xref: /linux/drivers/gpu/drm/i915/display/intel_backlight.c (revision 6a02124c87f0b61dcaaeb65e7fd406d8afb40fd4)
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 
11 #include "intel_backlight.h"
12 #include "intel_connector.h"
13 #include "intel_de.h"
14 #include "intel_display_types.h"
15 #include "intel_dp_aux_backlight.h"
16 #include "intel_dsi_dcs_backlight.h"
17 #include "intel_panel.h"
18 #include "intel_pci_config.h"
19 #include "intel_pps.h"
20 
21 /**
22  * scale - scale values from one range to another
23  * @source_val: value in range [@source_min..@source_max]
24  * @source_min: minimum legal value for @source_val
25  * @source_max: maximum legal value for @source_val
26  * @target_min: corresponding target value for @source_min
27  * @target_max: corresponding target value for @source_max
28  *
29  * Return @source_val in range [@source_min..@source_max] scaled to range
30  * [@target_min..@target_max].
31  */
32 static u32 scale(u32 source_val,
33 		 u32 source_min, u32 source_max,
34 		 u32 target_min, u32 target_max)
35 {
36 	u64 target_val;
37 
38 	WARN_ON(source_min > source_max);
39 	WARN_ON(target_min > target_max);
40 
41 	/* defensive */
42 	source_val = clamp(source_val, source_min, source_max);
43 
44 	/* avoid overflows */
45 	target_val = mul_u32_u32(source_val - source_min,
46 				 target_max - target_min);
47 	target_val = DIV_ROUND_CLOSEST_ULL(target_val, source_max - source_min);
48 	target_val += target_min;
49 
50 	return target_val;
51 }
52 
53 /*
54  * Scale user_level in range [0..user_max] to [0..hw_max], clamping the result
55  * to [hw_min..hw_max].
56  */
57 static u32 clamp_user_to_hw(struct intel_connector *connector,
58 			    u32 user_level, u32 user_max)
59 {
60 	struct intel_panel *panel = &connector->panel;
61 	u32 hw_level;
62 
63 	hw_level = scale(user_level, 0, user_max, 0, panel->backlight.max);
64 	hw_level = clamp(hw_level, panel->backlight.min, panel->backlight.max);
65 
66 	return hw_level;
67 }
68 
69 /* Scale hw_level in range [hw_min..hw_max] to [0..user_max]. */
70 static u32 scale_hw_to_user(struct intel_connector *connector,
71 			    u32 hw_level, u32 user_max)
72 {
73 	struct intel_panel *panel = &connector->panel;
74 
75 	return scale(hw_level, panel->backlight.min, panel->backlight.max,
76 		     0, user_max);
77 }
78 
79 u32 intel_backlight_invert_pwm_level(struct intel_connector *connector, u32 val)
80 {
81 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
82 	struct intel_panel *panel = &connector->panel;
83 
84 	drm_WARN_ON(&dev_priv->drm, panel->backlight.pwm_level_max == 0);
85 
86 	if (dev_priv->params.invert_brightness < 0)
87 		return val;
88 
89 	if (dev_priv->params.invert_brightness > 0 ||
90 	    dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS) {
91 		return panel->backlight.pwm_level_max - val + panel->backlight.pwm_level_min;
92 	}
93 
94 	return val;
95 }
96 
97 void intel_backlight_set_pwm_level(const struct drm_connector_state *conn_state, u32 val)
98 {
99 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
100 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
101 	struct intel_panel *panel = &connector->panel;
102 
103 	drm_dbg_kms(&i915->drm, "set backlight PWM = %d\n", val);
104 	panel->backlight.pwm_funcs->set(conn_state, val);
105 }
106 
107 u32 intel_backlight_level_to_pwm(struct intel_connector *connector, u32 val)
108 {
109 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
110 	struct intel_panel *panel = &connector->panel;
111 
112 	drm_WARN_ON_ONCE(&dev_priv->drm,
113 			 panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);
114 
115 	val = scale(val, panel->backlight.min, panel->backlight.max,
116 		    panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);
117 
118 	return intel_backlight_invert_pwm_level(connector, val);
119 }
120 
121 u32 intel_backlight_level_from_pwm(struct intel_connector *connector, u32 val)
122 {
123 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
124 	struct intel_panel *panel = &connector->panel;
125 
126 	drm_WARN_ON_ONCE(&dev_priv->drm,
127 			 panel->backlight.max == 0 || panel->backlight.pwm_level_max == 0);
128 
129 	if (dev_priv->params.invert_brightness > 0 ||
130 	    (dev_priv->params.invert_brightness == 0 && dev_priv->quirks & QUIRK_INVERT_BRIGHTNESS))
131 		val = panel->backlight.pwm_level_max - (val - panel->backlight.pwm_level_min);
132 
133 	return scale(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max,
134 		     panel->backlight.min, panel->backlight.max);
135 }
136 
137 static u32 lpt_get_backlight(struct intel_connector *connector, enum pipe unused)
138 {
139 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
140 
141 	return intel_de_read(dev_priv, BLC_PWM_PCH_CTL2) & BACKLIGHT_DUTY_CYCLE_MASK;
142 }
143 
144 static u32 pch_get_backlight(struct intel_connector *connector, enum pipe unused)
145 {
146 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
147 
148 	return intel_de_read(dev_priv, BLC_PWM_CPU_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
149 }
150 
151 static u32 i9xx_get_backlight(struct intel_connector *connector, enum pipe unused)
152 {
153 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
154 	struct intel_panel *panel = &connector->panel;
155 	u32 val;
156 
157 	val = intel_de_read(dev_priv, BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK;
158 	if (DISPLAY_VER(dev_priv) < 4)
159 		val >>= 1;
160 
161 	if (panel->backlight.combination_mode) {
162 		u8 lbpc;
163 
164 		pci_read_config_byte(to_pci_dev(dev_priv->drm.dev), LBPC, &lbpc);
165 		val *= lbpc;
166 	}
167 
168 	return val;
169 }
170 
171 static u32 vlv_get_backlight(struct intel_connector *connector, enum pipe pipe)
172 {
173 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
174 
175 	if (drm_WARN_ON(&dev_priv->drm, pipe != PIPE_A && pipe != PIPE_B))
176 		return 0;
177 
178 	return intel_de_read(dev_priv, VLV_BLC_PWM_CTL(pipe)) & BACKLIGHT_DUTY_CYCLE_MASK;
179 }
180 
181 static u32 bxt_get_backlight(struct intel_connector *connector, enum pipe unused)
182 {
183 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
184 	struct intel_panel *panel = &connector->panel;
185 
186 	return intel_de_read(dev_priv,
187 			     BXT_BLC_PWM_DUTY(panel->backlight.controller));
188 }
189 
190 static u32 ext_pwm_get_backlight(struct intel_connector *connector, enum pipe unused)
191 {
192 	struct intel_panel *panel = &connector->panel;
193 	struct pwm_state state;
194 
195 	pwm_get_state(panel->backlight.pwm, &state);
196 	return pwm_get_relative_duty_cycle(&state, 100);
197 }
198 
199 static void lpt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
200 {
201 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
202 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
203 
204 	u32 val = intel_de_read(dev_priv, BLC_PWM_PCH_CTL2) & ~BACKLIGHT_DUTY_CYCLE_MASK;
205 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL2, val | level);
206 }
207 
208 static void pch_set_backlight(const struct drm_connector_state *conn_state, u32 level)
209 {
210 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
211 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
212 	u32 tmp;
213 
214 	tmp = intel_de_read(dev_priv, BLC_PWM_CPU_CTL) & ~BACKLIGHT_DUTY_CYCLE_MASK;
215 	intel_de_write(dev_priv, BLC_PWM_CPU_CTL, tmp | level);
216 }
217 
218 static void i9xx_set_backlight(const struct drm_connector_state *conn_state, u32 level)
219 {
220 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
221 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
222 	struct intel_panel *panel = &connector->panel;
223 	u32 tmp, mask;
224 
225 	drm_WARN_ON(&dev_priv->drm, panel->backlight.pwm_level_max == 0);
226 
227 	if (panel->backlight.combination_mode) {
228 		u8 lbpc;
229 
230 		lbpc = level * 0xfe / panel->backlight.pwm_level_max + 1;
231 		level /= lbpc;
232 		pci_write_config_byte(to_pci_dev(dev_priv->drm.dev), LBPC, lbpc);
233 	}
234 
235 	if (DISPLAY_VER(dev_priv) == 4) {
236 		mask = BACKLIGHT_DUTY_CYCLE_MASK;
