1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright(c) 2016, Analogix Semiconductor.
4  * Copyright(c) 2017, Icenowy Zheng <icenowy@aosc.io>
5  *
6  * Based on anx7808 driver obtained from chromeos with copyright:
7  * Copyright(c) 2013, Google Inc.
8  */
9 #include <linux/delay.h>
10 #include <linux/err.h>
11 #include <linux/gpio/consumer.h>
12 #include <linux/i2c.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/of_platform.h>
17 #include <linux/regmap.h>
18 #include <linux/regulator/consumer.h>
19 #include <linux/types.h>
20 
21 #include <drm/display/drm_dp_helper.h>
22 #include <drm/drm_atomic_helper.h>
23 #include <drm/drm_bridge.h>
24 #include <drm/drm_crtc.h>
25 #include <drm/drm_crtc_helper.h>
26 #include <drm/drm_edid.h>
27 #include <drm/drm_of.h>
28 #include <drm/drm_panel.h>
29 #include <drm/drm_print.h>
30 #include <drm/drm_probe_helper.h>
31 
32 #include "analogix-i2c-dptx.h"
33 #include "analogix-i2c-txcommon.h"
34 
35 #define POLL_DELAY		50000 /* us */
36 #define POLL_TIMEOUT		5000000 /* us */
37 
38 #define I2C_IDX_DPTX		0
39 #define I2C_IDX_TXCOM		1
40 
41 static const u8 anx6345_i2c_addresses[] = {
42 	[I2C_IDX_DPTX]	= 0x70,
43 	[I2C_IDX_TXCOM]	= 0x72,
44 };
45 #define I2C_NUM_ADDRESSES	ARRAY_SIZE(anx6345_i2c_addresses)
46 
47 struct anx6345 {
48 	struct drm_dp_aux aux;
49 	struct drm_bridge bridge;
50 	struct i2c_client *client;
51 	struct edid *edid;
52 	struct drm_connector connector;
53 	struct drm_panel *panel;
54 	struct regulator *dvdd12;
55 	struct regulator *dvdd25;
56 	struct gpio_desc *gpiod_reset;
57 	struct mutex lock;	/* protect EDID access */
58 
59 	/* I2C Slave addresses of ANX6345 are mapped as DPTX and SYS */
60 	struct i2c_client *i2c_clients[I2C_NUM_ADDRESSES];
61 	struct regmap *map[I2C_NUM_ADDRESSES];
62 
63 	u16 chipid;
64 	u8 dpcd[DP_RECEIVER_CAP_SIZE];
65 
66 	bool powered;
67 };
68 
69 static inline struct anx6345 *connector_to_anx6345(struct drm_connector *c)
70 {
71 	return container_of(c, struct anx6345, connector);
72 }
73 
74 static inline struct anx6345 *bridge_to_anx6345(struct drm_bridge *bridge)
75 {
76 	return container_of(bridge, struct anx6345, bridge);
77 }
78 
79 static int anx6345_set_bits(struct regmap *map, u8 reg, u8 mask)
80 {
81 	return regmap_update_bits(map, reg, mask, mask);
82 }
83 
84 static int anx6345_clear_bits(struct regmap *map, u8 reg, u8 mask)
85 {
86 	return regmap_update_bits(map, reg, mask, 0);
87 }
88 
89 static ssize_t anx6345_aux_transfer(struct drm_dp_aux *aux,
90 				    struct drm_dp_aux_msg *msg)
91 {
92 	struct anx6345 *anx6345 = container_of(aux, struct anx6345, aux);
93 
94 	return anx_dp_aux_transfer(anx6345->map[I2C_IDX_DPTX], msg);
95 }
96 
97 static int anx6345_dp_link_training(struct anx6345 *anx6345)
98 {
99 	unsigned int value;
100 	u8 dp_bw, dpcd[2];
101 	int err;
102 
103 	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
104 				 SP_POWERDOWN_CTRL_REG,
105 				 SP_TOTAL_PD);
106 	if (err)
107 		return err;
108 
109 	err = drm_dp_dpcd_readb(&anx6345->aux, DP_MAX_LINK_RATE, &dp_bw);
110 	if (err < 0)
111 		return err;
112 
113 	switch (dp_bw) {
114 	case DP_LINK_BW_1_62:
115 	case DP_LINK_BW_2_7:
116 		break;
117 
118 	default:
119 		DRM_DEBUG_KMS("DP bandwidth (%#02x) not supported\n", dp_bw);
120 		return -EINVAL;
121 	}
122 
123 	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
124 			       SP_VIDEO_MUTE);
125 	if (err)
126 		return err;
127 
128 	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
129 				 SP_VID_CTRL1_REG, SP_VIDEO_EN);
130 	if (err)
131 		return err;
132 
133 	/* Get DPCD info */
134 	err = drm_dp_dpcd_read(&anx6345->aux, DP_DPCD_REV,
135 			       &anx6345->dpcd, DP_RECEIVER_CAP_SIZE);
136 	if (err < 0) {
137 		DRM_ERROR("Failed to read DPCD: %d\n", err);
138 		return err;
139 	}
140 
141 	/* Clear channel x SERDES power down */
142 	err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
143 				 SP_DP_ANALOG_POWER_DOWN_REG, SP_CH0_PD);
144 	if (err)
145 		return err;
146 
147 	/*
148 	 * Power up the sink (DP_SET_POWER register is only available on DPCD
149 	 * v1.1 and later).
