xref: /linux/drivers/gpu/drm/bridge/lontium-lt8912b.c (revision 3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, The Linux Foundation. All rights reserved.
4  */
5 
6 #include <linux/device.h>
7 #include <linux/delay.h>
8 #include <linux/gpio/consumer.h>
9 #include <linux/i2c.h>
10 #include <linux/media-bus-format.h>
11 #include <linux/regmap.h>
12 
13 #include <drm/drm_probe_helper.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_edid.h>
16 #include <drm/drm_mipi_dsi.h>
17 #include <drm/drm_of.h>
18 
19 #include <video/videomode.h>
20 
21 #define I2C_MAIN 0
22 #define I2C_ADDR_MAIN 0x48
23 
24 #define I2C_CEC_DSI 1
25 #define I2C_ADDR_CEC_DSI 0x49
26 
27 #define I2C_MAX_IDX 2
28 
29 struct lt8912 {
30 	struct device *dev;
31 	struct drm_bridge bridge;
32 	struct drm_connector connector;
33 
34 	struct i2c_client *i2c_client[I2C_MAX_IDX];
35 	struct regmap *regmap[I2C_MAX_IDX];
36 
37 	struct device_node *host_node;
38 
39 	struct mipi_dsi_device *dsi;
40 
41 	struct gpio_desc *gp_reset;
42 
43 	struct videomode mode;
44 
45 	struct regulator_bulk_data supplies[7];
46 
47 	u8 data_lanes;
48 	bool is_power_on;
49 };
50 
51 static int lt8912_write_init_config(struct lt8912 *lt)
52 {
53 	const struct reg_sequence seq[] = {
54 		/* Digital clock en*/
55 		{0x08, 0xff},
56 		{0x09, 0xff},
57 		{0x0a, 0xff},
58 		{0x0b, 0x7c},
59 		{0x0c, 0xff},
60 		{0x42, 0x04},
61 
62 		/*Tx Analog*/
63 		{0x31, 0xb1},
64 		{0x32, 0xb1},
65 		{0x33, 0x0e},
66 		{0x37, 0x00},
67 		{0x38, 0x22},
68 		{0x60, 0x82},
69 
70 		/*Cbus Analog*/
71 		{0x39, 0x45},
72 		{0x3a, 0x00},
73 		{0x3b, 0x00},
74 
75 		/*HDMI Pll Analog*/
76 		{0x44, 0x31},
77 		{0x55, 0x44},
78 		{0x57, 0x01},
79 		{0x5a, 0x02},
80 
81 		/*MIPI Analog*/
82 		{0x3e, 0xd6},
83 		{0x3f, 0xd4},
84 		{0x41, 0x3c},
85 		{0xB2, 0x00},
86 	};
87 
88 	return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
89 }
90 
91 static int lt8912_write_mipi_basic_config(struct lt8912 *lt)
92 {
93 	const struct reg_sequence seq[] = {
94 		{0x12, 0x04},
95 		{0x14, 0x00},
96 		{0x15, 0x00},
97 		{0x1a, 0x03},
98 		{0x1b, 0x03},
99 	};
100 
101 	return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
102 };
103 
104 static int lt8912_write_dds_config(struct lt8912 *lt)
105 {
106 	const struct reg_sequence seq[] = {
107 		{0x4e, 0xff},
108 		{0x4f, 0x56},
109 		{0x50, 0x69},
110 		{0x51, 0x80},
111 		{0x1f, 0x5e},
112 		{0x20, 0x01},
113 		{0x21, 0x2c},
114 		{0x22, 0x01},
115 		{0x23, 0xfa},
116 		{0x24, 0x00},
117 		{0x25, 0xc8},
118 		{0x26, 0x00},
119 		{0x27, 0x5e},
120 		{0x28, 0x01},
121 		{0x29, 0x2c},
122 		{0x2a, 0x01},
