xref: /linux/drivers/gpu/drm/bridge/lontium-lt8912b.c (revision b58b13f156c00c2457035b7071eaaac105fe6836)
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 	struct drm_bridge *hdmi_port;
39 
40 	struct mipi_dsi_device *dsi;
41 
42 	struct gpio_desc *gp_reset;
43 
44 	struct videomode mode;
45 
46 	struct regulator_bulk_data supplies[7];
47 
48 	u8 data_lanes;
49 	bool is_power_on;
50 };
51 
52 static int lt8912_write_init_config(struct lt8912 *lt)
53 {
54 	const struct reg_sequence seq[] = {
55 		/* Digital clock en*/
56 		{0x08, 0xff},
57 		{0x09, 0xff},
58 		{0x0a, 0xff},
59 		{0x0b, 0x7c},
60 		{0x0c, 0xff},
61 		{0x42, 0x04},
62 
63 		/*Tx Analog*/
64 		{0x31, 0xb1},
65 		{0x32, 0xb1},
66 		{0x33, 0x0e},
67 		{0x37, 0x00},
68 		{0x38, 0x22},
69 		{0x60, 0x82},
70 
71 		/*Cbus Analog*/
72 		{0x39, 0x45},
73 		{0x3a, 0x00},
74 		{0x3b, 0x00},
75 
76 		/*HDMI Pll Analog*/
77 		{0x44, 0x31},
78 		{0x55, 0x44},
79 		{0x57, 0x01},
80 		{0x5a, 0x02},
81 
82 		/*MIPI Analog*/
83 		{0x3e, 0xd6},
84 		{0x3f, 0xd4},
85 		{0x41, 0x3c},
86 		{0xB2, 0x00},
87 	};
88 
89 	return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
90 }
91 
92 static int lt8912_write_mipi_basic_config(struct lt8912 *lt)
93 {
94 	const struct reg_sequence seq[] = {
95 		{0x12, 0x04},
96 		{0x14, 0x00},
97 		{0x15, 0x00},
98 		{0x1a, 0x03},
99 		{0x1b, 0x03},
100 	};
101 
102 	return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
103 };
104 
105 static int lt8912_write_dds_config(struct lt8912 *lt)
106 {
107 	const struct reg_sequence seq[] = {
108 		{0x4e, 0xff},
109 		{0x4f, 0x56},
110 		{0x50, 0x69},
111 		{0x51, 0x80},
112 		{0x1f, 0x5e},
113 		{0x20, 0x01},
114 		{0x21, 0x2c},
115 		{0x22, 0x01},
116 		{0x23, 0xfa},
117 		{0x24, 0x00},
118 		{0x25, 0xc8},
119 		{0x26, 0x00},
120 		{0x27, 0x5e},
121 		{0x28, 0x01},
122 		{0x29, 0x2c},
123 		{0x2a, 0x01},
124 		{0x2b, 0xfa},
125 		{0x2c, 0x00},
126 		{0x2d, 0xc8},
127 		{0x2e, 0x00},
128 		{0x42, 0x64},
129 		{0x43, 0x00},
130 		{0x44, 0x04},
131 		{0x45, 0x00},
132 		{0x46, 0x59},
133 		{0x47, 0x00},
134 		{0x48, 0xf2},
135 		{0x49, 0x06},
136 		{0x4a, 0x00},
137 		{0x4b, 0x72},
138 		{0x4c, 0x45},
139 		{0x4d, 0x00},
140 		{0x52, 0x08},
141 		{0x53, 0x00},
142 		{0x54, 0xb2},
143 		{0x55, 0x00},
144 		{0x56, 0xe4},
145 		{0x57, 0x0d},
146 		{0x58, 0x00},
147 		{0x59, 0xe4},
148 		{0x5a, 0x8a},
149 		{0x5b, 0x00},
150 		{0x5c, 0x34},
151 		{0x1e, 0x4f},
152 		{0x51, 0x00},
153 	};
154 
155 	return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq));
156 }
157 
158 static int lt8912_write_rxlogicres_config(struct lt8912 *lt)
159 {
160 	int ret;
161 
162 	ret = regmap_write(lt->regmap[I2C_MAIN], 0x03, 0x7f);
163 	usleep_range(10000, 20000);
164 	ret |= regmap_write(lt->regmap[I2C_MAIN], 0x03, 0xff);
165 
166 	return ret;
167 };
168 
169 /* enable LVDS output with some hardcoded configuration, not required for the HDMI output */
170 static int lt8912_write_lvds_config(struct lt8912 *lt)
171 {
172 	const struct reg_sequence seq[] = {
173 		// lvds power up
174 		{0x44, 0x30},
175 		{0x51, 0x05},
176 
177 		// core pll bypass
178 		{0x50, 0x24}, // cp=50uA
179 		{0x51, 0x2d}, // Pix_clk as reference, second order passive LPF PLL
