cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

parade-ps8640.c (18965B)


      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_mipi_dsi.h>
     20#include <drm/drm_of.h>
     21#include <drm/drm_panel.h>
     22#include <drm/drm_print.h>
     23
     24#define PAGE0_AUXCH_CFG3	0x76
     25#define  AUXCH_CFG3_RESET	0xff
     26#define PAGE0_SWAUX_ADDR_7_0	0x7d
     27#define PAGE0_SWAUX_ADDR_15_8	0x7e
     28#define PAGE0_SWAUX_ADDR_23_16	0x7f
     29#define  SWAUX_ADDR_MASK	GENMASK(19, 0)
     30#define PAGE0_SWAUX_LENGTH	0x80
     31#define  SWAUX_LENGTH_MASK	GENMASK(3, 0)
     32#define  SWAUX_NO_PAYLOAD	BIT(7)
     33#define PAGE0_SWAUX_WDATA	0x81
     34#define PAGE0_SWAUX_RDATA	0x82
     35#define PAGE0_SWAUX_CTRL	0x83
     36#define  SWAUX_SEND		BIT(0)
     37#define PAGE0_SWAUX_STATUS	0x84
     38#define  SWAUX_M_MASK		GENMASK(4, 0)
     39#define  SWAUX_STATUS_MASK	GENMASK(7, 5)
     40#define  SWAUX_STATUS_NACK	(0x1 << 5)
     41#define  SWAUX_STATUS_DEFER	(0x2 << 5)
     42#define  SWAUX_STATUS_ACKM	(0x3 << 5)
     43#define  SWAUX_STATUS_INVALID	(0x4 << 5)
     44#define  SWAUX_STATUS_I2C_NACK	(0x5 << 5)
     45#define  SWAUX_STATUS_I2C_DEFER	(0x6 << 5)
     46#define  SWAUX_STATUS_TIMEOUT	(0x7 << 5)
     47
     48#define PAGE2_GPIO_H		0xa7
     49#define  PS_GPIO9		BIT(1)
     50#define PAGE2_I2C_BYPASS	0xea
     51#define  I2C_BYPASS_EN		0xd0
     52#define PAGE2_MCS_EN		0xf3
     53#define  MCS_EN			BIT(0)
     54
     55#define PAGE3_SET_ADD		0xfe
     56#define  VDO_CTL_ADD		0x13
     57#define  VDO_DIS		0x18
     58#define  VDO_EN			0x1c
     59
     60#define NUM_MIPI_LANES		4
     61
     62#define COMMON_PS8640_REGMAP_CONFIG \
     63	.reg_bits = 8, \
     64	.val_bits = 8, \
     65	.cache_type = REGCACHE_NONE
     66
     67/*
     68 * PS8640 uses multiple addresses:
     69 * page[0]: for DP control
     70 * page[1]: for VIDEO Bridge
     71 * page[2]: for control top
     72 * page[3]: for DSI Link Control1
     73 * page[4]: for MIPI Phy
     74 * page[5]: for VPLL
     75 * page[6]: for DSI Link Control2
     76 * page[7]: for SPI ROM mapping
     77 */
     78enum page_addr_offset {
     79	PAGE0_DP_CNTL = 0,
     80	PAGE1_VDO_BDG,
     81	PAGE2_TOP_CNTL,
     82	PAGE3_DSI_CNTL1,
     83	PAGE4_MIPI_PHY,
     84	PAGE5_VPLL,
     85	PAGE6_DSI_CNTL2,
     86	PAGE7_SPI_CNTL,
     87	MAX_DEVS
     88};
     89
     90enum ps8640_vdo_control {
     91	DISABLE = VDO_DIS,
     92	ENABLE = VDO_EN,
     93};
     94
     95struct ps8640 {
     96	struct drm_bridge bridge;
     97	struct drm_bridge *panel_bridge;
     98	struct drm_dp_aux aux;
     99	struct mipi_dsi_device *dsi;
    100	struct i2c_client *page[MAX_DEVS];
    101	struct regmap	*regmap[MAX_DEVS];
    102	struct regulator_bulk_data supplies[2];
    103	struct gpio_desc *gpio_reset;
    104	struct gpio_desc *gpio_powerdown;
    105	struct device_link *link;
    106	bool pre_enabled;
    107};
    108
    109static const struct regmap_config ps8640_regmap_config[] = {
    110	[PAGE0_DP_CNTL] = {
    111		COMMON_PS8640_REGMAP_CONFIG,
    112		.max_register = 0xbf,
    113	},
    114	[PAGE1_VDO_BDG] = {
    115		COMMON_PS8640_REGMAP_CONFIG,
    116		.max_register = 0xff,
    117	},
    118	[PAGE2_TOP_CNTL] = {
    119		COMMON_PS8640_REGMAP_CONFIG,
    120		.max_register = 0xff,
    121	},
    122	[PAGE3_DSI_CNTL1] = {
