| /* |
| * Copyright 1993-2003 NVIDIA, Corporation |
| * Copyright 2007-2009 Stuart Bennett |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF |
| * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. |
| */ |
| #include "pll.h" |
| |
| #include <subdev/bios.h> |
| #include <subdev/bios/pll.h> |
| |
| static int |
| getMNP_single(struct nvkm_subdev *subdev, struct nvbios_pll *info, int clk, |
| int *pN, int *pM, int *pP) |
| { |
| /* Find M, N and P for a single stage PLL |
| * |
| * Note that some bioses (NV3x) have lookup tables of precomputed MNP |
| * values, but we're too lazy to use those atm |
| * |
| * "clk" parameter in kHz |
| * returns calculated clock |
| */ |
| struct nvkm_bios *bios = nvkm_bios(subdev); |
| int minvco = info->vco1.min_freq, maxvco = info->vco1.max_freq; |
| int minM = info->vco1.min_m, maxM = info->vco1.max_m; |
| int minN = info->vco1.min_n, maxN = info->vco1.max_n; |
| int minU = info->vco1.min_inputfreq; |
| int maxU = info->vco1.max_inputfreq; |
| int minP = info->min_p; |
| int maxP = info->max_p_usable; |
| int crystal = info->refclk; |
| int M, N, thisP, P; |
| int clkP, calcclk; |
| int delta, bestdelta = INT_MAX; |
| int bestclk = 0; |
| |
| /* this division verified for nv20, nv18, nv28 (Haiku), and nv34 */ |
| /* possibly correlated with introduction of 27MHz crystal */ |
| if (bios->version.major < 0x60) { |
| int cv = bios->version.chip; |
| if (cv < 0x17 || cv == 0x1a || cv == 0x20) { |
| if (clk > 250000) |
| maxM = 6; |
| if (clk > 340000) |
| maxM = 2; |
| } else if (cv < 0x40) { |
| if (clk > 150000) |
| maxM = 6; |
| if (clk > 200000) |
| maxM = 4; |
| if (clk > 340000) |
| maxM = 2; |
| } |
| } |
| |
| P = 1 << maxP; |
| if ((clk * P) < minvco) { |
| minvco = clk * maxP; |
| maxvco = minvco * 2; |
| } |
| |
| if (clk + clk/200 > maxvco) /* +0.5% */ |
| maxvco = clk + clk/200; |
| |
| /* NV34 goes maxlog2P->0, NV20 goes 0->maxlog2P */ |
| for (thisP = minP; thisP <= maxP; thisP++) { |
| P = 1 << thisP; |
| clkP = clk * P; |
| |
| if (clkP < minvco) |
| continue; |
| if (clkP > maxvco) |
| return bestclk; |
| |
| for (M = minM; M <= maxM; M++) { |
| if (crystal/M < minU) |
| return bestclk; |
| if (crystal/M > maxU) |
| continue; |
| |
| /* add crystal/2 to round better */ |
| N = (clkP * M + crystal/2) / crystal; |
| |
| if (N < minN) |
| continue; |
| if (N > maxN) |
| break; |
| |
| /* more rounding additions */ |
| calcclk = ((N * crystal + P/2) / P + M/2) / M; |
| delta = abs(calcclk - clk); |
| /* we do an exhaustive search rather than terminating |
| * on an optimality condition... |
| */ |
| if (delta < bestdelta) { |
| bestdelta = delta; |
| bestclk = calcclk; |
| *pN = N; |
| *pM = M; |
| *pP = thisP; |
| if (delta == 0) /* except this one */ |
| return bestclk; |
| } |
| } |
| } |
| |
| return bestclk; |
| } |
| |
| static int |
| getMNP_double(struct nvkm_subdev *subdev, struct nvbios_pll *info, int clk, |
| int *pN1, int *pM1, int *pN2, int *pM2, int *pP) |
| { |
| /* Find M, N and P for a two stage PLL |
| * |
