1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2022 Intel Corporation
4 */
5
6#include "hsw_ips.h"
7#include "i915_drv.h"
8#include "i915_reg.h"
9#include "intel_color_regs.h"
10#include "intel_de.h"
11#include "intel_display_types.h"
12#include "intel_pcode.h"
13
14static void hsw_ips_enable(const struct intel_crtc_state *crtc_state)
15{
16 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
17 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
18 u32 val;
19
20 if (!crtc_state->ips_enabled)
21 return;
22
23 /*
24 * We can only enable IPS after we enable a plane and wait for a vblank
25 * This function is called from post_plane_update, which is run after
26 * a vblank wait.
27 */
28 drm_WARN_ON(&i915->drm,
29 !(crtc_state->active_planes & ~BIT(PLANE_CURSOR)));
30
31 val = IPS_ENABLE;
32
33 if (i915->display.ips.false_color)
34 val |= IPS_FALSE_COLOR;
35
36 if (IS_BROADWELL(i915)) {
37 drm_WARN_ON(&i915->drm,
38 snb_pcode_write(&i915->uncore, DISPLAY_IPS_CONTROL,
39 val | IPS_PCODE_CONTROL));
40 /*
41 * Quoting Art Runyan: "its not safe to expect any particular
42 * value in IPS_CTL bit 31 after enabling IPS through the
43 * mailbox." Moreover, the mailbox may return a bogus state,
44 * so we need to just enable it and continue on.
45 */
46 } else {
47 intel_de_write(i915, IPS_CTL, val);
48 /*
49 * The bit only becomes 1 in the next vblank, so this wait here
50 * is essentially intel_wait_for_vblank. If we don't have this
51 * and don't wait for vblanks until the end of crtc_enable, then
52 * the HW state readout code will complain that the expected
53 * IPS_CTL value is not the one we read.
54 */
55 if (intel_de_wait_for_set(i915, IPS_CTL, IPS_ENABLE, timeout: 50))
56 drm_err(&i915->drm,
57 "Timed out waiting for IPS enable\n");
58 }
59}
60
61bool hsw_ips_disable(const struct intel_crtc_state *crtc_state)
62{
63 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
64 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
65 bool need_vblank_wait = false;
66
67 if (!crtc_state->ips_enabled)
68 return need_vblank_wait;
69
70 if (IS_BROADWELL(i915)) {
71 drm_WARN_ON(&i915->drm,
72 snb_pcode_write(&i915->uncore, DISPLAY_IPS_CONTROL, 0));
73 /*
74 * Wait for PCODE to finish disabling IPS. The BSpec specified
75 * 42ms timeout value leads to occasional timeouts so use 100ms
76 * instead.
77 */
78 if (intel_de_wait_for_clear(i915, IPS_CTL, IPS_ENABLE, timeout: 100))
79 drm_err(&i915->drm,
80 "Timed out waiting for IPS disable\n");
81 } else {
82 intel_de_write(i915, IPS_CTL, val: 0);
83 intel_de_posting_read(i915, IPS_CTL);
84 }
85
86 /* We need to wait for a vblank before we can disable the plane. */
87 need_vblank_wait = true;
88
89 return need_vblank_wait;
90}
91
92static bool hsw_ips_need_disable(struct intel_atomic_state *state,
93 struct intel_crtc *crtc)
94{
95 struct drm_i915_private *i915 = to_i915(dev: state->base.dev);
96 const struct intel_crtc_state *old_crtc_state =
97 intel_atomic_get_old_crtc_state(state, crtc);
98 const struct intel_crtc_state *new_crtc_state =
99 intel_atomic_get_new_crtc_state(state, crtc);
100
101 if (!old_crtc_state->ips_enabled)
102 return false;
103
104 if (intel_crtc_needs_modeset(crtc_state: new_crtc_state))
105 return true;
106
107 /*
108 * Workaround : Do not read or write the pipe palette/gamma data while
109 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
110 *
111 * Disable IPS before we program the LUT.