237 	} else {
238 		level <<= 1;
239 		mask = BACKLIGHT_DUTY_CYCLE_MASK_PNV;
240 	}
241 
242 	tmp = intel_de_read(dev_priv, BLC_PWM_CTL) & ~mask;
243 	intel_de_write(dev_priv, BLC_PWM_CTL, tmp | level);
244 }
245 
246 static void vlv_set_backlight(const struct drm_connector_state *conn_state, u32 level)
247 {
248 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
249 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
250 	enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
251 	u32 tmp;
252 
253 	tmp = intel_de_read(dev_priv, VLV_BLC_PWM_CTL(pipe)) & ~BACKLIGHT_DUTY_CYCLE_MASK;
254 	intel_de_write(dev_priv, VLV_BLC_PWM_CTL(pipe), tmp | level);
255 }
256 
257 static void bxt_set_backlight(const struct drm_connector_state *conn_state, u32 level)
258 {
259 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
260 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
261 	struct intel_panel *panel = &connector->panel;
262 
263 	intel_de_write(dev_priv,
264 		       BXT_BLC_PWM_DUTY(panel->backlight.controller), level);
265 }
266 
267 static void ext_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
268 {
269 	struct intel_panel *panel = &to_intel_connector(conn_state->connector)->panel;
270 
271 	pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
272 	pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state);
273 }
274 
275 static void
276 intel_panel_actually_set_backlight(const struct drm_connector_state *conn_state, u32 level)
277 {
278 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
279 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
280 	struct intel_panel *panel = &connector->panel;
281 
282 	drm_dbg_kms(&i915->drm, "set backlight level = %d\n", level);
283 
284 	panel->backlight.funcs->set(conn_state, level);
285 }
286 
287 /* set backlight brightness to level in range [0..max], assuming hw min is
288  * respected.
289  */
290 void intel_backlight_set_acpi(const struct drm_connector_state *conn_state,
291 			      u32 user_level, u32 user_max)
292 {
293 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
294 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
295 	struct intel_panel *panel = &connector->panel;
296 	u32 hw_level;
297 
298 	/*
299 	 * Lack of crtc may occur during driver init because
300 	 * connection_mutex isn't held across the entire backlight
301 	 * setup + modeset readout, and the BIOS can issue the
302 	 * requests at any time.
303 	 */
304 	if (!panel->backlight.present || !conn_state->crtc)
305 		return;
306 
307 	mutex_lock(&dev_priv->backlight_lock);
308 
309 	drm_WARN_ON(&dev_priv->drm, panel->backlight.max == 0);
310 
311 	hw_level = clamp_user_to_hw(connector, user_level, user_max);
312 	panel->backlight.level = hw_level;
313 
314 	if (panel->backlight.device)
315 		panel->backlight.device->props.brightness =
316 			scale_hw_to_user(connector,
317 					 panel->backlight.level,
318 					 panel->backlight.device->props.max_brightness);
319 
320 	if (panel->backlight.enabled)
321 		intel_panel_actually_set_backlight(conn_state, hw_level);
322 
323 	mutex_unlock(&dev_priv->backlight_lock);
324 }
325 
326 static void lpt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
327 {
328 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
329 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
330 	u32 tmp;
331 
332 	intel_backlight_set_pwm_level(old_conn_state, level);
333 
334 	/*
335 	 * Although we don't support or enable CPU PWM with LPT/SPT based
336 	 * systems, it may have been enabled prior to loading the
337 	 * driver. Disable to avoid warnings on LCPLL disable.
338 	 *
339 	 * This needs rework if we need to add support for CPU PWM on PCH split
340 	 * platforms.
341 	 */
342 	tmp = intel_de_read(dev_priv, BLC_PWM_CPU_CTL2);
343 	if (tmp & BLM_PWM_ENABLE) {
344 		drm_dbg_kms(&dev_priv->drm,
345 			    "cpu backlight was enabled, disabling\n");
346 		intel_de_write(dev_priv, BLC_PWM_CPU_CTL2,
347 			       tmp & ~BLM_PWM_ENABLE);
348 	}
349 
350 	tmp = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
351 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
352 }
353 
354 static void pch_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
355 {
356 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
357 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
358 	u32 tmp;
359 
360 	intel_backlight_set_pwm_level(old_conn_state, val);
361 
362 	tmp = intel_de_read(dev_priv, BLC_PWM_CPU_CTL2);
363 	intel_de_write(dev_priv, BLC_PWM_CPU_CTL2, tmp & ~BLM_PWM_ENABLE);
364 
365 	tmp = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
366 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, tmp & ~BLM_PCH_PWM_ENABLE);
367 }
368 
369 static void i9xx_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
370 {
371 	intel_backlight_set_pwm_level(old_conn_state, val);
372 }
373 
374 static void i965_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
375 {
376 	struct drm_i915_private *dev_priv = to_i915(old_conn_state->connector->dev);
377 	u32 tmp;
378 
379 	intel_backlight_set_pwm_level(old_conn_state, val);
380 
381 	tmp = intel_de_read(dev_priv, BLC_PWM_CTL2);
382 	intel_de_write(dev_priv, BLC_PWM_CTL2, tmp & ~BLM_PWM_ENABLE);
383 }
384 
385 static void vlv_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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
389 	enum pipe pipe = to_intel_crtc(old_conn_state->crtc)->pipe;
390 	u32 tmp;
391 
392 	intel_backlight_set_pwm_level(old_conn_state, val);
393 
394 	tmp = intel_de_read(dev_priv, VLV_BLC_PWM_CTL2(pipe));
395 	intel_de_write(dev_priv, VLV_BLC_PWM_CTL2(pipe),
396 		       tmp & ~BLM_PWM_ENABLE);
397 }
398 
399 static void bxt_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
400 {
401 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
402 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
403 	struct intel_panel *panel = &connector->panel;
404 	u32 tmp;
405 
406 	intel_backlight_set_pwm_level(old_conn_state, val);
407 
408 	tmp = intel_de_read(dev_priv,
409 			    BXT_BLC_PWM_CTL(panel->backlight.controller));
410 	intel_de_write(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
411 		       tmp & ~BXT_BLC_PWM_ENABLE);
412 
413 	if (panel->backlight.controller == 1) {
414 		val = intel_de_read(dev_priv, UTIL_PIN_CTL);
415 		val &= ~UTIL_PIN_ENABLE;
416 		intel_de_write(dev_priv, UTIL_PIN_CTL, val);
417 	}
418 }
419 
420 static void cnp_disable_backlight(const struct drm_connector_state *old_conn_state, u32 val)
421 {
422 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
423 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
424 	struct intel_panel *panel = &connector->panel;
425 	u32 tmp;
426 
427 	intel_backlight_set_pwm_level(old_conn_state, val);
428 
429 	tmp = intel_de_read(dev_priv,
430 			    BXT_BLC_PWM_CTL(panel->backlight.controller));
431 	intel_de_write(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
432 		       tmp & ~BXT_BLC_PWM_ENABLE);
433 }
434 
435 static void ext_pwm_disable_backlight(const struct drm_connector_state *old_conn_state, u32 level)
436 {
437 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
438 	struct intel_panel *panel = &connector->panel;
439 
440 	intel_backlight_set_pwm_level(old_conn_state, level);
441 
442 	panel->backlight.pwm_state.enabled = false;
443 	pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state);
444 }
445 
446 void intel_backlight_disable(const struct drm_connector_state *old_conn_state)
447 {
448 	struct intel_connector *connector = to_intel_connector(old_conn_state->connector);
449 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
450 	struct intel_panel *panel = &connector->panel;
451 
452 	if (!panel->backlight.present)
453 		return;
454 
455 	/*
456 	 * Do not disable backlight on the vga_switcheroo path. When switching
457 	 * away from i915, the other client may depend on i915 to handle the
458 	 * backlight. This will leave the backlight on unnecessarily when
459 	 * another client is not activated.