150 	 */
151 	if (anx6345->dpcd[DP_DPCD_REV] >= 0x11) {
152 		err = drm_dp_dpcd_readb(&anx6345->aux, DP_SET_POWER, &dpcd[0]);
153 		if (err < 0) {
154 			DRM_ERROR("Failed to read DP_SET_POWER register: %d\n",
155 				  err);
156 			return err;
157 		}
158 
159 		dpcd[0] &= ~DP_SET_POWER_MASK;
160 		dpcd[0] |= DP_SET_POWER_D0;
161 
162 		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_SET_POWER, dpcd[0]);
163 		if (err < 0) {
164 			DRM_ERROR("Failed to power up DisplayPort link: %d\n",
165 				  err);
166 			return err;
167 		}
168 
169 		/*
170 		 * According to the DP 1.1 specification, a "Sink Device must
171 		 * exit the power saving state within 1 ms" (Section 2.5.3.1,
172 		 * Table 5-52, "Sink Control Field" (register 0x600).
173 		 */
174 		usleep_range(1000, 2000);
175 	}
176 
177 	/* Possibly enable downspread on the sink */
178 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
179 			   SP_DP_DOWNSPREAD_CTRL1_REG, 0);
180 	if (err)
181 		return err;
182 
183 	if (anx6345->dpcd[DP_MAX_DOWNSPREAD] & DP_MAX_DOWNSPREAD_0_5) {
184 		DRM_DEBUG("Enable downspread on the sink\n");
185 		/* 4000PPM */
186 		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
187 				   SP_DP_DOWNSPREAD_CTRL1_REG, 8);
188 		if (err)
189 			return err;
190 
191 		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL,
192 					 DP_SPREAD_AMP_0_5);
193 		if (err < 0)
194 			return err;
195 	} else {
196 		err = drm_dp_dpcd_writeb(&anx6345->aux, DP_DOWNSPREAD_CTRL, 0);
197 		if (err < 0)
198 			return err;
199 	}
200 
201 	/* Set the lane count and the link rate on the sink */
202 	if (drm_dp_enhanced_frame_cap(anx6345->dpcd))
203 		err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
204 				       SP_DP_SYSTEM_CTRL_BASE + 4,
205 				       SP_ENHANCED_MODE);
206 	else
207 		err = anx6345_clear_bits(anx6345->map[I2C_IDX_DPTX],
208 					 SP_DP_SYSTEM_CTRL_BASE + 4,
209 					 SP_ENHANCED_MODE);
210 	if (err)
211 		return err;
212 
213 	dpcd[0] = dp_bw;
214 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
215 			   SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]);
216 	if (err)
217 		return err;
218 
219 	dpcd[1] = drm_dp_max_lane_count(anx6345->dpcd);
220 
221 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
222 			   SP_DP_LANE_COUNT_SET_REG, dpcd[1]);
223 	if (err)
224 		return err;
225 
226 	if (drm_dp_enhanced_frame_cap(anx6345->dpcd))
227 		dpcd[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN;
228 
229 	err = drm_dp_dpcd_write(&anx6345->aux, DP_LINK_BW_SET, dpcd,
230 				sizeof(dpcd));
231 
232 	if (err < 0) {
233 		DRM_ERROR("Failed to configure link: %d\n", err);
234 		return err;
235 	}
236 
237 	/* Start training on the source */
238 	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_LT_CTRL_REG,
239 			   SP_LT_EN);
240 	if (err)
241 		return err;
242 
243 	return regmap_read_poll_timeout(anx6345->map[I2C_IDX_DPTX],
244 				       SP_DP_LT_CTRL_REG,
245 				       value, !(value & SP_DP_LT_INPROGRESS),
246 				       POLL_DELAY, POLL_TIMEOUT);
247 }
248 
249 static int anx6345_tx_initialization(struct anx6345 *anx6345)
250 {
251 	int err, i;
252 
253 	/* FIXME: colordepth is hardcoded for now */
254 	err = regmap_write(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL2_REG,
