1 /*
2  * Copyright (C) 2012 Samsung Electronics
3  *
4  * Author: Donghwa Lee <dh09.lee@samsung.com>
5  *
6  * SPDX-License-Identifier:	GPL-2.0+
7  */
8 
9 #include <config.h>
10 #include <common.h>
11 #include <linux/err.h>
12 #include <asm/arch/cpu.h>
13 #include <asm/arch/dp_info.h>
14 #include <asm/arch/dp.h>
15 #include <fdtdec.h>
16 #include <libfdt.h>
17 #include "exynos_dp_lowlevel.h"
18 
19 /* Declare global data pointer */
20 DECLARE_GLOBAL_DATA_PTR;
21 
22 static void exynos_dp_enable_video_input(struct exynos_dp *dp_regs,
23 					 unsigned int enable)
24 {
25 	unsigned int reg;
26 
27 	reg = readl(&dp_regs->video_ctl1);
28 	reg &= ~VIDEO_EN_MASK;
29 
30 	/* enable video input */
31 	if (enable)
32 		reg |= VIDEO_EN_MASK;
33 
34 	writel(reg, &dp_regs->video_ctl1);
35 
36 	return;
37 }
38 
39 void exynos_dp_enable_video_bist(struct exynos_dp *dp_regs, unsigned int enable)
40 {
41 	/* enable video bist */
42 	unsigned int reg;
43 
44 	reg = readl(&dp_regs->video_ctl4);
45 	reg &= ~VIDEO_BIST_MASK;
46 
47 	/* enable video bist */
48 	if (enable)
49 		reg |= VIDEO_BIST_MASK;
50 
51 	writel(reg, &dp_regs->video_ctl4);
52 
53 	return;
54 }
55 
56 void exynos_dp_enable_video_mute(struct exynos_dp *dp_regs, unsigned int enable)
57 {
58 	unsigned int reg;
59 
60 	reg = readl(&dp_regs->video_ctl1);
61 	reg &= ~(VIDEO_MUTE_MASK);
62 	if (enable)
63 		reg |= VIDEO_MUTE_MASK;
64 
65 	writel(reg, &dp_regs->video_ctl1);
66 
67 	return;
68 }
69 
70 
71 static void exynos_dp_init_analog_param(struct exynos_dp *dp_regs)
72 {
73 	unsigned int reg;
74 
75 	/*
76 	 * Set termination
77 	 * Normal bandgap, Normal swing, Tx terminal registor 61 ohm
78 	 * 24M Phy clock, TX digital logic power is 100:1.0625V
79 	 */
80 	reg = SEL_BG_NEW_BANDGAP | TX_TERMINAL_CTRL_61_OHM |
81 		SWING_A_30PER_G_NORMAL;
82 	writel(reg, &dp_regs->analog_ctl1);
83 
84 	reg = SEL_24M | TX_DVDD_BIT_1_0625V;
85 	writel(reg, &dp_regs->analog_ctl2);
86 
87 	/*
88 	 * Set power source for internal clk driver to 1.0625v.
89 	 * Select current reference of TX driver current to 00:Ipp/2+Ic/2.
90 	 * Set VCO range of PLL +- 0uA
91 	 */
92 	reg = DRIVE_DVDD_BIT_1_0625V | SEL_CURRENT_DEFAULT | VCO_BIT_000_MICRO;
93 	writel(reg, &dp_regs->analog_ctl3);
94 
95 	/*
96 	 * Set AUX TX terminal resistor to 102 ohm
97 	 * Set AUX channel amplitude control
98 	 */
99 	reg = PD_RING_OSC | AUX_TERMINAL_CTRL_52_OHM | TX_CUR1_2X | TX_CUR_4_MA;
100 	writel(reg, &dp_regs->pll_filter_ctl1);
101 
102 	/*
103 	 * PLL loop filter bandwidth
104 	 * For 2.7Gbps: 175KHz, For 1.62Gbps: 234KHz
105 	 * PLL digital power select: 1.2500V
106 	 */
107 	reg = CH3_AMP_0_MV | CH2_AMP_0_MV | CH1_AMP_0_MV | CH0_AMP_0_MV;
108 
109 	writel(reg, &dp_regs->amp_tuning_ctl);
110 
111 	/*
112 	 * PLL loop filter bandwidth
113 	 * For 2.7Gbps: 175KHz, For 1.62Gbps: 234KHz
114 	 * PLL digital power select: 1.1250V
115 	 */
116 	reg = DP_PLL_LOOP_BIT_DEFAULT | DP_PLL_REF_BIT_1_1250V;
117 	writel(reg, &dp_regs->pll_ctl);
118 }
119 
120 static void exynos_dp_init_interrupt(struct exynos_dp *dp_regs)
121 {
122 	/* Set interrupt registers to initial states */
123 
124 	/*
125 	 * Disable interrupt
126 	 * INT pin assertion polarity. It must be configured
127 	 * correctly according to ICU setting.
