Linux Audio

Check our new training course

Loading...
Note: File does not exist in v4.6.
  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_bridge.h>
 19#include <drm/drm_edid.h>
 20#include <drm/drm_mipi_dsi.h>
 21#include <drm/drm_of.h>
 22#include <drm/drm_panel.h>
 23#include <drm/drm_print.h>
 24
 25#define PAGE0_AUXCH_CFG3	0x76
 26#define  AUXCH_CFG3_RESET	0xff
 27#define PAGE0_SWAUX_ADDR_7_0	0x7d
 28#define PAGE0_SWAUX_ADDR_15_8	0x7e
 29#define PAGE0_SWAUX_ADDR_23_16	0x7f
 30#define  SWAUX_ADDR_MASK	GENMASK(19, 0)
 31#define PAGE0_SWAUX_LENGTH	0x80
 32#define  SWAUX_LENGTH_MASK	GENMASK(3, 0)
 33#define  SWAUX_NO_PAYLOAD	BIT(7)
 34#define PAGE0_SWAUX_WDATA	0x81
 35#define PAGE0_SWAUX_RDATA	0x82
 36#define PAGE0_SWAUX_CTRL	0x83
 37#define  SWAUX_SEND		BIT(0)
 38#define PAGE0_SWAUX_STATUS	0x84
 39#define  SWAUX_M_MASK		GENMASK(4, 0)
 40#define  SWAUX_STATUS_MASK	GENMASK(7, 5)
 41#define  SWAUX_STATUS_NACK	(0x1 << 5)
 42#define  SWAUX_STATUS_DEFER	(0x2 << 5)
 43#define  SWAUX_STATUS_ACKM	(0x3 << 5)
 44#define  SWAUX_STATUS_INVALID	(0x4 << 5)
 45#define  SWAUX_STATUS_I2C_NACK	(0x5 << 5)
 46#define  SWAUX_STATUS_I2C_DEFER	(0x6 << 5)
 47#define  SWAUX_STATUS_TIMEOUT	(0x7 << 5)
 48
 49#define PAGE2_GPIO_H		0xa7
 50#define  PS_GPIO9		BIT(1)
 51#define PAGE2_I2C_BYPASS	0xea
 52#define  I2C_BYPASS_EN		0xd0
 53#define PAGE2_MCS_EN		0xf3
 54#define  MCS_EN			BIT(0)
 55
 56#define PAGE3_SET_ADD		0xfe
 57#define  VDO_CTL_ADD		0x13
 58#define  VDO_DIS		0x18
 59#define  VDO_EN			0x1c
 60
 61#define NUM_MIPI_LANES		4
 62
 63#define COMMON_PS8640_REGMAP_CONFIG \
 64	.reg_bits = 8, \
 65	.val_bits = 8, \
 66	.cache_type = REGCACHE_NONE
 67
 68/*
 69 * PS8640 uses multiple addresses:
 70 * page[0]: for DP control
 71 * page[1]: for VIDEO Bridge
 72 * page[2]: for control top
 73 * page[3]: for DSI Link Control1
 74 * page[4]: for MIPI Phy
 75 * page[5]: for VPLL
 76 * page[6]: for DSI Link Control2
 77 * page[7]: for SPI ROM mapping
 78 */
 79enum page_addr_offset {
 80	PAGE0_DP_CNTL = 0,
 81	PAGE1_VDO_BDG,
 82	PAGE2_TOP_CNTL,
 83	PAGE3_DSI_CNTL1,
 84	PAGE4_MIPI_PHY,
 85	PAGE5_VPLL,
 86	PAGE6_DSI_CNTL2,
 87	PAGE7_SPI_CNTL,
 88	MAX_DEVS
 89};
 90
 91enum ps8640_vdo_control {
 92	DISABLE = VDO_DIS,
 93	ENABLE = VDO_EN,
 94};
 95
 96struct ps8640 {
 97	struct drm_bridge bridge;
 98	struct drm_bridge *panel_bridge;
 99	struct drm_dp_aux aux;
100	struct mipi_dsi_device *dsi;
101	struct i2c_client *page[MAX_DEVS];
102	struct regmap	*regmap[MAX_DEVS];
103	struct regulator_bulk_data supplies[2];
104	struct gpio_desc *gpio_reset;
105	struct gpio_desc *gpio_powerdown;
106	struct device_link *link;
107	bool pre_enabled;
108	bool need_post_hpd_delay;
109};
110
111static const struct regmap_config ps8640_regmap_config[] = {
112	[PAGE0_DP_CNTL] = {
113		COMMON_PS8640_REGMAP_CONFIG,
