diff options
Diffstat (limited to 'drivers/gpu/drm/nouveau/nvkm/subdev/clk/pllgt215.c')
| -rw-r--r-- | drivers/gpu/drm/nouveau/nvkm/subdev/clk/pllgt215.c | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/clk/pllgt215.c b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/pllgt215.c new file mode 100644 index 000000000000..783a3e78d632 --- /dev/null +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/clk/pllgt215.c @@ -0,0 +1,87 @@ +/* + * Copyright 2010 Red Hat Inc. + * + * 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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. + * + * Authors: Ben Skeggs + */ +#include "pll.h" + +#include <subdev/bios.h> +#include <subdev/bios/pll.h> + +int +gt215_pll_calc(struct nvkm_subdev *subdev, struct nvbios_pll *info, + u32 freq, int *pN, int *pfN, int *pM, int *P) +{ + u32 best_err = ~0, err; + int M, lM, hM, N, fN; + + *P = info->vco1.max_freq / freq; + if (*P > info->max_p) + *P = info->max_p; + if (*P < info->min_p) + *P = info->min_p; + + lM = (info->refclk + info->vco1.max_inputfreq) / info->vco1.max_inputfreq; + lM = max(lM, (int)info->vco1.min_m); + hM = (info->refclk + info->vco1.min_inputfreq) / info->vco1.min_inputfreq; + hM = min(hM, (int)info->vco1.max_m); + lM = min(lM, hM); + + for (M = lM; M <= hM; M++) { + u32 tmp = freq * *P * M; + N = tmp / info->refclk; + fN = tmp % info->refclk; + + if (!pfN) { + if (fN >= info->refclk / 2) + N++; + } else { + if (fN < info->refclk / 2) + N--; + fN = tmp - (N * info->refclk); + } + + if (N < info->vco1.min_n) + continue; + if (N > info->vco1.max_n) + break; + + err = abs(freq - (info->refclk * N / M / *P)); + if (err < best_err) { + best_err = err; + *pN = N; + *pM = M; + } + + if (pfN) { + *pfN = ((fN << 13) + info->refclk / 2) / info->refclk; + *pfN = (*pfN - 4096) & 0xffff; + return freq; + } + } + + if (unlikely(best_err == ~0)) { + nv_error(subdev, "unable to find matching pll values\n"); + return -EINVAL; + } + + return info->refclk * *pN / *pM / *P; +} |