128 	 * 1 = assert high, 0 = assert low
129 	 */
130 	writel(INT_POL, &dp_regs->int_ctl);
131 
132 	/* Clear pending registers */
133 	writel(0xff, &dp_regs->common_int_sta1);
134 	writel(0xff, &dp_regs->common_int_sta2);
135 	writel(0xff, &dp_regs->common_int_sta3);
136 	writel(0xff, &dp_regs->common_int_sta4);
137 	writel(0xff, &dp_regs->int_sta);
138 
139 	/* 0:mask,1: unmask */
140 	writel(0x00, &dp_regs->int_sta_mask1);
141 	writel(0x00, &dp_regs->int_sta_mask2);
142 	writel(0x00, &dp_regs->int_sta_mask3);
143 	writel(0x00, &dp_regs->int_sta_mask4);
144 	writel(0x00, &dp_regs->int_sta_mask);
145 }
146 
147 void exynos_dp_reset(struct exynos_dp *dp_regs)
148 {
149 	unsigned int reg_func_1;
150 
151 	/* dp tx sw reset */
152 	writel(RESET_DP_TX, &dp_regs->tx_sw_reset);
153 
154 	exynos_dp_enable_video_input(dp_regs, DP_DISABLE);
155 	exynos_dp_enable_video_bist(dp_regs, DP_DISABLE);
156 	exynos_dp_enable_video_mute(dp_regs, DP_DISABLE);
157 
158 	/* software reset */
159 	reg_func_1 = MASTER_VID_FUNC_EN_N | SLAVE_VID_FUNC_EN_N |
160 		AUD_FIFO_FUNC_EN_N | AUD_FUNC_EN_N |
161 		HDCP_FUNC_EN_N | SW_FUNC_EN_N;
162 
163 	writel(reg_func_1, &dp_regs->func_en1);
164 	writel(reg_func_1, &dp_regs->func_en2);
165 
166 	mdelay(1);
167 
168 	exynos_dp_init_analog_param(dp_regs);
169 	exynos_dp_init_interrupt(dp_regs);
170 
171 	return;
172 }
173 
174 void exynos_dp_enable_sw_func(struct exynos_dp *dp_regs, unsigned int enable)
175 {
176 	unsigned int reg;
177 
178 	reg = readl(&dp_regs->func_en1);
179 	reg &= ~(SW_FUNC_EN_N);
180 
181 	if (!enable)
182 		reg |= SW_FUNC_EN_N;
183 
184 	writel(reg, &dp_regs->func_en1);
185 
186 	return;
187 }
188 
189 unsigned int exynos_dp_set_analog_power_down(struct exynos_dp *dp_regs,
190 					     unsigned int block, u32 enable)
191 {
192 	unsigned int reg;
193 
194 	reg = readl(&dp_regs->phy_pd);
195 	switch (block) {
196 	case AUX_BLOCK:
197 		reg &= ~(AUX_PD);
198 		if (enable)
199 			reg |= AUX_PD;
200 		break;
201 	case CH0_BLOCK:
202 		reg &= ~(CH0_PD);
203 		if (enable)
204 			reg |= CH0_PD;
205 		break;
206 	case CH1_BLOCK:
207 		reg &= ~(CH1_PD);
208 		if (enable)
209 			reg |= CH1_PD;
210 		break;
211 	case CH2_BLOCK:
212 		reg &= ~(CH2_PD);
213 		if (enable)
214 			reg |= CH2_PD;
215 		break;
216 	case CH3_BLOCK:
217 		reg &= ~(CH3_PD);
218 		if (enable)
219 			reg |= CH3_PD;
220 		break;
221 	case ANALOG_TOTAL:
222 		reg &= ~PHY_PD;
223 		if (enable)
224 			reg |= PHY_PD;
225 		break;
226 	case POWER_ALL:
227 		reg &= ~(PHY_PD | AUX_PD | CH0_PD | CH1_PD | CH2_PD |
228 			CH3_PD);
229 		if (enable)
230 			reg |= (PHY_PD | AUX_PD | CH0_PD | CH1_PD |
231 				CH2_PD | CH3_PD);
232 		break;
233 	default:
234 		printf("DP undefined block number : %d\n",  block);
235 		return -1;
236 	}
237 
238 	writel(reg, &dp_regs->phy_pd);
239 
240 	return 0;
241 }
242 
243 unsigned int exynos_dp_get_pll_lock_status(struct exynos_dp *dp_regs)
244 {
245 	unsigned int reg;
246 
247 	reg = readl(&dp_regs->debug_ctl);
248 
249 	if (reg & PLL_LOCK)
250 		return PLL_LOCKED;
251 	else
252 		return PLL_UNLOCKED;
253 }
254 
255 static void exynos_dp_set_pll_power(struct exynos_dp *dp_regs,
256 				    unsigned int enable)
257 {
258 	unsigned int reg;
259 
260 	reg = readl(&dp_regs->pll_ctl);
261 	reg &= ~(DP_PLL_PD);
262 
263 	if (!enable)
264 		reg |= DP_PLL_PD;
265 
266 	writel(reg, &dp_regs->pll_ctl);
267 }
268 
269 int exynos_dp_init_analog_func(struct exynos_dp *dp_regs)
270 {
271 	int ret = EXYNOS_DP_SUCCESS;
272 	unsigned int retry_cnt = 10;
273 	unsigned int reg;
274 
275 	/* Power On All Analog block */
276 	exynos_dp_set_analog_power_down(dp_regs, POWER_ALL, DP_DISABLE);
277 
278 	reg = PLL_LOCK_CHG;
279 	writel(reg, &dp_regs->common_int_sta1);
280 
281 	reg = readl(&dp_regs->debug_ctl);
282 	reg &= ~(F_PLL_LOCK | PLL_LOCK_CTRL);
283 	writel(reg, &dp_regs->debug_ctl);
284 
285 	/* Assert DP PLL Reset */
286 	reg = readl(&dp_regs->pll_ctl);
287 	reg |= DP_PLL_RESET;
288 	writel(reg, &dp_regs->pll_ctl);
289 
290 	mdelay(1);
291 
292 	/* Deassert DP PLL Reset */
293 	reg = readl(&dp_regs->pll_ctl);
294 	reg &= ~(DP_PLL_RESET);
295 	writel(reg, &dp_regs->pll_ctl);
296 
297 	exynos_dp_set_pll_power(dp_regs, DP_ENABLE);
298 
299 	while (exynos_dp_get_pll_lock_status(dp_regs) == PLL_UNLOCKED) {
300 		mdelay(1);
301 		retry_cnt--;
302 		if (retry_cnt == 0) {
303 			printf("DP dp's pll lock failed : retry : %d\n",
304 					retry_cnt);
305 			return -EINVAL;
306 		}
307 	}
308 
309 	debug("dp's pll lock success(%d)\n", retry_cnt);
310 
311 	/* Enable Serdes FIFO function and Link symbol clock domain module */
312 	reg = readl(&dp_regs->func_en2);
313 	reg &= ~(SERDES_FIFO_FUNC_EN_N | LS_CLK_DOMAIN_FUNC_EN_N
314 		| AUX_FUNC_EN_N);
315 	writel(reg, &dp_regs->func_en2);