255 			   SP_IN_BPC_6BIT << SP_IN_BPC_SHIFT);
256 	if (err)
257 		return err;
258 
259 	err = regmap_write(anx6345->map[I2C_IDX_DPTX], SP_DP_PLL_CTRL_REG, 0);
260 	if (err)
261 		return err;
262 
263 	err = regmap_write(anx6345->map[I2C_IDX_TXCOM],
264 			   SP_ANALOG_DEBUG1_REG, 0);
265 	if (err)
266 		return err;
267 
268 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
269 			   SP_DP_LINK_DEBUG_CTRL_REG,
270 			   SP_NEW_PRBS7 | SP_M_VID_DEBUG);
271 	if (err)
272 		return err;
273 
274 	err = regmap_write(anx6345->map[I2C_IDX_DPTX],
275 			   SP_DP_ANALOG_POWER_DOWN_REG, 0);
276 	if (err)
277 		return err;
278 
279 	/* Force HPD */
280 	err = anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
281 			       SP_DP_SYSTEM_CTRL_BASE + 3,
282 			       SP_HPD_FORCE | SP_HPD_CTRL);
283 	if (err)
284 		return err;
285 
286 	for (i = 0; i < 4; i++) {
287 		/* 4 lanes */
288 		err = regmap_write(anx6345->map[I2C_IDX_DPTX],
289 				   SP_DP_LANE0_LT_CTRL_REG + i, 0);
290 		if (err)
291 			return err;
292 	}
293 
294 	/* Reset AUX */
295 	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM],
296 			       SP_RESET_CTRL2_REG, SP_AUX_RST);
297 	if (err)
298 		return err;
299 
300 	return anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
301 				 SP_RESET_CTRL2_REG, SP_AUX_RST);
302 }
303 
304 static void anx6345_poweron(struct anx6345 *anx6345)
305 {
306 	int err;
307 
308 	/* Ensure reset is asserted before starting power on sequence */
309 	gpiod_set_value_cansleep(anx6345->gpiod_reset, 1);
310 	usleep_range(1000, 2000);
311 
312 	err = regulator_enable(anx6345->dvdd12);
313 	if (err) {
314 		DRM_ERROR("Failed to enable dvdd12 regulator: %d\n",
315 			  err);
316 		return;
317 	}
318 
319 	/* T1 - delay between VDD12 and VDD25 should be 0-2ms */
320 	usleep_range(1000, 2000);
321 
322 	err = regulator_enable(anx6345->dvdd25);
323 	if (err) {
324 		DRM_ERROR("Failed to enable dvdd25 regulator: %d\n",
325 			  err);
326 		return;
327 	}
328 
329 	/* T2 - delay between RESETN and all power rail stable,
330 	 * should be 2-5ms
331 	 */
332 	usleep_range(2000, 5000);
333 
334 	gpiod_set_value_cansleep(anx6345->gpiod_reset, 0);
335 
336 	/* Power on registers module */
337 	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
338 			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
339 	anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
340 			   SP_REGISTER_PD | SP_TOTAL_PD);
341 
342 	if (anx6345->panel)
343 		drm_panel_prepare(anx6345->panel);
344 
345 	anx6345->powered = true;
346 }
347 
348 static void anx6345_poweroff(struct anx6345 *anx6345)
349 {
350 	int err;
351 
352 	gpiod_set_value_cansleep(anx6345->gpiod_reset, 1);
353 	usleep_range(1000, 2000);
354 
355 	if (anx6345->panel)
356 		drm_panel_unprepare(anx6345->panel);
357 
358 	err = regulator_disable(anx6345->dvdd25);
359 	if (err) {
360 		DRM_ERROR("Failed to disable dvdd25 regulator: %d\n",
361 			  err);
362 		return;
363 	}
364 
365 	usleep_range(5000, 10000);
366 
367 	err = regulator_disable(anx6345->dvdd12);
368 	if (err) {
369 		DRM_ERROR("Failed to disable dvdd12 regulator: %d\n",
370 			  err);
371 		return;
372 	}
373 
374 	usleep_range(1000, 2000);
375 
376 	anx6345->powered = false;
