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1 | /* |
2 | * Copyright 2014 Advanced Micro Devices, 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 | */ | |
23 | #include <drm/drmP.h> | |
24 | #include <drm/amdgpu_drm.h> | |
25 | #include "amdgpu.h" | |
26 | #include "atom.h" | |
27 | #include "atombios_encoders.h" | |
28 | #include <asm/div64.h> | |
29 | #include <linux/gcd.h> | |
30 | ||
31 | /** | |
32 | * amdgpu_pll_reduce_ratio - fractional number reduction | |
33 | * | |
34 | * @nom: nominator | |
35 | * @den: denominator | |
36 | * @nom_min: minimum value for nominator | |
37 | * @den_min: minimum value for denominator | |
38 | * | |
39 | * Find the greatest common divisor and apply it on both nominator and | |
40 | * denominator, but make nominator and denominator are at least as large | |
41 | * as their minimum values. | |
42 | */ | |
43 | static void amdgpu_pll_reduce_ratio(unsigned *nom, unsigned *den, | |
44 | unsigned nom_min, unsigned den_min) | |
45 | { | |
46 | unsigned tmp; | |
47 | ||
48 | /* reduce the numbers to a simpler ratio */ | |
49 | tmp = gcd(*nom, *den); | |
50 | *nom /= tmp; | |
51 | *den /= tmp; | |
52 | ||
53 | /* make sure nominator is large enough */ | |
54 | if (*nom < nom_min) { | |
55 | tmp = DIV_ROUND_UP(nom_min, *nom); | |
56 | *nom *= tmp; | |
57 | *den *= tmp; | |
58 | } | |
59 | ||
60 | /* make sure the denominator is large enough */ | |
61 | if (*den < den_min) { | |
62 | tmp = DIV_ROUND_UP(den_min, *den); | |
63 | *nom *= tmp; | |
64 | *den *= tmp; | |
65 | } | |
66 | } | |
67 | ||
68 | /** | |
69 | * amdgpu_pll_get_fb_ref_div - feedback and ref divider calculation | |
70 | * | |
71 | * @nom: nominator | |
72 | * @den: denominator | |
73 | * @post_div: post divider | |
74 | * @fb_div_max: feedback divider maximum | |
75 | * @ref_div_max: reference divider maximum | |
76 | * @fb_div: resulting feedback divider | |
77 | * @ref_div: resulting reference divider | |
78 | * | |
79 | * Calculate feedback and reference divider for a given post divider. Makes | |
80 | * sure we stay within the limits. | |
81 | */ | |
82 | static void amdgpu_pll_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div, | |
83 | unsigned fb_div_max, unsigned ref_div_max, | |
84 | unsigned *fb_div, unsigned *ref_div) | |
85 | { | |
86 | /* limit reference * post divider to a maximum */ | |
87 | ref_div_max = min(128 / post_div, ref_div_max); | |
88 | ||
89 | /* get matching reference and feedback divider */ | |
90 | *ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max); | |
91 | *fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den); | |
92 | ||
93 | /* limit fb divider to its maximum */ | |
94 | if (*fb_div > fb_div_max) { | |
95 | *ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div); | |
96 | *fb_div = fb_div_max; | |
97 | } | |
98 | } | |
99 | ||
100 | /** | |
101 | * amdgpu_pll_compute - compute PLL paramaters | |
102 | * | |
103 | * @pll: information about the PLL | |
104 | * @dot_clock_p: resulting pixel clock | |
105 | * fb_div_p: resulting feedback divider | |
106 | * frac_fb_div_p: fractional part of the feedback divider | |
107 | * ref_div_p: resulting reference divider | |
108 | * post_div_p: resulting reference divider | |
109 | * | |
110 | * Try to calculate the PLL parameters to generate the given frequency: | |
111 | * dot_clock = (ref_freq * feedback_div) / (ref_div * post_div) | |
112 | */ | |
113 | void amdgpu_pll_compute(struct amdgpu_pll *pll, | |
114 | u32 freq, | |
115 | u32 *dot_clock_p, | |
116 | u32 *fb_div_p, | |
117 | u32 *frac_fb_div_p, | |
118 | u32 *ref_div_p, | |
119 | u32 *post_div_p) | |
120 | { | |
121 | unsigned target_clock = pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV ? | |
122 | freq : freq / 10; | |
123 | ||
124 | unsigned fb_div_min, fb_div_max, fb_div; | |
125 | unsigned post_div_min, post_div_max, post_div; | |
126 | unsigned ref_div_min, ref_div_max, ref_div; | |
127 | unsigned post_div_best, diff_best; | |
128 | unsigned nom, den; | |
129 | ||
130 | /* determine allowed feedback divider range */ | |
131 | fb_div_min = pll->min_feedback_div; | |
