1 /*
2  * Copyright 2012-15 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  * Authors: AMD
23  *
24  */
25 
26 /* FILE POLICY AND INTENDED USAGE:
27  *
28  * This file implements generic display communication protocols such as i2c, aux
29  * and scdc. The file should not contain any specific applications of these
30  * protocols such as display capability query, detection, or handshaking such as
31  * link training.
32  */
33 #include "link_ddc.h"
34 #include "vector.h"
35 #include "dce/dce_aux.h"
36 #include "dal_asic_id.h"
37 #include "link_dpcd.h"
38 #include "dm_helpers.h"
39 #include "atomfirmware.h"
40 
41 #define DC_LOGGER \
42 	ddc_service->ctx->logger
43 #define DC_LOGGER_INIT(logger)
44 
45 static const uint8_t DP_VGA_DONGLE_BRANCH_DEV_NAME[] = "DpVga";
46 /* DP to Dual link DVI converter */
47 static const uint8_t DP_DVI_CONVERTER_ID_4[] = "m2DVIa";
48 static const uint8_t DP_DVI_CONVERTER_ID_5[] = "3393N2";
49 
50 struct i2c_payloads {
51 	struct vector payloads;
52 };
53 
54 struct aux_payloads {
55 	struct vector payloads;
56 };
57 
i2c_payloads_create(struct dc_context * ctx,struct i2c_payloads * payloads,uint32_t count)58 static bool i2c_payloads_create(
59 		struct dc_context *ctx,
60 		struct i2c_payloads *payloads,
61 		uint32_t count)
62 {
63 	if (dal_vector_construct(
64 		&payloads->payloads, ctx, count, sizeof(struct i2c_payload)))
65 		return true;
66 
67 	return false;
68 }
69 
i2c_payloads_get(struct i2c_payloads * p)70 static struct i2c_payload *i2c_payloads_get(struct i2c_payloads *p)
71 {
72 	return (struct i2c_payload *)p->payloads.container;
73 }
74 
i2c_payloads_get_count(struct i2c_payloads * p)75 static uint32_t i2c_payloads_get_count(struct i2c_payloads *p)
76 {
77 	return p->payloads.count;
78 }
79 
i2c_payloads_destroy(struct i2c_payloads * p)80 static void i2c_payloads_destroy(struct i2c_payloads *p)
81 {
82 	if (!p)
83 		return;
84 
85 	dal_vector_destruct(&p->payloads);
86 }
87 
88 #define DDC_MIN(a, b) (((a) < (b)) ? (a) : (b))
89 
i2c_payloads_add(struct i2c_payloads * payloads,uint32_t address,uint32_t len,uint8_t * data,bool write)90 static void i2c_payloads_add(
91 	struct i2c_payloads *payloads,
92 	uint32_t address,
93 	uint32_t len,
94 	uint8_t *data,
95 	bool write)
96 {
97 	uint32_t payload_size = EDID_SEGMENT_SIZE;
98 	uint32_t pos;
99 
100 	for (pos = 0; pos < len; pos += payload_size) {
101 		struct i2c_payload payload = {
102 			.write = write,
103 			.address = address,
104 			.length = DDC_MIN(payload_size, len - pos),
105 			.data = data + pos };
106 		dal_vector_append(&payloads->payloads, &payload);
107 	}
108 
109 }
110 
ddc_service_construct(struct ddc_service * ddc_service,struct ddc_service_init_data * init_data)111 static void ddc_service_construct(
112 	struct ddc_service *ddc_service,
113 	struct ddc_service_init_data *init_data)
114 {
115 	enum connector_id connector_id =
116 		dal_graphics_object_id_get_connector_id(init_data->id);
117 
118 	struct gpio_service *gpio_service = init_data->ctx->gpio_service;
119 	struct graphics_object_i2c_info i2c_info;
120 	struct gpio_ddc_hw_info hw_info;
121 	struct dc_bios *dcb = init_data->ctx->dc_bios;
122 
123 	ddc_service->link = init_data->link;
124 	ddc_service->ctx = init_data->ctx;
125 
126 	if (init_data->is_dpia_link ||
127 	    dcb->funcs->get_i2c_info(dcb, init_data->id, &i2c_info) != BP_RESULT_OK) {
128 		ddc_service->ddc_pin = NULL;
129 	} else {
