xref: /linux/drivers/gpu/drm/i915/display/intel_backlight.c (revision 07fdad3a93756b872da7b53647715c48d0f4a2d0)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2021 Intel Corporation
4  */
5 
6 #include <linux/backlight.h>
7 #include <linux/kernel.h>
8 #include <linux/pwm.h>
9 #include <linux/string_helpers.h>
10 #include <acpi/video.h>
11 
12 #include <drm/drm_file.h>
13 #include <drm/drm_print.h>
14 
15 #include "i915_reg.h"
16 #include "i915_utils.h"
17 #include "intel_backlight.h"
18 #include "intel_backlight_regs.h"
19 #include "intel_connector.h"
20 #include "intel_de.h"
21 #include "intel_display_regs.h"
22 #include "intel_display_rpm.h"
23 #include "intel_display_types.h"
24 #include "intel_dp_aux_backlight.h"
25 #include "intel_dsi_dcs_backlight.h"
26 #include "intel_panel.h"
27 #include "intel_pci_config.h"
28 #include "intel_pps.h"
29 #include "intel_quirks.h"
30 
31 /**
32  * scale - scale values from one range to another
33  * @source_val: value in range [@source_min..@source_max]
34  * @source_min: minimum legal value for @source_val
35  * @source_max: maximum legal value for @source_val
36  * @target_min: corresponding target value for @source_min
37  * @target_max: corresponding target value for @source_max
38  *
39  * Return @source_val in range [@source_min..@source_max] scaled to range
40  * [@target_min..@target_max].
41  */
42 static u32 scale(u32 source_val,
43 		 u32 source_min, u32 source_max,
44 		 u32 target_min, u32 target_max)
45 {
46 	u64 target_val;
47 
48 	if (WARN_ON(source_min >= source_max) ||
49 	    WARN_ON(target_min > target_max))
50 		return target_min;
51 
52 	/* defensive */
53 	source_val = clamp(source_val, source_min, source_max);
54 
55 	/* avoid overflows */
56 	target_val = mul_u32_u32(source_val - source_min,
57 				 target_max - target_min);
58 	target_val = DIV_ROUND_CLOSEST_ULL(target_val, source_max - source_min);
59 	target_val += target_min;
60 
61 	return target_val;
62 }
63 
64 /*
65  * Scale user_level in range [0..user_max] to [0..hw_max], clamping the result
66  * to [hw_min..hw_max].
67  */
68 static u32 clamp_user_to_hw(struct intel_connector *connector,
69 			    u32 user_level, u32 user_max)
70 {
71 	struct intel_panel *panel = &connector->panel;
72 	u32 hw_level;
73 
74 	hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max);
75 	hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max);
76 
77 	return hw_level;
78 }
79 
80 /* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */
81 static u32 scale_hw_to_user(struct intel_connector *connector,
82 			    u32 hw_level, u32 user_max)
83 {
84 	struct intel_panel *panel = &connector->panel;
85 
86 	return scale(hw_level, panel->backlight.min, panel->backlight.max,
87 		     0, user_max);
88 }
89 
90 u32 intel_backlight_invert_pwm_level(struct intel_connector *connector, u32 val)
91 {
92 	struct intel_display *display = to_intel_display(connector);
93 	struct intel_panel *panel = &connector->panel;
94 
95 	drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0);
96 
97 	if (display->params.invert_brightness < 0)
98 		return val;
99 
100 	if (display->params.invert_brightness > 0 ||
101 	    intel_has_quirk(display, QUIRK_INVERT_BRIGHTNESS)) {
102 		return panel->backlight.pwm_level_max - val + panel->backlight.pwm_level_min;
103 	}
104 
105 	return val;
106 }
107 
108 void intel_backlight_set_pwm_level(const struct drm_connector_state *conn_state, u32 val)
109 {
110 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
111 	struct intel_display *display = to_intel_display(connector);
112 	struct intel_panel *panel = &connector->panel;
113 
114 	drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] set backlight PWM = %d\n",
115 		    connector->base.base.id, connector->base.name, val);
116 	panel->backlight.pwm_funcs->set(conn_state, val);
117 }
118 
119 u32 intel_backlight_level_to_pwm(struct intel_connector *connector, u32 val)
120 {
121 	struct intel_display *display = to_intel_display(connector);
122 	struct intel_panel *panel = &connector->panel;
123 
124 	drm_WARN_ON_ONCE(display->drm,
125 			 panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);
126 
127 	val = scale(val, panel->backlight.min, panel->backlight.max,
128 		    panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);
129 
130 	return intel_backlight_invert_pwm_level(connector, val);
131 }
132 
133 u32 intel_backlight_level_from_pwm(struct intel_connector *connector, u32 val)
134 {
135 	struct intel_display *display = to_intel_display(connector);
136 	struct intel_panel *panel = &connector->panel;
137 
138 	drm_WARN_ON_ONCE(display->drm,
139 			 panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);
140 
141 	if (display->params.invert_brightness > 0 ||
142 	    (display->params.invert_brightness == 0 &&
143 	     intel_has_quirk(display, QUIRK_INVERT_BRIGHTNESS)))
144 		val = panel->backlight.pwm_level_max - (val - panel->backlight.pwm_level_min);
145 
146 	return scale(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max,
147 		     panel->backlight.min, panel->backlight.max);
148 }
149 
150 static u32 lpt_get_backlight(struct intel_connector *connector, enum pipe unused)
151 {
152 	struct intel_display *display = to_intel_display(connector);
153 
154 	return intel_de_read(display, BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
155 }
156 
157 static u32 pch_get_backlight(struct intel_connector *connector, enum pipe unused)
158 {
159 	struct intel_display *display = to_intel_display(connector);
160 
161 	return intel_de_read(display, BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
162 }
163 
164 static u32 i9xx_get_backlight(struct intel_connector *connector, enum pipe unused)
165 {
166 	struct intel_display *display = to_intel_display(connector);
167 	struct intel_panel *panel = &connector->panel;
168 	u32 val;
169 
170 	val = intel_de_read(display, BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
171 	if (DISPLAY_VER(display) < 4)
172 		val >>= 1;
173 
174 	if (panel->backlight.combination_mode) {
175 		struct pci_dev *pdev = to_pci_dev(display->drm->dev);
176 		u8 lbpc;
177 
178 		pci_read_config_byte(pdev, LBPC, &lbpc);
179 		val *= lbpc;
180 	}
181 
182 	return val;
183 }
184 
185 static u32 vlv_get_backlight(struct intel_connector *connector, enum pipe pipe)
186 {
187 	struct intel_display *display = to_intel_display(connector);
188 
189 	if (drm_WARN_ON(display->drm, pipe != PIPE_A && pipe != PIPE_B))
190 		return 0;
191 
192 	return intel_de_read(display, VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
193 }
194 
195 static u32 bxt_get_backlight(struct intel_connector *connector, enum pipe unused)
196 {
197 	struct intel_display *display = to_intel_display(connector);
198 	struct intel_panel *panel = &connector->panel;
199 
200 	return intel_de_read(display, BXT_BLC_PWM_DUTY(panel->backlight.controller));
201 }
202 
203 static u32 ext_pwm_get_backlight(struct intel_connector *connector, enum pipe unused)
204 {
205 	struct intel_panel *panel = &connector->panel;
206 	struct pwm_state state;
207 
208 	pwm_get_state(panel->backlight.pwm, &state);
209 	return pwm_get_relative_duty_cycle(&state, 100);
210 }
211 
212 static void lpt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
213 {
214 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
215 	struct intel_display *display = to_intel_display(connector);
216 	u32 val;
217 
218 	val = intel_de_read(display, BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
219 	intel_de_write(display, BLC_PWM_PCH_CTL2, val | level);
220 }
221 
222 static void pch_set_backlight(const struct drm_connector_state *conn_state, u32 level)
223 {
224 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
225 	struct intel_display *display = to_intel_display(connector);
226 	u32 tmp;
227 
228 	tmp = intel_de_read(display, BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
229 	intel_de_write(display, BLC_PWM_CPU_CTL, tmp | level);
230 }
231 
232 static void i9xx_set_backlight(const struct drm_connector_state *conn_state, u32 level)
233 {
234 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
235 	struct intel_display *display = to_intel_display(connector);
236 	struct intel_panel *panel = &connector->panel;
237 	u32 tmp, mask;
238 
239 	if (drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0))
240 		return;
241 
242 	if (panel->backlight.combination_mode) {
243 		struct pci_dev *pdev = to_pci_dev(display->drm->dev);
244 		u8 lbpc;
245 
246 		lbpc = level * 0xfe / panel->backlight.pwm_level_max + 1;
247 		level /= lbpc;
248 		pci_write_config_byte(pdev, LBPC, lbpc);
249 	}
250 
251 	if (DISPLAY_VER(display) == 4) {
252 		mask = BACKLIGHT_DUTY_CYCLE_MASK;
253 	} else {
254 		level <<= 1;
255 		mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
256 	}
257 
258 	tmp = intel_de_read(display, BLC_PWM_CTL) & ~mask;
259 	intel_de_write(display, BLC_PWM_CTL, tmp | level);
260 }
261 
262 static void vlv_set_backlight(const struct drm_connector_state *conn_state, u32 level)
263 {
264 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
265 	struct intel_display *display = to_intel_display(connector);
266 	enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
267 	u32 tmp;
268 
269 	tmp = intel_de_read(display, VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
270 	intel_de_write(display, VLV_BLC_PWM_CTL(pipe), tmp | level);
271 }
272 
273 static void bxt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
274 {
275 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
276 	struct intel_display *display = to_intel_display(connector);
277 	struct intel_panel *panel = &connector->panel;
278 
279 	intel_de_write(display, BXT_BLC_PWM_DUTY(panel->backlight.controller), level);
280 }
281 
282 static void ext_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
283 {
284 	struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
285 
286 	pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
287 	pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
288 }
289 
290 static void
291 intel_panel_actually_set_backlight(const struct drm_connector_state *conn_state, u32 level)
292 {
293 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
294 	struct intel_display *display = to_intel_display(connector);
295 	struct intel_panel *panel = &connector->panel;
296 
297 	drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] set backlight level = %d\n",
298 		    connector->base.base.id, connector->base.name, level);
299 
300 	panel->backlight.funcs->set(conn_state, level);
301 }
302 
303 /* set backlight brightness to level in range [0..max], assuming hw min is
304  * respected.