460 	 */
461 	if (dev_priv->drm.switch_power_state == DRM_SWITCH_POWER_CHANGING) {
462 		drm_dbg_kms(&dev_priv->drm,
463 			    "Skipping backlight disable on vga switch\n");
464 		return;
465 	}
466 
467 	mutex_lock(&dev_priv->backlight_lock);
468 
469 	if (panel->backlight.device)
470 		panel->backlight.device->props.power = FB_BLANK_POWERDOWN;
471 	panel->backlight.enabled = false;
472 	panel->backlight.funcs->disable(old_conn_state, 0);
473 
474 	mutex_unlock(&dev_priv->backlight_lock);
475 }
476 
477 static void lpt_enable_backlight(const struct intel_crtc_state *crtc_state,
478 				 const struct drm_connector_state *conn_state, u32 level)
479 {
480 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
481 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
482 	struct intel_panel *panel = &connector->panel;
483 	u32 pch_ctl1, pch_ctl2, schicken;
484 
485 	pch_ctl1 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
486 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
487 		drm_dbg_kms(&dev_priv->drm, "pch backlight already enabled\n");
488 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
489 		intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, pch_ctl1);
490 	}
491 
492 	if (HAS_PCH_LPT(dev_priv)) {
493 		schicken = intel_de_read(dev_priv, SOUTH_CHICKEN2);
494 		if (panel->backlight.alternate_pwm_increment)
495 			schicken |= LPT_PWM_GRANULARITY;
496 		else
497 			schicken &= ~LPT_PWM_GRANULARITY;
498 		intel_de_write(dev_priv, SOUTH_CHICKEN2, schicken);
499 	} else {
500 		schicken = intel_de_read(dev_priv, SOUTH_CHICKEN1);
501 		if (panel->backlight.alternate_pwm_increment)
502 			schicken |= SPT_PWM_GRANULARITY;
503 		else
504 			schicken &= ~SPT_PWM_GRANULARITY;
505 		intel_de_write(dev_priv, SOUTH_CHICKEN1, schicken);
506 	}
507 
508 	pch_ctl2 = panel->backlight.pwm_level_max << 16;
509 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL2, pch_ctl2);
510 
511 	pch_ctl1 = 0;
512 	if (panel->backlight.active_low_pwm)
513 		pch_ctl1 |= BLM_PCH_POLARITY;
514 
515 	/* After LPT, override is the default. */
516 	if (HAS_PCH_LPT(dev_priv))
517 		pch_ctl1 |= BLM_PCH_OVERRIDE_ENABLE;
518 
519 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, pch_ctl1);
520 	intel_de_posting_read(dev_priv, BLC_PWM_PCH_CTL1);
521 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1,
522 		       pch_ctl1 | BLM_PCH_PWM_ENABLE);
523 
524 	/* This won't stick until the above enable. */
525 	intel_backlight_set_pwm_level(conn_state, level);
526 }
527 
528 static void pch_enable_backlight(const struct intel_crtc_state *crtc_state,
529 				 const struct drm_connector_state *conn_state, u32 level)
530 {
531 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
532 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
533 	struct intel_panel *panel = &connector->panel;
534 	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
535 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
536 
537 	cpu_ctl2 = intel_de_read(dev_priv, BLC_PWM_CPU_CTL2);
538 	if (cpu_ctl2 & BLM_PWM_ENABLE) {
539 		drm_dbg_kms(&dev_priv->drm, "cpu backlight already enabled\n");
540 		cpu_ctl2 &= ~BLM_PWM_ENABLE;
541 		intel_de_write(dev_priv, BLC_PWM_CPU_CTL2, cpu_ctl2);
542 	}
543 
544 	pch_ctl1 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
545 	if (pch_ctl1 & BLM_PCH_PWM_ENABLE) {
546 		drm_dbg_kms(&dev_priv->drm, "pch backlight already enabled\n");
547 		pch_ctl1 &= ~BLM_PCH_PWM_ENABLE;
548 		intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, pch_ctl1);
549 	}
550 
551 	if (cpu_transcoder == TRANSCODER_EDP)
552 		cpu_ctl2 = BLM_TRANSCODER_EDP;
553 	else
554 		cpu_ctl2 = BLM_PIPE(cpu_transcoder);
555 	intel_de_write(dev_priv, BLC_PWM_CPU_CTL2, cpu_ctl2);
556 	intel_de_posting_read(dev_priv, BLC_PWM_CPU_CTL2);
557 	intel_de_write(dev_priv, BLC_PWM_CPU_CTL2, cpu_ctl2 | BLM_PWM_ENABLE);
558 
559 	/* This won't stick until the above enable. */
560 	intel_backlight_set_pwm_level(conn_state, level);
561 
562 	pch_ctl2 = panel->backlight.pwm_level_max << 16;
563 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL2, pch_ctl2);
564 
565 	pch_ctl1 = 0;
566 	if (panel->backlight.active_low_pwm)
567 		pch_ctl1 |= BLM_PCH_POLARITY;
568 
569 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1, pch_ctl1);
570 	intel_de_posting_read(dev_priv, BLC_PWM_PCH_CTL1);
571 	intel_de_write(dev_priv, BLC_PWM_PCH_CTL1,
572 		       pch_ctl1 | BLM_PCH_PWM_ENABLE);
573 }
574 
575 static void i9xx_enable_backlight(const struct intel_crtc_state *crtc_state,
576 				  const struct drm_connector_state *conn_state, u32 level)
577 {
578 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
579 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
580 	struct intel_panel *panel = &connector->panel;
581 	u32 ctl, freq;
582 
583 	ctl = intel_de_read(dev_priv, BLC_PWM_CTL);
584 	if (ctl & BACKLIGHT_DUTY_CYCLE_MASK_PNV) {
585 		drm_dbg_kms(&dev_priv->drm, "backlight already enabled\n");
586 		intel_de_write(dev_priv, BLC_PWM_CTL, 0);
587 	}
588 
589 	freq = panel->backlight.pwm_level_max;
590 	if (panel->backlight.combination_mode)
591 		freq /= 0xff;
592 
593 	ctl = freq << 17;
594 	if (panel->backlight.combination_mode)
595 		ctl |= BLM_LEGACY_MODE;
596 	if (IS_PINEVIEW(dev_priv) && panel->backlight.active_low_pwm)
597 		ctl |= BLM_POLARITY_PNV;
598 
599 	intel_de_write(dev_priv, BLC_PWM_CTL, ctl);
600 	intel_de_posting_read(dev_priv, BLC_PWM_CTL);
601 
602 	/* XXX: combine this into above write? */
603 	intel_backlight_set_pwm_level(conn_state, level);
604 
605 	/*
606 	 * Needed to enable backlight on some 855gm models. BLC_HIST_CTL is
607 	 * 855gm only, but checking for gen2 is safe, as 855gm is the only gen2
608 	 * that has backlight.
