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1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2021 Intel Corporation
4 */
5
6#include "i915_drv.h"
7#include "i915_reg.h"
8#include "intel_atomic.h"
9#include "intel_de.h"
10#include "intel_display_types.h"
11#include "intel_drrs.h"
12#include "intel_frontbuffer.h"
13#include "intel_panel.h"
14
15/**
16 * DOC: Display Refresh Rate Switching (DRRS)
17 *
18 * Display Refresh Rate Switching (DRRS) is a power conservation feature
19 * which enables swtching between low and high refresh rates,
20 * dynamically, based on the usage scenario. This feature is applicable
21 * for internal panels.
22 *
23 * Indication that the panel supports DRRS is given by the panel EDID, which
24 * would list multiple refresh rates for one resolution.
25 *
26 * DRRS is of 2 types - static and seamless.
27 * Static DRRS involves changing refresh rate (RR) by doing a full modeset
28 * (may appear as a blink on screen) and is used in dock-undock scenario.
29 * Seamless DRRS involves changing RR without any visual effect to the user
30 * and can be used during normal system usage. This is done by programming
31 * certain registers.
32 *
33 * Support for static/seamless DRRS may be indicated in the VBT based on
34 * inputs from the panel spec.
35 *
36 * DRRS saves power by switching to low RR based on usage scenarios.
37 *
38 * The implementation is based on frontbuffer tracking implementation. When
39 * there is a disturbance on the screen triggered by user activity or a periodic
40 * system activity, DRRS is disabled (RR is changed to high RR). When there is
41 * no movement on screen, after a timeout of 1 second, a switch to low RR is
42 * made.
43 *
44 * For integration with frontbuffer tracking code, intel_drrs_invalidate()
45 * and intel_drrs_flush() are called.
46 *
47 * DRRS can be further extended to support other internal panels and also
48 * the scenario of video playback wherein RR is set based on the rate
49 * requested by userspace.
50 */
51
52const char *intel_drrs_type_str(enum drrs_type drrs_type)
53{
54 static const char * const str[] = {
55 [DRRS_TYPE_NONE] = "none",
56 [DRRS_TYPE_STATIC] = "static",
57 [DRRS_TYPE_SEAMLESS] = "seamless",
58 };
59
60 if (drrs_type >= ARRAY_SIZE(str))
61 return "<invalid>";
62
63 return str[drrs_type];
64}
65
66static void
67intel_drrs_set_refresh_rate_pipeconf(struct intel_crtc *crtc,
68 enum drrs_refresh_rate refresh_rate)
69{
70 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
71 enum transcoder cpu_transcoder = crtc->drrs.cpu_transcoder;
72 u32 bit;
73
74 if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
75 bit = TRANSCONF_REFRESH_RATE_ALT_VLV;
76 else
77 bit = TRANSCONF_REFRESH_RATE_ALT_ILK;
78
79 intel_de_rmw(dev_priv, TRANSCONF(cpu_transcoder),
80 bit, refresh_rate == DRRS_REFRESH_RATE_LOW ? bit : 0);
81}
82
83static void
84intel_drrs_set_refresh_rate_m_n(struct intel_crtc *crtc,
85 enum drrs_refresh_rate refresh_rate)
86{
87 intel_cpu_transcoder_set_m1_n1(crtc, crtc->drrs.cpu_transcoder,
88 refresh_rate == DRRS_REFRESH_RATE_LOW ?
89 &crtc->drrs.m2_n2 : &crtc->drrs.m_n);
90}
91
92bool intel_drrs_is_active(struct intel_crtc *crtc)
93{
94 return crtc->drrs.cpu_transcoder != INVALID_TRANSCODER;
95}
96
97static void intel_drrs_set_state(struct intel_crtc *crtc,
98 enum drrs_refresh_rate refresh_rate)
99{
100 struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
101
102 if (refresh_rate == crtc->drrs.refresh_rate)
103 return;
104
105 if (intel_cpu_transcoder_has_m2_n2(dev_priv, crtc->drrs.cpu_transcoder))
106 intel_drrs_set_refresh_rate_pipeconf(crtc, refresh_rate);
107 else
108 intel_drrs_set_refresh_rate_m_n(crtc, refresh_rate);
109
110 crtc->drrs.refresh_rate = refresh_rate;
111}
112
113static void intel_drrs_schedule_work(struct intel_crtc *crtc)
114{
115 struct drm_i915_private *i915 = to_i915(crtc->base.dev);
116
117 mod_delayed_work(i915->unordered_wq, &crtc->drrs.work, msecs_to_jiffies(1000));
118}
119
120static unsigned int intel_drrs_frontbuffer_bits(const struct intel_crtc_state *crtc_state)
121{
122 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
123 struct drm_i915_private *i915 = to_i915(crtc->base.dev);
124 unsigned int frontbuffer_bits;
125
126 frontbuffer_bits = INTEL_FRONTBUFFER_ALL_MASK(crtc->pipe);
127
128 for_each_intel_crtc_in_pipe_mask(&i915->drm, crtc,
129 crtc_state->bigjoiner_pipes)
130 frontbuffer_bits |= INTEL_FRONTBUFFER_ALL_MASK(crtc->pipe);
131
132 return frontbuffer_bits;
133}
134
135/**
136 * intel_drrs_activate - activate DRRS
137 * @crtc_state: the crtc state
138 *
139 * Activates DRRS on the crtc.
