1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2016 MediaTek Inc.
4  */
5 
6 #include <linux/delay.h>
7 #include <linux/err.h>
8 #include <linux/gpio/consumer.h>
9 #include <linux/i2c.h>
10 #include <linux/module.h>
11 #include <linux/of_graph.h>
12 #include <linux/pm_runtime.h>
13 #include <linux/regmap.h>
14 #include <linux/regulator/consumer.h>
15 
16 #include <drm/display/drm_dp_aux_bus.h>
17 #include <drm/display/drm_dp_helper.h>
18 #include <drm/drm_atomic_state_helper.h>
19 #include <drm/drm_bridge.h>
20 #include <drm/drm_edid.h>
21 #include <drm/drm_mipi_dsi.h>
22 #include <drm/drm_of.h>
23 #include <drm/drm_panel.h>
24 #include <drm/drm_print.h>
25 
26 #define PAGE0_AUXCH_CFG3	0x76
27 #define  AUXCH_CFG3_RESET	0xff
28 #define PAGE0_SWAUX_ADDR_7_0	0x7d
29 #define PAGE0_SWAUX_ADDR_15_8	0x7e
30 #define PAGE0_SWAUX_ADDR_23_16	0x7f
31 #define  SWAUX_ADDR_MASK	GENMASK(19, 0)
32 #define PAGE0_SWAUX_LENGTH	0x80
33 #define  SWAUX_LENGTH_MASK	GENMASK(3, 0)
34 #define  SWAUX_NO_PAYLOAD	BIT(7)
35 #define PAGE0_SWAUX_WDATA	0x81
36 #define PAGE0_SWAUX_RDATA	0x82
37 #define PAGE0_SWAUX_CTRL	0x83
38 #define  SWAUX_SEND		BIT(0)
39 #define PAGE0_SWAUX_STATUS	0x84
40 #define  SWAUX_M_MASK		GENMASK(4, 0)
41 #define  SWAUX_STATUS_MASK	GENMASK(7, 5)
42 #define  SWAUX_STATUS_NACK	(0x1 << 5)
43 #define  SWAUX_STATUS_DEFER	(0x2 << 5)
44 #define  SWAUX_STATUS_ACKM	(0x3 << 5)
45 #define  SWAUX_STATUS_INVALID	(0x4 << 5)
46 #define  SWAUX_STATUS_I2C_NACK	(0x5 << 5)
47 #define  SWAUX_STATUS_I2C_DEFER	(0x6 << 5)
48 #define  SWAUX_STATUS_TIMEOUT	(0x7 << 5)
49 
50 #define PAGE2_GPIO_H		0xa7
51 #define  PS_GPIO9		BIT(1)
52 #define PAGE2_I2C_BYPASS	0xea
53 #define  I2C_BYPASS_EN		0xd0
54 #define PAGE2_MCS_EN		0xf3
55 #define  MCS_EN			BIT(0)
56 
57 #define PAGE3_SET_ADD		0xfe
58 #define  VDO_CTL_ADD		0x13
59 #define  VDO_DIS		0x18
60 #define  VDO_EN			0x1c
61 
62 #define NUM_MIPI_LANES		4
63 
64 #define COMMON_PS8640_REGMAP_CONFIG \
65 	.reg_bits = 8, \
66 	.val_bits = 8, \
67 	.cache_type = REGCACHE_NONE
68 
69 /*
70  * PS8640 uses multiple addresses:
71  * page[0]: for DP control
72  * page[1]: for VIDEO Bridge
73  * page[2]: for control top
74  * page[3]: for DSI Link Control1
75  * page[4]: for MIPI Phy
76  * page[5]: for VPLL
77  * page[6]: for DSI Link Control2
78  * page[7]: for SPI ROM mapping
79  */
80 enum page_addr_offset {
81 	PAGE0_DP_CNTL = 0,
82 	PAGE1_VDO_BDG,
83 	PAGE2_TOP_CNTL,
84 	PAGE3_DSI_CNTL1,
85 	PAGE4_MIPI_PHY,
86 	PAGE5_VPLL,
87 	PAGE6_DSI_CNTL2,
88 	PAGE7_SPI_CNTL,
89 	MAX_DEVS
90 };
91 
92 enum ps8640_vdo_control {
93 	DISABLE = VDO_DIS,
94 	ENABLE = VDO_EN,
95 };
96 
97 struct ps8640 {
98 	struct drm_bridge bridge;
99 	struct drm_bridge *panel_bridge;
100 	struct drm_dp_aux aux;
101 	struct mipi_dsi_device *dsi;
102 	struct i2c_client *page[MAX_DEVS];
103 	struct regmap	*regmap[MAX_DEVS];
104 	struct regulator_bulk_data supplies[2];
105 	struct gpio_desc *gpio_reset;
106 	struct gpio_desc *gpio_powerdown;
107 	struct device_link *link;
108 	bool pre_enabled;
109 	bool need_post_hpd_delay;
