mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-10-31 08:26:29 +00:00
88 lines
2.5 KiB
C
88 lines
2.5 KiB
C
/*
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* Copyright 2010 Red Hat Inc.
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
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* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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* OTHER DEALINGS IN THE SOFTWARE.
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*
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* Authors: Ben Skeggs
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*/
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#include "drmP.h"
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#include "drm_fixed.h"
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#include "nouveau_drv.h"
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#include "nouveau_hw.h"
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int
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nv50_calc_pll(struct drm_device *dev, struct pll_lims *pll, int clk,
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int *N1, int *M1, int *N2, int *M2, int *P)
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{
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struct nouveau_pll_vals pll_vals;
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int ret;
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ret = nouveau_calc_pll_mnp(dev, pll, clk, &pll_vals);
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if (ret <= 0)
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return ret;
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*N1 = pll_vals.N1;
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*M1 = pll_vals.M1;
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*N2 = pll_vals.N2;
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*M2 = pll_vals.M2;
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*P = pll_vals.log2P;
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return ret;
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}
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int
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nv50_calc_pll2(struct drm_device *dev, struct pll_lims *pll, int clk,
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int *N, int *fN, int *M, int *P)
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{
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fixed20_12 fb_div, a, b;
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*P = pll->vco1.maxfreq / clk;
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if (*P > pll->max_p)
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*P = pll->max_p;
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if (*P < pll->min_p)
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*P = pll->min_p;
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/* *M = ceil(refclk / pll->vco.max_inputfreq); */
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a.full = dfixed_const(pll->refclk);
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b.full = dfixed_const(pll->vco1.max_inputfreq);
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a.full = dfixed_div(a, b);
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a.full = dfixed_ceil(a);
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*M = dfixed_trunc(a);
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/* fb_div = (vco * *M) / refclk; */
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fb_div.full = dfixed_const(clk * *P);
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fb_div.full = dfixed_mul(fb_div, a);
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a.full = dfixed_const(pll->refclk);
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fb_div.full = dfixed_div(fb_div, a);
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/* *N = floor(fb_div); */
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a.full = dfixed_floor(fb_div);
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*N = dfixed_trunc(fb_div);
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/* *fN = (fmod(fb_div, 1.0) * 8192) - 4096; */
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b.full = dfixed_const(8192);
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a.full = dfixed_mul(a, b);
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fb_div.full = dfixed_mul(fb_div, b);
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fb_div.full = fb_div.full - a.full;
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*fN = dfixed_trunc(fb_div) - 4096;
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*fN &= 0xffff;
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return clk;
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}
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