130 		DC_LOGGER_INIT(ddc_service->ctx->logger);
131 		DC_LOG_DC("BIOS object table - i2c_line: %d", i2c_info.i2c_line);
132 		DC_LOG_DC("BIOS object table - i2c_engine_id: %d", i2c_info.i2c_engine_id);
133 
134 		hw_info.ddc_channel = i2c_info.i2c_line;
135 		if (ddc_service->link != NULL)
136 			hw_info.hw_supported = i2c_info.i2c_hw_assist;
137 		else
138 			hw_info.hw_supported = false;
139 
140 		ddc_service->ddc_pin = dal_gpio_create_ddc(
141 			gpio_service,
142 			i2c_info.gpio_info.clk_a_register_index,
143 			1 << i2c_info.gpio_info.clk_a_shift,
144 			&hw_info);
145 	}
146 
147 	ddc_service->flags.EDID_QUERY_DONE_ONCE = false;
148 	ddc_service->flags.FORCE_READ_REPEATED_START = false;
149 	ddc_service->flags.EDID_STRESS_READ = false;
150 
151 	ddc_service->flags.IS_INTERNAL_DISPLAY =
152 		connector_id == CONNECTOR_ID_EDP ||
153 		connector_id == CONNECTOR_ID_LVDS;
154 
155 	ddc_service->wa.raw = 0;
156 }
157 
link_create_ddc_service(struct ddc_service_init_data * init_data)158 struct ddc_service *link_create_ddc_service(
159 	struct ddc_service_init_data *init_data)
160 {
161 	struct ddc_service *ddc_service;
162 
163 	ddc_service = kzalloc(sizeof(struct ddc_service), GFP_KERNEL);
164 
165 	if (!ddc_service)
166 		return NULL;
167 
168 	ddc_service_construct(ddc_service, init_data);
169 	return ddc_service;
170 }
171 
ddc_service_destruct(struct ddc_service * ddc)172 static void ddc_service_destruct(struct ddc_service *ddc)
173 {
174 	if (ddc->ddc_pin)
175 		dal_gpio_destroy_ddc(&ddc->ddc_pin);
176 }
177 
link_destroy_ddc_service(struct ddc_service ** ddc)178 void link_destroy_ddc_service(struct ddc_service **ddc)
179 {
180 	if (!ddc || !*ddc) {
181 		BREAK_TO_DEBUGGER();
182 		return;
183 	}
184 	ddc_service_destruct(*ddc);
185 	kfree(*ddc);
186 	*ddc = NULL;
187 }
188 
set_ddc_transaction_type(struct ddc_service * ddc,enum ddc_transaction_type type)189 void set_ddc_transaction_type(
190 	struct ddc_service *ddc,
191 	enum ddc_transaction_type type)
192 {
193 	ddc->transaction_type = type;
194 }
195 
link_is_in_aux_transaction_mode(struct ddc_service * ddc)196 bool link_is_in_aux_transaction_mode(struct ddc_service *ddc)
197 {
198 	switch (ddc->transaction_type) {
199 	case DDC_TRANSACTION_TYPE_I2C_OVER_AUX:
200 	case DDC_TRANSACTION_TYPE_I2C_OVER_AUX_WITH_DEFER:
201 	case DDC_TRANSACTION_TYPE_I2C_OVER_AUX_RETRY_DEFER:
202 		return true;
203 	default:
204 		break;
205 	}
206 	return false;
207 }
208 
set_dongle_type(struct ddc_service * ddc,enum display_dongle_type dongle_type)209 void set_dongle_type(struct ddc_service *ddc,
210 		enum display_dongle_type dongle_type)
211 {
212 	ddc->dongle_type = dongle_type;
213 }
214 
defer_delay_converter_wa(struct ddc_service * ddc,uint32_t defer_delay)215 static uint32_t defer_delay_converter_wa(
216 	struct ddc_service *ddc,
217 	uint32_t defer_delay)
218 {
219 	struct dc_link *link = ddc->link;
220 
221 	if (link->dpcd_caps.dongle_type == DISPLAY_DONGLE_DP_VGA_CONVERTER &&
222 		link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_0080E1 &&
223 		(link->dpcd_caps.branch_fw_revision[0] < 0x01 ||
224 				(link->dpcd_caps.branch_fw_revision[0] == 0x01 &&
225 				link->dpcd_caps.branch_fw_revision[1] < 0x40)) &&
226 		!memcmp(link->dpcd_caps.branch_dev_name,
227 		    DP_VGA_DONGLE_BRANCH_DEV_NAME,
228 			sizeof(link->dpcd_caps.branch_dev_name)))
229 
230 		return defer_delay > DPVGA_DONGLE_AUX_DEFER_WA_DELAY ?