377 }
378 
379 static int anx6345_start(struct anx6345 *anx6345)
380 {
381 	int err;
382 
383 	if (!anx6345->powered)
384 		anx6345_poweron(anx6345);
385 
386 	/* Power on needed modules */
387 	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM],
388 				SP_POWERDOWN_CTRL_REG,
389 				SP_VIDEO_PD | SP_LINK_PD);
390 
391 	err = anx6345_tx_initialization(anx6345);
392 	if (err) {
393 		DRM_ERROR("Failed eDP transmitter initialization: %d\n", err);
394 		anx6345_poweroff(anx6345);
395 		return err;
396 	}
397 
398 	err = anx6345_dp_link_training(anx6345);
399 	if (err) {
400 		DRM_ERROR("Failed link training: %d\n", err);
401 		anx6345_poweroff(anx6345);
402 		return err;
403 	}
404 
405 	/*
406 	 * This delay seems to help keep the hardware in a good state. Without
407 	 * it, there are times where it fails silently.
408 	 */
409 	usleep_range(10000, 15000);
410 
411 	return 0;
412 }
413 
414 static int anx6345_config_dp_output(struct anx6345 *anx6345)
415 {
416 	int err;
417 
418 	err = anx6345_clear_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
419 				 SP_VIDEO_MUTE);
420 	if (err)
421 		return err;
422 
423 	/* Enable DP output */
424 	err = anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_VID_CTRL1_REG,
425 			       SP_VIDEO_EN);
426 	if (err)
427 		return err;
428 
429 	/* Force stream valid */
430 	return anx6345_set_bits(anx6345->map[I2C_IDX_DPTX],
431 			       SP_DP_SYSTEM_CTRL_BASE + 3,
432 			       SP_STRM_FORCE | SP_STRM_CTRL);
433 }
434 
435 static int anx6345_get_downstream_info(struct anx6345 *anx6345)
436 {
437 	u8 value;
438 	int err;
439 
440 	err = drm_dp_dpcd_readb(&anx6345->aux, DP_SINK_COUNT, &value);
441 	if (err < 0) {
442 		DRM_ERROR("Get sink count failed %d\n", err);
443 		return err;
444 	}
445 
446 	if (!DP_GET_SINK_COUNT(value)) {
447 		DRM_ERROR("Downstream disconnected\n");
448 		return -EIO;
449 	}
450 
451 	return 0;
452 }
453 
454 static int anx6345_get_modes(struct drm_connector *connector)
455 {
456 	struct anx6345 *anx6345 = connector_to_anx6345(connector);
457 	int err, num_modes = 0;
458 	bool power_off = false;
459 
460 	mutex_lock(&anx6345->lock);
461 
462 	if (!anx6345->edid) {
463 		if (!anx6345->powered) {
464 			anx6345_poweron(anx6345);
465 			power_off = true;
466 		}
467 
468 		err = anx6345_get_downstream_info(anx6345);
469 		if (err) {
470 			DRM_ERROR("Failed to get downstream info: %d\n", err);
471 			goto unlock;
472 		}
473 
474 		anx6345->edid = drm_get_edid(connector, &anx6345->aux.ddc);
475 		if (!anx6345->edid)
476 			DRM_ERROR("Failed to read EDID from panel\n");
477 
478 		err = drm_connector_update_edid_property(connector,
479 							 anx6345->edid);
480 		if (err) {
481 			DRM_ERROR("Failed to update EDID property: %d\n", err);
482 			goto unlock;
483 		}
484 	}
485 
486 	num_modes += drm_add_edid_modes(connector, anx6345->edid);
487 
488 	/* Driver currently supports only 6bpc */
489 	connector->display_info.bpc = 6;
490 
491 unlock:
492 	if (power_off)
493 		anx6345_poweroff(anx6345);
494 
495 	mutex_unlock(&anx6345->lock);
496 
497 	if (!num_modes && anx6345->panel)
498 		num_modes += drm_panel_get_modes(anx6345->panel, connector);
499 
500 	return num_modes;
501 }
502 
