xref: /openbmc/linux/arch/sparc/kernel/time_32.c (revision d7a3d85e) 
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/mc146818rtc.h>
40 #include <asm/oplib.h>
41 #include <asm/timex.h>
42 #include <asm/timer.h>
43 #include <asm/irq.h>
44 #include <asm/io.h>
45 #include <asm/idprom.h>
46 #include <asm/page.h>
47 #include <asm/pcic.h>
48 #include <asm/irq_regs.h>
49 #include <asm/setup.h>
50 
51 #include "kernel.h"
52 #include "irq.h"
53 
54 static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
55 static __volatile__ u64 timer_cs_internal_counter = 0;
56 static char timer_cs_enabled = 0;
57 
58 static struct clock_event_device timer_ce;
59 static char timer_ce_enabled = 0;
60 
61 #ifdef CONFIG_SMP
62 DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
63 #endif
64 
65 DEFINE_SPINLOCK(rtc_lock);
66 EXPORT_SYMBOL(rtc_lock);
67 
68 static int set_rtc_mmss(unsigned long);
69 
70 unsigned long profile_pc(struct pt_regs *regs)
71 {
72 	extern char __copy_user_begin[], __copy_user_end[];
73 	extern char __bzero_begin[], __bzero_end[];
74 
75 	unsigned long pc = regs->pc;
76 
77 	if (in_lock_functions(pc) ||
78 	    (pc >= (unsigned long) __copy_user_begin &&
79 	     pc < (unsigned long) __copy_user_end) ||
80 	    (pc >= (unsigned long) __bzero_begin &&
81 	     pc < (unsigned long) __bzero_end))
82 		pc = regs->u_regs[UREG_RETPC];
83 	return pc;
84 }
85 
86 EXPORT_SYMBOL(profile_pc);
87 
88 volatile u32 __iomem *master_l10_counter;
89 
90 int update_persistent_clock(struct timespec now)
91 {
92 	return set_rtc_mmss(now.tv_sec);
93 }
94 
95 irqreturn_t notrace timer_interrupt(int dummy, void *dev_id)
96 {
97 	if (timer_cs_enabled) {
98 		write_seqlock(&timer_cs_lock);
99 		timer_cs_internal_counter++;
100 		sparc_config.clear_clock_irq();
101 		write_sequnlock(&timer_cs_lock);
102 	} else {
103 		sparc_config.clear_clock_irq();
104 	}
105 
106 	if (timer_ce_enabled)
107 		timer_ce.event_handler(&timer_ce);
108 
109 	return IRQ_HANDLED;
110 }
111 
112 static void timer_ce_set_mode(enum clock_event_mode mode,
113 			      struct clock_event_device *evt)
114 {
115 	switch (mode) {
116 		case CLOCK_EVT_MODE_PERIODIC:
117 		case CLOCK_EVT_MODE_RESUME:
118 			timer_ce_enabled = 1;
119 			break;
120 		case CLOCK_EVT_MODE_SHUTDOWN:
121 			timer_ce_enabled = 0;
122 			break;
123 		default:
124 			break;
125 	}
126 	smp_mb();
127 }
128 
129 static __init void setup_timer_ce(void)
130 {
131 	struct clock_event_device *ce = &timer_ce;
132 
133 	BUG_ON(smp_processor_id() != boot_cpu_id);
134 
135 	ce->name     = "timer_ce";
136 	ce->rating   = 100;
137 	ce->features = CLOCK_EVT_FEAT_PERIODIC;
138 	ce->set_mode = timer_ce_set_mode;
139 	ce->cpumask  = cpu_possible_mask;
140 	ce->shift    = 32;
141 	ce->mult     = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
142 	                      ce->shift);
143 	clockevents_register_device(ce);
144 }
145 
146 static unsigned int sbus_cycles_offset(void)
147 {
148 	u32 val, offset;
149 
150 	val = sbus_readl(master_l10_counter);
151 	offset = (val >> TIMER_VALUE_SHIFT) & TIMER_VALUE_MASK;
152 
153 	/* Limit hit? */
154 	if (val & TIMER_LIMIT_BIT)
155 		offset += sparc_config.cs_period;
156 
157 	return offset;
158 }
159 
160 static cycle_t timer_cs_read(struct clocksource *cs)
161 {
162 	unsigned int seq, offset;
163 	u64 cycles;
164 
165 	do {
166 		seq = read_seqbegin(&timer_cs_lock);
167 
168 		cycles = timer_cs_internal_counter;
169 		offset = sparc_config.get_cycles_offset();
170 	} while (read_seqretry(&timer_cs_lock, seq));
171 
172 	/* Count absolute cycles */
173 	cycles *= sparc_config.cs_period;
174 	cycles += offset;
175 
176 	return cycles;
177 }
178 
179 static struct clocksource timer_cs = {
180 	.name	= "timer_cs",
181 	.rating	= 100,
182 	.read	= timer_cs_read,
183 	.mask	= CLOCKSOURCE_MASK(64),
184 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
185 };
186 
187 static __init int setup_timer_cs(void)
188 {
189 	timer_cs_enabled = 1;
190 	return clocksource_register_hz(&timer_cs, sparc_config.clock_rate);
191 }
192 
193 #ifdef CONFIG_SMP
194 static void percpu_ce_setup(enum clock_event_mode mode,
195 			struct clock_event_device *evt)
196 {
197 	int cpu = cpumask_first(evt->cpumask);
198 
199 	switch (mode) {
200 		case CLOCK_EVT_MODE_PERIODIC:
201 			sparc_config.load_profile_irq(cpu,
202 						      SBUS_CLOCK_RATE / HZ);
203 			break;
204 		case CLOCK_EVT_MODE_ONESHOT:
205 		case CLOCK_EVT_MODE_SHUTDOWN:
206 		case CLOCK_EVT_MODE_UNUSED:
207 			sparc_config.load_profile_irq(cpu, 0);
208 			break;
209 		default:
210 			break;
211 	}
212 }
