1 /*
2  * Copyright © 2015 Intel Corporation
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 (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  */
24 
25 /*
26  * Laptops with Intel GPUs which have panels that support controlling the
27  * backlight through DP AUX can actually use two different interfaces: Intel's
28  * proprietary DP AUX backlight interface, and the standard VESA backlight
29  * interface. Unfortunately, at the time of writing this a lot of laptops will
30  * advertise support for the standard VESA backlight interface when they
31  * don't properly support it. However, on these systems the Intel backlight
32  * interface generally does work properly. Additionally, these systems will
33  * usually just indicate that they use PWM backlight controls in their VBIOS
34  * for some reason.
35  */
36 
37 #include "intel_backlight.h"
38 #include "intel_display_types.h"
39 #include "intel_dp.h"
40 #include "intel_dp_aux_backlight.h"
41 
42 /* TODO:
43  * Implement HDR, right now we just implement the bare minimum to bring us back into SDR mode so we
44  * can make people's backlights work in the mean time
45  */
46 
47 /*
48  * DP AUX registers for Intel's proprietary HDR backlight interface. We define
49  * them here since we'll likely be the only driver to ever use these.
50  */
51 #define INTEL_EDP_HDR_TCON_CAP0                                        0x340
52 
53 #define INTEL_EDP_HDR_TCON_CAP1                                        0x341
54 # define INTEL_EDP_HDR_TCON_2084_DECODE_CAP                           BIT(0)
55 # define INTEL_EDP_HDR_TCON_2020_GAMUT_CAP                            BIT(1)
56 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_CAP                          BIT(2)
57 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_CAP                   BIT(3)
58 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP                       BIT(4)
59 # define INTEL_EDP_HDR_TCON_OPTIMIZATION_CAP                          BIT(5)
60 # define INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_CAP                       BIT(6)
61 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_CONVERSION_CAP        BIT(7)
62 
63 #define INTEL_EDP_HDR_TCON_CAP2                                        0x342
64 # define INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP                        BIT(0)
65 
66 #define INTEL_EDP_HDR_TCON_CAP3                                        0x343
67 
68 #define INTEL_EDP_HDR_GETSET_CTRL_PARAMS                               0x344
69 # define INTEL_EDP_HDR_TCON_2084_DECODE_ENABLE                        BIT(0)
70 # define INTEL_EDP_HDR_TCON_2020_GAMUT_ENABLE                         BIT(1)
71 # define INTEL_EDP_HDR_TCON_TONE_MAPPING_ENABLE                       BIT(2) /* Pre-TGL+ */
72 # define INTEL_EDP_HDR_TCON_SEGMENTED_BACKLIGHT_ENABLE                BIT(3)
73 # define INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE                     BIT(4)
74 # define INTEL_EDP_HDR_TCON_SRGB_TO_PANEL_GAMUT_ENABLE                BIT(5)
75 /* Bit 6 is reserved */
76 # define INTEL_EDP_HDR_TCON_SDP_COLORIMETRY_ENABLE                    BIT(7)
77 
78 #define INTEL_EDP_HDR_CONTENT_LUMINANCE                                0x346 /* Pre-TGL+ */
79 #define INTEL_EDP_HDR_PANEL_LUMINANCE_OVERRIDE                         0x34A
80 #define INTEL_EDP_SDR_LUMINANCE_LEVEL                                  0x352
81 #define INTEL_EDP_BRIGHTNESS_NITS_LSB                                  0x354
82 #define INTEL_EDP_BRIGHTNESS_NITS_MSB                                  0x355
83 #define INTEL_EDP_BRIGHTNESS_DELAY_FRAMES                              0x356
84 #define INTEL_EDP_BRIGHTNESS_PER_FRAME_STEPS                           0x357
85 
86 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_0                            0x358
87 # define INTEL_EDP_TCON_USAGE_MASK                             GENMASK(0, 3)
88 # define INTEL_EDP_TCON_USAGE_UNKNOWN                                    0x0
89 # define INTEL_EDP_TCON_USAGE_DESKTOP                                    0x1
90 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_MEDIA                          0x2
91 # define INTEL_EDP_TCON_USAGE_FULL_SCREEN_GAMING                         0x3
92 # define INTEL_EDP_TCON_POWER_MASK                                    BIT(4)
