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1// SPDX-License-Identifier: GPL-2.0-only2/*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	0x7627#define  AUXCH_CFG3_RESET	0xff28#define PAGE0_SWAUX_ADDR_7_0	0x7d29#define PAGE0_SWAUX_ADDR_15_8	0x7e30#define PAGE0_SWAUX_ADDR_23_16	0x7f31#define  SWAUX_ADDR_MASK	GENMASK(19, 0)32#define PAGE0_SWAUX_LENGTH	0x8033#define  SWAUX_LENGTH_MASK	GENMASK(3, 0)34#define  SWAUX_NO_PAYLOAD	BIT(7)35#define PAGE0_SWAUX_WDATA	0x8136#define PAGE0_SWAUX_RDATA	0x8237#define PAGE0_SWAUX_CTRL	0x8338#define  SWAUX_SEND		BIT(0)39#define PAGE0_SWAUX_STATUS	0x8440#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		0xa751#define  PS_GPIO9		BIT(1)52#define PAGE2_I2C_BYPASS	0xea53#define  I2C_BYPASS_EN		0xd054#define PAGE2_MCS_EN		0xf355#define  MCS_EN			BIT(0)56 57#define PAGE3_SET_ADD		0xfe58#define  VDO_CTL_ADD		0x1359#define  VDO_DIS		0x1860#define  VDO_EN			0x1c61 62#define NUM_MIPI_LANES		463 64#define COMMON_PS8640_REGMAP_CONFIG \65	.reg_bits = 8, \66	.val_bits = 8, \67	.cache_type = REGCACHE_NONE68 69/*70 * PS8640 uses multiple addresses:71 * page[0]: for DP control72 * page[1]: for VIDEO Bridge73 * page[2]: for control top74 * page[3]: for DSI Link Control175 * page[4]: for MIPI Phy76 * page[5]: for VPLL77 * page[6]: for DSI Link Control278 * page[7]: for SPI ROM mapping79 */80enum 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_DEVS90};91 92enum ps8640_vdo_control {93	DISABLE = VDO_DIS,94	ENABLE = VDO_EN,95};96 97struct 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	struct mutex aux_lock;111};112 113static const struct regmap_config ps8640_regmap_config[] = {114	[PAGE0_DP_CNTL] = {115		COMMON_PS8640_REGMAP_CONFIG,116		.max_register = 0xbf,117	},118	[PAGE1_VDO_BDG] = {119		COMMON_PS8640_REGMAP_CONFIG,120		.max_register = 0xff,121	},122	[PAGE2_TOP_CNTL] = {123		COMMON_PS8640_REGMAP_CONFIG,124		.max_register = 0xff,125	},126	[PAGE3_DSI_CNTL1] = {127		COMMON_PS8640_REGMAP_CONFIG,128		.max_register = 0xff,129	},130	[PAGE4_MIPI_PHY] = {131		COMMON_PS8640_REGMAP_CONFIG,132		.max_register = 0xff,133	},134	[PAGE5_VPLL] = {135		COMMON_PS8640_REGMAP_CONFIG,136		.max_register = 0x7f,137	},138	[PAGE6_DSI_CNTL2] = {139		COMMON_PS8640_REGMAP_CONFIG,140		.max_register = 0xff,141	},142	[PAGE7_SPI_CNTL] = {143		COMMON_PS8640_REGMAP_CONFIG,144		.max_register = 0xff,145	},146};147 148static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)149{150	return container_of(e, struct ps8640, bridge);151}152 153static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)154{155	return container_of(aux, struct ps8640, aux);156}157 158static int _ps8640_wait_hpd_asserted(struct ps8640 *ps_bridge, unsigned long wait_us)159{160	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];161	int status;162	int ret;163 164	/*165	 * Apparently something about the firmware in the chip signals that166	 * HPD goes high by reporting GPIO9 as high (even though HPD isn't167	 * actually connected to GPIO9).168	 */169	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,170				       status & PS_GPIO9, 20000, wait_us);171 172	/*173	 * The first time we see HPD go high after a reset we delay an extra174	 * 50 ms. The best guess is that the MCU is doing "stuff" during this175	 * time (maybe talking to the panel) and we don't want to interrupt it.176	 *177	 * No locking is done around "need_post_hpd_delay". If we're here we178	 * know we're holding a PM Runtime reference and the only other place179	 * that touches this is PM Runtime resume.180	 */181	if (!ret && ps_bridge->need_post_hpd_delay) {182		ps_bridge->need_post_hpd_delay = false;183		msleep(50);184	}185 186	return ret;187}188 189static int ps8640_wait_hpd_asserted(struct drm_dp_aux *aux, unsigned long wait_us)190{191	struct ps8640 *ps_bridge = aux_to_ps8640(aux);192	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;193	int ret;194 195	/*196	 * Note that this function is called by code that has already powered197	 * the panel. We have to power ourselves up but we don't need to worry198	 * about powering the panel.199	 */200	pm_runtime_get_sync(dev);201	ret = _ps8640_wait_hpd_asserted(ps_bridge, wait_us);202	