231 			defer_delay : DPVGA_DONGLE_AUX_DEFER_WA_DELAY;
232 
233 	if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_0080E1 &&
234 	    !memcmp(link->dpcd_caps.branch_dev_name,
235 		    DP_DVI_CONVERTER_ID_4,
236 		    sizeof(link->dpcd_caps.branch_dev_name)))
237 		return defer_delay > I2C_OVER_AUX_DEFER_WA_DELAY ?
238 			defer_delay : I2C_OVER_AUX_DEFER_WA_DELAY;
239 	if (link->dpcd_caps.branch_dev_id == DP_BRANCH_DEVICE_ID_006037 &&
240 	    !memcmp(link->dpcd_caps.branch_dev_name,
241 		    DP_DVI_CONVERTER_ID_5,
242 		    sizeof(link->dpcd_caps.branch_dev_name)))
243 		return defer_delay > I2C_OVER_AUX_DEFER_WA_DELAY_1MS ?
244 			I2C_OVER_AUX_DEFER_WA_DELAY_1MS : defer_delay;
245 
246 	return defer_delay;
247 }
248 
249 #define DP_TRANSLATOR_DELAY 5
250 
link_get_aux_defer_delay(struct ddc_service * ddc)251 uint32_t link_get_aux_defer_delay(struct ddc_service *ddc)
252 {
253 	uint32_t defer_delay = 0;
254 
255 	switch (ddc->transaction_type) {
256 	case DDC_TRANSACTION_TYPE_I2C_OVER_AUX:
257 		if ((DISPLAY_DONGLE_DP_VGA_CONVERTER == ddc->dongle_type) ||
258 			(DISPLAY_DONGLE_DP_DVI_CONVERTER == ddc->dongle_type) ||
259 			(DISPLAY_DONGLE_DP_HDMI_CONVERTER ==
260 				ddc->dongle_type)) {
261 
262 			defer_delay = DP_TRANSLATOR_DELAY;
263 
264 			defer_delay =
265 				defer_delay_converter_wa(ddc, defer_delay);
266 
267 		} else /*sink has a delay different from an Active Converter*/
268 			defer_delay = 0;
269 		break;
270 	case DDC_TRANSACTION_TYPE_I2C_OVER_AUX_WITH_DEFER:
271 		defer_delay = DP_TRANSLATOR_DELAY;
272 		break;
273 	default:
274 		break;
275 	}
276 	return defer_delay;
277 }
278 
submit_aux_command(struct ddc_service * ddc,struct aux_payload * payload)279 static bool submit_aux_command(struct ddc_service *ddc,
280 		struct aux_payload *payload)
281 {
282 	uint32_t retrieved = 0;
283 	bool ret = false;
284 
285 	if (!ddc)
286 		return false;
287 
288 	if (!payload)
289 		return false;
290 
291 	do {
292 		struct aux_payload current_payload;
293 		bool is_end_of_payload = (retrieved + DEFAULT_AUX_MAX_DATA_SIZE) >=
294 				payload->length;
295 		uint32_t payload_length = is_end_of_payload ?
