xref: /openbmc/linux/drivers/gpu/drm/tegra/dpaux.c (revision be58f710) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2013 NVIDIA Corporation
4  */
5 
6 #include <linux/clk.h>
7 #include <linux/delay.h>
8 #include <linux/interrupt.h>
9 #include <linux/io.h>
10 #include <linux/module.h>
11 #include <linux/of_device.h>
12 #include <linux/pinctrl/pinconf-generic.h>
13 #include <linux/pinctrl/pinctrl.h>
14 #include <linux/pinctrl/pinmux.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm_runtime.h>
17 #include <linux/regulator/consumer.h>
18 #include <linux/reset.h>
19 #include <linux/workqueue.h>
20 
21 #include <drm/drm_dp_helper.h>
22 #include <drm/drm_panel.h>
23 
24 #include "dp.h"
25 #include "dpaux.h"
26 #include "drm.h"
27 #include "trace.h"
28 
29 static DEFINE_MUTEX(dpaux_lock);
30 static LIST_HEAD(dpaux_list);
31 
32 struct tegra_dpaux_soc {
33 	unsigned int cmh;
34 	unsigned int drvz;
35 	unsigned int drvi;
36 };
37 
38 struct tegra_dpaux {
39 	struct drm_dp_aux aux;
40 	struct device *dev;
41 
42 	const struct tegra_dpaux_soc *soc;
43 
44 	void __iomem *regs;
45 	int irq;
46 
47 	struct tegra_output *output;
48 
49 	struct reset_control *rst;
50 	struct clk *clk_parent;
51 	struct clk *clk;
52 
53 	struct regulator *vdd;
54 
55 	struct completion complete;
56 	struct work_struct work;
57 	struct list_head list;
58 
59 #ifdef CONFIG_GENERIC_PINCONF
60 	struct pinctrl_dev *pinctrl;
61 	struct pinctrl_desc desc;
62 #endif
63 };
64 
65 static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)
66 {
67 	return container_of(aux, struct tegra_dpaux, aux);
68 }
69 
70 static inline struct tegra_dpaux *work_to_dpaux(struct work_struct *work)
71 {
72 	return container_of(work, struct tegra_dpaux, work);
73 }
74 
75 static inline u32 tegra_dpaux_readl(struct tegra_dpaux *dpaux,
76 				    unsigned int offset)
77 {
78 	u32 value = readl(dpaux->regs + (offset << 2));
79 
80 	trace_dpaux_readl(dpaux->dev, offset, value);
81 
82 	return value;
83 }
84 
85 static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,
86 				      u32 value, unsigned int offset)
87 {
88 	trace_dpaux_writel(dpaux->dev, offset, value);
89 	writel(value, dpaux->regs + (offset << 2));
90 }
91 
92 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
93 				   size_t size)
94 {
95 	size_t i, j;
96 
97 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
98 		size_t num = min_t(size_t, size - i * 4, 4);
99 		u32 value = 0;
100 
101 		for (j = 0; j < num; j++)
102 			value |= buffer[i * 4 + j] << (j * 8);
103 
104 		tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
105 	}
106 }
107 
108 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
109 				  size_t size)
110 {
111 	size_t i, j;
112 
113 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
114 		size_t num = min_t(size_t, size - i * 4, 4);
115 		u32 value;
116 
117 		value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
118 
119 		for (j = 0; j < num; j++)
120 			buffer[i * 4 + j] = value >> (j * 8);
121 	}
122 }
123 
124 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
125 				    struct drm_dp_aux_msg *msg)
126 {
127 	unsigned long timeout = msecs_to_jiffies(250);
128 	struct tegra_dpaux *dpaux = to_dpaux(aux);
129 	unsigned long status;
130 	ssize_t ret = 0;
131 	u8 reply = 0;
132 	u32 value;
133 
134 	/* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
135 	if (msg->size > 16)
136 		return -EINVAL;
137 
138 	/*
139 	 * Allow zero-sized messages only for I2C, in which case they specify
140 	 * address-only transactions.