180 		{0x52, 0x04}, // loopdiv=0, use second-order PLL
181 		{0x69, 0x0e}, // CP_PRESET_DIV_RATIO
182 		{0x69, 0x8e},
183 		{0x6a, 0x00},
184 		{0x6c, 0xb8}, // RGD_CP_SOFT_K_EN,RGD_CP_SOFT_K[13:8]
185 		{0x6b, 0x51},
186 
187 		{0x04, 0xfb}, // core pll reset
188 		{0x04, 0xff},
189 
190 		// scaler bypass
191 		{0x7f, 0x00}, // disable scaler
192 		{0xa8, 0x13}, // 0x13: JEIDA, 0x33: VESA
193 
194 		{0x02, 0xf7}, // lvds pll reset
195 		{0x02, 0xff},
196 		{0x03, 0xcf},
197 		{0x03, 0xff},
198 	};
199 
200 	return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
201 };
202 
203 static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
204 {
205 	return container_of(b, struct lt8912, bridge);
206 }
207 
208 static inline struct lt8912 *connector_to_lt8912(struct drm_connector *c)
209 {
210 	return container_of(c, struct lt8912, connector);
211 }
212 
213 static const struct regmap_config lt8912_regmap_config = {
214 	.reg_bits = 8,
215 	.val_bits = 8,
216 	.max_register = 0xff,
217 };
218 
219 static int lt8912_init_i2c(struct lt8912 *lt, struct i2c_client *client)
220 {
221 	unsigned int i;
222 	/*
223 	 * At this time we only initialize 2 chips, but the lt8912 provides
224 	 * a third interface for the audio over HDMI configuration.
225 	 */
226 	struct i2c_board_info info[] = {
227 		{ I2C_BOARD_INFO("lt8912p0", I2C_ADDR_MAIN), },
228 		{ I2C_BOARD_INFO("lt8912p1", I2C_ADDR_CEC_DSI), },
229 	};
230 
231 	if (!lt)
232 		return -ENODEV;
233 
234 	for (i = 0; i < ARRAY_SIZE(info); i++) {
235 		if (i > 0) {
236 			lt->i2c_client[i] = i2c_new_dummy_device(client->adapter,
237 								 info[i].addr);
238 			if (IS_ERR(lt->i2c_client[i]))
239 				return PTR_ERR(lt->i2c_client[i]);
240 		}
241 
242 		lt->regmap[i] = devm_regmap_init_i2c(lt->i2c_client[i],
243 						     &lt8912_regmap_config);
244 		if (IS_ERR(lt->regmap[i]))
245 			return PTR_ERR(lt->regmap[i]);
246 	}
247 	return 0;
248 }
249 
250 static int lt8912_free_i2c(struct lt8912 *lt)
251 {
252 	unsigned int i;
253 
254 	for (i = 1; i < I2C_MAX_IDX; i++)
255 		i2c_unregister_device(lt->i2c_client[i]);
256 
257 	return 0;
258 }
259 
260 static int lt8912_hard_power_on(struct lt8912 *lt)
261 {
262 	int ret;
263 
264 	ret = regulator_bulk_enable(ARRAY_SIZE(lt->supplies), lt->supplies);
265 	if (ret)
266 		return ret;
267 
268 	gpiod_set_value_cansleep(lt->gp_reset, 0);
269 	msleep(20);
270 
271 	return 0;
272 }
273 
274 static void lt8912_hard_power_off(struct lt8912 *lt)
275 {
276 	gpiod_set_value_cansleep(lt->gp_reset, 1);
277 	msleep(20);
278 
279 	regulator_bulk_disable(ARRAY_SIZE(lt->supplies), lt->supplies);
280 
281 	lt->is_power_on = false;
282 }
283 
284 static int lt8912_video_setup(struct lt8912 *lt)
285 {
286 	u32 hactive, h_total, hpw, hfp, hbp;
287 	u32 vactive, v_total, vpw, vfp, vbp;
288 	u8 settle = 0x08;
289 	int ret, hsync_activehigh, vsync_activehigh;
290 
291 	if (!lt)
292 		return -EINVAL;
293 
294 	hactive = lt->mode.hactive;
295 	hfp = lt->mode.hfront_porch;
296 	hpw = lt->mode.hsync_len;
297 	hbp = lt->mode.hback_porch;
298 	h_total = hactive + hfp + hpw + hbp;
299 	hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH;
300 
