xref: /openbmc/linux/drivers/gpu/drm/tegra/dpaux.c (revision dc6a81c3)
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/gpio.h>
9 #include <linux/interrupt.h>
10 #include <linux/io.h>
11 #include <linux/module.h>
12 #include <linux/of_device.h>
13 #include <linux/of_gpio.h>
14 #include <linux/pinctrl/pinconf-generic.h>
15 #include <linux/pinctrl/pinctrl.h>
16 #include <linux/pinctrl/pinmux.h>
17 #include <linux/platform_device.h>
18 #include <linux/pm_runtime.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/reset.h>
21 #include <linux/workqueue.h>
22 
23 #include <drm/drm_dp_helper.h>
24 #include <drm/drm_panel.h>
25 
26 #include "dp.h"
27 #include "dpaux.h"
28 #include "drm.h"
29 #include "trace.h"
30 
31 static DEFINE_MUTEX(dpaux_lock);
32 static LIST_HEAD(dpaux_list);
33 
34 struct tegra_dpaux_soc {
35 	unsigned int cmh;
36 	unsigned int drvz;
37 	unsigned int drvi;
38 };
39 
40 struct tegra_dpaux {
41 	struct drm_dp_aux aux;
42 	struct device *dev;
43 
44 	const struct tegra_dpaux_soc *soc;
45 
46 	void __iomem *regs;
47 	int irq;
48 
49 	struct tegra_output *output;
50 
51 	struct reset_control *rst;
52 	struct clk *clk_parent;
53 	struct clk *clk;
54 
55 	struct regulator *vdd;
56 
57 	struct completion complete;
58 	struct work_struct work;
59 	struct list_head list;
60 
61 #ifdef CONFIG_GENERIC_PINCONF
62 	struct pinctrl_dev *pinctrl;
63 	struct pinctrl_desc desc;
64 #endif
65 };
66 
67 static inline struct tegra_dpaux *to_dpaux(struct drm_dp_aux *aux)
68 {
69 	return container_of(aux, struct tegra_dpaux, aux);
70 }
71 
72 static inline struct tegra_dpaux *work_to_dpaux(struct work_struct *work)
73 {
74 	return container_of(work, struct tegra_dpaux, work);
75 }
76 
77 static inline u32 tegra_dpaux_readl(struct tegra_dpaux *dpaux,
78 				    unsigned int offset)
79 {
80 	u32 value = readl(dpaux->regs + (offset << 2));
81 
82 	trace_dpaux_readl(dpaux->dev, offset, value);
83 
84 	return value;
85 }
86 
87 static inline void tegra_dpaux_writel(struct tegra_dpaux *dpaux,
88 				      u32 value, unsigned int offset)
89 {
90 	trace_dpaux_writel(dpaux->dev, offset, value);
91 	writel(value, dpaux->regs + (offset << 2));
92 }
93 
94 static void tegra_dpaux_write_fifo(struct tegra_dpaux *dpaux, const u8 *buffer,
95 				   size_t size)
96 {
97 	size_t i, j;
98 
99 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
100 		size_t num = min_t(size_t, size - i * 4, 4);
101 		u32 value = 0;
102 
103 		for (j = 0; j < num; j++)
104 			value |= buffer[i * 4 + j] << (j * 8);
105 
106 		tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXDATA_WRITE(i));
107 	}
108 }
109 
110 static void tegra_dpaux_read_fifo(struct tegra_dpaux *dpaux, u8 *buffer,
111 				  size_t size)
112 {
113 	size_t i, j;
114 
115 	for (i = 0; i < DIV_ROUND_UP(size, 4); i++) {
116 		size_t num = min_t(size_t, size - i * 4, 4);
117 		u32 value;
118 
119 		value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXDATA_READ(i));
120 
121 		for (j = 0; j < num; j++)
122 			buffer[i * 4 + j] = value >> (j * 8);
123 	}
124 }
125 
126 static ssize_t tegra_dpaux_transfer(struct drm_dp_aux *aux,
127 				    struct drm_dp_aux_msg *msg)
128 {
129 	unsigned long timeout = msecs_to_jiffies(250);
130 	struct tegra_dpaux *dpaux = to_dpaux(aux);
131 	unsigned long status;
132 	ssize_t ret = 0;
133 	u8 reply = 0;
134 	u32 value;
135 
136 	/* Tegra has 4x4 byte DP AUX transmit and receive FIFOs. */
137 	if (msg->size > 16)
138 		return -EINVAL;
139 
140 	/*
141 	 * Allow zero-sized messages only for I2C, in which case they specify
142 	 * address-only transactions.
