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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/mips/sgi-ip27/ip27-timer.c
2 * Copytight (C) 1999, 2000, 05, 06 Ralf Baechle (ralf@linux-mips.org)
3 * Copytight (C) 1999, 2000 Silicon Graphics, Inc.
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/time.h>
13 #include <linux/timex.h>
17 #include <asm/pgtable.h>
18 #include <asm/sgialib.h>
19 #include <asm/sn/ioc3.h>
20 #include <asm/m48t35.h>
21 #include <asm/sn/klconfig.h>
22 #include <asm/sn/arch.h>
23 #include <asm/sn/addrs.h>
24 #include <asm/sn/sn_private.h>
25 #include <asm/sn/sn0/ip27.h>
26 #include <asm/sn/sn0/hub.h>
29 * This is a hack; we really need to figure these values out dynamically
31 * Since 800 ns works very well with various HUB frequencies, such as
32 * 360, 380, 390 and 400 MHZ, we use 800 ns rtc cycle time.
34 * Ralf: which clock rate is used to feed the counter?
36 #define NSEC_PER_CYCLE 800
37 #define CYCLES_PER_SEC (NSEC_PER_SEC/NSEC_PER_CYCLE)
38 #define CYCLES_PER_JIFFY (CYCLES_PER_SEC/HZ)
40 #define TICK_SIZE (tick_nsec / 1000)
42 static unsigned long ct_cur
[NR_CPUS
]; /* What counter should be at next timer irq */
43 static long last_rtc_update
; /* Last time the rtc clock got updated */
46 static int set_rtc_mmss(unsigned long nowtime
)
49 int real_seconds
, real_minutes
, cmos_minutes
;
50 struct m48t35_rtc
*rtc
;
54 rtc
= (struct m48t35_rtc
*)(KL_CONFIG_CH_CONS_INFO(nid
)->memory_base
+
57 rtc
->control
|= M48T35_RTC_READ
;
58 cmos_minutes
= BCD2BIN(rtc
->min
);
59 rtc
->control
&= ~M48T35_RTC_READ
;
62 * Since we're only adjusting minutes and seconds, don't interfere with
63 * hour overflow. This avoids messing with unknown time zones but
64 * requires your RTC not to be off by more than 15 minutes
66 real_seconds
= nowtime
% 60;
67 real_minutes
= nowtime
/ 60;
68 if (((abs(real_minutes
- cmos_minutes
) + 15)/30) & 1)
69 real_minutes
+= 30; /* correct for half hour time zone */
72 if (abs(real_minutes
- cmos_minutes
) < 30) {
73 real_seconds
= BIN2BCD(real_seconds
);
74 real_minutes
= BIN2BCD(real_minutes
);
75 rtc
->control
|= M48T35_RTC_SET
;
76 rtc
->sec
= real_seconds
;
77 rtc
->min
= real_minutes
;
78 rtc
->control
&= ~M48T35_RTC_SET
;
81 "set_rtc_mmss: can't update from %d to %d\n",
82 cmos_minutes
, real_minutes
);
90 static unsigned int rt_timer_irq
;
92 void ip27_rt_timer_interrupt(void)
94 int cpu
= smp_processor_id();
95 int cpuA
= cputoslice(cpu
) == 0;
96 unsigned int irq
= rt_timer_irq
;
99 write_seqlock(&xtime_lock
);
102 LOCAL_HUB_S(cpuA
? PI_RT_PEND_A
: PI_RT_PEND_B
, 0); /* Ack */
103 ct_cur
[cpu
] += CYCLES_PER_JIFFY
;
104 LOCAL_HUB_S(cpuA
? PI_RT_COMPARE_A
: PI_RT_COMPARE_B
, ct_cur
[cpu
]);
106 if (LOCAL_HUB_L(PI_RT_COUNT
) >= ct_cur
[cpu
])
109 kstat_this_cpu
.irqs
[irq
]++; /* kstat only for bootcpu? */
114 update_process_times(user_mode(get_irq_regs()));
117 * If we have an externally synchronized Linux clock, then update
118 * RTC clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
119 * called as close as possible to when a second starts.