93 # define INTEL_EDP_TCON_POWER_DC                                    (0 << 4)
94 # define INTEL_EDP_TCON_POWER_AC                                    (1 << 4)
95 # define INTEL_EDP_TCON_OPTIMIZATION_STRENGTH_MASK             GENMASK(5, 7)
96 
97 #define INTEL_EDP_BRIGHTNESS_OPTIMIZATION_1                            0x359
98 
99 /* Intel EDP backlight callbacks */
100 static bool
101 intel_dp_aux_supports_hdr_backlight(struct intel_connector *connector)
102 {
103 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
104 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
105 	struct drm_dp_aux *aux = &intel_dp->aux;
106 	struct intel_panel *panel = &connector->panel;
107 	int ret;
108 	u8 tcon_cap[4];
109 
110 	intel_dp_wait_source_oui(intel_dp);
111 
112 	ret = drm_dp_dpcd_read(aux, INTEL_EDP_HDR_TCON_CAP0, tcon_cap, sizeof(tcon_cap));
113 	if (ret != sizeof(tcon_cap))
114 		return false;
115 
116 	if (!(tcon_cap[1] & INTEL_EDP_HDR_TCON_BRIGHTNESS_NITS_CAP))
117 		return false;
118 
119 	if (tcon_cap[0] >= 1) {
120 		drm_dbg_kms(&i915->drm, "Detected Intel HDR backlight interface version %d\n",
121 			    tcon_cap[0]);
122 	} else {
123 		drm_dbg_kms(&i915->drm, "Detected unsupported HDR backlight interface version %d\n",
124 			    tcon_cap[0]);
125 		return false;
126 	}
127 
128 	panel->backlight.edp.intel.sdr_uses_aux =
129 		tcon_cap[2] & INTEL_EDP_SDR_TCON_BRIGHTNESS_AUX_CAP;
130 
131 	return true;
132 }
133 
134 static u32
135 intel_dp_aux_hdr_get_backlight(struct intel_connector *connector, enum pipe pipe)
136 {
137 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
138 	struct intel_panel *panel = &connector->panel;
139 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
140 	u8 tmp;
141 	u8 buf[2] = { 0 };
142 
143 	if (drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &tmp) != 1) {
144 		drm_err(&i915->drm, "Failed to read current backlight mode from DPCD\n");
145 		return 0;
146 	}
147 
148 	if (!(tmp & INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE)) {
149 		if (!panel->backlight.edp.intel.sdr_uses_aux) {
150 			u32 pwm_level = panel->backlight.pwm_funcs->get(connector, pipe);
151 
152 			return intel_backlight_level_from_pwm(connector, pwm_level);
153 		}
154 
155 		/* Assume 100% brightness if backlight controls aren't enabled yet */
156 		return panel->backlight.max;
157 	}
158 
159 	if (drm_dp_dpcd_read(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf,
160 			     sizeof(buf)) != sizeof(buf)) {
161 		drm_err(&i915->drm, "Failed to read brightness from DPCD\n");
162 		return 0;
163 	}
164 
165 	return (buf[1] << 8 | buf[0]);
166 }
167 
168 static void
169 intel_dp_aux_hdr_set_aux_backlight(const struct drm_connector_state *conn_state, u32 level)
170 {
171 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
172 	struct drm_device *dev = connector->base.dev;
173 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
174 	u8 buf[4] = { 0 };
175 
176 	buf[0] = level & 0xFF;
177 	buf[1] = (level & 0xFF00) >> 8;
178 
179 	if (drm_dp_dpcd_write(&intel_dp->aux, INTEL_EDP_BRIGHTNESS_NITS_LSB, buf,
180 			      sizeof(buf)) != sizeof(buf))
181 		drm_err(dev, "Failed to write brightness level to DPCD\n");
182 }
183 
184 static void
185 intel_dp_aux_hdr_set_backlight(const struct drm_connector_state *conn_state, u32 level)
186 {
187 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
188 	struct intel_panel *panel = &connector->panel;
189 
190 	if (panel->backlight.edp.intel.sdr_uses_aux) {
191 		intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
192 	} else {
193 		const u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
194 
195 		intel_backlight_set_pwm_level(conn_state, pwm_level);
196 	}
197 }
198 
199 static void
200 intel_dp_aux_hdr_enable_backlight(const struct intel_crtc_state *crtc_state,
201 				  const struct drm_connector_state *conn_state, u32 level)
202 {
203 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
204 	struct intel_panel *panel = &connector->panel;
205 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
206 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
207 	int ret;
208 	u8 old_ctrl, ctrl;
209 
210 	intel_dp_wait_source_oui(intel_dp);
211 
212 	ret = drm_dp_dpcd_readb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, &old_ctrl);
213 	if (ret != 1) {
214 		drm_err(&i915->drm, "Failed to read current backlight control mode: %d\n", ret);