143 	 */
144 	if (msg->size < 1) {
145 		switch (msg->request & ~DP_AUX_I2C_MOT) {
146 		case DP_AUX_I2C_WRITE_STATUS_UPDATE:
147 		case DP_AUX_I2C_WRITE:
148 		case DP_AUX_I2C_READ:
149 			value = DPAUX_DP_AUXCTL_CMD_ADDRESS_ONLY;
150 			break;
151 
152 		default:
153 			return -EINVAL;
154 		}
155 	} else {
156 		/* For non-zero-sized messages, set the CMDLEN field. */
157 		value = DPAUX_DP_AUXCTL_CMDLEN(msg->size - 1);
158 	}
159 
160 	switch (msg->request & ~DP_AUX_I2C_MOT) {
161 	case DP_AUX_I2C_WRITE:
162 		if (msg->request & DP_AUX_I2C_MOT)
163 			value |= DPAUX_DP_AUXCTL_CMD_MOT_WR;
164 		else
165 			value |= DPAUX_DP_AUXCTL_CMD_I2C_WR;
166 
167 		break;
168 
169 	case DP_AUX_I2C_READ:
170 		if (msg->request & DP_AUX_I2C_MOT)
171 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RD;
172 		else
173 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RD;
174 
175 		break;
176 
177 	case DP_AUX_I2C_WRITE_STATUS_UPDATE:
178 		if (msg->request & DP_AUX_I2C_MOT)
179 			value |= DPAUX_DP_AUXCTL_CMD_MOT_RQ;
180 		else
181 			value |= DPAUX_DP_AUXCTL_CMD_I2C_RQ;
182 
183 		break;
184 
185 	case DP_AUX_NATIVE_WRITE:
186 		value |= DPAUX_DP_AUXCTL_CMD_AUX_WR;
187 		break;
188 
189 	case DP_AUX_NATIVE_READ:
190 		value |= DPAUX_DP_AUXCTL_CMD_AUX_RD;
191 		break;
192 
193 	default:
194 		return -EINVAL;
195 	}
196 
197 	tegra_dpaux_writel(dpaux, msg->address, DPAUX_DP_AUXADDR);
198 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
199 
200 	if ((msg->request & DP_AUX_I2C_READ) == 0) {
201 		tegra_dpaux_write_fifo(dpaux, msg->buffer, msg->size);
202 		ret = msg->size;
203 	}
204 
205 	/* start transaction */
206 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXCTL);
207 	value |= DPAUX_DP_AUXCTL_TRANSACTREQ;
208 	tegra_dpaux_writel(dpaux, value, DPAUX_DP_AUXCTL);
209 
210 	status = wait_for_completion_timeout(&dpaux->complete, timeout);
211 	if (!status)
212 		return -ETIMEDOUT;
213 
214 	/* read status and clear errors */
215 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
216 	tegra_dpaux_writel(dpaux, 0xf00, DPAUX_DP_AUXSTAT);
217 
218 	if (value & DPAUX_DP_AUXSTAT_TIMEOUT_ERROR)
219 		return -ETIMEDOUT;
220 
221 	if ((value & DPAUX_DP_AUXSTAT_RX_ERROR) ||
222 	    (value & DPAUX_DP_AUXSTAT_SINKSTAT_ERROR) ||
223 	    (value & DPAUX_DP_AUXSTAT_NO_STOP_ERROR))
224 		return -EIO;
225 
226 	switch ((value & DPAUX_DP_AUXSTAT_REPLY_TYPE_MASK) >> 16) {
227 	case 0x00:
228 		reply = DP_AUX_NATIVE_REPLY_ACK;
229 		break;
230 
231 	case 0x01:
232 		reply = DP_AUX_NATIVE_REPLY_NACK;
233 		break;
234 
235 	case 0x02:
236 		reply = DP_AUX_NATIVE_REPLY_DEFER;
237 		break;
238 
239 	case 0x04:
240 		reply = DP_AUX_I2C_REPLY_NACK;
241 		break;
242 
243 	case 0x08:
244 		reply = DP_AUX_I2C_REPLY_DEFER;
245 		break;
246 	}
247 
248 	if ((msg->size > 0) && (msg->reply == DP_AUX_NATIVE_REPLY_ACK)) {
249 		if (msg->request & DP_AUX_I2C_READ) {
250 			size_t count = value & DPAUX_DP_AUXSTAT_REPLY_MASK;
251 
252 			/*
253 			 * There might be a smarter way to do this, but since
254 			 * the DP helpers will already retry transactions for
255 			 * an -EBUSY return value, simply reuse that instead.