503 static const struct drm_connector_helper_funcs anx6345_connector_helper_funcs = {
504 	.get_modes = anx6345_get_modes,
505 };
506 
507 static void
508 anx6345_connector_destroy(struct drm_connector *connector)
509 {
510 	drm_connector_cleanup(connector);
511 }
512 
513 static const struct drm_connector_funcs anx6345_connector_funcs = {
514 	.fill_modes = drm_helper_probe_single_connector_modes,
515 	.destroy = anx6345_connector_destroy,
516 	.reset = drm_atomic_helper_connector_reset,
517 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
518 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
519 };
520 
521 static int anx6345_bridge_attach(struct drm_bridge *bridge,
522 				 enum drm_bridge_attach_flags flags)
523 {
524 	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
525 	int err;
526 
527 	if (flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR) {
528 		DRM_ERROR("Fix bridge driver to make connector optional!");
529 		return -EINVAL;
530 	}
531 
532 	if (!bridge->encoder) {
533 		DRM_ERROR("Parent encoder object not found");
534 		return -ENODEV;
535 	}
536 
537 	/* Register aux channel */
538 	anx6345->aux.name = "DP-AUX";
539 	anx6345->aux.dev = &anx6345->client->dev;
540 	anx6345->aux.drm_dev = bridge->dev;
541 	anx6345->aux.transfer = anx6345_aux_transfer;
542 
543 	err = drm_dp_aux_register(&anx6345->aux);
544 	if (err < 0) {
545 		DRM_ERROR("Failed to register aux channel: %d\n", err);
546 		return err;
547 	}
548 
549 	err = drm_connector_init(bridge->dev, &anx6345->connector,
550 				 &anx6345_connector_funcs,
551 				 DRM_MODE_CONNECTOR_eDP);
552 	if (err) {
553 		DRM_ERROR("Failed to initialize connector: %d\n", err);
554 		goto aux_unregister;
555 	}
556 
557 	drm_connector_helper_add(&anx6345->connector,
558 				 &anx6345_connector_helper_funcs);
559 
560 	anx6345->connector.polled = DRM_CONNECTOR_POLL_HPD;
561 
562 	err = drm_connector_attach_encoder(&anx6345->connector,
563 					   bridge->encoder);
564 	if (err) {
565 		DRM_ERROR("Failed to link up connector to encoder: %d\n", err);
566 		goto connector_cleanup;
567 	}
568 
569 	err = drm_connector_register(&anx6345->connector);
570 	if (err) {
571 		DRM_ERROR("Failed to register connector: %d\n", err);
572 		goto connector_cleanup;
573 	}
574 
575 	return 0;
576 connector_cleanup:
577 	drm_connector_cleanup(&anx6345->connector);
578 aux_unregister:
579 	drm_dp_aux_unregister(&anx6345->aux);
580 	return err;
581 }
582 
583 static void anx6345_bridge_detach(struct drm_bridge *bridge)
584 {
585 	drm_dp_aux_unregister(&bridge_to_anx6345(bridge)->aux);
586 }
587 
588 static enum drm_mode_status
589 anx6345_bridge_mode_valid(struct drm_bridge *bridge,
590 			  const struct drm_display_info *info,
591 			  const struct drm_display_mode *mode)
592 {
593 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
594 		return MODE_NO_INTERLACE;
595 
596 	/* Max 1200p at 5.4 Ghz, one lane */
597 	if (mode->clock > 154000)
598 		return MODE_CLOCK_HIGH;
599 
600 	return MODE_OK;
601 }
602 
603 static void anx6345_bridge_disable(struct drm_bridge *bridge)
604 {
605 	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
606 
607 	/* Power off all modules except configuration registers access */
608 	anx6345_set_bits(anx6345->map[I2C_IDX_TXCOM], SP_POWERDOWN_CTRL_REG,