141 	 */
142 	if (msg->size < 1) {
143 		switch (msg->request & ~DP_AUX_I2C_MOT) {
144 		case DP_AUX_I2C_WRITE_STATUS_UPDATE:
145 		case DP_AUX_I2C_WRITE:
146 		case DP_AUX_I2C_READ:
147 			value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;
148 			break;
149 
150 		default:
151 			return -EINVAL;
152 		}
153 	} else {
154 		/* For non-zero-sized messages, set the CMDLEN field. */
155 		value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
156 	}
157 
158 	switch (msg->request & ~DP_AUX_I2C_MOT) {
159 	case DP_AUX_I2C_WRITE:
160 		if (msg->request & DP_AUX_I2C_MOT)
161 			value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;
162 		else
163 			value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;
164 
165 		break;
166 
167 	case DP_AUX_I2C_READ:
168 		if (msg->request & DP_AUX_I2C_MOT)
169 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;
170 		else
171 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;
172 
173 		break;
174 
175 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
176 		if (msg->request & DP_AUX_I2C_MOT)
177 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;
178 		else
179 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;
180 
181 		break;
182 
183 	case DP_AUX_NATIVE_WRITE:
184 		value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;
185 		break;
186 
187 	case DP_AUX_NATIVE_READ:
188 		value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;
189 		break;
190 
191 	default:
192 		return -EINVAL;
193 	}
194 
195 	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
196 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
197 
198 	if ((msg->request & DP_AUX_I2C_READ) == 0) {
199 		tegra_dpaux_write_fifo(dpaux, msg->buffer, msg->size);
200 		ret = msg->size;
201 	}
202 
203 	/* start transaction */
204 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXCTL);
205 	value |= DPAUX_DP_AUXCTL_TRANSACTREQ;
206 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
207 
208 	status = wait_for_completion_timeout(&dpaux->complete, timeout);
209 	if (!status)
210 		return -ETIMEDOUT;
211 
212 	/* read status and clear errors */
213 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
214 	tegra_dpaux_writel(dpaux, 0xf00, DPAUX_DP_AUXSTAT);
215 
216 	if (value & DPAUX_DP_AUXSTAT_TIMEOUT_ERROR)
217 		return -ETIMEDOUT;
218 
219 	if ((value & DPAUX_DP_AUXSTAT_RX_ERROR) ||
220 	    (value & DPAUX_DP_AUXSTAT_SINKSTAT_ERROR) ||
221 	    (value & DPAUX_DP_AUXSTAT_NO_STOP_ERROR))
222 		return -EIO;
223 
224 	switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) {
225 	case 0x00:
226 		reply = DP_AUX_NATIVE_REPLY_ACK;
227 		break;
228 
229 	case 0x01:
230 		reply = DP_AUX_NATIVE_REPLY_NACK;
231 		break;
232 
233 	case 0x02:
234 		reply = DP_AUX_NATIVE_REPLY_DEFER;
235 		break;
236 
237 	case 0x04:
238 		reply = DP_AUX_I2C_REPLY_NACK;
239 		break;
240 
241 	case 0x08:
242 		reply = DP_AUX_I2C_REPLY_DEFER;
243 		break;
244 	}
245 
246 	if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {
247 		if (msg->request & DP_AUX_I2C_READ) {
248 			size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;
249 
250 			/*
251 			 * There might be a smarter way to do this, but since
252 			 * the DP helpers will already retry transactions for
253 			 * an -EBUSY return value, simply reuse that instead.
