xref: /linux/drivers/gpu/drm/tegra/dpaux.c (revision a4eb44a6435d6d8f9e642407a4a06f65eb90ca04) 
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_dp_aux_bus.h>
23 #include <drm/drm_panel.h>
24 
25 #include "dp.h"
26 #include "dpaux.h"
27 #include "drm.h"
28 #include "trace.h"
29 
30 static DEFINE_MUTEX(dpaux_lock);
31 static LIST_HEAD(dpaux_list);
32 
33 struct tegra_dpaux_soc {
34 	unsigned int cmh;
35 	unsigned int drvz;
36 	unsigned int drvi;
37 };
38 
39 struct tegra_dpaux {
40 	struct drm_dp_aux aux;
41 	struct device *dev;
42 
43 	const struct tegra_dpaux_soc *soc;
44 
45 	void __iomem *regs;
46 	int irq;
47 
48 	struct tegra_output *output;
49 
50 	struct reset_control *rst;
51 	struct clk *clk_parent;
52 	struct clk *clk;
53 
54 	struct regulator *vdd;
55 
56 	struct completion complete;
57 	struct work_struct work;
58 	struct list_head list;
59 
60 #ifdef CONFIG_GENERIC_PINCONF
61 	struct pinctrl_dev *pinctrl;
62 	struct pinctrl_desc desc;
63 #endif
64 };
65 
66 static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)
67 {
68 	return container_of(aux, struct tegra_dpaux, aux);
69 }
70 
71 static inline struct tegra_dpaux *work_to_dpaux(struct work_struct *work)
72 {
73 	return container_of(work, struct tegra_dpaux, work);
74 }
75 
76 static inline u32 tegra_dpaux_readl(struct tegra_dpaux *dpaux,
77 				    unsigned int offset)
78 {
79 	u32 value = readl(dpaux->regs + (offset << 2));
80 
81 	trace_dpaux_readl(dpaux->dev, offset, value);
82 
83 	return value;
84 }
85 
86 static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,
87 				      u32 value, unsigned int offset)
88 {
89 	trace_dpaux_writel(dpaux->dev, offset, value);
90 	writel(value, dpaux->regs + (offset << 2));
91 }
92 
93 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
94 				   size_t size)
95 {
96 	size_t i, j;
97 
98 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
99 		size_t num = min_t(size_t, size - i * 4, 4);
100 		u32 value = 0;
101 
102 		for (j = 0; j < num; j++)
103 			value |= buffer[i * 4 + j] << (j * 8);
104 
105 		tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
106 	}
107 }
108 
109 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
110 				  size_t size)
111 {
112 	size_t i, j;
113 
114 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
115 		size_t num = min_t(size_t, size - i * 4, 4);
116 		u32 value;
117 
118 		value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
119 
120 		for (j = 0; j < num; j++)
121 			buffer[i * 4 + j] = value >> (j * 8);
122 	}
123 }
124 
125 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
126 				    struct drm_dp_aux_msg *msg)
127 {
128 	unsigned long timeout = msecs_to_jiffies(250);
129 	struct tegra_dpaux *dpaux = to_dpaux(aux);
130 	unsigned long status;
131 	ssize_t ret = 0;
132 	u8 reply = 0;
133 	u32 value;
134 
135 	/* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
136 	if (msg->size > 16)
137 		return -EINVAL;
138 
139 	/*
140 	 * Allow zero-sized messages only for I2C, in which case they specify
141 	 * address-only transactions.