305  */
306 void intel_backlight_set_acpi(const struct drm_connector_state *conn_state,
307 			      u32 user_level, u32 user_max)
308 {
309 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
310 	struct intel_display *display = to_intel_display(connector);
311 	struct intel_panel *panel = &connector->panel;
312 	u32 hw_level;
313 
314 	/*
315 	 * Lack of crtc may occur during driver init because
316 	 * connection_mutex isn't held across the entire backlight
317 	 * setup + modeset readout, and the BIOS can issue the
318 	 * requests at any time.
319 	 */
320 	if (!panel->backlight.present || !conn_state->crtc)
321 		return;
322 
323 	mutex_lock(&display->backlight.lock);
324 
325 	drm_WARN_ON(display->drm, panel->backlight.max == 0);
326 
327 	hw_level = clamp_user_to_hw(connector, user_level, user_max);
328 	panel->backlight.level = hw_level;
329 
330 	if (panel->backlight.device)
331 		panel->backlight.device->props.brightness =
332 			scale_hw_to_user(connector,
333 					 panel->backlight.level,
334 					 panel->backlight.device->props.max_brightness);
335 
336 	if (panel->backlight.enabled)
337 		intel_panel_actually_set_backlight(conn_state, hw_level);
338 
339 	mutex_unlock(&display->backlight.lock);
340 }
341 
342 static void lpt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
343 {
344 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
345 	struct intel_display *display = to_intel_display(connector);
346 	u32 tmp;
347 
348 	intel_backlight_set_pwm_level(old_conn_state, level);
349 
350 	/*
351 	 * Although we don't support or enable CPU PWM with LPT/SPT based
352 	 * systems, it may have been enabled prior to loading the
353 	 * driver. Disable to avoid warnings on LCPLL disable.
354 	 *
355 	 * This needs rework if we need to add support for CPU PWM on PCH split
356 	 * platforms.
357 	 */
358 	tmp = intel_de_read(display, BLC_PWM_CPU_CTL2);
359 	if (tmp & BLM_PWM_ENABLE) {
360 		drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] CPU backlight was enabled, disabling\n",
361 			    connector->base.base.id, connector->base.name);
362 		intel_de_write(display, BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
363 	}
364 
365 	intel_de_rmw(display, BLC_PWM_PCH_CTL1, BLM_PCH_PWM_ENABLE, 0);
366 }
367 
368 static void pch_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
369 {
370 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
371 	struct intel_display *display = to_intel_display(connector);
372 
373 	intel_backlight_set_pwm_level(old_conn_state, val);
374 
375 	intel_de_rmw(display, BLC_PWM_CPU_CTL2, BLM_PWM_ENABLE, 0);
376 
377 	intel_de_rmw(display, BLC_PWM_PCH_CTL1, BLM_PCH_PWM_ENABLE, 0);
378 }
379 
380 static void i9xx_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
381 {
382 	intel_backlight_set_pwm_level(old_conn_state, val);
383 }
384 
385 static void i965_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
386 {
387 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
388 	struct intel_display *display = to_intel_display(connector);
389 
390 	intel_backlight_set_pwm_level(old_conn_state, val);
391 
392 	intel_de_rmw(display, BLC_PWM_CTL2, BLM_PWM_ENABLE, 0);
393 }
394 
395 static void vlv_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
396 {
397 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
398 	struct intel_display *display = to_intel_display(connector);
399 	enum pipe pipe = to_intel_crtc(old_conn_state->crtc)->pipe;
400 
401 	intel_backlight_set_pwm_level(old_conn_state, val);
402 
403 	intel_de_rmw(display, VLV_BLC_PWM_CTL2(pipe), BLM_PWM_ENABLE, 0);
404 }
405 
406 static void bxt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
407 {
408 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
409 	struct intel_display *display = to_intel_display(connector);
410 	struct intel_panel *panel = &connector->panel;
411 
412 	intel_backlight_set_pwm_level(old_conn_state, val);
413 
414 	intel_de_rmw(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
415 		     BXT_BLC_PWM_ENABLE, 0);
416 
417 	if (panel->backlight.controller == 1)
418 		intel_de_rmw(display, UTIL_PIN_CTL, UTIL_PIN_ENABLE, 0);
419 }
420 
421 static void cnp_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
422 {
423 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
424 	struct intel_display *display = to_intel_display(connector);
425 	struct intel_panel *panel = &connector->panel;
426 
427 	intel_backlight_set_pwm_level(old_conn_state, val);
428 
429 	intel_de_rmw(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
430 		     BXT_BLC_PWM_ENABLE, 0);
431 }
432 
433 static void ext_pwm_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
434 {
435 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
436 	struct intel_panel *panel = &connector->panel;
437 
438 	intel_backlight_set_pwm_level(old_conn_state, level);
439 
440 	panel->backlight.pwm_state.enabled = false;
441 	pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
442 }
443 
444 void intel_backlight_disable(const struct drm_connector_state *old_conn_state)
445 {
446 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
447 	struct intel_display *display = to_intel_display(connector);
448 	struct intel_panel *panel = &connector->panel;
449 
450 	if (!panel->backlight.present)
451 		return;
452 
453 	/*
454 	 * Do not disable backlight on the vga_switcheroo path. When switching
455 	 * away from i915, the other client may depend on i915 to handle the
456 	 * backlight. This will leave the backlight on unnecessarily when
457 	 * another client is not activated.
458 	 */
459 	if (display->drm->switch_power_state == DRM_SWITCH_POWER_CHANGING) {
460 		drm_dbg_kms(display->drm, "[CONNECTOR:%d:%s] Skipping backlight disable on vga switch\n",
461 			    connector->base.base.id, connector->base.name);
462 		return;
463 	}
464 
465 	mutex_lock(&display->backlight.lock);
466 
467 	if (panel->backlight.device)
468 		panel->backlight.device->props.power = BACKLIGHT_POWER_OFF;
469 	panel->backlight.enabled = false;
470 	panel->backlight.funcs->disable(old_conn_state, 0);
471 
472 	mutex_unlock(&display->backlight.lock);
473 }
474 
475 static void lpt_enable_backlight(const struct intel_crtc_state *crtc_state,
476 				 const struct drm_connector_state *conn_state, u32 level)
477 {
478 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
479 	struct intel_display *display = to_intel_display(connector);
480 	struct intel_panel *panel = &connector->panel;
481 	u32 pch_ctl1, pch_ctl2;
482 
483 	pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
484 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
485 		drm_dbg_kms(display->drm,
486 			    "[CONNECTOR:%d:%s] PCH backlight already enabled\n",
487 			    connector->base.base.id, connector->base.name);
488 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
489 		intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
490 	}
491 
492 	if (HAS_PCH_LPT(display))
493 		intel_de_rmw(display, SOUTH_CHICKEN2, LPT_PWM_GRANULARITY,
494 			     panel->backlight.alternate_pwm_increment ?
495 			     LPT_PWM_GRANULARITY : 0);
496 	else
497 		intel_de_rmw(display, SOUTH_CHICKEN1, SPT_PWM_GRANULARITY,
498 			     panel->backlight.alternate_pwm_increment ?
