1 /* $NetBSD: nouveau_subdev_clock_pllnv04.c,v 1.1.1.1 2014/08/06 12:36:29 riastradh Exp $ */
2
3 /*
4 * Copyright 1993-2003 NVIDIA, Corporation
5 * Copyright 2007-2009 Stuart Bennett
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #include <sys/cdefs.h>
27 __KERNEL_RCSID(0, "$NetBSD: nouveau_subdev_clock_pllnv04.c,v 1.1.1.1 2014/08/06 12:36:29 riastradh Exp $");
28
29 #include <subdev/bios.h>
30 #include <subdev/bios/pll.h>
31
32 #include "pll.h"
33
34 static int
getMNP_single(struct nouveau_subdev * subdev,struct nvbios_pll * info,int clk,int * pN,int * pM,int * pP)35 getMNP_single(struct nouveau_subdev *subdev, struct nvbios_pll *info, int clk,
36 int *pN, int *pM, int *pP)
37 {
38 /* Find M, N and P for a single stage PLL
39 *
40 * Note that some bioses (NV3x) have lookup tables of precomputed MNP
41 * values, but we're too lazy to use those atm
42 *
43 * "clk" parameter in kHz
44 * returns calculated clock
45 */
46 struct nouveau_bios *bios = nouveau_bios(subdev);
47 int minvco = info->vco1.min_freq, maxvco = info->vco1.max_freq;
48 int minM = info->vco1.min_m, maxM = info->vco1.max_m;
49 int minN = info->vco1.min_n, maxN = info->vco1.max_n;
50 int minU = info->vco1.min_inputfreq;
51 int maxU = info->vco1.max_inputfreq;
52 int minP = info->min_p;
53 int maxP = info->max_p_usable;
54 int crystal = info->refclk;
55 int M, N, thisP, P;
56 int clkP, calcclk;
57 int delta, bestdelta = INT_MAX;
58 int bestclk = 0;
59
60 /* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */
61 /* possibly correlated with introduction of 27MHz crystal */
62 if (bios->version.major < 0x60) {
63 int cv = bios->version.chip;
64 if (cv < 0x17 || cv == 0x1a || cv == 0x20) {
65 if (clk > 250000)
66 maxM = 6;
67 if (clk > 340000)
68 maxM = 2;
69 } else if (cv < 0x40) {
70 if (clk > 150000)
71 maxM = 6;
72 if (clk > 200000)
73 maxM = 4;
74 if (clk > 340000)
75 maxM = 2;
76 }
77 }
78
79 P = 1 << maxP;
80 if ((clk * P) < minvco) {
81 minvco = clk * maxP;
82 maxvco = minvco * 2;
83 }
84
85 if (clk + clk/200 > maxvco) /* +0.5% */
86 maxvco = clk + clk/200;
87
88 /* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */
89 for (thisP = minP; thisP <= maxP; thisP++) {
90 P = 1 << thisP;
91 clkP = clk * P;
92
93 if (clkP < minvco)
94 continue;
95 if (clkP > maxvco)
96 return bestclk;
97
98 for (M = minM; M <= maxM; M++) {
99 if (crystal/M < minU)
100 return bestclk;
101 if (crystal/M > maxU)
102 continue;
103
104 /* add crystal/2 to round better */
105 N = (clkP * M + crystal/2) / crystal;
106
107 if (N < minN)
108 continue;
109 if (N > maxN)
110 break;
111
112 /* more rounding additions */
113 calcclk = ((N * crystal + P/2) / P + M/2) / M;
114 delta = abs(calcclk - clk);
115 /* we do an exhaustive search rather than terminating
116 * on an optimality condition...