110 };
111 
112 static const struct regmap_config ps8640_regmap_config[] = {
113 	[PAGE0_DP_CNTL] = {
114 		COMMON_PS8640_REGMAP_CONFIG,
115 		.max_register = 0xbf,
116 	},
117 	[PAGE1_VDO_BDG] = {
118 		COMMON_PS8640_REGMAP_CONFIG,
119 		.max_register = 0xff,
120 	},
121 	[PAGE2_TOP_CNTL] = {
122 		COMMON_PS8640_REGMAP_CONFIG,
123 		.max_register = 0xff,
124 	},
125 	[PAGE3_DSI_CNTL1] = {
126 		COMMON_PS8640_REGMAP_CONFIG,
127 		.max_register = 0xff,
128 	},
129 	[PAGE4_MIPI_PHY] = {
130 		COMMON_PS8640_REGMAP_CONFIG,
131 		.max_register = 0xff,
132 	},
133 	[PAGE5_VPLL] = {
134 		COMMON_PS8640_REGMAP_CONFIG,
135 		.max_register = 0x7f,
136 	},
137 	[PAGE6_DSI_CNTL2] = {
138 		COMMON_PS8640_REGMAP_CONFIG,
139 		.max_register = 0xff,
140 	},
141 	[PAGE7_SPI_CNTL] = {
142 		COMMON_PS8640_REGMAP_CONFIG,
143 		.max_register = 0xff,
144 	},
145 };
146 
147 static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
148 {
149 	return container_of(e, struct ps8640, bridge);
150 }
151 
152 static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)
153 {
154 	return container_of(aux, struct ps8640, aux);
155 }
156 
157 static bool ps8640_of_panel_on_aux_bus(struct device *dev)
158 {
159 	struct device_node *bus, *panel;
160 
161 	bus = of_get_child_by_name(dev->of_node, "aux-bus");
162 	if (!bus)
163 		return false;
164 
165 	panel = of_get_child_by_name(bus, "panel");
166 	of_node_put(bus);
167 	if (!panel)
168 		return false;
169 	of_node_put(panel);
170 
171 	return true;
172 }
173 
174 static int _ps8640_wait_hpd_asserted(struct ps8640 *ps_bridge, unsigned long wait_us)
175 {
176 	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
177 	int status;
178 	int ret;
179 
180 	/*
181 	 * Apparently something about the firmware in the chip signals that
182 	 * HPD goes high by reporting GPIO9 as high (even though HPD isn't
183 	 * actually connected to GPIO9).
184 	 */
185 	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
186 				       status & PS_GPIO9, wait_us / 10, wait_us);
187 
188 	/*
189 	 * The first time we see HPD go high after a reset we delay an extra
190 	 * 50 ms. The best guess is that the MCU is doing "stuff" during this
191 	 * time (maybe talking to the panel) and we don't want to interrupt it.
192 	 *
193 	 * No locking is done around "need_post_hpd_delay". If we're here we
194 	 * know we're holding a PM Runtime reference and the only other place
195 	 * that touches this is PM Runtime resume.
196 	 */
197 	if (!ret && ps_bridge->need_post_hpd_delay) {
198 		ps_bridge->need_post_hpd_delay = false;
199 		msleep(50);
200 	}
201 
202 	return ret;
203 }
204 
205 static int ps8640_wait_hpd_asserted(struct drm_dp_aux *aux, unsigned long wait_us)
206 {
207 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
208 	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
209 	int ret;
210 
211 	/*
212 	 * Note that this function is called by code that has already powered
213 	 * the panel. We have to power ourselves up but we don't need to worry
214 	 * about powering the panel.