pm_runtime_mark_last_busy(dev);203	pm_runtime_put_autosuspend(dev);204 205	return ret;206}207 208static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,209				       struct drm_dp_aux_msg *msg)210{211	struct ps8640 *ps_bridge = aux_to_ps8640(aux);212	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];213	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;214	size_t len = msg->size;215	unsigned int data;216	unsigned int base;217	int ret;218	u8 request = msg->request &219		     ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);220	u8 *buf = msg->buffer;221	u8 addr_len[PAGE0_SWAUX_LENGTH + 1 - PAGE0_SWAUX_ADDR_7_0];222	u8 i;223	bool is_native_aux = false;224 225	if (len > DP_AUX_MAX_PAYLOAD_BYTES)226		return -EINVAL;227 228	if (msg->address & ~SWAUX_ADDR_MASK)229		return -EINVAL;230 231	switch (request) {232	case DP_AUX_NATIVE_WRITE:233	case DP_AUX_NATIVE_READ:234		is_native_aux = true;235		fallthrough;236	case DP_AUX_I2C_WRITE:237	case DP_AUX_I2C_READ:238		break;239	default:240		return -EINVAL;241	}242 243	ret = regmap_write(map, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);244	if (ret) {245		DRM_DEV_ERROR(dev, "failed to write PAGE0_AUXCH_CFG3: %d\n",246			      ret);247		return ret;248	}249 250	/* Assume it's good */251	msg->reply = 0;252 253	base = PAGE0_SWAUX_ADDR_7_0;254	addr_len[PAGE0_SWAUX_ADDR_7_0 - base] = msg->address;255	addr_len[PAGE0_SWAUX_ADDR_15_8 - base] = msg->address >> 8;256	addr_len[PAGE0_SWAUX_ADDR_23_16 - base] = (msg->address >> 16) |257						  (msg->request << 4);258	addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :259					      ((len - 1) & SWAUX_LENGTH_MASK);260 261	regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,262			  ARRAY_SIZE(addr_len));263 264	if (len && (request == DP_AUX_NATIVE_WRITE ||265		    request == DP_AUX_I2C_WRITE)) {266		/* Write to the internal FIFO buffer */267		for (i = 0; i < len; i++) {268			ret = regmap_write(map, PAGE0_SWAUX_WDATA, buf[i]);269			if (ret) {270				DRM_DEV_ERROR(dev,271					      "failed to write WDATA: %d\n",272					      ret);273				return ret;274			}275		}276	}277 278	regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);279 280	/* Zero delay loop because i2c transactions are slow already */281	regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,282				 !(data & SWAUX_SEND), 0, 50 * 1000);283 284	regmap_read(map, PAGE0_SWAUX_STATUS, &data);285	if (ret) {286		DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",287			      ret);288		return ret;289	}290 291	switch (data & SWAUX_STATUS_MASK) {292	case SWAUX_STATUS_NACK:293	case SWAUX_STATUS_I2C_NACK:294		/*295		 * The programming guide is not clear about whether a I2C NACK296		 * would trigger SWAUX_STATUS_NACK or SWAUX_STATUS_I2C_NACK. So297		 * we handle both cases together.298		 */299		if (is_native_aux)300			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;301		else302			msg->reply |= DP_AUX_I2C_REPLY_NACK;303 304		fallthrough;305	case SWAUX_STATUS_ACKM:306		len = data & SWAUX_M_MASK;307		break;308	case SWAUX_STATUS_DEFER:309	case SWAUX_STATUS_I2C_DEFER:310		if (is_native_aux)311			msg->reply |= DP_AUX_NATIVE_REPLY_DEFER;312		else313			msg->reply |= DP_AUX_I2C_REPLY_DEFER;314		len = data & SWAUX_M_MASK;315		break;316	case SWAUX_STATUS_INVALID:317		return -EOPNOTSUPP;318	case SWAUX_STATUS_TIMEOUT:319		return -ETIMEDOUT;320	}321 322	if (len && (request == DP_AUX_NATIVE_READ ||323		    request == DP_AUX_I2C_READ)) {324		/* Read from the internal FIFO buffer */325		for (i = 0; i < len; i++) {326			ret = regmap_read(map, PAGE0_SWAUX_RDATA, &data);327			if (ret) {328				DRM_DEV_ERROR(dev,329					      "failed to read RDATA: %d\n",330					      ret);331				return ret;332			}333 334			if (i < msg->size)335				buf[i] = data;336		}337	}338 339	return min(len, msg->size);340}341 342static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,343				   struct drm_dp_aux_msg *msg)344{345	struct ps8640 *ps_bridge = aux_to_ps8640(aux);346	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;347	int ret;348 349	mutex_lock(&ps_bridge->aux_lock);350	pm_runtime_get_sync(dev);351	ret = _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000);352	if (ret) {353		pm_runtime_put_sync_suspend(dev);354		goto exit;355	}356	ret = ps8640_aux_transfer_msg(aux, msg);357	pm_runtime_mark_last_busy(dev);358	pm_runtime_put_autosuspend(dev);359 360exit:361	mutex_unlock(&ps_bridge->aux_lock);362 363	return ret;364}365 366static void ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,367				      const enum ps8640_vdo_control ctrl)368{369	struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];370	struct device *dev = &ps_bridge->page[PAGE3_DSI_CNTL1]->dev;371	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };372	int ret;373 374	ret = regmap_bulk_write(map, PAGE3_SET_ADD,375				vdo_ctrl_buf, sizeof(vdo_ctrl_buf));376 377	if (ret < 0)378		dev_err(dev, "failed to %sable VDO: %d\n",379			ctrl == ENABLE ? "en" : "dis", ret);380}381 382static int __maybe_unused ps8640_resume(struct device *dev)383{384	struct ps8640 *ps_bridge = dev_get_drvdata(dev);385	int ret;386 387	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),388				    ps_bridge->supplies);389	if (ret < 0) {390		dev_err(dev, "cannot enable regulators %d\n", ret);391		return ret;392	}393 394	gpiod_set_value(ps_bridge->gpio_powerdown, 0);395	gpiod_set_value(ps_bridge->gpio_reset, 1);396	usleep_range(2000, 2500);397	gpiod_set_value(ps_bridge->gpio_reset, 0);398	/* Double reset for T4 and T5 */399	msleep(50);400	gpiod_set_value(ps_bridge->gpio_reset, 1);401	msleep(50);402	gpiod_set_value(ps_bridge->gpio_reset, 0);403 404	/* We just reset things, so we need a delay after the first HPD */405	ps_bridge->need_post_hpd_delay = true;406 407	/*408	 * Mystery 200 ms delay for the "MCU to be ready". It's unclear if409	 * this is truly necessary since the MCU will already signal that410	 * things are "good to go" by signaling HPD on "gpio 9". See411	 * _ps8640_wait_hpd_asserted(). For now we'll keep this mystery delay412	 * just in case.413	 */414	msleep(200);415 416	return 0;417}418 419static int __maybe_unused ps8640_suspend(struct device *dev)420{421	struct ps8640 *ps_bridge = dev_get_drvdata(dev);422	int ret;423 424	gpiod_set_value(ps_bridge->gpio_reset, 1);425	gpiod_set_value(ps_bridge->gpio_powerdown, 1);426	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),427				     ps_bridge->supplies);428	if (ret < 0)429		dev_err(dev, "cannot disable regulators %d\n", ret);430 431	return ret;432}433 434static const struct dev_pm_ops ps8640_pm_ops = {435	SET_RUNTIME_PM_OPS(ps8640_suspend, ps8640_resume, NULL)436	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,437				pm_runtime_force_resume)438};439 440static void ps8640_atomic_pre_enable(struct drm_bridge *bridge,441				     struct drm_bridge_state *old_bridge_state)442{443	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);444	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];445	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;446	int ret;447 448	pm_runtime_get_sync(dev);449	ret = _ps8640_wait_hpd_asserted(ps_bridge, 200 * 1000);450	if (ret < 0)451		dev_warn(dev, "HPD didn't go high: %d\n", ret);452 453	/*454	 * The Manufacturer Command Set (MCS) is a device dependent interface455	 * intended for factory programming of the display module default456	 * parameters. Once the display module is configured, the MCS shall be457	 * disabled by the manufacturer. Once disabled, all MCS commands are458	 * ignored by the display interface.459	 */460 461	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);462	if (ret < 0)463		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);464 465	/* Switch access edp panel's edid through i2c */466	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);467	if (ret < 0)468		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);469 470	ps8640_bridge_vdo_control(ps_bridge, ENABLE);471 472	ps_bridge->pre_enabled = true;473}474 475static void ps8640_atomic_post_disable(struct drm_bridge *bridge,476				       struct drm_bridge_state *old_bridge_state)477{478	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);479 480	ps_bridge->pre_enabled = false;481 482	ps8640_bridge_vdo_control(ps_bridge, DISABLE);483 484	/*485	 * The bridge seems to expect everything to be power cycled at the486	 * disable process, so