132 | fb_div_max = pll->max_feedback_div; | |
133 | ||
134 | if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | |
135 | fb_div_min *= 10; | |
136 | fb_div_max *= 10; | |
137 | } | |
138 | ||
139 | /* determine allowed ref divider range */ | |
140 | if (pll->flags & AMDGPU_PLL_USE_REF_DIV) | |
141 | ref_div_min = pll->reference_div; | |
142 | else | |
143 | ref_div_min = pll->min_ref_div; | |
144 | ||
145 | if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && | |
146 | pll->flags & AMDGPU_PLL_USE_REF_DIV) | |
147 | ref_div_max = pll->reference_div; | |
148 | else | |
149 | ref_div_max = pll->max_ref_div; | |
150 | ||
151 | /* determine allowed post divider range */ | |
152 | if (pll->flags & AMDGPU_PLL_USE_POST_DIV) { | |
153 | post_div_min = pll->post_div; | |
154 | post_div_max = pll->post_div; | |
155 | } else { | |
156 | unsigned vco_min, vco_max; | |
157 | ||
158 | if (pll->flags & AMDGPU_PLL_IS_LCD) { | |
159 | vco_min = pll->lcd_pll_out_min; | |
160 | vco_max = pll->lcd_pll_out_max; | |
161 | } else { | |
162 | vco_min = pll->pll_out_min; | |
163 | vco_max = pll->pll_out_max; | |
164 | } | |
165 | ||
166 | if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | |
167 | vco_min *= 10; | |
168 | vco_max *= 10; | |
169 | } | |
170 | ||
171 | post_div_min = vco_min / target_clock; | |
172 | if ((target_clock * post_div_min) < vco_min) | |
173 | ++post_div_min; | |
174 | if (post_div_min < pll->min_post_div) | |
175 | post_div_min = pll->min_post_div; | |
176 | ||
177 | post_div_max = vco_max / target_clock; | |
178 | if ((target_clock * post_div_max) > vco_max) | |
179 | --post_div_max; | |
180 | if (post_div_max > pll->max_post_div) | |
181 | post_div_max = pll->max_post_div; | |
182 | } | |
183 | ||
184 | /* represent the searched ratio as fractional number */ | |
185 | nom = target_clock; | |
186 | den = pll->reference_freq; | |
187 | ||
188 | /* reduce the numbers to a simpler ratio */ | |
189 | amdgpu_pll_reduce_ratio(&nom, &den, fb_div_min, post_div_min); | |
190 | ||
191 | /* now search for a post divider */ | |
192 | if (pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP) | |
193 | post_div_best = post_div_min; | |
194 | else | |
195 | post_div_best = post_div_max; | |
196 | diff_best = ~0; | |
197 | ||
198 | for (post_div = post_div_min; post_div <= post_div_max; ++post_div) { | |
199 | unsigned diff; | |
200 | amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max, | |
201 | ref_div_max, &fb_div, &ref_div); | |
202 | diff = abs(target_clock - (pll->reference_freq * fb_div) / | |
203 | (ref_div * post_div)); | |
204 | ||
205 | if (diff < diff_best || (diff == diff_best && | |
206 | !(pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP))) { | |
207 | ||
208 | post_div_best = post_div; | |
209 | diff_best = diff; | |
210 | } | |
211 | } | |
212 | post_div = post_div_best; | |
213 | ||
214 | /* get the feedback and reference divider for the optimal value */ | |
215 | amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max, ref_div_max, | |
216 | &fb_div, &ref_div); | |
217 | ||
218 | /* reduce the numbers to a simpler ratio once more */ | |
219 | /* this also makes sure that the reference divider is large enough */ | |
220 | amdgpu_pll_reduce_ratio(&fb_div, &ref_div, fb_div_min, ref_div_min); | |
221 | ||
222 | /* avoid high jitter with small fractional dividers */ | |
223 | if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && (fb_div % 10)) { | |
224 | fb_div_min = max(fb_div_min, (9 - (fb_div % 10)) * 20 + 60); | |
225 | if (fb_div < fb_div_min) { | |
226 | unsigned tmp = DIV_ROUND_UP(fb_div_min, fb_div); | |
227 | fb_div *= tmp; | |
228 | ref_div *= tmp; | |
229 | } | |
230 | } | |
231 | ||
232 | /* and finally save the result */ | |
233 | if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | |
234 | *fb_div_p = fb_div / 10; | |
235 | *frac_fb_div_p = fb_div % 10; | |
236 | } else { | |
237 | *fb_div_p = fb_div; | |
238 | *frac_fb_div_p = 0; | |
239 | } | |
240 | ||
241 | *dot_clock_p = ((pll->reference_freq * *fb_div_p * 10) + | |
242 | (pll->reference_freq * *frac_fb_div_p)) / | |
243 | (ref_div * post_div * 10); | |