215 	 */
216 	pm_runtime_get_sync(dev);
217 	ret = _ps8640_wait_hpd_asserted(ps_bridge, wait_us);
218 	pm_runtime_mark_last_busy(dev);
219 	pm_runtime_put_autosuspend(dev);
220 
221 	return ret;
222 }
223 
224 static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,
225 				       struct drm_dp_aux_msg *msg)
226 {
227 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
228 	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
229 	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
230 	unsigned int len = msg->size;
231 	unsigned int data;
232 	unsigned int base;
233 	int ret;
234 	u8 request = msg->request &
235 		     ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
236 	u8 *buf = msg->buffer;
237 	u8 addr_len[PAGE0_SWAUX_LENGTH + 1 - PAGE0_SWAUX_ADDR_7_0];
238 	u8 i;
239 	bool is_native_aux = false;
240 
241 	if (len > DP_AUX_MAX_PAYLOAD_BYTES)
242 		return -EINVAL;
243 
244 	if (msg->address & ~SWAUX_ADDR_MASK)
245 		return -EINVAL;
246 
247 	switch (request) {
248 	case DP_AUX_NATIVE_WRITE:
249 	case DP_AUX_NATIVE_READ:
250 		is_native_aux = true;
251 		fallthrough;
252 	case DP_AUX_I2C_WRITE:
253 	case DP_AUX_I2C_READ:
254 		break;
255 	default:
256 		return -EINVAL;
257 	}
258 
259 	ret = regmap_write(map, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);
260 	if (ret) {
261 		DRM_DEV_ERROR(dev, "failed to write PAGE0_AUXCH_CFG3: %d\n",
262 			      ret);
263 		return ret;
264 	}
265 
266 	/* Assume it's good */
267 	msg->reply = 0;
268 
269 	base = PAGE0_SWAUX_ADDR_7_0;
270 	addr_len[PAGE0_SWAUX_ADDR_7_0 - base] = msg->address;
271 	addr_len[PAGE0_SWAUX_ADDR_15_8 - base] = msg->address >> 8;
272 	addr_len[PAGE0_SWAUX_ADDR_23_16 - base] = (msg->address >> 16) |
273 						  (msg->request << 4);
274 	addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :
275 					      ((len - 1) & SWAUX_LENGTH_MASK);
276 
277 	regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
278 			  ARRAY_SIZE(addr_len));
279 
280 	if (len && (request == DP_AUX_NATIVE_WRITE ||
281 		    request == DP_AUX_I2C_WRITE)) {
282 		/* Write to the internal FIFO buffer */
283 		for (i = 0; i < len; i++) {
284 			ret = regmap_write(map, PAGE0_SWAUX_WDATA, buf[i]);
285 			if (ret) {
286 				DRM_DEV_ERROR(dev,
287 					      "failed to write WDATA: %d\n",
288 					      ret);
289 				return ret;
290 			}
291 		}
292 	}
293 
294 	regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
295 
296 	/* Zero delay loop because i2c transactions are slow already */
297 	regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,
298 				 !(data & SWAUX_SEND), 0, 50 * 1000);
299 
300 	regmap_read(map, PAGE0_SWAUX_STATUS, &data);
301 	if (ret) {
302 		DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",
303 			      ret);
304 		return ret;
305 	}
306 
307 	switch (data & SWAUX_STATUS_MASK) {
308 	case SWAUX_STATUS_NACK:
309 	case SWAUX_STATUS_I2C_NACK:
310 		/*
311 		 * The programming guide is not clear about whether a I2C NACK
312 		 * would trigger SWAUX_STATUS_NACK or SWAUX_STATUS_I2C_NACK. So
313 		 * we handle both cases together.