316 
317 	return ret;
318 }
319 
320 void exynos_dp_init_hpd(struct exynos_dp *dp_regs)
321 {
322 	unsigned int reg;
323 
324 	/* Clear interrupts related to Hot Plug Detect */
325 	reg = HOTPLUG_CHG | HPD_LOST | PLUG;
326 	writel(reg, &dp_regs->common_int_sta4);
327 
328 	reg = INT_HPD;
329 	writel(reg, &dp_regs->int_sta);
330 
331 	reg = readl(&dp_regs->sys_ctl3);
332 	reg &= ~(F_HPD | HPD_CTRL);
333 	writel(reg, &dp_regs->sys_ctl3);
334 
335 	return;
336 }
337 
338 static inline void exynos_dp_reset_aux(struct exynos_dp *dp_regs)
339 {
340 	unsigned int reg;
341 
342 	/* Disable AUX channel module */
343 	reg = readl(&dp_regs->func_en2);
344 	reg |= AUX_FUNC_EN_N;
345 	writel(reg, &dp_regs->func_en2);
346 
347 	return;
348 }
349 
350 void exynos_dp_init_aux(struct exynos_dp *dp_regs)
351 {
352 	unsigned int reg;
353 
354 	/* Clear interrupts related to AUX channel */
355 	reg = RPLY_RECEIV | AUX_ERR;
356 	writel(reg, &dp_regs->int_sta);
357 
358 	exynos_dp_reset_aux(dp_regs);
359 
360 	/* Disable AUX transaction H/W retry */
361 	reg = AUX_BIT_PERIOD_EXPECTED_DELAY(3) | AUX_HW_RETRY_COUNT_SEL(3)|
362 		AUX_HW_RETRY_INTERVAL_600_MICROSECONDS;
363 	writel(reg, &dp_regs->aux_hw_retry_ctl);
364 
365 	/* Receive AUX Channel DEFER commands equal to DEFER_COUNT*64 */
366 	reg = DEFER_CTRL_EN | DEFER_COUNT(1);
367 	writel(reg, &dp_regs->aux_ch_defer_ctl);
368 
369 	/* Enable AUX channel module */
370 	reg = readl(&dp_regs->func_en2);
371 	reg &= ~AUX_FUNC_EN_N;
372 	writel(reg, &dp_regs->func_en2);
373 
374 	return;
375 }
376 
377 void exynos_dp_config_interrupt(struct exynos_dp *dp_regs)
378 {
379 	unsigned int reg;
380 
381 	/* 0: mask, 1: unmask */
382 	reg = COMMON_INT_MASK_1;
383 	writel(reg, &dp_regs->common_int_mask1);
384 
385 	reg = COMMON_INT_MASK_2;
386 	writel(reg, &dp_regs->common_int_mask2);
387 
388 	reg = COMMON_INT_MASK_3;
389 	writel(reg, &dp_regs->common_int_mask3);
390 
391 	reg = COMMON_INT_MASK_4;
392 	writel(reg, &dp_regs->common_int_mask4);
393 
394 	reg = INT_STA_MASK;
395 	writel(reg, &dp_regs->int_sta_mask);
396 
397 	return;
398 }
399 
400 unsigned int exynos_dp_get_plug_in_status(struct exynos_dp *dp_regs)
401 {
402 	unsigned int reg;
403 
404 	reg = readl(&dp_regs->sys_ctl3);
405 	if (reg & HPD_STATUS)
406 		return 0;
407 
408 	return -1;
409 }
410 
411 unsigned int exynos_dp_detect_hpd(struct exynos_dp *dp_regs)
412 {
413 	int timeout_loop = DP_TIMEOUT_LOOP_COUNT;
414 
415 	mdelay(2);
416 
417 	while (exynos_dp_get_plug_in_status(dp_regs) != 0) {
418 		if (timeout_loop == 0)
419 			return -EINVAL;
420 		mdelay(10);
421 		timeout_loop--;
422 	}
423 
424 	return EXYNOS_DP_SUCCESS;
425 }
426 
427 unsigned int exynos_dp_start_aux_transaction(struct exynos_dp *dp_regs)
428 {
429 	unsigned int reg;
430 	unsigned int ret = 0;
431 	unsigned int retry_cnt;
432 
433 	/* Enable AUX CH operation */
434 	reg = readl(&dp_regs->aux_ch_ctl2);
435 	reg |= AUX_EN;
436 	writel(reg, &dp_regs->aux_ch_ctl2);
437 
438 	retry_cnt = 10;
439 	while (retry_cnt) {
440 		reg = readl(&dp_regs->int_sta);
441 		if (!(reg & RPLY_RECEIV)) {
442 			if (retry_cnt == 0) {
443 				printf("DP Reply Timeout!!\n");
444 				ret = -EAGAIN;
445 				return ret;
446 			}
447 			mdelay(1);
448 			retry_cnt--;
449 		} else
450 			break;
451 	}
452 
453 	/* Clear interrupt source for AUX CH command reply */
454 	writel(reg, &dp_regs->int_sta);
455 
456 	/* Clear interrupt source for AUX CH access error */
457 	reg = readl(&dp_regs->int_sta);
458 	if (reg & AUX_ERR) {
459 		printf("DP Aux Access Error\n");
460 		writel(AUX_ERR, &dp_regs->int_sta);
461 		ret = -EAGAIN;
462 		return ret;
463 	}
464 
465 	/* Check AUX CH error access status */
466 	reg = readl(&dp_regs->aux_ch_sta);
467 	if ((reg & AUX_STATUS_MASK) != 0) {
468 		debug("DP AUX CH error happens: %x\n", reg & AUX_STATUS_MASK);
469 		ret = -EAGAIN;
470 		return ret;
471 	}
472 
473 	return EXYNOS_DP_SUCCESS;
474 }
475 
476 unsigned int exynos_dp_write_byte_to_dpcd(struct exynos_dp *dp_regs,
477 					  unsigned int reg_addr,
478 					  unsigned char data)
479 {
480 	unsigned int reg, ret;
481 
482 	/* Clear AUX CH data buffer */
483 	reg = BUF_CLR;
484 	writel(reg, &dp_regs->buffer_data_ctl);
485 
486 	/* Select DPCD device address */
487 	reg = AUX_ADDR_7_0(reg_addr);
488 	writel(reg, &dp_regs->aux_addr_7_0);
489 	reg = AUX_ADDR_15_8(reg_addr);
490 	writel(reg, &dp_regs->aux_addr_15_8);
491 	reg = AUX_ADDR_19_16(reg_addr);
492 	writel(reg, &dp_regs->aux_addr_19_16);
493 
494 	/* Write data buffer */
495 	reg = (unsigned int)data;
496 	writel(reg, &dp_regs->buf_data0);
497 
498 	/*
499 	 * Set DisplayPort transaction and write 1 byte
500 	 * If bit 3 is 1, DisplayPort transaction.
501 	 * If Bit 3 is 0, I2C transaction.