256 			 */
257 			if (count != msg->size) {
258 				ret = -EBUSY;
259 				goto out;
260 			}
261 
262 			tegra_dpaux_read_fifo(dpaux, msg->buffer, count);
263 			ret = count;
264 		}
265 	}
266 
267 	msg->reply = reply;
268 
269 out:
270 	return ret;
271 }
272 
273 static void tegra_dpaux_hotplug(struct work_struct *work)
274 {
275 	struct tegra_dpaux *dpaux = work_to_dpaux(work);
276 
277 	if (dpaux->output)
278 		drm_helper_hpd_irq_event(dpaux->output->connector.dev);
279 }
280 
281 static irqreturn_t tegra_dpaux_irq(int irq, void *data)
282 {
283 	struct tegra_dpaux *dpaux = data;
284 	irqreturn_t ret = IRQ_HANDLED;
285 	u32 value;
286 
287 	/* clear interrupts */
288 	value = tegra_dpaux_readl(dpaux, DPAUX_INTR_AUX);
289 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
290 
291 	if (value & (DPAUX_INTR_PLUG_EVENT | DPAUX_INTR_UNPLUG_EVENT))
292 		schedule_work(&dpaux->work);
293 
294 	if (value & DPAUX_INTR_IRQ_EVENT) {
295 		/* TODO: handle this */
296 	}
297 
298 	if (value & DPAUX_INTR_AUX_DONE)
299 		complete(&dpaux->complete);
300 
301 	return ret;
302 }
303 
304 enum tegra_dpaux_functions {
305 	DPAUX_PADCTL_FUNC_AUX,
306 	DPAUX_PADCTL_FUNC_I2C,
307 	DPAUX_PADCTL_FUNC_OFF,
308 };
309 
310 static void tegra_dpaux_pad_power_down(struct tegra_dpaux *dpaux)
311 {
312 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
313 
314 	value |= DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
315 
316 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
317 }
318 
319 static void tegra_dpaux_pad_power_up(struct tegra_dpaux *dpaux)
320 {
321 	u32 value = tegra_dpaux_readl(dpaux, DPAUX_HYBRID_SPARE);
322 
323 	value &= ~DPAUX_HYBRID_SPARE_PAD_POWER_DOWN;
324 
325 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_SPARE);
326 }
327 
328 static int tegra_dpaux_pad_config(struct tegra_dpaux *dpaux, unsigned function)
329 {
330 	u32 value;
331 
332 	switch (function) {
333 	case DPAUX_PADCTL_FUNC_AUX:
334 		value = DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
335 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
336 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
337 			DPAUX_HYBRID_PADCTL_AUX_INPUT_RCV |
338 			DPAUX_HYBRID_PADCTL_MODE_AUX;
339 		break;
340 
341 	case DPAUX_PADCTL_FUNC_I2C:
342 		value = DPAUX_HYBRID_PADCTL_I2C_SDA_INPUT_RCV |
343 			DPAUX_HYBRID_PADCTL_I2C_SCL_INPUT_RCV |
344 			DPAUX_HYBRID_PADCTL_AUX_CMH(dpaux->soc->cmh) |
345 			DPAUX_HYBRID_PADCTL_AUX_DRVZ(dpaux->soc->drvz) |
346 			DPAUX_HYBRID_PADCTL_AUX_DRVI(dpaux->soc->drvi) |
347 			DPAUX_HYBRID_PADCTL_MODE_I2C;
348 		break;
349 
350 	case DPAUX_PADCTL_FUNC_OFF:
351 		tegra_dpaux_pad_power_down(dpaux);
352 		return 0;
353 
354 	default:
355 		return -ENOTSUPP;
356 	}
357 
358 	tegra_dpaux_writel(dpaux, value, DPAUX_HYBRID_PADCTL);
359 	tegra_dpaux_pad_power_up(dpaux);