314 		 */
315 		if (is_native_aux)
316 			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
317 		else
318 			msg->reply |= DP_AUX_I2C_REPLY_NACK;
319 
320 		fallthrough;
321 	case SWAUX_STATUS_ACKM:
322 		len = data & SWAUX_M_MASK;
323 		break;
324 	case SWAUX_STATUS_DEFER:
325 	case SWAUX_STATUS_I2C_DEFER:
326 		if (is_native_aux)
327 			msg->reply |= DP_AUX_NATIVE_REPLY_DEFER;
328 		else
329 			msg->reply |= DP_AUX_I2C_REPLY_DEFER;
330 		len = data & SWAUX_M_MASK;
331 		break;
332 	case SWAUX_STATUS_INVALID:
333 		return -EOPNOTSUPP;
334 	case SWAUX_STATUS_TIMEOUT:
335 		return -ETIMEDOUT;
336 	}
337 
338 	if (len && (request == DP_AUX_NATIVE_READ ||
339 		    request == DP_AUX_I2C_READ)) {
340 		/* Read from the internal FIFO buffer */
341 		for (i = 0; i < len; i++) {
342 			ret = regmap_read(map, PAGE0_SWAUX_RDATA, &data);
343 			if (ret) {
344 				DRM_DEV_ERROR(dev,
345 					      "failed to read RDATA: %d\n",
346 					      ret);
347 				return ret;
348 			}
349 
350 			buf[i] = data;
351 		}
352 	}
353 
354 	return len;
355 }
356 
357 static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
358 				   struct drm_dp_aux_msg *msg)
359 {
360 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
361 	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
362 	int ret;
363 
364 	pm_runtime_get_sync(dev);
365 	ret = ps8640_aux_transfer_msg(aux, msg);
366 	pm_runtime_mark_last_busy(dev);
367 	pm_runtime_put_autosuspend(dev);
368 
369 	return ret;
370 }
371 
372 static void ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
373 				      const enum ps8640_vdo_control ctrl)
374 {
375 	struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];
376 	struct device *dev = &ps_bridge->page[PAGE3_DSI_CNTL1]->dev;
377 	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };
378 	int ret;
379 
380 	ret = regmap_bulk_write(map, PAGE3_SET_ADD,
381 				vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
382 
383 	if (ret < 0)
384 		dev_err(dev, "failed to %sable VDO: %d\n",
385 			ctrl == ENABLE ? "en" : "dis", ret);
386 }
387 
388 static int __maybe_unused ps8640_resume(struct device *dev)
389 {
390 	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
391 	int ret;
392 
393 	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
394 				    ps_bridge->supplies);
395 	if (ret < 0) {
396 		dev_err(dev, "cannot enable regulators %d\n", ret);
397 		return ret;
398 	}
399 
400 	gpiod_set_value(ps_bridge->gpio_powerdown, 0);
401 	gpiod_set_value(ps_bridge->gpio_reset, 1);
402 	usleep_range(2000, 2500);
403 	gpiod_set_value(ps_bridge->gpio_reset, 0);
404 	/* Double reset for T4 and T5 */
405 	msleep(50);
406 	gpiod_set_value(ps_bridge->gpio_reset, 1);
407 	msleep(50);
408 	gpiod_set_value(ps_bridge->gpio_reset, 0);
409 
410 	/* We just reset things, so we need a delay after the first HPD */
411 	ps_bridge->need_post_hpd_delay = true;
412 
413 	/*
414 	 * Mystery 200 ms delay for the "MCU to be ready". It's unclear if
415 	 * this is truly necessary since the MCU will already signal that
416 	 * things are "good to go" by signaling HPD on "gpio 9". See
417 	 * _ps8640_wait_hpd_asserted(). For now we'll keep this mystery delay
418 	 * just in case.
