1 /*
2 * Copytight (C) 1999, 2000, 2002 Ralf Baechle (ralf@gnu.org)
3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
4 */
5 #include <linux/config.h>
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/interrupt.h>
10 #include <linux/kernel_stat.h>
11 #include <linux/param.h>
12 #include <linux/timex.h>
13 #include <linux/mm.h>
14
15 #include <asm/time.h>
16 #include <asm/pgtable.h>
17 #include <asm/sgialib.h>
18 #include <asm/sn/ioc3.h>
19 #include <asm/m48t35.h>
20 #include <asm/sn/klconfig.h>
21 #include <asm/sn/arch.h>
22 #include <asm/sn/addrs.h>
23 #include <asm/sn/sn_private.h>
24 #include <asm/sn/sn0/ip27.h>
25 #include <asm/sn/sn0/hub.h>
26
27 /*
28 * This is a hack; we really need to figure these values out dynamically
29 *
30 * Since 800 ns works very well with various HUB frequencies, such as
31 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
32 *
33 * Ralf: which clock rate is used to feed the counter?
34 */
35 #define NSEC_PER_CYCLE 800
36 #define NSEC_PER_SEC 1000000000
37 #define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE)
38 #define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ)
39
40 static unsigned long ct_cur[NR_CPUS]; /* What counter should be at next timer irq */
41 static long last_rtc_update; /* Last time the rtc clock got updated */
42
43 extern rwlock_t xtime_lock;
44 extern volatile unsigned long wall_jiffies;
45
46
set_rtc_mmss(unsigned long nowtime)47 static int set_rtc_mmss(unsigned long nowtime)
48 {
49 int retval = 0;
50 int real_seconds, real_minutes, cmos_minutes;
51 struct m48t35_rtc *rtc;
52 nasid_t nid;
53
54 rtc = (struct m48t35_rtc *)
55 (KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + IOC3_BYTEBUS_DEV0);
56
57 spin_lock(&rtc_lock);
58 rtc->control |= M48T35_RTC_READ;
59 cmos_minutes = rtc->min;
60 BCD_TO_BIN(cmos_minutes);
61 rtc->control &= ~M48T35_RTC_READ;
62
63 /*
64 * Since we're only adjusting minutes and seconds, don't interfere with
65 * hour overflow. This avoids messing with unknown time zones but
66 * requires your RTC not to be off by more than 15 minutes
67 */
68 real_seconds = nowtime % 60;
69 real_minutes = nowtime / 60;
70 if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
71 real_minutes += 30; /* correct for half hour time zone */
72 real_minutes %= 60;
73
74 if (abs(real_minutes - cmos_minutes) < 30) {
75 BIN_TO_BCD(real_seconds);
76 BIN_TO_BCD(real_minutes);
77 rtc->control |= M48T35_RTC_SET;
78 rtc->sec = real_seconds;
79 rtc->min = real_minutes;
80 rtc->control &= ~M48T35_RTC_SET;
81 } else {
82 printk(KERN_WARNING
83 "set_rtc_mmss: can't update from %d to %d\n",
84 cmos_minutes, real_minutes);
85 retval = -1;
86 }
87 spin_unlock(&rtc_lock);
88
89 return retval;
90 }
91
92 #define IP27_TIMER_IRQ 9 /* XXX Assign number */
93
rt_timer_interrupt(struct pt_regs * regs)94 void rt_timer_interrupt(struct pt_regs *regs)
95 {
96 int cpu = smp_processor_id();
97 int cpuA = ((cputoslice(cpu)) == 0);
98 int irq = IP27_TIMER_IRQ;
99
100 irq_enter(cpu, irq);
101 write_lock(&xtime_lock);
102
103 again:
104 LOCAL_HUB_S(cpuA ? PI_RT_PEND_A : PI_RT_PEND_B, 0); /* Ack */
105 ct_cur[cpu] += CYCLES_PER_JIFFY;
106 LOCAL_HUB_S(cpuA ? PI_RT_COMPARE_A : PI_RT_COMPARE_B, ct_cur[cpu]);
107
108 if (LOCAL_HUB_L(PI_RT_COUNT) >= ct_cur[cpu])
109 goto again;
110
111 kstat.irqs[cpu][irq]++; /* kstat only for bootcpu? */
112
113 if (cpu == 0)
114 do_timer(regs);
115
116 #ifdef CONFIG_SMP
117 update_process_times(user_mode(regs));
118 #endif /* CONFIG_SMP */
119
120 /*
121 * If we have an externally synchronized Linux clock, then update
122 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
123 * called as close as possible to when a second starts.
