projects / deliverable / linux.git / blame
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|---|---|---|
| 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 | */ | |
| 24 | ||
| 70790f4f BS |
25 | #include <subdev/clock.h> |
| 26 | #include <subdev/bios.h> | |
| 27 | #include <subdev/bios/pll.h> | |
| e9ebb68b | 28 | |
| 70790f4f | 29 | #include "pll.h" |
| e9ebb68b BS |
30 | |
| 31 | int | |
| 7ada785f | 32 | nva3_pll_calc(struct nouveau_subdev *subdev, struct nvbios_pll *info, |
| 70790f4f | 33 | u32 freq, int *pN, int *pfN, int *pM, int *P) |
| e9ebb68b | 34 | { |
| 52eba8dd BS |
35 | u32 best_err = ~0, err; |
| 36 | int M, lM, hM, N, fN; | |
| e9ebb68b | 37 | |
| 70790f4f BS |
38 | *P = info->vco1.max_freq / freq; |
| 39 | if (*P > info->max_p) | |
| 40 | *P = info->max_p; | |
| 41 | if (*P < info->min_p) | |
| 42 | *P = info->min_p; | |
| e9ebb68b | 43 | |
| 70790f4f BS |
44 | lM = (info->refclk + info->vco1.max_inputfreq) / info->vco1.max_inputfreq; |
| 45 | lM = max(lM, (int)info->vco1.min_m); | |
| 46 | hM = (info->refclk + info->vco1.min_inputfreq) / info->vco1.min_inputfreq; | |
| 47 | hM = min(hM, (int)info->vco1.max_m); | |
| aae95ca7 | 48 | lM = min(lM, hM); |
| e9ebb68b | 49 | |
| 52eba8dd | 50 | for (M = lM; M <= hM; M++) { |
| 70790f4f BS |
51 | u32 tmp = freq * *P * M; |
| 52 | N = tmp / info->refclk; | |
| 53 | fN = tmp % info->refclk; | |
| da746d4e BS |
54 | |
| 55 | if (!pfN) { | |
| 56 | if (fN >= info->refclk / 2) | |
| 57 | N++; | |
| 58 | } else { | |
| 59 | if (fN < info->refclk / 2) | |
| 60 | N--; | |
| 61 | fN = tmp - (N * info->refclk); | |
| 62 | } | |
| e9ebb68b | 63 | |
| 70790f4f | 64 | if (N < info->vco1.min_n) |
| 52eba8dd | 65 | continue; |
| 70790f4f | 66 | if (N > info->vco1.max_n) |
| 52eba8dd | 67 | break; |
| e9ebb68b | 68 | |
| 70790f4f | 69 | err = abs(freq - (info->refclk * N / M / *P)); |
| 52eba8dd BS |
70 | if (err < best_err) { |
| 71 | best_err = err; | |
| 72 | *pN = N; | |
| 73 | *pM = M; | |
| 74 | } | |
| e9ebb68b | 75 | |
| 52eba8dd | 76 | if (pfN) { |
| da746d4e BS |
77 | *pfN = ((fN << 13) + info->refclk / 2) / info->refclk; |
| 78 | *pfN = (*pfN - 4096) & 0xffff; | |
| 70790f4f | 79 | return freq; |
| 52eba8dd BS |
80 | } |
| 81 | } | |
| 82 | ||
| 83 | if (unlikely(best_err == ~0)) { | |
| 7ada785f | 84 | nv_error(subdev, "unable to find matching pll values\n"); |
| 52eba8dd BS |
85 | return -EINVAL; |
| 86 | } | |
| 87 | ||
| 70790f4f | 88 | return info->refclk * *pN / *pM / *P; |
| e9ebb68b | 89 | } |