244 | *ref_div_p = ref_div; | |
245 | *post_div_p = post_div; | |
246 | ||
247 | DRM_DEBUG_KMS("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n", | |
248 | freq, *dot_clock_p * 10, *fb_div_p, *frac_fb_div_p, | |
249 | ref_div, post_div); | |
250 | } | |
251 | ||
252 | /** | |
253 | * amdgpu_pll_get_use_mask - look up a mask of which pplls are in use | |
254 | * | |
255 | * @crtc: drm crtc | |
256 | * | |
257 | * Returns the mask of which PPLLs (Pixel PLLs) are in use. | |
258 | */ | |
259 | u32 amdgpu_pll_get_use_mask(struct drm_crtc *crtc) | |
260 | { | |
261 | struct drm_device *dev = crtc->dev; | |
262 | struct drm_crtc *test_crtc; | |
263 | struct amdgpu_crtc *test_amdgpu_crtc; | |
264 | u32 pll_in_use = 0; | |
265 | ||
266 | list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | |
267 | if (crtc == test_crtc) | |
268 | continue; | |
269 | ||
270 | test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | |
271 | if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | |
272 | pll_in_use |= (1 << test_amdgpu_crtc->pll_id); | |
273 | } | |
274 | return pll_in_use; | |
275 | } | |
276 | ||
277 | /** | |
278 | * amdgpu_pll_get_shared_dp_ppll - return the PPLL used by another crtc for DP | |
279 | * | |
280 | * @crtc: drm crtc | |
281 | * | |
282 | * Returns the PPLL (Pixel PLL) used by another crtc/encoder which is | |
283 | * also in DP mode. For DP, a single PPLL can be used for all DP | |
284 | * crtcs/encoders. | |
285 | */ | |
286 | int amdgpu_pll_get_shared_dp_ppll(struct drm_crtc *crtc) | |
287 | { | |
288 | struct drm_device *dev = crtc->dev; | |
289 | struct drm_crtc *test_crtc; | |
290 | struct amdgpu_crtc *test_amdgpu_crtc; | |
291 | ||
292 | list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | |
293 | if (crtc == test_crtc) | |
294 | continue; | |
295 | test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | |
296 | if (test_amdgpu_crtc->encoder && | |
297 | ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) { | |
298 | /* for DP use the same PLL for all */ | |
299 | if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | |
300 | return test_amdgpu_crtc->pll_id; | |
301 | } | |
302 | } | |
303 | return ATOM_PPLL_INVALID; | |
304 | } | |
305 | ||
306 | /** | |
307 | * amdgpu_pll_get_shared_nondp_ppll - return the PPLL used by another non-DP crtc | |
308 | * | |
309 | * @crtc: drm crtc | |
310 | * @encoder: drm encoder | |
311 | * | |
312 | * Returns the PPLL (Pixel PLL) used by another non-DP crtc/encoder which can | |
313 | * be shared (i.e., same clock). | |
314 | */ | |
315 | int amdgpu_pll_get_shared_nondp_ppll(struct drm_crtc *crtc) | |
316 | { | |
317 | struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc); | |
318 | struct drm_device *dev = crtc->dev; | |
319 | struct drm_crtc *test_crtc; | |
320 | struct amdgpu_crtc *test_amdgpu_crtc; | |
321 | u32 adjusted_clock, test_adjusted_clock; | |
322 | ||
323 | adjusted_clock = amdgpu_crtc->adjusted_clock; | |
324 | ||
325 | if (adjusted_clock == 0) | |
326 | return ATOM_PPLL_INVALID; | |
327 | ||
328 | list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | |
329 | if (crtc == test_crtc) | |
330 | continue; | |
331 | test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | |
332 | if (test_amdgpu_crtc->encoder && | |
333 | !ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) { | |
334 | /* check if we are already driving this connector with another crtc */ | |
335 | if (test_amdgpu_crtc->connector == amdgpu_crtc->connector) { | |
336 | /* if we are, return that pll */ | |
337 | if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | |
338 | return test_amdgpu_crtc->pll_id; | |
339 | } | |
340 | /* for non-DP check the clock */ | |
341 | test_adjusted_clock = test_amdgpu_crtc->adjusted_clock; | |
342 | if ((crtc->mode.clock == test_crtc->mode.clock) && | |
343 | (adjusted_clock == test_adjusted_clock) && | |
344 | (amdgpu_crtc->ss_enabled == test_amdgpu_crtc->ss_enabled) && | |
345 | (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)) | |
346 | return test_amdgpu_crtc->pll_id; | |
347 | } | |
348 | } | |
349 | return ATOM_PPLL_INVALID; | |
350 | } |