114		.max_register = 0xbf,
115	},
116	[PAGE1_VDO_BDG] = {
117		COMMON_PS8640_REGMAP_CONFIG,
118		.max_register = 0xff,
119	},
120	[PAGE2_TOP_CNTL] = {
121		COMMON_PS8640_REGMAP_CONFIG,
122		.max_register = 0xff,
123	},
124	[PAGE3_DSI_CNTL1] = {
125		COMMON_PS8640_REGMAP_CONFIG,
126		.max_register = 0xff,
127	},
128	[PAGE4_MIPI_PHY] = {
129		COMMON_PS8640_REGMAP_CONFIG,
130		.max_register = 0xff,
131	},
132	[PAGE5_VPLL] = {
133		COMMON_PS8640_REGMAP_CONFIG,
134		.max_register = 0x7f,
135	},
136	[PAGE6_DSI_CNTL2] = {
137		COMMON_PS8640_REGMAP_CONFIG,
138		.max_register = 0xff,
139	},
140	[PAGE7_SPI_CNTL] = {
141		COMMON_PS8640_REGMAP_CONFIG,
142		.max_register = 0xff,
143	},
144};
145
146static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
147{
148	return container_of(e, struct ps8640, bridge);
149}
150
151static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)
152{
153	return container_of(aux, struct ps8640, aux);
154}
155
156static bool ps8640_of_panel_on_aux_bus(struct device *dev)
157{
158	struct device_node *bus, *panel;
159
160	bus = of_get_child_by_name(dev->of_node, "aux-bus");
161	if (!bus)
162		return false;
163
164	panel = of_get_child_by_name(bus, "panel");
165	of_node_put(bus);
166	if (!panel)
167		return false;
168	of_node_put(panel);
169
170	return true;
171}
172
173static int _ps8640_wait_hpd_asserted(struct ps8640 *ps_bridge, unsigned long wait_us)
174{
175	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
176	int status;
177	int ret;
178
179	/*
180	 * Apparently something about the firmware in the chip signals that
181	 * HPD goes high by reporting GPIO9 as high (even though HPD isn't
182	 * actually connected to GPIO9).
183	 */
184	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
185				       status & PS_GPIO9, wait_us / 10, wait_us);
186
187	/*
188	 * The first time we see HPD go high after a reset we delay an extra
189	 * 50 ms. The best guess is that the MCU is doing "stuff" during this
190	 * time (maybe talking to the panel) and we don't want to interrupt it.
191	 *
192	 * No locking is done around "need_post_hpd_delay". If we're here we
193	 * know we're holding a PM Runtime reference and the only other place
194	 * that touches this is PM Runtime resume.
195	 */
196	if (!ret && ps_bridge->need_post_hpd_delay) {
197		ps_bridge->need_post_hpd_delay = false;
198		msleep(50);
199	}
200
201	return ret;
202}
203
204static int ps8640_wait_hpd_asserted(struct drm_dp_aux *aux, unsigned long wait_us)
205{
206	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
207	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
208	int ret;
209
210	/*
211	 * Note that this function is called by code that has already powered
212	 * the panel. We have to power ourselves up but we don't need to worry
213	 * about powering the panel.
