xref: /linux/drivers/gpu/drm/bridge/lontium-lt8912b.c (revision 051ad278)
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 	u8 data_lanes;
47 	bool is_power_on;
48 	bool is_attached;
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 static int lt8912_write_lvds_config(struct lt8912 *lt)
169 {
170 	const struct reg_sequence seq[] = {
171 		{0x44, 0x30},
172 		{0x51, 0x05},
173 		{0x50, 0x24},
174 		{0x51, 0x2d},
175 		{0x52, 0x04},
176 		{0x69, 0x0e},
177 		{0x69, 0x8e},
178 		{0x6a, 0x00},
179 		{0x6c, 0xb8},
180 		{0x6b, 0x51},
181 		{0x04, 0xfb},
182 		{0x04, 0xff},
183 		{0x7f, 0x00},
184 		{0xa8, 0x13},
185 		{0x02, 0xf7},
186 		{0x02, 0xff},
187 		{0x03, 0xcf},
188 		{0x03, 0xff},
189 	};
190 
191 	return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq));
192 };
193 
194 static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b)
195 {
196 	return container_of(b, struct lt8912, bridge);
197 }
198 
199 static inline struct lt8912 *connector_to_lt8912(struct drm_connector *c)
200 {
201 	return container_of(c, struct lt8912, connector);
202 }
203 
204 static const struct regmap_config lt8912_regmap_config = {
205 	.reg_bits = 8,
206 	.val_bits = 8,
207 	.max_register = 0xff,
208 };
209 
210 static int lt8912_init_i2c(struct lt8912 *lt, struct i2c_client *client)
211 {
212 	unsigned int i;
213 	/*
214 	 * At this time we only initialize 2 chips, but the lt8912 provides
215 	 * a third interface for the audio over HDMI configuration.
216 	 */
217 	struct i2c_board_info info[] = {
218 		{ I2C_BOARD_INFO("lt8912p0", I2C_ADDR_MAIN), },
219 		{ I2C_BOARD_INFO("lt8912p1", I2C_ADDR_CEC_DSI), },
220 	};
221 
222 	if (!lt)
223 		return -ENODEV;
224 
225 	for (i = 0; i < ARRAY_SIZE(info); i++) {
226 		if (i > 0) {
227 			lt->i2c_client[i] = i2c_new_dummy_device(client->adapter,
228 								 info[i].addr);
229 			if (IS_ERR(lt->i2c_client[i]))
230 				return PTR_ERR(lt->i2c_client[i]);
231 		}
232 
233 		lt->regmap[i] = devm_regmap_init_i2c(lt->i2c_client[i],
234 						     &lt8912_regmap_config);
235 		if (IS_ERR(lt->regmap[i]))
236 			return PTR_ERR(lt->regmap[i]);
237 	}
238 	return 0;
239 }
240 
241 static int lt8912_free_i2c(struct lt8912 *lt)
242 {
243 	unsigned int i;
244 
245 	for (i = 1; i < I2C_MAX_IDX; i++)
246 		i2c_unregister_device(lt->i2c_client[i]);
247 
248 	return 0;
249 }
250 
251 static int lt8912_hard_power_on(struct lt8912 *lt)
252 {
253 	gpiod_set_value_cansleep(lt->gp_reset, 0);
254 	msleep(20);
255 
256 	return 0;
257 }
258 
259 static void lt8912_hard_power_off(struct lt8912 *lt)
260 {
261 	gpiod_set_value_cansleep(lt->gp_reset, 1);
262 	msleep(20);
263 	lt->is_power_on = false;
264 }
265 
266 static int lt8912_video_setup(struct lt8912 *lt)
267 {
268 	u32 hactive, h_total, hpw, hfp, hbp;
269 	u32 vactive, v_total, vpw, vfp, vbp;
270 	u8 settle = 0x08;
271 	int ret, hsync_activehigh, vsync_activehigh;
272 
273 	if (!lt)
274 		return -EINVAL;
275 
276 	hactive = lt->mode.hactive;
277 	hfp = lt->mode.hfront_porch;
278 	hpw = lt->mode.hsync_len;
279 	hbp = lt->mode.hback_porch;
280 	h_total = hactive + hfp + hpw + hbp;
281 	hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH;
282 
283 	vactive = lt->mode.vactive;
284 	vfp = lt->mode.vfront_porch;
285 	vpw = lt->mode.vsync_len;
286 	vbp = lt->mode.vback_porch;
287 	v_total = vactive + vfp + vpw + vbp;