117 */
118 if (delta < bestdelta) {
119 bestdelta = delta;
120 bestclk = calcclk;
121 *pN = N;
122 *pM = M;
123 *pP = thisP;
124 if (delta == 0) /* except this one */
125 return bestclk;
126 }
127 }
128 }
129
130 return bestclk;
131 }
132
133 static int
getMNP_double(struct nouveau_subdev * subdev,struct nvbios_pll * info,int clk,int * pN1,int * pM1,int * pN2,int * pM2,int * pP)134 getMNP_double(struct nouveau_subdev *subdev, struct nvbios_pll *info, int clk,
135 int *pN1, int *pM1, int *pN2, int *pM2, int *pP)
136 {
137 /* Find M, N and P for a two stage PLL
138 *
139 * Note that some bioses (NV30+) have lookup tables of precomputed MNP
140 * values, but we're too lazy to use those atm
141 *
142 * "clk" parameter in kHz
143 * returns calculated clock
144 */
145 int chip_version = nouveau_bios(subdev)->version.chip;
146 int minvco1 = info->vco1.min_freq, maxvco1 = info->vco1.max_freq;
147 int minvco2 = info->vco2.min_freq, maxvco2 = info->vco2.max_freq;
148 int minU1 = info->vco1.min_inputfreq, minU2 = info->vco2.min_inputfreq;
149 int maxU1 = info->vco1.max_inputfreq, maxU2 = info->vco2.max_inputfreq;
150 int minM1 = info->vco1.min_m, maxM1 = info->vco1.max_m;
151 int minN1 = info->vco1.min_n, maxN1 = info->vco1.max_n;
152 int minM2 = info->vco2.min_m, maxM2 = info->vco2.max_m;
153 int minN2 = info->vco2.min_n, maxN2 = info->vco2.max_n;
154 int maxlog2P = info->max_p_usable;
155 int crystal = info->refclk;
156 bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2);
157 int M1, N1, M2, N2, log2P;
158 int clkP, calcclk1, calcclk2, calcclkout;
159 int delta, bestdelta = INT_MAX;
160 int bestclk = 0;
161
162 int vco2 = (maxvco2 - maxvco2/200) / 2;
163 for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++)
164 ;
165 clkP = clk << log2P;
166
167 if (maxvco2 < clk + clk/200) /* +0.5% */
168 maxvco2 = clk + clk/200;
169
170 for (M1 = minM1; M1 <= maxM1; M1++) {
171 if (crystal/M1 < minU1)
172 return bestclk;
173 if (crystal/M1 > maxU1)
174 continue;
175
176 for (N1 = minN1; N1 <= maxN1; N1++) {
177 calcclk1 = crystal * N1 / M1;
178 if (calcclk1 < minvco1)
179 continue;
180 if (calcclk1 > maxvco1)
181 break;
182
183 for (M2 = minM2; M2 <= maxM2; M2++) {
184 if (calcclk1/M2 < minU2)
185 break;
186 if (calcclk1/M2 > maxU2)
187 continue;
188
189 /* add calcclk1/2 to round better */
190 N2 = (clkP * M2 + calcclk1/2) / calcclk1;
191 if (N2 < minN2)
192 continue;
193 if (N2 > maxN2)
194 break;
195
196 if (!fixedgain2) {
197 if (chip_version < 0x60)
198 if (N2/M2 < 4 || N2/M2 > 10)
199 continue;
200
201 calcclk2 = calcclk1 * N2 / M2;
202 if (calcclk2 < minvco2)
203 break;
204 if (calcclk2 > maxvco2)
205 continue;
206 } else
207 calcclk2 = calcclk1;
208
209 calcclkout = calcclk2 >> log2P;
210 delta = abs(calcclkout - clk);
211 /* we do an exhaustive search rather than terminating
212 * on an optimality condition...
213 */
214 if (delta < bestdelta) {
215 bestdelta = delta;
216 bestclk = calcclkout;
217 *pN1 = N1;
218 *pM1 = M1;
219 *pN2 = N2;
220 *pM2 = M2;
221 *pP = log2P;
222 if (delta == 0) /* except this one */
223 return bestclk;
224 }
225 }
226 }
227 }
228
229 return bestclk;
230 }
231
232 int
nv04_pll_calc(struct nouveau_subdev * subdev,struct nvbios_pll * info,u32 freq,int * N1,int * M1,int * N2,int * M2,int * P)233 nv04_pll_calc(struct nouveau_subdev *subdev, struct nvbios_pll *info, u32 freq,
234 int *N1, int *M1, int *N2, int *M2, int *P)
235 {
236 int ret;
237
238 if (!info->vco2.max_freq || !N2) {
239 ret = getMNP_single(subdev, info, freq, N1, M1, P);
240 if (N2) {
241 *N2 = 1;
242 *M2 = 1;
243 }
244 } else {
245 ret = getMNP_double(subdev, info, freq, N1, M1, N2, M2, P);
246 }
247
248 if (!ret)
249 nv_error(subdev, "unable to compute acceptable pll values\n");
250 return ret;
251 }
252