1 /*
2  * Copyright 2012 Red Hat Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: Ben Skeggs
23  */
24 #include "nv04.h"
25 
26 #include <core/device.h>
27 
28 static u64
29 nv04_timer_read(struct nvkm_timer *ptimer)
30 {
31 	struct nv04_timer_priv *priv = (void *)ptimer;
32 	u32 hi, lo;
33 
34 	do {
35 		hi = nv_rd32(priv, NV04_PTIMER_TIME_1);
36 		lo = nv_rd32(priv, NV04_PTIMER_TIME_0);
37 	} while (hi != nv_rd32(priv, NV04_PTIMER_TIME_1));
38 
39 	return ((u64)hi << 32 | lo);
40 }
41 
42 static void
43 nv04_timer_alarm_trigger(struct nvkm_timer *ptimer)
44 {
45 	struct nv04_timer_priv *priv = (void *)ptimer;
46 	struct nvkm_alarm *alarm, *atemp;
47 	unsigned long flags;
48 	LIST_HEAD(exec);
49 
50 	/* move any due alarms off the pending list */
51 	spin_lock_irqsave(&priv->lock, flags);
52 	list_for_each_entry_safe(alarm, atemp, &priv->alarms, head) {
53 		if (alarm->timestamp <= ptimer->read(ptimer))
54 			list_move_tail(&alarm->head, &exec);
55 	}
56 
57 	/* reschedule interrupt for next alarm time */
58 	if (!list_empty(&priv->alarms)) {
59 		alarm = list_first_entry(&priv->alarms, typeof(*alarm), head);
60 		nv_wr32(priv, NV04_PTIMER_ALARM_0, alarm->timestamp);
61 		nv_wr32(priv, NV04_PTIMER_INTR_EN_0, 0x00000001);
62 	} else {
63 		nv_wr32(priv, NV04_PTIMER_INTR_EN_0, 0x00000000);
64 	}
65 	spin_unlock_irqrestore(&priv->lock, flags);
66 
67 	/* execute any pending alarm handlers */
68 	list_for_each_entry_safe(alarm, atemp, &exec, head) {
69 		list_del_init(&alarm->head);
70 		alarm->func(alarm);
71 	}
72 }
73 
74 static void
75 nv04_timer_alarm(struct nvkm_timer *ptimer, u64 time, struct nvkm_alarm *alarm)
76 {
77 	struct nv04_timer_priv *priv = (void *)ptimer;
78 	struct nvkm_alarm *list;
79 	unsigned long flags;
80 
81 	alarm->timestamp = ptimer->read(ptimer) + time;
82 
83 	/* append new alarm to list, in soonest-alarm-first order */
84 	spin_lock_irqsave(&priv->lock, flags);
85 	if (!time) {
86 		if (!list_empty(&alarm->head))
87 			list_del(&alarm->head);
88 	} else {
89 		list_for_each_entry(list, &priv->alarms, head) {
90 			if (list->timestamp > alarm->timestamp)
91 				break;
92 		}
93 		list_add_tail(&alarm->head, &list->head);
94 	}
95 	spin_unlock_irqrestore(&priv->lock, flags);
96 
97 	/* process pending alarms */
98 	nv04_timer_alarm_trigger(ptimer);
99 }
100 
101 static void
102 nv04_timer_alarm_cancel(struct nvkm_timer *ptimer, struct nvkm_alarm *alarm)
103 {
104 	struct nv04_timer_priv *priv = (void *)ptimer;
105 	unsigned long flags;
106 	spin_lock_irqsave(&priv->lock, flags);
107 	list_del_init(&alarm->head);
108 	spin_unlock_irqrestore(&priv->lock, flags);
109 }
110 
111 static void
112 nv04_timer_intr(struct nvkm_subdev *subdev)
113 {
114 	struct nv04_timer_priv *priv = (void *)subdev;
115 	u32 stat = nv_rd32(priv, NV04_PTIMER_INTR_0);
116 
117 	if (stat & 0x00000001) {
118 		nv04_timer_alarm_trigger(&priv->base);
119 		nv_wr32(priv, NV04_PTIMER_INTR_0, 0x00000001);
120 		stat &= ~0x00000001;
121 	}
122 
123 	if (stat) {
124 		nv_error(priv, "unknown stat 0x%08x\n", stat);
125 		nv_wr32(priv, NV04_PTIMER_INTR_0, stat);
126 	}
127 }
128 
129 int
130 nv04_timer_fini(struct nvkm_object *object, bool suspend)
131 {
132 	struct nv04_timer_priv *priv = (void *)object;
133 	if (suspend)
134 		priv->suspend_time = nv04_timer_read(&priv->base);
135 	nv_wr32(priv, NV04_PTIMER_INTR_EN_0, 0x00000000);
136 	return nvkm_timer_fini(&priv->base, suspend);