360 
361 	return 0;
362 }
363 
364 #ifdef CONFIG_GENERIC_PINCONF
365 static const struct pinctrl_pin_desc tegra_dpaux_pins[] = {
366 	PINCTRL_PIN(0, "DP_AUX_CHx_P"),
367 	PINCTRL_PIN(1, "DP_AUX_CHx_N"),
368 };
369 
370 static const unsigned tegra_dpaux_pin_numbers[] = { 0, 1 };
371 
372 static const char * const tegra_dpaux_groups[] = {
373 	"dpaux-io",
374 };
375 
376 static const char * const tegra_dpaux_functions[] = {
377 	"aux",
378 	"i2c",
379 	"off",
380 };
381 
382 static int tegra_dpaux_get_groups_count(struct pinctrl_dev *pinctrl)
383 {
384 	return ARRAY_SIZE(tegra_dpaux_groups);
385 }
386 
387 static const char *tegra_dpaux_get_group_name(struct pinctrl_dev *pinctrl,
388 					      unsigned int group)
389 {
390 	return tegra_dpaux_groups[group];
391 }
392 
393 static int tegra_dpaux_get_group_pins(struct pinctrl_dev *pinctrl,
394 				      unsigned group, const unsigned **pins,
395 				      unsigned *num_pins)
396 {
397 	*pins = tegra_dpaux_pin_numbers;
398 	*num_pins = ARRAY_SIZE(tegra_dpaux_pin_numbers);
399 
400 	return 0;
401 }
402 
403 static const struct pinctrl_ops tegra_dpaux_pinctrl_ops = {
404 	.get_groups_count = tegra_dpaux_get_groups_count,
405 	.get_group_name = tegra_dpaux_get_group_name,
406 	.get_group_pins = tegra_dpaux_get_group_pins,
407 	.dt_node_to_map = pinconf_generic_dt_node_to_map_group,
408 	.dt_free_map = pinconf_generic_dt_free_map,
409 };
410 
411 static int tegra_dpaux_get_functions_count(struct pinctrl_dev *pinctrl)
412 {
413 	return ARRAY_SIZE(tegra_dpaux_functions);
414 }
415 
416 static const char *tegra_dpaux_get_function_name(struct pinctrl_dev *pinctrl,
417 						 unsigned int function)
418 {
419 	return tegra_dpaux_functions[function];
420 }
421 
422 static int tegra_dpaux_get_function_groups(struct pinctrl_dev *pinctrl,
423 					   unsigned int function,
424 					   const char * const **groups,
425 					   unsigned * const num_groups)
426 {
427 	*num_groups = ARRAY_SIZE(tegra_dpaux_groups);
428 	*groups = tegra_dpaux_groups;
429 
430 	return 0;
431 }
432 
433 static int tegra_dpaux_set_mux(struct pinctrl_dev *pinctrl,
434 			       unsigned int function, unsigned int group)
435 {
436 	struct tegra_dpaux *dpaux = pinctrl_dev_get_drvdata(pinctrl);
437 
438 	return tegra_dpaux_pad_config(dpaux, function);
439 }
440 
441 static const struct pinmux_ops tegra_dpaux_pinmux_ops = {
442 	.get_functions_count = tegra_dpaux_get_functions_count,
443 	.get_function_name = tegra_dpaux_get_function_name,
444 	.get_function_groups = tegra_dpaux_get_function_groups,
445 	.set_mux = tegra_dpaux_set_mux,
446 };
447 #endif
448 
449 static int tegra_dpaux_probe(struct platform_device *pdev)
450 {
451 	struct tegra_dpaux *dpaux;
452 	struct resource *regs;
453 	u32 value;
454 	int err;
455 
456 	dpaux = devm_kzalloc(&pdev->dev, sizeof(*dpaux), GFP_KERNEL);
