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70790f4f BS |
1 | /* |
2 | * Copyright 1993-2003 NVIDIA, Corporation | |
3 | * Copyright 2007-2009 Stuart Bennett | |
4 | * | |
5 | * Permission is hereby granted, free of charge, to any person obtaining a | |
6 | * copy of this software and associated documentation files (the "Software"), | |
7 | * to deal in the Software without restriction, including without limitation | |
8 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
9 | * and/or sell copies of the Software, and to permit persons to whom the | |
10 | * Software is furnished to do so, subject to the following conditions: | |
11 | * | |
12 | * The above copyright notice and this permission notice shall be included in | |
13 | * all copies or substantial portions of the Software. | |
14 | * | |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
18 | * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, | |
19 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF | |
20 | * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE | |
21 | * SOFTWARE. | |
22 | */ | |
7632b30e | 23 | #include "pll.h" |
70790f4f | 24 | |
70790f4f BS |
25 | #include <subdev/bios.h> |
26 | #include <subdev/bios/pll.h> | |
27 | ||
70790f4f | 28 | static int |
7632b30e | 29 | getMNP_single(struct nvkm_subdev *subdev, struct nvbios_pll *info, int clk, |
70790f4f BS |
30 | int *pN, int *pM, int *pP) |
31 | { | |
32 | /* Find M, N and P for a single stage PLL | |
33 | * | |
34 | * Note that some bioses (NV3x) have lookup tables of precomputed MNP | |
35 | * values, but we're too lazy to use those atm | |
36 | * | |
37 | * "clk" parameter in kHz | |
38 | * returns calculated clock | |
39 | */ | |
46484438 | 40 | struct nvkm_bios *bios = subdev->device->bios; |
70790f4f BS |
41 | int minvco = info->vco1.min_freq, maxvco = info->vco1.max_freq; |
42 | int minM = info->vco1.min_m, maxM = info->vco1.max_m; | |
43 | int minN = info->vco1.min_n, maxN = info->vco1.max_n; | |
44 | int minU = info->vco1.min_inputfreq; | |
45 | int maxU = info->vco1.max_inputfreq; | |
46 | int minP = info->min_p; | |
47 | int maxP = info->max_p_usable; | |
48 | int crystal = info->refclk; | |
49 | int M, N, thisP, P; | |
50 | int clkP, calcclk; | |
51 | int delta, bestdelta = INT_MAX; | |
52 | int bestclk = 0; | |
53 | ||
54 | /* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */ | |
55 | /* possibly correlated with introduction of 27MHz crystal */ | |
d29b9924 BS |
56 | if (bios->version.major < 0x60) { |
57 | int cv = bios->version.chip; | |
58 | if (cv < 0x17 || cv == 0x1a || cv == 0x20) { | |
59 | if (clk > 250000) | |
60 | maxM = 6; | |
61 | if (clk > 340000) | |
62 | maxM = 2; | |
63 | } else if (cv < 0x40) { | |
64 | if (clk > 150000) | |
65 | maxM = 6; | |
66 | if (clk > 200000) | |
67 | maxM = 4; | |
68 | if (clk > 340000) | |
69 | maxM = 2; | |
70 | } | |
70790f4f BS |
71 | } |
72 | ||
73 | P = 1 << maxP; | |
74 | if ((clk * P) < minvco) { | |
75 | minvco = clk * maxP; | |
76 | maxvco = minvco * 2; | |
77 | } | |
78 | ||
79 | if (clk + clk/200 > maxvco) /* +0.5% */ | |
80 | maxvco = clk + clk/200; | |
81 | ||
82 | /* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */ | |
83 | for (thisP = minP; thisP <= maxP; thisP++) { | |
84 | P = 1 << thisP; | |
85 | clkP = clk * P; | |
86 | ||
87 | if (clkP < minvco) | |
88 | continue; | |
89 | if (clkP > maxvco) | |
90 | return bestclk; | |
91 | ||
92 | for (M = minM; M <= maxM; M++) { | |
93 | if (crystal/M < minU) | |
94 | return bestclk; | |
95 | if (crystal/M > maxU) | |
96 | continue; | |
97 | ||
98 | /* add crystal/2 to round better */ | |
99 | N = (clkP * M + crystal/2) / crystal; | |
100 | ||
101 | if (N < minN) | |
102 | continue; | |
103 | if (N > maxN) | |
104 | break; | |
105 | ||
106 | /* more rounding additions */ | |
107 | calcclk = ((N * crystal + P/2) / P + M/2) / M; | |
108 | delta = abs(calcclk - clk); | |
109 | /* we do an exhaustive search rather than terminating | |
110 | * on an optimality condition... | |
111 | */ | |
112 | if (delta < bestdelta) { | |
113 | bestdelta = delta; | |
114 | bestclk = calcclk; | |
115 | *pN = N; | |
116 | *pM = M; | |
117 | *pP = thisP; | |
118 | if (delta == 0) /* except this one */ | |