254 			 */
255 			if (count != msg->size) {
256 				ret = -EBUSY;
257 				goto out;
258 			}
259 
260 			tegra_dpaux_read_fifo(dpaux, msg->buffer, count);
261 			ret = count;
262 		}
263 	}
264 
265 	msg->reply = reply;
266 
267 out:
268 	return ret;
269 }
270 
271 static void tegra_dpaux_hotplug(struct work_struct *work)
272 {
273 	struct tegra_dpaux *dpaux = work_to_dpaux(work);
274 
275 	if (dpaux->output)
276 		drm_helper_hpd_irq_event(dpaux->output->connector.dev);
277 }
278 
279 static irqreturn_t tegra_dpaux_irq(int irq, void *data)
280 {
281 	struct tegra_dpaux *dpaux = data;
282 	irqreturn_t ret = IRQ_HANDLED;
283 	u32 value;
284 
285 	/* clear interrupts */
286 	value = tegra_dpaux_readl(dpaux, DPAUX_INTR_AUX);
287 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
288 
289 	if (value & (DPAUX_INTR_PLUG_EVENT | DPAUX_INTR_UNPLUG_EVENT))
290 		schedule_work(&dpaux->work);
291 
292 	if (value & DPAUX_INTR_IRQ_EVENT) {
293 		/* TODO: handle this */
294 	}
295 
296 	if (value & DPAUX_INTR_AUX_DONE)
297 		complete(&dpaux->complete);
298 
299 	return ret;
300 }
301 
302 enum tegra_dpaux_functions {
303 	DPAUX_PADCTL_FUNC_AUX,
304 	DPAUX_PADCTL_FUNC_I2C,
305 	DPAUX_PADCTL_FUNC_OFF,
306 };
307 
308 static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
309 {
310 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
311 
312 	value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
313 
314 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
315 }
316 
317 static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)
318 {
319 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
320 
321 	value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
322 
323 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
324 }
325 
326 static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
327 {
328 	u32 value;
329 
330 	switch (function) {
331 	case DPAUX_PADCTL_FUNC_AUX:
332 		value = DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
333 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
334 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
335 			DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
336 			DPAUX_HYBRID_PADCTL_MODE_AUX;
337 		break;
338 
339 	case DPAUX_PADCTL_FUNC_I2C:
340 		value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
341 			DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
342 			DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
343 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
344 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
345 			DPAUX_HYBRID_PADCTL_MODE_I2C;
346 		break;
347 
348 	case DPAUX_PADCTL_FUNC_OFF:
349 		tegra_dpaux_pad_power_down(dpaux);
350 		return 0;
351 
352 	default:
353 		return -ENOTSUPP;
354 	}
355 
356 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
357 	tegra_dpaux_pad_power_up(dpaux);
358 
359 	return 0;
360 }
361 
362 #ifdef CONFIG_GENERIC_PINCONF
363 static const struct pinctrl_pin_desc tegra_dpaux_pins[] = {
364 	PINCTRL_PIN(0, "DP_AUX_CHx_P"),
365 	PINCTRL_PIN(1, "DP_AUX_CHx_N"),
366 };
367 
368 static const unsigned tegra_dpaux_pin_numbers[] = { 0, 1 };
369 
370 static const char * const tegra_dpaux_groups[] = {
371 	"dpaux-io",
372 };
373 
374 static const char * const tegra_dpaux_functions[] = {
375 	"aux",
376 	"i2c",
377 	"off",
378 };
379 
380 static int tegra_dpaux_get_groups_count(struct pinctrl_dev *pinctrl)
381 {
382 	return ARRAY_SIZE(tegra_dpaux_groups);
383 }
384 
385 static const char *tegra_dpaux_get_group_name(struct pinctrl_dev *pinctrl,
386 					      unsigned int group)
387 {
388 	return tegra_dpaux_groups[group];
389 }
390 
391 static int tegra_dpaux_get_group_pins(struct pinctrl_dev *pinctrl,
392 				      unsigned group, const unsigned **pins,
393 				      unsigned *num_pins)
394 {
395 	*pins = tegra_dpaux_pin_numbers;
396 	*num_pins = ARRAY_SIZE(tegra_dpaux_pin_numbers);
397 
398 	return 0;
399 }
400 
401 static const struct pinctrl_ops tegra_dpaux_pinctrl_ops = {
402 	.get_groups_count = tegra_dpaux_get_groups_count,
403 	.get_group_name = tegra_dpaux_get_group_name,
404 	.get_group_pins = tegra_dpaux_get_group_pins,
405 	.dt_node_to_map = pinconf_generic_dt_node_to_map_group,