296 				payload->length - retrieved : DEFAULT_AUX_MAX_DATA_SIZE;
297 
298 		current_payload.address = payload->address;
299 		current_payload.data = &payload->data[retrieved];
300 		current_payload.defer_delay = payload->defer_delay;
301 		current_payload.i2c_over_aux = payload->i2c_over_aux;
302 		current_payload.length = payload_length;
303 		/* set mot (middle of transaction) to false if it is the last payload */
304 		current_payload.mot = is_end_of_payload ? payload->mot:true;
305 		current_payload.write_status_update = false;
306 		current_payload.reply = payload->reply;
307 		current_payload.write = payload->write;
308 
309 		ret = link_aux_transfer_with_retries_no_mutex(ddc, &current_payload);
310 
311 		retrieved += payload_length;
312 	} while (retrieved < payload->length && ret == true);
313 
314 	return ret;
315 }
316 
link_query_ddc_data(struct ddc_service * ddc,uint32_t address,uint8_t * write_buf,uint32_t write_size,uint8_t * read_buf,uint32_t read_size)317 bool link_query_ddc_data(
318 	struct ddc_service *ddc,
319 	uint32_t address,
320 	uint8_t *write_buf,
321 	uint32_t write_size,
322 	uint8_t *read_buf,
323 	uint32_t read_size)
324 {
325 	bool success = true;
326 	uint32_t payload_size =
327 		link_is_in_aux_transaction_mode(ddc) ?
328 			DEFAULT_AUX_MAX_DATA_SIZE : EDID_SEGMENT_SIZE;
329 
330 	uint32_t write_payloads =
331 		(write_size + payload_size - 1) / payload_size;
332 
333 	uint32_t read_payloads =
334 		(read_size + payload_size - 1) / payload_size;
335 
336 	uint32_t payloads_num = write_payloads + read_payloads;
337 
338 	if (!payloads_num)
339 		return false;
340 
341 	if (link_is_in_aux_transaction_mode(ddc)) {
342 		struct aux_payload payload;
343 
344 		payload.i2c_over_aux = true;
345 		payload.address = address;
346 		payload.reply = NULL;
347 		payload.defer_delay = link_get_aux_defer_delay(ddc);
348 		payload.write_status_update = false;
349 
350 		if (write_size != 0) {
351 			payload.write = true;
352 			/* should not set mot (middle of transaction) to 0
353 			 * if there are pending read payloads
354 			 */
355 			payload.mot = !(read_size == 0);
356 			payload.length = write_size;
357 			payload.data = write_buf;
358 
359 			success = submit_aux_command(ddc, &payload);
360 		}
361 
362 		if (read_size != 0 && success) {
363 			payload.write = false;
364 			/* should set mot (middle of transaction) to 0
365 			 * since it is the last payload to send
366 			 */
367 			payload.mot = false;
368 			payload.length = read_size;
369 			payload.data = read_buf;
370 
371 			success = submit_aux_command(ddc, &payload);
372 		}
373 	} else {
374 		struct i2c_command command = {0};
375 		struct i2c_payloads payloads;
376 
377 		if (!i2c_payloads_create(ddc->ctx, &payloads, payloads_num))
378 			return false;
379 
380 		command.payloads = i2c_payloads_get(&payloads);
381 		command.number_of_payloads = 0;
382 		command.engine = DDC_I2C_COMMAND_ENGINE;
383 		command.speed = ddc->ctx->dc->caps.i2c_speed_in_khz;
384 
385 		i2c_payloads_add(
386 			&payloads, address, write_size, write_buf, true);
387 
388 		i2c_payloads_add(
389 			&payloads, address, read_size, read_buf, false);
390 
391 		command.number_of_payloads =
392 			i2c_payloads_get_count(&payloads);
393 
394 		success = dm_helpers_submit_i2c(
395 				ddc->ctx,
396 				ddc->link,
397 				&command);
398 
399 		i2c_payloads_destroy(&payloads);
400 	}
401 
402 	return success;
403 }
404 