213 
214 static int percpu_ce_set_next_event(unsigned long delta,
215 				    struct clock_event_device *evt)
216 {
217 	int cpu = cpumask_first(evt->cpumask);
218 	unsigned int next = (unsigned int)delta;
219 
220 	sparc_config.load_profile_irq(cpu, next);
221 	return 0;
222 }
223 
224 void register_percpu_ce(int cpu)
225 {
226 	struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
227 	unsigned int features = CLOCK_EVT_FEAT_PERIODIC;
228 
229 	if (sparc_config.features & FEAT_L14_ONESHOT)
230 		features |= CLOCK_EVT_FEAT_ONESHOT;
231 
232 	ce->name           = "percpu_ce";
233 	ce->rating         = 200;
234 	ce->features       = features;
235 	ce->set_mode       = percpu_ce_setup;
236 	ce->set_next_event = percpu_ce_set_next_event;
237 	ce->cpumask        = cpumask_of(cpu);
238 	ce->shift          = 32;
239 	ce->mult           = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
240 	                            ce->shift);
241 	ce->max_delta_ns   = clockevent_delta2ns(sparc_config.clock_rate, ce);
242 	ce->min_delta_ns   = clockevent_delta2ns(100, ce);
243 
244 	clockevents_register_device(ce);
245 }
246 #endif
247 
248 static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
249 {
250 	struct platform_device *pdev = to_platform_device(dev);
251 	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
252 
253 	return readb(pdata->ioaddr + ofs);
254 }
255 
256 static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
257 {
258 	struct platform_device *pdev = to_platform_device(dev);
259 	struct m48t59_plat_data *pdata = pdev->dev.platform_data;
260 
261 	writeb(val, pdata->ioaddr + ofs);
262 }
263 
264 static struct m48t59_plat_data m48t59_data = {
265 	.read_byte = mostek_read_byte,
266 	.write_byte = mostek_write_byte,
267 };
268 
269 /* resource is set at runtime */
270 static struct platform_device m48t59_rtc = {
271 	.name		= "rtc-m48t59",
272 	.id		= 0,
273 	.num_resources	= 1,
274 	.dev	= {
275 		.platform_data = &m48t59_data,
276 	},
277 };
278 
279 static int clock_probe(struct platform_device *op)
280 {
281 	struct device_node *dp = op->dev.of_node;
282 	const char *model = of_get_property(dp, "model", NULL);
283 
284 	if (!model)
285 		return -ENODEV;
286 
287 	/* Only the primary RTC has an address property */
288 	if (!of_find_property(dp, "address", NULL))
289 		return -ENODEV;
290 
291 	m48t59_rtc.resource = &op->resource[0];
292 	if (!strcmp(model, "mk48t02")) {
293 		/* Map the clock register io area read-only */
294 		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
295 						2048, "rtc-m48t59");
296 		m48t59_data.type = M48T59RTC_TYPE_M48T02;
297 	} else if (!strcmp(model, "mk48t08")) {
298 		m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
299 						8192, "rtc-m48t59");
300 		m48t59_data.type = M48T59RTC_TYPE_M48T08;
301 	} else
302 		return -ENODEV;
303 
304 	if (platform_device_register(&m48t59_rtc) < 0)
305 		printk(KERN_ERR "Registering RTC device failed\n");
306 
307 	return 0;
308 }
309 
310 static struct of_device_id clock_match[] = {
311 	{
312 		.name = "eeprom",
313 	},
314 	{},
315 };
316 
317 static struct platform_driver clock_driver = {
318 	.probe		= clock_probe,
319 	.driver = {
320 		.name = "rtc",
321 		.of_match_table = clock_match,
322 	},
323 };
324 
325 
326 /* Probe for the mostek real time clock chip. */
327 static int __init clock_init(void)
328 {
329 	return platform_driver_register(&clock_driver);
330 }
331 /* Must be after subsys_initcall() so that busses are probed.  Must
332  * be before device_initcall() because things like the RTC driver
333  * need to see the clock registers.
334  */
335 fs_initcall(clock_init);
336 
337 static void __init sparc32_late_time_init(void)
338 {
339 	if (sparc_config.features & FEAT_L10_CLOCKEVENT)
340 		setup_timer_ce();
341 	if (sparc_config.features & FEAT_L10_CLOCKSOURCE)
342 		setup_timer_cs();
343 #ifdef CONFIG_SMP
344 	register_percpu_ce(smp_processor_id());
345 #endif
346 }
347 
348 static void __init sbus_time_init(void)
349 {
350 	sparc_config.get_cycles_offset = sbus_cycles_offset;
351 	sparc_config.init_timers();
352 }
353 
354 void __init time_init(void)
355 {
356 	sparc_config.features = 0;
357 	late_time_init = sparc32_late_time_init;
358 
359 	if (pcic_present())
360 		pci_time_init();
361 	else
362 		sbus_time_init();
363 }
364 
365 
366 static int set_rtc_mmss(unsigned long secs)
367 {
368 	struct rtc_device *rtc = rtc_class_open("rtc0");
369 	int err = -1;
370 
371 	if (rtc) {
372 		err = rtc_set_mmss(rtc, secs);
373 		rtc_class_close(rtc);
374 	}
375 
376 	return err;
377 }
378