xref: /openbmc/linux/arch/sparc/kernel/time_32.c (revision b34e08d5) 
1 /* linux/arch/sparc/kernel/time.c
2  *
3  * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
4  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
5  *
6  * Chris Davis (cdavis@cois.on.ca) 03/27/1998
7  * Added support for the intersil on the sun4/4200
8  *
9  * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
10  * Support for MicroSPARC-IIep, PCI CPU.
11  *
12  * This file handles the Sparc specific time handling details.
13  *
14  * 1997-09-10	Updated NTP code according to technical memorandum Jan '96
15  *		"A Kernel Model for Precision Timekeeping" by Dave Mills
16  */
17 #include <linux/errno.h>
18 #include <linux/module.h>
19 #include <linux/sched.h>
20 #include <linux/kernel.h>
21 #include <linux/param.h>
22 #include <linux/string.h>
23 #include <linux/mm.h>
24 #include <linux/interrupt.h>
25 #include <linux/time.h>
26 #include <linux/rtc.h>
27 #include <linux/rtc/m48t59.h>
28 #include <linux/timex.h>
29 #include <linux/clocksource.h>
30 #include <linux/clockchips.h>
31 #include <linux/init.h>
32 #include <linux/pci.h>
33 #include <linux/ioport.h>
34 #include <linux/profile.h>
35 #include <linux/of.h>
36 #include <linux/of_device.h>
37 #include <linux/platform_device.h>
38 
39 #include <asm/oplib.h>
40 #include <asm/timex.h>
41 #include <asm/timer.h>
42 #include <asm/irq.h>
43 #include <asm/io.h>
44 #include <asm/idprom.h>
45 #include <asm/page.h>
46 #include <asm/pcic.h>
47 #include <asm/irq_regs.h>
48 #include <asm/setup.h>
49 
50 #include "irq.h"
51 
52 static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
53 static __volatile__ u64 timer_cs_internal_counter = 0;
54 static char timer_cs_enabled = 0;
55 
56 static struct clock_event_device timer_ce;
57 static char timer_ce_enabled = 0;
58 
59 #ifdef CONFIG_SMP
60 DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
61 #endif
62 
63 DEFINE_SPINLOCK(rtc_lock);
64 EXPORT_SYMBOL(rtc_lock);
65 
66 static int set_rtc_mmss(unsigned long);
67 
68 unsigned long profile_pc(struct pt_regs *regs)
69 {
70 	extern char __copy_user_begin[], __copy_user_end[];
71 	extern char __bzero_begin[], __bzero_end[];
72 
73 	unsigned long pc = regs->pc;
74 
75 	if (in_lock_functions(pc) ||
76 	    (pc >= (unsigned long) __copy_user_begin &&
77 	     pc < (unsigned long) __copy_user_end) ||
78 	    (pc >= (unsigned long) __bzero_begin &&
79 	     pc < (unsigned long) __bzero_end))
80 		pc = regs->u_regs[UREG_RETPC];
81 	return pc;
82 }
83 
84 EXPORT_SYMBOL(profile_pc);
85 
86 __volatile__ unsigned int *master_l10_counter;
87 
88 int update_persistent_clock(struct timespec now)
89 {
90 	return set_rtc_mmss(now.tv_sec);
91 }
92 
93 irqreturn_t notrace timer_interrupt(int dummy, void *dev_id)
94 {
95 	if (timer_cs_enabled) {
96 		write_seqlock(&timer_cs_lock);
97 		timer_cs_internal_counter++;
98 		sparc_config.clear_clock_irq();
99 		write_sequnlock(&timer_cs_lock);
100 	} else {
101 		sparc_config.clear_clock_irq();
102 	}
103 
104 	if (timer_ce_enabled)
105 		timer_ce.event_handler(&timer_ce);
106 
107 	return IRQ_HANDLED;
108 }
109 
110 static void timer_ce_set_mode(enum clock_event_mode mode,
111 			      struct clock_event_device *evt)
112 {
113 	switch (mode) {
114 		case CLOCK_EVT_MODE_PERIODIC:
115 		case CLOCK_EVT_MODE_RESUME:
116 			timer_ce_enabled = 1;
117 			break;
118 		case CLOCK_EVT_MODE_SHUTDOWN:
119 			timer_ce_enabled = 0;
120 			break;
121 		default:
122 			break;
123 	}