499 			     SPT_PWM_GRANULARITY : 0);
500 
501 	pch_ctl2 = panel->backlight.pwm_level_max << 16;
502 	intel_de_write(display, BLC_PWM_PCH_CTL2, pch_ctl2);
503 
504 	pch_ctl1 = 0;
505 	if (panel->backlight.active_low_pwm)
506 		pch_ctl1 |= BLM_PCH_POLARITY;
507 
508 	/* After LPT, override is the default. */
509 	if (HAS_PCH_LPT(display))
510 		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
511 
512 	intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
513 	intel_de_posting_read(display, BLC_PWM_PCH_CTL1);
514 	intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
515 
516 	/* This won't stick until the above enable. */
517 	intel_backlight_set_pwm_level(conn_state, level);
518 }
519 
520 static void pch_enable_backlight(const struct intel_crtc_state *crtc_state,
521 				 const struct drm_connector_state *conn_state, u32 level)
522 {
523 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
524 	struct intel_display *display = to_intel_display(connector);
525 	struct intel_panel *panel = &connector->panel;
526 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
527 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
528 
529 	cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);
530 	if (cpu_ctl2 & BLM_PWM_ENABLE) {
531 		drm_dbg_kms(display->drm,
532 			    "[CONNECTOR:%d:%s] CPU backlight already enabled\n",
533 			    connector->base.base.id, connector->base.name);
534 		cpu_ctl2 &= ~BLM_PWM_ENABLE;
535 		intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2);
536 	}
537 
538 	pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
539 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
540 		drm_dbg_kms(display->drm,
541 			    "[CONNECTOR:%d:%s] PCH backlight already enabled\n",
542 			    connector->base.base.id, connector->base.name);
543 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
544 		intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
545 	}
546 
547 	if (cpu_transcoder == TRANSCODER_EDP)
548 		cpu_ctl2 = BLM_TRANSCODER_EDP;
549 	else
550 		cpu_ctl2 = BLM_PIPE(cpu_transcoder);
551 	intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2);
552 	intel_de_posting_read(display, BLC_PWM_CPU_CTL2);
553 	intel_de_write(display, BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);
554 
555 	/* This won't stick until the above enable. */
556 	intel_backlight_set_pwm_level(conn_state, level);
557 
558 	pch_ctl2 = panel->backlight.pwm_level_max << 16;
559 	intel_de_write(display, BLC_PWM_PCH_CTL2, pch_ctl2);
560 
561 	pch_ctl1 = 0;
562 	if (panel->backlight.active_low_pwm)
563 		pch_ctl1 |= BLM_PCH_POLARITY;
564 
565 	intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1);
566 	intel_de_posting_read(display, BLC_PWM_PCH_CTL1);
567 	intel_de_write(display, BLC_PWM_PCH_CTL1, pch_ctl1 | BLM_PCH_PWM_ENABLE);
568 }
569 
570 static void i9xx_enable_backlight(const struct intel_crtc_state *crtc_state,
571 				  const struct drm_connector_state *conn_state, u32 level)
572 {
573 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
574 	struct intel_display *display = to_intel_display(connector);
575 	struct intel_panel *panel = &connector->panel;
576 	u32 ctl, freq;
577 
578 	ctl = intel_de_read(display, BLC_PWM_CTL);
579 	if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
580 		drm_dbg_kms(display->drm,
581 			    "[CONNECTOR:%d:%s] backlight already enabled\n",
582 			    connector->base.base.id, connector->base.name);
583 		intel_de_write(display, BLC_PWM_CTL, 0);
584 	}
585 
586 	freq = panel->backlight.pwm_level_max;
587 	if (panel->backlight.combination_mode)
588 		freq /= 0xff;
589 
590 	ctl = freq << 17;
591 	if (panel->backlight.combination_mode)
592 		ctl |= BLM_LEGACY_MODE;
593 	if (display->platform.pineview && panel->backlight.active_low_pwm)
594 		ctl |= BLM_POLARITY_PNV;
595 
596 	intel_de_write(display, BLC_PWM_CTL, ctl);
597 	intel_de_posting_read(display, BLC_PWM_CTL);
598 
599 	/* XXX: combine this into above write? */
600 	intel_backlight_set_pwm_level(conn_state, level);
601 
602 	/*
603 	 * Needed to enable backlight on some 855gm models. BLC_HIST_CTL is
604 	 * 855gm only, but checking for gen2 is safe, as 855gm is the only gen2
605 	 * that has backlight.
606 	 */
607 	if (DISPLAY_VER(display) == 2)
608 		intel_de_write(display, BLC_HIST_CTL, BLM_HISTOGRAM_ENABLE);
609 }
610 
611 static void i965_enable_backlight(const struct intel_crtc_state *crtc_state,
612 				  const struct drm_connector_state *conn_state, u32 level)
613 {
614 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
615 	struct intel_display *display = to_intel_display(connector);
616 	struct intel_panel *panel = &connector->panel;
617 	enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
618 	u32 ctl, ctl2, freq;
619 
620 	ctl2 = intel_de_read(display, BLC_PWM_CTL2);
621 	if (ctl2 & BLM_PWM_ENABLE) {
622 		drm_dbg_kms(display->drm,
623 			    "[CONNECTOR:%d:%s] backlight already enabled\n",
624 			    connector->base.base.id, connector->base.name);
625 		ctl2 &= ~BLM_PWM_ENABLE;
626 		intel_de_write(display, BLC_PWM_CTL2, ctl2);
627 	}
628 
629 	freq = panel->backlight.pwm_level_max;
630 	if (panel->backlight.combination_mode)
631 		freq /= 0xff;
632 
633 	ctl = freq << 16;
634 	intel_de_write(display, BLC_PWM_CTL, ctl);
635 
636 	ctl2 = BLM_PIPE(pipe);
637 	if (panel->backlight.combination_mode)
638 		ctl2 |= BLM_COMBINATION_MODE;
639 	if (panel->backlight.active_low_pwm)
640 		ctl2 |= BLM_POLARITY_I965;
641 	intel_de_write(display, BLC_PWM_CTL2, ctl2);
642 	intel_de_posting_read(display, BLC_PWM_CTL2);
643 	intel_de_write(display, BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);
644 
645 	intel_backlight_set_pwm_level(conn_state, level);
646 }
647 
648 static void vlv_enable_backlight(const struct intel_crtc_state *crtc_state,
649 				 const struct drm_connector_state *conn_state, u32 level)
650 {
651 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
652 	struct intel_display *display = to_intel_display(connector);
653 	struct intel_panel *panel = &connector->panel;
654 	enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
655 	u32 ctl, ctl2;
656 
657 	ctl2 = intel_de_read(display, VLV_BLC_PWM_CTL2(pipe));
658 	if (ctl2 & BLM_PWM_ENABLE) {
659 		drm_dbg_kms(display->drm,
660 			    "[CONNECTOR:%d:%s] backlight already enabled\n",
661 			    connector->base.base.id, connector->base.name);
662 		ctl2 &= ~BLM_PWM_ENABLE;
663 		intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2);
664 	}
665 
666 	ctl = panel->backlight.pwm_level_max << 16;
667 	intel_de_write(display, VLV_BLC_PWM_CTL(pipe), ctl);
668 
669 	/* XXX: combine this into above write? */
670 	intel_backlight_set_pwm_level(conn_state, level);
671 
672 	ctl2 = 0;
673 	if (panel->backlight.active_low_pwm)
674 		ctl2 |= BLM_POLARITY_I965;
675 	intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2);
676 	intel_de_posting_read(display, VLV_BLC_PWM_CTL2(pipe));
677 	intel_de_write(display, VLV_BLC_PWM_CTL2(pipe), ctl2 | BLM_PWM_ENABLE);
678 }
679 
680 static void bxt_enable_backlight(const struct intel_crtc_state *crtc_state,
681 				 const struct drm_connector_state *conn_state, u32 level)
682 {
683 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
684 	struct intel_display *display = to_intel_display(connector);
685 	struct intel_panel *panel = &connector->panel;
686 	enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
687 	u32 pwm_ctl, val;
688 
689 	/* Controller 1 uses the utility pin. */
690 	if (panel->backlight.controller == 1) {
691 		val = intel_de_read(display, UTIL_PIN_CTL);
692 		if (val & UTIL_PIN_ENABLE) {
693 			drm_dbg_kms(display->drm,
694 				    "[CONNECTOR:%d:%s] utility pin already enabled\n",
695 				    connector->base.base.id, connector->base.name);
696 			val &= ~UTIL_PIN_ENABLE;
697 			intel_de_write(display, UTIL_PIN_CTL, val);
698 		}
699 
700 		val = 0;
701 		if (panel->backlight.util_pin_active_low)
702 			val |= UTIL_PIN_POLARITY;
703 		intel_de_write(display, UTIL_PIN_CTL,
704 			       val | UTIL_PIN_PIPE(pipe) | UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
705 	}
706 
707 	pwm_ctl = intel_de_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
708 	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
709 		drm_dbg_kms(display->drm,
710 			    "[CONNECTOR:%d:%s] backlight already enabled\n",
711 			    connector->base.base.id, connector->base.name);
712 		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
713 		intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
714 			       pwm_ctl);
715 	}
716 
717 	intel_de_write(display, BXT_BLC_PWM_FREQ(panel->backlight.controller),