140 */
141void intel_drrs_activate(const struct intel_crtc_state *crtc_state)
142{
143 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
144
145 if (!crtc_state->has_drrs)
146 return;
147
148 if (!crtc_state->hw.active)
149 return;
150
151 if (intel_crtc_is_bigjoiner_slave(crtc_state))
152 return;
153
154 mutex_lock(&crtc->drrs.mutex);
155
156 crtc->drrs.cpu_transcoder = crtc_state->cpu_transcoder;
157 crtc->drrs.m_n = crtc_state->dp_m_n;
158 crtc->drrs.m2_n2 = crtc_state->dp_m2_n2;
159 crtc->drrs.frontbuffer_bits = intel_drrs_frontbuffer_bits(crtc_state);
160 crtc->drrs.busy_frontbuffer_bits = 0;
161
162 intel_drrs_schedule_work(crtc);
163
164 mutex_unlock(&crtc->drrs.mutex);
165}
166
167/**
168 * intel_drrs_deactivate - deactivate DRRS
169 * @old_crtc_state: the old crtc state
170 *
171 * Deactivates DRRS on the crtc.
172 */
173void intel_drrs_deactivate(const struct intel_crtc_state *old_crtc_state)
174{
175 struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->uapi.crtc);
176
177 if (!old_crtc_state->has_drrs)
178 return;
179
180 if (!old_crtc_state->hw.active)
181 return;
182
183 if (intel_crtc_is_bigjoiner_slave(old_crtc_state))
184 return;
185
186 mutex_lock(&crtc->drrs.mutex);
187
188 if (intel_drrs_is_active(crtc))
189 intel_drrs_set_state(crtc, DRRS_REFRESH_RATE_HIGH);
190
191 crtc->drrs.cpu_transcoder = INVALID_TRANSCODER;
192 crtc->drrs.frontbuffer_bits = 0;
193 crtc->drrs.busy_frontbuffer_bits = 0;
194
195 mutex_unlock(&crtc->drrs.mutex);
196
197 cancel_delayed_work_sync(&crtc->drrs.work);
198}
199
200static void intel_drrs_downclock_work(struct work_struct *work)
201{
202 struct intel_crtc *crtc = container_of(work, typeof(*crtc), drrs.work.work);
203
204 mutex_lock(&crtc->drrs.mutex);
205
206 if (intel_drrs_is_active(crtc) && !crtc->drrs.busy_frontbuffer_bits)
207 intel_drrs_set_state(crtc, DRRS_REFRESH_RATE_LOW);
208
209 mutex_unlock(&crtc->drrs.mutex);
210}
211
212static void intel_drrs_frontbuffer_update(struct drm_i915_private *dev_priv,
213 unsigned int all_frontbuffer_bits,
214 bool invalidate)
215{
216 struct intel_crtc *crtc;
217
218 for_each_intel_crtc(&dev_priv->drm, crtc) {
219 unsigned int frontbuffer_bits;
220
221 mutex_lock(&crtc->drrs.mutex);
222
223 frontbuffer_bits = all_frontbuffer_bits & crtc->drrs.frontbuffer_bits;
224 if (!frontbuffer_bits) {
225 mutex_unlock(&crtc->drrs.mutex);
226 continue;
227 }
228
229 if (invalidate)
230 crtc->drrs.busy_frontbuffer_bits |= frontbuffer_bits;
231 else
232 crtc->drrs.busy_frontbuffer_bits &= ~frontbuffer_bits;
233
234 /* flush/invalidate means busy screen hence upclock */
235 intel_drrs_set_state(crtc, DRRS_REFRESH_RATE_HIGH);
236
237 /*
238 * flush also means no more activity hence schedule downclock, if all
239 * other fbs are quiescent too
240 */
241 if (!crtc->drrs.busy_frontbuffer_bits)
242 intel_drrs_schedule_work(crtc);
243 else
244 cancel_delayed_work(&crtc->drrs.work);
245
246 mutex_unlock(&crtc->drrs.mutex);
247 }
248}
249
250/**
251 * intel_drrs_invalidate - Disable Idleness DRRS
252 * @dev_priv: i915 device
253 * @frontbuffer_bits: frontbuffer plane tracking bits
254 *
255 * This function gets called everytime rendering on the given planes start.
256 * Hence DRRS needs to be Upclocked, i.e. (LOW_RR -> HIGH_RR).
257 *
258 * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
259 */
260void intel_drrs_invalidate(struct drm_i915_private *dev_priv,
261 unsigned int frontbuffer_bits)
262{
263 intel_drrs_frontbuffer_update(dev_priv, frontbuffer_bits, true);
264}
265
266/**
267 * intel_drrs_flush - Restart Idleness DRRS
268 * @dev_priv: i915 device
269 * @frontbuffer_bits: frontbuffer plane tracking bits
270 *
271 * This function gets called every time rendering on the given planes has
272 * completed or flip on a crtc is completed. So DRRS should be upclocked
273 * (LOW_RR -> HIGH_RR). And also Idleness detection should be started again,
274 * if no other planes are dirty.