123 		{0x2b, 0xfa},
124 		{0x2c, 0x00},
125 		{0x2d, 0xc8},
126 		{0x2e, 0x00},
127 		{0x42, 0x64},
128 		{0x43, 0x00},
129 		{0x44, 0x04},
130 		{0x45, 0x00},
131 		{0x46, 0x59},
132 		{0x47, 0x00},
133 		{0x48, 0xf2},
134 		{0x49, 0x06},
135 		{0x4a, 0x00},
136 		{0x4b, 0x72},
137 		{0x4c, 0x45},
138 		{0x4d, 0x00},
139 		{0x52, 0x08},
140 		{0x53, 0x00},
141 		{0x54, 0xb2},
142 		{0x55, 0x00},
143 		{0x56, 0xe4},
144 		{0x57, 0x0d},
145 		{0x58, 0x00},
146 		{0x59, 0xe4},
147 		{0x5a, 0x8a},
148 		{0x5b, 0x00},
149 		{0x5c, 0x34},
150 		{0x1e, 0x4f},
151 		{0x51, 0x00},
152 	};
153 
154 	return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
155 }
156 
157 static int lt8912_write_rxlogicres_config(struct lt8912 *lt)
158 {
159 	int ret;
160 
161 	ret = regmap_write(lt->regmap[I2C_MAIN], 0x03, 0x7f);
162 	usleep_range(10000, 20000);
163 	ret |= regmap_write(lt->regmap[I2C_MAIN], 0x03, 0xff);
164 
165 	return ret;
166 };
167 
168 /* enable LVDS output with some hardcoded configuration, not required for the HDMI output */
169 static int lt8912_write_lvds_config(struct lt8912 *lt)
170 {
171 	const struct reg_sequence seq[] = {
172 		// lvds power up
173 		{0x44, 0x30},
174 		{0x51, 0x05},
175 
176 		// core pll bypass
177 		{0x50, 0x24}, // cp=50uA
178 		{0x51, 0x2d}, // Pix_clk as reference, second order passive LPF PLL
179 		{0x52, 0x04}, // loopdiv=0, use second-order PLL
180 		{0x69, 0x0e}, // CP_PRESET_DIV_RATIO
181 		{0x69, 0x8e},
182 		{0x6a, 0x00},
183 		{0x6c, 0xb8}, // RGD_CP_SOFT_K_EN,RGD_CP_SOFT_K[13:8]
184 		{0x6b, 0x51},
185 
186 		{0x04, 0xfb}, // core pll reset
187 		{0x04, 0xff},
188 
189 		// scaler bypass
190 		{0x7f, 0x00}, // disable scaler
191 		{0xa8, 0x13}, // 0x13: JEIDA, 0x33: VESA
192 
193 		{0x02, 0xf7}, // lvds pll reset
194 		{0x02, 0xff},
195 		{0x03, 0xcf},
196 		{0x03, 0xff},
197 	};
198 
199 	return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
200 };
201 
202 static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
203 {
204 	return container_of(b, struct lt8912, bridge);
205 }
206 
207 static inline struct lt8912 *connector_to_lt8912(struct drm_connector *c)
208 {
209 	return container_of(c, struct lt8912, connector);
210 }
211 
212 static const struct regmap_config lt8912_regmap_config = {
213 	.reg_bits = 8,
214 	.val_bits = 8,
215 	.max_register = 0xff,
216 };
217 
218 static int lt8912_init_i2c(struct lt8912 *lt, struct i2c_client *client)
219 {
220 	unsigned int i;
221 	/*
222 	 * At this time we only initialize 2 chips, but the lt8912 provides
223 	 * a third interface for the audio over HDMI configuration.