288 	vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH;
289 
290 	if (vactive <= 600)
291 		settle = 0x04;
292 	else if (vactive == 1080)
293 		settle = 0x0a;
294 
295 	ret = regmap_write(lt->regmap[I2C_CEC_DSI], 0x10, 0x01);
296 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x11, settle);
297 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x18, hpw);
298 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x19, vpw);
299 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1c, hactive & 0xff);
300 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x1d, hactive >> 8);
301 
302 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x2f, 0x0c);
303 
304 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x34, h_total & 0xff);
305 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x35, h_total >> 8);
306 
307 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x36, v_total & 0xff);
308 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x37, v_total >> 8);
309 
310 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x38, vbp & 0xff);
311 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x39, vbp >> 8);
312 
313 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3a, vfp & 0xff);
314 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3b, vfp >> 8);
315 
316 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3c, hbp & 0xff);
317 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3d, hbp >> 8);
318 
319 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff);
320 	ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8);
321 
322 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0),
323 				  vsync_activehigh ? BIT(0) : 0);
324 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1),
325 				  hsync_activehigh ? BIT(1) : 0);
326 	ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0),
327 				  lt->connector.display_info.is_hdmi ? BIT(0) : 0);
328 
329 	return ret;
330 }
331 
332 static int lt8912_soft_power_on(struct lt8912 *lt)
333 {
334 	if (!lt->is_power_on) {
335 		u32 lanes = lt->data_lanes;
336 
337 		lt8912_write_init_config(lt);
338 		regmap_write(lt->regmap[I2C_CEC_DSI], 0x13, lanes & 3);
339 
340 		lt8912_write_mipi_basic_config(lt);
341 
342 		lt->is_power_on = true;
343 	}
344 
345 	return 0;
346 }
347 
348 static int lt8912_video_on(struct lt8912 *lt)
349 {
350 	int ret;
351 
352 	ret = lt8912_video_setup(lt);
353 	if (ret < 0)
354 		goto end;
355 
356 	ret = lt8912_write_dds_config(lt);
357 	if (ret < 0)
358 		goto end;
359 
360 	ret = lt8912_write_rxlogicres_config(lt);
361 	if (ret < 0)
362 		goto end;
363 
364 	ret = lt8912_write_lvds_config(lt);
365 	if (ret < 0)
366 		goto end;
367 
368 end:
369 	return ret;
370 }
371 
372 static enum drm_connector_status lt8912_check_cable_status(struct lt8912 *lt)
373 {
374 	int ret;
375 	unsigned int reg_val;
376 
377 	ret = regmap_read(lt->regmap[I2C_MAIN], 0xC1, &reg_val);
378 	if (ret)
379 		return connector_status_unknown;
380 
381 	if (reg_val & BIT(7))
382 		return connector_status_connected;
383 
384 	return connector_status_disconnected;
385 }
386 
387 static enum drm_connector_status
388 lt8912_connector_detect(struct drm_connector *connector, bool force)
389 {
390 	struct lt8912 *lt = connector_to_lt8912(connector);
391 
392 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