112 */
113 if (IS_HASWELL(i915) &&
114 intel_crtc_needs_color_update(crtc_state: new_crtc_state) &&
115 new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
116 return true;
117
118 return !new_crtc_state->ips_enabled;
119}
120
121bool hsw_ips_pre_update(struct intel_atomic_state *state,
122 struct intel_crtc *crtc)
123{
124 const struct intel_crtc_state *old_crtc_state =
125 intel_atomic_get_old_crtc_state(state, crtc);
126
127 if (!hsw_ips_need_disable(state, crtc))
128 return false;
129
130 return hsw_ips_disable(crtc_state: old_crtc_state);
131}
132
133static bool hsw_ips_need_enable(struct intel_atomic_state *state,
134 struct intel_crtc *crtc)
135{
136 struct drm_i915_private *i915 = to_i915(dev: state->base.dev);
137 const struct intel_crtc_state *old_crtc_state =
138 intel_atomic_get_old_crtc_state(state, crtc);
139 const struct intel_crtc_state *new_crtc_state =
140 intel_atomic_get_new_crtc_state(state, crtc);
141
142 if (!new_crtc_state->ips_enabled)
143 return false;
144
145 if (intel_crtc_needs_modeset(crtc_state: new_crtc_state))
146 return true;
147
148 /*
149 * Workaround : Do not read or write the pipe palette/gamma data while
150 * GAMMA_MODE is configured for split gamma and IPS_CTL has IPS enabled.
151 *
152 * Re-enable IPS after the LUT has been programmed.
153 */
154 if (IS_HASWELL(i915) &&
155 intel_crtc_needs_color_update(crtc_state: new_crtc_state) &&
156 new_crtc_state->gamma_mode == GAMMA_MODE_MODE_SPLIT)
157 return true;
158
159 /*
160 * We can't read out IPS on broadwell, assume the worst and
161 * forcibly enable IPS on the first fastset.
162 */
163 if (intel_crtc_needs_fastset(crtc_state: new_crtc_state) && old_crtc_state->inherited)
164 return true;
165
166 return !old_crtc_state->ips_enabled;
167}
168
169void hsw_ips_post_update(struct intel_atomic_state *state,
170 struct intel_crtc *crtc)
171{
172 const struct intel_crtc_state *new_crtc_state =
173 intel_atomic_get_new_crtc_state(state, crtc);
174
175 if (!hsw_ips_need_enable(state, crtc))
176 return;
177
178 hsw_ips_enable(crtc_state: new_crtc_state);
179}
180
181/* IPS only exists on ULT machines and is tied to pipe A. */
182bool hsw_crtc_supports_ips(struct intel_crtc *crtc)
183{
184 return HAS_IPS(to_i915(crtc->base.dev)) && crtc->pipe == PIPE_A;
185}
186
187bool hsw_crtc_state_ips_capable(const struct intel_crtc_state *crtc_state)
188{
189 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
190 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
191
192 /* IPS only exists on ULT machines and is tied to pipe A. */
193 if (!hsw_crtc_supports_ips(crtc))
194 return false;
195
196 if (!i915->display.params.enable_ips)
197 return false;
198
199 if (crtc_state->pipe_bpp > 24)
200 return false;
201
202 /*
203 * We compare against max which means we must take
204 * the increased cdclk requirement into account when
205 * calculating the new cdclk.
206 *
207 * Should measure whether using a lower cdclk w/o IPS
208 */
209 if (IS_BROADWELL(i915) &&
210 crtc_state->pixel_rate > i915->display.cdclk.max_cdclk_freq * 95 / 100)
211 return false;
212
213 return true;
214}
215
216int hsw_ips_compute_config(struct intel_atomic_state *state,
217 struct intel_crtc *crtc)
218{
219 struct drm_i915_private *i915 = to_i915(dev: state->base.dev);
220 struct intel_crtc_state *crtc_state =
221 intel_atomic_get_new_crtc_state(state, crtc);
222
223 crtc_state->ips_enabled = false;
224
225 if (!hsw_crtc_state_ips_capable(crtc_state))
226 return 0;
227
228 /*
229 * When IPS gets enabled, the pipe CRC changes. Since IPS gets
230 * enabled and disabled dynamically based on package C states,
231 * user space can't make reliable use of the CRCs, so let's just
232 * completely disable it.