406 	.dt_free_map = pinconf_generic_dt_free_map,
407 };
408 
409 static int tegra_dpaux_get_functions_count(struct pinctrl_dev *pinctrl)
410 {
411 	return ARRAY_SIZE(tegra_dpaux_functions);
412 }
413 
414 static const char *tegra_dpaux_get_function_name(struct pinctrl_dev *pinctrl,
415 						 unsigned int function)
416 {
417 	return tegra_dpaux_functions[function];
418 }
419 
420 static int tegra_dpaux_get_function_groups(struct pinctrl_dev *pinctrl,
421 					   unsigned int function,
422 					   const char * const **groups,
423 					   unsigned * const num_groups)
424 {
425 	*num_groups = ARRAY_SIZE(tegra_dpaux_groups);
426 	*groups = tegra_dpaux_groups;
427 
428 	return 0;
429 }
430 
431 static int tegra_dpaux_set_mux(struct pinctrl_dev *pinctrl,
432 			       unsigned int function, unsigned int group)
433 {
434 	struct tegra_dpaux *dpaux = pinctrl_dev_get_drvdata(pinctrl);
435 
436 	return tegra_dpaux_pad_config(dpaux, function);
437 }
438 
439 static const struct pinmux_ops tegra_dpaux_pinmux_ops = {
440 	.get_functions_count = tegra_dpaux_get_functions_count,
441 	.get_function_name = tegra_dpaux_get_function_name,
442 	.get_function_groups = tegra_dpaux_get_function_groups,
443 	.set_mux = tegra_dpaux_set_mux,
444 };
445 #endif
446 
447 static int tegra_dpaux_probe(struct platform_device *pdev)
448 {
449 	struct tegra_dpaux *dpaux;
450 	struct resource *regs;
451 	u32 value;
452 	int err;
453 
454 	dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);
455 	if (!dpaux)
456 		return -ENOMEM;
457 
458 	dpaux->soc = of_device_get_match_data(&pdev->dev);
459 	INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);
460 	init_completion(&dpaux->complete);
461 	INIT_LIST_HEAD(&dpaux->list);
462 	dpaux->dev = &pdev->dev;
463 
464 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
465 	dpaux->regs = devm_ioremap_resource(&pdev->dev, regs);
466 	if (IS_ERR(dpaux->regs))
467 		return PTR_ERR(dpaux->regs);
468 
469 	dpaux->irq = platform_get_irq(pdev, 0);
470 	if (dpaux->irq < 0)
471 		return -ENXIO;
472 
473 	if (!pdev->dev.pm_domain) {
474 		dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");
475 		if (IS_ERR(dpaux->rst)) {
476 			dev_err(&pdev->dev,
477 				"failed to get reset control: %ld\n",
478 				PTR_ERR(dpaux->rst));
479 			return PTR_ERR(dpaux->rst);
480 		}
481 	}
482 
483 	dpaux->clk = devm_clk_get(&pdev->dev, NULL);
484 	if (IS_ERR(dpaux->clk)) {
485 		dev_err(&pdev->dev, "failed to get module clock: %ld\n",
486 			PTR_ERR(dpaux->clk));
487 		return PTR_ERR(dpaux->clk);
488 	}
489 
490 	dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");
491 	if (IS_ERR(dpaux->clk_parent)) {
492 		dev_err(&pdev->dev, "failed to get parent clock: %ld\n",
493 			PTR_ERR(dpaux->clk_parent));
494 		return PTR_ERR(dpaux->clk_parent);
495 	}
496 
497 	err = clk_set_rate(dpaux->clk_parent, 270000000);
498 	if (err < 0) {
499 		dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
500 			err);
501 		return err;
502 	}
503 
504 	dpaux->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
505 	if (IS_ERR(dpaux->vdd)) {
506 		if (PTR_ERR(dpaux->vdd) != -ENODEV) {
507 			if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)
508 				dev_err(&pdev->dev,
509 					"failed to get VDD supply: %ld\n",
510 					PTR_ERR(dpaux->vdd));
511 
512 			return PTR_ERR(dpaux->vdd);
513 		}
514 
515 		dpaux->vdd = NULL;
516 	}
517 
518 	platform_set_drvdata(pdev, dpaux);
519 	pm_runtime_enable(&pdev->dev);
520 	pm_runtime_get_sync(&pdev->dev);
521 
522 	err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
523 			       dev_name(dpaux->dev), dpaux);
524 	if (err < 0) {
525 		dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
526 			dpaux->irq, err);
527 		return err;
528 	}
529 
530 	disable_irq(dpaux->irq);
531 
532 	dpaux->aux.transfer = tegra_dpaux_transfer;
533 	dpaux->aux.dev = &pdev->dev;
534 
535 	drm_dp_aux_init(&dpaux->aux);
536 
537 	/*
538 	 * Assume that by default the DPAUX/I2C pads will be used for HDMI,
539 	 * so power them up and configure them in I2C mode.
540 	 *
541 	 * The DPAUX code paths reconfigure the pads in AUX mode, but there
542 	 * is no possibility to perform the I2C mode configuration in the
543 	 * HDMI path.