718 		       panel->backlight.pwm_level_max);
719 
720 	intel_backlight_set_pwm_level(conn_state, level);
721 
722 	pwm_ctl = 0;
723 	if (panel->backlight.active_low_pwm)
724 		pwm_ctl |= BXT_BLC_PWM_POLARITY;
725 
726 	intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
727 	intel_de_posting_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
728 	intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
729 		       pwm_ctl | BXT_BLC_PWM_ENABLE);
730 }
731 
732 static void cnp_enable_backlight(const struct intel_crtc_state *crtc_state,
733 				 const struct drm_connector_state *conn_state, u32 level)
734 {
735 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
736 	struct intel_display *display = to_intel_display(connector);
737 	struct intel_panel *panel = &connector->panel;
738 	u32 pwm_ctl;
739 
740 	pwm_ctl = intel_de_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
741 	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
742 		drm_dbg_kms(display->drm, "backlight already enabled\n");
743 		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
744 		intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
745 			       pwm_ctl);
746 	}
747 
748 	intel_de_write(display, BXT_BLC_PWM_FREQ(panel->backlight.controller),
749 		       panel->backlight.pwm_level_max);
750 
751 	intel_backlight_set_pwm_level(conn_state, level);
752 
753 	pwm_ctl = 0;
754 	if (panel->backlight.active_low_pwm)
755 		pwm_ctl |= BXT_BLC_PWM_POLARITY;
756 
757 	intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller), pwm_ctl);
758 	intel_de_posting_read(display, BXT_BLC_PWM_CTL(panel->backlight.controller));
759 	intel_de_write(display, BXT_BLC_PWM_CTL(panel->backlight.controller),
760 		       pwm_ctl | BXT_BLC_PWM_ENABLE);
761 }
762 
763 static void ext_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
764 				     const struct drm_connector_state *conn_state, u32 level)
765 {
766 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
767 	struct intel_panel *panel = &connector->panel;
768 
769 	pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
770 	panel->backlight.pwm_state.enabled = true;
771 	pwm_apply_might_sleep(panel->backlight.pwm, &panel->backlight.pwm_state);
772 }
773 
774 static void __intel_backlight_enable(const struct intel_crtc_state *crtc_state,
775 				     const struct drm_connector_state *conn_state)
776 {
777 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
778 	struct intel_panel *panel = &connector->panel;
779 
780 	WARN_ON(panel->backlight.max == 0);
781 
782 	if (panel->backlight.level < panel->backlight.min) {
783 		panel->backlight.level = panel->backlight.min;
784 		if (panel->backlight.device)
785 			panel->backlight.device->props.brightness =
786 				scale_hw_to_user(connector,
787 						 panel->backlight.level,
788 						 panel->backlight.device->props.max_brightness);
789 	}
790 
791 	panel->backlight.funcs->enable(crtc_state, conn_state, panel->backlight.level);
792 	panel->backlight.enabled = true;
793 	if (panel->backlight.device)
794 		panel->backlight.device->props.power = BACKLIGHT_POWER_ON;
795 }
796 
797 void intel_backlight_enable(const struct intel_crtc_state *crtc_state,
798 			    const struct drm_connector_state *conn_state)
799 {
800 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
801 	struct intel_display *display = to_intel_display(connector);
802 	struct intel_panel *panel = &connector->panel;
803 	enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
804 
805 	if (!panel->backlight.present)
806 		return;
807 
808 	drm_dbg_kms(display->drm, "pipe %c\n", pipe_name(pipe));
809 
810 	mutex_lock(&display->backlight.lock);
811 
812 	__intel_backlight_enable(crtc_state, conn_state);
813 
814 	mutex_unlock(&display->backlight.lock);
815 }
816 
817 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
818 static u32 intel_panel_get_backlight(struct intel_connector *connector)
819 {
820 	struct intel_display *display = to_intel_display(connector);
821 	struct intel_panel *panel = &connector->panel;
822 	u32 val = 0;
823 
824 	mutex_lock(&display->backlight.lock);
825 
826 	if (panel->backlight.enabled)
827 		val = panel->backlight.funcs->get(connector, intel_connector_get_pipe(connector));
828 
829 	mutex_unlock(&display->backlight.lock);
830 
831 	drm_dbg_kms(display->drm, "get backlight PWM = %d\n", val);
832 	return val;
833 }
834 
835 /* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */
836 static u32 scale_user_to_hw(struct intel_connector *connector,
837 			    u32 user_level, u32 user_max)
838 {
839 	struct intel_panel *panel = &connector->panel;
840 
841 	return scale(user_level, 0, user_max,
842 		     panel->backlight.min, panel->backlight.max);
843 }
844 
845 /* set backlight brightness to level in range [0..max], scaling wrt hw min */
846 static void intel_panel_set_backlight(const struct drm_connector_state *conn_state,
847 				      u32 user_level, u32 user_max)
848 {
849 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
850 	struct intel_display *display = to_intel_display(connector);
851 	struct intel_panel *panel = &connector->panel;
852 	u32 hw_level;
853 
854 	if (!panel->backlight.present)
855 		return;
856 
857 	mutex_lock(&display->backlight.lock);
858 
859 	drm_WARN_ON(display->drm, panel->backlight.max == 0);
860 
861 	hw_level = scale_user_to_hw(connector, user_level, user_max);
862 	panel->backlight.level = hw_level;
863 
864 	if (panel->backlight.enabled)
865 		intel_panel_actually_set_backlight(conn_state, hw_level);
866 
867 	mutex_unlock(&display->backlight.lock);
868 }
869 
870 static int intel_backlight_device_update_status(struct backlight_device *bd)
871 {
872 	struct intel_connector *connector = bl_get_data(bd);
873 	struct intel_display *display = to_intel_display(connector);
874 	struct intel_panel *panel = &connector->panel;
875 
876 	drm_modeset_lock(&display->drm->mode_config.connection_mutex, NULL);
877 
878 	drm_dbg_kms(display->drm, "updating intel_backlight, brightness=%d/%d\n",
879 		    bd->props.brightness, bd->props.max_brightness);
880 	intel_panel_set_backlight(connector->base.state, bd->props.brightness,
881 				  bd->props.max_brightness);
882 
883 	/*
884 	 * Allow flipping bl_power as a sub-state of enabled. Sadly the
885 	 * backlight class device does not make it easy to differentiate
886 	 * between callbacks for brightness and bl_power, so our backlight_power
887 	 * callback needs to take this into account.
888 	 */
889 	if (panel->backlight.enabled) {
890 		if (panel->backlight.power) {
891 			bool enable = bd->props.power == BACKLIGHT_POWER_ON &&
892 				bd->props.brightness != 0;
893 			panel->backlight.power(connector, enable);
894 		}
895 	} else {
896 		bd->props.power = BACKLIGHT_POWER_OFF;
897 	}
898 
899 	drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
900 
901 	return 0;
902 }
903 
904 static int intel_backlight_device_get_brightness(struct backlight_device *bd)
905 {
906 	struct intel_connector *connector = bl_get_data(bd);
907 	struct intel_display *display = to_intel_display(connector);
908 	int ret = 0;
909 
910 	with_intel_display_rpm(display) {
911 		u32 hw_level;
912 
913 		drm_modeset_lock(&display->drm->mode_config.connection_mutex, NULL);
914 
915 		hw_level = intel_panel_get_backlight(connector);
916 		ret = scale_hw_to_user(connector,
917 				       hw_level, bd->props.max_brightness);
918 
919 		drm_modeset_unlock(&display->drm->mode_config.connection_mutex);
920 	}
921 
922 	return ret;
923 }
924 
925 static const struct backlight_ops intel_backlight_device_ops = {
926 	.update_status = intel_backlight_device_update_status,
927 	.get_brightness = intel_backlight_device_get_brightness,
928 };
929 
930 int intel_backlight_device_register(struct intel_connector *connector)
931 {
932 	struct intel_display *display = to_intel_display(connector);
933 	struct intel_panel *panel = &connector->panel;
934 	struct backlight_properties props;
935 	struct backlight_device *bd;
936 	const char *name;
937 	int ret = 0;
938 
939 	if (WARN_ON(panel->backlight.device))
940 		return -ENODEV;
941 
942 	if (!panel->backlight.present)
943 		return 0;
944 
945 	WARN_ON(panel->backlight.max == 0);
946 
947 	if (!acpi_video_backlight_use_native()) {
948 		drm_info(display->drm,
949 			 "Skipping intel_backlight registration\n");
950 		return 0;
951 	}
952 
953 	memset(&props, 0, sizeof(props));
954 	props.type = BACKLIGHT_RAW;
955 
956 	/*
957 	 * Note: Everything should work even if the backlight device max
958 	 * presented to the userspace is arbitrarily chosen.