142 	 */
143 	if (msg->size < 1) {
144 		switch (msg->request & ~DP_AUX_I2C_MOT) {
145 		case DP_AUX_I2C_WRITE_STATUS_UPDATE:
146 		case DP_AUX_I2C_WRITE:
147 		case DP_AUX_I2C_READ:
148 			value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;
149 			break;
150 
151 		default:
152 			return -EINVAL;
153 		}
154 	} else {
155 		/* For non-zero-sized messages, set the CMDLEN field. */
156 		value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
157 	}
158 
159 	switch (msg->request & ~DP_AUX_I2C_MOT) {
160 	case DP_AUX_I2C_WRITE:
161 		if (msg->request & DP_AUX_I2C_MOT)
162 			value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;
163 		else
164 			value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;
165 
166 		break;
167 
168 	case DP_AUX_I2C_READ:
169 		if (msg->request & DP_AUX_I2C_MOT)
170 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;
171 		else
172 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;
173 
174 		break;
175 
176 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
177 		if (msg->request & DP_AUX_I2C_MOT)
178 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;
179 		else
180 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;
181 
182 		break;
183 
184 	case DP_AUX_NATIVE_WRITE:
185 		value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;
186 		break;
187 
188 	case DP_AUX_NATIVE_READ:
189 		value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;
190 		break;
191 
192 	default:
193 		return -EINVAL;
194 	}
195 
196 	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
197 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
198 
199 	if ((msg->request & DP_AUX_I2C_READ) == 0) {
200 		tegra_dpaux_write_fifo(dpaux, msg->buffer, msg->size);
201 		ret = msg->size;
202 	}
203 
204 	/* start transaction */
205 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXCTL);
206 	value |= DPAUX_DP_AUXCTL_TRANSACTREQ;
207 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
208 
209 	status = wait_for_completion_timeout(&dpaux->complete, timeout);
210 	if (!status)
211 		return -ETIMEDOUT;
212 
213 	/* read status and clear errors */
214 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
215 	tegra_dpaux_writel(dpaux, 0xf00, DPAUX_DP_AUXSTAT);
216 
217 	if (value & DPAUX_DP_AUXSTAT_TIMEOUT_ERROR)
218 		return -ETIMEDOUT;
219 
220 	if ((value & DPAUX_DP_AUXSTAT_RX_ERROR) ||
221 	    (value & DPAUX_DP_AUXSTAT_SINKSTAT_ERROR) ||
222 	    (value & DPAUX_DP_AUXSTAT_NO_STOP_ERROR))
223 		return -EIO;
224 
225 	switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) {
226 	case 0x00:
227 		reply = DP_AUX_NATIVE_REPLY_ACK;
228 		break;
229 
230 	case 0x01:
231 		reply = DP_AUX_NATIVE_REPLY_NACK;
232 		break;
233 
234 	case 0x02:
235 		reply = DP_AUX_NATIVE_REPLY_DEFER;
236 		break;
237 
238 	case 0x04:
239 		reply = DP_AUX_I2C_REPLY_NACK;
240 		break;
241 
242 	case 0x08:
243 		reply = DP_AUX_I2C_REPLY_DEFER;
244 		break;
245 	}
246 
247 	if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {
248 		if (msg->request & DP_AUX_I2C_READ) {
249 			size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;
250 
251 			/*
252 			 * There might be a smarter way to do this, but since
253 			 * the DP helpers will already retry transactions for
254 			 * an -EBUSY return value, simply reuse that instead.
255 			 */
256 			if (count != msg->size) {
257 				ret = -EBUSY;
258 				goto out;
259 			}
260 
261 			tegra_dpaux_read_fifo(dpaux, msg->buffer, count);
262 			ret = count;
263 		}
264 	}
265 
266 	msg->reply = reply;
267 
268 out:
269 	return ret;
270 }
271 
272 static void tegra_dpaux_hotplug(struct work_struct *work)
273 {
274 	struct tegra_dpaux *dpaux = work_to_dpaux(work);
275 
276 	if (dpaux->output)
277 		drm_helper_hpd_irq_event(dpaux->output->connector.dev);
278 }
279 
280 static irqreturn_t tegra_dpaux_irq(int irq, void *data)
281 {
282 	struct tegra_dpaux *dpaux = data;