301 	vactive = lt->mode.vactive;
302 	vfp = lt->mode.vfront_porch;
303 	vpw = lt->mode.vsync_len;
304 	vbp = lt->mode.vback_porch;
305 	v_total = vactive + vfp + vpw + vbp;
306 	vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH;
307 
308 	if (vactive <= 600)
309 		settle = 0x04;
310 	else if (vactive == 1080)
311 		settle = 0x0a;
312 
313 	ret = regmap_write(lt->regmap[I2C_CEC_DSI], 0x10, 0x01);
314 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x11, settle);
315 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x18, hpw);
316 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x19, vpw);
317 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1c, hactive & 0xff);
318 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1d, hactive >> 8);
319 
320 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x2f, 0x0c);
321 
322 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x34, h_total & 0xff);
323 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x35, h_total >> 8);
324 
325 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x36, v_total & 0xff);
326 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x37, v_total >> 8);
327 
328 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x38, vbp & 0xff);
329 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x39, vbp >> 8);
330 
331 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3a, vfp & 0xff);
332 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3b, vfp >> 8);
333 
334 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3c, hbp & 0xff);
335 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3d, hbp >> 8);
336 
337 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff);
338 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8);
339 
340 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0),
341 				  vsync_activehigh ? BIT(0) : 0);
342 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1),
343 				  hsync_activehigh ? BIT(1) : 0);
344 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0),
345 				  lt->connector.display_info.is_hdmi ? BIT(0) : 0);
346 
347 	return ret;
348 }
349 
350 static int lt8912_soft_power_on(struct lt8912 *lt)
351 {
352 	if (!lt->is_power_on) {
353 		u32 lanes = lt->data_lanes;
354 
355 		lt8912_write_init_config(lt);
356 		regmap_write(lt->regmap[I2C_CEC_DSI], 0x13, lanes & 3);
357 
358 		lt8912_write_mipi_basic_config(lt);
359 
360 		lt->is_power_on = true;
361 	}
362 
363 	return 0;
364 }
365 
366 static int lt8912_video_on(struct lt8912 *lt)
367 {
368 	int ret;
369 
370 	ret = lt8912_video_setup(lt);
371 	if (ret < 0)
372 		goto end;
373 
374 	ret = lt8912_write_dds_config(lt);
375 	if (ret < 0)
376 		goto end;
377 
378 	ret = lt8912_write_rxlogicres_config(lt);
379 	if (ret < 0)
380 		goto end;
381 
382 	ret = lt8912_write_lvds_config(lt);
383 	if (ret < 0)
384 		goto end;
385 
386 end:
387 	return ret;
388 }
389 
390 static enum drm_connector_status lt8912_check_cable_status(struct lt8912 *lt)
391 {
392 	int ret;
393 	unsigned int reg_val;
394 
395 	ret = regmap_read(lt->regmap[I2C_MAIN], 0xC1, &reg_val);
396 	if (ret)
397 		return connector_status_unknown;
398 
399 	if (reg_val & BIT(7))
400 		return connector_status_connected;
401 
