1 /*
2 * Copyright 2010 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
25 #include "drmP.h"
26 #include "nouveau_drv.h"
27 #include "nouveau_hw.h"
28
29 int
nv50_calc_pll(struct drm_device * dev,struct pll_lims * pll,int clk,int * N1,int * M1,int * N2,int * M2,int * P)30 nv50_calc_pll(struct drm_device *dev, struct pll_lims *pll, int clk,
31 int *N1, int *M1, int *N2, int *M2, int *P)
32 {
33 struct nouveau_pll_vals pll_vals;
34 int ret;
35
36 ret = nouveau_calc_pll_mnp(dev, pll, clk, &pll_vals);
37 if (ret <= 0)
38 return ret;
39
40 *N1 = pll_vals.N1;
41 *M1 = pll_vals.M1;
42 *N2 = pll_vals.N2;
43 *M2 = pll_vals.M2;
44 *P = pll_vals.log2P;
45 return ret;
46 }
47
48 int
nva3_calc_pll(struct drm_device * dev,struct pll_lims * pll,int clk,int * pN,int * pfN,int * pM,int * P)49 nva3_calc_pll(struct drm_device *dev, struct pll_lims *pll, int clk,
50 int *pN, int *pfN, int *pM, int *P)
51 {
52 u32 best_err = ~0, err;
53 int M, lM, hM, N, fN;
54
55 *P = pll->vco1.maxfreq / clk;
56 if (*P > pll->max_p)
57 *P = pll->max_p;
58 if (*P < pll->min_p)
59 *P = pll->min_p;
60
61 lM = (pll->refclk + pll->vco1.max_inputfreq) / pll->vco1.max_inputfreq;
62 lM = max(lM, (int)pll->vco1.min_m);
63 hM = (pll->refclk + pll->vco1.min_inputfreq) / pll->vco1.min_inputfreq;
64 hM = min(hM, (int)pll->vco1.max_m);
65
66 for (M = lM; M <= hM; M++) {
67 u32 tmp = clk * *P * M;
68 N = tmp / pll->refclk;
69 fN = tmp % pll->refclk;
70 if (!pfN && fN >= pll->refclk / 2)
71 N++;
72
73 if (N < pll->vco1.min_n)
74 continue;
75 if (N > pll->vco1.max_n)
76 break;
77
78 err = abs(clk - (pll->refclk * N / M / *P));
79 if (err < best_err) {
80 best_err = err;
81 *pN = N;
82 *pM = M;
83 }
84
85 if (pfN) {
86 *pfN = (((fN << 13) / pll->refclk) - 4096) & 0xffff;
87 return clk;
88 }
89 }
90
91 if (unlikely(best_err == ~0)) {
92 NV_ERROR(dev, "unable to find matching pll values\n");
93 return -EINVAL;
94 }
95
96 return pll->refclk * *pN / *pM / *P;
97 }
98