224 	 */
225 	struct i2c_board_info info[] = {
226 		{ I2C_BOARD_INFO("lt8912p0", I2C_ADDR_MAIN), },
227 		{ I2C_BOARD_INFO("lt8912p1", I2C_ADDR_CEC_DSI), },
228 	};
229 
230 	if (!lt)
231 		return -ENODEV;
232 
233 	for (i = 0; i < ARRAY_SIZE(info); i++) {
234 		if (i > 0) {
235 			lt->i2c_client[i] = i2c_new_dummy_device(client->adapter,
236 								 info[i].addr);
237 			if (IS_ERR(lt->i2c_client[i]))
238 				return PTR_ERR(lt->i2c_client[i]);
239 		}
240 
241 		lt->regmap[i] = devm_regmap_init_i2c(lt->i2c_client[i],
242 						     &lt8912_regmap_config);
243 		if (IS_ERR(lt->regmap[i]))
244 			return PTR_ERR(lt->regmap[i]);
245 	}
246 	return 0;
247 }
248 
249 static int lt8912_free_i2c(struct lt8912 *lt)
250 {
251 	unsigned int i;
252 
253 	for (i = 1; i < I2C_MAX_IDX; i++)
254 		i2c_unregister_device(lt->i2c_client[i]);
255 
256 	return 0;
257 }
258 
259 static int lt8912_hard_power_on(struct lt8912 *lt)
260 {
261 	int ret;
262 
263 	ret = regulator_bulk_enable(ARRAY_SIZE(lt->supplies), lt->supplies);
264 	if (ret)
265 		return ret;
266 
267 	gpiod_set_value_cansleep(lt->gp_reset, 0);
268 	msleep(20);
269 
270 	return 0;
271 }
272 
273 static void lt8912_hard_power_off(struct lt8912 *lt)
274 {
275 	gpiod_set_value_cansleep(lt->gp_reset, 1);
276 	msleep(20);
277 
278 	regulator_bulk_disable(ARRAY_SIZE(lt->supplies), lt->supplies);
279 
280 	lt->is_power_on = false;
281 }
282 
283 static int lt8912_video_setup(struct lt8912 *lt)
284 {
285 	u32 hactive, h_total, hpw, hfp, hbp;
286 	u32 vactive, v_total, vpw, vfp, vbp;
287 	u8 settle = 0x08;
288 	int ret, hsync_activehigh, vsync_activehigh;
289 
290 	if (!lt)
291 		return -EINVAL;
292 
293 	hactive = lt->mode.hactive;
294 	hfp = lt->mode.hfront_porch;
295 	hpw = lt->mode.hsync_len;
296 	hbp = lt->mode.hback_porch;
297 	h_total = hactive + hfp + hpw + hbp;
298 	hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH;
299 
300 	vactive = lt->mode.vactive;
301 	vfp = lt->mode.vfront_porch;
302 	vpw = lt->mode.vsync_len;
303 	vbp = lt->mode.vback_porch;
304 	v_total = vactive + vfp + vpw + vbp;
305 	vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH;
306 
307 	if (vactive <= 600)
308 		settle = 0x04;
309 	else if (vactive == 1080)
310 		settle = 0x0a;
311 
312 	ret = regmap_write(lt->regmap[I2C_CEC_DSI], 0x10, 0x01);
313 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x11, settle);
314 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x18, hpw);
315 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x19, vpw);
316 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1c, hactive & 0xff);
317 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1d, hactive >> 8);
318 
319 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x2f, 0x0c);
320 
321 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x34, h_total & 0xff);
322 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x35, h_total >> 8);
323 
324 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x36, v_total & 0xff);
325 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x37, v_total >> 8);
326 
327 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x38, vbp & 0xff);
328 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x39, vbp >> 8);
329 
330 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3a, vfp & 0xff);
331 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3b, vfp >> 8);
332 
333 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3c, hbp & 0xff);
334 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3d, hbp >> 8);
335 
336 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff);
337 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8);
338 
339 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0),
340 				  vsync_activehigh ? BIT(0) : 0);
341 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1),
342 				  hsync_activehigh ? BIT(1) : 0);
343 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0),