| * Note that some bioses (NV30+) have lookup tables of precomputed MNP |
| * values, but we're too lazy to use those atm |
| * |
| * "clk" parameter in kHz |
| * returns calculated clock |
| */ |
| int chip_version = nvkm_bios(subdev)->version.chip; |
| int minvco1 = info->vco1.min_freq, maxvco1 = info->vco1.max_freq; |
| int minvco2 = info->vco2.min_freq, maxvco2 = info->vco2.max_freq; |
| int minU1 = info->vco1.min_inputfreq, minU2 = info->vco2.min_inputfreq; |
| int maxU1 = info->vco1.max_inputfreq, maxU2 = info->vco2.max_inputfreq; |
| int minM1 = info->vco1.min_m, maxM1 = info->vco1.max_m; |
| int minN1 = info->vco1.min_n, maxN1 = info->vco1.max_n; |
| int minM2 = info->vco2.min_m, maxM2 = info->vco2.max_m; |
| int minN2 = info->vco2.min_n, maxN2 = info->vco2.max_n; |
| int maxlog2P = info->max_p_usable; |
| int crystal = info->refclk; |
| bool fixedgain2 = (minM2 == maxM2 && minN2 == maxN2); |
| int M1, N1, M2, N2, log2P; |
| int clkP, calcclk1, calcclk2, calcclkout; |
| int delta, bestdelta = INT_MAX; |
| int bestclk = 0; |
| |
| int vco2 = (maxvco2 - maxvco2/200) / 2; |
| for (log2P = 0; clk && log2P < maxlog2P && clk <= (vco2 >> log2P); log2P++) |
| ; |
| clkP = clk << log2P; |
| |
| if (maxvco2 < clk + clk/200) /* +0.5% */ |
| maxvco2 = clk + clk/200; |
| |
| for (M1 = minM1; M1 <= maxM1; M1++) { |
| if (crystal/M1 < minU1) |
| return bestclk; |
| if (crystal/M1 > maxU1) |
| continue; |
| |
| for (N1 = minN1; N1 <= maxN1; N1++) { |
| calcclk1 = crystal * N1 / M1; |
| if (calcclk1 < minvco1) |
| continue; |
| if (calcclk1 > maxvco1) |
| break; |
| |
| for (M2 = minM2; M2 <= maxM2; M2++) { |
| if (calcclk1/M2 < minU2) |
| break; |
| if (calcclk1/M2 > maxU2) |
| continue; |
| |
| /* add calcclk1/2 to round better */ |
| N2 = (clkP * M2 + calcclk1/2) / calcclk1; |
| if (N2 < minN2) |
| continue; |
| if (N2 > maxN2) |
| break; |
| |
| if (!fixedgain2) { |
| if (chip_version < 0x60) |
| if (N2/M2 < 4 || N2/M2 > 10) |
| continue; |
| |
| calcclk2 = calcclk1 * N2 / M2; |
| if (calcclk2 < minvco2) |
| break; |
| if (calcclk2 > maxvco2) |
| continue; |
| } else |
| calcclk2 = calcclk1; |
| |
| calcclkout = calcclk2 >> log2P; |
| delta = abs(calcclkout - clk); |
| /* we do an exhaustive search rather than terminating |
| * on an optimality condition... |
| */ |
| if (delta < bestdelta) { |
| bestdelta = delta; |
| bestclk = calcclkout; |
| *pN1 = N1; |
| *pM1 = M1; |
| *pN2 = N2; |
| *pM2 = M2; |
| *pP = log2P; |
| if (delta == 0) /* except this one */ |
| return bestclk; |
| } |
| } |
| } |
| } |
| |
| return bestclk; |
| } |
| |
| int |
| nv04_pll_calc(struct nvkm_subdev *subdev, struct nvbios_pll *info, u32 freq, |
| int *N1, int *M1, int *N2, int *M2, int *P) |
| { |
| int ret; |
| |
| if (!info->vco2.max_freq || !N2) { |
| ret = getMNP_single(subdev, info, freq, N1, M1, P); |
| if (N2) { |
| *N2 = 1; |
| *M2 = 1; |
| } |
| } else { |
| ret = getMNP_double(subdev, info, freq, N1, M1, N2, M2, P); |
| } |
| |
| if (!ret) |
| nv_error(subdev, "unable to compute acceptable pll values\n"); |
| return ret; |
| } |