609 	 */
610 	if (DISPLAY_VER(dev_priv) == 2)
611 		intel_de_write(dev_priv, BLC_HIST_CTL, BLM_HISTOGRAM_ENABLE);
612 }
613 
614 static void i965_enable_backlight(const struct intel_crtc_state *crtc_state,
615 				  const struct drm_connector_state *conn_state, u32 level)
616 {
617 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
618 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
619 	struct intel_panel *panel = &connector->panel;
620 	enum pipe pipe = to_intel_crtc(conn_state->crtc)->pipe;
621 	u32 ctl, ctl2, freq;
622 
623 	ctl2 = intel_de_read(dev_priv, BLC_PWM_CTL2);
624 	if (ctl2 & BLM_PWM_ENABLE) {
625 		drm_dbg_kms(&dev_priv->drm, "backlight already enabled\n");
626 		ctl2 &= ~BLM_PWM_ENABLE;
627 		intel_de_write(dev_priv, BLC_PWM_CTL2, ctl2);
628 	}
629 
630 	freq = panel->backlight.pwm_level_max;
631 	if (panel->backlight.combination_mode)
632 		freq /= 0xff;
633 
634 	ctl = freq << 16;
635 	intel_de_write(dev_priv, BLC_PWM_CTL, ctl);
636 
637 	ctl2 = BLM_PIPE(pipe);
638 	if (panel->backlight.combination_mode)
639 		ctl2 |= BLM_COMBINATION_MODE;
640 	if (panel->backlight.active_low_pwm)
641 		ctl2 |= BLM_POLARITY_I965;
642 	intel_de_write(dev_priv, BLC_PWM_CTL2, ctl2);
643 	intel_de_posting_read(dev_priv, BLC_PWM_CTL2);
644 	intel_de_write(dev_priv, BLC_PWM_CTL2, ctl2 | BLM_PWM_ENABLE);
645 
646 	intel_backlight_set_pwm_level(conn_state, level);
647 }
648 
649 static void vlv_enable_backlight(const struct intel_crtc_state *crtc_state,
650 				 const struct drm_connector_state *conn_state, u32 level)
651 {
652 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
653 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
654 	struct intel_panel *panel = &connector->panel;
655 	enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
656 	u32 ctl, ctl2;
657 
658 	ctl2 = intel_de_read(dev_priv, VLV_BLC_PWM_CTL2(pipe));
659 	if (ctl2 & BLM_PWM_ENABLE) {
660 		drm_dbg_kms(&dev_priv->drm, "backlight already enabled\n");
661 		ctl2 &= ~BLM_PWM_ENABLE;
662 		intel_de_write(dev_priv, VLV_BLC_PWM_CTL2(pipe), ctl2);
663 	}
664 
665 	ctl = panel->backlight.pwm_level_max << 16;
666 	intel_de_write(dev_priv, VLV_BLC_PWM_CTL(pipe), ctl);
667 
668 	/* XXX: combine this into above write? */
669 	intel_backlight_set_pwm_level(conn_state, level);
670 
671 	ctl2 = 0;
672 	if (panel->backlight.active_low_pwm)
673 		ctl2 |= BLM_POLARITY_I965;
674 	intel_de_write(dev_priv, VLV_BLC_PWM_CTL2(pipe), ctl2);
675 	intel_de_posting_read(dev_priv, VLV_BLC_PWM_CTL2(pipe));
676 	intel_de_write(dev_priv, VLV_BLC_PWM_CTL2(pipe),
677 		       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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
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(dev_priv, UTIL_PIN_CTL);
692 		if (val & UTIL_PIN_ENABLE) {
693 			drm_dbg_kms(&dev_priv->drm,
694 				    "util pin already enabled\n");
695 			val &= ~UTIL_PIN_ENABLE;
696 			intel_de_write(dev_priv, UTIL_PIN_CTL, val);
697 		}
698 
699 		val = 0;
700 		if (panel->backlight.util_pin_active_low)
701 			val |= UTIL_PIN_POLARITY;
702 		intel_de_write(dev_priv, UTIL_PIN_CTL,
703 			       val | UTIL_PIN_PIPE(pipe) | UTIL_PIN_MODE_PWM | UTIL_PIN_ENABLE);
704 	}
705 
706 	pwm_ctl = intel_de_read(dev_priv,
707 				BXT_BLC_PWM_CTL(panel->backlight.controller));
708 	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
709 		drm_dbg_kms(&dev_priv->drm, "backlight already enabled\n");
710 		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
711 		intel_de_write(dev_priv,
712 			       BXT_BLC_PWM_CTL(panel->backlight.controller),
713 			       pwm_ctl);
714 	}
715 
716 	intel_de_write(dev_priv,
717 		       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(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
727 		       pwm_ctl);
728 	intel_de_posting_read(dev_priv,
729 			      BXT_BLC_PWM_CTL(panel->backlight.controller));
730 	intel_de_write(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
731 		       pwm_ctl | BXT_BLC_PWM_ENABLE);
732 }
733 
734 static void cnp_enable_backlight(const struct intel_crtc_state *crtc_state,
735 				 const struct drm_connector_state *conn_state, u32 level)
736 {
737 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
738 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
739 	struct intel_panel *panel = &connector->panel;
740 	u32 pwm_ctl;
741 
742 	pwm_ctl = intel_de_read(dev_priv,
743 				BXT_BLC_PWM_CTL(panel->backlight.controller));
744 	if (pwm_ctl & BXT_BLC_PWM_ENABLE) {
745 		drm_dbg_kms(&dev_priv->drm, "backlight already enabled\n");
746 		pwm_ctl &= ~BXT_BLC_PWM_ENABLE;
747 		intel_de_write(dev_priv,
748 			       BXT_BLC_PWM_CTL(panel->backlight.controller),
749 			       pwm_ctl);
750 	}
751 
752 	intel_de_write(dev_priv,
753 		       BXT_BLC_PWM_FREQ(panel->backlight.controller),
754 		       panel->backlight.pwm_level_max);
755 
756 	intel_backlight_set_pwm_level(conn_state, level);
757 
758 	pwm_ctl = 0;
759 	if (panel->backlight.active_low_pwm)
760 		pwm_ctl |= BXT_BLC_PWM_POLARITY;
761 
762 	intel_de_write(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
763 		       pwm_ctl);
764 	intel_de_posting_read(dev_priv,
765 			      BXT_BLC_PWM_CTL(panel->backlight.controller));
766 	intel_de_write(dev_priv, BXT_BLC_PWM_CTL(panel->backlight.controller),
767 		       pwm_ctl | BXT_BLC_PWM_ENABLE);
768 }
769 
770 static void ext_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
771 				     const struct drm_connector_state *conn_state, u32 level)
772 {
773 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
774 	struct intel_panel *panel = &connector->panel;
775 
776 	pwm_set_relative_duty_cycle(&panel->backlight.pwm_state, level, 100);
777 	panel->backlight.pwm_state.enabled = true;
778 	pwm_apply_state(panel->backlight.pwm, &panel->backlight.pwm_state);
779 }
780 
781 static void __intel_backlight_enable(const struct intel_crtc_state *crtc_state,
782 				     const struct drm_connector_state *conn_state)
783 {
784 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
785 	struct intel_panel *panel = &connector->panel;
786 
787 	WARN_ON(panel->backlight.max == 0);
788 
789 	if (panel->backlight.level <= panel->backlight.min) {
790 		panel->backlight.level = panel->backlight.max;
791 		if (panel->backlight.device)
792 			panel->backlight.device->props.brightness =
793 				scale_hw_to_user(connector,
794 						 panel->backlight.level,
795 						 panel->backlight.device->props.max_brightness);