link_aux_transfer_raw(struct ddc_service * ddc,struct aux_payload * payload,enum aux_return_code_type * operation_result)405 int link_aux_transfer_raw(struct ddc_service *ddc,
406 		struct aux_payload *payload,
407 		enum aux_return_code_type *operation_result)
408 {
409 	if (ddc->ctx->dc->debug.enable_dmub_aux_for_legacy_ddc ||
410 	    !ddc->ddc_pin) {
411 		return dce_aux_transfer_dmub_raw(ddc, payload, operation_result);
412 	} else {
413 		return dce_aux_transfer_raw(ddc, payload, operation_result);
414 	}
415 }
416 
link_get_fixed_vs_pe_retimer_write_address(struct dc_link * link)417 uint32_t link_get_fixed_vs_pe_retimer_write_address(struct dc_link *link)
418 {
419 	uint32_t vendor_lttpr_write_address = 0xF004F;
420 	uint8_t offset;
421 
422 	switch (link->dpcd_caps.lttpr_caps.phy_repeater_cnt) {
423 	case 0x80: // 1 lttpr repeater
424 		offset =  1;
425 		break;
426 	case 0x40: // 2 lttpr repeaters
427 		offset = 2;
428 		break;
429 	case 0x20: // 3 lttpr repeaters
430 		offset = 3;
431 		break;
432 	case 0x10: // 4 lttpr repeaters
433 		offset = 4;
434 		break;
435 	case 0x08: // 5 lttpr repeaters
436 		offset = 5;
437 		break;
438 	case 0x04: // 6 lttpr repeaters
439 		offset = 6;
440 		break;
441 	case 0x02: // 7 lttpr repeaters
442 		offset = 7;
443 		break;
444 	case 0x01: // 8 lttpr repeaters
445 		offset = 8;
446 		break;
447 	default:
448 		offset = 0xFF;
449 	}
450 
451 	if (offset != 0xFF) {
452 		vendor_lttpr_write_address +=
453 				((DP_REPEATER_CONFIGURATION_AND_STATUS_SIZE) * (offset - 1));
454 	}
455 	return vendor_lttpr_write_address;
456 }
457 
link_get_fixed_vs_pe_retimer_read_address(struct dc_link * link)458 uint32_t link_get_fixed_vs_pe_retimer_read_address(struct dc_link *link)
459 {
460 	return link_get_fixed_vs_pe_retimer_write_address(link) + 4;
461 }
462 
link_configure_fixed_vs_pe_retimer(struct ddc_service * ddc,const uint8_t * data,uint32_t length)463 bool link_configure_fixed_vs_pe_retimer(struct ddc_service *ddc, const uint8_t *data, uint32_t length)
464 {
465 	struct aux_payload write_payload = {
466 		.i2c_over_aux = false,
467 		.write = true,
468 		.address = link_get_fixed_vs_pe_retimer_write_address(ddc->link),
469 		.length = length,
470 		.data = (uint8_t *) data,
471 		.reply = NULL,
472 		.mot = I2C_MOT_UNDEF,
473 		.write_status_update = false,
474 		.defer_delay = 0,
475 	};
476 
477 	return link_aux_transfer_with_retries_no_mutex(ddc,
478 			&write_payload);
479 }
480 
link_query_fixed_vs_pe_retimer(struct ddc_service * ddc,uint8_t * data,uint32_t length)481 bool link_query_fixed_vs_pe_retimer(struct ddc_service *ddc, uint8_t *data, uint32_t length)
482 {
483 	struct aux_payload read_payload = {
484 		.i2c_over_aux = false,
485 		.write = false,
486 		.address = link_get_fixed_vs_pe_retimer_read_address(ddc->link),
487 		.length = length,
488 		.data = data,
489 		.reply = NULL,
490 		.mot = I2C_MOT_UNDEF,
491 		.write_status_update = false,
492 		.defer_delay = 0,
493 	};
494 
495 	return link_aux_transfer_with_retries_no_mutex(ddc,
496 			&read_payload);
497 }
498 
link_aux_transfer_with_retries_no_mutex(struct ddc_service * ddc,struct aux_payload * payload)499 bool link_aux_transfer_with_retries_no_mutex(struct ddc_service *ddc,
500 		struct aux_payload *payload)
501 {
502 	return dce_aux_transfer_with_retries(ddc, payload);
503 }
504 
505 
try_to_configure_aux_timeout(struct ddc_service * ddc,uint32_t timeout)506 bool try_to_configure_aux_timeout(struct ddc_service *ddc,
507 		uint32_t timeout)
508 {