544 	 */
545 	err = tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_I2C);
546 	if (err < 0)
547 		return err;
548 
549 #ifdef CONFIG_GENERIC_PINCONF
550 	dpaux->desc.name = dev_name(&pdev->dev);
551 	dpaux->desc.pins = tegra_dpaux_pins;
552 	dpaux->desc.npins = ARRAY_SIZE(tegra_dpaux_pins);
553 	dpaux->desc.pctlops = &tegra_dpaux_pinctrl_ops;
554 	dpaux->desc.pmxops = &tegra_dpaux_pinmux_ops;
555 	dpaux->desc.owner = THIS_MODULE;
556 
557 	dpaux->pinctrl = devm_pinctrl_register(&pdev->dev, &dpaux->desc, dpaux);
558 	if (IS_ERR(dpaux->pinctrl)) {
559 		dev_err(&pdev->dev, "failed to register pincontrol\n");
560 		return PTR_ERR(dpaux->pinctrl);
561 	}
562 #endif
563 	/* enable and clear all interrupts */
564 	value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
565 		DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
566 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);
567 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
568 
569 	mutex_lock(&dpaux_lock);
570 	list_add_tail(&dpaux->list, &dpaux_list);
571 	mutex_unlock(&dpaux_lock);
572 
573 	return 0;
574 }
575 
576 static int tegra_dpaux_remove(struct platform_device *pdev)
577 {
578 	struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
579 
580 	cancel_work_sync(&dpaux->work);
581 
582 	/* make sure pads are powered down when not in use */
583 	tegra_dpaux_pad_power_down(dpaux);
584 
585 	pm_runtime_put_sync(&pdev->dev);
586 	pm_runtime_disable(&pdev->dev);
587 
588 	mutex_lock(&dpaux_lock);
589 	list_del(&dpaux->list);
590 	mutex_unlock(&dpaux_lock);
591 
592 	return 0;
593 }
594 
595 #ifdef CONFIG_PM
596 static int tegra_dpaux_suspend(struct device *dev)
597 {
598 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
599 	int err = 0;
600 
601 	if (dpaux->rst) {
602 		err = reset_control_assert(dpaux->rst);
603 		if (err < 0) {
604 			dev_err(dev, "failed to assert reset: %d\n", err);
605 			return err;
606 		}
607 	}
608 
609 	usleep_range(1000, 2000);
610 
611 	clk_disable_unprepare(dpaux->clk_parent);
612 	clk_disable_unprepare(dpaux->clk);
613 
614 	return err;
615 }
616 
617 static int tegra_dpaux_resume(struct device *dev)
618 {
619 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
620 	int err;
621 
622 	err = clk_prepare_enable(dpaux->clk);
623 	if (err < 0) {
624 		dev_err(dev, "failed to enable clock: %d\n", err);
625 		return err;
626 	}
627 
628 	err = clk_prepare_enable(dpaux->clk_parent);
629 	if (err < 0) {
630 		dev_err(dev, "failed to enable parent clock: %d\n", err);
631 		goto disable_clk;
632 	}
633 
634 	usleep_range(1000, 2000);
635 
636 	if (dpaux->rst) {
637 		err = reset_control_deassert(dpaux->rst);
638 		if (err < 0) {
639 			dev_err(dev, "failed to deassert reset: %d\n", err);
640 			goto disable_parent;
641 		}
642 
643 		usleep_range(1000, 2000);
644 	}
645 
646 	return 0;
647 
648 disable_parent:
649 	clk_disable_unprepare(dpaux->clk_parent);
650 disable_clk:
651 	clk_disable_unprepare(dpaux->clk);
652 	return err;
653 }
654 #endif
655 
656 static const struct dev_pm_ops tegra_dpaux_pm_ops = {
657 	SET_RUNTIME_PM_OPS(tegra_dpaux_suspend, tegra_dpaux_resume, NULL)
658 };
659 
660 static const struct tegra_dpaux_soc tegra124_dpaux_soc = {
661 	.cmh = 0x02,
662 	.drvz = 0x04,
663 	.drvi = 0x18,
664 };
665 
666 static const struct tegra_dpaux_soc tegra210_dpaux_soc = {
667 	.cmh = 0x02,
668 	.drvz = 0x04,
669 	.drvi = 0x30,
670 };
671 
672 static const struct tegra_dpaux_soc tegra194_dpaux_soc = {
673 	.cmh = 0x02,
674 	.drvz = 0x04,
675 	.drvi = 0x2c,
676 };
677 
678 static const struct of_device_id tegra_dpaux_of_match[] = {