393 		return drm_bridge_detect(lt->hdmi_port);
394 
395 	return lt8912_check_cable_status(lt);
396 }
397 
398 static const struct drm_connector_funcs lt8912_connector_funcs = {
399 	.detect = lt8912_connector_detect,
400 	.fill_modes = drm_helper_probe_single_connector_modes,
401 	.destroy = drm_connector_cleanup,
402 	.reset = drm_atomic_helper_connector_reset,
403 	.atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
404 	.atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
405 };
406 
407 static enum drm_mode_status
408 lt8912_connector_mode_valid(struct drm_connector *connector,
409 			    struct drm_display_mode *mode)
410 {
411 	if (mode->clock > 150000)
412 		return MODE_CLOCK_HIGH;
413 
414 	if (mode->hdisplay > 1920)
415 		return MODE_BAD_HVALUE;
416 
417 	if (mode->vdisplay > 1080)
418 		return MODE_BAD_VVALUE;
419 
420 	return MODE_OK;
421 }
422 
423 static int lt8912_connector_get_modes(struct drm_connector *connector)
424 {
425 	struct edid *edid;
426 	int ret = -1;
427 	int num = 0;
428 	struct lt8912 *lt = connector_to_lt8912(connector);
429 	u32 bus_format = MEDIA_BUS_FMT_RGB888_1X24;
430 
431 	edid = drm_bridge_get_edid(lt->hdmi_port, connector);
432 	if (edid) {
433 		drm_connector_update_edid_property(connector, edid);
434 		num = drm_add_edid_modes(connector, edid);
435 	} else {
436 		return ret;
437 	}
438 
439 	ret = drm_display_info_set_bus_formats(&connector->display_info,
440 					       &bus_format, 1);
441 	if (ret)
442 		num = ret;
443 
444 	kfree(edid);
445 	return num;
446 }
447 
448 static const struct drm_connector_helper_funcs lt8912_connector_helper_funcs = {
449 	.get_modes = lt8912_connector_get_modes,
450 	.mode_valid = lt8912_connector_mode_valid,
451 };
452 
453 static void lt8912_bridge_mode_set(struct drm_bridge *bridge,
454 				   const struct drm_display_mode *mode,
455 				   const struct drm_display_mode *adj)
456 {
457 	struct lt8912 *lt = bridge_to_lt8912(bridge);
458 
459 	drm_display_mode_to_videomode(adj, &lt->mode);
460 }
461 
462 static void lt8912_bridge_enable(struct drm_bridge *bridge)
463 {
464 	struct lt8912 *lt = bridge_to_lt8912(bridge);
465 
466 	lt8912_video_on(lt);
467 }
468 
469 static int lt8912_attach_dsi(struct lt8912 *lt)
470 {
471 	struct device *dev = lt->dev;
472 	struct mipi_dsi_host *host;
473 	struct mipi_dsi_device *dsi;
474 	int ret = -1;
475 	const struct mipi_dsi_device_info info = { .type = "lt8912",
476 						   .channel = 0,
477 						   .node = NULL,
478 						 };
479 
480 	host = of_find_mipi_dsi_host_by_node(lt->host_node);
481 	if (!host) {
482 		dev_err(dev, "failed to find dsi host\n");
483 		return -EPROBE_DEFER;
484 	}
485 
486 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
487 	if (IS_ERR(dsi)) {
488 		ret = PTR_ERR(dsi);
489 		dev_err(dev, "failed to create dsi device (%d)\n", ret);
490 		return ret;
491 	}
492 
493 	lt->dsi = dsi;
494 
495 	dsi->lanes = lt->data_lanes;
496 	dsi->format = MIPI_DSI_FMT_RGB888;
497 
498 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
499 			  MIPI_DSI_MODE_VIDEO_BURST |
500 			  MIPI_DSI_MODE_LPM |
501 			  MIPI_DSI_MODE_NO_EOT_PACKET;
502 
503 	ret = devm_mipi_dsi_attach(dev, dsi);
504 	if (ret < 0) {
505 		dev_err(dev, "failed to attach dsi to host\n");
506 		return ret;
507 	}
508 
509 	return 0;
510 }
511 