402 	return connector_status_disconnected;
403 }
404 
405 static enum drm_connector_status
406 lt8912_connector_detect(struct drm_connector *connector, bool force)
407 {
408 	struct lt8912 *lt = connector_to_lt8912(connector);
409 
410 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
411 		return drm_bridge_detect(lt->hdmi_port);
412 
413 	return lt8912_check_cable_status(lt);
414 }
415 
416 static const struct drm_connector_funcs lt8912_connector_funcs = {
417 	.detect = lt8912_connector_detect,
418 	.fill_modes = drm_helper_probe_single_connector_modes,
419 	.destroy = drm_connector_cleanup,
420 	.reset = drm_atomic_helper_connector_reset,
421 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
422 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
423 };
424 
425 static enum drm_mode_status
426 lt8912_connector_mode_valid(struct drm_connector *connector,
427 			    struct drm_display_mode *mode)
428 {
429 	if (mode->clock > 150000)
430 		return MODE_CLOCK_HIGH;
431 
432 	if (mode->hdisplay > 1920)
433 		return MODE_BAD_HVALUE;
434 
435 	if (mode->vdisplay > 1080)
436 		return MODE_BAD_VVALUE;
437 
438 	return MODE_OK;
439 }
440 
441 static int lt8912_connector_get_modes(struct drm_connector *connector)
442 {
443 	struct edid *edid;
444 	int ret = -1;
445 	int num = 0;
446 	struct lt8912 *lt = connector_to_lt8912(connector);
447 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
448 
449 	edid = drm_bridge_get_edid(lt->hdmi_port, connector);
450 	if (edid) {
451 		drm_connector_update_edid_property(connector, edid);
452 		num = drm_add_edid_modes(connector, edid);
453 	} else {
454 		return ret;
455 	}
456 
457 	ret = drm_display_info_set_bus_formats(&connector->display_info,
458 					       &bus_format, 1);
459 	if (ret)
460 		num = ret;
461 
462 	kfree(edid);
463 	return num;
464 }
465 
466 static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
467 	.get_modes = lt8912_connector_get_modes,
468 	.mode_valid = lt8912_connector_mode_valid,
469 };
470 
471 static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
472 				   const struct drm_display_mode *mode,
473 				   const struct drm_display_mode *adj)
474 {
475 	struct lt8912 *lt = bridge_to_lt8912(bridge);
476 
477 	drm_display_mode_to_videomode(adj, &lt->mode);
478 }
479 
480 static void lt8912_bridge_enable(struct drm_bridge *bridge)
481 {
482 	struct lt8912 *lt = bridge_to_lt8912(bridge);
483 
484 	lt8912_video_on(lt);
485 }
486 
487 static int lt8912_attach_dsi(struct lt8912 *lt)
488 {
489 	struct device *dev = lt->dev;
490 	struct mipi_dsi_host *host;
491 	struct mipi_dsi_device *dsi;
492 	int ret = -1;
493 	const struct mipi_dsi_device_info info = { .type = "lt8912",
494 						   .channel = 0,
495 						   .node = NULL,
496 						 };
497 
498 	host = of_find_mipi_dsi_host_by_node(lt->host_node);
499 	if (!host) {
500 		dev_err(dev, "failed to find dsi host\n");
501 		return -EPROBE_DEFER;
502 	}
503 
504 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
505 	if (IS_ERR(dsi)) {
506 		ret = PTR_ERR(dsi);
507 		dev_err(dev, "failed to create dsi device (%d)\n", ret);
508 		return ret;
509 	}
510 
511 	lt->dsi = dsi;
512 
513 	dsi->lanes = lt->data_lanes;