214	 */
215	pm_runtime_get_sync(dev);
216	ret = _ps8640_wait_hpd_asserted(ps_bridge, wait_us);
217	pm_runtime_mark_last_busy(dev);
218	pm_runtime_put_autosuspend(dev);
219
220	return ret;
221}
222
223static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,
224				       struct drm_dp_aux_msg *msg)
225{
226	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
227	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
228	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
229	unsigned int len = msg->size;
230	unsigned int data;
231	unsigned int base;
232	int ret;
233	u8 request = msg->request &
234		     ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
235	u8 *buf = msg->buffer;
236	u8 addr_len[PAGE0_SWAUX_LENGTH + 1 - PAGE0_SWAUX_ADDR_7_0];
237	u8 i;
238	bool is_native_aux = false;
239
240	if (len > DP_AUX_MAX_PAYLOAD_BYTES)
241		return -EINVAL;
242
243	if (msg->address & ~SWAUX_ADDR_MASK)
244		return -EINVAL;
245
246	switch (request) {
247	case DP_AUX_NATIVE_WRITE:
248	case DP_AUX_NATIVE_READ:
249		is_native_aux = true;
250		fallthrough;
251	case DP_AUX_I2C_WRITE:
252	case DP_AUX_I2C_READ:
253		break;
254	default:
255		return -EINVAL;
256	}
257
258	ret = regmap_write(map, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);
259	if (ret) {
260		DRM_DEV_ERROR(dev, "failed to write PAGE0_AUXCH_CFG3: %d\n",
261			      ret);
262		return ret;
263	}
264
265	/* Assume it's good */
266	msg->reply = 0;
267
268	base = PAGE0_SWAUX_ADDR_7_0;
269	addr_len[PAGE0_SWAUX_ADDR_7_0 - base] = msg->address;
270	addr_len[PAGE0_SWAUX_ADDR_15_8 - base] = msg->address >> 8;
271	addr_len[PAGE0_SWAUX_ADDR_23_16 - base] = (msg->address >> 16) |
272						  (msg->request << 4);
273	addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :
274					      ((len - 1) & SWAUX_LENGTH_MASK);
275
276	regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
277			  ARRAY_SIZE(addr_len));
278
279	if (len && (request == DP_AUX_NATIVE_WRITE ||
280		    request == DP_AUX_I2C_WRITE)) {
281		/* Write to the internal FIFO buffer */
282		for (i = 0; i < len; i++) {
283			ret = regmap_write(map, PAGE0_SWAUX_WDATA, buf[i]);
284			if (ret) {
285				DRM_DEV_ERROR(dev,
286					      "failed to write WDATA: %d\n",
287					      ret);
288				return ret;
289			}
290		}
291	}
292
293	regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
294
295	/* Zero delay loop because i2c transactions are slow already */
296	regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,
297				 !(data & SWAUX_SEND), 0, 50 * 1000);
298
299	regmap_read(map, PAGE0_SWAUX_STATUS, &data);
300	if (ret) {
301		DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",
302			      ret);
303		return ret;
304	}
305
306	switch (data & SWAUX_STATUS_MASK) {
307	case SWAUX_STATUS_NACK:
308	case SWAUX_STATUS_I2C_NACK:
309		/*
310		 * The programming guide is not clear about whether a I2C NACK
311		 * would trigger SWAUX_STATUS_NACK or SWAUX_STATUS_I2C_NACK. So
312		 * we handle both cases together.
313		 */
314		if (is_native_aux)
315			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
316		else
317			msg->reply |= DP_AUX_I2C_REPLY_NACK;
318
319		fallthrough;
320	case SWAUX_STATUS_ACKM:
321		len = data & SWAUX_M_MASK;
322		break;
323	case SWAUX_STATUS_DEFER:
324	case SWAUX_STATUS_I2C_DEFER:
325		if (is_native_aux)
326			msg->reply |= DP_AUX_NATIVE_REPLY_DEFER;
327		else
328			msg->reply |= DP_AUX_I2C_REPLY_DEFER;
329		len = data & SWAUX_M_MASK;
330		break;
331	case SWAUX_STATUS_INVALID:
332		return -EOPNOTSUPP;
333	case SWAUX_STATUS_TIMEOUT:
334		return -ETIMEDOUT;
335	}
336
337	if (len && (request == DP_AUX_NATIVE_READ ||
338		    request == DP_AUX_I2C_READ)) {
339		/* Read from the internal FIFO buffer */
340		for (i = 0; i < len; i++) {
341			ret = regmap_read(map, PAGE0_SWAUX_RDATA, &data);
342			if (ret) {
343				DRM_DEV_ERROR(dev,
344					      "failed to read RDATA: %d\n",
345					      ret);
346				return ret;
347			}
348
349			buf[i] = data;
350		}
351	}
352
353	return len;
354}
355
356static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
357				   struct drm_dp_aux_msg *msg)
358{
359	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
360	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
361	int ret;
362
363	pm_runtime_get_sync(dev);
364	ret = ps8640_aux_transfer_msg(aux, msg);
365	pm_runtime_mark_last_busy(dev);
366	pm_runtime_put_autosuspend(dev);
367
368	return ret;
369}
370
371static void ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
372				      const enum ps8640_vdo_control ctrl)
373{
374	struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];
375	struct device *dev = &ps_bridge->page[PAGE3_DSI_CNTL1]->dev;
376	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };
377	int ret;
378
379	ret = regmap_bulk_write(map, PAGE3_SET_ADD,
380				vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
381
382	if (ret < 0)
383		dev_err(dev, "failed to %sable VDO: %d\n",
384			ctrl == ENABLE ? "en" : "dis", ret);
385}
386
387static int __maybe_unused ps8640_resume(struct device *dev)
388{
389	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
390	int ret;
391
392	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
