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/interrupt.h>
11 #include <linux/kernel_stat.h>
12 #include <linux/param.h>
13 #include <linux/smp.h>
14 #include <linux/time.h>
15 #include <linux/timex.h>
16 #include <linux/mm.h>
17 #include <linux/platform_device.h>
18
19 #include <asm/time.h>
20 #include <asm/pgtable.h>
21 #include <asm/sgialib.h>
22 #include <asm/sn/ioc3.h>
23 #include <asm/sn/klconfig.h>
24 #include <asm/sn/arch.h>
25 #include <asm/sn/addrs.h>
26 #include <asm/sn/sn_private.h>
27 #include <asm/sn/sn0/ip27.h>
28 #include <asm/sn/sn0/hub.h>
29
30 #define TICK_SIZE (tick_nsec / 1000)
31
32 /* Includes for ioc3_init(). */
33 #include <asm/sn/types.h>
34 #include <asm/sn/sn0/addrs.h>
35 #include <asm/sn/sn0/hubni.h>
36 #include <asm/sn/sn0/hubio.h>
37 #include <asm/pci/bridge.h>
38
enable_rt_irq(struct irq_data * d)39 static void enable_rt_irq(struct irq_data *d)
40 {
41 }
42
disable_rt_irq(struct irq_data * d)43 static void disable_rt_irq(struct irq_data *d)
44 {
45 }
46
47 static struct irq_chip rt_irq_type = {
48 .name = "SN HUB RT timer",
49 .irq_mask = disable_rt_irq,
50 .irq_unmask = enable_rt_irq,
51 };
52
rt_next_event(unsigned long delta,struct clock_event_device * evt)53 static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
54 {
55 unsigned int cpu = smp_processor_id();
56 int slice = cputoslice(cpu);
57 unsigned long cnt;
58
59 cnt = LOCAL_HUB_L(PI_RT_COUNT);
60 cnt += delta;
61 LOCAL_HUB_S(PI_RT_COMPARE_A + PI_COUNT_OFFSET * slice, cnt);
62
63 return LOCAL_HUB_L(PI_RT_COUNT) >= cnt ? -ETIME : 0;
64 }
65
rt_set_mode(enum clock_event_mode mode,struct clock_event_device * evt)66 static void rt_set_mode(enum clock_event_mode mode,
67 struct clock_event_device *evt)
68 {
69 switch (mode) {
70 case CLOCK_EVT_MODE_ONESHOT:
71 /* The only mode supported */
72 break;
73
74 case CLOCK_EVT_MODE_PERIODIC:
75 case CLOCK_EVT_MODE_UNUSED:
76 case CLOCK_EVT_MODE_SHUTDOWN:
77 case CLOCK_EVT_MODE_RESUME:
78 /* Nothing to do */
79 break;
80 }
81 }
82
83 int rt_timer_irq;
84
85 static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
86 static DEFINE_PER_CPU(char [11], hub_rt_name);
87
hub_rt_counter_handler(int irq,void * dev_id)88 static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
89 {
90 unsigned int cpu = smp_processor_id();
91 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
92 int slice = cputoslice(cpu);
93
94 /*
95 * Ack
96 */
97 LOCAL_HUB_S(PI_RT_PEND_A + PI_COUNT_OFFSET * slice, 0);
98 cd->event_handler(cd);
99
100 return IRQ_HANDLED;
101 }
102
103 struct irqaction hub_rt_irqaction = {
104 .handler = hub_rt_counter_handler,
105 .flags = IRQF_DISABLED | IRQF_PERCPU | IRQF_TIMER,
106 .name = "hub-rt",
107 };
108
109 /*
110 * This is a hack; we really need to figure these values out dynamically
111 *
112 * Since 800 ns works very well with various HUB frequencies, such as
113 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
114 *
115 * Ralf: which clock rate is used to feed the counter?