609 			 SP_HDCP_PD | SP_AUDIO_PD | SP_VIDEO_PD | SP_LINK_PD);
610 	if (anx6345->panel)
611 		drm_panel_disable(anx6345->panel);
612 
613 	if (anx6345->powered)
614 		anx6345_poweroff(anx6345);
615 }
616 
617 static void anx6345_bridge_enable(struct drm_bridge *bridge)
618 {
619 	struct anx6345 *anx6345 = bridge_to_anx6345(bridge);
620 	int err;
621 
622 	if (anx6345->panel)
623 		drm_panel_enable(anx6345->panel);
624 
625 	err = anx6345_start(anx6345);
626 	if (err) {
627 		DRM_ERROR("Failed to initialize: %d\n", err);
628 		return;
629 	}
630 
631 	err = anx6345_config_dp_output(anx6345);
632 	if (err)
633 		DRM_ERROR("Failed to enable DP output: %d\n", err);
634 }
635 
636 static const struct drm_bridge_funcs anx6345_bridge_funcs = {
637 	.attach = anx6345_bridge_attach,
638 	.detach = anx6345_bridge_detach,
639 	.mode_valid = anx6345_bridge_mode_valid,
640 	.disable = anx6345_bridge_disable,
641 	.enable = anx6345_bridge_enable,
642 };
643 
644 static void unregister_i2c_dummy_clients(struct anx6345 *anx6345)
645 {
646 	unsigned int i;
647 
648 	for (i = 1; i < ARRAY_SIZE(anx6345->i2c_clients); i++)
649 		if (anx6345->i2c_clients[i] &&
650 		    anx6345->i2c_clients[i]->addr != anx6345->client->addr)
651 			i2c_unregister_device(anx6345->i2c_clients[i]);
652 }
653 
654 static const struct regmap_config anx6345_regmap_config = {
655 	.reg_bits = 8,
656 	.val_bits = 8,
657 	.max_register = 0xff,
658 	.cache_type = REGCACHE_NONE,
659 };
660 
661 static const u16 anx6345_chipid_list[] = {
662 	0x6345,
663 };
664 
665 static bool anx6345_get_chip_id(struct anx6345 *anx6345)
666 {
667 	unsigned int i, idl, idh, version;
668 
669 	if (regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDL_REG, &idl))
670 		return false;
671 
672 	if (regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_IDH_REG, &idh))
673 		return false;
674 
675 	anx6345->chipid = (u8)idl | ((u8)idh << 8);
676 
677 	if (regmap_read(anx6345->map[I2C_IDX_TXCOM], SP_DEVICE_VERSION_REG,
678 			&version))
679 		return false;
680 
681 	for (i = 0; i < ARRAY_SIZE(anx6345_chipid_list); i++) {
682 		if (anx6345->chipid == anx6345_chipid_list[i]) {
683 			DRM_INFO("Found ANX%x (ver. %d) eDP Transmitter\n",
684 				 anx6345->chipid, version);
685 			return true;
686 		}
687 	}
688 
689 	DRM_ERROR("ANX%x (ver. %d) not supported by this driver\n",
690 		  anx6345->chipid, version);
691 
692 	return false;
693 }
694 
695 static int anx6345_i2c_probe(struct i2c_client *client,
696 			     const struct i2c_device_id *id)
697 {
698 	struct anx6345 *anx6345;
699 	struct device *dev;
700 	int i, err;
701 
702 	anx6345 = devm_kzalloc(&client->dev, sizeof(*anx6345), GFP_KERNEL);
703 	if (!anx6345)
704 		return -ENOMEM;
705 
706 	mutex_init(&anx6345->lock);
707 
708 	anx6345->bridge.of_node = client->dev.of_node;
709 
710 	anx6345->client = client;
711 	i2c_set_clientdata(client, anx6345);
712 
713 	dev = &anx6345->client->dev;
714 
715 	err = drm_of_find_panel_or_bridge(client->dev.of_node, 1, 0,
716 					  &anx6345->panel, NULL);
717 	if (err == -EPROBE_DEFER)
718 		return err;
719 
720 	if (err)
721 		DRM_DEBUG("No panel found\n");
722 
723 	/* 1.2V digital core power regulator  */
724 	anx6345->dvdd12 = devm_regulator_get(dev, "dvdd12");