514 	dsi->format = MIPI_DSI_FMT_RGB888;
515 
516 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
517 			  MIPI_DSI_MODE_LPM |
518 			  MIPI_DSI_MODE_NO_EOT_PACKET;
519 
520 	ret = devm_mipi_dsi_attach(dev, dsi);
521 	if (ret < 0) {
522 		dev_err(dev, "failed to attach dsi to host\n");
523 		return ret;
524 	}
525 
526 	return 0;
527 }
528 
529 static void lt8912_bridge_hpd_cb(void *data, enum drm_connector_status status)
530 {
531 	struct lt8912 *lt = data;
532 
533 	if (lt->bridge.dev)
534 		drm_helper_hpd_irq_event(lt->bridge.dev);
535 }
536 
537 static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
538 {
539 	int ret;
540 	struct lt8912 *lt = bridge_to_lt8912(bridge);
541 	struct drm_connector *connector = &lt->connector;
542 
543 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD) {
544 		drm_bridge_hpd_enable(lt->hdmi_port, lt8912_bridge_hpd_cb, lt);
545 		connector->polled = DRM_CONNECTOR_POLL_HPD;
546 	} else {
547 		connector->polled = DRM_CONNECTOR_POLL_CONNECT |
548 				    DRM_CONNECTOR_POLL_DISCONNECT;
549 	}
550 
551 	ret = drm_connector_init(bridge->dev, connector,
552 				 &lt8912_connector_funcs,
553 				 lt->hdmi_port->type);
554 	if (ret)
555 		goto exit;
556 
557 	drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);
558 
559 	connector->dpms = DRM_MODE_DPMS_OFF;
560 	drm_connector_attach_encoder(connector, bridge->encoder);
561 
562 exit:
563 	return ret;
564 }
565 
566 static int lt8912_bridge_attach(struct drm_bridge *bridge,
567 				enum drm_bridge_attach_flags flags)
568 {
569 	struct lt8912 *lt = bridge_to_lt8912(bridge);
570 	int ret;
571 
572 	ret = drm_bridge_attach(bridge->encoder, lt->hdmi_port, bridge,
573 				DRM_BRIDGE_ATTACH_NO_CONNECTOR);
574 	if (ret < 0) {
575 		dev_err(lt->dev, "Failed to attach next bridge (%d)\n", ret);
576 		return ret;
577 	}
578 
579 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
580 		ret = lt8912_bridge_connector_init(bridge);
581 		if (ret) {
582 			dev_err(lt->dev, "Failed to init bridge ! (%d)\n", ret);
583 			return ret;
584 		}
585 	}
586 
587 	ret = lt8912_hard_power_on(lt);
588 	if (ret)
589 		return ret;
590 
591 	ret = lt8912_soft_power_on(lt);
592 	if (ret)
593 		goto error;
594 
595 	return 0;
596 
597 error:
598 	lt8912_hard_power_off(lt);
599 	return ret;
600 }
601 
602 static void lt8912_bridge_detach(struct drm_bridge *bridge)
603 {
604 	struct lt8912 *lt = bridge_to_lt8912(bridge);
605 
606 	lt8912_hard_power_off(lt);
607 
608 	if (lt->connector.dev && lt->hdmi_port->ops & DRM_BRIDGE_OP_HPD)
609 		drm_bridge_hpd_disable(lt->hdmi_port);
610 }
611 
612 static enum drm_connector_status
613 lt8912_bridge_detect(struct drm_bridge *bridge)
614 {
615 	struct lt8912 *lt = bridge_to_lt8912(bridge);
616 
617 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
618 		return drm_bridge_detect(lt->hdmi_port);
619 
620 	return lt8912_check_cable_status(lt);
621 }
622 
623 static struct edid *lt8912_bridge_get_edid(struct drm_bridge *bridge,
624 					   struct drm_connector *connector)
625 {
626 	struct lt8912 *lt = bridge_to_lt8912(bridge);
627 
628 	/*
629 	 * edid must be read through the ddc bus but it must be
630 	 * given to the hdmi connector node.