116 */
117 #define NSEC_PER_CYCLE 800
118 #define CYCLES_PER_SEC (NSEC_PER_SEC / NSEC_PER_CYCLE)
119
hub_rt_clock_event_init(void)120 void __cpuinit hub_rt_clock_event_init(void)
121 {
122 unsigned int cpu = smp_processor_id();
123 struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
124 unsigned char *name = per_cpu(hub_rt_name, cpu);
125 int irq = rt_timer_irq;
126
127 sprintf(name, "hub-rt %d", cpu);
128 cd->name = name;
129 cd->features = CLOCK_EVT_FEAT_ONESHOT;
130 clockevent_set_clock(cd, CYCLES_PER_SEC);
131 cd->max_delta_ns = clockevent_delta2ns(0xfffffffffffff, cd);
132 cd->min_delta_ns = clockevent_delta2ns(0x300, cd);
133 cd->rating = 200;
134 cd->irq = irq;
135 cd->cpumask = cpumask_of(cpu);
136 cd->set_next_event = rt_next_event;
137 cd->set_mode = rt_set_mode;
138 clockevents_register_device(cd);
139 }
140
hub_rt_clock_event_global_init(void)141 static void __init hub_rt_clock_event_global_init(void)
142 {
143 int irq;
144
145 do {
146 smp_wmb();
147 irq = rt_timer_irq;
148 if (irq)
149 break;
150
151 irq = allocate_irqno();
152 if (irq < 0)
153 panic("Allocation of irq number for timer failed");
154 } while (xchg(&rt_timer_irq, irq));
155
156 irq_set_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
157 setup_irq(irq, &hub_rt_irqaction);
158 }
159
hub_rt_read(struct clocksource * cs)160 static cycle_t hub_rt_read(struct clocksource *cs)
161 {
162 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
163 }
164
165 struct clocksource hub_rt_clocksource = {
166 .name = "HUB-RT",
167 .rating = 200,
168 .read = hub_rt_read,
169 .mask = CLOCKSOURCE_MASK(52),
170 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
171 };
172
hub_rt_clocksource_init(void)173 static void __init hub_rt_clocksource_init(void)
174 {
175 struct clocksource *cs = &hub_rt_clocksource;
176
177 clocksource_set_clock(cs, CYCLES_PER_SEC);
178 clocksource_register(cs);
179 }
180
plat_time_init(void)181 void __init plat_time_init(void)
182 {
183 hub_rt_clocksource_init();
184 hub_rt_clock_event_global_init();
185 hub_rt_clock_event_init();
186 }
187
cpu_time_init(void)188 void __cpuinit cpu_time_init(void)
189 {
190 lboard_t *board;
191 klcpu_t *cpu;
192 int cpuid;
193
194 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */
195 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
196 if (!board)
197 panic("Can't find board info for myself.");
198
199 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
200 cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
201 if (!cpu)
202 panic("No information about myself?");
203
204 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
205
206 set_c0_status(SRB_TIMOCLK);
207 }
208
hub_rtc_init(cnodeid_t cnode)209 void __cpuinit hub_rtc_init(cnodeid_t cnode)
210 {
211
212 /*
213 * We only need to initialize the current node.
214 * If this is not the current node then it is a cpuless
215 * node and timeouts will not happen there.
216 */
217 if (get_compact_nodeid() == cnode) {
218 LOCAL_HUB_S(PI_RT_EN_A, 1);
219 LOCAL_HUB_S(PI_RT_EN_B, 1);
220 LOCAL_HUB_S(PI_PROF_EN_A, 0);
221 LOCAL_HUB_S(PI_PROF_EN_B, 0);
222 LOCAL_HUB_S(PI_RT_COUNT, 0);
223 LOCAL_HUB_S(PI_RT_PEND_A, 0);
224 LOCAL_HUB_S(PI_RT_PEND_B, 0);
225 }
226 }
227
sgi_ip27_rtc_devinit(void)228 static int __init sgi_ip27_rtc_devinit(void)
229 {
230 struct resource res;
231
232 memset(&res, 0, sizeof(res));
233 res.start = XPHYSADDR(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base +
234 IOC3_BYTEBUS_DEV0);
235 res.end = res.start + 32767;
236 res.flags = IORESOURCE_MEM;
237
238 return IS_ERR(platform_device_register_simple("rtc-m48t35", -1,
239 &res, 1));
240 }
241
242 /*
243 * kludge make this a device_initcall after ioc3 resource conflicts
244 * are resolved
245 */
246 late_initcall(sgi_ip27_rtc_devinit);
247