509 	bool result = false;
510 	struct ddc *ddc_pin = ddc->ddc_pin;
511 
512 	if ((ddc->link->chip_caps & EXT_DISPLAY_PATH_CAPS__DP_FIXED_VS_EN) &&
513 			!ddc->link->dc->debug.disable_fixed_vs_aux_timeout_wa &&
514 			ddc->ctx->dce_version == DCN_VERSION_3_1) {
515 		/* Fixed VS workaround for AUX timeout */
516 		const uint32_t fixed_vs_address = 0xF004F;
517 		const uint8_t fixed_vs_data[4] = {0x1, 0x22, 0x63, 0xc};
518 
519 		core_link_write_dpcd(ddc->link,
520 				fixed_vs_address,
521 				fixed_vs_data,
522 				sizeof(fixed_vs_data));
523 
524 		timeout = 3072;
525 	}
526 
527 	/* Do not try to access nonexistent DDC pin. */
528 	if (ddc->link->ep_type != DISPLAY_ENDPOINT_PHY)
529 		return true;
530 
531 	if (ddc->ctx->dc->res_pool->engines[ddc_pin->pin_data->en]->funcs->configure_timeout) {
532 		ddc->ctx->dc->res_pool->engines[ddc_pin->pin_data->en]->funcs->configure_timeout(ddc, timeout);
533 		result = true;
534 	}
535 
536 	return result;
537 }
538 
get_ddc_pin(struct ddc_service * ddc_service)539 struct ddc *get_ddc_pin(struct ddc_service *ddc_service)
540 {
541 	return ddc_service->ddc_pin;
542 }
543 
write_scdc_data(struct ddc_service * ddc_service,uint32_t pix_clk,bool lte_340_scramble)544 void write_scdc_data(struct ddc_service *ddc_service,
545 		uint32_t pix_clk,
546 		bool lte_340_scramble)
547 {
548 	bool over_340_mhz = pix_clk > 340000 ? 1 : 0;
549 	uint8_t slave_address = HDMI_SCDC_ADDRESS;
550 	uint8_t offset = HDMI_SCDC_SINK_VERSION;
551 	uint8_t sink_version = 0;
552 	uint8_t write_buffer[2] = {0};
553 	/*Lower than 340 Scramble bit from SCDC caps*/
554 
555 	if (ddc_service->link->local_sink &&
556 		ddc_service->link->local_sink->edid_caps.panel_patch.skip_scdc_overwrite)
557 		return;
558 
559 	link_query_ddc_data(ddc_service, slave_address, &offset,
560 			sizeof(offset), &sink_version, sizeof(sink_version));
561 	if (sink_version == 1) {
562 		/*Source Version = 1*/
563 		write_buffer[0] = HDMI_SCDC_SOURCE_VERSION;
564 		write_buffer[1] = 1;
565 		link_query_ddc_data(ddc_service, slave_address,
566 				write_buffer, sizeof(write_buffer), NULL, 0);
567 		/*Read Request from SCDC caps*/
568 	}
569 	write_buffer[0] = HDMI_SCDC_TMDS_CONFIG;
570 
571 	if (over_340_mhz) {
572 		write_buffer[1] = 3;
573 	} else if (lte_340_scramble) {
574 		write_buffer[1] = 1;
575 	} else {
576 		write_buffer[1] = 0;
577 	}
578 	link_query_ddc_data(ddc_service, slave_address, write_buffer,
579 			sizeof(write_buffer), NULL, 0);
580 }
581 
read_scdc_data(struct ddc_service * ddc_service)582 void read_scdc_data(struct ddc_service *ddc_service)
583 {
584 	uint8_t slave_address = HDMI_SCDC_ADDRESS;
585 	uint8_t offset = HDMI_SCDC_TMDS_CONFIG;
586 	uint8_t tmds_config = 0;
587 
588 	if (ddc_service->link->local_sink &&
589 		ddc_service->link->local_sink->edid_caps.panel_patch.skip_scdc_overwrite)
590 		return;
591 
592 	link_query_ddc_data(ddc_service, slave_address, &offset,
593 			sizeof(offset), &tmds_config, sizeof(tmds_config));
594 	if (tmds_config & 0x1) {
595 		union hdmi_scdc_status_flags_data status_data = {0};
596 		uint8_t scramble_status = 0;
597 
598 		offset = HDMI_SCDC_SCRAMBLER_STATUS;
599 		link_query_ddc_data(ddc_service, slave_address,
600 				&offset, sizeof(offset), &scramble_status,
601 				sizeof(scramble_status));
602 		offset = HDMI_SCDC_STATUS_FLAGS;
603 		link_query_ddc_data(ddc_service, slave_address,
604 				&offset, sizeof(offset), &status_data.byte,
605 				sizeof(status_data.byte));
606 	}
607 }
608