419 	 */
420 	msleep(200);
421 
422 	return 0;
423 }
424 
425 static int __maybe_unused ps8640_suspend(struct device *dev)
426 {
427 	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
428 	int ret;
429 
430 	gpiod_set_value(ps_bridge->gpio_reset, 1);
431 	gpiod_set_value(ps_bridge->gpio_powerdown, 1);
432 	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
433 				     ps_bridge->supplies);
434 	if (ret < 0)
435 		dev_err(dev, "cannot disable regulators %d\n", ret);
436 
437 	return ret;
438 }
439 
440 static const struct dev_pm_ops ps8640_pm_ops = {
441 	SET_RUNTIME_PM_OPS(ps8640_suspend, ps8640_resume, NULL)
442 	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
443 				pm_runtime_force_resume)
444 };
445 
446 static void ps8640_atomic_pre_enable(struct drm_bridge *bridge,
447 				     struct drm_bridge_state *old_bridge_state)
448 {
449 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
450 	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
451 	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
452 	int ret;
453 
454 	pm_runtime_get_sync(dev);
455 	ret = _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000);
456 	if (ret < 0)
457 		dev_warn(dev, "HPD didn't go high: %d\n", ret);
458 
459 	/*
460 	 * The Manufacturer Command Set (MCS) is a device dependent interface
461 	 * intended for factory programming of the display module default
462 	 * parameters. Once the display module is configured, the MCS shall be
463 	 * disabled by the manufacturer. Once disabled, all MCS commands are
464 	 * ignored by the display interface.
465 	 */
466 
467 	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
468 	if (ret < 0)
469 		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
470 
471 	/* Switch access edp panel's edid through i2c */
472 	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
473 	if (ret < 0)
474 		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
475 
476 	ps8640_bridge_vdo_control(ps_bridge, ENABLE);
477 
478 	ps_bridge->pre_enabled = true;
479 }
480 
481 static void ps8640_atomic_post_disable(struct drm_bridge *bridge,
482 				       struct drm_bridge_state *old_bridge_state)
483 {
484 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
485 
486 	ps_bridge->pre_enabled = false;
487 
488 	ps8640_bridge_vdo_control(ps_bridge, DISABLE);
489 	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
490 }
491 
492 static int ps8640_bridge_attach(struct drm_bridge *bridge,
493 				enum drm_bridge_attach_flags flags)
494 {
495 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
496 	struct device *dev = &ps_bridge->page[0]->dev;
497 	int ret;
498 
499 	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
500 		return -EINVAL;
501 
502 	ps_bridge->aux.drm_dev = bridge->dev;
503 	ret = drm_dp_aux_register(&ps_bridge->aux);
504 	if (ret) {
505 		dev_err(dev, "failed to register DP AUX channel: %d\n", ret);
506 		return ret;
507 	}
508 
509 	ps_bridge->link = device_link_add(bridge->dev->dev, dev, DL_FLAG_STATELESS);
510 	if (!ps_bridge->link) {
511 		dev_err(dev, "failed to create device link");
512 		ret = -EINVAL;
513 		goto err_devlink;
514 	}
515 
516 	/* Attach the panel-bridge to the dsi bridge */
517 	ret = drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
518 				&ps_bridge->bridge, flags);
519 	if (ret)
520 		goto err_bridge_attach;
521 
522 	return 0;
523 
524 err_bridge_attach:
525 	device_link_del(ps_bridge->link);
526 err_devlink:
527 	drm_dp_aux_unregister(&ps_bridge->aux);
528 
529 	return ret;
530 }
531 
532 static void ps8640_bridge_detach(struct drm_bridge *bridge)
533 {
534 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
535 
536 	drm_dp_aux_unregister(&ps_bridge->aux);
537 	if (ps_bridge->link)
538 		device_link_del(ps_bridge->link);
539 }
540 
541 static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
542 					   struct drm_connector *connector)
543 {
544 	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
545 	bool poweroff = !ps_bridge->pre_enabled;
546 	struct edid *edid;
547 
548 	/*
549 	 * When we end calling get_edid() triggered by an ioctl, i.e
550 	 *
551 	 *   drm_mode_getconnector (ioctl)
552 	 *     -> drm_helper_probe_single_connector_modes
553 	 *        -> drm_bridge_connector_get_modes
554 	 *           -> ps8640_bridge_get_edid
555 	 *
556 	 * We need to make sure that what we need is enabled before reading
557 	 * EDID, for this chip, we need to do a full poweron, otherwise it will
558 	 * fail.
559 	 */
560 	drm_atomic_bridge_chain_pre_enable(bridge, connector->state->state);
561 
562 	edid = drm_get_edid(connector,
563 			    ps_bridge->page[PAGE0_DP_CNTL]->adapter);
564 
565 	/*
566 	 * If we call the get_edid() function without having enabled the chip
567 	 * before, return the chip to its original power state.