502 	 */
503 	reg = AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_WRITE;
504 	writel(reg, &dp_regs->aux_ch_ctl1);
505 
506 	/* Start AUX transaction */
507 	ret = exynos_dp_start_aux_transaction(dp_regs);
508 	if (ret != EXYNOS_DP_SUCCESS) {
509 		printf("DP Aux transaction failed\n");
510 		return ret;
511 	}
512 
513 	return ret;
514 }
515 
516 unsigned int exynos_dp_read_byte_from_dpcd(struct exynos_dp *dp_regs,
517 					   unsigned int reg_addr,
518 					   unsigned char *data)
519 {
520 	unsigned int reg;
521 	int retval;
522 
523 	/* Clear AUX CH data buffer */
524 	reg = BUF_CLR;
525 	writel(reg, &dp_regs->buffer_data_ctl);
526 
527 	/* Select DPCD device address */
528 	reg = AUX_ADDR_7_0(reg_addr);
529 	writel(reg, &dp_regs->aux_addr_7_0);
530 	reg = AUX_ADDR_15_8(reg_addr);
531 	writel(reg, &dp_regs->aux_addr_15_8);
532 	reg = AUX_ADDR_19_16(reg_addr);
533 	writel(reg, &dp_regs->aux_addr_19_16);
534 
535 	/*
536 	 * Set DisplayPort transaction and read 1 byte
537 	 * If bit 3 is 1, DisplayPort transaction.
538 	 * If Bit 3 is 0, I2C transaction.
539 	 */
540 	reg = AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_READ;
541 	writel(reg, &dp_regs->aux_ch_ctl1);
542 
543 	/* Start AUX transaction */
544 	retval = exynos_dp_start_aux_transaction(dp_regs);
545 	if (!retval)
546 		debug("DP Aux Transaction fail!\n");
547 
548 	/* Read data buffer */
549 	reg = readl(&dp_regs->buf_data0);
550 	*data = (unsigned char)(reg & 0xff);
551 
552 	return retval;
553 }
554 
555 unsigned int exynos_dp_write_bytes_to_dpcd(struct exynos_dp *dp_regs,
556 					   unsigned int reg_addr,
557 					   unsigned int count,
558 					   unsigned char data[])
559 {
560 	unsigned int reg;
561 	unsigned int start_offset;
562 	unsigned int cur_data_count;
563 	unsigned int cur_data_idx;
564 	unsigned int retry_cnt;
565 	unsigned int ret = 0;
566 
567 	/* Clear AUX CH data buffer */
568 	reg = BUF_CLR;
569 	writel(reg, &dp_regs->buffer_data_ctl);
570 
571 	start_offset = 0;
572 	while (start_offset < count) {
573 		/* Buffer size of AUX CH is 16 * 4bytes */
574 		if ((count - start_offset) > 16)
575 			cur_data_count = 16;
576 		else
577 			cur_data_count = count - start_offset;
578 
579 		retry_cnt = 5;
580 		while (retry_cnt) {
581 			/* Select DPCD device address */
582 			reg = AUX_ADDR_7_0(reg_addr + start_offset);
583 			writel(reg, &dp_regs->aux_addr_7_0);
584 			reg = AUX_ADDR_15_8(reg_addr + start_offset);
585 			writel(reg, &dp_regs->aux_addr_15_8);
586 			reg = AUX_ADDR_19_16(reg_addr + start_offset);
587 			writel(reg, &dp_regs->aux_addr_19_16);
588 
589 			for (cur_data_idx = 0; cur_data_idx < cur_data_count;
590 					cur_data_idx++) {
591 				reg = data[start_offset + cur_data_idx];
592 				writel(reg, (unsigned int)&dp_regs->buf_data0 +
593 						(4 * cur_data_idx));
594 			}
595 			/*
596 			* Set DisplayPort transaction and write
597 			* If bit 3 is 1, DisplayPort transaction.
598 			* If Bit 3 is 0, I2C transaction.
599 			*/
600 			reg = AUX_LENGTH(cur_data_count) |
601 				AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_WRITE;
602 			writel(reg, &dp_regs->aux_ch_ctl1);
603 
604 			/* Start AUX transaction */
605 			ret = exynos_dp_start_aux_transaction(dp_regs);
606 			if (ret != EXYNOS_DP_SUCCESS) {
607 				if (retry_cnt == 0) {
608 					printf("DP Aux Transaction failed\n");
609 					return ret;
610 				}
611 				retry_cnt--;
612 			} else
613 				break;
614 		}
615 		start_offset += cur_data_count;
616 	}
617 
618 	return ret;
619 }
620 
621 unsigned int exynos_dp_read_bytes_from_dpcd(struct exynos_dp *dp_regs,
622 					    unsigned int reg_addr,
623 					    unsigned int count,
624 					    unsigned char data[])
625 {
626 	unsigned int reg;
627 	unsigned int start_offset;
628 	unsigned int cur_data_count;
629 	unsigned int cur_data_idx;
630 	unsigned int retry_cnt;
631 	unsigned int ret = 0;
632 
633 	/* Clear AUX CH data buffer */
634 	reg = BUF_CLR;
635 	writel(reg, &dp_regs->buffer_data_ctl);
636 
637 	start_offset = 0;
638 	while (start_offset < count) {
639 		/* Buffer size of AUX CH is 16 * 4bytes */
640 		if ((count - start_offset) > 16)
641 			cur_data_count = 16;
642 		else
643 			cur_data_count = count - start_offset;
644 
645 		retry_cnt = 5;
646 		while (retry_cnt) {
647 			/* Select DPCD device address */
648 			reg = AUX_ADDR_7_0(reg_addr + start_offset);
649 			writel(reg, &dp_regs->aux_addr_7_0);
650 			reg = AUX_ADDR_15_8(reg_addr + start_offset);
651 			writel(reg, &dp_regs->aux_addr_15_8);
652 			reg = AUX_ADDR_19_16(reg_addr + start_offset);
653 			writel(reg, &dp_regs->aux_addr_19_16);
654 			/*
655 			 * Set DisplayPort transaction and read
656 			 * If bit 3 is 1, DisplayPort transaction.
657 			 * If Bit 3 is 0, I2C transaction.
