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/clock.h>
25 #include <subdev/bios.h>
26 #include <subdev/bios/pll.h>
31 getMNP_single(struct nouveau_clock *clock, struct nvbios_pll *info, int clk,
32 int *pN, int *pM, int *pP)
34 /* Find M, N and P for a single stage PLL
36 * Note that some bioses (NV3x) have lookup tables of precomputed MNP
37 * values, but we're too lazy to use those atm
39 * "clk" parameter in kHz
40 * returns calculated clock
42 int cv = nouveau_bios(clock)->version.chip;
43 int minvco = info->vco1.min_freq, maxvco = info->vco1.max_freq;
44 int minM = info->vco1.min_m, maxM = info->vco1.max_m;
45 int minN = info->vco1.min_n, maxN = info->vco1.max_n;
46 int minU = info->vco1.min_inputfreq;
47 int maxU = info->vco1.max_inputfreq;
48 int minP = info->min_p;
49 int maxP = info->max_p_usable;
50 int crystal = info->refclk;
53 int delta, bestdelta = INT_MAX;
56 /* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */
57 /* possibly correlated with introduction of 27MHz crystal */
58 if (cv < 0x17 || cv == 0x1a || cv == 0x20) {
63 } else if (cv < 0x40) {
73 if ((clk * P) < minvco) {
78 if (clk + clk/200 > maxvco) /* +0.5% */
79 maxvco = clk + clk/200;
81 /* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */
82 for (thisP = minP; thisP <= maxP; thisP++) {
91 for (M = minM; M <= maxM; M++) {
97 /* add crystal/2 to round better */
98 N = (clkP * M + crystal/2) / crystal;
105 /* more rounding additions */
106 calcclk = ((N * crystal + P/2) / P + M/2) / M;
107 delta = abs(calcclk - clk);
108 /* we do an exhaustive search rather than terminating
109 * on an optimality condition...
111 if (delta < bestdelta) {
117 if (delta == 0) /* except this one */
127 getMNP_double(struct nouveau_clock *clock, struct nvbios_pll *info, int clk,
128 int *pN1, int *pM1, int *pN2, int *pM2, int *pP)
130 /* Find M, N and P for a two stage PLL
132 * Note that some bioses (NV30+) have lookup tables of precomputed MNP
133 * values, but we're too lazy to use those atm
135 * "clk" parameter in kHz
136 * returns calculated clock
138 int chip_version = nouveau_bios(clock)->version.chip;
139 int minvco1 = info->vco1.min_freq, maxvco1 = info->vco1.max_freq;
140 int minvco2 = info->vco2.min_freq, maxvco2 = info->vco2.max_freq;
141 int minU1 = info->vco1.min_inputfreq, minU2 = info->vco2.min_inputfreq;
142 int maxU1 = info->vco1.max_inputfreq, maxU2 = info->vco2.max_inputfreq;
143 int minM1 = info->vco1.min_m, maxM1 = info->vco1.max_m;
144 int minN1 = info->vco1.min_n, maxN1 = info->vco1.max_n;
145 int minM2 = info->vco2.min_m, maxM2 = info->vco2.max_m;
146 int minN2 = info->vco2.min_n, maxN2 = info->vco2.max_n;
147 int maxlog2P = info->max_p_usable;
148 int crystal = info->refclk;
149 bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2);
150 int M1, N1, M2, N2, log2P;
151 int clkP, calcclk1, calcclk2, calcclkout;
152 int delta, bestdelta = INT_MAX;
155 int vco2 = (maxvco2 - maxvco2/200) / 2;
156 for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++)
160 if (maxvco2 < clk + clk/200) /* +0.5% */
161 maxvco2 = clk + clk/200;
163 for (M1 = minM1; M1 <= maxM1; M1++) {
164 if (crystal/M1 < minU1)
166 if (crystal/M1 > maxU1)
169 for (N1 = minN1; N1 <= maxN1; N1++) {
170 calcclk1 = crystal * N1 / M1;
171 if (calcclk1 < minvco1)
173 if (calcclk1 > maxvco1)
176 for (M2 = minM2; M2 <= maxM2; M2++) {
177 if (calcclk1/M2 < minU2)
179 if (calcclk1/M2 > maxU2)
182 /* add calcclk1/2 to round better */
183 N2 = (clkP * M2 + calcclk1/2) / calcclk1;
190 if (chip_version < 0x60)
191 if (N2/M2 < 4 || N2/M2 > 10)
194 calcclk2 = calcclk1 * N2 / M2;
195 if (calcclk2 < minvco2)
197 if (calcclk2 > maxvco2)
202 calcclkout = calcclk2 >> log2P;
203 delta = abs(calcclkout - clk);
204 /* we do an exhaustive search rather than terminating
205 * on an optimality condition...
207 if (delta < bestdelta) {
209 bestclk = calcclkout;
215 if (delta == 0) /* except this one */
226 nv04_pll_calc(struct nouveau_clock *clk, struct nvbios_pll *info, u32 freq,
227 int *N1, int *M1, int *N2, int *M2, int *P)
231 if (!info->vco2.max_freq) {
232 ret = getMNP_single(clk, info, freq, N1, M1, P);
236 ret = getMNP_double(clk, info, freq, N1, M1, N2, M2, P);
240 nv_error(clk, "unable to compute acceptable pll values\n");