796 	}
797 
798 	panel->backlight.funcs->enable(crtc_state, conn_state, panel->backlight.level);
799 	panel->backlight.enabled = true;
800 	if (panel->backlight.device)
801 		panel->backlight.device->props.power = FB_BLANK_UNBLANK;
802 }
803 
804 void intel_backlight_enable(const struct intel_crtc_state *crtc_state,
805 			    const struct drm_connector_state *conn_state)
806 {
807 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
808 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
809 	struct intel_panel *panel = &connector->panel;
810 	enum pipe pipe = to_intel_crtc(crtc_state->uapi.crtc)->pipe;
811 
812 	if (!panel->backlight.present)
813 		return;
814 
815 	drm_dbg_kms(&dev_priv->drm, "pipe %c\n", pipe_name(pipe));
816 
817 	mutex_lock(&dev_priv->backlight_lock);
818 
819 	__intel_backlight_enable(crtc_state, conn_state);
820 
821 	mutex_unlock(&dev_priv->backlight_lock);
822 }
823 
824 #if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
825 static u32 intel_panel_get_backlight(struct intel_connector *connector)
826 {
827 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
828 	struct intel_panel *panel = &connector->panel;
829 	u32 val = 0;
830 
831 	mutex_lock(&dev_priv->backlight_lock);
832 
833 	if (panel->backlight.enabled)
834 		val = panel->backlight.funcs->get(connector, intel_connector_get_pipe(connector));
835 
836 	mutex_unlock(&dev_priv->backlight_lock);
837 
838 	drm_dbg_kms(&dev_priv->drm, "get backlight PWM = %d\n", val);
839 	return val;
840 }
841 
842 /* Scale user_level in range [0..user_max] to [hw_min..hw_max]. */
843 static u32 scale_user_to_hw(struct intel_connector *connector,
844 			    u32 user_level, u32 user_max)
845 {
846 	struct intel_panel *panel = &connector->panel;
847 
848 	return scale(user_level, 0, user_max,
849 		     panel->backlight.min, panel->backlight.max);
850 }
851 
852 /* set backlight brightness to level in range [0..max], scaling wrt hw min */
853 static void intel_panel_set_backlight(const struct drm_connector_state *conn_state,
854 				      u32 user_level, u32 user_max)
855 {
856 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
857 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
858 	struct intel_panel *panel = &connector->panel;
859 	u32 hw_level;
860 
861 	if (!panel->backlight.present)
862 		return;
863 
864 	mutex_lock(&dev_priv->backlight_lock);
865 
866 	drm_WARN_ON(&dev_priv->drm, panel->backlight.max == 0);
867 
868 	hw_level = scale_user_to_hw(connector, user_level, user_max);
869 	panel->backlight.level = hw_level;
870 
871 	if (panel->backlight.enabled)
872 		intel_panel_actually_set_backlight(conn_state, hw_level);
873 
874 	mutex_unlock(&dev_priv->backlight_lock);
875 }
876 
877 static int intel_backlight_device_update_status(struct backlight_device *bd)
878 {
879 	struct intel_connector *connector = bl_get_data(bd);
880 	struct intel_panel *panel = &connector->panel;
881 	struct drm_device *dev = connector->base.dev;
882 
883 	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
884 	DRM_DEBUG_KMS("updating intel_backlight, brightness=%d/%d\n",
885 		      bd->props.brightness, bd->props.max_brightness);
886 	intel_panel_set_backlight(connector->base.state, bd->props.brightness,
887 				  bd->props.max_brightness);
888 
889 	/*
890 	 * Allow flipping bl_power as a sub-state of enabled. Sadly the
891 	 * backlight class device does not make it easy to differentiate
892 	 * between callbacks for brightness and bl_power, so our backlight_power
893 	 * callback needs to take this into account.
894 	 */
895 	if (panel->backlight.enabled) {
896 		if (panel->backlight.power) {
897 			bool enable = bd->props.power == FB_BLANK_UNBLANK &&
898 				bd->props.brightness != 0;
899 			panel->backlight.power(connector, enable);
900 		}
901 	} else {
902 		bd->props.power = FB_BLANK_POWERDOWN;
903 	}
904 
905 	drm_modeset_unlock(&dev->mode_config.connection_mutex);
906 	return 0;
907 }
908 
909 static int intel_backlight_device_get_brightness(struct backlight_device *bd)
910 {
911 	struct intel_connector *connector = bl_get_data(bd);
912 	struct drm_device *dev = connector->base.dev;
913 	struct drm_i915_private *dev_priv = to_i915(dev);
914 	intel_wakeref_t wakeref;
915 	int ret = 0;
916 
917 	with_intel_runtime_pm(&dev_priv->runtime_pm, wakeref) {
918 		u32 hw_level;
919 
920 		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
921 
922 		hw_level = intel_panel_get_backlight(connector);
923 		ret = scale_hw_to_user(connector,
924 				       hw_level, bd->props.max_brightness);
925 
926 		drm_modeset_unlock(&dev->mode_config.connection_mutex);
927 	}
928 
929 	return ret;
930 }
931 
932 static const struct backlight_ops intel_backlight_device_ops = {
933 	.update_status = intel_backlight_device_update_status,
934 	.get_brightness = intel_backlight_device_get_brightness,
935 };
936 
937 int intel_backlight_device_register(struct intel_connector *connector)
938 {
939 	struct drm_i915_private *i915 = to_i915(connector->base.dev);
940 	struct intel_panel *panel = &connector->panel;
941 	struct backlight_properties props;
942 	struct backlight_device *bd;
943 	const char *name;
944 	int ret = 0;
945 
946 	if (WARN_ON(panel->backlight.device))
947 		return -ENODEV;
948 
949 	if (!panel->backlight.present)
950 		return 0;
951 
952 	WARN_ON(panel->backlight.max == 0);
953 
954 	memset(&props, 0, sizeof(props));
955 	props.type = BACKLIGHT_RAW;
956 
957 	/*
958 	 * Note: Everything should work even if the backlight device max
959 	 * presented to the userspace is arbitrarily chosen.
960 	 */
961 	props.max_brightness = panel->backlight.max;
962 	props.brightness = scale_hw_to_user(connector,
963 					    panel->backlight.level,
964 					    props.max_brightness);
965 
966 	if (panel->backlight.enabled)
967 		props.power = FB_BLANK_UNBLANK;
968 	else
969 		props.power = FB_BLANK_POWERDOWN;
970 
971 	name = kstrdup("intel_backlight", GFP_KERNEL);
972 	if (!name)
973 		return -ENOMEM;
974 
975 	bd = backlight_device_get_by_name(name);
976 	if (bd) {
977 		put_device(&bd->dev);
978 		/*
979 		 * Using the same name independent of the drm device or connector
980 		 * prevents registration of multiple backlight devices in the
981 		 * driver. However, we need to use the default name for backward
982 		 * compatibility. Use unique names for subsequent backlight devices as a
983 		 * fallback when the default name already exists.