344 				  lt->connector.display_info.is_hdmi ? BIT(0) : 0);
345 
346 	return ret;
347 }
348 
349 static int lt8912_soft_power_on(struct lt8912 *lt)
350 {
351 	if (!lt->is_power_on) {
352 		u32 lanes = lt->data_lanes;
353 
354 		lt8912_write_init_config(lt);
355 		regmap_write(lt->regmap[I2C_CEC_DSI], 0x13, lanes & 3);
356 
357 		lt8912_write_mipi_basic_config(lt);
358 
359 		lt->is_power_on = true;
360 	}
361 
362 	return 0;
363 }
364 
365 static int lt8912_video_on(struct lt8912 *lt)
366 {
367 	int ret;
368 
369 	ret = lt8912_video_setup(lt);
370 	if (ret < 0)
371 		goto end;
372 
373 	ret = lt8912_write_dds_config(lt);
374 	if (ret < 0)
375 		goto end;
376 
377 	ret = lt8912_write_rxlogicres_config(lt);
378 	if (ret < 0)
379 		goto end;
380 
381 	ret = lt8912_write_lvds_config(lt);
382 	if (ret < 0)
383 		goto end;
384 
385 end:
386 	return ret;
387 }
388 
389 static enum drm_connector_status lt8912_check_cable_status(struct lt8912 *lt)
390 {
391 	int ret;
392 	unsigned int reg_val;
393 
394 	ret = regmap_read(lt->regmap[I2C_MAIN], 0xC1, &reg_val);
395 	if (ret)
396 		return connector_status_unknown;
397 
398 	if (reg_val & BIT(7))
399 		return connector_status_connected;
400 
401 	return connector_status_disconnected;
402 }
403 
404 static enum drm_connector_status
405 lt8912_connector_detect(struct drm_connector *connector, bool force)
406 {
407 	struct lt8912 *lt = connector_to_lt8912(connector);
408 
409 	if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_DETECT)
410 		return drm_bridge_detect(lt->bridge.next_bridge, connector);
411 
412 	return lt8912_check_cable_status(lt);
413 }
414 
415 static const struct drm_connector_funcs lt8912_connector_funcs = {
416 	.detect = lt8912_connector_detect,
417 	.fill_modes = drm_helper_probe_single_connector_modes,
418 	.destroy = drm_connector_cleanup,
419 	.reset = drm_atomic_helper_connector_reset,
420 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
421 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
422 };
423 
424 static int lt8912_connector_get_modes(struct drm_connector *connector)
425 {
426 	const struct drm_edid *drm_edid;
427 	struct lt8912 *lt = connector_to_lt8912(connector);
428 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
429 	int ret, num;
430 
431 	drm_edid = drm_bridge_edid_read(lt->bridge.next_bridge, connector);
432 	drm_edid_connector_update(connector, drm_edid);
433 	if (!drm_edid)
434 		return 0;
435 
436 	num = drm_edid_connector_add_modes(connector);
437 
438 	ret = drm_display_info_set_bus_formats(&connector->display_info,
439 					       &bus_format, 1);
440 	if (ret < 0)
441 		num = 0;
442 
443 	drm_edid_free(drm_edid);
444 	return num;
445 }
446 
447 static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
448 	.get_modes = lt8912_connector_get_modes,
449 };
450 
451 static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
452 				   const struct drm_display_mode *mode,
453 				   const struct drm_display_mode *adj)
454 {
455 	struct lt8912 *lt = bridge_to_lt8912(bridge);
456 
457 	drm_display_mode_to_videomode(adj, &lt->mode);
458 }
459 
460 static void lt8912_bridge_enable(struct drm_bridge *bridge,
461 				 struct drm_atomic_commit *commit)
462 {
463 	struct lt8912 *lt = bridge_to_lt8912(bridge);
464 
465 	lt8912_video_on(lt);
466 }
467 
468 static int lt8912_attach_dsi(struct lt8912 *lt)
469 {
470 	struct device *dev = lt->dev;
471 	struct mipi_dsi_host *host;
472 	struct mipi_dsi_device *dsi;
473 	int ret = -1;
474 	const struct mipi_dsi_device_info info = { .type = "lt8912",
475 						   .channel = 0,
476 						   .node = NULL,
477 						 };
478 
479 	host = of_find_mipi_dsi_host_by_node(lt->host_node);
480 	if (!host)
481 		return dev_err_probe(dev, -EPROBE_DEFER, "failed to find dsi host\n");
482 
483 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
484 	if (IS_ERR(dsi)) {
485 		ret = PTR_ERR(dsi);
486 		dev_err(dev, "failed to create dsi device (%d)\n", ret);