679 	{ .compatible = "nvidia,tegra194-dpaux", .data = &tegra194_dpaux_soc },
680 	{ .compatible = "nvidia,tegra186-dpaux", .data = &tegra210_dpaux_soc },
681 	{ .compatible = "nvidia,tegra210-dpaux", .data = &tegra210_dpaux_soc },
682 	{ .compatible = "nvidia,tegra124-dpaux", .data = &tegra124_dpaux_soc },
683 	{ },
684 };
685 MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);
686 
687 struct platform_driver tegra_dpaux_driver = {
688 	.driver = {
689 		.name = "tegra-dpaux",
690 		.of_match_table = tegra_dpaux_of_match,
691 		.pm = &tegra_dpaux_pm_ops,
692 	},
693 	.probe = tegra_dpaux_probe,
694 	.remove = tegra_dpaux_remove,
695 };
696 
697 struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np)
698 {
699 	struct tegra_dpaux *dpaux;
700 
701 	mutex_lock(&dpaux_lock);
702 
703 	list_for_each_entry(dpaux, &dpaux_list, list)
704 		if (np == dpaux->dev->of_node) {
705 			mutex_unlock(&dpaux_lock);
706 			return &dpaux->aux;
707 		}
708 
709 	mutex_unlock(&dpaux_lock);
710 
711 	return NULL;
712 }
713 
714 int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)
715 {
716 	struct tegra_dpaux *dpaux = to_dpaux(aux);
717 	unsigned long timeout;
718 	int err;
719 
720 	aux->drm_dev = output->connector.dev;
721 	err = drm_dp_aux_register(aux);
722 	if (err < 0)
723 		return err;
724 
725 	output->connector.polled = DRM_CONNECTOR_POLL_HPD;
726 	dpaux->output = output;
727 
728 	if (output->panel) {
729 		enum drm_connector_status status;
730 
731 		if (dpaux->vdd) {
732 			err = regulator_enable(dpaux->vdd);
733 			if (err < 0)
734 				return err;
735 		}
736 
737 		timeout = jiffies + msecs_to_jiffies(250);
738 
739 		while (time_before(jiffies, timeout)) {
740 			status = drm_dp_aux_detect(aux);
741 
742 			if (status == connector_status_connected)
743 				break;
744 
745 			usleep_range(1000, 2000);
746 		}
747 
748 		if (status != connector_status_connected)
749 			return -ETIMEDOUT;
750 	}
751 
752 	enable_irq(dpaux->irq);
753 	return 0;
754 }
755 
756 int drm_dp_aux_detach(struct drm_dp_aux *aux)
757 {
758 	struct tegra_dpaux *dpaux = to_dpaux(aux);
759 	unsigned long timeout;
760 	int err;
761 
762 	drm_dp_aux_unregister(aux);
763 	disable_irq(dpaux->irq);
764 
765 	if (dpaux->output->panel) {
766 		enum drm_connector_status status;
767 
768 		if (dpaux->vdd) {
769 			err = regulator_disable(dpaux->vdd);
770 			if (err < 0)
771 				return err;
772 		}
773 
774 		timeout = jiffies + msecs_to_jiffies(250);
775 
776 		while (time_before(jiffies, timeout)) {
777 			status = drm_dp_aux_detect(aux);
778 
779 			if (status == connector_status_disconnected)
780 				break;
781 
782 			usleep_range(1000, 2000);
783 		}
784 
785 		if (status != connector_status_disconnected)
786 			return -ETIMEDOUT;
787 
788 		dpaux->output = NULL;
789 	}
790 
791 	return 0;
792 }
793 
794 enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)
795 {
796 	struct tegra_dpaux *dpaux = to_dpaux(aux);
797 	u32 value;
798 
799 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
800 
801 	if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)
802 		return connector_status_connected;
803 
804 	return connector_status_disconnected;
805 }
806 
807 int drm_dp_aux_enable(struct drm_dp_aux *aux)
808 {
809 	struct tegra_dpaux *dpaux = to_dpaux(aux);
810 
811 	return tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_AUX);
812 }
813 
814 int drm_dp_aux_disable(struct drm_dp_aux *aux)
815 {
816 	struct tegra_dpaux *dpaux = to_dpaux(aux);
817 
818 	tegra_dpaux_pad_power_down(dpaux);
819 
820 	return 0;
821 }
822