grab a lock here to make sure487	 * ps8640_aux_transfer() is not holding a runtime PM reference and488	 * preventing the bridge from suspend.489	 */490	mutex_lock(&ps_bridge->aux_lock);491 492	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);493 494	mutex_unlock(&ps_bridge->aux_lock);495}496 497static int ps8640_bridge_attach(struct drm_bridge *bridge,498				enum drm_bridge_attach_flags flags)499{500	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);501	struct device *dev = &ps_bridge->page[0]->dev;502	int ret;503 504	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))505		return -EINVAL;506 507	ps_bridge->aux.drm_dev = bridge->dev;508	ret = drm_dp_aux_register(&ps_bridge->aux);509	if (ret) {510		dev_err(dev, "failed to register DP AUX channel: %d\n", ret);511		return ret;512	}513 514	ps_bridge->link = device_link_add(bridge->dev->dev, dev, DL_FLAG_STATELESS);515	if (!ps_bridge->link) {516		dev_err(dev, "failed to create device link");517		ret = -EINVAL;518		goto err_devlink;519	}520 521	/* Attach the panel-bridge to the dsi bridge */522	ret = drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,523				&ps_bridge->bridge, flags);524	if (ret)525		goto err_bridge_attach;526 527	return 0;528 529err_bridge_attach:530	device_link_del(ps_bridge->link);531err_devlink:532	drm_dp_aux_unregister(&ps_bridge->aux);533 534	return ret;535}536 537static void ps8640_bridge_detach(struct drm_bridge *bridge)538{539	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);540 541	drm_dp_aux_unregister(&ps_bridge->aux);542	if (ps_bridge->link)543		device_link_del(ps_bridge->link);544}545 546static void ps8640_runtime_disable(void *data)547{548	pm_runtime_dont_use_autosuspend(data);549	pm_runtime_disable(data);550}551 552static const struct drm_bridge_funcs ps8640_bridge_funcs = {553	.attach = ps8640_bridge_attach,554	.detach = ps8640_bridge_detach,555	.atomic_post_disable = ps8640_atomic_post_disable,556	.atomic_pre_enable = ps8640_atomic_pre_enable,557	.atomic_duplicate_state = drm_atomic_helper_bridge_duplicate_state,558	.atomic_destroy_state = drm_atomic_helper_bridge_destroy_state,559	.atomic_reset = drm_atomic_helper_bridge_reset,560};561 562static int ps8640_bridge_get_dsi_resources(struct device *dev, struct ps8640 *ps_bridge)563{564	struct device_node *in_ep, *dsi_node;565	struct mipi_dsi_device *dsi;566	struct mipi_dsi_host *host;567	const struct mipi_dsi_device_info info = { .type = "ps8640",568						   .channel = 0,569						   .node = NULL,570						 };571 572	/* port@0 is ps8640 dsi input port */573	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);574	if (!in_ep)575		return -ENODEV;576 577	dsi_node = of_graph_get_remote_port_parent(in_ep);578	of_node_put(in_ep);579	if (!dsi_node)580		return -ENODEV;581 582	host = of_find_mipi_dsi_host_by_node(dsi_node);583	of_node_put(dsi_node);584	if (!host)585		return -EPROBE_DEFER;586 587	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);588	if (IS_ERR(dsi)) {589		dev_err(dev, "failed to create dsi device\n");590		return PTR_ERR(dsi);591	}592 593	ps_bridge->dsi = dsi;594 595	dsi->host = host;596	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |597			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;598	dsi->format = MIPI_DSI_FMT_RGB888;599	dsi->lanes = NUM_MIPI_LANES;600 601	return 0;602}603 604static int ps8640_bridge_link_panel(struct drm_dp_aux *aux)605{606	struct ps8640 *ps_bridge = aux_to_ps8640(aux);607	struct device *dev = aux->dev;608	struct device_node *np = dev->of_node;609	int ret;610 611	/*612	 * NOTE about returning -EPROBE_DEFER from this function: if we613	 * return an error (most relevant to -EPROBE_DEFER) it will only614	 * be passed out to ps8640_probe() if it called this directly (AKA the615	 * panel isn't under the "aux-bus" node). That should be fine because616	 * if the panel is under "aux-bus" it's guaranteed to have probed by617	 * the time this function has been called.618	 */619 620	/* port@1 is ps8640 output port */621	ps_bridge->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);622	if (IS_ERR(ps_bridge->panel_bridge))623		return PTR_ERR(ps_bridge->panel_bridge);624 625	ret = devm_drm_bridge_add(dev, &ps_bridge->bridge);626	if (ret)627		return ret;628 629	return devm_mipi_dsi_attach(dev, ps_bridge->dsi);630}631 632static int ps8640_probe(struct i2c_client *client)633{634	struct device *dev = &client->dev;635	struct ps8640 *ps_bridge;636	int ret;637	u32 i;638 639	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);640	if (!ps_bridge)641		return -ENOMEM;642 643	mutex_init(&ps_bridge->aux_lock);644 645	ps_bridge->supplies[0].supply = "vdd12";646	ps_bridge->supplies[1].supply = "vdd33";647	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),648				      ps_bridge->supplies);649	if (ret)650		return ret;651 652	ps_bridge->gpio_powerdown = devm_gpiod_get(&client->dev, "powerdown",653						   GPIOD_OUT_HIGH);654	if (IS_ERR(ps_bridge->gpio_powerdown))655		return PTR_ERR(ps_bridge->gpio_powerdown);656 657	/*658	 * Assert the reset to avoid the bridge being initialized prematurely659	 */660	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",661					       GPIOD_OUT_HIGH);662	if (IS_ERR(ps_bridge->gpio_reset))663		return PTR_ERR(ps_bridge->gpio_reset);664 665	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;666	ps_bridge->bridge.of_node = dev->of_node;667	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;668 669	/*670	 * Get MIPI DSI resources early. These can return -EPROBE_DEFER so671	 * we want to get them out of the way sooner.672	 */673	ret = ps8640_bridge_get_dsi_resources(&client->dev, ps_bridge);674	if (ret)675		return ret;676 677	ps_bridge->page[PAGE0_DP_CNTL] = client;678 679	ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);680	if (IS_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]))681		return PTR_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]);682 683	for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {684		ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,685							     client->adapter,686							     client->addr + i);687		if (IS_ERR(ps_bridge->page[i]))688			return PTR_ERR(ps_bridge->page[i]);689 690		ps_bridge->regmap[i] = devm_regmap_init_i2c(ps_bridge->page[i],691							    ps8640_regmap_config + i);692		if (IS_ERR(ps_bridge->regmap[i]))693			return PTR_ERR(ps_bridge->regmap[i]);694	}695 696	i2c_set_clientdata(client, ps_bridge);697 698	ps_bridge->aux.name = "parade-ps8640-aux";699	ps_bridge->aux.dev = dev;700	ps_bridge->aux.transfer = ps8640_aux_transfer;701	ps_bridge->aux.wait_hpd_asserted = ps8640_wait_hpd_asserted;702	drm_dp_aux_init(&ps_bridge->aux);703 704	pm_runtime_enable(dev);705	/*706	 * Powering on ps8640 takes ~300ms. To avoid wasting time on power707	 * cycling ps8640 too often, set autosuspend_delay to 2000ms to ensure708	 * the bridge wouldn't suspend in between each _aux_transfer_msg() call709	 * during EDID read (~20ms in my experiment) and in between the last710	 * _aux_transfer_msg() call during EDID read and the _pre_enable() call711	 * (~100ms in my experiment).712	 */713	pm_runtime_set_autosuspend_delay(dev, 2000);714	pm_runtime_use_autosuspend(dev);715	pm_suspend_ignore_children(dev, true);716	ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);717	if (ret)718		return ret;719 720	ret = devm_of_dp_aux_populate_bus(&ps_bridge->aux, ps8640_bridge_link_panel);721 722	/*723	 * If devm_of_dp_aux_populate_bus() returns -ENODEV then it's up to724	 * usa to call ps8640_bridge_link_panel() directly. NOTE: in this case725	 * the function is allowed to -EPROBE_DEFER.726	 */727	if (ret == -ENODEV)728		return ps8640_bridge_link_panel(&ps_bridge->aux);729 730	return ret;731}732 733static const struct of_device_id ps8640_match[] = {734	{ .compatible = "parade,ps8640" },735	{ }736};737MODULE_DEVICE_TABLE(of, ps8640_match);738 739static struct i2c_driver ps8640_driver = {740	.probe = ps8640_probe,741	.driver = {742		.name = "ps8640",743		.of_match_table = ps8640_match,744		.pm = &ps8640_pm_ops,745	},746};747module_i2c_driver(ps8640_driver);748 749MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");750MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");751MODULE_AUTHOR("Enric Balletbo i Serra <enric.balletbo@collabora.com>");752MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");753MODULE_LICENSE("GPL v2");754