487 		return ret;
488 	}
489 
490 	lt->dsi = dsi;
491 
492 	dsi->lanes = lt->data_lanes;
493 	dsi->format = MIPI_DSI_FMT_RGB888;
494 
495 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
496 			  MIPI_DSI_MODE_LPM |
497 			  MIPI_DSI_MODE_VIDEO_NO_HFP |
498 			  MIPI_DSI_MODE_NO_EOT_PACKET;
499 
500 	ret = devm_mipi_dsi_attach(dev, dsi);
501 	if (ret < 0) {
502 		dev_err(dev, "failed to attach dsi to host\n");
503 		return ret;
504 	}
505 
506 	return 0;
507 }
508 
509 static void lt8912_bridge_hpd_cb(void *data, enum drm_connector_status status)
510 {
511 	struct lt8912 *lt = data;
512 
513 	if (lt->bridge.dev)
514 		drm_helper_hpd_irq_event(lt->bridge.dev);
515 }
516 
517 static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
518 {
519 	int ret;
520 	struct lt8912 *lt = bridge_to_lt8912(bridge);
521 	struct drm_connector *connector = &lt->connector;
522 
523 	if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD) {
524 		drm_bridge_hpd_enable(lt->bridge.next_bridge, lt8912_bridge_hpd_cb, lt);
525 		connector->polled = DRM_CONNECTOR_POLL_HPD;
526 	} else {
527 		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
528 				    DRM_CONNECTOR_POLL_DISCONNECT;
529 	}
530 
531 	ret = drm_connector_init(bridge->dev, connector,
532 				 &lt8912_connector_funcs,
533 				 lt->bridge.next_bridge->type);
534 	if (ret)
535 		goto exit;
536 
537 	drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);
538 
539 	connector->dpms = DRM_MODE_DPMS_OFF;
540 	drm_connector_attach_encoder(connector, bridge->encoder);
541 
542 exit:
543 	return ret;
544 }
545 
546 static int lt8912_bridge_attach(struct drm_bridge *bridge,
547 				struct drm_encoder *encoder,
548 				enum drm_bridge_attach_flags flags)
549 {
550 	struct lt8912 *lt = bridge_to_lt8912(bridge);
551 	int ret;
552 
553 	ret = drm_bridge_attach(encoder, lt->bridge.next_bridge, bridge,
554 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
555 	if (ret < 0) {
556 		dev_err(lt->dev, "Failed to attach next bridge (%d)\n", ret);
557 		return ret;
558 	}
559 
560 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
561 		ret = lt8912_bridge_connector_init(bridge);
562 		if (ret) {
563 			dev_err(lt->dev, "Failed to init bridge ! (%d)\n", ret);
564 			return ret;
565 		}
566 	}
567 
568 	ret = lt8912_hard_power_on(lt);
569 	if (ret)
570 		return ret;
571 
572 	ret = lt8912_soft_power_on(lt);
573 	if (ret)
574 		goto error;
575 
576 	return 0;
577 
578 error:
579 	lt8912_hard_power_off(lt);
580 	return ret;
581 }
582 
583 static void lt8912_bridge_detach(struct drm_bridge *bridge)
584 {
585 	struct lt8912 *lt = bridge_to_lt8912(bridge);
586 
587 	lt8912_hard_power_off(lt);
588 
589 	if (lt->connector.dev && lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_HPD)
590 		drm_bridge_hpd_disable(lt->bridge.next_bridge);
591 }
592 
593 static enum drm_mode_status
594 lt8912_bridge_mode_valid(struct drm_bridge *bridge,
595 			 const struct drm_display_info *info,
596 			 const struct drm_display_mode *mode)
597 {
598 	if (mode->clock > 150000)
599 		return MODE_CLOCK_HIGH;
600 
601 	if (mode->hdisplay > 1920)
602 		return MODE_BAD_HVALUE;
603 
604 	if (mode->vdisplay > 1080)
605 		return MODE_BAD_VVALUE;
606 
607 	return MODE_OK;
608 }
609 
610 static enum drm_connector_status
611 lt8912_bridge_detect(struct drm_bridge *bridge, struct drm_connector *connector)
612 {
613 	struct lt8912 *lt = bridge_to_lt8912(bridge);
614 
615 	if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_DETECT)
616 		return drm_bridge_detect(lt->bridge.next_bridge, connector);
617 
618 	return lt8912_check_cable_status(lt);
619 }
620 
621 static const struct drm_edid *lt8912_bridge_edid_read(struct drm_bridge *bridge,
622 						      struct drm_connector *connector)
623 {
624 	struct lt8912 *lt = bridge_to_lt8912(bridge);
625 
626 	/*
627 	 * edid must be read through the ddc bus but it must be
628 	 * given to the hdmi connector node.