393				    ps_bridge->supplies);
394	if (ret < 0) {
395		dev_err(dev, "cannot enable regulators %d\n", ret);
396		return ret;
397	}
398
399	gpiod_set_value(ps_bridge->gpio_powerdown, 0);
400	gpiod_set_value(ps_bridge->gpio_reset, 1);
401	usleep_range(2000, 2500);
402	gpiod_set_value(ps_bridge->gpio_reset, 0);
403	/* Double reset for T4 and T5 */
404	msleep(50);
405	gpiod_set_value(ps_bridge->gpio_reset, 1);
406	msleep(50);
407	gpiod_set_value(ps_bridge->gpio_reset, 0);
408
409	/* We just reset things, so we need a delay after the first HPD */
410	ps_bridge->need_post_hpd_delay = true;
411
412	/*
413	 * Mystery 200 ms delay for the "MCU to be ready". It's unclear if
414	 * this is truly necessary since the MCU will already signal that
415	 * things are "good to go" by signaling HPD on "gpio 9". See
416	 * _ps8640_wait_hpd_asserted(). For now we'll keep this mystery delay
417	 * just in case.
418	 */
419	msleep(200);
420
421	return 0;
422}
423
424static int __maybe_unused ps8640_suspend(struct device *dev)
425{
426	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
427	int ret;
428
429	gpiod_set_value(ps_bridge->gpio_reset, 1);
430	gpiod_set_value(ps_bridge->gpio_powerdown, 1);
431	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
432				     ps_bridge->supplies);
433	if (ret < 0)
434		dev_err(dev, "cannot disable regulators %d\n", ret);
435
436	return ret;
437}
438
439static const struct dev_pm_ops ps8640_pm_ops = {
440	SET_RUNTIME_PM_OPS(ps8640_suspend, ps8640_resume, NULL)
441	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
442				pm_runtime_force_resume)
443};
444
445static void ps8640_pre_enable(struct drm_bridge *bridge)
446{
447	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
448	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
449	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
450	int ret;
451
452	pm_runtime_get_sync(dev);
453	ret = _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000);
454	if (ret < 0)
455		dev_warn(dev, "HPD didn't go high: %d\n", ret);
456
457	/*
458	 * The Manufacturer Command Set (MCS) is a device dependent interface
459	 * intended for factory programming of the display module default
460	 * parameters. Once the display module is configured, the MCS shall be
461	 * disabled by the manufacturer. Once disabled, all MCS commands are
462	 * ignored by the display interface.
463	 */
464
465	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
466	if (ret < 0)
467		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
468
469	/* Switch access edp panel's edid through i2c */
470	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
471	if (ret < 0)
472		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
473
474	ps8640_bridge_vdo_control(ps_bridge, ENABLE);
475
476	ps_bridge->pre_enabled = true;
477}
478
479static void ps8640_post_disable(struct drm_bridge *bridge)
480{
481	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
482
483	ps_bridge->pre_enabled = false;
484
485	ps8640_bridge_vdo_control(ps_bridge, DISABLE);
486	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
487}
488
489static int ps8640_bridge_attach(struct drm_bridge *bridge,
490				enum drm_bridge_attach_flags flags)
491{
492	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
493	struct device *dev = &ps_bridge->page[0]->dev;
494	int ret;
495
496	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
497		return -EINVAL;
498
499	ps_bridge->aux.drm_dev = bridge->dev;
500	ret = drm_dp_aux_register(&ps_bridge->aux);
501	if (ret) {
502		dev_err(dev, "failed to register DP AUX channel: %d\n", ret);
503		return ret;
504	}
505
506	ps_bridge->link = device_link_add(bridge->dev->dev, dev, DL_FLAG_STATELESS);
507	if (!ps_bridge->link) {
508		dev_err(dev, "failed to create device link");
509		ret = -EINVAL;
510		goto err_devlink;
511	}
512
513	/* Attach the panel-bridge to the dsi bridge */
514	ret = drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
515				&ps_bridge->bridge, flags);
516	if (ret)
517		goto err_bridge_attach;
518
519	return 0;
520
521err_bridge_attach:
522	device_link_del(ps_bridge->link);
523err_devlink:
524	drm_dp_aux_unregister(&ps_bridge->aux);
525
526	return ret;
527}
528
529static void ps8640_bridge_detach(struct drm_bridge *bridge)
530{
531	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
532
533	drm_dp_aux_unregister(&ps_bridge->aux);
534	if (ps_bridge->link)
535		device_link_del(ps_bridge->link);
536}
537
538static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
539					   struct drm_connector *connector)
540{
541	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
542	bool poweroff = !ps_bridge->pre_enabled;
543	struct edid *edid;
544
545	/*
546	 * When we end calling get_edid() triggered by an ioctl, i.e
547	 *
548	 *   drm_mode_getconnector (ioctl)
549	 *     -> drm_helper_probe_single_connector_modes
550	 *        -> drm_bridge_connector_get_modes
551	 *           -> ps8640_bridge_get_edid
552	 *
553	 * We need to make sure that what we need is enabled before reading
554	 * EDID, for this chip, we need to do a full poweron, otherwise it will
555	 * fail.