959 	 */
960 	props.max_brightness = panel->backlight.max;
961 	props.brightness = scale_hw_to_user(connector,
962 					    panel->backlight.level,
963 					    props.max_brightness);
964 
965 	if (panel->backlight.enabled)
966 		props.power = BACKLIGHT_POWER_ON;
967 	else
968 		props.power = BACKLIGHT_POWER_OFF;
969 
970 	name = kstrdup("intel_backlight", GFP_KERNEL);
971 	if (!name)
972 		return -ENOMEM;
973 
974 	bd = backlight_device_get_by_name(name);
975 	if (bd) {
976 		put_device(&bd->dev);
977 		/*
978 		 * Using the same name independent of the drm device or connector
979 		 * prevents registration of multiple backlight devices in the
980 		 * driver. However, we need to use the default name for backward
981 		 * compatibility. Use unique names for subsequent backlight devices as a
982 		 * fallback when the default name already exists.
983 		 */
984 		kfree(name);
985 		name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
986 				 display->drm->primary->index,
987 				 connector->base.name);
988 		if (!name)
989 			return -ENOMEM;
990 	}
991 	bd = backlight_device_register(name, connector->base.kdev, connector,
992 				       &intel_backlight_device_ops, &props);
993 
994 	if (IS_ERR(bd)) {
995 		drm_err(display->drm,
996 			"[CONNECTOR:%d:%s] backlight device %s register failed: %ld\n",
997 			connector->base.base.id, connector->base.name, name, PTR_ERR(bd));
998 		ret = PTR_ERR(bd);
999 		goto out;
1000 	}
1001 
1002 	panel->backlight.device = bd;
1003 
1004 	drm_dbg_kms(display->drm,
1005 		    "[CONNECTOR:%d:%s] backlight device %s registered\n",
1006 		    connector->base.base.id, connector->base.name, name);
1007 
1008 out:
1009 	kfree(name);
1010 
1011 	return ret;
1012 }
1013 
1014 void intel_backlight_device_unregister(struct intel_connector *connector)
1015 {
1016 	struct intel_panel *panel = &connector->panel;
1017 
1018 	if (panel->backlight.device) {
1019 		backlight_device_unregister(panel->backlight.device);
1020 		panel->backlight.device = NULL;
1021 	}
1022 }
1023 #endif /* CONFIG_BACKLIGHT_CLASS_DEVICE */
1024 
1025 /*
1026  * CNP: PWM clock frequency is 19.2 MHz or 24 MHz.
1027  *      PWM increment = 1
1028  */
1029 static u32 cnp_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1030 {
1031 	struct intel_display *display = to_intel_display(connector);
1032 
1033 	return DIV_ROUND_CLOSEST(KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq),
1034 				 pwm_freq_hz);
1035 }
1036 
1037 /*
1038  * BXT: PWM clock frequency = 19.2 MHz.
1039  */
1040 static u32 bxt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1041 {
1042 	return DIV_ROUND_CLOSEST(KHz(19200), pwm_freq_hz);
1043 }
1044 
1045 /*
1046  * SPT: This value represents the period of the PWM stream in clock periods
1047  * multiplied by 16 (default increment) or 128 (alternate increment selected in
1048  * SCHICKEN_1 bit 0). PWM clock is 24 MHz.
1049  */
1050 static u32 spt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1051 {
1052 	struct intel_panel *panel = &connector->panel;
1053 	u32 mul;
1054 
1055 	if (panel->backlight.alternate_pwm_increment)
1056 		mul = 128;
1057 	else
1058 		mul = 16;
1059 
1060 	return DIV_ROUND_CLOSEST(MHz(24), pwm_freq_hz * mul);
1061 }
1062 
1063 /*
1064  * LPT: This value represents the period of the PWM stream in clock periods
1065  * multiplied by 128 (default increment) or 16 (alternate increment, selected in
1066  * LPT SOUTH_CHICKEN2 register bit 5).
1067  */
1068 static u32 lpt_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1069 {
1070 	struct intel_display *display = to_intel_display(connector);
1071 	struct intel_panel *panel = &connector->panel;
1072 	u32 mul, clock;
1073 
1074 	if (panel->backlight.alternate_pwm_increment)
1075 		mul = 16;
1076 	else
1077 		mul = 128;
1078 
1079 	if (HAS_PCH_LPT_H(display))
1080 		clock = MHz(135); /* LPT:H */
1081 	else
1082 		clock = MHz(24); /* LPT:LP */
1083 
1084 	return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
1085 }
1086 
1087 /*
1088  * ILK/SNB/IVB: This value represents the period of the PWM stream in PCH
1089  * display raw clocks multiplied by 128.
1090  */
1091 static u32 pch_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1092 {
1093 	struct intel_display *display = to_intel_display(connector);
1094 
1095 	return DIV_ROUND_CLOSEST(KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq),
1096 				 pwm_freq_hz * 128);
1097 }
1098 
1099 /*
1100  * Gen2: This field determines the number of time base events (display core
1101  * clock frequency/32) in total for a complete cycle of modulated backlight
1102  * control.
1103  *
1104  * Gen3: A time base event equals the display core clock ([DevPNV] HRAW clock)
1105  * divided by 32.
1106  */
1107 static u32 i9xx_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1108 {
1109 	struct intel_display *display = to_intel_display(connector);
1110 	int clock;
1111 
1112 	if (display->platform.pineview)
1113 		clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
1114 	else
1115 		clock = KHz(display->cdclk.hw.cdclk);
1116 
1117 	return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 32);
1118 }
1119 
1120 /*
1121  * Gen4: This value represents the period of the PWM stream in display core
1122  * clocks ([DevCTG] HRAW clocks) multiplied by 128.
1123  *
1124  */
1125 static u32 i965_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1126 {
1127 	struct intel_display *display = to_intel_display(connector);
1128 	int clock;
1129 
1130 	if (display->platform.g4x)
1131 		clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
1132 	else
1133 		clock = KHz(display->cdclk.hw.cdclk);
1134 
1135 	return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * 128);
1136 }
1137 
1138 /*
1139  * VLV: This value represents the period of the PWM stream in display core
1140  * clocks ([DevCTG] 200MHz HRAW clocks) multiplied by 128 or 25MHz S0IX clocks
1141  * multiplied by 16. CHV uses a 19.2MHz S0IX clock.
1142  */
1143 static u32 vlv_hz_to_pwm(struct intel_connector *connector, u32 pwm_freq_hz)
1144 {
1145 	struct intel_display *display = to_intel_display(connector);
1146 	int mul, clock;
1147 
1148 	if ((intel_de_read(display, CBR1_VLV) & CBR_PWM_CLOCK_MUX_SELECT) == 0) {
1149 		if (display->platform.cherryview)
1150 			clock = KHz(19200);
1151 		else
1152 			clock = MHz(25);
1153 		mul = 16;
1154 	} else {
1155 		clock = KHz(DISPLAY_RUNTIME_INFO(display)->rawclk_freq);
1156 		mul = 128;
1157 	}
1158 
1159 	return DIV_ROUND_CLOSEST(clock, pwm_freq_hz * mul);
1160 }
1161 
1162 static u16 get_vbt_pwm_freq(struct intel_connector *connector)
1163 {
1164 	struct intel_display *display = to_intel_display(connector);
1165 	u16 pwm_freq_hz = connector->panel.vbt.backlight.pwm_freq_hz;
1166 
1167 	if (pwm_freq_hz) {
1168 		drm_dbg_kms(display->drm,
1169 			    "VBT defined backlight frequency %u Hz\n",
1170 			    pwm_freq_hz);
1171 	} else {
1172 		pwm_freq_hz = 200;
1173 		drm_dbg_kms(display->drm,
1174 			    "default backlight frequency %u Hz\n",
1175 			    pwm_freq_hz);
1176 	}
1177 
1178 	return pwm_freq_hz;
1179 }
1180 
1181 static u32 get_backlight_max_vbt(struct intel_connector *connector)
1182 {
1183 	struct intel_display *display = to_intel_display(connector);
1184 	struct intel_panel *panel = &connector->panel;
1185 	u16 pwm_freq_hz = get_vbt_pwm_freq(connector);
1186 	u32 pwm;
1187 
1188 	if (!panel->backlight.pwm_funcs->hz_to_pwm) {
1189 		drm_dbg_kms(display->drm,
1190 			    "backlight frequency conversion not supported\n");
1191 		return 0;
1192 	}
1193 
1194 	pwm = panel->backlight.pwm_funcs->hz_to_pwm(connector, pwm_freq_hz);
1195 	if (!pwm) {
1196 		drm_dbg_kms(display->drm,
1197 			    "backlight frequency conversion failed\n");
1198 		return 0;
1199 	}
1200 
1201 	return pwm;
1202 }
1203 
1204 /*
1205  * Note: The setup hooks can't assume pipe is set!