629 	 */
630 	if (lt->bridge.next_bridge->ops & DRM_BRIDGE_OP_EDID)
631 		return drm_bridge_edid_read(lt->bridge.next_bridge, connector);
632 
633 	dev_warn(lt->dev, "The connected bridge does not supports DRM_BRIDGE_OP_EDID\n");
634 	return NULL;
635 }
636 
637 static const struct drm_bridge_funcs lt8912_bridge_funcs = {
638 	.atomic_create_state = drm_atomic_helper_bridge_create_state,
639 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
640 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
641 	.attach = lt8912_bridge_attach,
642 	.detach = lt8912_bridge_detach,
643 	.mode_valid = lt8912_bridge_mode_valid,
644 	.mode_set = lt8912_bridge_mode_set,
645 	.atomic_enable = lt8912_bridge_enable,
646 	.detect = lt8912_bridge_detect,
647 	.edid_read = lt8912_bridge_edid_read,
648 };
649 
650 static int lt8912_bridge_resume(struct device *dev)
651 {
652 	struct lt8912 *lt = dev_get_drvdata(dev);
653 	int ret;
654 
655 	ret = lt8912_hard_power_on(lt);
656 	if (ret)
657 		return ret;
658 
659 	ret = lt8912_soft_power_on(lt);
660 	if (ret)
661 		return ret;
662 
663 	return lt8912_video_on(lt);
664 }
665 
666 static int lt8912_bridge_suspend(struct device *dev)
667 {
668 	struct lt8912 *lt = dev_get_drvdata(dev);
669 
670 	lt8912_hard_power_off(lt);
671 
672 	return 0;
673 }
674 
675 static DEFINE_SIMPLE_DEV_PM_OPS(lt8912_bridge_pm_ops, lt8912_bridge_suspend, lt8912_bridge_resume);
676 
677 static int lt8912_get_regulators(struct lt8912 *lt)
678 {
679 	unsigned int i;
680 	static const char * const supply_names[] = {
681 		"vdd", "vccmipirx", "vccsysclk", "vcclvdstx",
682 		"vcchdmitx", "vcclvdspll", "vcchdmipll"
683 	};
684 
685 	for (i = 0; i < ARRAY_SIZE(lt->supplies); i++)
686 		lt->supplies[i].supply = supply_names[i];
687 
688 	return devm_regulator_bulk_get(lt->dev, ARRAY_SIZE(lt->supplies),
689 				       lt->supplies);
690 }
691 
692 static int lt8912_parse_dt(struct lt8912 *lt)
693 {
694 	struct gpio_desc *gp_reset;
695 	struct device *dev = lt->dev;
696 	int ret;
697 	int data_lanes;
698 	struct device_node *port_node;
699 
700 	gp_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
701 	if (IS_ERR(gp_reset)) {
702 		ret = PTR_ERR(gp_reset);
703 		if (ret != -EPROBE_DEFER)
704 			dev_err(dev, "Failed to get reset gpio: %d\n", ret);
705 		return ret;
706 	}
707 	lt->gp_reset = gp_reset;
708 
709 	data_lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, -1, 1, 4);
710 	if (data_lanes < 0) {
711 		dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
712 		return data_lanes;
713 	}
714 
715 	lt->data_lanes = data_lanes;
716 
717 	lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
718 	if (!lt->host_node) {
719 		dev_err(lt->dev, "%s: Failed to get remote port\n", __func__);
720 		return -ENODEV;
721 	}
722 
723 	port_node = of_graph_get_remote_node(dev->of_node, 1, -1);
724 	if (!port_node) {
