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