122 xtime
.tv_sec
> last_rtc_update
+ 660 &&
123 (xtime
.tv_nsec
/ 1000) >= 500000 - ((unsigned) TICK_SIZE
) / 2 &&
124 (xtime
.tv_nsec
/ 1000) <= 500000 + ((unsigned) TICK_SIZE
) / 2) {
125 if (rtc_mips_set_time(xtime
.tv_sec
) == 0) {
126 last_rtc_update
= xtime
.tv_sec
;
128 last_rtc_update
= xtime
.tv_sec
- 600;
129 /* do it again in 60 s */
133 write_sequnlock(&xtime_lock
);
137 /* Includes for ioc3_init(). */
138 #include <asm/sn/types.h>
139 #include <asm/sn/sn0/addrs.h>
140 #include <asm/sn/sn0/hubni.h>
141 #include <asm/sn/sn0/hubio.h>
142 #include <asm/pci/bridge.h>
144 static __init
unsigned long get_m48t35_time(void)
146 unsigned int year
, month
, date
, hour
, min
, sec
;
147 struct m48t35_rtc
*rtc
;
151 rtc
= (struct m48t35_rtc
*)(KL_CONFIG_CH_CONS_INFO(nid
)->memory_base
+
154 rtc
->control
|= M48T35_RTC_READ
;
161 rtc
->control
&= ~M48T35_RTC_READ
;
165 hour
= BCD2BIN(hour
);
166 date
= BCD2BIN(date
);
167 month
= BCD2BIN(month
);
168 year
= BCD2BIN(year
);
172 return mktime(year
, month
, date
, hour
, min
, sec
);
175 static unsigned int startup_rt_irq(unsigned int irq
)
180 static void shutdown_rt_irq(unsigned int irq
)
184 static void enable_rt_irq(unsigned int irq
)
188 static void disable_rt_irq(unsigned int irq
)
192 static void mask_and_ack_rt(unsigned int irq
)
196 static void end_rt_irq(unsigned int irq
)
200 static struct irq_chip rt_irq_type
= {
201 .typename
= "SN HUB RT timer",
202 .startup
= startup_rt_irq
,
203 .shutdown
= shutdown_rt_irq
,
204 .enable
= enable_rt_irq
,
205 .disable
= disable_rt_irq
,
206 .ack
= mask_and_ack_rt
,
210 static struct irqaction rt_irqaction
= {
211 .handler
= ip27_rt_timer_interrupt
,
212 .flags
= IRQF_DISABLED
,
213 .mask
= CPU_MASK_NONE
,
217 void __init
plat_timer_setup(struct irqaction
*irq
)
219 int irqno
= allocate_irqno();
222 panic("Can't allocate interrupt number for timer interrupt");
224 irq_desc
[irqno
].status
= IRQ_DISABLED
;
225 irq_desc
[irqno
].action
= NULL
;
226 irq_desc
[irqno
].depth
= 1;
227 irq_desc
[irqno
].chip
= &rt_irq_type
;
229 /* over-write the handler, we use our own way */
230 irq
->handler
= no_action
;
232 /* setup irqaction */
233 irq_desc
[irqno
].status
|= IRQ_PER_CPU
;
235 rt_timer_irq
= irqno
;
237 * Only needed to get /proc/interrupt to display timer irq stats
239 setup_irq(irqno
, &rt_irqaction
);
242 static unsigned int ip27_hpt_read(void)
244 return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT
);
247 void __init
ip27_time_init(void)
249 mips_hpt_read
= ip27_hpt_read
;
250 mips_hpt_frequency
= CYCLES_PER_SEC
;
251 xtime
.tv_sec
= get_m48t35_time();
255 void __init
cpu_time_init(void)
261 /* Don't use ARCS. ARCS is fragile. Klconfig is simple and sane. */
262 board
= find_lboard(KL_CONFIG_INFO(get_nasid()), KLTYPE_IP27
);
264 panic("Can't find board info for myself.");
266 cpuid
= LOCAL_HUB_L(PI_CPU_NUM
) ? IP27_CPU0_INDEX
: IP27_CPU1_INDEX
;
267 cpu
= (klcpu_t
*) KLCF_COMP(board
, cpuid
);
269 panic("No information about myself?");
271 printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu
->cpu_speed
);
273 set_c0_status(SRB_TIMOCLK
);
276 void __init
hub_rtc_init(cnodeid_t cnode
)
279 * We only need to initialize the current node.
280 * If this is not the current node then it is a cpuless
281 * node and timeouts will not happen there.
283 if (get_compact_nodeid() == cnode
) {
284 int cpu
= smp_processor_id();
285 LOCAL_HUB_S(PI_RT_EN_A
, 1);
286 LOCAL_HUB_S(PI_RT_EN_B
, 1);
287 LOCAL_HUB_S(PI_PROF_EN_A
, 0);
288 LOCAL_HUB_S(PI_PROF_EN_B
, 0);
289 ct_cur
[cpu
] = CYCLES_PER_JIFFY
;
290 LOCAL_HUB_S(PI_RT_COMPARE_A
, ct_cur
[cpu
]);
291 LOCAL_HUB_S(PI_RT_COUNT
, 0);
292 LOCAL_HUB_S(PI_RT_PEND_A
, 0);
293 LOCAL_HUB_S(PI_RT_COMPARE_B
, ct_cur
[cpu
]);
294 LOCAL_HUB_S(PI_RT_COUNT
, 0);
295 LOCAL_HUB_S(PI_RT_PEND_B
, 0);