1206  */
1207 static u32 get_backlight_min_vbt(struct intel_connector *connector)
1208 {
1209 	struct intel_display *display = to_intel_display(connector);
1210 	struct intel_panel *panel = &connector->panel;
1211 	int min;
1212 
1213 	drm_WARN_ON(display->drm, panel->backlight.pwm_level_max == 0);
1214 
1215 	/*
1216 	 * XXX: If the vbt value is 255, it makes min equal to max, which leads
1217 	 * to problems. There are such machines out there. Either our
1218 	 * interpretation is wrong or the vbt has bogus data. Or both. Safeguard
1219 	 * against this by letting the minimum be at most (arbitrarily chosen)
1220 	 * 25% of the max.
1221 	 */
1222 	min = clamp_t(int, connector->panel.vbt.backlight.min_brightness, 0, 64);
1223 	if (min != connector->panel.vbt.backlight.min_brightness) {
1224 		drm_dbg_kms(display->drm,
1225 			    "clamping VBT min backlight %d/255 to %d/255\n",
1226 			    connector->panel.vbt.backlight.min_brightness, min);
1227 	}
1228 
1229 	/* vbt value is a coefficient in range [0..255] */
1230 	return scale(min, 0, 255, 0, panel->backlight.pwm_level_max);
1231 }
1232 
1233 static int lpt_setup_backlight(struct intel_connector *connector, enum pipe unused)
1234 {
1235 	struct intel_display *display = to_intel_display(connector);
1236 	struct intel_panel *panel = &connector->panel;
1237 	u32 cpu_ctl2, pch_ctl1, pch_ctl2, val;
1238 	bool alt, cpu_mode;
1239 
1240 	if (HAS_PCH_LPT(display))
1241 		alt = intel_de_read(display, SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY;
1242 	else
1243 		alt = intel_de_read(display, SOUTH_CHICKEN1) & SPT_PWM_GRANULARITY;
1244 	panel->backlight.alternate_pwm_increment = alt;
1245 
1246 	pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
1247 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1248 
1249 	pch_ctl2 = intel_de_read(display, BLC_PWM_PCH_CTL2);
1250 	panel->backlight.pwm_level_max = pch_ctl2 >> 16;
1251 
1252 	cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);
1253 
1254 	if (!panel->backlight.pwm_level_max)
1255 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1256 
1257 	if (!panel->backlight.pwm_level_max)
1258 		return -ENODEV;
1259 
1260 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1261 
1262 	panel->backlight.pwm_enabled = pch_ctl1 & BLM_PCH_PWM_ENABLE;
1263 
1264 	cpu_mode = panel->backlight.pwm_enabled && HAS_PCH_LPT(display) &&
1265 		   !(pch_ctl1 & BLM_PCH_OVERRIDE_ENABLE) &&
1266 		   (cpu_ctl2 & BLM_PWM_ENABLE);
1267 
1268 	if (cpu_mode) {
1269 		val = pch_get_backlight(connector, unused);
1270 
1271 		drm_dbg_kms(display->drm,
1272 			    "CPU backlight register was enabled, switching to PCH override\n");
1273 
1274 		/* Write converted CPU PWM value to PCH override register */
1275 		lpt_set_backlight(connector->base.state, val);
1276 		intel_de_write(display, BLC_PWM_PCH_CTL1,
1277 			       pch_ctl1 | BLM_PCH_OVERRIDE_ENABLE);
1278 
1279 		intel_de_write(display, BLC_PWM_CPU_CTL2,
1280 			       cpu_ctl2 & ~BLM_PWM_ENABLE);
1281 	}
1282 
1283 	drm_dbg_kms(display->drm,
1284 		    "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
1285 		    connector->base.base.id, connector->base.name);
1286 
1287 	return 0;
1288 }
1289 
1290 static int pch_setup_backlight(struct intel_connector *connector, enum pipe unused)
1291 {
1292 	struct intel_display *display = to_intel_display(connector);
1293 	struct intel_panel *panel = &connector->panel;
1294 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
1295 
1296 	pch_ctl1 = intel_de_read(display, BLC_PWM_PCH_CTL1);
1297 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1298 
1299 	pch_ctl2 = intel_de_read(display, BLC_PWM_PCH_CTL2);
1300 	panel->backlight.pwm_level_max = pch_ctl2 >> 16;
1301 
1302 	if (!panel->backlight.pwm_level_max)
1303 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1304 
1305 	if (!panel->backlight.pwm_level_max)
1306 		return -ENODEV;
1307 
1308 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1309 
1310 	cpu_ctl2 = intel_de_read(display, BLC_PWM_CPU_CTL2);
1311 	panel->backlight.pwm_enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
1312 		(pch_ctl1 & BLM_PCH_PWM_ENABLE);
1313 
1314 	drm_dbg_kms(display->drm,
1315 		    "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control\n",
1316 		    connector->base.base.id, connector->base.name);
1317 
1318 	return 0;
1319 }
1320 
1321 static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unused)
1322 {
1323 	struct intel_display *display = to_intel_display(connector);
1324 	struct intel_panel *panel = &connector->panel;
1325 	u32 ctl, val;
1326 
1327 	ctl = intel_de_read(display, BLC_PWM_CTL);
1328 
1329 	if (DISPLAY_VER(display) == 2 || display->platform.i915gm || display->platform.i945gm)
1330 		panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;
1331 
1332 	if (display->platform.pineview)
1333 		panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;
1334 
1335 	panel->backlight.pwm_level_max = ctl >> 17;
1336 
1337 	if (!panel->backlight.pwm_level_max) {
1338 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1339 		panel->backlight.pwm_level_max >>= 1;
1340 	}
1341 
1342 	if (!panel->backlight.pwm_level_max)
1343 		return -ENODEV;
1344 
1345 	if (panel->backlight.combination_mode)
1346 		panel->backlight.pwm_level_max *= 0xff;
1347 
1348 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1349 
1350 	val = i9xx_get_backlight(connector, unused);
1351 	val = intel_backlight_invert_pwm_level(connector, val);
1352 	val = clamp(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);
1353 
1354 	panel->backlight.pwm_enabled = val != 0;
1355 
1356 	drm_dbg_kms(display->drm,
1357 		    "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
1358 		    connector->base.base.id, connector->base.name);
1359 
1360 	return 0;
1361 }
1362 
1363 static int i965_setup_backlight(struct intel_connector *connector, enum pipe unused)
1364 {
1365 	struct intel_display *display = to_intel_display(connector);
1366 	struct intel_panel *panel = &connector->panel;
1367 	u32 ctl, ctl2;
1368 
1369 	ctl2 = intel_de_read(display, BLC_PWM_CTL2);
1370 	panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
1371 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1372 
1373 	ctl = intel_de_read(display, BLC_PWM_CTL);
1374 	panel->backlight.pwm_level_max = ctl >> 16;
1375 
1376 	if (!panel->backlight.pwm_level_max)
1377 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1378 
1379 	if (!panel->backlight.pwm_level_max)
1380 		return -ENODEV;
1381 
1382 	if (panel->backlight.combination_mode)
1383 		panel->backlight.pwm_level_max *= 0xff;
1384 
1385 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1386 
1387 	panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
1388 
1389 	drm_dbg_kms(display->drm,
1390 		    "[CONNECTOR:%d:%s] Using native PWM for backlight control\n",
1391 		    connector->base.base.id, connector->base.name);
1392 
1393 	return 0;
1394 }
1395 
1396 static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe)
1397 {
1398 	struct intel_display *display = to_intel_display(connector);
1399 	struct intel_panel *panel = &connector->panel;
1400 	u32 ctl, ctl2;
1401 
1402 	if (drm_WARN_ON(display->drm, pipe != PIPE_A && pipe != PIPE_B))
1403 		return -ENODEV;
1404 
1405 	ctl2 = intel_de_read(display, VLV_BLC_PWM_CTL2(pipe));
1406 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1407 
1408 	ctl = intel_de_read(display, VLV_BLC_PWM_CTL(pipe));
1409 	panel->backlight.pwm_level_max = ctl >> 16;
1410 
1411 	if (!panel->backlight.pwm_level_max)
1412 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1413 
1414 	if (!panel->backlight.pwm_level_max)
1415 		return -ENODEV;
1416 
1417 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1418 
1419 	panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
1420 
1421 	drm_dbg_kms(display->drm,
1422 		    "[CONNECTOR:%d:%s] Using native PWM for backlight control (on pipe %c)\n",
1423 		    connector->base.base.id, connector->base.name, pipe_name(pipe));
1424 
1425 	return 0;
1426 }
1427 
1428 static int
1429 bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
1430 {
1431 	struct intel_display *display = to_intel_display(connector);
1432 	struct intel_panel *panel = &connector->panel;
1433 	u32 pwm_ctl, val;
1434 
1435 	panel->backlight.controller = connector->panel.vbt.backlight.controller;
1436 
1437 	pwm_ctl = intel_de_read(display,
1438 				BXT_BLC_PWM_CTL(panel->backlight.controller));
1439 
1440 	/* Controller 1 uses the utility pin. */
1441 	if (panel->backlight.controller == 1) {
1442 		val = intel_de_read(display, UTIL_PIN_CTL);
1443 		panel->backlight.util_pin_active_low =
1444 					val & UTIL_PIN_POLARITY;
1445 	}
1446 
1447 	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
1448 	panel->backlight.pwm_level_max =
1449 		intel_de_read(display, BXT_BLC_PWM_FREQ(panel->backlight.controller));
1450 
1451 	if (!panel->backlight.pwm_level_max)
1452 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1453 
1454 	if (!panel->backlight.pwm_level_max)
1455 		return -ENODEV;
1456 
1457 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1458 
1459 	panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
1460 
1461 	drm_dbg_kms(display->drm,
1462 		    "[CONNECTOR:%d:%s] Using native PWM for backlight control (controller=%d)\n",
1463 		    connector->base.base.id, connector->base.name,
1464 		    panel->backlight.controller);
1465 
1466 	return 0;
1467 }
1468 
1469 static int cnp_num_backlight_controllers(struct intel_display *display)
1470 {
1471 	if (INTEL_PCH_TYPE(display) >= PCH_MTL)
1472 		return 2;
1473 
1474 	if (INTEL_PCH_TYPE(display) >= PCH_DG1)
1475 		return 1;
1476 
1477 	if (INTEL_PCH_TYPE(display) >= PCH_ICP)
1478 		return 2;
1479 
1480 	return 1;
1481 }
1482 
1483 static bool cnp_backlight_controller_is_valid(struct intel_display *display, int controller)
1484 {
1485 	if (controller < 0 || controller >= cnp_num_backlight_controllers(display))
1486 		return false;
1487 
1488 	if (controller == 1 &&
1489 	    INTEL_PCH_TYPE(display) >= PCH_ICP &&
1490 	    INTEL_PCH_TYPE(display) <= PCH_ADP)
1491 		return intel_de_read(display, SOUTH_CHICKEN1) & ICP_SECOND_PPS_IO_SELECT;
1492 
1493 	return true;
1494 }
1495 
1496 static int
1497 cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
1498 {
1499 	struct intel_display *display = to_intel_display(connector);
1500 	struct intel_panel *panel = &connector->panel;
1501 	u32 pwm_ctl;
1502 
1503 	/*
1504 	 * CNP has the BXT implementation of backlight, but with only one
1505 	 * controller. ICP+ can have two controllers, depending on pin muxing.
