1/* $NetBSD: nouveau_subdev_clock_pllnva3.c,v 1.1.1.1 2014/08/06 12:36:29 riastradh Exp $ */
2
3/*
4 * Copyright 2010 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
27#include <sys/cdefs.h>
28__KERNEL_RCSID(0, "$NetBSD: nouveau_subdev_clock_pllnva3.c,v 1.1.1.1 2014/08/06 12:36:29 riastradh Exp $");
29
30#include <subdev/clock.h>
31#include <subdev/bios.h>
32#include <subdev/bios/pll.h>
33
34#include "pll.h"
35
36int
37nva3_pll_calc(struct nouveau_subdev *subdev, struct nvbios_pll *info,
38 u32 freq, int *pN, int *pfN, int *pM, int *P)
39{
40 u32 best_err = ~0, err;
41 int M, lM, hM, N, fN;
42
43 *P = info->vco1.max_freq / freq;
44 if (*P > info->max_p)
45 *P = info->max_p;
46 if (*P < info->min_p)
47 *P = info->min_p;
48
49 lM = (info->refclk + info->vco1.max_inputfreq) / info->vco1.max_inputfreq;
50 lM = max(lM, (int)info->vco1.min_m);
51 hM = (info->refclk + info->vco1.min_inputfreq) / info->vco1.min_inputfreq;
52 hM = min(hM, (int)info->vco1.max_m);
53 lM = min(lM, hM);
54
55 for (M = lM; M <= hM; M++) {
56 u32 tmp = freq * *P * M;
57 N = tmp / info->refclk;
58 fN = tmp % info->refclk;
59
60 if (!pfN) {
61 if (fN >= info->refclk / 2)
62 N++;
63 } else {
64 if (fN < info->refclk / 2)
65 N--;
66 fN = tmp - (N * info->refclk);
67 }
68
69 if (N < info->vco1.min_n)
70 continue;
71 if (N > info->vco1.max_n)
72 break;
73
74 err = abs(freq - (info->refclk * N / M / *P));
75 if (err < best_err) {
76 best_err = err;
77 *pN = N;
78 *pM = M;
79 }
80
81 if (pfN) {
82 *pfN = ((fN << 13) + info->refclk / 2) / info->refclk;
83 *pfN = (*pfN - 4096) & 0xffff;
84 return freq;
85 }
86 }
87
88 if (unlikely(best_err == ~0)) {
89 nv_error(subdev, "unable to find matching pll values\n");
90 return -EINVAL;
91 }
92
93 return info->refclk * *pN / *pM / *P;
94}
95