    123		COMMON_PS8640_REGMAP_CONFIG,
    124		.max_register = 0xff,
    125	},
    126	[PAGE4_MIPI_PHY] = {
    127		COMMON_PS8640_REGMAP_CONFIG,
    128		.max_register = 0xff,
    129	},
    130	[PAGE5_VPLL] = {
    131		COMMON_PS8640_REGMAP_CONFIG,
    132		.max_register = 0x7f,
    133	},
    134	[PAGE6_DSI_CNTL2] = {
    135		COMMON_PS8640_REGMAP_CONFIG,
    136		.max_register = 0xff,
    137	},
    138	[PAGE7_SPI_CNTL] = {
    139		COMMON_PS8640_REGMAP_CONFIG,
    140		.max_register = 0xff,
    141	},
    142};
    143
    144static inline struct ps8640 *bridge_to_ps8640(struct drm_bridge *e)
    145{
    146	return container_of(e, struct ps8640, bridge);
    147}
    148
    149static inline struct ps8640 *aux_to_ps8640(struct drm_dp_aux *aux)
    150{
    151	return container_of(aux, struct ps8640, aux);
    152}
    153
    154static bool ps8640_of_panel_on_aux_bus(struct device *dev)
    155{
    156	struct device_node *bus, *panel;
    157
    158	bus = of_get_child_by_name(dev->of_node, "aux-bus");
    159	if (!bus)
    160		return false;
    161
    162	panel = of_get_child_by_name(bus, "panel");
    163	of_node_put(bus);
    164	if (!panel)
    165		return false;
    166	of_node_put(panel);
    167
    168	return true;
    169}
    170
    171static int ps8640_ensure_hpd(struct ps8640 *ps_bridge)
    172{
    173	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
    174	struct device *dev = &ps_bridge->page[PAGE2_TOP_CNTL]->dev;
    175	int status;
    176	int ret;
    177
    178	/*
    179	 * Apparently something about the firmware in the chip signals that
    180	 * HPD goes high by reporting GPIO9 as high (even though HPD isn't
    181	 * actually connected to GPIO9).
    182	 */
    183	ret = regmap_read_poll_timeout(map, PAGE2_GPIO_H, status,
    184				       status & PS_GPIO9, 20 * 1000, 200 * 1000);
    185
    186	if (ret < 0)
    187		dev_warn(dev, "HPD didn't go high: %d\n", ret);
    188
    189	return ret;
    190}
    191
    192static ssize_t ps8640_aux_transfer_msg(struct drm_dp_aux *aux,
    193				       struct drm_dp_aux_msg *msg)
    194{
    195	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
    196	struct regmap *map = ps_bridge->regmap[PAGE0_DP_CNTL];
    197	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
    198	unsigned int len = msg->size;
    199	unsigned int data;
    200	unsigned int base;
    201	int ret;
    202	u8 request = msg->request &
    203		     ~(DP_AUX_I2C_MOT | DP_AUX_I2C_WRITE_STATUS_UPDATE);
    204	u8 *buf = msg->buffer;
    205	u8 addr_len[PAGE0_SWAUX_LENGTH + 1 - PAGE0_SWAUX_ADDR_7_0];
    206	u8 i;
    207	bool is_native_aux = false;
    208
    209	if (len > DP_AUX_MAX_PAYLOAD_BYTES)
    210		return -EINVAL;
    211
    212	if (msg->address & ~SWAUX_ADDR_MASK)
    213		return -EINVAL;
    214
    215	switch (request) {
    216	case DP_AUX_NATIVE_WRITE:
    217	case DP_AUX_NATIVE_READ:
    218		is_native_aux = true;
    219		fallthrough;
    220	case DP_AUX_I2C_WRITE:
    221	case DP_AUX_I2C_READ:
    222		break;
    223	default:
    224		return -EINVAL;
    225	}
    226
    227	ret = regmap_write(map, PAGE0_AUXCH_CFG3, AUXCH_CFG3_RESET);
    228	if (ret) {
    229		DRM_DEV_ERROR(dev, "failed to write PAGE0_AUXCH_CFG3: %d\n",
    230			      ret);
    231		return ret;
    232	}
    233
    234	/* Assume it's good */
    235	msg->reply = 0;
    236