1506 	 */
1507 	panel->backlight.controller = connector->panel.vbt.backlight.controller;
1508 	if (!cnp_backlight_controller_is_valid(display, panel->backlight.controller)) {
1509 		drm_dbg_kms(display->drm,
1510 			    "[CONNECTOR:%d:%s] Invalid backlight controller %d, assuming 0\n",
1511 			    connector->base.base.id, connector->base.name,
1512 			    panel->backlight.controller);
1513 		panel->backlight.controller = 0;
1514 	}
1515 
1516 	pwm_ctl = intel_de_read(display,
1517 				BXT_BLC_PWM_CTL(panel->backlight.controller));
1518 
1519 	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
1520 	panel->backlight.pwm_level_max =
1521 		intel_de_read(display, BXT_BLC_PWM_FREQ(panel->backlight.controller));
1522 
1523 	if (!panel->backlight.pwm_level_max)
1524 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1525 
1526 	if (!panel->backlight.pwm_level_max)
1527 		return -ENODEV;
1528 
1529 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1530 
1531 	panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
1532 
1533 	drm_dbg_kms(display->drm,
1534 		    "[CONNECTOR:%d:%s] Using native PCH PWM for backlight control (controller=%d)\n",
1535 		    connector->base.base.id, connector->base.name,
1536 		    panel->backlight.controller);
1537 
1538 	return 0;
1539 }
1540 
1541 static int ext_pwm_setup_backlight(struct intel_connector *connector,
1542 				   enum pipe pipe)
1543 {
1544 	struct intel_display *display = to_intel_display(connector);
1545 	struct intel_panel *panel = &connector->panel;
1546 	const char *desc;
1547 	u32 level;
1548 
1549 	/* Get the right PWM chip for DSI backlight according to VBT */
1550 	if (connector->panel.vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) {
1551 		panel->backlight.pwm = pwm_get(display->drm->dev,
1552 					       "pwm_pmic_backlight");
1553 		desc = "PMIC";
1554 	} else {
1555 		panel->backlight.pwm = pwm_get(display->drm->dev,
1556 					       "pwm_soc_backlight");
1557 		desc = "SoC";
1558 	}
1559 
1560 	if (IS_ERR(panel->backlight.pwm)) {
1561 		drm_err(display->drm,
1562 			"[CONNECTOR:%d:%s] Failed to get the %s PWM chip\n",
1563 			connector->base.base.id, connector->base.name, desc);
1564 		panel->backlight.pwm = NULL;
1565 		return -ENODEV;
1566 	}
1567 
1568 	panel->backlight.pwm_level_max = 100; /* 100% */
1569 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1570 
1571 	if (pwm_is_enabled(panel->backlight.pwm)) {
1572 		/* PWM is already enabled, use existing settings */
1573 		pwm_get_state(panel->backlight.pwm, &panel->backlight.pwm_state);
1574 
1575 		level = pwm_get_relative_duty_cycle(&panel->backlight.pwm_state,
1576 						    100);
1577 		level = intel_backlight_invert_pwm_level(connector, level);
1578 		panel->backlight.pwm_enabled = true;
1579 
1580 		drm_dbg_kms(display->drm,
1581 			    "[CONNECTOR:%d:%s] PWM already enabled at freq %ld, VBT freq %d, level %d\n",
1582 			    connector->base.base.id, connector->base.name,
1583 			    NSEC_PER_SEC / (unsigned long)panel->backlight.pwm_state.period,
1584 			    get_vbt_pwm_freq(connector), level);
1585 	} else {
1586 		/* Set period from VBT frequency, leave other settings at 0. */
1587 		panel->backlight.pwm_state.period =
1588 			NSEC_PER_SEC / get_vbt_pwm_freq(connector);
1589 	}
1590 
1591 	drm_dbg_kms(display->drm,
1592 		    "[CONNECTOR:%d:%s] Using %s PWM for backlight control\n",
1593 		    connector->base.base.id, connector->base.name, desc);
1594 
1595 	return 0;
1596 }
1597 
1598 static void intel_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
1599 {
1600 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1601 	struct intel_panel *panel = &connector->panel;
1602 
1603 	panel->backlight.pwm_funcs->set(conn_state,
1604 					intel_backlight_invert_pwm_level(connector, level));
1605 }
1606 
1607 static u32 intel_pwm_get_backlight(struct intel_connector *connector, enum pipe pipe)
1608 {
1609 	struct intel_panel *panel = &connector->panel;
1610 
1611 	return intel_backlight_invert_pwm_level(connector,
1612 					    panel->backlight.pwm_funcs->get(connector, pipe));
1613 }
1614 
1615 static void intel_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
1616 				       const struct drm_connector_state *conn_state, u32 level)
1617 {
1618 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1619 	struct intel_panel *panel = &connector->panel;
1620 
1621 	panel->backlight.pwm_funcs->enable(crtc_state, conn_state,
1622 					   intel_backlight_invert_pwm_level(connector, level));
1623 }
1624 
1625 static void intel_pwm_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
1626 {
1627 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1628 	struct intel_panel *panel = &connector->panel;
1629 
1630 	panel->backlight.pwm_funcs->disable(conn_state,
1631 					    intel_backlight_invert_pwm_level(connector, level));
1632 }
1633 
1634 static int intel_pwm_setup_backlight(struct intel_connector *connector, enum pipe pipe)
1635 {
1636 	struct intel_panel *panel = &connector->panel;
1637 	int ret;
1638 
1639 	ret = panel->backlight.pwm_funcs->setup(connector, pipe);
1640 	if (ret < 0)
1641 		return ret;
1642 
1643 	panel->backlight.min = panel->backlight.pwm_level_min;
1644 	panel->backlight.max = panel->backlight.pwm_level_max;
1645 	panel->backlight.level = intel_pwm_get_backlight(connector, pipe);
1646 	panel->backlight.enabled = panel->backlight.pwm_enabled;
1647 
1648 	return 0;
1649 }
1650 
1651 void intel_backlight_update(struct intel_atomic_state *state,
1652 			    struct intel_encoder *encoder,
1653 			    const struct intel_crtc_state *crtc_state,
1654 			    const struct drm_connector_state *conn_state)
1655 {
1656 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1657 	struct intel_display *display = to_intel_display(connector);
1658 	struct intel_panel *panel = &connector->panel;
1659 
1660 	if (!panel->backlight.present)
1661 		return;
1662 
1663 	mutex_lock(&display->backlight.lock);
1664 	if (!panel->backlight.enabled)
1665 		__intel_backlight_enable(crtc_state, conn_state);
1666 
1667 	mutex_unlock(&display->backlight.lock);
1668 }
1669 
1670 int intel_backlight_setup(struct intel_connector *connector, enum pipe pipe)
1671 {
1672 	struct intel_display *display = to_intel_display(connector);
1673 	struct intel_panel *panel = &connector->panel;
1674 	int ret;
1675 
1676 	if (!connector->panel.vbt.backlight.present) {