457 	if (!dpaux)
458 		return -ENOMEM;
459 
460 	dpaux->soc = of_device_get_match_data(&pdev->dev);
461 	INIT_WORK(&dpaux->work, tegra_dpaux_hotplug);
462 	init_completion(&dpaux->complete);
463 	INIT_LIST_HEAD(&dpaux->list);
464 	dpaux->dev = &pdev->dev;
465 
466 	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
467 	dpaux->regs = devm_ioremap_resource(&pdev->dev, regs);
468 	if (IS_ERR(dpaux->regs))
469 		return PTR_ERR(dpaux->regs);
470 
471 	dpaux->irq = platform_get_irq(pdev, 0);
472 	if (dpaux->irq < 0) {
473 		dev_err(&pdev->dev, "failed to get IRQ\n");
474 		return -ENXIO;
475 	}
476 
477 	if (!pdev->dev.pm_domain) {
478 		dpaux->rst = devm_reset_control_get(&pdev->dev, "dpaux");
479 		if (IS_ERR(dpaux->rst)) {
480 			dev_err(&pdev->dev,
481 				"failed to get reset control: %ld\n",
482 				PTR_ERR(dpaux->rst));
483 			return PTR_ERR(dpaux->rst);
484 		}
485 	}
486 
487 	dpaux->clk = devm_clk_get(&pdev->dev, NULL);
488 	if (IS_ERR(dpaux->clk)) {
489 		dev_err(&pdev->dev, "failed to get module clock: %ld\n",
490 			PTR_ERR(dpaux->clk));
491 		return PTR_ERR(dpaux->clk);
492 	}
493 
494 	dpaux->clk_parent = devm_clk_get(&pdev->dev, "parent");
495 	if (IS_ERR(dpaux->clk_parent)) {
496 		dev_err(&pdev->dev, "failed to get parent clock: %ld\n",
497 			PTR_ERR(dpaux->clk_parent));
498 		return PTR_ERR(dpaux->clk_parent);
499 	}
500 
501 	err = clk_set_rate(dpaux->clk_parent, 270000000);
502 	if (err < 0) {
503 		dev_err(&pdev->dev, "failed to set clock to 270 MHz: %d\n",
504 			err);
505 		return err;
506 	}
507 
508 	dpaux->vdd = devm_regulator_get_optional(&pdev->dev, "vdd");
509 	if (IS_ERR(dpaux->vdd)) {
510 		if (PTR_ERR(dpaux->vdd) != -ENODEV) {
511 			if (PTR_ERR(dpaux->vdd) != -EPROBE_DEFER)
512 				dev_err(&pdev->dev,
513 					"failed to get VDD supply: %ld\n",
514 					PTR_ERR(dpaux->vdd));
515 
516 			return PTR_ERR(dpaux->vdd);
517 		}
518 
519 		dpaux->vdd = NULL;
520 	}
521 
522 	platform_set_drvdata(pdev, dpaux);
523 	pm_runtime_enable(&pdev->dev);
524 	pm_runtime_get_sync(&pdev->dev);
525 
526 	err = devm_request_irq(dpaux->dev, dpaux->irq, tegra_dpaux_irq, 0,
527 			       dev_name(dpaux->dev), dpaux);
528 	if (err < 0) {
529 		dev_err(dpaux->dev, "failed to request IRQ#%u: %d\n",
530 			dpaux->irq, err);
531 		return err;
532 	}
533 
534 	disable_irq(dpaux->irq);
535 
536 	dpaux->aux.transfer = tegra_dpaux_transfer;
537 	dpaux->aux.dev = &pdev->dev;
538 
539 	err = drm_dp_aux_register(&dpaux->aux);
540 	if (err < 0)
541 		return err;
542 
543 	/*
544 	 * Assume that by default the DPAUX/I2C pads will be used for HDMI,
545 	 * so power them up and configure them in I2C mode.
546 	 *
547 	 * The DPAUX code paths reconfigure the pads in AUX mode, but there
548 	 * is no possibility to perform the I2C mode configuration in the
549 	 * HDMI path.