512 static int lt8912_bridge_connector_init(struct drm_bridge *bridge)
513 {
514 	int ret;
515 	struct lt8912 *lt = bridge_to_lt8912(bridge);
516 	struct drm_connector *connector = &lt->connector;
517 
518 	connector->polled = DRM_CONNECTOR_POLL_CONNECT |
519 			    DRM_CONNECTOR_POLL_DISCONNECT;
520 
521 	ret = drm_connector_init(bridge->dev, connector,
522 				 &lt8912_connector_funcs,
523 				 lt->hdmi_port->type);
524 	if (ret)
525 		goto exit;
526 
527 	drm_connector_helper_add(connector, &lt8912_connector_helper_funcs);
528 
529 	connector->dpms = DRM_MODE_DPMS_OFF;
530 	drm_connector_attach_encoder(connector, bridge->encoder);
531 
532 exit:
533 	return ret;
534 }
535 
536 static int lt8912_bridge_attach(struct drm_bridge *bridge,
537 				enum drm_bridge_attach_flags flags)
538 {
539 	struct lt8912 *lt = bridge_to_lt8912(bridge);
540 	int ret;
541 
542 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR)) {
543 		ret = lt8912_bridge_connector_init(bridge);
544 		if (ret) {
545 			dev_err(lt->dev, "Failed to init bridge ! (%d)\n", ret);
546 			return ret;
547 		}
548 	}
549 
550 	ret = lt8912_hard_power_on(lt);
551 	if (ret)
552 		return ret;
553 
554 	ret = lt8912_soft_power_on(lt);
555 	if (ret)
556 		goto error;
557 
558 	lt->is_attached = true;
559 
560 	return 0;
561 
562 error:
563 	lt8912_hard_power_off(lt);
564 	return ret;
565 }
566 
567 static void lt8912_bridge_detach(struct drm_bridge *bridge)
568 {
569 	struct lt8912 *lt = bridge_to_lt8912(bridge);
570 
571 	if (lt->is_attached) {
572 		lt8912_hard_power_off(lt);
573 		drm_connector_unregister(&lt->connector);
574 		drm_connector_cleanup(&lt->connector);
575 	}
576 }
577 
578 static enum drm_connector_status
579 lt8912_bridge_detect(struct drm_bridge *bridge)
580 {
581 	struct lt8912 *lt = bridge_to_lt8912(bridge);
582 
583 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_DETECT)
584 		return drm_bridge_detect(lt->hdmi_port);
585 
586 	return lt8912_check_cable_status(lt);
587 }
588 
589 static struct edid *lt8912_bridge_get_edid(struct drm_bridge *bridge,
590 					   struct drm_connector *connector)
591 {
592 	struct lt8912 *lt = bridge_to_lt8912(bridge);
593 
594 	/*
595 	 * edid must be read through the ddc bus but it must be
596 	 * given to the hdmi connector node.
597 	 */
598 	if (lt->hdmi_port->ops & DRM_BRIDGE_OP_EDID)
599 		return drm_bridge_get_edid(lt->hdmi_port, connector);
600 
601 	dev_warn(lt->dev, "The connected bridge does not supports DRM_BRIDGE_OP_EDID\n");
602 	return NULL;
603 }
604 
605 static const struct drm_bridge_funcs lt8912_bridge_funcs = {
606 	.attach = lt8912_bridge_attach,
607 	.detach = lt8912_bridge_detach,
608 	.mode_set = lt8912_bridge_mode_set,
609 	.enable = lt8912_bridge_enable,
610 	.detect = lt8912_bridge_detect,
611 	.get_edid = lt8912_bridge_get_edid,
612 };
613 
614 static int lt8912_parse_dt(struct lt8912 *lt)
615 {
616 	struct gpio_desc *gp_reset;
617 	struct device *dev = lt->dev;
618 	int ret;
619 	int data_lanes;
620 	struct device_node *port_node;
621 
622 	gp_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
623 	if (IS_ERR(gp_reset)) {
624 		ret = PTR_ERR(gp_reset);
625 		if (ret != -EPROBE_DEFER)
626 			dev_err(dev, "Failed to get reset gpio: %d\n", ret);
627 		return ret;
628 	}
629 	lt->gp_reset = gp_reset;
630 