124 */
125 if ((time_status & STA_UNSYNC) == 0 &&
126 xtime.tv_sec > last_rtc_update + 660) {
127 if (xtime.tv_usec >= 1000000 - ((unsigned) tick) / 2) {
128 if (set_rtc_mmss(xtime.tv_sec + 1) == 0)
129 last_rtc_update = xtime.tv_sec;
130 else
131 last_rtc_update = xtime.tv_sec - 600;
132 } else if (xtime.tv_usec <= ((unsigned) tick) / 2) {
133 if (set_rtc_mmss(xtime.tv_sec) == 0)
134 last_rtc_update = xtime.tv_sec;
135 else
136 last_rtc_update = xtime.tv_sec - 600;
137 }
138 }
139
140 write_unlock(&xtime_lock);
141 irq_exit(cpu, irq);
142
143 if (softirq_pending(cpu))
144 do_softirq();
145 }
146
ip27_do_gettimeoffset(void)147 unsigned long ip27_do_gettimeoffset(void)
148 {
149 unsigned long ct_cur1;
150 ct_cur1 = REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT) + CYCLES_PER_JIFFY;
151 return (ct_cur1 - ct_cur[0]) * NSEC_PER_CYCLE / 1000;
152 }
153
154 /* Includes for ioc3_init(). */
155 #include <asm/sn/types.h>
156 #include <asm/sn/sn0/addrs.h>
157 #include <asm/sn/sn0/hubni.h>
158 #include <asm/sn/sn0/hubio.h>
159 #include <asm/pci/bridge.h>
160
get_m48t35_time(void)161 static __init unsigned long get_m48t35_time(void)
162 {
163 unsigned int year, month, date, hour, min, sec;
164 struct m48t35_rtc *rtc;
165 nasid_t nid;
166
167 nid = get_nasid();
168 rtc = (struct m48t35_rtc *)(KL_CONFIG_CH_CONS_INFO(nid)->memory_base +
169 IOC3_BYTEBUS_DEV0);
170
171 spin_lock(&rtc_lock);
172 rtc->control |= M48T35_RTC_READ;
173 sec = rtc->sec;
174 min = rtc->min;
175 hour = rtc->hour;
176 date = rtc->date;
177 month = rtc->month;
178 year = rtc->year;
179 rtc->control &= ~M48T35_RTC_READ;
180 spin_unlock(&rtc_lock);
181
182 BCD_TO_BIN(sec);
183 BCD_TO_BIN(min);
184 BCD_TO_BIN(hour);
185 BCD_TO_BIN(date);
186 BCD_TO_BIN(month);
187 BCD_TO_BIN(year);
188
189 year += 1970;
190
191 return mktime(year, month, date, hour, min, sec);
192 }
193
ip27_timer_setup(struct irqaction * irq)194 static void ip27_timer_setup(struct irqaction *irq)
195 {
196 /* over-write the handler, we use our own way */
197 irq->handler = no_action;
198
199 /* setup irqaction */
200 // setup_irq(IP27_TIMER_IRQ, irq); /* XXX Can't do this yet. */
201 }
202
ip27_time_init(void)203 void __init ip27_time_init(void)
204 {
205 xtime.tv_sec = get_m48t35_time();
206 xtime.tv_usec = 0;
207
208 do_gettimeoffset = ip27_do_gettimeoffset;
209
210 // board_time_init = ip27_time_init;
211 board_timer_setup = ip27_timer_setup;
212 }
213
cpu_time_init(void)214 void __init cpu_time_init(void)
215 {
216 lboard_t *board;
217 klcpu_t *cpu;
218 int cpuid;
219
220 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */
221 board = find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27);
222 if (!board)
223 panic("Can't find board info for myself.");
224
225 cpuid = LOCAL_HUB_L(PI_CPU_NUM) ? IP27_CPU0_INDEX : IP27_CPU1_INDEX;
226 cpu = (klcpu_t *) KLCF_COMP(board, cpuid);
227 if (!cpu)
228 panic("No information about myself?");
229
230 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
231
232 set_c0_status(SRB_TIMOCLK);
233 }
234
hub_rtc_init(cnodeid_t cnode)235 void __init hub_rtc_init(cnodeid_t cnode)
236 {
237 /*
238 * We only need to initialize the current node.
239 * If this is not the current node then it is a cpuless
240 * node and timeouts will not happen there.
241 */
242 if (get_compact_nodeid() == cnode) {
243 int cpu = smp_processor_id();
244 LOCAL_HUB_S(PI_RT_EN_A, 1);
245 LOCAL_HUB_S(PI_RT_EN_B, 1);
246 LOCAL_HUB_S(PI_PROF_EN_A, 0);
247 LOCAL_HUB_S(PI_PROF_EN_B, 0);
248 ct_cur[cpu] = CYCLES_PER_JIFFY;
249 LOCAL_HUB_S(PI_RT_COMPARE_A, ct_cur[cpu]);
250 LOCAL_HUB_S(PI_RT_COUNT, 0);
251 LOCAL_HUB_S(PI_RT_PEND_A, 0);
252 LOCAL_HUB_S(PI_RT_COMPARE_B, ct_cur[cpu]);
253 LOCAL_HUB_S(PI_RT_COUNT, 0);
254 LOCAL_HUB_S(PI_RT_PEND_B, 0);
255 }
256 }
257