550 	 */
551 	err = tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_I2C);
552 	if (err < 0)
553 		return err;
554 
555 #ifdef CONFIG_GENERIC_PINCONF
556 	dpaux->desc.name = dev_name(&pdev->dev);
557 	dpaux->desc.pins = tegra_dpaux_pins;
558 	dpaux->desc.npins = ARRAY_SIZE(tegra_dpaux_pins);
559 	dpaux->desc.pctlops = &tegra_dpaux_pinctrl_ops;
560 	dpaux->desc.pmxops = &tegra_dpaux_pinmux_ops;
561 	dpaux->desc.owner = THIS_MODULE;
562 
563 	dpaux->pinctrl = devm_pinctrl_register(&pdev->dev, &dpaux->desc, dpaux);
564 	if (IS_ERR(dpaux->pinctrl)) {
565 		dev_err(&pdev->dev, "failed to register pincontrol\n");
566 		return PTR_ERR(dpaux->pinctrl);
567 	}
568 #endif
569 	/* enable and clear all interrupts */
570 	value = DPAUX_INTR_AUX_DONE | DPAUX_INTR_IRQ_EVENT |
571 		DPAUX_INTR_UNPLUG_EVENT | DPAUX_INTR_PLUG_EVENT;
572 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_EN_AUX);
573 	tegra_dpaux_writel(dpaux, value, DPAUX_INTR_AUX);
574 
575 	mutex_lock(&dpaux_lock);
576 	list_add_tail(&dpaux->list, &dpaux_list);
577 	mutex_unlock(&dpaux_lock);
578 
579 	return 0;
580 }
581 
582 static int tegra_dpaux_remove(struct platform_device *pdev)
583 {
584 	struct tegra_dpaux *dpaux = platform_get_drvdata(pdev);
585 
586 	cancel_work_sync(&dpaux->work);
587 
588 	/* make sure pads are powered down when not in use */
589 	tegra_dpaux_pad_power_down(dpaux);
590 
591 	pm_runtime_put_sync(&pdev->dev);
592 	pm_runtime_disable(&pdev->dev);
593 
594 	drm_dp_aux_unregister(&dpaux->aux);
595 
596 	mutex_lock(&dpaux_lock);
597 	list_del(&dpaux->list);
598 	mutex_unlock(&dpaux_lock);
599 
600 	return 0;
601 }
602 
603 #ifdef CONFIG_PM
604 static int tegra_dpaux_suspend(struct device *dev)
605 {
606 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
607 	int err = 0;
608 
609 	if (dpaux->rst) {
610 		err = reset_control_assert(dpaux->rst);
611 		if (err < 0) {
612 			dev_err(dev, "failed to assert reset: %d\n", err);
613 			return err;
614 		}
615 	}
616 
617 	usleep_range(1000, 2000);
618 
619 	clk_disable_unprepare(dpaux->clk_parent);
620 	clk_disable_unprepare(dpaux->clk);
621 
622 	return err;
623 }
624 
625 static int tegra_dpaux_resume(struct device *dev)
626 {
627 	struct tegra_dpaux *dpaux = dev_get_drvdata(dev);
628 	int err;
629 
630 	err = clk_prepare_enable(dpaux->clk);
631 	if (err < 0) {
632 		dev_err(dev, "failed to enable clock: %d\n", err);
633 		return err;
634 	}
635 
636 	err = clk_prepare_enable(dpaux->clk_parent);
637 	if (err < 0) {
638 		dev_err(dev, "failed to enable parent clock: %d\n", err);
639 		goto disable_clk;
640 	}
641 
642 	usleep_range(1000, 2000);
643 
644 	if (dpaux->rst) {
645 		err = reset_control_deassert(dpaux->rst);
646 		if (err < 0) {
647 			dev_err(dev, "failed to deassert reset: %d\n", err);
648 			goto disable_parent;
649 		}
650 
651 		usleep_range(1000, 2000);
652 	}
653 
654 	return 0;
655 
656 disable_parent:
657 	clk_disable_unprepare(dpaux->clk_parent);
658 disable_clk:
659 	clk_disable_unprepare(dpaux->clk);
660 	return err;
661 }
662 #endif
663 
664 static const struct dev_pm_ops tegra_dpaux_pm_ops = {
665 	SET_RUNTIME_PM_OPS(tegra_dpaux_suspend, tegra_dpaux_resume, NULL)
666 };
667 
668 static const struct tegra_dpaux_soc tegra124_dpaux_soc = {
669 	.cmh = 0x02,
670 	.drvz = 0x04,
671 	.drvi = 0x18,
672 };
673 
674 static const struct tegra_dpaux_soc tegra210_dpaux_soc = {
675 	.cmh = 0x02,
676 	.drvz = 0x04,
677 	.drvi = 0x30,
678 };
679 
680 static const struct tegra_dpaux_soc tegra194_dpaux_soc = {
681 	.cmh = 0x02,