658 			 */
659 			reg = AUX_LENGTH(cur_data_count) |
660 				AUX_TX_COMM_DP_TRANSACTION | AUX_TX_COMM_READ;
661 			writel(reg, &dp_regs->aux_ch_ctl1);
662 
663 			/* Start AUX transaction */
664 			ret = exynos_dp_start_aux_transaction(dp_regs);
665 			if (ret != EXYNOS_DP_SUCCESS) {
666 				if (retry_cnt == 0) {
667 					printf("DP Aux Transaction failed\n");
668 					return ret;
669 				}
670 				retry_cnt--;
671 			} else
672 				break;
673 		}
674 
675 		for (cur_data_idx = 0; cur_data_idx < cur_data_count;
676 				cur_data_idx++) {
677 			reg = readl((unsigned int)&dp_regs->buf_data0 +
678 					4 * cur_data_idx);
679 			data[start_offset + cur_data_idx] = (unsigned char)reg;
680 		}
681 
682 		start_offset += cur_data_count;
683 	}
684 
685 	return ret;
686 }
687 
688 int exynos_dp_select_i2c_device(struct exynos_dp *dp_regs,
689 				unsigned int device_addr, unsigned int reg_addr)
690 {
691 	unsigned int reg;
692 	int retval;
693 
694 	/* Set EDID device address */
695 	reg = device_addr;
696 	writel(reg, &dp_regs->aux_addr_7_0);
697 	writel(0x0, &dp_regs->aux_addr_15_8);
698 	writel(0x0, &dp_regs->aux_addr_19_16);
699 
700 	/* Set offset from base address of EDID device */
701 	writel(reg_addr, &dp_regs->buf_data0);
702 
703 	/*
704 	 * Set I2C transaction and write address
705 	 * If bit 3 is 1, DisplayPort transaction.
706 	 * If Bit 3 is 0, I2C transaction.
707 	 */
708 	reg = AUX_TX_COMM_I2C_TRANSACTION | AUX_TX_COMM_MOT |
709 		AUX_TX_COMM_WRITE;
710 	writel(reg, &dp_regs->aux_ch_ctl1);
711 
712 	/* Start AUX transaction */
713 	retval = exynos_dp_start_aux_transaction(dp_regs);
714 	if (retval != 0)
715 		printf("%s: DP Aux Transaction fail!\n", __func__);
716 
717 	return retval;
718 }
719 
720 int exynos_dp_read_byte_from_i2c(struct exynos_dp *dp_regs,
721 				 unsigned int device_addr,
722 				 unsigned int reg_addr, unsigned int *data)
723 {
724 	unsigned int reg;
725 	int i;
726 	int retval;
727 
728 	for (i = 0; i < 10; i++) {
729 		/* Clear AUX CH data buffer */
730 		reg = BUF_CLR;
731 		writel(reg, &dp_regs->buffer_data_ctl);
732 
733 		/* Select EDID device */
734 		retval = exynos_dp_select_i2c_device(dp_regs, device_addr,
735 						     reg_addr);
736 		if (retval != 0) {
737 			printf("DP Select EDID device fail. retry !\n");
738 			continue;
739 		}
740 
741 		/*
742 		 * Set I2C transaction and read data
743 		 * If bit 3 is 1, DisplayPort transaction.
744 		 * If Bit 3 is 0, I2C transaction.
745 		 */
746 		reg = AUX_TX_COMM_I2C_TRANSACTION |
747 			AUX_TX_COMM_READ;
748 		writel(reg, &dp_regs->aux_ch_ctl1);
749 
750 		/* Start AUX transaction */
751 		retval = exynos_dp_start_aux_transaction(dp_regs);
752 		if (retval != EXYNOS_DP_SUCCESS)
753 			printf("%s: DP Aux Transaction fail!\n", __func__);
754 	}
755 
756 	/* Read data */
757 	if (retval == 0)
758 		*data = readl(&dp_regs->buf_data0);
759 
760 	return retval;
761 }
762 
763 int exynos_dp_read_bytes_from_i2c(struct exynos_dp *dp_regs,
764 				  unsigned int device_addr,
765 				  unsigned int reg_addr, unsigned int count,
766 				  unsigned char edid[])
767 {
768 	unsigned int reg;
769 	unsigned int i, j;
770 	unsigned int cur_data_idx;
771 	unsigned int defer = 0;
772 	int retval = 0;
773 
774 	for (i = 0; i < count; i += 16) { /* use 16 burst */
775 		for (j = 0; j < 100; j++) {
776 			/* Clear AUX CH data buffer */
777 			reg = BUF_CLR;
778 			writel(reg, &dp_regs->buffer_data_ctl);
779 
780 			/* Set normal AUX CH command */
781 			reg = readl(&dp_regs->aux_ch_ctl2);
782 			reg &= ~ADDR_ONLY;
783 			writel(reg, &dp_regs->aux_ch_ctl2);
784 
785 			/*
786 			 * If Rx sends defer, Tx sends only reads
787 			 * request without sending addres
788 			 */
789 			if (!defer)
790 				retval = exynos_dp_select_i2c_device(
791 					dp_regs, device_addr, reg_addr + i);
792 			else
793 				defer = 0;
794 
795 			if (retval == EXYNOS_DP_SUCCESS) {
796 				/*
797 				 * Set I2C transaction and write data
798 				 * If bit 3 is 1, DisplayPort transaction.
799 				 * If Bit 3 is 0, I2C transaction.