119 | return bestclk; | |
120 | } | |
121 | } | |
122 | } | |
123 | ||
124 | return bestclk; | |
125 | } | |
126 | ||
127 | static int | |
7632b30e | 128 | getMNP_double(struct nvkm_subdev *subdev, struct nvbios_pll *info, int clk, |
70790f4f BS |
129 | int *pN1, int *pM1, int *pN2, int *pM2, int *pP) |
130 | { | |
131 | /* Find M, N and P for a two stage PLL | |
132 | * | |
133 | * Note that some bioses (NV30+) have lookup tables of precomputed MNP | |
134 | * values, but we're too lazy to use those atm | |
135 | * | |
136 | * "clk" parameter in kHz | |
137 | * returns calculated clock | |
138 | */ | |
46484438 | 139 | int chip_version = subdev->device->bios->version.chip; |
70790f4f BS |
140 | int minvco1 = info->vco1.min_freq, maxvco1 = info->vco1.max_freq; |
141 | int minvco2 = info->vco2.min_freq, maxvco2 = info->vco2.max_freq; | |
142 | int minU1 = info->vco1.min_inputfreq, minU2 = info->vco2.min_inputfreq; | |
143 | int maxU1 = info->vco1.max_inputfreq, maxU2 = info->vco2.max_inputfreq; | |
144 | int minM1 = info->vco1.min_m, maxM1 = info->vco1.max_m; | |
145 | int minN1 = info->vco1.min_n, maxN1 = info->vco1.max_n; | |
146 | int minM2 = info->vco2.min_m, maxM2 = info->vco2.max_m; | |
147 | int minN2 = info->vco2.min_n, maxN2 = info->vco2.max_n; | |
148 | int maxlog2P = info->max_p_usable; | |
149 | int crystal = info->refclk; | |
150 | bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2); | |
151 | int M1, N1, M2, N2, log2P; | |
152 | int clkP, calcclk1, calcclk2, calcclkout; | |
153 | int delta, bestdelta = INT_MAX; | |
154 | int bestclk = 0; | |
155 | ||
156 | int vco2 = (maxvco2 - maxvco2/200) / 2; | |
157 | for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++) | |
158 | ; | |
159 | clkP = clk << log2P; | |
160 | ||
161 | if (maxvco2 < clk + clk/200) /* +0.5% */ | |
162 | maxvco2 = clk + clk/200; | |
163 | ||
164 | for (M1 = minM1; M1 <= maxM1; M1++) { | |
165 | if (crystal/M1 < minU1) | |
166 | return bestclk; | |
167 | if (crystal/M1 > maxU1) | |
168 | continue; | |
169 | ||
170 | for (N1 = minN1; N1 <= maxN1; N1++) { | |
171 | calcclk1 = crystal * N1 / M1; | |
172 | if (calcclk1 < minvco1) | |
173 | continue; | |
174 | if (calcclk1 > maxvco1) | |
175 | break; | |
176 | ||
177 | for (M2 = minM2; M2 <= maxM2; M2++) { | |
178 | if (calcclk1/M2 < minU2) | |
179 | break; | |
180 | if (calcclk1/M2 > maxU2) | |
181 | continue; | |
182 | ||
183 | /* add calcclk1/2 to round better */ | |
184 | N2 = (clkP * M2 + calcclk1/2) / calcclk1; | |
185 | if (N2 < minN2) | |
186 | continue; | |
187 | if (N2 > maxN2) | |
188 | break; | |
189 | ||
190 | if (!fixedgain2) { | |
191 | if (chip_version < 0x60) | |
192 | if (N2/M2 < 4 || N2/M2 > 10) | |
193 | continue; | |
194 | ||
195 | calcclk2 = calcclk1 * N2 / M2; | |
196 | if (calcclk2 < minvco2) | |
197 | break; | |
198 | if (calcclk2 > maxvco2) | |
199 | continue; | |
200 | } else | |
201 | calcclk2 = calcclk1; | |
202 | ||
203 | calcclkout = calcclk2 >> log2P; | |
204 | delta = abs(calcclkout - clk); | |
205 | /* we do an exhaustive search rather than terminating | |
206 | * on an optimality condition... | |
207 | */ | |
208 | if (delta < bestdelta) { | |
209 | bestdelta = delta; | |
210 | bestclk = calcclkout; | |
211 | *pN1 = N1; | |
212 | *pM1 = M1; | |
213 | *pN2 = N2; | |
214 | *pM2 = M2; | |
215 | *pP = log2P; | |
216 | if (delta == 0) /* except this one */ | |
217 | return bestclk; | |
218 | } | |
219 | } | |
220 | } | |
221 | } | |
222 | ||
223 | return bestclk; | |
224 | } | |
225 | ||
226 | int | |
7632b30e | 227 | nv04_pll_calc(struct nvkm_subdev *subdev, struct nvbios_pll *info, u32 freq, |
70790f4f BS |
228 | int *N1, int *M1, int *N2, int *M2, int *P) |
229 | { | |
230 | int ret; | |
231 | ||
7c856522 | 232 | if (!info->vco2.max_freq || !N2) { |
7ada785f | 233 | ret = getMNP_single(subdev, info, freq, N1, M1, P); |
7c856522 BS |
234 | if (N2) { |
235 | *N2 = 1; | |
236 | *M2 = 1; | |
237 | } | |
70790f4f | 238 | } else { |
7ada785f | 239 | ret = getMNP_double(subdev, info, freq, N1, M1, N2, M2, P); |
70790f4f BS |
240 | } |
241 | ||
242 | if (!ret) | |
b907649e | 243 | nvkm_error(subdev, "unable to compute acceptable pll values\n"); |
70790f4f BS |
244 | return ret; |
245 | } |