556	 */
557	drm_bridge_chain_pre_enable(bridge);
558
559	edid = drm_get_edid(connector,
560			    ps_bridge->page[PAGE0_DP_CNTL]->adapter);
561
562	/*
563	 * If we call the get_edid() function without having enabled the chip
564	 * before, return the chip to its original power state.
565	 */
566	if (poweroff)
567		drm_bridge_chain_post_disable(bridge);
568
569	return edid;
570}
571
572static void ps8640_runtime_disable(void *data)
573{
574	pm_runtime_dont_use_autosuspend(data);
575	pm_runtime_disable(data);
576}
577
578static const struct drm_bridge_funcs ps8640_bridge_funcs = {
579	.attach = ps8640_bridge_attach,
580	.detach = ps8640_bridge_detach,
581	.get_edid = ps8640_bridge_get_edid,
582	.post_disable = ps8640_post_disable,
583	.pre_enable = ps8640_pre_enable,
584};
585
586static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps_bridge)
587{
588	struct device_node *in_ep, *dsi_node;
589	struct mipi_dsi_device *dsi;
590	struct mipi_dsi_host *host;
591	const struct mipi_dsi_device_info info = { .type = "ps8640",
592						   .channel = 0,
593						   .node = NULL,
594						 };
595
596	/* port@0 is ps8640 dsi input port */
597	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
598	if (!in_ep)
599		return -ENODEV;
600
601	dsi_node = of_graph_get_remote_port_parent(in_ep);
602	of_node_put(in_ep);
603	if (!dsi_node)
604		return -ENODEV;
605
606	host = of_find_mipi_dsi_host_by_node(dsi_node);
607	of_node_put(dsi_node);
608	if (!host)
609		return -EPROBE_DEFER;
610
611	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
612	if (IS_ERR(dsi)) {
613		dev_err(dev, "failed to create dsi device\n");
614		return PTR_ERR(dsi);
615	}
616
617	ps_bridge->dsi = dsi;
618
619	dsi->host = host;
620	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
621			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
622	dsi->format = MIPI_DSI_FMT_RGB888;
623	dsi->lanes = NUM_MIPI_LANES;
624
625	return 0;
626}
627
628static int ps8640_bridge_link_panel(struct drm_dp_aux *aux)
629{
630	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
631	struct device *dev = aux->dev;
632	struct device_node *np = dev->of_node;
633	int ret;
634
635	/*
636	 * NOTE about returning -EPROBE_DEFER from this function: if we
637	 * return an error (most relevant to -EPROBE_DEFER) it will only
638	 * be passed out to ps8640_probe() if it called this directly (AKA the
639	 * panel isn't under the "aux-bus" node). That should be fine because
640	 * if the panel is under "aux-bus" it's guaranteed to have probed by
641	 * the time this function has been called.