800 				 */
801 				reg = AUX_LENGTH(16) |
802 					AUX_TX_COMM_I2C_TRANSACTION |
803 					AUX_TX_COMM_READ;
804 				writel(reg, &dp_regs->aux_ch_ctl1);
805 
806 				/* Start AUX transaction */
807 				retval = exynos_dp_start_aux_transaction(
808 							dp_regs);
809 				if (retval == 0)
810 					break;
811 				else
812 					printf("DP Aux Transaction fail!\n");
813 			}
814 			/* Check if Rx sends defer */
815 			reg = readl(&dp_regs->aux_rx_comm);
816 			if (reg == AUX_RX_COMM_AUX_DEFER ||
817 				reg == AUX_RX_COMM_I2C_DEFER) {
818 				printf("DP Defer: %d\n", reg);
819 				defer = 1;
820 			}
821 		}
822 
823 		for (cur_data_idx = 0; cur_data_idx < 16; cur_data_idx++) {
824 			reg = readl((unsigned int)&dp_regs->buf_data0
825 						 + 4 * cur_data_idx);
826 			edid[i + cur_data_idx] = (unsigned char)reg;
827 		}
828 	}
829 
830 	return retval;
831 }
832 
833 void exynos_dp_reset_macro(struct exynos_dp *dp_regs)
834 {
835 	unsigned int reg;
836 
837 	reg = readl(&dp_regs->phy_test);
838 	reg |= MACRO_RST;
839 	writel(reg, &dp_regs->phy_test);
840 
841 	/* 10 us is the minimum Macro reset time. */
842 	mdelay(1);
843 
844 	reg &= ~MACRO_RST;
845 	writel(reg, &dp_regs->phy_test);
846 }
847 
848 void exynos_dp_set_link_bandwidth(struct exynos_dp *dp_regs,
849 				  unsigned char bwtype)
850 {
851 	unsigned int reg;
852 
853 	reg = (unsigned int)bwtype;
854 
855 	 /* Set bandwidth to 2.7G or 1.62G */
856 	if ((bwtype == DP_LANE_BW_1_62) || (bwtype == DP_LANE_BW_2_70))
857 		writel(reg, &dp_regs->link_bw_set);
858 }
859 
860 unsigned char exynos_dp_get_link_bandwidth(struct exynos_dp *dp_regs)
861 {
862 	unsigned char ret;
863 	unsigned int reg;
864 
865 	reg = readl(&dp_regs->link_bw_set);
866 	ret = (unsigned char)reg;
867 
868 	return ret;
869 }
870 
871 void exynos_dp_set_lane_count(struct exynos_dp *dp_regs, unsigned char count)
872 {
873 	unsigned int reg;
874 
875 	reg = (unsigned int)count;
876 
877 	if ((count == DP_LANE_CNT_1) || (count == DP_LANE_CNT_2) ||
878 			(count == DP_LANE_CNT_4))
879 		writel(reg, &dp_regs->lane_count_set);
880 }
881 
882 unsigned int exynos_dp_get_lane_count(struct exynos_dp *dp_regs)
883 {
884 	unsigned int reg;
885 
886 	reg = readl(&dp_regs->lane_count_set);
887 
888 	return reg;
889 }
890 
891 unsigned char exynos_dp_get_lanex_pre_emphasis(struct exynos_dp *dp_regs,
892 					       unsigned char lanecnt)
893 {
894 	unsigned int reg_list[DP_LANE_CNT_4] = {
895 		(unsigned int)&dp_regs->ln0_link_training_ctl,
896 		(unsigned int)&dp_regs->ln1_link_training_ctl,
897 		(unsigned int)&dp_regs->ln2_link_training_ctl,
898 		(unsigned int)&dp_regs->ln3_link_training_ctl,
899 	};
900 
901 	return readl(reg_list[lanecnt]);
902 }
903 
904 void exynos_dp_set_lanex_pre_emphasis(struct exynos_dp *dp_regs,
905 				      unsigned char request_val,
906 				      unsigned char lanecnt)
907 {
908 	unsigned int reg_list[DP_LANE_CNT_4] = {
909 		(unsigned int)&dp_regs->ln0_link_training_ctl,
910 		(unsigned int)&dp_regs->ln1_link_training_ctl,
911 		(unsigned int)&dp_regs->ln2_link_training_ctl,
912 		(unsigned int)&dp_regs->ln3_link_training_ctl,
913 	};
914 
915 	writel(request_val, reg_list[lanecnt]);
916 }
917 
918 void exynos_dp_set_lane_pre_emphasis(struct exynos_dp *dp_regs,
919 				     unsigned int level, unsigned char lanecnt)
920 {
921 	unsigned char i;
922 	unsigned int reg;
923 	unsigned int reg_list[DP_LANE_CNT_4] = {
924 		(unsigned int)&dp_regs->ln0_link_training_ctl,
925 		(unsigned int)&dp_regs->ln1_link_training_ctl,
926 		(unsigned int)&dp_regs->ln2_link_training_ctl,
927 		(unsigned int)&dp_regs->ln3_link_training_ctl,
928 	};
929 	unsigned int reg_shift[DP_LANE_CNT_4] = {
930 		PRE_EMPHASIS_SET_0_SHIFT,
931 		PRE_EMPHASIS_SET_1_SHIFT,
932 		PRE_EMPHASIS_SET_2_SHIFT,
933 		PRE_EMPHASIS_SET_3_SHIFT
934 	};
935 
936 	for (i = 0; i < lanecnt; i++) {
937 		reg = level << reg_shift[i];
938 		writel(reg, reg_list[i]);
939 	}
940 }
941 
942 void exynos_dp_set_training_pattern(struct exynos_dp *dp_regs,
943 				    unsigned int pattern)
944 {
945 	unsigned int reg = 0;
946 
947 	switch (pattern) {
948 	case PRBS7:
949 		reg = SCRAMBLING_ENABLE | LINK_QUAL_PATTERN_SET_PRBS7;
950 		break;
951 	case D10_2:
952 		reg = SCRAMBLING_ENABLE | LINK_QUAL_PATTERN_SET_D10_2;
953 		break;
954 	case TRAINING_PTN1:
955 		reg = SCRAMBLING_DISABLE | SW_TRAINING_PATTERN_SET_PTN1;
956 		break;
957 	case TRAINING_PTN2:
958 		reg = SCRAMBLING_DISABLE | SW_TRAINING_PATTERN_SET_PTN2;
959 		break;
960 	case DP_NONE:
961 		reg = SCRAMBLING_ENABLE | LINK_QUAL_PATTERN_SET_DISABLE |
962 			SW_TRAINING_PATTERN_SET_NORMAL;
963 		break;