631 	 */
632 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_EDID)
633 		return drm_bridge_get_edid(lt->hdmi_port, connector);
634 
635 	dev_warn(lt->dev, "The connected bridge does not supports DRM_BRIDGE_OP_EDID\n");
636 	return NULL;
637 }
638 
639 static const struct drm_bridge_funcs lt8912_bridge_funcs = {
640 	.attach = lt8912_bridge_attach,
641 	.detach = lt8912_bridge_detach,
642 	.mode_set = lt8912_bridge_mode_set,
643 	.enable = lt8912_bridge_enable,
644 	.detect = lt8912_bridge_detect,
645 	.get_edid = lt8912_bridge_get_edid,
646 };
647 
648 static int lt8912_bridge_resume(struct device *dev)
649 {
650 	struct lt8912 *lt = dev_get_drvdata(dev);
651 	int ret;
652 
653 	ret = lt8912_hard_power_on(lt);
654 	if (ret)
655 		return ret;
656 
657 	ret = lt8912_soft_power_on(lt);
658 	if (ret)
659 		return ret;
660 
661 	return lt8912_video_on(lt);
662 }
663 
664 static int lt8912_bridge_suspend(struct device *dev)
665 {
666 	struct lt8912 *lt = dev_get_drvdata(dev);
667 
668 	lt8912_hard_power_off(lt);
669 
670 	return 0;
671 }
672 
673 static DEFINE_SIMPLE_DEV_PM_OPS(lt8912_bridge_pm_ops, lt8912_bridge_suspend, lt8912_bridge_resume);
674 
675 static int lt8912_get_regulators(struct lt8912 *lt)
676 {
677 	unsigned int i;
678 	const char * const supply_names[] = {
679 		"vdd", "vccmipirx", "vccsysclk", "vcclvdstx",
680 		"vcchdmitx", "vcclvdspll", "vcchdmipll"
681 	};
682 
683 	for (i = 0; i < ARRAY_SIZE(lt->supplies); i++)
684 		lt->supplies[i].supply = supply_names[i];
685 
686 	return devm_regulator_bulk_get(lt->dev, ARRAY_SIZE(lt->supplies),
687 				       lt->supplies);
688 }
689 
690 static int lt8912_parse_dt(struct lt8912 *lt)
691 {
692 	struct gpio_desc *gp_reset;
693 	struct device *dev = lt->dev;
694 	int ret;
695 	int data_lanes;
696 	struct device_node *port_node;
697 
698 	gp_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
699 	if (IS_ERR(gp_reset)) {
700 		ret = PTR_ERR(gp_reset);
701 		if (ret != -EPROBE_DEFER)
702 			dev_err(dev, "Failed to get reset gpio: %d\n", ret);
703 		return ret;
704 	}
705 	lt->gp_reset = gp_reset;
706 
707 	data_lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, -1, 1, 4);
708 	if (data_lanes < 0) {
709 		dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
710 		return data_lanes;
711 	}
712 
713 	lt->data_lanes = data_lanes;
714 
715 	lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
716 	if (!lt->host_node) {
717 		dev_err(lt->dev, "%s: Failed to get remote port\n", __func__);
718 		return -ENODEV;
719 	}
720 
721 	port_node = of_graph_get_remote_node(dev->of_node, 1, -1);
722 	if (!port_node) {
723 		dev_err(lt->dev, "%s: Failed to get connector port\n", __func__);
724 		ret = -ENODEV;
725 		goto err_free_host_node;
726 	}
727 
