>
#include <asm/sn/sn_private.h>
#include <asm/sn/sn0/ip27.h>
#include <asm/sn/sn0/hub.h>

#define TICK_SIZE (tick_nsec / 1000)

/* Includes for ioc3_init().  */
#include <asm/sn/types.h>
#include <asm/sn/sn0/addrs.h>
#include <asm/sn/sn0/hubni.h>
#include <asm/sn/sn0/hubio.h>
#include <asm/pci/bridge.h>

static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
{
	unsigned int cpu = smp_processor_id();
	int slice = cputoslice(cpu);
	unsigned long cnt;

	cnt = LOCAL_HUB_L(PI_RT_COUNT);
	cnt += delta;
	LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);

	return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
}

static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
static DEFINE_PER_CPU(char [11], hub_rt_name);

static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
{
	unsigned int cpu = smp_processor_id();
	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
	int slice = cputoslice(cpu);

	/*
	 * Ack
	 */
	LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
	cd->event_handler(cd);

	return IRQ_HANDLED;
}

struct irqaction hub_rt_irqaction = {
	.handler	= hub_rt_counter_handler,
	.percpu_dev_id	= &hub_rt_clockevent,
	.flags		= IRQF_PERCPU | IRQF_TIMER,
	.name		= "hub-rt",
};

/*
 * This is a hack; we really need to figure these values out dynamically
 *
 * Since 800 ns works very well with various HUB frequencies, such as
 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
 *
 * Ralf: which clock rate is used to feed the counter?
 */
#define NSEC_PER_CYCLE		800
#define CYCLES_PER_SEC		(NSEC_PER_SEC / NSEC_PER_CYCLE)

void hub_rt_clock_event_init(void)
{
	unsigned int cpu = smp_processor_id();
	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
	unsigned char *name = per_cpu(hub_rt_name, cpu);

	sprintf(name, "hub-rt %d", cpu);
	cd->name		= name;
	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
	clockevent_set_clock(cd, CYCLES_PER_SEC);
	cd->max_delta_ns	= clockevent_delta2ns(0xfffffffffffff, cd);
	cd->max_delta_ticks	= 0xfffffffffffff;
	cd->min_delta_ns	= clockevent_delta2ns(0x300, cd);
	cd->min_delta_ticks	= 0x300;
	cd->rating		= 200;
	cd->irq			= IP27_RT_TIMER_IRQ;
	cd->cpumask		= cpumask_of(cpu);
	cd->set_next_event	= rt_next_event;
	clockevents_register_device(cd);

	enable_percpu_irq(IP27_RT_TIMER_IRQ, IRQ_TYPE_NONE);
}

static void __init hub_rt_clock_event_global_init(void)
{
	irq_set_handler(IP27_RT_TIMER_IRQ, handle_percpu_devid_irq);
	irq_set_percpu_devid(IP27_RT_TIMER_IRQ);
	setup_percpu_irq(IP27_RT_TIMER_IRQ, &hub_rt_irqaction);
}

static u64 hub_rt_read(struct clocksource *cs)
{
	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}

struct clocksource hub_rt_clocksource = {
	.name	= "HUB-RT",
	.rating = 200,
	.read	= hub_rt_read,
	.mask	= CLOCKSOURCE_MASK(52),
	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
};

static u64 notrace hub_rt_read_sched_clock(void)
{
	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
}

static void __init hub_rt_clocksource_init(void)
{
	struct clocksource *cs = &hub_rt_clocksource;

	clocksource_register_hz(cs, CYCLES_PER_SEC);

	sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
}

void __init plat_time_init(void)
{
	hub_rt_clocksource_init();
	hub_rt_clock_event_global_init();
	hub_rt_clock_event_init();
}

void cpu_time_init(void)
{
	lboard_t *board;
	klcpu_t *cpu;
	int cpuid;

	/* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
	board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
	if (!board)
		panic("Can't find board info for myself.");

	cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
	cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
	if (!cpu)
		panic("No information about myself?");

	printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
}

void hub_rtc_init(cnodeid_t cnode)
{

	/*
	 * We only need to initialize the current node.
	 * If this is not the current node then it is a cpuless
	 * node and timeouts will not happen there.
	 */
	if (get_compact_nodeid() == cnode) {
		LOCAL_HUB_S(PI_RT_EN_A, 1);
		LOCAL_HUB_S(PI_RT_EN_B, 1);
		LOCAL_HUB_S(PI_PROF_EN_A, 0);
		LOCAL_HUB_S(PI_PROF_EN_B, 0);
		LOCAL_HUB_S(PI_RT_COUNT, 0);
		LOCAL_HUB_S(PI_RT_PEND_A, 0);
		LOCAL_HUB_S(PI_RT_PEND_B, 0);
	}
}

static int __init sgi_ip27_rtc_devinit(void)
{
	struct resource res;

	memset(&res, 0, sizeof(res));
	res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
			      IOC3_BYTEBUS_DEV0);
	res.end = res.start + 32767;
	res.flags = IORESOURCE_MEM;

	return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
						      &res, 1));
}

/*
 * kludge make this a device_initcall after ioc3 resource conflicts
 * are resolved
 */
late_initcall(sgi_ip27_rtc_devinit);