283 	irqreturn_t ret = IRQ_HANDLED;
284 	u32 value;
285 
286 	/* clear interrupts */
287 	value = tegra_dpaux_readl(dpaux, DPAUX_INTR_AUX);
288 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
289 
290 	if (value & (DPAUX_INTR_PLUG_EVENT | DPAUX_INTR_UNPLUG_EVENT))
291 		schedule_work(&dpaux->work);
292 
293 	if (value & DPAUX_INTR_IRQ_EVENT) {
294 		/* TODO: handle this */
295 	}
296 
297 	if (value & DPAUX_INTR_AUX_DONE)
298 		complete(&dpaux->complete);
299 
300 	return ret;
301 }
302 
303 enum tegra_dpaux_functions {
304 	DPAUX_PADCTL_FUNC_AUX,
305 	DPAUX_PADCTL_FUNC_I2C,
306 	DPAUX_PADCTL_FUNC_OFF,
307 };
308 
309 static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
310 {
311 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
312 
313 	value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
314 
315 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
316 }
317 
318 static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)
319 {
320 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
321 
322 	value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
323 
324 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
325 }
326 
327 static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
328 {
329 	u32 value;
330 
331 	switch (function) {
332 	case DPAUX_PADCTL_FUNC_AUX:
333 		value = DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
334 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
335 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
336 			DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
337 			DPAUX_HYBRID_PADCTL_MODE_AUX;
338 		break;
339 
340 	case DPAUX_PADCTL_FUNC_I2C:
341 		value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
342 			DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
343 			DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
344 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
345 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
346 			DPAUX_HYBRID_PADCTL_MODE_I2C;
347 		break;
348 
349 	case DPAUX_PADCTL_FUNC_OFF:
350 		tegra_dpaux_pad_power_down(dpaux);
351 		return 0;
352 
353 	default:
354 		return -ENOTSUPP;
355 	}
356 
357 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
358 	tegra_dpaux_pad_power_up(dpaux);
359 
360 	return 0;
361 }
362 
363 #ifdef CONFIG_GENERIC_PINCONF
364 static const struct pinctrl_pin_desc tegra_dpaux_pins[] = {
365 	PINCTRL_PIN(0, "DP_AUX_CHx_P"),
366 	PINCTRL_PIN(1, "DP_AUX_CHx_N"),
367 };
368 
369 static const unsigned tegra_dpaux_pin_numbers[] = { 0, 1 };
370 
371 static const char * const tegra_dpaux_groups[] = {
372 	"dpaux-io",
373 };
374 
375 static const char * const tegra_dpaux_functions[] = {
376 	"aux",
377 	"i2c",
378 	"off",
379 };
380 
381 static int tegra_dpaux_get_groups_count(struct pinctrl_dev *pinctrl)
382 {
383 	return ARRAY_SIZE(tegra_dpaux_groups);
384 }
385 
386 static const char *tegra_dpaux_get_group_name(struct pinctrl_dev *pinctrl,
387 					      unsigned int group)
388 {
389 	return tegra_dpaux_groups[group];
390 }
391 
392 static int tegra_dpaux_get_group_pins(struct pinctrl_dev *pinctrl,
393 				      unsigned group, const unsigned **pins,
394 				      unsigned *num_pins)
395 {
396 	*pins = tegra_dpaux_pin_numbers;
397 	*num_pins = ARRAY_SIZE(tegra_dpaux_pin_numbers);
398 
399 	return 0;
400 }
401 
402 static const struct pinctrl_ops tegra_dpaux_pinctrl_ops = {
403 	.get_groups_count = tegra_dpaux_get_groups_count,
404 	.get_group_name = tegra_dpaux_get_group_name,
405 	.get_group_pins = tegra_dpaux_get_group_pins,
406 	.dt_node_to_map = pinconf_generic_dt_node_to_map_group,
407 	.dt_free_map = pinconf_generic_dt_free_map,
408 };
409 
410 static int tegra_dpaux_get_functions_count(struct pinctrl_dev *pinctrl)
411 {
412 	return ARRAY_SIZE(tegra_dpaux_functions);
413 }
414 
415 static const char *tegra_dpaux_get_function_name(struct pinctrl_dev *pinctrl,
416 						 unsigned int function)
