1/*-
2 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3 * Copyright (C) 1995, 1996 TooLs GmbH.
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. All advertising materials mentioning features or use of this software
15 *    must display the following acknowledgement:
16 *	This product includes software developed by TooLs GmbH.
17 * 4. The name of TooLs GmbH may not be used to endorse or promote products
18 *    derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 *
31 *	$NetBSD: clock.c,v 1.9 2000/01/19 02:52:19 msaitoh Exp $
32 */
33/*
34 * Copyright (C) 2001 Benno Rice.
35 * All rights reserved.
36 *
37 * Redistribution and use in source and binary forms, with or without
38 * modification, are permitted provided that the following conditions
39 * are met:
40 * 1. Redistributions of source code must retain the above copyright
41 *    notice, this list of conditions and the following disclaimer.
42 * 2. Redistributions in binary form must reproduce the above copyright
43 *    notice, this list of conditions and the following disclaimer in the
44 *    documentation and/or other materials provided with the distribution.
45 *
46 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
47 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
49 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
50 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
51 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
52 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
53 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
54 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
55 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57
58#include <sys/cdefs.h>
59__FBSDID("$FreeBSD$");
60
61#include <sys/param.h>
62#include <sys/systm.h>
63#include <sys/kernel.h>
64#include <sys/bus.h>
65#include <sys/interrupt.h>
66#include <sys/pcpu.h>
67#include <sys/sysctl.h>
68#include <sys/timeet.h>
69#include <sys/timetc.h>
70
71#include <dev/ofw/openfirm.h>
72
73#include <machine/clock.h>
74#include <machine/cpu.h>
75#include <machine/intr_machdep.h>
76#include <machine/md_var.h>
77#include <machine/smp.h>
78
79/*
80 * Initially we assume a processor with a bus frequency of 12.5 MHz.
81 */
82static int		initialized = 0;
83static u_long		ns_per_tick = 80;
84static u_long		ticks_per_sec = 12500000;
85static u_long		*decr_counts[MAXCPU];
86
87static int		decr_et_start(struct eventtimer *et,
88    sbintime_t first, sbintime_t period);
89static int		decr_et_stop(struct eventtimer *et);
90static timecounter_get_t	decr_get_timecount;
91
92struct decr_state {
93	int	mode;	/* 0 - off, 1 - periodic, 2 - one-shot. */
94	int32_t	div;	/* Periodic divisor. */
95};
96static DPCPU_DEFINE(struct decr_state, decr_state);
97
98static struct eventtimer	decr_et;
99static struct timecounter	decr_tc = {
100	decr_get_timecount,	/* get_timecount */
101	0,			/* no poll_pps */
102	~0u,			/* counter_mask */
103	0,			/* frequency */
104	"timebase"		/* name */
105};
106
107/*
108 * Decrementer interrupt handler.
109 */
110void
111decr_intr(struct trapframe *frame)
112{
113	struct decr_state *s = DPCPU_PTR(decr_state);
114	int		nticks = 0;
115	int32_t		val;
116
117	if (!initialized)
118		return;
119
120	(*decr_counts[curcpu])++;
121
122#ifdef BOOKE
123	/*
124	 * Interrupt handler must reset DIS to avoid getting another
125	 * interrupt once EE is enabled.
126	 */
127	mtspr(SPR_TSR, TSR_DIS);
128#endif
129
130	if (s->mode == 1) {
131		/*
132		 * Based on the actual time delay since the last decrementer
133		 * reload, we arrange for earlier interrupt next time.
134		 */
135		__asm ("mfdec %0" : "=r"(val));
136		while (val < 0) {
137			val += s->div;
138			nticks++;
139		}
140		mtdec(val);
141	} else if (s->mode == 2) {
142		nticks = 1;
143		decr_et_stop(NULL);
144	}
145
146	while (nticks-- > 0) {
147		if (decr_et.et_active)
148			decr_et.et_event_cb(&decr_et, decr_et.et_arg);
149	}
150}
151
152void
153cpu_initclocks(void)
154{
155
156	decr_tc_init();
157	cpu_initclocks_bsp();
158}
159
160/*
161 * BSP early initialization.