642	 */
643
644	/* port@1 is ps8640 output port */
645	ps_bridge->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
646	if (IS_ERR(ps_bridge->panel_bridge))
647		return PTR_ERR(ps_bridge->panel_bridge);
648
649	ret = devm_drm_bridge_add(dev, &ps_bridge->bridge);
650	if (ret)
651		return ret;
652
653	return devm_mipi_dsi_attach(dev, ps_bridge->dsi);
654}
655
656static int ps8640_probe(struct i2c_client *client)
657{
658	struct device *dev = &client->dev;
659	struct ps8640 *ps_bridge;
660	int ret;
661	u32 i;
662
663	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
664	if (!ps_bridge)
665		return -ENOMEM;
666
667	ps_bridge->supplies[0].supply = "vdd12";
668	ps_bridge->supplies[1].supply = "vdd33";
669	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
670				      ps_bridge->supplies);
671	if (ret)
672		return ret;
673
674	ps_bridge->gpio_powerdown = devm_gpiod_get(&client->dev, "powerdown",
675						   GPIOD_OUT_HIGH);
676	if (IS_ERR(ps_bridge->gpio_powerdown))
677		return PTR_ERR(ps_bridge->gpio_powerdown);
678
679	/*
680	 * Assert the reset to avoid the bridge being initialized prematurely
681	 */
682	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
683					       GPIOD_OUT_HIGH);
684	if (IS_ERR(ps_bridge->gpio_reset))
685		return PTR_ERR(ps_bridge->gpio_reset);
686
687	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
688	ps_bridge->bridge.of_node = dev->of_node;
689	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
690
691	/*
692	 * In the device tree, if panel is listed under aux-bus of the bridge
693	 * node, panel driver should be able to retrieve EDID by itself using
694	 * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here.
695	 */
696	if (!ps8640_of_panel_on_aux_bus(&client->dev))
697		ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
698
699	/*
700	 * Get MIPI DSI resources early. These can return -EPROBE_DEFER so
701	 * we want to get them out of the way sooner.
702	 */
703	ret = ps8640_bridge_get_dsi_resources(&client->dev, ps_bridge);
704	if (ret)
705		return ret;
706
707	ps_bridge->page[PAGE0_DP_CNTL] = client;
708
709	ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
710	if (IS_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]))
711		return PTR_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]);
712
713	for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {
714		ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,
715							     client->adapter,
716							     client->addr + i);
717		if (IS_ERR(ps_bridge->page[i]))
718			return PTR_ERR(ps_bridge->page[i]);
719
720		ps_bridge->regmap[i] = devm_regmap_init_i2c(ps_bridge->page[i],
721							    ps8640_regmap_config + i);
722		if (IS_ERR(ps_bridge->regmap[i]))
723			return PTR_ERR(ps_bridge->regmap[i]);
724	}
725
726	i2c_set_clientdata(client, ps_bridge);
727
728	ps_bridge->aux.name = "parade-ps8640-aux";
729	ps_bridge->aux.dev = dev;
730	ps_bridge->aux.transfer = ps8640_aux_transfer;
731	ps_bridge->aux.wait_hpd_asserted = ps8640_wait_hpd_asserted;
732	drm_dp_aux_init(&ps_bridge->aux);
733
734	pm_runtime_enable(dev);
735	/*
736	 * Powering on ps8640 takes ~300ms. To avoid wasting time on power
737	 * cycling ps8640 too often, set autosuspend_delay to 1000ms to ensure
738	 * the bridge wouldn't suspend in between each _aux_transfer_msg() call
739	 * during EDID read (~20ms in my experiment) and in between the last
740	 * _aux_transfer_msg() call during EDID read and the _pre_enable() call
741	 * (~100ms in my experiment).
742	 */
743	pm_runtime_set_autosuspend_delay(dev, 1000);
744	pm_runtime_use_autosuspend(dev);
745	pm_suspend_ignore_children(dev, true);
746	ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);
747	if (ret)
748		return ret;
749
750	ret = devm_of_dp_aux_populate_bus(&ps_bridge->aux, ps8640_bridge_link_panel);
751
752	/*
753	 * If devm_of_dp_aux_populate_bus() returns -ENODEV then it's up to
754	 * usa to call ps8640_bridge_link_panel() directly. NOTE: in this case
755	 * the function is allowed to -EPROBE_DEFER.
756	 */
757	if (ret == -ENODEV)
758		return ps8640_bridge_link_panel(&ps_bridge->aux);
759
760	return ret;
761}
762
763static const struct of_device_id ps8640_match[] = {
764	{ .compatible = "parade,ps8640" },
765	{ }
766};
767MODULE_DEVICE_TABLE(of, ps8640_match);
768
769static struct i2c_driver ps8640_driver = {
770	.probe_new = ps8640_probe,
771	.driver = {
772		.name = "ps8640",
773		.of_match_table = ps8640_match,
774		.pm = &ps8640_pm_ops,
775	},
776};
777module_i2c_driver(ps8640_driver);
778
779MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");
780MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");
781MODULE_AUTHOR("Enric Balletbo i Serra <enric.balletbo@collabora.com>");
782MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
783MODULE_LICENSE("GPL v2");