568 	 */
569 	if (poweroff)
570 		drm_atomic_bridge_chain_post_disable(bridge, connector->state->state);
571 
572 	return edid;
573 }
574 
575 static void ps8640_runtime_disable(void *data)
576 {
577 	pm_runtime_dont_use_autosuspend(data);
578 	pm_runtime_disable(data);
579 }
580 
581 static const struct drm_bridge_funcs ps8640_bridge_funcs = {
582 	.attach = ps8640_bridge_attach,
583 	.detach = ps8640_bridge_detach,
584 	.get_edid = ps8640_bridge_get_edid,
585 	.atomic_post_disable = ps8640_atomic_post_disable,
586 	.atomic_pre_enable = ps8640_atomic_pre_enable,
587 	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,
588 	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,
589 	.atomic_reset = drm_atomic_helper_bridge_reset,
590 };
591 
592 static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps_bridge)
593 {
594 	struct device_node *in_ep, *dsi_node;
595 	struct mipi_dsi_device *dsi;
596 	struct mipi_dsi_host *host;
597 	const struct mipi_dsi_device_info info = { .type = "ps8640",
598 						   .channel = 0,
599 						   .node = NULL,
600 						 };
601 
602 	/* port@0 is ps8640 dsi input port */
603 	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
604 	if (!in_ep)
605 		return -ENODEV;
606 
607 	dsi_node = of_graph_get_remote_port_parent(in_ep);
608 	of_node_put(in_ep);
609 	if (!dsi_node)
610 		return -ENODEV;
611 
612 	host = of_find_mipi_dsi_host_by_node(dsi_node);
613 	of_node_put(dsi_node);
614 	if (!host)
615 		return -EPROBE_DEFER;
616 
617 	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
618 	if (IS_ERR(dsi)) {
619 		dev_err(dev, "failed to create dsi device\n");
620 		return PTR_ERR(dsi);
621 	}
622 
623 	ps_bridge->dsi = dsi;
624 
625 	dsi->host = host;
626 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
627 			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
628 	dsi->format = MIPI_DSI_FMT_RGB888;
629 	dsi->lanes = NUM_MIPI_LANES;
630 
631 	return 0;
632 }
633 
634 static int ps8640_bridge_link_panel(struct drm_dp_aux *aux)
635 {
636 	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
637 	struct device *dev = aux->dev;
638 	struct device_node *np = dev->of_node;
639 	int ret;
640 
641 	/*
642 	 * NOTE about returning -EPROBE_DEFER from this function: if we
643 	 * return an error (most relevant to -EPROBE_DEFER) it will only
644 	 * be passed out to ps8640_probe() if it called this directly (AKA the
645 	 * panel isn't under the "aux-bus" node). That should be fine because
646 	 * if the panel is under "aux-bus" it's guaranteed to have probed by
647 	 * the time this function has been called.
648 	 */
649 
650 	/* port@1 is ps8640 output port */
651 	ps_bridge->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
652 	if (IS_ERR(ps_bridge->panel_bridge))
653 		return PTR_ERR(ps_bridge->panel_bridge);
654 
655 	ret = devm_drm_bridge_add(dev, &ps_bridge->bridge);
656 	if (ret)
657 		return ret;
658 
659 	return devm_mipi_dsi_attach(dev, ps_bridge->dsi);
660 }
661 
662 static int ps8640_probe(struct i2c_client *client)
663 {
664 	struct device *dev = &client->dev;
665 	struct ps8640 *ps_bridge;
666 	int ret;
667 	u32 i;
668 
669 	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
670 	if (!ps_bridge)
671 		return -ENOMEM;
672 
673 	ps_bridge->supplies[0].supply = "vdd12";
674 	ps_bridge->supplies[1].supply = "vdd33";
675 	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
676 				      ps_bridge->supplies);
677 	if (ret)
678 		return ret;
679 
680 	ps_bridge->gpio_powerdown = devm_gpiod_get(&client->dev, "powerdown",
681 						   GPIOD_OUT_HIGH);
682 	if (IS_ERR(ps_bridge->gpio_powerdown))
683 		return PTR_ERR(ps_bridge->gpio_powerdown);
684 
685 	/*
686 	 * Assert the reset to avoid the bridge being initialized prematurely
687 	 */
688 	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
689 					       GPIOD_OUT_HIGH);
690 	if (IS_ERR(ps_bridge->gpio_reset))
691 		return PTR_ERR(ps_bridge->gpio_reset);
692 
693 	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
694 	ps_bridge->bridge.of_node = dev->of_node;
695 	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
696 
697 	/*
698 	 * In the device tree, if panel is listed under aux-bus of the bridge
699 	 * node, panel driver should be able to retrieve EDID by itself using
700 	 * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here.
