1/*
2 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
4 */
5#include <linux/bcd.h>
6#include <linux/clockchips.h>
7#include <linux/init.h>
8#include <linux/kernel.h>
9#include <linux/sched.h>
10#include <linux/sched_clock.h>
11#include <linux/interrupt.h>
12#include <linux/kernel_stat.h>
13#include <linux/param.h>
14#include <linux/smp.h>
15#include <linux/time.h>
16#include <linux/timex.h>
17#include <linux/mm.h>
18#include <linux/platform_device.h>
19
20#include <asm/time.h>
21#include <asm/pgtable.h>
22#include <asm/sgialib.h>
23#include <asm/sn/ioc3.h>
24#include <asm/sn/klconfig.h>
25#include <asm/sn/arch.h>
26#include <asm/sn/addrs.h>
27#include <asm/sn/sn_private.h>
28#include <asm/sn/sn0/ip27.h>
29#include <asm/sn/sn0/hub.h>
30
31#define TICK_SIZE (tick_nsec / 1000)
32
33/* Includes for ioc3_init().  */
34#include <asm/sn/types.h>
35#include <asm/sn/sn0/addrs.h>
36#include <asm/sn/sn0/hubni.h>
37#include <asm/sn/sn0/hubio.h>
38#include <asm/pci/bridge.h>
39
40static void enable_rt_irq(struct irq_data *d)
41{
42}
43
44static void disable_rt_irq(struct irq_data *d)
45{
46}
47
48static struct irq_chip rt_irq_type = {
49	.name		= "SN HUB RT timer",
50	.irq_mask	= disable_rt_irq,
51	.irq_unmask	= enable_rt_irq,
52};
53
54static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
55{
56	unsigned int cpu = smp_processor_id();
57	int slice = cputoslice(cpu);
58	unsigned long cnt;
59
60	cnt = LOCAL_HUB_L(PI_RT_COUNT);
61	cnt += delta;
62	LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
63
64	return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
65}
66
67static void rt_set_mode(enum clock_event_mode mode,
68		struct clock_event_device *evt)
69{
70	/* Nothing to do ...  */
71}
72
73unsigned int rt_timer_irq;
74
75static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
76static DEFINE_PER_CPU(char [11], hub_rt_name);
77
78static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
79{
80	unsigned int cpu = smp_processor_id();
81	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
82	int slice = cputoslice(cpu);
83
84	/*
85	 * Ack
86	 */
87	LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
88	cd->event_handler(cd);
89
90	return IRQ_HANDLED;
91}
92
93struct irqaction hub_rt_irqaction = {
94	.handler	= hub_rt_counter_handler,
95	.flags		= IRQF_PERCPU | IRQF_TIMER,
96	.name		= "hub-rt",
97};
98
99/*
100 * This is a hack; we really need to figure these values out dynamically
101 *
102 * Since 800 ns works very well with various HUB frequencies, such as
103 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
104 *
105 * Ralf: which clock rate is used to feed the counter?
106 */
107#define NSEC_PER_CYCLE		800
108#define CYCLES_PER_SEC		(NSEC_PER_SEC / NSEC_PER_CYCLE)
109
110void hub_rt_clock_event_init(void)
111{
112	unsigned int cpu = smp_processor_id();
113	struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
114	unsigned char *name = per_cpu(hub_rt_name, cpu);
115	int irq = rt_timer_irq;
116
117	sprintf(name, "hub-rt %d", cpu);
118	cd->name		= name;
119	cd->features		= CLOCK_EVT_FEAT_ONESHOT;
120	clockevent_set_clock(cd, CYCLES_PER_SEC);
121	cd->max_delta_ns	= clockevent_delta2ns(0xfffffffffffff, cd);
122	cd->min_delta_ns	= clockevent_delta2ns(0x300, cd);
123	cd->rating		= 200;
124	cd->irq			= irq;
125	cd->cpumask		= cpumask_of(cpu);
126	cd->set_next_event	= rt_next_event;
127	cd->set_mode		= rt_set_mode;
128	clockevents_register_device(cd);
129}
130
131static void __init hub_rt_clock_event_global_init(void)
132{
133	int irq;
134
135	do {
136		smp_wmb();
137		irq = rt_timer_irq;
138		if (irq)
139			break;
140
141		irq = allocate_irqno();
142		if (irq < 0)
143			panic("Allocation of irq number for timer failed");
144	} while (xchg(&rt_timer_irq, irq));
145
146	irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
147	setup_irq(irq, &hub_rt_irqaction);
148}
149
150static cycle_t hub_rt_read(struct clocksource *cs)
151{
152	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
153}
154
155struct clocksource hub_rt_clocksource = {
156	.name	= "HUB-RT",
157	.rating = 200,
158	.read	= hub_rt_read,
159	.mask	= CLOCKSOURCE_MASK(52),
160	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
161};
162
163static u64 notrace hub_rt_read_sched_clock(void)
164{
165	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
166}
167
168static void __init hub_rt_clocksource_init(void)
169{
170	struct clocksource *cs = &hub_rt_clocksource;
171
172	clocksource_register_hz(cs, CYCLES_PER_SEC);
173
174	sched_clock_register(hub_rt_read_sched_clock, 52, CYCLES_PER_SEC);
175}
176
177void __init plat_time_init(void)
178{
179	hub_rt_clocksource_init();
180	hub_rt_clock_event_global_init();
181	hub_rt_clock_event_init();
182}
183
184void cpu_time_init(void)
185{
186	lboard_t *board;
187	klcpu_t *cpu;
188	int cpuid;
189
190	/* Don't use ARCS.  ARCS is fragile.  Klconfig is simple and sane.  */
191	board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
192	if (!board)
193		panic("Can't find board info for myself.");
194
195	cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
196	cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
197	if (!cpu)
198		panic("No information about myself?");
199
200	printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
201
202	set_c0_status(SRB_TIMOCLK);
203}
204
205void hub_rtc_init(cnodeid_t cnode)
206{
207
208	/*
209	 * We only need to initialize the current node.
210	 * If this is not the current node then it is a cpuless
211	 * node and timeouts will not happen there.
212	 */
213	if (get_compact_nodeid() == cnode) {
214		LOCAL_HUB_S(PI_RT_EN_A, 1);
215		LOCAL_HUB_S(PI_RT_EN_B, 1);
216		LOCAL_HUB_S(PI_PROF_EN_A, 0);
217		LOCAL_HUB_S(PI_PROF_EN_B, 0);
218		LOCAL_HUB_S(PI_RT_COUNT, 0);
219		LOCAL_HUB_S(PI_RT_PEND_A, 0);
220		LOCAL_HUB_S(PI_RT_PEND_B, 0);
221	}
222}
223
224static int __init sgi_ip27_rtc_devinit(void)
225{
226	struct resource res;
227
228	memset(&res, 0, sizeof(res));
229	res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
230			      IOC3_BYTEBUS_DEV0);
231	res.end = res.start + 32767;
232	res.flags = IORESOURCE_MEM;
233
234	return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
235						      &res, 1));
236}
237
238/*
239 * kludge make this a device_initcall after ioc3 resource conflicts
240 * are resolved
241 */
242late_initcall(sgi_ip27_rtc_devinit);
243