984 		 */
985 		kfree(name);
986 		name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
987 				 i915->drm.primary->index, 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(&i915->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(&i915->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1032 
1033 	return DIV_ROUND_CLOSEST(KHz(RUNTIME_INFO(dev_priv)->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
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(dev_priv))
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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1094 
1095 	return DIV_ROUND_CLOSEST(KHz(RUNTIME_INFO(dev_priv)->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1110 	int clock;
1111 
1112 	if (IS_PINEVIEW(dev_priv))
1113 		clock = KHz(RUNTIME_INFO(dev_priv)->rawclk_freq);
1114 	else
1115 		clock = KHz(dev_priv->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1128 	int clock;
1129 
1130 	if (IS_G4X(dev_priv))
1131 		clock = KHz(RUNTIME_INFO(dev_priv)->rawclk_freq);
1132 	else
1133 		clock = KHz(dev_priv->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1146 	int mul, clock;
1147 
1148 	if ((intel_de_read(dev_priv, CBR1_VLV) & CBR_PWM_CLOCK_MUX_SELECT) == 0) {
1149 		if (IS_CHERRYVIEW(dev_priv))
1150 			clock = KHz(19200);
1151 		else
1152 			clock = MHz(25);
1153 		mul = 16;
1154 	} else {
1155 		clock = KHz(RUNTIME_INFO(dev_priv)->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1165 	u16 pwm_freq_hz = connector->panel.vbt.backlight.pwm_freq_hz;
1166 
1167 	if (pwm_freq_hz) {
1168 		drm_dbg_kms(&dev_priv->drm,
1169 			    "VBT defined backlight frequency %u Hz\n",
1170 			    pwm_freq_hz);
1171 	} else {
1172 		pwm_freq_hz = 200;
1173 		drm_dbg_kms(&dev_priv->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
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(&dev_priv->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(&dev_priv->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
1210 	struct intel_panel *panel = &connector->panel;
1211 	int min;
1212 
1213 	drm_WARN_ON(&dev_priv->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(&dev_priv->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 drm_i915_private *dev_priv = to_i915(connector->base.dev);
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(dev_priv))
1241 		alt = intel_de_read(dev_priv, SOUTH_CHICKEN2) & LPT_PWM_GRANULARITY;
1242 	else
1243 		alt = intel_de_read(dev_priv, SOUTH_CHICKEN1) & SPT_PWM_GRANULARITY;
1244 	panel->backlight.alternate_pwm_increment = alt;
1245 
1246 	pch_ctl1 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
1247 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1248 
1249 	pch_ctl2 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL2);
1250 	panel->backlight.pwm_level_max = pch_ctl2 >> 16;
1251 
1252 	cpu_ctl2 = intel_de_read(dev_priv, 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(dev_priv) &&
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(&dev_priv->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(dev_priv, BLC_PWM_PCH_CTL1,
1277 			       pch_ctl1 | BLM_PCH_OVERRIDE_ENABLE);
1278 
1279 		intel_de_write(dev_priv, BLC_PWM_CPU_CTL2,
1280 			       cpu_ctl2 & ~BLM_PWM_ENABLE);
1281 	}
1282 
1283 	return 0;
1284 }
1285 
1286 static int pch_setup_backlight(struct intel_connector *connector, enum pipe unused)
1287 {
1288 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1289 	struct intel_panel *panel = &connector->panel;
1290 	u32 cpu_ctl2, pch_ctl1, pch_ctl2;
1291 
1292 	pch_ctl1 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL1);
1293 	panel->backlight.active_low_pwm = pch_ctl1 & BLM_PCH_POLARITY;
1294 
1295 	pch_ctl2 = intel_de_read(dev_priv, BLC_PWM_PCH_CTL2);
1296 	panel->backlight.pwm_level_max = pch_ctl2 >> 16;
1297 
1298 	if (!panel->backlight.pwm_level_max)
1299 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1300 
1301 	if (!panel->backlight.pwm_level_max)
1302 		return -ENODEV;
1303 
1304 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1305 
1306 	cpu_ctl2 = intel_de_read(dev_priv, BLC_PWM_CPU_CTL2);
1307 	panel->backlight.pwm_enabled = (cpu_ctl2 & BLM_PWM_ENABLE) &&
1308 		(pch_ctl1 & BLM_PCH_PWM_ENABLE);
1309 
1310 	return 0;
1311 }
1312 
1313 static int i9xx_setup_backlight(struct intel_connector *connector, enum pipe unused)
1314 {
1315 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1316 	struct intel_panel *panel = &connector->panel;
1317 	u32 ctl, val;
1318 
1319 	ctl = intel_de_read(dev_priv, BLC_PWM_CTL);
1320 
1321 	if (DISPLAY_VER(dev_priv) == 2 || IS_I915GM(dev_priv) || IS_I945GM(dev_priv))
1322 		panel->backlight.combination_mode = ctl & BLM_LEGACY_MODE;
1323 
1324 	if (IS_PINEVIEW(dev_priv))
1325 		panel->backlight.active_low_pwm = ctl & BLM_POLARITY_PNV;
1326 
1327 	panel->backlight.pwm_level_max = ctl >> 17;
1328 
1329 	if (!panel->backlight.pwm_level_max) {
1330 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1331 		panel->backlight.pwm_level_max >>= 1;
1332 	}
1333 
1334 	if (!panel->backlight.pwm_level_max)
1335 		return -ENODEV;
1336 
1337 	if (panel->backlight.combination_mode)
1338 		panel->backlight.pwm_level_max *= 0xff;
1339 
1340 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1341 
1342 	val = i9xx_get_backlight(connector, unused);
1343 	val = intel_backlight_invert_pwm_level(connector, val);
1344 	val = clamp(val, panel->backlight.pwm_level_min, panel->backlight.pwm_level_max);
1345 
1346 	panel->backlight.pwm_enabled = val != 0;
1347 
1348 	return 0;
1349 }
1350 
1351 static int i965_setup_backlight(struct intel_connector *connector, enum pipe unused)
1352 {
1353 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1354 	struct intel_panel *panel = &connector->panel;
1355 	u32 ctl, ctl2;
1356 
1357 	ctl2 = intel_de_read(dev_priv, BLC_PWM_CTL2);
1358 	panel->backlight.combination_mode = ctl2 & BLM_COMBINATION_MODE;
1359 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1360 
1361 	ctl = intel_de_read(dev_priv, BLC_PWM_CTL);
1362 	panel->backlight.pwm_level_max = ctl >> 16;
1363 
1364 	if (!panel->backlight.pwm_level_max)
1365 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1366 
1367 	if (!panel->backlight.pwm_level_max)
1368 		return -ENODEV;
1369 
1370 	if (panel->backlight.combination_mode)
1371 		panel->backlight.pwm_level_max *= 0xff;
1372 
1373 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1374 
1375 	panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
1376 
1377 	return 0;
1378 }
1379 
1380 static int vlv_setup_backlight(struct intel_connector *connector, enum pipe pipe)
1381 {
1382 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1383 	struct intel_panel *panel = &connector->panel;
1384 	u32 ctl, ctl2;
1385 
1386 	if (drm_WARN_ON(&dev_priv->drm, pipe != PIPE_A && pipe != PIPE_B))
1387 		return -ENODEV;
1388 
1389 	ctl2 = intel_de_read(dev_priv, VLV_BLC_PWM_CTL2(pipe));
1390 	panel->backlight.active_low_pwm = ctl2 & BLM_POLARITY_I965;
1391 
1392 	ctl = intel_de_read(dev_priv, VLV_BLC_PWM_CTL(pipe));
1393 	panel->backlight.pwm_level_max = ctl >> 16;
1394 
1395 	if (!panel->backlight.pwm_level_max)
1396 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1397 
1398 	if (!panel->backlight.pwm_level_max)
1399 		return -ENODEV;
1400 
1401 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1402 
1403 	panel->backlight.pwm_enabled = ctl2 & BLM_PWM_ENABLE;
1404 
1405 	return 0;
1406 }
1407 
1408 static int
1409 bxt_setup_backlight(struct intel_connector *connector, enum pipe unused)
1410 {
1411 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1412 	struct intel_panel *panel = &connector->panel;
1413 	u32 pwm_ctl, val;
1414 
1415 	panel->backlight.controller = connector->panel.vbt.backlight.controller;
1416 
1417 	pwm_ctl = intel_de_read(dev_priv,
1418 				BXT_BLC_PWM_CTL(panel->backlight.controller));
1419 
1420 	/* Controller 1 uses the utility pin. */
1421 	if (panel->backlight.controller == 1) {
1422 		val = intel_de_read(dev_priv, UTIL_PIN_CTL);
1423 		panel->backlight.util_pin_active_low =
1424 					val & UTIL_PIN_POLARITY;
1425 	}
1426 
1427 	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
1428 	panel->backlight.pwm_level_max =
1429 		intel_de_read(dev_priv, BXT_BLC_PWM_FREQ(panel->backlight.controller));
1430 
1431 	if (!panel->backlight.pwm_level_max)
1432 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1433 
1434 	if (!panel->backlight.pwm_level_max)
1435 		return -ENODEV;
1436 
1437 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1438 
1439 	panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
1440 
1441 	return 0;
1442 }
1443 
1444 static int
1445 cnp_setup_backlight(struct intel_connector *connector, enum pipe unused)
1446 {
1447 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1448 	struct intel_panel *panel = &connector->panel;
1449 	u32 pwm_ctl;
1450 
1451 	/*
1452 	 * CNP has the BXT implementation of backlight, but with only one
1453 	 * controller. TODO: ICP has multiple controllers but we only use
1454 	 * controller 0 for now.