725 	if (IS_ERR(anx6345->dvdd12)) {
726 		if (PTR_ERR(anx6345->dvdd12) != -EPROBE_DEFER)
727 			DRM_ERROR("Failed to get dvdd12 supply (%ld)\n",
728 				  PTR_ERR(anx6345->dvdd12));
729 		return PTR_ERR(anx6345->dvdd12);
730 	}
731 
732 	/* 2.5V digital core power regulator  */
733 	anx6345->dvdd25 = devm_regulator_get(dev, "dvdd25");
734 	if (IS_ERR(anx6345->dvdd25)) {
735 		if (PTR_ERR(anx6345->dvdd25) != -EPROBE_DEFER)
736 			DRM_ERROR("Failed to get dvdd25 supply (%ld)\n",
737 				  PTR_ERR(anx6345->dvdd25));
738 		return PTR_ERR(anx6345->dvdd25);
739 	}
740 
741 	/* GPIO for chip reset */
742 	anx6345->gpiod_reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
743 	if (IS_ERR(anx6345->gpiod_reset)) {
744 		DRM_ERROR("Reset gpio not found\n");
745 		return PTR_ERR(anx6345->gpiod_reset);
746 	}
747 
748 	/* Map slave addresses of ANX6345 */
749 	for (i = 0; i < I2C_NUM_ADDRESSES; i++) {
750 		if (anx6345_i2c_addresses[i] >> 1 != client->addr)
751 			anx6345->i2c_clients[i] = i2c_new_dummy_device(client->adapter,
752 						anx6345_i2c_addresses[i] >> 1);
753 		else
754 			anx6345->i2c_clients[i] = client;
755 
756 		if (IS_ERR(anx6345->i2c_clients[i])) {
757 			err = PTR_ERR(anx6345->i2c_clients[i]);
758 			DRM_ERROR("Failed to reserve I2C bus %02x\n",
759 				  anx6345_i2c_addresses[i]);
760 			goto err_unregister_i2c;
761 		}
762 
763 		anx6345->map[i] = devm_regmap_init_i2c(anx6345->i2c_clients[i],
764 						       &anx6345_regmap_config);
765 		if (IS_ERR(anx6345->map[i])) {
766 			err = PTR_ERR(anx6345->map[i]);
767 			DRM_ERROR("Failed regmap initialization %02x\n",
768 				  anx6345_i2c_addresses[i]);
769 			goto err_unregister_i2c;
770 		}
771 	}
772 
773 	/* Look for supported chip ID */
774 	anx6345_poweron(anx6345);
775 	if (anx6345_get_chip_id(anx6345)) {
776 		anx6345->bridge.funcs = &anx6345_bridge_funcs;
777 		drm_bridge_add(&anx6345->bridge);
778 
779 		return 0;
780 	} else {
781 		anx6345_poweroff(anx6345);
782 		err = -ENODEV;
783 	}
784 
785 err_unregister_i2c:
786 	unregister_i2c_dummy_clients(anx6345);
787 	return err;
788 }
789 
790 static int anx6345_i2c_remove(struct i2c_client *client)
791 {
792 	struct anx6345 *anx6345 = i2c_get_clientdata(client);
793 
794 	drm_bridge_remove(&anx6345->bridge);
795 
796 	unregister_i2c_dummy_clients(anx6345);
797 
798 	kfree(anx6345->edid);
799 
800 	mutex_destroy(&anx6345->lock);
801 
802 	return 0;
803 }
804 
805 static const struct i2c_device_id anx6345_id[] = {
806 	{ "anx6345", 0 },
807 	{ /* sentinel */ }
808 };
809 MODULE_DEVICE_TABLE(i2c, anx6345_id);
810 
811 static const struct of_device_id anx6345_match_table[] = {
812 	{ .compatible = "analogix,anx6345", },
813 	{ /* sentinel */ },
814 };
815 MODULE_DEVICE_TABLE(of, anx6345_match_table);
816 
817 static struct i2c_driver anx6345_driver = {
818 	.driver = {
819 		   .name = "anx6345",
820 		   .of_match_table = of_match_ptr(anx6345_match_table),
821 		  },
822 	.probe = anx6345_i2c_probe,
823 	.remove = anx6345_i2c_remove,
824 	.id_table = anx6345_id,
825 };
826 module_i2c_driver(anx6345_driver);
827 
828 MODULE_DESCRIPTION("ANX6345 eDP Transmitter driver");
829 MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
830 MODULE_LICENSE("GPL v2");
831