725 		dev_err(lt->dev, "%s: Failed to get connector port\n", __func__);
726 		ret = -ENODEV;
727 		goto err_free_host_node;
728 	}
729 
730 	lt->bridge.next_bridge = of_drm_find_and_get_bridge(port_node);
731 	if (!lt->bridge.next_bridge) {
732 		ret = -EPROBE_DEFER;
733 		dev_err_probe(lt->dev, ret, "%s: Failed to get hdmi port\n", __func__);
734 		goto err_free_host_node;
735 	}
736 
737 	if (!of_device_is_compatible(port_node, "hdmi-connector")) {
738 		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
739 		ret = -EINVAL;
740 		goto err_free_host_node;
741 	}
742 
743 	ret = lt8912_get_regulators(lt);
744 	if (ret)
745 		goto err_free_host_node;
746 
747 	of_node_put(port_node);
748 	return 0;
749 
750 err_free_host_node:
751 	of_node_put(port_node);
752 	of_node_put(lt->host_node);
753 	return ret;
754 }
755 
756 static int lt8912_put_dt(struct lt8912 *lt)
757 {
758 	of_node_put(lt->host_node);
759 	return 0;
760 }
761 
762 static int lt8912_probe(struct i2c_client *client)
763 {
764 	static struct lt8912 *lt;
765 	int ret = 0;
766 	struct device *dev = &client->dev;
767 
768 	lt = devm_drm_bridge_alloc(dev, struct lt8912, bridge,
769 				   &lt8912_bridge_funcs);
770 	if (IS_ERR(lt))
771 		return PTR_ERR(lt);
772 
773 	lt->dev = dev;
774 	lt->i2c_client[0] = client;
775 
776 	ret = lt8912_parse_dt(lt);
777 	if (ret)
778 		goto err_dt_parse;
779 
780 	ret = lt8912_init_i2c(lt, client);
781 	if (ret)
782 		goto err_i2c;
783 
784 	i2c_set_clientdata(client, lt);
785 
786 	lt->bridge.of_node = dev->of_node;
787 	lt->bridge.ops = (DRM_BRIDGE_OP_EDID |
788 			  DRM_BRIDGE_OP_DETECT);
789 
790 	drm_bridge_add(&lt->bridge);
791 
792 	ret = lt8912_attach_dsi(lt);
793 	if (ret)
794 		goto err_attach;
795 
796 	return 0;
797 
798 err_attach:
799 	drm_bridge_remove(&lt->bridge);
800 	lt8912_free_i2c(lt);
801 err_i2c:
802 	lt8912_put_dt(lt);
803 err_dt_parse:
804 	return ret;
805 }
806 
807 static void lt8912_remove(struct i2c_client *client)
808 {
809 	struct lt8912 *lt = i2c_get_clientdata(client);
810 
811 	drm_bridge_remove(&lt->bridge);
812 	lt8912_free_i2c(lt);
813 	lt8912_put_dt(lt);
814 }
815 
816 static const struct of_device_id lt8912_dt_match[] = {
817 	{.compatible = "lontium,lt8912b"},
818 	{}
819 };
820 MODULE_DEVICE_TABLE(of, lt8912_dt_match);
821 
822 static const struct i2c_device_id lt8912_id[] = {
823 	{ .name = "lt8912" },
824 	{ }
825 };
826 MODULE_DEVICE_TABLE(i2c, lt8912_id);
827 
828 static struct i2c_driver lt8912_i2c_driver = {
829 	.driver = {
830 		.name = "lt8912",
831 		.of_match_table = lt8912_dt_match,
832 		.pm = pm_sleep_ptr(&lt8912_bridge_pm_ops),
833 	},
834 	.probe = lt8912_probe,
835 	.remove = lt8912_remove,
836 	.id_table = lt8912_id,
837 };
838 module_i2c_driver(lt8912_i2c_driver);
839 
840 MODULE_AUTHOR("Adrien Grassein <adrien.grassein@gmail.com>");
841 MODULE_DESCRIPTION("lt8912 drm driver");
842 MODULE_LICENSE("GPL v2");
843