1455 	 */
1456 	panel->backlight.controller = 0;
1457 
1458 	pwm_ctl = intel_de_read(dev_priv,
1459 				BXT_BLC_PWM_CTL(panel->backlight.controller));
1460 
1461 	panel->backlight.active_low_pwm = pwm_ctl & BXT_BLC_PWM_POLARITY;
1462 	panel->backlight.pwm_level_max =
1463 		intel_de_read(dev_priv, BXT_BLC_PWM_FREQ(panel->backlight.controller));
1464 
1465 	if (!panel->backlight.pwm_level_max)
1466 		panel->backlight.pwm_level_max = get_backlight_max_vbt(connector);
1467 
1468 	if (!panel->backlight.pwm_level_max)
1469 		return -ENODEV;
1470 
1471 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1472 
1473 	panel->backlight.pwm_enabled = pwm_ctl & BXT_BLC_PWM_ENABLE;
1474 
1475 	return 0;
1476 }
1477 
1478 static int ext_pwm_setup_backlight(struct intel_connector *connector,
1479 				   enum pipe pipe)
1480 {
1481 	struct drm_device *dev = connector->base.dev;
1482 	struct drm_i915_private *dev_priv = to_i915(dev);
1483 	struct intel_panel *panel = &connector->panel;
1484 	const char *desc;
1485 	u32 level;
1486 
1487 	/* Get the right PWM chip for DSI backlight according to VBT */
1488 	if (connector->panel.vbt.dsi.config->pwm_blc == PPS_BLC_PMIC) {
1489 		panel->backlight.pwm = pwm_get(dev->dev, "pwm_pmic_backlight");
1490 		desc = "PMIC";
1491 	} else {
1492 		panel->backlight.pwm = pwm_get(dev->dev, "pwm_soc_backlight");
1493 		desc = "SoC";
1494 	}
1495 
1496 	if (IS_ERR(panel->backlight.pwm)) {
1497 		drm_err(&dev_priv->drm, "Failed to get the %s PWM chip\n",
1498 			desc);
1499 		panel->backlight.pwm = NULL;
1500 		return -ENODEV;
1501 	}
1502 
1503 	panel->backlight.pwm_level_max = 100; /* 100% */
1504 	panel->backlight.pwm_level_min = get_backlight_min_vbt(connector);
1505 
1506 	if (pwm_is_enabled(panel->backlight.pwm)) {
1507 		/* PWM is already enabled, use existing settings */
1508 		pwm_get_state(panel->backlight.pwm, &panel->backlight.pwm_state);
1509 
1510 		level = pwm_get_relative_duty_cycle(&panel->backlight.pwm_state,
1511 						    100);
1512 		level = intel_backlight_invert_pwm_level(connector, level);
1513 		panel->backlight.pwm_enabled = true;
1514 
1515 		drm_dbg_kms(&dev_priv->drm, "PWM already enabled at freq %ld, VBT freq %d, level %d\n",
1516 			    NSEC_PER_SEC / (unsigned long)panel->backlight.pwm_state.period,
1517 			    get_vbt_pwm_freq(connector), level);
1518 	} else {
1519 		/* Set period from VBT frequency, leave other settings at 0. */
1520 		panel->backlight.pwm_state.period =
1521 			NSEC_PER_SEC / get_vbt_pwm_freq(connector);
1522 	}
1523 
1524 	drm_info(&dev_priv->drm, "Using %s PWM for LCD backlight control\n",
1525 		 desc);
1526 	return 0;
1527 }
1528 
1529 static void intel_pwm_set_backlight(const struct drm_connector_state *conn_state, u32 level)
1530 {
1531 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1532 	struct intel_panel *panel = &connector->panel;
1533 
1534 	panel->backlight.pwm_funcs->set(conn_state,
1535 					intel_backlight_invert_pwm_level(connector, level));
1536 }
1537 
1538 static u32 intel_pwm_get_backlight(struct intel_connector *connector, enum pipe pipe)
1539 {
1540 	struct intel_panel *panel = &connector->panel;
1541 
1542 	return intel_backlight_invert_pwm_level(connector,
1543 					    panel->backlight.pwm_funcs->get(connector, pipe));
1544 }
1545 
1546 static void intel_pwm_enable_backlight(const struct intel_crtc_state *crtc_state,
1547 				       const struct drm_connector_state *conn_state, u32 level)
1548 {
1549 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1550 	struct intel_panel *panel = &connector->panel;
1551 
1552 	panel->backlight.pwm_funcs->enable(crtc_state, conn_state,
1553 					   intel_backlight_invert_pwm_level(connector, level));
1554 }
1555 
1556 static void intel_pwm_disable_backlight(const struct drm_connector_state *conn_state, u32 level)
1557 {
1558 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1559 	struct intel_panel *panel = &connector->panel;
1560 
1561 	panel->backlight.pwm_funcs->disable(conn_state,
1562 					    intel_backlight_invert_pwm_level(connector, level));
1563 }
1564 
1565 static int intel_pwm_setup_backlight(struct intel_connector *connector, enum pipe pipe)
1566 {
1567 	struct intel_panel *panel = &connector->panel;
1568 	int ret = panel->backlight.pwm_funcs->setup(connector, pipe);
1569 
1570 	if (ret < 0)
1571 		return ret;
1572 
1573 	panel->backlight.min = panel->backlight.pwm_level_min;
1574 	panel->backlight.max = panel->backlight.pwm_level_max;
1575 	panel->backlight.level = intel_pwm_get_backlight(connector, pipe);
1576 	panel->backlight.enabled = panel->backlight.pwm_enabled;
1577 
1578 	return 0;
1579 }
1580 
1581 void intel_backlight_update(struct intel_atomic_state *state,
1582 			    struct intel_encoder *encoder,
1583 			    const struct intel_crtc_state *crtc_state,
1584 			    const struct drm_connector_state *conn_state)
1585 {
1586 	struct intel_connector *connector = to_intel_connector(conn_state->connector);
1587 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1588 	struct intel_panel *panel = &connector->panel;
1589 
1590 	if (!panel->backlight.present)
1591 		return;
1592 
1593 	mutex_lock(&dev_priv->backlight_lock);
1594 	if (!panel->backlight.enabled)
1595 		__intel_backlight_enable(crtc_state, conn_state);
1596 
1597 	mutex_unlock(&dev_priv->backlight_lock);
1598 }
1599 
1600 int intel_backlight_setup(struct intel_connector *connector, enum pipe pipe)
1601 {
1602 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1603 	struct intel_panel *panel = &connector->panel;
1604 	int ret;
1605 
1606 	if (!connector->panel.vbt.backlight.present) {
1607 		if (dev_priv->quirks & QUIRK_BACKLIGHT_PRESENT) {
1608 			drm_dbg_kms(&dev_priv->drm,
1609 				    "no backlight present per VBT, but present per quirk\n");
1610 		} else {
1611 			drm_dbg_kms(&dev_priv->drm,
1612 				    "no backlight present per VBT\n");