124 	smp_mb();
125 }
126 
127 static __init void setup_timer_ce(void)
128 {
129 	struct clock_event_device *ce = &timer_ce;
130 
131 	BUG_ON(smp_processor_id() != boot_cpu_id);
132 
133 	ce->name     = "timer_ce";
134 	ce->rating   = 100;
135 	ce->features = CLOCK_EVT_FEAT_PERIODIC;
136 	ce->set_mode = timer_ce_set_mode;
137 	ce->cpumask  = cpu_possible_mask;
138 	ce->shift    = 32;
139 	ce->mult     = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
140 	                      ce->shift);
141 	clockevents_register_device(ce);
142 }
143 
144 static unsigned int sbus_cycles_offset(void)
145 {
146 	unsigned int val, offset;
147 
148 	val = *master_l10_counter;
149 	offset = (val >> TIMER_VALUE_SHIFT) & TIMER_VALUE_MASK;
150 
151 	/* Limit hit? */
152 	if (val & TIMER_LIMIT_BIT)
153 		offset += sparc_config.cs_period;
154 
155 	return offset;
156 }
157 
158 static cycle_t timer_cs_read(struct clocksource *cs)
159 {
160 	unsigned int seq, offset;
161 	u64 cycles;
162 
163 	do {
164 		seq = read_seqbegin(&timer_cs_lock);
165 
166 		cycles = timer_cs_internal_counter;
167 		offset = sparc_config.get_cycles_offset();
168 	} while (read_seqretry(&timer_cs_lock, seq));
169 
170 	/* Count absolute cycles */
171 	cycles *= sparc_config.cs_period;
172 	cycles += offset;
173 
174 	return cycles;
175 }
176 
177 static struct clocksource timer_cs = {
178 	.name	= "timer_cs",
179 	.rating	= 100,
180 	.read	= timer_cs_read,
181 	.mask	= CLOCKSOURCE_MASK(64),
182 	.shift	= 2,
183 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
184 };
185 
186 static __init int setup_timer_cs(void)
187 {
188 	timer_cs_enabled = 1;
189 	timer_cs.mult = clocksource_hz2mult(sparc_config.clock_rate,
190 	                                    timer_cs.shift);
191 
192 	return clocksource_register(&timer_cs);
193 }
194 
195 #ifdef CONFIG_SMP
196 static void percpu_ce_setup(enum clock_event_mode mode,
197 			struct clock_event_device *evt)
198 {
199 	int cpu = __first_cpu(evt->cpumask);
200 
201 	switch (mode) {
202 		case CLOCK_EVT_MODE_PERIODIC:
203 			sparc_config.load_profile_irq(cpu,
204 						      SBUS_CLOCK_RATE / HZ);
205 			break;
206 		case CLOCK_EVT_MODE_ONESHOT:
207 		case CLOCK_EVT_MODE_SHUTDOWN:
208 		case CLOCK_EVT_MODE_UNUSED:
209 			sparc_config.load_profile_irq(cpu, 0);
210 			break;
211 		default:
212 			break;
213 	}
214 }
215 
216 static int percpu_ce_set_next_event(unsigned long delta,
217 				    struct clock_event_device *evt)
218 {
219 	int cpu = __first_cpu(evt->cpumask);
220 	unsigned int next = (unsigned int)delta;
221 
222 	sparc_config.load_profile_irq(cpu, next);
223 	return 0;
224 }
225 
226 void register_percpu_ce(int cpu)
227 {
228 	struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
229 	unsigned int features = CLOCK_EVT_FEAT_PERIODIC;
230 
231 	if (sparc_config.features & FEAT_L14_ONESHOT)
232 		features |= CLOCK_EVT_FEAT_ONESHOT;
233 
234 	ce->name           = "percpu_ce";
235 	ce->rating         = 200;
236 	ce->features       = features;
237 	ce->set_mode       = percpu_ce_setup;
238 	ce->set_next_event = percpu_ce_set_next_event;
239 	ce->cpumask        = cpumask_of(cpu);
240 	ce->shift          = 32;
241 	ce->mult           = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
242 	                            ce->shift);
243 	ce->max_delta_ns   = clockevent_delta2ns(sparc_config.clock_rate, ce);
244 	ce->min_delta_ns   = clockevent_delta2ns(100, ce);
245 
246 	clockevents_register_device(ce);