682 	.drvz = 0x04,
683 	.drvi = 0x2c,
684 };
685 
686 static const struct of_device_id tegra_dpaux_of_match[] = {
687 	{ .compatible = "nvidia,tegra194-dpaux", .data = &tegra194_dpaux_soc },
688 	{ .compatible = "nvidia,tegra186-dpaux", .data = &tegra210_dpaux_soc },
689 	{ .compatible = "nvidia,tegra210-dpaux", .data = &tegra210_dpaux_soc },
690 	{ .compatible = "nvidia,tegra124-dpaux", .data = &tegra124_dpaux_soc },
691 	{ },
692 };
693 MODULE_DEVICE_TABLE(of, tegra_dpaux_of_match);
694 
695 struct platform_driver tegra_dpaux_driver = {
696 	.driver = {
697 		.name = "tegra-dpaux",
698 		.of_match_table = tegra_dpaux_of_match,
699 		.pm = &tegra_dpaux_pm_ops,
700 	},
701 	.probe = tegra_dpaux_probe,
702 	.remove = tegra_dpaux_remove,
703 };
704 
705 struct drm_dp_aux *drm_dp_aux_find_by_of_node(struct device_node *np)
706 {
707 	struct tegra_dpaux *dpaux;
708 
709 	mutex_lock(&dpaux_lock);
710 
711 	list_for_each_entry(dpaux, &dpaux_list, list)
712 		if (np == dpaux->dev->of_node) {
713 			mutex_unlock(&dpaux_lock);
714 			return &dpaux->aux;
715 		}
716 
717 	mutex_unlock(&dpaux_lock);
718 
719 	return NULL;
720 }
721 
722 int drm_dp_aux_attach(struct drm_dp_aux *aux, struct tegra_output *output)
723 {
724 	struct tegra_dpaux *dpaux = to_dpaux(aux);
725 	unsigned long timeout;
726 	int err;
727 
728 	output->connector.polled = DRM_CONNECTOR_POLL_HPD;
729 	dpaux->output = output;
730 
731 	if (output->panel) {
732 		enum drm_connector_status status;
733 
734 		if (dpaux->vdd) {
735 			err = regulator_enable(dpaux->vdd);
736 			if (err < 0)
737 				return err;
738 		}
739 
740 		timeout = jiffies + msecs_to_jiffies(250);
741 
742 		while (time_before(jiffies, timeout)) {
743 			status = drm_dp_aux_detect(aux);
744 
745 			if (status == connector_status_connected)
746 				break;
747 
748 			usleep_range(1000, 2000);
749 		}
750 
751 		if (status != connector_status_connected)
752 			return -ETIMEDOUT;
753 	}
754 
755 	enable_irq(dpaux->irq);
756 	return 0;
757 }
758 
759 int drm_dp_aux_detach(struct drm_dp_aux *aux)
760 {
761 	struct tegra_dpaux *dpaux = to_dpaux(aux);
762 	unsigned long timeout;
763 	int err;
764 
765 	disable_irq(dpaux->irq);
766 
767 	if (dpaux->output->panel) {
768 		enum drm_connector_status status;
769 
770 		if (dpaux->vdd) {
771 			err = regulator_disable(dpaux->vdd);
772 			if (err < 0)
773 				return err;
774 		}
775 
776 		timeout = jiffies + msecs_to_jiffies(250);
777 
778 		while (time_before(jiffies, timeout)) {
779 			status = drm_dp_aux_detect(aux);
780 
781 			if (status == connector_status_disconnected)
782 				break;
783 
784 			usleep_range(1000, 2000);
785 		}
786 
787 		if (status != connector_status_disconnected)
788 			return -ETIMEDOUT;
789 
790 		dpaux->output = NULL;
791 	}
792 
793 	return 0;
794 }
795 
796 enum drm_connector_status drm_dp_aux_detect(struct drm_dp_aux *aux)
797 {
798 	struct tegra_dpaux *dpaux = to_dpaux(aux);
799 	u32 value;
800 
801 	value = tegra_dpaux_readl(dpaux, DPAUX_DP_AUXSTAT);
802 
803 	if (value & DPAUX_DP_AUXSTAT_HPD_STATUS)
804 		return connector_status_connected;
805 
806 	return connector_status_disconnected;
807 }
808 
809 int drm_dp_aux_enable(struct drm_dp_aux *aux)
810 {
811 	struct tegra_dpaux *dpaux = to_dpaux(aux);
812 
813 	return tegra_dpaux_pad_config(dpaux, DPAUX_PADCTL_FUNC_AUX);
814 }
815 
816 int drm_dp_aux_disable(struct drm_dp_aux *aux)
817 {
818 	struct tegra_dpaux *dpaux = to_dpaux(aux);
819 
820 	tegra_dpaux_pad_power_down(dpaux);
821 
822 	return 0;
823 }
824