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/* * 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){	unsigned tmp; 	/* reduce the numbers to a simpler ratio */	tmp = gcd(*nom, *den);	*nom /= tmp;	*den /= tmp; 	/* make sure nominator is large enough */	if (*nom < nom_min) {		tmp = DIV_ROUND_UP(nom_min, *nom);		*nom *= tmp;		*den *= tmp;	} 	/* make sure the denominator is large enough */	if (*den < den_min) {		tmp = DIV_ROUND_UP(den_min, *den);		*nom *= tmp;		*den *= tmp;	}} /** * 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){ 	/* limit reference * post divider to a maximum */	if (adev->family == AMDGPU_FAMILY_SI)		ref_div_max = min(100 / post_div, ref_div_max);	else		ref_div_max = min(128 / post_div, ref_div_max); 	/* get matching reference and feedback divider */	*ref_div = clamp(DIV_ROUND_CLOSEST(den, post_div), 1u, ref_div_max);	*fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den); 	/* limit fb divider to its maximum */	if (*fb_div > fb_div_max) {		*ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div);		*fb_div = fb_div_max;	}} /** * 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){	unsigned target_clock = pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV ?		freq : freq / 10; 	unsigned fb_div_min, fb_div_max, fb_div;	unsigned post_div_min, post_div_max, post_div;	unsigned ref_div_min, ref_div_max, ref_div;	unsigned post_div_best, diff_best;	unsigned nom, den; 	/* determine allowed feedback divider range */	fb_div_min = pll->min_feedback_div;	fb_div_max = pll->max_feedback_div; 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {		fb_div_min *= 10;		fb_div_max *= 10;	} 	/* determine allowed ref divider range */	if (pll->flags & AMDGPU_PLL_USE_REF_DIV)		ref_div_min = pll->reference_div;	else		ref_div_min = pll->min_ref_div; 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV &&	    pll->flags & AMDGPU_PLL_USE_REF_DIV)		ref_div_max = pll->reference_div;	else		ref_div_max = pll->max_ref_div; 	/* determine allowed post divider range */	if (pll->flags & AMDGPU_PLL_USE_POST_DIV) {		post_div_min = pll->post_div;		post_div_max = pll->post_div;	} else {		unsigned vco_min, vco_max; 		if (pll->flags & AMDGPU_PLL_IS_LCD) {			vco_min = pll->lcd_pll_out_min;			vco_max = pll->lcd_pll_out_max;		} else {			vco_min = pll->pll_out_min;			vco_max = pll->pll_out_max;		} 		if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {			vco_min *= 10;			vco_max *= 10;		} 		post_div_min = vco_min / target_clock;		if ((target_clock * post_div_min) < vco_min)			++post_div_min;		if (post_div_min < pll->min_post_div)			post_div_min = pll->min_post_div; 		post_div_max = vco_max / target_clock;		if ((target_clock * post_div_max) > vco_max)			--post_div_max;		if (post_div_max > pll->max_post_div)			post_div_max = pll->max_post_div;	} 	/* represent the searched ratio as fractional number */	nom = target_clock;	den = pll->reference_freq; 	/* reduce the numbers to a simpler ratio */	amdgpu_pll_reduce_ratio(&nom, &den, fb_div_min, post_div_min); 	/* now search for a post divider */	if (pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP)		post_div_best = post_div_min;	else		post_div_best = post_div_max;	diff_best = ~0; 	for (post_div = post_div_min; post_div <= post_div_max; ++post_div) {		unsigned diff;		amdgpu_pll_get_fb_ref_div(adev, nom, den, post_div, fb_div_max,					  ref_div_max, &fb_div, &ref_div);		diff = abs(target_clock - (pll->reference_freq * fb_div) /			(ref_div * post_div)); 		if (diff < diff_best || (diff == diff_best &&		    !(pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP))) { 			post_div_best = post_div;			diff_best = diff;		}	}	post_div = post_div_best; 	/* get the feedback and reference divider for the optimal value */	amdgpu_pll_get_fb_ref_div(adev, nom, den, post_div, fb_div_max, ref_div_max,				  &fb_div, &ref_div); 	/* reduce the numbers to a simpler ratio once more */	/* this also makes sure that the reference divider is large enough */	amdgpu_pll_reduce_ratio(&fb_div, &ref_div, fb_div_min, ref_div_min); 	/* avoid high jitter with small fractional dividers */	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && (fb_div % 10)) {		fb_div_min = max(fb_div_min, (9 - (fb_div % 10)) * 20 + 60);		if (fb_div < fb_div_min) {			unsigned tmp = DIV_ROUND_UP(fb_div_min, fb_div);			fb_div *= tmp;			ref_div *= tmp;		}	} 	/* and finally save the result */	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {		*fb_div_p = fb_div / 10;		*frac_fb_div_p = fb_div % 10;	} else {		*fb_div_p = fb_div;		*frac_fb_div_p = 0;	} 	*dot_clock_p = ((pll->reference_freq * *fb_div_p * 10) +			(pll->reference_freq * *frac_fb_div_p)) /		       (ref_div * post_div * 10);	*ref_div_p = ref_div;	*post_div_p = post_div; 	DRM_DEBUG_KMS("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n",		      freq, *dot_clock_p * 10, *fb_div_p, *frac_fb_div_p,		      ref_div, post_div);} /** * 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){	struct drm_device *dev = crtc->dev;	struct drm_crtc *test_crtc;	struct amdgpu_crtc *test_amdgpu_crtc;	u32 pll_in_use = 0; 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {		if (crtc == test_crtc)			continue; 		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);		if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)			pll_in_use |= (1 << test_amdgpu_crtc->pll_id);	}	return pll_in_use;} /** * 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){	struct drm_device *dev = crtc->dev;	struct drm_crtc *test_crtc;	struct amdgpu_crtc *test_amdgpu_crtc; 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {		if (crtc == test_crtc)			continue;		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);		if (test_amdgpu_crtc->encoder &&		    ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) {			/* for DP use the same PLL for all */			if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)				return test_amdgpu_crtc->pll_id;		}	}	return ATOM_PPLL_INVALID;} /** * 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){	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);	struct drm_device *dev = crtc->dev;	struct drm_crtc *test_crtc;	struct amdgpu_crtc *test_amdgpu_crtc;	u32 adjusted_clock, test_adjusted_clock; 	adjusted_clock = amdgpu_crtc->adjusted_clock; 	if (adjusted_clock == 0)		return ATOM_PPLL_INVALID; 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {		if (crtc == test_crtc)			continue;		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);		if (test_amdgpu_crtc->encoder &&		    !ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) {			/* check if we are already driving this connector with another crtc */			if (test_amdgpu_crtc->connector == amdgpu_crtc->connector) {				/* if we are, return that pll */				if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)					return test_amdgpu_crtc->pll_id;			}			/* for non-DP check the clock */			test_adjusted_clock = test_amdgpu_crtc->adjusted_clock;			if ((crtc->mode.clock == test_crtc->mode.clock) &&			    (adjusted_clock == test_adjusted_clock) &&			    (amdgpu_crtc->ss_enabled == test_amdgpu_crtc->ss_enabled) &&			    (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID))				return test_amdgpu_crtc->pll_id;		}	}	return ATOM_PPLL_INVALID;}