/* * Copyright 2014 Advanced Micro Devices, 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. * */ #include <drm/amdgpu_drm.h> #include "amdgpu.h" #include "atom.h" #include "atombios_encoders.h" #include "amdgpu_pll.h" #include <asm/div64.h> #include <linux/gcd.h> /** * amdgpu_pll_reduce_ratio - fractional number reduction * * @nom: nominator * @den: denominator * @nom_min: minimum value for nominator * @den_min: minimum value for denominator * * Find the greatest common divisor and apply it on both nominator and * denominator, but make nominator and denominator are at least as large * as their minimum values. */ static void amdgpu_pll_reduce_ratio(unsigned *nom, unsigned *den, unsigned nom_min, unsigned den_min) { … } /** * amdgpu_pll_get_fb_ref_div - feedback and ref divider calculation * * @adev: amdgpu_device pointer * @nom: nominator * @den: denominator * @post_div: post divider * @fb_div_max: feedback divider maximum * @ref_div_max: reference divider maximum * @fb_div: resulting feedback divider * @ref_div: resulting reference divider * * Calculate feedback and reference divider for a given post divider. Makes * sure we stay within the limits. */ static void amdgpu_pll_get_fb_ref_div(struct amdgpu_device *adev, unsigned int nom, unsigned int den, unsigned int post_div, unsigned int fb_div_max, unsigned int ref_div_max, unsigned int *fb_div, unsigned int *ref_div) { … } /** * amdgpu_pll_compute - compute PLL paramaters * * @adev: amdgpu_device pointer * @pll: information about the PLL * @freq: requested frequency * @dot_clock_p: resulting pixel clock * @fb_div_p: resulting feedback divider * @frac_fb_div_p: fractional part of the feedback divider * @ref_div_p: resulting reference divider * @post_div_p: resulting reference divider * * Try to calculate the PLL parameters to generate the given frequency: * dot_clock = (ref_freq * feedback_div) / (ref_div * post_div) */ void amdgpu_pll_compute(struct amdgpu_device *adev, struct amdgpu_pll *pll, u32 freq, u32 *dot_clock_p, u32 *fb_div_p, u32 *frac_fb_div_p, u32 *ref_div_p, u32 *post_div_p) { … } /** * amdgpu_pll_get_use_mask - look up a mask of which pplls are in use * * @crtc: drm crtc * * Returns the mask of which PPLLs (Pixel PLLs) are in use. */ u32 amdgpu_pll_get_use_mask(struct drm_crtc *crtc) { … } /** * amdgpu_pll_get_shared_dp_ppll - return the PPLL used by another crtc for DP * * @crtc: drm crtc * * Returns the PPLL (Pixel PLL) used by another crtc/encoder which is * also in DP mode. For DP, a single PPLL can be used for all DP * crtcs/encoders. */ int amdgpu_pll_get_shared_dp_ppll(struct drm_crtc *crtc) { … } /** * amdgpu_pll_get_shared_nondp_ppll - return the PPLL used by another non-DP crtc * * @crtc: drm crtc * * Returns the PPLL (Pixel PLL) used by another non-DP crtc/encoder which can * be shared (i.e., same clock). */ int amdgpu_pll_get_shared_nondp_ppll(struct drm_crtc *crtc) { … }
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