1677 		if (intel_has_quirk(display, QUIRK_BACKLIGHT_PRESENT)) {
1678 			drm_dbg_kms(display->drm,
1679 				    "[CONNECTOR:%d:%s] no backlight present per VBT, but present per quirk\n",
1680 				    connector->base.base.id, connector->base.name);
1681 		} else {
1682 			drm_dbg_kms(display->drm,
1683 				    "[CONNECTOR:%d:%s] no backlight present per VBT\n",
1684 				    connector->base.base.id, connector->base.name);
1685 			return 0;
1686 		}
1687 	}
1688 
1689 	/* ensure intel_panel has been initialized first */
1690 	if (drm_WARN_ON(display->drm, !panel->backlight.funcs))
1691 		return -ENODEV;
1692 
1693 	/* set level and max in panel struct */
1694 	mutex_lock(&display->backlight.lock);
1695 	ret = panel->backlight.funcs->setup(connector, pipe);
1696 	mutex_unlock(&display->backlight.lock);
1697 
1698 	if (ret) {
1699 		drm_dbg_kms(display->drm,
1700 			    "[CONNECTOR:%d:%s] failed to setup backlight\n",
1701 			    connector->base.base.id, connector->base.name);
1702 		return ret;
1703 	}
1704 
1705 	panel->backlight.present = true;
1706 
1707 	drm_dbg_kms(display->drm,
1708 		    "[CONNECTOR:%d:%s] backlight initialized, %s, brightness %u/%u\n",
1709 		    connector->base.base.id, connector->base.name,
1710 		    str_enabled_disabled(panel->backlight.enabled),
1711 		    panel->backlight.level, panel->backlight.max);
1712 
1713 	return 0;
1714 }
1715 
1716 void intel_backlight_destroy(struct intel_panel *panel)
1717 {
1718 	/* dispose of the pwm */
1719 	if (panel->backlight.pwm)
1720 		pwm_put(panel->backlight.pwm);
1721 
1722 	panel->backlight.present = false;
1723 }
1724 
1725 static const struct intel_panel_bl_funcs bxt_pwm_funcs = {
1726 	.setup = bxt_setup_backlight,
1727 	.enable = bxt_enable_backlight,
1728 	.disable = bxt_disable_backlight,
1729 	.set = bxt_set_backlight,
1730 	.get = bxt_get_backlight,
1731 	.hz_to_pwm = bxt_hz_to_pwm,
1732 };
1733 
1734 static const struct intel_panel_bl_funcs cnp_pwm_funcs = {
1735 	.setup = cnp_setup_backlight,
1736 	.enable = cnp_enable_backlight,
1737 	.disable = cnp_disable_backlight,
1738 	.set = bxt_set_backlight,
1739 	.get = bxt_get_backlight,
1740 	.hz_to_pwm = cnp_hz_to_pwm,
1741 };
1742 
1743 static const struct intel_panel_bl_funcs lpt_pwm_funcs = {
1744 	.setup = lpt_setup_backlight,
1745 	.enable = lpt_enable_backlight,
1746 	.disable = lpt_disable_backlight,
1747 	.set = lpt_set_backlight,
1748 	.get = lpt_get_backlight,
1749 	.hz_to_pwm = lpt_hz_to_pwm,
1750 };
1751 
1752 static const struct intel_panel_bl_funcs spt_pwm_funcs = {
1753 	.setup = lpt_setup_backlight,
1754 	.enable = lpt_enable_backlight,
1755 	.disable = lpt_disable_backlight,
1756 	.set = lpt_set_backlight,
1757 	.get = lpt_get_backlight,
1758 	.hz_to_pwm = spt_hz_to_pwm,
1759 };
1760 
1761 static const struct intel_panel_bl_funcs pch_pwm_funcs = {
1762 	.setup = pch_setup_backlight,
1763 	.enable = pch_enable_backlight,
1764 	.disable = pch_disable_backlight,
1765 	.set = pch_set_backlight,
1766 	.get = pch_get_backlight,
1767 	.hz_to_pwm = pch_hz_to_pwm,
1768 };
1769 
1770 static const struct intel_panel_bl_funcs ext_pwm_funcs = {
1771 	.setup = ext_pwm_setup_backlight,
1772 	.enable = ext_pwm_enable_backlight,
1773 	.disable = ext_pwm_disable_backlight,
1774 	.set = ext_pwm_set_backlight,
1775 	.get = ext_pwm_get_backlight,
1776 };
1777 
1778 static const struct intel_panel_bl_funcs vlv_pwm_funcs = {
1779 	.setup = vlv_setup_backlight,
1780 	.enable = vlv_enable_backlight,
1781 	.disable = vlv_disable_backlight,
1782 	.set = vlv_set_backlight,
1783 	.get = vlv_get_backlight,
1784 	.hz_to_pwm = vlv_hz_to_pwm,
1785 };
1786 
1787 static const struct intel_panel_bl_funcs i965_pwm_funcs = {
1788 	.setup = i965_setup_backlight,
1789 	.enable = i965_enable_backlight,
1790 	.disable = i965_disable_backlight,
1791 	.set = i9xx_set_backlight,
1792 	.get = i9xx_get_backlight,
1793 	.hz_to_pwm = i965_hz_to_pwm,
1794 };
1795 
1796 static const struct intel_panel_bl_funcs i9xx_pwm_funcs = {
1797 	.setup = i9xx_setup_backlight,
1798 	.enable = i9xx_enable_backlight,
1799 	.disable = i9xx_disable_backlight,
1800 	.set = i9xx_set_backlight,
1801 	.get = i9xx_get_backlight,
1802 	.hz_to_pwm = i9xx_hz_to_pwm,
1803 };
1804 
1805 static const struct intel_panel_bl_funcs pwm_bl_funcs = {
1806 	.setup = intel_pwm_setup_backlight,
1807 	.enable = intel_pwm_enable_backlight,
1808 	.disable = intel_pwm_disable_backlight,
1809 	.set = intel_pwm_set_backlight,
1810 	.get = intel_pwm_get_backlight,
1811 };
1812 
1813 /* Set up chip specific backlight functions */
1814 void intel_backlight_init_funcs(struct intel_panel *panel)
1815 {
1816 	struct intel_connector *connector =
1817 		container_of(panel, struct intel_connector, panel);
1818 	struct intel_display *display = to_intel_display(connector);
1819 
1820 	if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI &&
1821 	    intel_dsi_dcs_init_backlight_funcs(connector) == 0)
1822 		return;
1823 
1824 	if (display->platform.geminilake || display->platform.broxton) {
1825 		panel->backlight.pwm_funcs = &bxt_pwm_funcs;
1826 	} else if (INTEL_PCH_TYPE(display) >= PCH_CNP) {
1827 		panel->backlight.pwm_funcs = &cnp_pwm_funcs;
1828 	} else if (INTEL_PCH_TYPE(display) >= PCH_LPT_H) {
1829 		if (HAS_PCH_LPT(display))
1830 			panel->backlight.pwm_funcs = &lpt_pwm_funcs;
1831 		else
1832 			panel->backlight.pwm_funcs = &spt_pwm_funcs;
1833 	} else if (HAS_PCH_SPLIT(display)) {
1834 		panel->backlight.pwm_funcs = &pch_pwm_funcs;
1835 	} else if (display->platform.valleyview || display->platform.cherryview) {
1836 		if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI) {
1837 			panel->backlight.pwm_funcs = &ext_pwm_funcs;
1838 		} else {
1839 			panel->backlight.pwm_funcs = &vlv_pwm_funcs;
1840 		}
1841 	} else if (DISPLAY_VER(display) == 4) {
1842 		panel->backlight.pwm_funcs = &i965_pwm_funcs;
1843 	} else {
1844 		panel->backlight.pwm_funcs = &i9xx_pwm_funcs;
1845 	}
1846 
1847 	if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
1848 		if (intel_dp_aux_init_backlight_funcs(connector) == 0)
1849 			return;
1850 
1851 		if (!intel_has_quirk(display, QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
1852 			connector->panel.backlight.power = intel_pps_backlight_power;
1853 	}
1854 
1855 	/* We're using a standard PWM backlight interface */
1856 	panel->backlight.funcs = &pwm_bl_funcs;
1857 }
1858