215 		return;
216 	}
217 
218 	ctrl = old_ctrl;
219 	if (panel->backlight.edp.intel.sdr_uses_aux) {
220 		ctrl |= INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE;
221 		intel_dp_aux_hdr_set_aux_backlight(conn_state, level);
222 	} else {
223 		u32 pwm_level = intel_backlight_level_to_pwm(connector, level);
224 
225 		panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level);
226 
227 		ctrl &= ~INTEL_EDP_HDR_TCON_BRIGHTNESS_AUX_ENABLE;
228 	}
229 
230 	if (ctrl != old_ctrl)
231 		if (drm_dp_dpcd_writeb(&intel_dp->aux, INTEL_EDP_HDR_GETSET_CTRL_PARAMS, ctrl) != 1)
232 			drm_err(&i915->drm, "Failed to configure DPCD brightness controls\n");
233 }
234 
235 static void
236 intel_dp_aux_hdr_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
237 {
238 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
239 	struct intel_panel *panel = &connector->panel;
240 
241 	/* Nothing to do for AUX based backlight controls */
242 	if (panel->backlight.edp.intel.sdr_uses_aux)
243 		return;
244 
245 	/* Note we want the actual pwm_level to be 0, regardless of pwm_min */
246 	panel->backlight.pwm_funcs->disable(conn_state, intel_backlight_invert_pwm_level(connector, 0));
247 }
248 
249 static int
250 intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pipe)
251 {
252 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
253 	struct intel_panel *panel = &connector->panel;
254 	int ret;
255 
256 	if (panel->backlight.edp.intel.sdr_uses_aux) {
257 		drm_dbg_kms(&i915->drm, "SDR backlight is controlled through DPCD\n");
258 	} else {
259 		drm_dbg_kms(&i915->drm, "SDR backlight is controlled through PWM\n");
260 
261 		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
262 		if (ret < 0) {
263 			drm_err(&i915->drm,
264 				"Failed to setup SDR backlight controls through PWM: %d\n", ret);
265 			return ret;
266 		}
267 	}
268 
269 	panel->backlight.max = 512;
270 	panel->backlight.min = 0;
271 	panel->backlight.level = intel_dp_aux_hdr_get_backlight(connector, pipe);
272 	panel->backlight.enabled = panel->backlight.level != 0;
273 
274 	return 0;
275 }
276 
277 /* VESA backlight callbacks */
278 static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, enum pipe unused)
279 {
280 	return connector->panel.backlight.level;
281 }
282 
283 static void
284 intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state, u32 level)
285 {
286 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
287 	struct intel_panel *panel = &connector->panel;
288 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
289 
290 	drm_edp_backlight_set_level(&intel_dp->aux, &panel->backlight.edp.vesa.info, level);
291 }
292 
293 static void
294 intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state,
295 				   const struct drm_connector_state *conn_state, u32 level)
296 {
297 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
298 	struct intel_panel *panel = &connector->panel;
299 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
300 
301 	if (!panel->backlight.edp.vesa.info.aux_enable) {
302 		u32 pwm_level = intel_backlight_invert_pwm_level(connector,
303 								 panel->backlight.pwm_level_max);
304 
305 		panel->backlight.pwm_funcs->enable(crtc_state, conn_state, pwm_level);
306 	}
307 
308 	drm_edp_backlight_enable(&intel_dp->aux, &panel->backlight.edp.vesa.info, level);
309 }
310 
311 static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state *old_conn_state,
312 						u32 level)
313 {
314 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
315 	struct intel_panel *panel = &connector->panel;
316 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
317 
318 	drm_edp_backlight_disable(&intel_dp->aux, &panel->backlight.edp.vesa.info);
319 
320 	if (!panel->backlight.edp.vesa.info.aux_enable)
321 		panel->backlight.pwm_funcs->disable(old_conn_state,
322 						    intel_backlight_invert_pwm_level(connector, 0));
323 }
324 
325 static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector, enum pipe pipe)
326 {
327 	struct intel_dp *intel_dp = intel_attached_dp(connector);
328 	struct intel_panel *panel = &connector->panel;
329 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
330 	u16 current_level;
331 	u8 current_mode;
332 	int ret;
333 
334 	ret = drm_edp_backlight_init(&intel_dp->aux, &panel->backlight.edp.vesa.info,