417 {
418 	return tegra_dpaux_functions[function];
419 }
420 
421 static int tegra_dpaux_get_function_groups(struct pinctrl_dev *pinctrl,
422 					   unsigned int function,
423 					   const char * const **groups,
424 					   unsigned * const num_groups)
425 {
426 	*num_groups = ARRAY_SIZE(tegra_dpaux_groups);
427 	*groups = tegra_dpaux_groups;
428 
429 	return 0;
430 }
431 
432 static int tegra_dpaux_set_mux(struct pinctrl_dev *pinctrl,
433 			       unsigned int function, unsigned int group)
434 {
435 	struct tegra_dpaux *dpaux = pinctrl_dev_get_drvdata(pinctrl);
436 
437 	return tegra_dpaux_pad_config(dpaux, function);
438 }
439 
440 static const struct pinmux_ops tegra_dpaux_pinmux_ops = {
441 	.get_functions_count = tegra_dpaux_get_functions_count,
442 	.get_function_name = tegra_dpaux_get_function_name,
443 	.get_function_groups = tegra_dpaux_get_function_groups,
444 	.set_mux = tegra_dpaux_set_mux,
445 };
446 #endif
447 
448 static int tegra_dpaux_probe(struct platform_device *pdev)
449 {
450 	struct tegra_dpaux *dpaux;
451 	struct resource *regs;
452 	u32 value;
453 	int err;
454 
455 	dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);
456 	if (!dpaux)
457 		return -ENOMEM;
458 
459 	dpaux->soc = of_device_get_match_data(&pdev->dev);
460 	INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);
461 	init_completion(&dpaux->complete);
462 	INIT_LIST_HEAD(&dpaux->list);
463 	dpaux->dev = &pdev->dev;
464 
465 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
466 	dpaux->regs = devm_ioremap_resource(&pdev->dev, regs);
467 	if (IS_ERR(dpaux->regs))
468 		return PTR_ERR(dpaux->regs);
469 
470 	dpaux->irq = platform_get_irq(pdev, 0);
471 	if (dpaux->irq < 0)
472 		return -ENXIO;
473 
474 	if (!pdev->dev.pm_domain) {
475 		dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");
476 		if (IS_ERR(dpaux->rst)) {
477 			dev_err(&pdev->dev,
478 				"failed to get reset control: %ld\n",
479 				PTR_ERR(dpaux->rst));
480 			return PTR_ERR(dpaux->rst);
481 		}
482 	}
483 
484 	dpaux->clk = devm_clk_get(&pdev->dev, NULL);
485 	if (IS_ERR(dpaux->clk)) {
486 		dev_err(&pdev->dev, "failed to get module clock: %ld\n",
487 			PTR_ERR(dpaux->clk));
488 		return PTR_ERR(dpaux->clk);
489 	}
490 
491 	dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");
492 	if (IS_ERR(dpaux->clk_parent)) {
493 		dev_err(&pdev->dev, "failed to get parent clock: %ld\n",
494 			PTR_ERR(dpaux->clk_parent));
495 		return PTR_ERR(dpaux->clk_parent);
496 	}
497 
498 	err = clk_set_rate(dpaux->clk_parent, 270000000);
499 	if (err < 0) {
500 		dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
501 			err);
502 		return err;
503 	}
504 
505 	dpaux->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
506 	if (IS_ERR(dpaux->vdd)) {
507 		if (PTR_ERR(dpaux->vdd) != -ENODEV) {
508 			if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)
509 				dev_err(&pdev->dev,
510 					"failed to get VDD supply: %ld\n",
511 					PTR_ERR(dpaux->vdd));
512 
513 			return PTR_ERR(dpaux->vdd);
514 		}
515 
516 		dpaux->vdd = NULL;
517 	}
518 
519 	platform_set_drvdata(pdev, dpaux);
520 	pm_runtime_enable(&pdev->dev);
521 	pm_runtime_get_sync(&pdev->dev);
522 
523 	err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
524 			       dev_name(dpaux->dev), dpaux);
525 	if (err < 0) {
526 		dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
527 			dpaux->irq, err);
528 		return err;
529 	}
530 
531 	disable_irq(dpaux->irq);
532 
533 	dpaux->aux.transfer = tegra_dpaux_transfer;
534 	dpaux->aux.dev = &pdev->dev;
535 
536 	drm_dp_aux_init(&dpaux->aux);
537 
538 	/*
539 	 * Assume that by default the DPAUX/I2C pads will be used for HDMI,
540 	 * so power them up and configure them in I2C mode.
541 	 *
542 	 * The DPAUX code paths reconfigure the pads in AUX mode, but there
543 	 * is no possibility to perform the I2C mode configuration in the
544 	 * HDMI path.
