2 * Copyright 1993-2003 NVIDIA, Corporation
3 * Copyright 2007-2009 Stuart Bennett
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:
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
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
24 #include <subdev/bios.h>
25 #include <subdev/bios/pll.h>
30 getMNP_single(struct nouveau_subdev *subdev, struct nvbios_pll *info, int clk,
31 int *pN, int *pM, int *pP)
33 /* Find M, N and P for a single stage PLL
35 * Note that some bioses (NV3x) have lookup tables of precomputed MNP
36 * values, but we're too lazy to use those atm
38 * "clk" parameter in kHz
39 * returns calculated clock
41 int cv = nouveau_bios(subdev)->version.chip;
42 int minvco = info->vco1.min_freq, maxvco = info->vco1.max_freq;
43 int minM = info->vco1.min_m, maxM = info->vco1.max_m;
44 int minN = info->vco1.min_n, maxN = info->vco1.max_n;
45 int minU = info->vco1.min_inputfreq;
46 int maxU = info->vco1.max_inputfreq;
47 int minP = info->min_p;
48 int maxP = info->max_p_usable;
49 int crystal = info->refclk;
52 int delta, bestdelta = INT_MAX;
55 /* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */
56 /* possibly correlated with introduction of 27MHz crystal */
57 if (cv < 0x17 || cv == 0x1a || cv == 0x20) {
62 } else if (cv < 0x40) {
72 if ((clk * P) < minvco) {
77 if (clk + clk/200 > maxvco) /* +0.5% */
78 maxvco = clk + clk/200;
80 /* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */
81 for (thisP = minP; thisP <= maxP; thisP++) {
90 for (M = minM; M <= maxM; M++) {
96 /* add crystal/2 to round better */
97 N = (clkP * M + crystal/2) / crystal;
104 /* more rounding additions */
105 calcclk = ((N * crystal + P/2) / P + M/2) / M;
106 delta = abs(calcclk - clk);
107 /* we do an exhaustive search rather than terminating
108 * on an optimality condition...
110 if (delta < bestdelta) {
116 if (delta == 0) /* except this one */
126 getMNP_double(struct nouveau_subdev *subdev, struct nvbios_pll *info, int clk,
127 int *pN1, int *pM1, int *pN2, int *pM2, int *pP)
129 /* Find M, N and P for a two stage PLL
131 * Note that some bioses (NV30+) have lookup tables of precomputed MNP
132 * values, but we're too lazy to use those atm
134 * "clk" parameter in kHz
135 * returns calculated clock
137 int chip_version = nouveau_bios(subdev)->version.chip;
138 int minvco1 = info->vco1.min_freq, maxvco1 = info->vco1.max_freq;
139 int minvco2 = info->vco2.min_freq, maxvco2 = info->vco2.max_freq;
140 int minU1 = info->vco1.min_inputfreq, minU2 = info->vco2.min_inputfreq;
141 int maxU1 = info->vco1.max_inputfreq, maxU2 = info->vco2.max_inputfreq;
142 int minM1 = info->vco1.min_m, maxM1 = info->vco1.max_m;
143 int minN1 = info->vco1.min_n, maxN1 = info->vco1.max_n;
144 int minM2 = info->vco2.min_m, maxM2 = info->vco2.max_m;
145 int minN2 = info->vco2.min_n, maxN2 = info->vco2.max_n;
146 int maxlog2P = info->max_p_usable;
147 int crystal = info->refclk;
148 bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2);
149 int M1, N1, M2, N2, log2P;
150 int clkP, calcclk1, calcclk2, calcclkout;
151 int delta, bestdelta = INT_MAX;
154 int vco2 = (maxvco2 - maxvco2/200) / 2;
155 for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++)
159 if (maxvco2 < clk + clk/200) /* +0.5% */
160 maxvco2 = clk + clk/200;
162 for (M1 = minM1; M1 <= maxM1; M1++) {
163 if (crystal/M1 < minU1)
165 if (crystal/M1 > maxU1)
168 for (N1 = minN1; N1 <= maxN1; N1++) {
169 calcclk1 = crystal * N1 / M1;
170 if (calcclk1 < minvco1)
172 if (calcclk1 > maxvco1)
175 for (M2 = minM2; M2 <= maxM2; M2++) {
176 if (calcclk1/M2 < minU2)
178 if (calcclk1/M2 > maxU2)
181 /* add calcclk1/2 to round better */
182 N2 = (clkP * M2 + calcclk1/2) / calcclk1;
189 if (chip_version < 0x60)
190 if (N2/M2 < 4 || N2/M2 > 10)
193 calcclk2 = calcclk1 * N2 / M2;
194 if (calcclk2 < minvco2)
196 if (calcclk2 > maxvco2)
201 calcclkout = calcclk2 >> log2P;
202 delta = abs(calcclkout - clk);
203 /* we do an exhaustive search rather than terminating
204 * on an optimality condition...
206 if (delta < bestdelta) {
208 bestclk = calcclkout;
214 if (delta == 0) /* except this one */
225 nv04_pll_calc(struct nouveau_subdev *subdev, struct nvbios_pll *info, u32 freq,
226 int *N1, int *M1, int *N2, int *M2, int *P)
230 if (!info->vco2.max_freq) {
231 ret = getMNP_single(subdev, info, freq, N1, M1, P);
235 ret = getMNP_double(subdev, info, freq, N1, M1, N2, M2, P);
239 nv_error(subdev, "unable to compute acceptable pll values\n");