335 				     i915->vbt.backlight.pwm_freq_hz, intel_dp->edp_dpcd,
336 				     &current_level, &current_mode);
337 	if (ret < 0)
338 		return ret;
339 
340 	if (!panel->backlight.edp.vesa.info.aux_enable) {
341 		ret = panel->backlight.pwm_funcs->setup(connector, pipe);
342 		if (ret < 0) {
343 			drm_err(&i915->drm,
344 				"Failed to setup PWM backlight controls for eDP backlight: %d\n",
345 				ret);
346 			return ret;
347 		}
348 	}
349 	panel->backlight.max = panel->backlight.edp.vesa.info.max;
350 	panel->backlight.min = 0;
351 	if (current_mode == DP_EDP_BACKLIGHT_CONTROL_MODE_DPCD) {
352 		panel->backlight.level = current_level;
353 		panel->backlight.enabled = panel->backlight.level != 0;
354 	} else {
355 		panel->backlight.level = panel->backlight.max;
356 		panel->backlight.enabled = false;
357 	}
358 
359 	return 0;
360 }
361 
362 static bool
363 intel_dp_aux_supports_vesa_backlight(struct intel_connector *connector)
364 {
365 	struct intel_dp *intel_dp = intel_attached_dp(connector);
366 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
367 
368 	if (drm_edp_backlight_supported(intel_dp->edp_dpcd)) {
369 		drm_dbg_kms(&i915->drm, "AUX Backlight Control Supported!\n");
370 		return true;
371 	}
372 	return false;
373 }
374 
375 static const struct intel_panel_bl_funcs intel_dp_hdr_bl_funcs = {
376 	.setup = intel_dp_aux_hdr_setup_backlight,
377 	.enable = intel_dp_aux_hdr_enable_backlight,
378 	.disable = intel_dp_aux_hdr_disable_backlight,
379 	.set = intel_dp_aux_hdr_set_backlight,
380 	.get = intel_dp_aux_hdr_get_backlight,
381 };
382 
383 static const struct intel_panel_bl_funcs intel_dp_vesa_bl_funcs = {
384 	.setup = intel_dp_aux_vesa_setup_backlight,
385 	.enable = intel_dp_aux_vesa_enable_backlight,
386 	.disable = intel_dp_aux_vesa_disable_backlight,
387 	.set = intel_dp_aux_vesa_set_backlight,
388 	.get = intel_dp_aux_vesa_get_backlight,
389 };
390 
391 enum intel_dp_aux_backlight_modparam {
392 	INTEL_DP_AUX_BACKLIGHT_AUTO = -1,
393 	INTEL_DP_AUX_BACKLIGHT_OFF = 0,
394 	INTEL_DP_AUX_BACKLIGHT_ON = 1,
395 	INTEL_DP_AUX_BACKLIGHT_FORCE_VESA = 2,
396 	INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL = 3,
397 };
398 
399 int intel_dp_aux_init_backlight_funcs(struct intel_connector *connector)
400 {
401 	struct drm_device *dev = connector->base.dev;
402 	struct intel_panel *panel = &connector->panel;
403 	struct intel_dp *intel_dp = enc_to_intel_dp(connector->encoder);
404 	struct drm_i915_private *i915 = dp_to_i915(intel_dp);
405 	bool try_intel_interface = false, try_vesa_interface = false;
406 
407 	/* Check the VBT and user's module parameters to figure out which
408 	 * interfaces to probe
409 	 */
410 	switch (i915->params.enable_dpcd_backlight) {
411 	case INTEL_DP_AUX_BACKLIGHT_OFF:
412 		return -ENODEV;
413 	case INTEL_DP_AUX_BACKLIGHT_AUTO:
414 		switch (i915->vbt.backlight.type) {
415 		case INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE:
416 			try_vesa_interface = true;
417 			break;
418 		case INTEL_BACKLIGHT_DISPLAY_DDI:
419 			try_intel_interface = true;
420 			break;
421 		default:
422 			return -ENODEV;
423 		}
424 		break;
425 	case INTEL_DP_AUX_BACKLIGHT_ON:
426 		if (i915->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE)
427 			try_intel_interface = true;
428 
429 		try_vesa_interface = true;
430 		break;
431 	case INTEL_DP_AUX_BACKLIGHT_FORCE_VESA:
432 		try_vesa_interface = true;
433 		break;
434 	case INTEL_DP_AUX_BACKLIGHT_FORCE_INTEL:
435 		try_intel_interface = true;
436 		break;
437 	}
438 
439 	/*
440 	 * A lot of eDP panels in the wild will report supporting both the
441 	 * Intel proprietary backlight control interface, and the VESA
442 	 * backlight control interface. Many of these panels are liars though,
443 	 * and will only work with the Intel interface. So, always probe for
444 	 * that first.
445 	 */
446 	if (try_intel_interface && intel_dp_aux_supports_hdr_backlight(connector)) {
447 		drm_dbg_kms(dev, "Using Intel proprietary eDP backlight controls\n");
448 		panel->backlight.funcs = &intel_dp_hdr_bl_funcs;
449 		return 0;
450 	}
451 
452 	if (try_vesa_interface && intel_dp_aux_supports_vesa_backlight(connector)) {
453 		drm_dbg_kms(dev, "Using VESA eDP backlight controls\n");
454 		panel->backlight.funcs = &intel_dp_vesa_bl_funcs;
455 		return 0;
456 	}
457 
458 	return -ENODEV;
459 }
460