728 	lt->hdmi_port = of_drm_find_bridge(port_node);
729 	if (!lt->hdmi_port) {
730 		ret = -EPROBE_DEFER;
731 		dev_err_probe(lt->dev, ret, "%s: Failed to get hdmi port\n", __func__);
732 		goto err_free_host_node;
733 	}
734 
735 	if (!of_device_is_compatible(port_node, "hdmi-connector")) {
736 		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
737 		ret = -EINVAL;
738 		goto err_free_host_node;
739 	}
740 
741 	ret = lt8912_get_regulators(lt);
742 	if (ret)
743 		goto err_free_host_node;
744 
745 	of_node_put(port_node);
746 	return 0;
747 
748 err_free_host_node:
749 	of_node_put(port_node);
750 	of_node_put(lt->host_node);
751 	return ret;
752 }
753 
754 static int lt8912_put_dt(struct lt8912 *lt)
755 {
756 	of_node_put(lt->host_node);
757 	return 0;
758 }
759 
760 static int lt8912_probe(struct i2c_client *client)
761 {
762 	static struct lt8912 *lt;
763 	int ret = 0;
764 	struct device *dev = &client->dev;
765 
766 	lt = devm_kzalloc(dev, sizeof(struct lt8912), GFP_KERNEL);
767 	if (!lt)
768 		return -ENOMEM;
769 
770 	lt->dev = dev;
771 	lt->i2c_client[0] = client;
772 
773 	ret = lt8912_parse_dt(lt);
774 	if (ret)
775 		goto err_dt_parse;
776 
777 	ret = lt8912_init_i2c(lt, client);
778 	if (ret)
779 		goto err_i2c;
780 
781 	i2c_set_clientdata(client, lt);
782 
783 	lt->bridge.funcs = &lt8912_bridge_funcs;
784 	lt->bridge.of_node = dev->of_node;
785 	lt->bridge.ops = (DRM_BRIDGE_OP_EDID |
786 			  DRM_BRIDGE_OP_DETECT);
787 
788 	drm_bridge_add(&lt->bridge);
789 
790 	ret = lt8912_attach_dsi(lt);
791 	if (ret)
792 		goto err_attach;
793 
794 	return 0;
795 
796 err_attach:
797 	drm_bridge_remove(&lt->bridge);
798 	lt8912_free_i2c(lt);
799 err_i2c:
800 	lt8912_put_dt(lt);
801 err_dt_parse:
802 	return ret;
803 }
804 
805 static void lt8912_remove(struct i2c_client *client)
806 {
807 	struct lt8912 *lt = i2c_get_clientdata(client);
808 
809 	drm_bridge_remove(&lt->bridge);
810 	lt8912_free_i2c(lt);
811 	lt8912_put_dt(lt);
812 }
813 
814 static const struct of_device_id lt8912_dt_match[] = {
815 	{.compatible = "lontium,lt8912b"},
816 	{}
817 };
818 MODULE_DEVICE_TABLE(of, lt8912_dt_match);
819 
820 static const struct i2c_device_id lt8912_id[] = {
821 	{"lt8912", 0},
822 	{},
823 };
824 MODULE_DEVICE_TABLE(i2c, lt8912_id);
825 
826 static struct i2c_driver lt8912_i2c_driver = {
827 	.driver = {
828 		.name = "lt8912",
829 		.of_match_table = lt8912_dt_match,
830 		.pm = pm_sleep_ptr(&lt8912_bridge_pm_ops),
831 	},
832 	.probe = lt8912_probe,
833 	.remove = lt8912_remove,
834 	.id_table = lt8912_id,
835 };
836 module_i2c_driver(lt8912_i2c_driver);
837 
838 MODULE_AUTHOR("Adrien Grassein <adrien.grassein@gmail.com>");
839 MODULE_DESCRIPTION("lt8912 drm driver");
840 MODULE_LICENSE("GPL v2");
841