964 	default:
965 		break;
966 	}
967 
968 	writel(reg, &dp_regs->training_ptn_set);
969 }
970 
971 void exynos_dp_enable_enhanced_mode(struct exynos_dp *dp_regs,
972 				    unsigned char enable)
973 {
974 	unsigned int reg;
975 
976 	reg = readl(&dp_regs->sys_ctl4);
977 	reg &= ~ENHANCED;
978 
979 	if (enable)
980 		reg |= ENHANCED;
981 
982 	writel(reg, &dp_regs->sys_ctl4);
983 }
984 
985 void exynos_dp_enable_scrambling(struct exynos_dp *dp_regs, unsigned int enable)
986 {
987 	unsigned int reg;
988 
989 	reg = readl(&dp_regs->training_ptn_set);
990 	reg &= ~(SCRAMBLING_DISABLE);
991 
992 	if (!enable)
993 		reg |= SCRAMBLING_DISABLE;
994 
995 	writel(reg, &dp_regs->training_ptn_set);
996 }
997 
998 int exynos_dp_init_video(struct exynos_dp *dp_regs)
999 {
1000 	unsigned int reg;
1001 
1002 	/* Clear VID_CLK_CHG[1] and VID_FORMAT_CHG[3] and VSYNC_DET[7] */
1003 	reg = VSYNC_DET | VID_FORMAT_CHG | VID_CLK_CHG;
1004 	writel(reg, &dp_regs->common_int_sta1);
1005 
1006 	/* I_STRM__CLK detect : DE_CTL : Auto detect */
1007 	reg &= ~DET_CTRL;
1008 	writel(reg, &dp_regs->sys_ctl1);
1009 
1010 	return 0;
1011 }
1012 
1013 void exynos_dp_config_video_slave_mode(struct exynos_dp *dp_regs,
1014 				       struct edp_video_info *video_info)
1015 {
1016 	unsigned int reg;
1017 
1018 	/* Video Slave mode setting */
1019 	reg = readl(&dp_regs->func_en1);
1020 	reg &= ~(MASTER_VID_FUNC_EN_N|SLAVE_VID_FUNC_EN_N);
1021 	reg |= MASTER_VID_FUNC_EN_N;
1022 	writel(reg, &dp_regs->func_en1);
1023 
1024 	/* Configure Interlaced for slave mode video */
1025 	reg = readl(&dp_regs->video_ctl10);
1026 	reg &= ~INTERACE_SCAN_CFG;
1027 	reg |= (video_info->interlaced << INTERACE_SCAN_CFG_SHIFT);
1028 	writel(reg, &dp_regs->video_ctl10);
1029 
1030 	/* Configure V sync polarity for slave mode video */
1031 	reg = readl(&dp_regs->video_ctl10);
1032 	reg &= ~VSYNC_POLARITY_CFG;
1033 	reg |= (video_info->v_sync_polarity << V_S_POLARITY_CFG_SHIFT);
1034 	writel(reg, &dp_regs->video_ctl10);
1035 
1036 	/* Configure H sync polarity for slave mode video */
1037 	reg = readl(&dp_regs->video_ctl10);
1038 	reg &= ~HSYNC_POLARITY_CFG;
1039 	reg |= (video_info->h_sync_polarity << H_S_POLARITY_CFG_SHIFT);
1040 	writel(reg, &dp_regs->video_ctl10);
1041 
1042 	/* Set video mode to slave mode */
1043 	reg = AUDIO_MODE_SPDIF_MODE | VIDEO_MODE_SLAVE_MODE;
1044 	writel(reg, &dp_regs->soc_general_ctl);
1045 }
1046 
1047 void exynos_dp_set_video_color_format(struct exynos_dp *dp_regs,
1048 				      struct edp_video_info *video_info)
1049 {
1050 	unsigned int reg;
1051 
1052 	/* Configure the input color depth, color space, dynamic range */
1053 	reg = (video_info->dynamic_range << IN_D_RANGE_SHIFT) |
1054 		(video_info->color_depth << IN_BPC_SHIFT) |
1055 		(video_info->color_space << IN_COLOR_F_SHIFT);
1056 	writel(reg, &dp_regs->video_ctl2);
1057 
1058 	/* Set Input Color YCbCr Coefficients to ITU601 or ITU709 */
1059 	reg = readl(&dp_regs->video_ctl3);
1060 	reg &= ~IN_YC_COEFFI_MASK;
1061 	if (video_info->ycbcr_coeff)
1062 		reg |= IN_YC_COEFFI_ITU709;
1063 	else
1064 		reg |= IN_YC_COEFFI_ITU601;
1065 	writel(reg, &dp_regs->video_ctl3);
1066 }
1067 
1068 int exynos_dp_config_video_bist(struct exynos_dp *dp_regs,
1069 				struct exynos_dp_priv *priv)
1070 {
1071 	unsigned int reg;
1072 	unsigned int bist_type = 0;
1073 	struct edp_video_info video_info = priv->video_info;
1074 
1075 	/* For master mode, you don't need to set the video format */
1076 	if (video_info.master_mode == 0) {
1077 		writel(TOTAL_LINE_CFG_L(priv->disp_info.v_total),
1078 		       &dp_regs->total_ln_cfg_l);
1079 		writel(TOTAL_LINE_CFG_H(priv->disp_info.v_total),
1080 		       &dp_regs->total_ln_cfg_h);
1081 		writel(ACTIVE_LINE_CFG_L(priv->disp_info.v_res),
1082 		       &dp_regs->active_ln_cfg_l);
1083 		writel(ACTIVE_LINE_CFG_H(priv->disp_info.v_res),
1084 		       &dp_regs->active_ln_cfg_h);
1085 		writel(priv->disp_info.v_sync_width, &dp_regs->vsw_cfg);
1086 		writel(priv->disp_info.v_back_porch, &dp_regs->vbp_cfg);
1087 		writel(priv->disp_info.v_front_porch, &dp_regs->vfp_cfg);
1088 
1089 		writel(TOTAL_PIXEL_CFG_L(priv->disp_info.h_total),
1090 		       &dp_regs->total_pix_cfg_l);
1091 		writel(TOTAL_PIXEL_CFG_H(priv->disp_info.h_total),
1092 		       &dp_regs->total_pix_cfg_h);
1093 		writel(ACTIVE_PIXEL_CFG_L(priv->disp_info.h_res),
1094 		       &dp_regs->active_pix_cfg_l);
1095 		writel(ACTIVE_PIXEL_CFG_H(priv->disp_info.h_res),
1096 		       &dp_regs->active_pix_cfg_h);
1097 		writel(H_F_PORCH_CFG_L(priv->disp_info.h_front_porch),
1098 		       &dp_regs->hfp_cfg_l);