1613 			return 0;
1614 		}
1615 	}
1616 
1617 	/* ensure intel_panel has been initialized first */
1618 	if (drm_WARN_ON(&dev_priv->drm, !panel->backlight.funcs))
1619 		return -ENODEV;
1620 
1621 	/* set level and max in panel struct */
1622 	mutex_lock(&dev_priv->backlight_lock);
1623 	ret = panel->backlight.funcs->setup(connector, pipe);
1624 	mutex_unlock(&dev_priv->backlight_lock);
1625 
1626 	if (ret) {
1627 		drm_dbg_kms(&dev_priv->drm,
1628 			    "failed to setup backlight for connector %s\n",
1629 			    connector->base.name);
1630 		return ret;
1631 	}
1632 
1633 	panel->backlight.present = true;
1634 
1635 	drm_dbg_kms(&dev_priv->drm,
1636 		    "Connector %s backlight initialized, %s, brightness %u/%u\n",
1637 		    connector->base.name,
1638 		    str_enabled_disabled(panel->backlight.enabled),
1639 		    panel->backlight.level, panel->backlight.max);
1640 
1641 	return 0;
1642 }
1643 
1644 void intel_backlight_destroy(struct intel_panel *panel)
1645 {
1646 	/* dispose of the pwm */
1647 	if (panel->backlight.pwm)
1648 		pwm_put(panel->backlight.pwm);
1649 
1650 	panel->backlight.present = false;
1651 }
1652 
1653 static const struct intel_panel_bl_funcs bxt_pwm_funcs = {
1654 	.setup = bxt_setup_backlight,
1655 	.enable = bxt_enable_backlight,
1656 	.disable = bxt_disable_backlight,
1657 	.set = bxt_set_backlight,
1658 	.get = bxt_get_backlight,
1659 	.hz_to_pwm = bxt_hz_to_pwm,
1660 };
1661 
1662 static const struct intel_panel_bl_funcs cnp_pwm_funcs = {
1663 	.setup = cnp_setup_backlight,
1664 	.enable = cnp_enable_backlight,
1665 	.disable = cnp_disable_backlight,
1666 	.set = bxt_set_backlight,
1667 	.get = bxt_get_backlight,
1668 	.hz_to_pwm = cnp_hz_to_pwm,
1669 };
1670 
1671 static const struct intel_panel_bl_funcs lpt_pwm_funcs = {
1672 	.setup = lpt_setup_backlight,
1673 	.enable = lpt_enable_backlight,
1674 	.disable = lpt_disable_backlight,
1675 	.set = lpt_set_backlight,
1676 	.get = lpt_get_backlight,
1677 	.hz_to_pwm = lpt_hz_to_pwm,
1678 };
1679 
1680 static const struct intel_panel_bl_funcs spt_pwm_funcs = {
1681 	.setup = lpt_setup_backlight,
1682 	.enable = lpt_enable_backlight,
1683 	.disable = lpt_disable_backlight,
1684 	.set = lpt_set_backlight,
1685 	.get = lpt_get_backlight,
1686 	.hz_to_pwm = spt_hz_to_pwm,
1687 };
1688 
1689 static const struct intel_panel_bl_funcs pch_pwm_funcs = {
1690 	.setup = pch_setup_backlight,
1691 	.enable = pch_enable_backlight,
1692 	.disable = pch_disable_backlight,
1693 	.set = pch_set_backlight,
1694 	.get = pch_get_backlight,
1695 	.hz_to_pwm = pch_hz_to_pwm,
1696 };
1697 
1698 static const struct intel_panel_bl_funcs ext_pwm_funcs = {
1699 	.setup = ext_pwm_setup_backlight,
1700 	.enable = ext_pwm_enable_backlight,
1701 	.disable = ext_pwm_disable_backlight,
1702 	.set = ext_pwm_set_backlight,
1703 	.get = ext_pwm_get_backlight,
1704 };
1705 
1706 static const struct intel_panel_bl_funcs vlv_pwm_funcs = {
1707 	.setup = vlv_setup_backlight,
1708 	.enable = vlv_enable_backlight,
1709 	.disable = vlv_disable_backlight,
1710 	.set = vlv_set_backlight,
1711 	.get = vlv_get_backlight,
1712 	.hz_to_pwm = vlv_hz_to_pwm,
1713 };
1714 
1715 static const struct intel_panel_bl_funcs i965_pwm_funcs = {
1716 	.setup = i965_setup_backlight,
1717 	.enable = i965_enable_backlight,
1718 	.disable = i965_disable_backlight,
1719 	.set = i9xx_set_backlight,
1720 	.get = i9xx_get_backlight,
1721 	.hz_to_pwm = i965_hz_to_pwm,
1722 };
1723 
1724 static const struct intel_panel_bl_funcs i9xx_pwm_funcs = {
1725 	.setup = i9xx_setup_backlight,
1726 	.enable = i9xx_enable_backlight,
1727 	.disable = i9xx_disable_backlight,
1728 	.set = i9xx_set_backlight,
1729 	.get = i9xx_get_backlight,
1730 	.hz_to_pwm = i9xx_hz_to_pwm,
1731 };
1732 
1733 static const struct intel_panel_bl_funcs pwm_bl_funcs = {
1734 	.setup = intel_pwm_setup_backlight,
1735 	.enable = intel_pwm_enable_backlight,
1736 	.disable = intel_pwm_disable_backlight,
1737 	.set = intel_pwm_set_backlight,
1738 	.get = intel_pwm_get_backlight,
1739 };
1740 
1741 /* Set up chip specific backlight functions */
1742 void intel_backlight_init_funcs(struct intel_panel *panel)
1743 {
1744 	struct intel_connector *connector =
1745 		container_of(panel, struct intel_connector, panel);
1746 	struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
1747 
1748 	if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI &&
1749 	    intel_dsi_dcs_init_backlight_funcs(connector) == 0)
1750 		return;
1751 
1752 	if (IS_GEMINILAKE(dev_priv) || IS_BROXTON(dev_priv)) {
1753 		panel->backlight.pwm_funcs = &bxt_pwm_funcs;
1754 	} else if (INTEL_PCH_TYPE(dev_priv) >= PCH_CNP) {
1755 		panel->backlight.pwm_funcs = &cnp_pwm_funcs;
1756 	} else if (INTEL_PCH_TYPE(dev_priv) >= PCH_LPT) {
1757 		if (HAS_PCH_LPT(dev_priv))
1758 			panel->backlight.pwm_funcs = &lpt_pwm_funcs;
1759 		else
1760 			panel->backlight.pwm_funcs = &spt_pwm_funcs;
1761 	} else if (HAS_PCH_SPLIT(dev_priv)) {
1762 		panel->backlight.pwm_funcs = &pch_pwm_funcs;
1763 	} else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv)) {
1764 		if (connector->base.connector_type == DRM_MODE_CONNECTOR_DSI) {
1765 			panel->backlight.pwm_funcs = &ext_pwm_funcs;
1766 		} else {
1767 			panel->backlight.pwm_funcs = &vlv_pwm_funcs;
1768 		}
1769 	} else if (DISPLAY_VER(dev_priv) == 4) {
1770 		panel->backlight.pwm_funcs = &i965_pwm_funcs;
1771 	} else {
1772 		panel->backlight.pwm_funcs = &i9xx_pwm_funcs;
1773 	}
1774 
1775 	if (connector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
1776 		if (intel_dp_aux_init_backlight_funcs(connector) == 0)
1777 			return;
1778 
1779 		if (!(dev_priv->quirks & QUIRK_NO_PPS_BACKLIGHT_POWER_HOOK))
1780 			connector->panel.backlight.power = intel_pps_backlight_power;
1781 	}
1782 
1783 	/* We're using a standard PWM backlight interface */
1784 	panel->backlight.funcs = &pwm_bl_funcs;
1785 }
1786