631 	data_lanes = drm_of_get_data_lanes_count_ep(dev->of_node, 0, -1, 1, 4);
632 	if (data_lanes < 0) {
633 		dev_err(lt->dev, "%s: Bad data-lanes property\n", __func__);
634 		return data_lanes;
635 	}
636 
637 	lt->data_lanes = data_lanes;
638 
639 	lt->host_node = of_graph_get_remote_node(dev->of_node, 0, -1);
640 	if (!lt->host_node) {
641 		dev_err(lt->dev, "%s: Failed to get remote port\n", __func__);
642 		return -ENODEV;
643 	}
644 
645 	port_node = of_graph_get_remote_node(dev->of_node, 1, -1);
646 	if (!port_node) {
647 		dev_err(lt->dev, "%s: Failed to get connector port\n", __func__);
648 		ret = -ENODEV;
649 		goto err_free_host_node;
650 	}
651 
652 	lt->hdmi_port = of_drm_find_bridge(port_node);
653 	if (!lt->hdmi_port) {
654 		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
655 		ret = -ENODEV;
656 		goto err_free_host_node;
657 	}
658 
659 	if (!of_device_is_compatible(port_node, "hdmi-connector")) {
660 		dev_err(lt->dev, "%s: Failed to get hdmi port\n", __func__);
661 		ret = -EINVAL;
662 		goto err_free_host_node;
663 	}
664 
665 	of_node_put(port_node);
666 	return 0;
667 
668 err_free_host_node:
669 	of_node_put(port_node);
670 	of_node_put(lt->host_node);
671 	return ret;
672 }
673 
674 static int lt8912_put_dt(struct lt8912 *lt)
675 {
676 	of_node_put(lt->host_node);
677 	return 0;
678 }
679 
680 static int lt8912_probe(struct i2c_client *client,
681 			const struct i2c_device_id *id)
682 {
683 	static struct lt8912 *lt;
684 	int ret = 0;
685 	struct device *dev = &client->dev;
686 
687 	lt = devm_kzalloc(dev, sizeof(struct lt8912), GFP_KERNEL);
688 	if (!lt)
689 		return -ENOMEM;
690 
691 	lt->dev = dev;
692 	lt->i2c_client[0] = client;
693 
694 	ret = lt8912_parse_dt(lt);
695 	if (ret)
696 		goto err_dt_parse;
697 
698 	ret = lt8912_init_i2c(lt, client);
699 	if (ret)
700 		goto err_i2c;
701 
702 	i2c_set_clientdata(client, lt);
703 
704 	lt->bridge.funcs = &lt8912_bridge_funcs;
705 	lt->bridge.of_node = dev->of_node;
706 	lt->bridge.ops = (DRM_BRIDGE_OP_EDID |
707 			  DRM_BRIDGE_OP_DETECT);
708 
709 	drm_bridge_add(&lt->bridge);
710 
711 	ret = lt8912_attach_dsi(lt);
712 	if (ret)
713 		goto err_attach;
714 
715 	return 0;
716 
717 err_attach:
718 	drm_bridge_remove(&lt->bridge);
719 	lt8912_free_i2c(lt);
720 err_i2c:
721 	lt8912_put_dt(lt);
722 err_dt_parse:
723 	return ret;
724 }
725 
726 static int lt8912_remove(struct i2c_client *client)
727 {
728 	struct lt8912 *lt = i2c_get_clientdata(client);
729 
730 	lt8912_bridge_detach(&lt->bridge);
731 	drm_bridge_remove(&lt->bridge);
732 	lt8912_free_i2c(lt);
733 	lt8912_put_dt(lt);
734 	return 0;
735 }
736 
737 static const struct of_device_id lt8912_dt_match[] = {
738 	{.compatible = "lontium,lt8912b"},
739 	{}
740 };
741 MODULE_DEVICE_TABLE(of, lt8912_dt_match);
742 
743 static const struct i2c_device_id lt8912_id[] = {
744 	{"lt8912", 0},
745 	{},
746 };
747 MODULE_DEVICE_TABLE(i2c, lt8912_id);
748 
749 static struct i2c_driver lt8912_i2c_driver = {
750 	.driver = {
751 		.name = "lt8912",
752 		.of_match_table = lt8912_dt_match,
753 	},
754 	.probe = lt8912_probe,
755 	.remove = lt8912_remove,
756 	.id_table = lt8912_id,
757 };
758 module_i2c_driver(lt8912_i2c_driver);
759 
760 MODULE_AUTHOR("Adrien Grassein <adrien.grassein@gmail.com>");
761 MODULE_DESCRIPTION("lt8912 drm driver");
762 MODULE_LICENSE("GPL v2");
763