1 /* $NetBSD: nouveau_nvkm_subdev_timer_nv41.c,v 1.3 2021/12/18 23:45:42 riastradh Exp $ */
2
3 /*
4 * Copyright 2012 Red Hat Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: Ben Skeggs
25 */
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_timer_nv41.c,v 1.3 2021/12/18 23:45:42 riastradh Exp $");
28
29 #include "priv.h"
30 #include "regsnv04.h"
31
32 static void
nv41_timer_init(struct nvkm_timer * tmr)33 nv41_timer_init(struct nvkm_timer *tmr)
34 {
35 struct nvkm_subdev *subdev = &tmr->subdev;
36 struct nvkm_device *device = subdev->device;
37 u32 f = device->crystal;
38 u32 m = 1, n, d;
39
40 /* aim for 31.25MHz, which gives us nanosecond timestamps */
41 d = 1000000 / 32;
42 n = f;
43
44 while (n < (d * 2)) {
45 n += (n / m);
46 m++;
47 }
48
49 /* reduce ratio to acceptable values */
50 while (((n % 5) == 0) && ((d % 5) == 0)) {
51 n /= 5;
52 d /= 5;
53 }
54
55 while (((n % 2) == 0) && ((d % 2) == 0)) {
56 n /= 2;
57 d /= 2;
58 }
59
60 while (n > 0xffff || d > 0xffff) {
61 n >>= 1;
62 d >>= 1;
63 }
64
65 nvkm_debug(subdev, "input frequency : %dHz\n", f);
66 nvkm_debug(subdev, "input multiplier: %d\n", m);
67 nvkm_debug(subdev, "numerator : %08x\n", n);
68 nvkm_debug(subdev, "denominator : %08x\n", d);
69 nvkm_debug(subdev, "timer frequency : %dHz\n", (f * m) * d / n);
70
71 nvkm_wr32(device, 0x009220, m - 1);
72 nvkm_wr32(device, NV04_PTIMER_NUMERATOR, n);
73 nvkm_wr32(device, NV04_PTIMER_DENOMINATOR, d);
74 }
75
76 static const struct nvkm_timer_func
77 nv41_timer = {
78 .init = nv41_timer_init,
79 .intr = nv04_timer_intr,
80 .read = nv04_timer_read,
81 .time = nv04_timer_time,
82 .alarm_init = nv04_timer_alarm_init,
83 .alarm_fini = nv04_timer_alarm_fini,
84 };
85
86 int
nv41_timer_new(struct nvkm_device * device,int index,struct nvkm_timer ** ptmr)87 nv41_timer_new(struct nvkm_device *device, int index, struct nvkm_timer **ptmr)
88 {
89 return nvkm_timer_new_(&nv41_timer, device, index, ptmr);
90 }
91