545 	 */
546 	err = tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_I2C);
547 	if (err < 0)
548 		return err;
549 
550 #ifdef CONFIG_GENERIC_PINCONF
551 	dpaux->desc.name = dev_name(&pdev->dev);
552 	dpaux->desc.pins = tegra_dpaux_pins;
553 	dpaux->desc.npins = ARRAY_SIZE(tegra_dpaux_pins);
554 	dpaux->desc.pctlops = &tegra_dpaux_pinctrl_ops;
555 	dpaux->desc.pmxops = &tegra_dpaux_pinmux_ops;
556 	dpaux->desc.owner = THIS_MODULE;
557 
558 	dpaux->pinctrl = devm_pinctrl_register(&pdev->dev, &dpaux->desc, dpaux);
559 	if (IS_ERR(dpaux->pinctrl)) {
560 		dev_err(&pdev->dev, "failed to register pincontrol\n");
561 		return PTR_ERR(dpaux->pinctrl);
562 	}
563 #endif
564 	/* enable and clear all interrupts */
565 	value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
566 		DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
567 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);
568 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
569 
570 	mutex_lock(&dpaux_lock);
571 	list_add_tail(&dpaux->list, &dpaux_list);
572 	mutex_unlock(&dpaux_lock);
573 
574 	err = devm_of_dp_aux_populate_ep_devices(&dpaux->aux);
575 	if (err < 0) {
576 		dev_err(dpaux->dev, "failed to populate AUX bus: %d\n", err);
577 		return err;
578 	}
579 
580 	return 0;
581 }
582 
583 static int tegra_dpaux_remove(struct platform_device *pdev)
584 {
585 	struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
586 
587 	cancel_work_sync(&dpaux->work);
588 
589 	/* make sure pads are powered down when not in use */
590 	tegra_dpaux_pad_power_down(dpaux);
591 
592 	pm_runtime_put_sync(&pdev->dev);
593 	pm_runtime_disable(&pdev->dev);
594 
595 	mutex_lock(&dpaux_lock);
596 	list_del(&dpaux->list);
597 	mutex_unlock(&dpaux_lock);
598 
599 	return 0;
600 }
601 
602 #ifdef CONFIG_PM
603 static int tegra_dpaux_suspend(struct device *dev)
604 {
605 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
606 	int err = 0;
607 
608 	if (dpaux->rst) {
609 		err = reset_control_assert(dpaux->rst);
610 		if (err < 0) {
611 			dev_err(dev, "failed to assert reset: %d\n", err);
612 			return err;
613 		}
614 	}
615 
616 	usleep_range(1000, 2000);
617 
618 	clk_disable_unprepare(dpaux->clk_parent);
619 	clk_disable_unprepare(dpaux->clk);
620 
621 	return err;
622 }
623 
624 static int tegra_dpaux_resume(struct device *dev)
625 {
626 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
627 	int err;
628 
629 	err = clk_prepare_enable(dpaux->clk);
630 	if (err < 0) {
631 		dev_err(dev, "failed to enable clock: %d\n", err);
632 		return err;
633 	}
634 
635 	err = clk_prepare_enable(dpaux->clk_parent);
636 	if (err < 0) {
637 		dev_err(dev, "failed to enable parent clock: %d\n", err);
638 		goto disable_clk;
639 	}
640 
641 	usleep_range(1000, 2000);
642 
643 	if (dpaux->rst) {
644 		err = reset_control_deassert(dpaux->rst);
645 		if (err < 0) {
646 			dev_err(dev, "failed to deassert reset: %d\n", err);
647 			goto disable_parent;
648 		}
649 
650 		usleep_range(1000, 2000);
651 	}
652 
653 	return 0;
654 
655 disable_parent:
656 	clk_disable_unprepare(dpaux->clk_parent);
657 disable_clk:
658 	clk_disable_unprepare(dpaux->clk);
659 	return err;
660 }
661 #endif
662 
663 static const struct dev_pm_ops tegra_dpaux_pm_ops = {
664 	SET_RUNTIME_PM_OPS(tegra_dpaux_suspend, tegra_dpaux_resume, NULL)
665 };
666 
667 static const struct tegra_dpaux_soc tegra124_dpaux_soc = {
668 	.cmh = 0x02,
669 	.drvz = 0x04,
670 	.drvi = 0x18,
671 };
672 
673 static const struct tegra_dpaux_soc tegra210_dpaux_soc = {
674 	.cmh = 0x02,
675 	.drvz = 0x04,
676 	.drvi = 0x30,
677 };
678 
679 static const struct tegra_dpaux_soc tegra194_dpaux_soc = {
680 	.cmh = 0x02,