275 *
276 * Dirty frontbuffers relevant to DRRS are tracked in busy_frontbuffer_bits.
277 */
278void intel_drrs_flush(struct drm_i915_private *dev_priv,
279 unsigned int frontbuffer_bits)
280{
281 intel_drrs_frontbuffer_update(dev_priv, frontbuffer_bits, false);
282}
283
284/**
285 * intel_drrs_crtc_init - Init DRRS for CRTC
286 * @crtc: crtc
287 *
288 * This function is called only once at driver load to initialize basic
289 * DRRS stuff.
290 *
291 */
292void intel_drrs_crtc_init(struct intel_crtc *crtc)
293{
294 INIT_DELAYED_WORK(&crtc->drrs.work, intel_drrs_downclock_work);
295 mutex_init(&crtc->drrs.mutex);
296 crtc->drrs.cpu_transcoder = INVALID_TRANSCODER;
297}
298
299static int intel_drrs_debugfs_status_show(struct seq_file *m, void *unused)
300{
301 struct intel_crtc *crtc = m->private;
302 const struct intel_crtc_state *crtc_state;
303 int ret;
304
305 ret = drm_modeset_lock_single_interruptible(&crtc->base.mutex);
306 if (ret)
307 return ret;
308
309 crtc_state = to_intel_crtc_state(crtc->base.state);
310
311 mutex_lock(&crtc->drrs.mutex);
312
313 seq_printf(m, "DRRS enabled: %s\n",
314 str_yes_no(crtc_state->has_drrs));
315
316 seq_printf(m, "DRRS active: %s\n",
317 str_yes_no(intel_drrs_is_active(crtc)));
318
319 seq_printf(m, "DRRS refresh rate: %s\n",
320 crtc->drrs.refresh_rate == DRRS_REFRESH_RATE_LOW ?
321 "low" : "high");
322
323 seq_printf(m, "DRRS busy frontbuffer bits: 0x%x\n",
324 crtc->drrs.busy_frontbuffer_bits);
325
326 mutex_unlock(&crtc->drrs.mutex);
327
328 drm_modeset_unlock(&crtc->base.mutex);
329
330 return 0;
331}
332
333DEFINE_SHOW_ATTRIBUTE(intel_drrs_debugfs_status);
334
335static int intel_drrs_debugfs_ctl_set(void *data, u64 val)
336{
337 struct intel_crtc *crtc = data;
338 struct drm_i915_private *i915 = to_i915(crtc->base.dev);
339 struct intel_crtc_state *crtc_state;
340 struct drm_crtc_commit *commit;
341 int ret;
342
343 ret = drm_modeset_lock_single_interruptible(&crtc->base.mutex);
344 if (ret)
345 return ret;
346
347 crtc_state = to_intel_crtc_state(crtc->base.state);
348
349 if (!crtc_state->hw.active ||
350 !crtc_state->has_drrs)
351 goto out;
352
353 commit = crtc_state->uapi.commit;
354 if (commit) {
355 ret = wait_for_completion_interruptible(&commit->hw_done);
356 if (ret)
357 goto out;
358 }
359
360 drm_dbg(&i915->drm,
361 "Manually %sactivating DRRS\n", val ? "" : "de");
362
363 if (val)
364 intel_drrs_activate(crtc_state);
365 else
366 intel_drrs_deactivate(crtc_state);
367
368out:
369 drm_modeset_unlock(&crtc->base.mutex);
370
371 return ret;
372}
373
374DEFINE_DEBUGFS_ATTRIBUTE(intel_drrs_debugfs_ctl_fops,
375 NULL, intel_drrs_debugfs_ctl_set, "%llu\n");
376
377void intel_drrs_crtc_debugfs_add(struct intel_crtc *crtc)
378{
379 debugfs_create_file("i915_drrs_status", 0444, crtc->base.debugfs_entry,
380 crtc, &intel_drrs_debugfs_status_fops);
381
382 debugfs_create_file_unsafe("i915_drrs_ctl", 0644, crtc->base.debugfs_entry,
383 crtc, &intel_drrs_debugfs_ctl_fops);
384}
385
386static int intel_drrs_debugfs_type_show(struct seq_file *m, void *unused)
387{
388 struct intel_connector *connector = m->private;
389
390 seq_printf(m, "DRRS type: %s\n",
391 intel_drrs_type_str(intel_panel_drrs_type(connector)));
392
393 return 0;
394}
395
396DEFINE_SHOW_ATTRIBUTE(intel_drrs_debugfs_type);
397
398void intel_drrs_connector_debugfs_add(struct intel_connector *connector)
399{
400 if (intel_panel_drrs_type(connector) == DRRS_TYPE_NONE)
401 return;
402
403 debugfs_create_file("i915_drrs_type", 0444, connector->base.debugfs_entry,
404 connector, &intel_drrs_debugfs_type_fops);
405}