701 	 */
702 	if (!ps8640_of_panel_on_aux_bus(&client->dev))
703 		ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
704 
705 	/*
706 	 * Get MIPI DSI resources early. These can return -EPROBE_DEFER so
707 	 * we want to get them out of the way sooner.
708 	 */
709 	ret = ps8640_bridge_get_dsi_resources(&client->dev, ps_bridge);
710 	if (ret)
711 		return ret;
712 
713 	ps_bridge->page[PAGE0_DP_CNTL] = client;
714 
715 	ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
716 	if (IS_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]))
717 		return PTR_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]);
718 
719 	for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {
720 		ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,
721 							     client->adapter,
722 							     client->addr + i);
723 		if (IS_ERR(ps_bridge->page[i]))
724 			return PTR_ERR(ps_bridge->page[i]);
725 
726 		ps_bridge->regmap[i] = devm_regmap_init_i2c(ps_bridge->page[i],
727 							    ps8640_regmap_config + i);
728 		if (IS_ERR(ps_bridge->regmap[i]))
729 			return PTR_ERR(ps_bridge->regmap[i]);
730 	}
731 
732 	i2c_set_clientdata(client, ps_bridge);
733 
734 	ps_bridge->aux.name = "parade-ps8640-aux";
735 	ps_bridge->aux.dev = dev;
736 	ps_bridge->aux.transfer = ps8640_aux_transfer;
737 	ps_bridge->aux.wait_hpd_asserted = ps8640_wait_hpd_asserted;
738 	drm_dp_aux_init(&ps_bridge->aux);
739 
740 	pm_runtime_enable(dev);
741 	/*
742 	 * Powering on ps8640 takes ~300ms. To avoid wasting time on power
743 	 * cycling ps8640 too often, set autosuspend_delay to 2000ms to ensure
744 	 * the bridge wouldn't suspend in between each _aux_transfer_msg() call
745 	 * during EDID read (~20ms in my experiment) and in between the last
746 	 * _aux_transfer_msg() call during EDID read and the _pre_enable() call
747 	 * (~100ms in my experiment).
748 	 */
749 	pm_runtime_set_autosuspend_delay(dev, 2000);
750 	pm_runtime_use_autosuspend(dev);
751 	pm_suspend_ignore_children(dev, true);
752 	ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);
753 	if (ret)
754 		return ret;
755 
756 	ret = devm_of_dp_aux_populate_bus(&ps_bridge->aux, ps8640_bridge_link_panel);
757 
758 	/*
759 	 * If devm_of_dp_aux_populate_bus() returns -ENODEV then it's up to
760 	 * usa to call ps8640_bridge_link_panel() directly. NOTE: in this case
761 	 * the function is allowed to -EPROBE_DEFER.
762 	 */
763 	if (ret == -ENODEV)
764 		return ps8640_bridge_link_panel(&ps_bridge->aux);
765 
766 	return ret;
767 }
768 
769 static const struct of_device_id ps8640_match[] = {
770 	{ .compatible = "parade,ps8640" },
771 	{ }
772 };
773 MODULE_DEVICE_TABLE(of, ps8640_match);
774 
775 static struct i2c_driver ps8640_driver = {
776 	.probe_new = ps8640_probe,
777 	.driver = {
778 		.name = "ps8640",
779 		.of_match_table = ps8640_match,
780 		.pm = &ps8640_pm_ops,
781 	},
782 };
783 module_i2c_driver(ps8640_driver);
784 
785 MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");
786 MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");
787 MODULE_AUTHOR("Enric Balletbo i Serra <enric.balletbo@collabora.com>");
788 MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
789 MODULE_LICENSE("GPL v2");
790