233 */
234 if (crtc_state->crc_enabled)
235 return 0;
236
237 /* IPS should be fine as long as at least one plane is enabled. */
238 if (!(crtc_state->active_planes & ~BIT(PLANE_CURSOR)))
239 return 0;
240
241 if (IS_BROADWELL(i915)) {
242 const struct intel_cdclk_state *cdclk_state;
243
244 cdclk_state = intel_atomic_get_cdclk_state(state);
245 if (IS_ERR(ptr: cdclk_state))
246 return PTR_ERR(ptr: cdclk_state);
247
248 /* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
249 if (crtc_state->pixel_rate > cdclk_state->logical.cdclk * 95 / 100)
250 return 0;
251 }
252
253 crtc_state->ips_enabled = true;
254
255 return 0;
256}
257
258void hsw_ips_get_config(struct intel_crtc_state *crtc_state)
259{
260 struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
261 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
262
263 if (!hsw_crtc_supports_ips(crtc))
264 return;
265
266 if (IS_HASWELL(i915)) {
267 crtc_state->ips_enabled = intel_de_read(i915, IPS_CTL) & IPS_ENABLE;
268 } else {
269 /*
270 * We cannot readout IPS state on broadwell, set to
271 * true so we can set it to a defined state on first
272 * commit.
273 */
274 crtc_state->ips_enabled = true;
275 }
276}
277
278static int hsw_ips_debugfs_false_color_get(void *data, u64 *val)
279{
280 struct intel_crtc *crtc = data;
281 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
282
283 *val = i915->display.ips.false_color;
284
285 return 0;
286}
287
288static int hsw_ips_debugfs_false_color_set(void *data, u64 val)
289{
290 struct intel_crtc *crtc = data;
291 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
292 struct intel_crtc_state *crtc_state;
293 int ret;
294
295 ret = drm_modeset_lock(lock: &crtc->base.mutex, NULL);
296 if (ret)
297 return ret;
298
299 i915->display.ips.false_color = val;
300
301 crtc_state = to_intel_crtc_state(crtc->base.state);
302
303 if (!crtc_state->hw.active)
304 goto unlock;
305
306 if (crtc_state->uapi.commit &&
307 !try_wait_for_completion(x: &crtc_state->uapi.commit->hw_done))
308 goto unlock;
309
310 hsw_ips_enable(crtc_state);
311
312 unlock:
313 drm_modeset_unlock(lock: &crtc->base.mutex);
314
315 return ret;
316}
317
318DEFINE_DEBUGFS_ATTRIBUTE(hsw_ips_debugfs_false_color_fops,
319 hsw_ips_debugfs_false_color_get,
320 hsw_ips_debugfs_false_color_set,
321 "%llu\n");
322
323static int hsw_ips_debugfs_status_show(struct seq_file *m, void *unused)
324{
325 struct intel_crtc *crtc = m->private;
326 struct drm_i915_private *i915 = to_i915(dev: crtc->base.dev);
327 intel_wakeref_t wakeref;
328
329 wakeref = intel_runtime_pm_get(rpm: &i915->runtime_pm);
330
331 seq_printf(m, fmt: "Enabled by kernel parameter: %s\n",
332 str_yes_no(v: i915->display.params.enable_ips));
333
334 if (DISPLAY_VER(i915) >= 8) {
335 seq_puts(m, s: "Currently: unknown\n");
336 } else {
337 if (intel_de_read(i915, IPS_CTL) & IPS_ENABLE)
338 seq_puts(m, s: "Currently: enabled\n");
339 else
340 seq_puts(m, s: "Currently: disabled\n");
341 }
342
343 intel_runtime_pm_put(rpm: &i915->runtime_pm, wref: wakeref);
344
345 return 0;
346}
347
348DEFINE_SHOW_ATTRIBUTE(hsw_ips_debugfs_status);
349
350void hsw_ips_crtc_debugfs_add(struct intel_crtc *crtc)
351{
352 if (!hsw_crtc_supports_ips(crtc))
353 return;
354
355 debugfs_create_file(name: "i915_ips_false_color", mode: 0644, parent: crtc->base.debugfs_entry,
356 data: crtc, fops: &hsw_ips_debugfs_false_color_fops);
357
358 debugfs_create_file(name: "i915_ips_status", mode: 0444, parent: crtc->base.debugfs_entry,
359 data: crtc, fops: &hsw_ips_debugfs_status_fops);
360}
361

source code of linux/drivers/gpu/drm/i915/display/hsw_ips.c