681 	.drvz = 0x04,
682 	.drvi = 0x2c,
683 };
684 
685 static const struct of_device_id tegra_dpaux_of_match[] = {
686 	{ .compatible = "nvidia,tegra194-dpaux", .data = &tegra194_dpaux_soc },
687 	{ .compatible = "nvidia,tegra186-dpaux", .data = &tegra210_dpaux_soc },
688 	{ .compatible = "nvidia,tegra210-dpaux", .data = &tegra210_dpaux_soc },
689 	{ .compatible = "nvidia,tegra124-dpaux", .data = &tegra124_dpaux_soc },
690 	{ },
691 };
692 MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);
693 
694 struct platform_driver tegra_dpaux_driver = {
695 	.driver = {
696 		.name = "tegra-dpaux",
697 		.of_match_table = tegra_dpaux_of_match,
698 		.pm = &tegra_dpaux_pm_ops,
699 	},
700 	.probe = tegra_dpaux_probe,
701 	.remove = tegra_dpaux_remove,
702 };
703 
704 struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np)
705 {
706 	struct tegra_dpaux *dpaux;
707 
708 	mutex_lock(&dpaux_lock);
709 
710 	list_for_each_entry(dpaux, &dpaux_list, list)
711 		if (np == dpaux->dev->of_node) {
712 			mutex_unlock(&dpaux_lock);
713 			return &dpaux->aux;
714 		}
715 
716 	mutex_unlock(&dpaux_lock);
717 
718 	return NULL;
719 }
720 
721 int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)
722 {
723 	struct tegra_dpaux *dpaux = to_dpaux(aux);
724 	unsigned long timeout;
725 	int err;
726 
727 	aux->drm_dev = output->connector.dev;
728 	err = drm_dp_aux_register(aux);
729 	if (err < 0)
730 		return err;
731 
732 	output->connector.polled = DRM_CONNECTOR_POLL_HPD;
733 	dpaux->output = output;
734 
735 	if (output->panel) {
736 		enum drm_connector_status status;
737 
738 		if (dpaux->vdd) {
739 			err = regulator_enable(dpaux->vdd);
740 			if (err < 0)
741 				return err;
742 		}
743 
744 		timeout = jiffies + msecs_to_jiffies(250);
745 
746 		while (time_before(jiffies, timeout)) {
747 			status = drm_dp_aux_detect(aux);
748 
749 			if (status == connector_status_connected)
750 				break;
751 
752 			usleep_range(1000, 2000);
753 		}
754 
755 		if (status != connector_status_connected)
756 			return -ETIMEDOUT;
757 	}
758 
759 	enable_irq(dpaux->irq);
760 	return 0;
761 }
762 
763 int drm_dp_aux_detach(struct drm_dp_aux *aux)
764 {
765 	struct tegra_dpaux *dpaux = to_dpaux(aux);
766 	unsigned long timeout;
767 	int err;
768 
769 	drm_dp_aux_unregister(aux);
770 	disable_irq(dpaux->irq);
771 
772 	if (dpaux->output->panel) {
773 		enum drm_connector_status status;
774 
775 		if (dpaux->vdd) {
776 			err = regulator_disable(dpaux->vdd);
777 			if (err < 0)
778 				return err;
779 		}
780 
781 		timeout = jiffies + msecs_to_jiffies(250);
782 
783 		while (time_before(jiffies, timeout)) {
784 			status = drm_dp_aux_detect(aux);
785 
786 			if (status == connector_status_disconnected)
787 				break;
788 
789 			usleep_range(1000, 2000);
790 		}
791 
792 		if (status != connector_status_disconnected)
793 			return -ETIMEDOUT;
794 
795 		dpaux->output = NULL;
796 	}
797 
798 	return 0;
799 }
800 
801 enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)
802 {
803 	struct tegra_dpaux *dpaux = to_dpaux(aux);
804 	u32 value;
805 
806 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
807 
808 	if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)
809 		return connector_status_connected;
810 
811 	return connector_status_disconnected;
812 }
813 
814 int drm_dp_aux_enable(struct drm_dp_aux *aux)
815 {
816 	struct tegra_dpaux *dpaux = to_dpaux(aux);
817 
818 	return tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_AUX);
819 }
820 
821 int drm_dp_aux_disable(struct drm_dp_aux *aux)
822 {
823 	struct tegra_dpaux *dpaux = to_dpaux(aux);
824 
825 	tegra_dpaux_pad_power_down(dpaux);
826 
827 	return 0;
828 }
829