162 */
163void
164decr_init(void)
165{
166	struct cpuref cpu;
167	char buf[32];
168
169	/*
170	 * Check the BSP's timebase frequency. Sometimes we can't find the BSP,
171	 * so fall back to the first CPU in this case.
172	 */
173	if (platform_smp_get_bsp(&cpu) != 0)
174		platform_smp_first_cpu(&cpu);
175	ticks_per_sec = platform_timebase_freq(&cpu);
176	ns_per_tick = 1000000000 / ticks_per_sec;
177
178	set_cputicker(mftb, ticks_per_sec, 0);
179	snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
180	intrcnt_add(buf, &decr_counts[curcpu]);
181	decr_et_stop(NULL);
182	initialized = 1;
183}
184
185#ifdef SMP
186/*
187 * AP early initialization.
188 */
189void
190decr_ap_init(void)
191{
192	char buf[32];
193
194	snprintf(buf, sizeof(buf), "cpu%d:decrementer", curcpu);
195	intrcnt_add(buf, &decr_counts[curcpu]);
196	decr_et_stop(NULL);
197}
198#endif
199
200/*
201 * Final initialization.
202 */
203void
204decr_tc_init(void)
205{
206
207	decr_tc.tc_frequency = ticks_per_sec;
208	tc_init(&decr_tc);
209	decr_et.et_name = "decrementer";
210	decr_et.et_flags = ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT |
211	    ET_FLAGS_PERCPU;
212	decr_et.et_quality = 1000;
213	decr_et.et_frequency = ticks_per_sec;
214	decr_et.et_min_period = (0x00000002LLU << 32) / ticks_per_sec;
215	decr_et.et_max_period = (0x7fffffffLLU << 32) / ticks_per_sec;
216	decr_et.et_start = decr_et_start;
217	decr_et.et_stop = decr_et_stop;
218	decr_et.et_priv = NULL;
219	et_register(&decr_et);
220}
221
222/*
223 * Event timer start method.
224 */
225static int
226decr_et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
227{
228	struct decr_state *s = DPCPU_PTR(decr_state);
229	uint32_t fdiv;
230#ifdef BOOKE
231	uint32_t tcr;
232#endif
233
234	if (period != 0) {
235		s->mode = 1;
236		s->div = (decr_et.et_frequency * period) >> 32;
237	} else {
238		s->mode = 2;
239		s->div = 0;
240	}
241	if (first != 0)
242		fdiv = (decr_et.et_frequency * first) >> 32;
243	else
244		fdiv = s->div;
245
246#ifdef BOOKE
247	tcr = mfspr(SPR_TCR);
248	tcr |= TCR_DIE;
249	if (s->mode == 1) {
250		mtspr(SPR_DECAR, s->div);
251		tcr |= TCR_ARE;
252	} else
253		tcr &= ~TCR_ARE;
254	mtdec(fdiv);
255	mtspr(SPR_TCR, tcr);
256#else
257	mtdec(fdiv);
258#endif
259
260	return (0);
261}
262
263/*
264 * Event timer stop method.
265 */
266static int
267decr_et_stop(struct eventtimer *et)
268{
269	struct decr_state *s = DPCPU_PTR(decr_state);
270#ifdef BOOKE
271	uint32_t tcr;
272#endif
273
274	s->mode = 0;
275	s->div = 0x7fffffff;
276#ifdef BOOKE
277	tcr = mfspr(SPR_TCR);
278	tcr &= ~(TCR_DIE | TCR_ARE);
279	mtspr(SPR_TCR, tcr);
280#else
281	mtdec(s->div);
282#endif
283	return (0);
284}
285
286/*
287 * Timecounter get method.
288 */
289static unsigned
290decr_get_timecount(struct timecounter *tc)
291{
292	return (mftb());
293}
294
295/*
296 * Wait for about n microseconds (at least!).
297 */
298void
299DELAY(int n)
300{
301	u_quad_t	tb, ttb;
302
303	tb = mftb();
304	ttb = tb + howmany(n * 1000, ns_per_tick);
305	while (tb < ttb)
306		tb = mftb();
307}
308
309