137 }
138 
139 static int
140 nv04_timer_init(struct nvkm_object *object)
141 {
142 	struct nvkm_device *device = nv_device(object);
143 	struct nv04_timer_priv *priv = (void *)object;
144 	u32 m = 1, f, n, d, lo, hi;
145 	int ret;
146 
147 	ret = nvkm_timer_init(&priv->base);
148 	if (ret)
149 		return ret;
150 
151 	/* aim for 31.25MHz, which gives us nanosecond timestamps */
152 	d = 1000000 / 32;
153 
154 	/* determine base clock for timer source */
155 #if 0 /*XXX*/
156 	if (device->chipset < 0x40) {
157 		n = nvkm_hw_get_clock(device, PLL_CORE);
158 	} else
159 #endif
160 	if (device->chipset <= 0x40) {
161 		/*XXX: figure this out */
162 		f = -1;
163 		n = 0;
164 	} else {
165 		f = device->crystal;
166 		n = f;
167 		while (n < (d * 2)) {
168 			n += (n / m);
169 			m++;
170 		}
171 
172 		nv_wr32(priv, 0x009220, m - 1);
173 	}
174 
175 	if (!n) {
176 		nv_warn(priv, "unknown input clock freq\n");
177 		if (!nv_rd32(priv, NV04_PTIMER_NUMERATOR) ||
178 		    !nv_rd32(priv, NV04_PTIMER_DENOMINATOR)) {
179 			nv_wr32(priv, NV04_PTIMER_NUMERATOR, 1);
180 			nv_wr32(priv, NV04_PTIMER_DENOMINATOR, 1);
181 		}
182 		return 0;
183 	}
184 
185 	/* reduce ratio to acceptable values */
186 	while (((n % 5) == 0) && ((d % 5) == 0)) {
187 		n /= 5;
188 		d /= 5;
189 	}
190 
191 	while (((n % 2) == 0) && ((d % 2) == 0)) {
192 		n /= 2;
193 		d /= 2;
194 	}
195 
196 	while (n > 0xffff || d > 0xffff) {
197 		n >>= 1;
198 		d >>= 1;
199 	}
200 
201 	/* restore the time before suspend */
202 	lo = priv->suspend_time;
203 	hi = (priv->suspend_time >> 32);
204 
205 	nv_debug(priv, "input frequency : %dHz\n", f);
206 	nv_debug(priv, "input multiplier: %d\n", m);
207 	nv_debug(priv, "numerator       : 0x%08x\n", n);
208 	nv_debug(priv, "denominator     : 0x%08x\n", d);
209 	nv_debug(priv, "timer frequency : %dHz\n", (f * m) * d / n);
210 	nv_debug(priv, "time low        : 0x%08x\n", lo);
211 	nv_debug(priv, "time high       : 0x%08x\n", hi);
212 
213 	nv_wr32(priv, NV04_PTIMER_NUMERATOR, n);
214 	nv_wr32(priv, NV04_PTIMER_DENOMINATOR, d);
215 	nv_wr32(priv, NV04_PTIMER_INTR_0, 0xffffffff);
216 	nv_wr32(priv, NV04_PTIMER_INTR_EN_0, 0x00000000);
217 	nv_wr32(priv, NV04_PTIMER_TIME_1, hi);
218 	nv_wr32(priv, NV04_PTIMER_TIME_0, lo);
219 	return 0;
220 }
221 
222 void
223 nv04_timer_dtor(struct nvkm_object *object)
224 {
225 	struct nv04_timer_priv *priv = (void *)object;
226 	return nvkm_timer_destroy(&priv->base);
227 }
228 
229 int
230 nv04_timer_ctor(struct nvkm_object *parent, struct nvkm_object *engine,
231 		struct nvkm_oclass *oclass, void *data, u32 size,
232 		struct nvkm_object **pobject)
233 {
234 	struct nv04_timer_priv *priv;
235 	int ret;
236 
237 	ret = nvkm_timer_create(parent, engine, oclass, &priv);
238 	*pobject = nv_object(priv);
239 	if (ret)
240 		return ret;
241 
242 	priv->base.base.intr = nv04_timer_intr;
243 	priv->base.read = nv04_timer_read;
244 	priv->base.alarm = nv04_timer_alarm;
245 	priv->base.alarm_cancel = nv04_timer_alarm_cancel;
246 	priv->suspend_time = 0;
247 
248 	INIT_LIST_HEAD(&priv->alarms);
249 	spin_lock_init(&priv->lock);
250 	return 0;
251 }
252 
253 struct nvkm_oclass
254 nv04_timer_oclass = {
255 	.handle = NV_SUBDEV(TIMER, 0x04),
256 	.ofuncs = &(struct nvkm_ofuncs) {
257 		.ctor = nv04_timer_ctor,
258 		.dtor = nv04_timer_dtor,
259 		.init = nv04_timer_init,
260 		.fini = nv04_timer_fini,
261 	}
262 };
263