projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| e9ebb68b BS |
1 | /* |
| 2 | * Copyright 2010 Red Hat Inc. | |
| 3 | * | |
| 4 | * Permission is hereby granted, free of charge, to any person obtaining a | |
| 5 | * copy of this software and associated documentation files (the "Software"), | |
| 6 | * to deal in the Software without restriction, including without limitation | |
| 7 | * the rights to use, copy, modify, merge, publish, distribute, sublicense, | |
| 8 | * and/or sell copies of the Software, and to permit persons to whom the | |
| 9 | * Software is furnished to do so, subject to the following conditions: | |
| 10 | * | |
| 11 | * The above copyright notice and this permission notice shall be included in | |
| 12 | * all copies or substantial portions of the Software. | |
| 13 | * | |
| 14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
| 15 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
| 16 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL | |
| 17 | * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | |
| 18 | * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | |
| 19 | * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | |
| 20 | * OTHER DEALINGS IN THE SOFTWARE. | |
| 21 | * | |
| 22 | * Authors: Ben Skeggs | |
| 23 | */ | |
| 7632b30e | 24 | #include "pll.h" |
| e9ebb68b | 25 | |
| 70790f4f BS |
26 | #include <subdev/bios.h> |
| 27 | #include <subdev/bios/pll.h> | |
| e9ebb68b | 28 | |
| e9ebb68b | 29 | int |
| 7632b30e BS |
30 | gt215_pll_calc(struct nvkm_subdev *subdev, struct nvbios_pll *info, |
| 31 | u32 freq, int *pN, int *pfN, int *pM, int *P) | |
| e9ebb68b | 32 | { |
| 52eba8dd BS |
33 | u32 best_err = ~0, err; |
| 34 | int M, lM, hM, N, fN; | |
| e9ebb68b | 35 | |
| 70790f4f BS |
36 | *P = info->vco1.max_freq / freq; |
| 37 | if (*P > info->max_p) | |
| 38 | *P = info->max_p; | |
| 39 | if (*P < info->min_p) | |
| 40 | *P = info->min_p; | |
| e9ebb68b | 41 | |
| 70790f4f BS |
42 | lM = (info->refclk + info->vco1.max_inputfreq) / info->vco1.max_inputfreq; |
| 43 | lM = max(lM, (int)info->vco1.min_m); | |
| 44 | hM = (info->refclk + info->vco1.min_inputfreq) / info->vco1.min_inputfreq; | |
| 45 | hM = min(hM, (int)info->vco1.max_m); | |
| aae95ca7 | 46 | lM = min(lM, hM); |
| e9ebb68b | 47 | |
| 52eba8dd | 48 | for (M = lM; M <= hM; M++) { |
| 70790f4f BS |
49 | u32 tmp = freq * *P * M; |
| 50 | N = tmp / info->refclk; | |
| 51 | fN = tmp % info->refclk; | |
| da746d4e BS |
52 | |
| 53 | if (!pfN) { | |
| 54 | if (fN >= info->refclk / 2) | |
| 55 | N++; | |
| 56 | } else { | |
| 57 | if (fN < info->refclk / 2) | |
| 58 | N--; | |
| 59 | fN = tmp - (N * info->refclk); | |
| 60 | } | |
| e9ebb68b | 61 | |
| 70790f4f | 62 | if (N < info->vco1.min_n) |
| 52eba8dd | 63 | continue; |
| 70790f4f | 64 | if (N > info->vco1.max_n) |
| 52eba8dd | 65 | break; |
| e9ebb68b | 66 | |
| 70790f4f | 67 | err = abs(freq - (info->refclk * N / M / *P)); |
| 52eba8dd BS |
68 | if (err < best_err) { |
| 69 | best_err = err; | |
| 70 | *pN = N; | |
| 71 | *pM = M; | |
| 72 | } | |
| e9ebb68b | 73 | |
| 52eba8dd | 74 | if (pfN) { |
| da746d4e BS |
75 | *pfN = ((fN << 13) + info->refclk / 2) / info->refclk; |
| 76 | *pfN = (*pfN - 4096) & 0xffff; | |
| 70790f4f | 77 | return freq; |
| 52eba8dd BS |
78 | } |
| 79 | } | |
| 80 | ||
| 81 | if (unlikely(best_err == ~0)) { | |
| b907649e | 82 | nvkm_error(subdev, "unable to find matching pll values\n"); |
| 52eba8dd BS |
83 | return -EINVAL; |
| 84 | } | |
| 85 | ||
| 70790f4f | 86 | return info->refclk * *pN / *pM / *P; |
| e9ebb68b | 87 | } |