247 }
248 #endif
249 
250 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
251 {
252 	struct platform_device *pdev = to_platform_device(dev);
253 	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
254 
255 	return readb(pdata->ioaddr + ofs);
256 }
257 
258 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
259 {
260 	struct platform_device *pdev = to_platform_device(dev);
261 	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
262 
263 	writeb(val, pdata->ioaddr + ofs);
264 }
265 
266 static struct m48t59_plat_data m48t59_data = {
267 	.read_byte = mostek_read_byte,
268 	.write_byte = mostek_write_byte,
269 };
270 
271 /* resource is set at runtime */
272 static struct platform_device m48t59_rtc = {
273 	.name		= "rtc-m48t59",
274 	.id		= 0,
275 	.num_resources	= 1,
276 	.dev	= {
277 		.platform_data = &m48t59_data,
278 	},
279 };
280 
281 static int clock_probe(struct platform_device *op)
282 {
283 	struct device_node *dp = op->dev.of_node;
284 	const char *model = of_get_property(dp, "model", NULL);
285 
286 	if (!model)
287 		return -ENODEV;
288 
289 	/* Only the primary RTC has an address property */
290 	if (!of_find_property(dp, "address", NULL))
291 		return -ENODEV;
292 
293 	m48t59_rtc.resource = &op->resource[0];
294 	if (!strcmp(model, "mk48t02")) {
295 		/* Map the clock register io area read-only */
296 		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
297 						2048, "rtc-m48t59");
298 		m48t59_data.type = M48T59RTC_TYPE_M48T02;
299 	} else if (!strcmp(model, "mk48t08")) {
300 		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
301 						8192, "rtc-m48t59");
302 		m48t59_data.type = M48T59RTC_TYPE_M48T08;
303 	} else
304 		return -ENODEV;
305 
306 	if (platform_device_register(&m48t59_rtc) < 0)
307 		printk(KERN_ERR "Registering RTC device failed\n");
308 
309 	return 0;
310 }
311 
312 static struct of_device_id clock_match[] = {
313 	{
314 		.name = "eeprom",
315 	},
316 	{},
317 };
318 
319 static struct platform_driver clock_driver = {
320 	.probe		= clock_probe,
321 	.driver = {
322 		.name = "rtc",
323 		.owner = THIS_MODULE,
324 		.of_match_table = clock_match,
325 	},
326 };
327 
328 
329 /* Probe for the mostek real time clock chip. */
330 static int __init clock_init(void)
331 {
332 	return platform_driver_register(&clock_driver);
333 }
334 /* Must be after subsys_initcall() so that busses are probed.  Must
335  * be before device_initcall() because things like the RTC driver
336  * need to see the clock registers.
337  */
338 fs_initcall(clock_init);
339 
340 static void __init sparc32_late_time_init(void)
341 {
342 	if (sparc_config.features & FEAT_L10_CLOCKEVENT)
343 		setup_timer_ce();
344 	if (sparc_config.features & FEAT_L10_CLOCKSOURCE)
345 		setup_timer_cs();
346 #ifdef CONFIG_SMP
347 	register_percpu_ce(smp_processor_id());
348 #endif
349 }
350 
351 static void __init sbus_time_init(void)
352 {
353 	sparc_config.get_cycles_offset = sbus_cycles_offset;
354 	sparc_config.init_timers();
355 }
356 
357 void __init time_init(void)
358 {
359 	sparc_config.features = 0;
360 	late_time_init = sparc32_late_time_init;
361 
362 	if (pcic_present())
363 		pci_time_init();
364 	else
365 		sbus_time_init();
366 }
367 
368 
369 static int set_rtc_mmss(unsigned long secs)
370 {
371 	struct rtc_device *rtc = rtc_class_open("rtc0");
372 	int err = -1;
373 
374 	if (rtc) {
375 		err = rtc_set_mmss(rtc, secs);
376 		rtc_class_close(rtc);
377 	}
378 
379 	return err;
380 }
381