1099 		writel(H_F_PORCH_CFG_H(priv->disp_info.h_front_porch),
1100 		       &dp_regs->hfp_cfg_h);
1101 		writel(H_SYNC_PORCH_CFG_L(priv->disp_info.h_sync_width),
1102 		       &dp_regs->hsw_cfg_l);
1103 		writel(H_SYNC_PORCH_CFG_H(priv->disp_info.h_sync_width),
1104 		       &dp_regs->hsw_cfg_h);
1105 		writel(H_B_PORCH_CFG_L(priv->disp_info.h_back_porch),
1106 		       &dp_regs->hbp_cfg_l);
1107 		writel(H_B_PORCH_CFG_H(priv->disp_info.h_back_porch),
1108 		       &dp_regs->hbp_cfg_h);
1109 
1110 		/*
1111 		 * Set SLAVE_I_SCAN_CFG[2], VSYNC_P_CFG[1],
1112 		 * HSYNC_P_CFG[0] properly
1113 		 */
1114 		reg = (video_info.interlaced << INTERACE_SCAN_CFG_SHIFT |
1115 			video_info.v_sync_polarity << V_S_POLARITY_CFG_SHIFT |
1116 			video_info.h_sync_polarity << H_S_POLARITY_CFG_SHIFT);
1117 		writel(reg, &dp_regs->video_ctl10);
1118 	}
1119 
1120 	/* BIST color bar width set--set to each bar is 32 pixel width */
1121 	switch (video_info.bist_pattern) {
1122 	case COLORBAR_32:
1123 		bist_type = BIST_WIDTH_BAR_32_PIXEL |
1124 			  BIST_TYPE_COLOR_BAR;
1125 		break;
1126 	case COLORBAR_64:
1127 		bist_type = BIST_WIDTH_BAR_64_PIXEL |
1128 			  BIST_TYPE_COLOR_BAR;
1129 		break;
1130 	case WHITE_GRAY_BALCKBAR_32:
1131 		bist_type = BIST_WIDTH_BAR_32_PIXEL |
1132 			  BIST_TYPE_WHITE_GRAY_BLACK_BAR;
1133 		break;
1134 	case WHITE_GRAY_BALCKBAR_64:
1135 		bist_type = BIST_WIDTH_BAR_64_PIXEL |
1136 			  BIST_TYPE_WHITE_GRAY_BLACK_BAR;
1137 		break;
1138 	case MOBILE_WHITEBAR_32:
1139 		bist_type = BIST_WIDTH_BAR_32_PIXEL |
1140 			  BIST_TYPE_MOBILE_WHITE_BAR;
1141 		break;
1142 	case MOBILE_WHITEBAR_64:
1143 		bist_type = BIST_WIDTH_BAR_64_PIXEL |
1144 			  BIST_TYPE_MOBILE_WHITE_BAR;
1145 		break;
1146 	default:
1147 		return -1;
1148 	}
1149 
1150 	reg = bist_type;
1151 	writel(reg, &dp_regs->video_ctl4);
1152 
1153 	return 0;
1154 }
1155 
1156 unsigned int exynos_dp_is_slave_video_stream_clock_on(struct exynos_dp *dp_regs)
1157 {
1158 	unsigned int reg;
1159 
1160 	/* Update Video stream clk detect status */
1161 	reg = readl(&dp_regs->sys_ctl1);
1162 	writel(reg, &dp_regs->sys_ctl1);
1163 
1164 	reg = readl(&dp_regs->sys_ctl1);
1165 
1166 	if (!(reg & DET_STA)) {
1167 		debug("DP Input stream clock not detected.\n");
1168 		return -EIO;
1169 	}
1170 
1171 	return EXYNOS_DP_SUCCESS;
1172 }
1173 
1174 void exynos_dp_set_video_cr_mn(struct exynos_dp *dp_regs, unsigned int type,
1175 			       unsigned int m_value, unsigned int n_value)
1176 {
1177 	unsigned int reg;
1178 
1179 	if (type == REGISTER_M) {
1180 		reg = readl(&dp_regs->sys_ctl4);
1181 		reg |= FIX_M_VID;
1182 		writel(reg, &dp_regs->sys_ctl4);
1183 		reg = M_VID0_CFG(m_value);
1184 		writel(reg, &dp_regs->m_vid0);
1185 		reg = M_VID1_CFG(m_value);
1186 		writel(reg, &dp_regs->m_vid1);
1187 		reg = M_VID2_CFG(m_value);
1188 		writel(reg, &dp_regs->m_vid2);
1189 
1190 		reg = N_VID0_CFG(n_value);
1191 		writel(reg, &dp_regs->n_vid0);
1192 		reg = N_VID1_CFG(n_value);
1193 		writel(reg, &dp_regs->n_vid1);
1194 		reg = N_VID2_CFG(n_value);
1195 		writel(reg, &dp_regs->n_vid2);
1196 	} else  {
1197 		reg = readl(&dp_regs->sys_ctl4);
1198 		reg &= ~FIX_M_VID;
1199 		writel(reg, &dp_regs->sys_ctl4);
1200 	}
1201 }
1202 
1203 void exynos_dp_set_video_timing_mode(struct exynos_dp *dp_regs,
1204 				     unsigned int type)
1205 {
1206 	unsigned int reg;
1207 
1208 	reg = readl(&dp_regs->video_ctl10);
1209 	reg &= ~FORMAT_SEL;
1210 
1211 	if (type != VIDEO_TIMING_FROM_CAPTURE)
1212 		reg |= FORMAT_SEL;
1213 
1214 	writel(reg, &dp_regs->video_ctl10);
1215 }
1216 
1217 void exynos_dp_enable_video_master(struct exynos_dp *dp_regs,
1218 				   unsigned int enable)
1219 {
1220 	unsigned int reg;
1221 
1222 	reg = readl(&dp_regs->soc_general_ctl);
1223 	if (enable) {
1224 		reg &= ~VIDEO_MODE_MASK;
1225 		reg |= VIDEO_MASTER_MODE_EN | VIDEO_MODE_MASTER_MODE;
1226 	} else {
1227 		reg &= ~VIDEO_MODE_MASK;
1228 		reg |= VIDEO_MODE_SLAVE_MODE;
1229 	}
1230 
1231 	writel(reg, &dp_regs->soc_general_ctl);
1232 }
1233 
1234 void exynos_dp_start_video(struct exynos_dp *dp_regs)
1235 {
1236 	unsigned int reg;
1237 
1238 	/* Enable Video input and disable Mute */
1239 	reg = readl(&dp_regs->video_ctl1);
1240 	reg |= VIDEO_EN;
1241 	writel(reg, &dp_regs->video_ctl1);
1242 }
1243 
1244 unsigned int exynos_dp_is_video_stream_on(struct exynos_dp *dp_regs)
1245 {
1246 	unsigned int reg;
1247 
1248 	/* Update STRM_VALID */
1249 	reg = readl(&dp_regs->sys_ctl3);
1250 	writel(reg, &dp_regs->sys_ctl3);
1251 
1252 	reg = readl(&dp_regs->sys_ctl3);
1253 	if (!(reg & STRM_VALID))
1254 		return -EIO;
1255 
1256 	return EXYNOS_DP_SUCCESS;
1257 }
1258