    237	base = PAGE0_SWAUX_ADDR_7_0;
    238	addr_len[PAGE0_SWAUX_ADDR_7_0 - base] = msg->address;
    239	addr_len[PAGE0_SWAUX_ADDR_15_8 - base] = msg->address >> 8;
    240	addr_len[PAGE0_SWAUX_ADDR_23_16 - base] = (msg->address >> 16) |
    241						  (msg->request << 4);
    242	addr_len[PAGE0_SWAUX_LENGTH - base] = (len == 0) ? SWAUX_NO_PAYLOAD :
    243					      ((len - 1) & SWAUX_LENGTH_MASK);
    244
    245	regmap_bulk_write(map, PAGE0_SWAUX_ADDR_7_0, addr_len,
    246			  ARRAY_SIZE(addr_len));
    247
    248	if (len && (request == DP_AUX_NATIVE_WRITE ||
    249		    request == DP_AUX_I2C_WRITE)) {
    250		/* Write to the internal FIFO buffer */
    251		for (i = 0; i < len; i++) {
    252			ret = regmap_write(map, PAGE0_SWAUX_WDATA, buf[i]);
    253			if (ret) {
    254				DRM_DEV_ERROR(dev,
    255					      "failed to write WDATA: %d\n",
    256					      ret);
    257				return ret;
    258			}
    259		}
    260	}
    261
    262	regmap_write(map, PAGE0_SWAUX_CTRL, SWAUX_SEND);
    263
    264	/* Zero delay loop because i2c transactions are slow already */
    265	regmap_read_poll_timeout(map, PAGE0_SWAUX_CTRL, data,
    266				 !(data & SWAUX_SEND), 0, 50 * 1000);
    267
    268	regmap_read(map, PAGE0_SWAUX_STATUS, &data);
    269	if (ret) {
    270		DRM_DEV_ERROR(dev, "failed to read PAGE0_SWAUX_STATUS: %d\n",
    271			      ret);
    272		return ret;
    273	}
    274
    275	switch (data & SWAUX_STATUS_MASK) {
    276	/* Ignore the DEFER cases as they are already handled in hardware */
    277	case SWAUX_STATUS_NACK:
    278	case SWAUX_STATUS_I2C_NACK:
    279		/*
    280		 * The programming guide is not clear about whether a I2C NACK
    281		 * would trigger SWAUX_STATUS_NACK or SWAUX_STATUS_I2C_NACK. So
    282		 * we handle both cases together.
    283		 */
    284		if (is_native_aux)
    285			msg->reply |= DP_AUX_NATIVE_REPLY_NACK;
    286		else
    287			msg->reply |= DP_AUX_I2C_REPLY_NACK;
    288
    289		fallthrough;
    290	case SWAUX_STATUS_ACKM:
    291		len = data & SWAUX_M_MASK;
    292		break;
    293	case SWAUX_STATUS_INVALID:
    294		return -EOPNOTSUPP;
    295	case SWAUX_STATUS_TIMEOUT:
    296		return -ETIMEDOUT;
    297	}
    298
    299	if (len && (request == DP_AUX_NATIVE_READ ||
    300		    request == DP_AUX_I2C_READ)) {
    301		/* Read from the internal FIFO buffer */
    302		for (i = 0; i < len; i++) {
    303			ret = regmap_read(map, PAGE0_SWAUX_RDATA, &data);
    304			if (ret) {
    305				DRM_DEV_ERROR(dev,
    306					      "failed to read RDATA: %d\n",
    307					      ret);
    308				return ret;
    309			}
    310
    311			buf[i] = data;
    312		}
    313	}
    314
    315	return len;
    316}
    317
    318static ssize_t ps8640_aux_transfer(struct drm_dp_aux *aux,
    319				   struct drm_dp_aux_msg *msg)
    320{
    321	struct ps8640 *ps_bridge = aux_to_ps8640(aux);
    322	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
    323	int ret;
    324
    325	pm_runtime_get_sync(dev);
    326	ret = ps8640_ensure_hpd(ps_bridge);
    327	if (!ret)
    328		ret = ps8640_aux_transfer_msg(aux, msg);
    329	pm_runtime_mark_last_busy(dev);
    330	pm_runtime_put_autosuspend(dev);
    331
    332	return ret;
    333}
    334
    335static void ps8640_bridge_vdo_control(struct ps8640 *ps_bridge,
    336				      const enum ps8640_vdo_control ctrl)
    337{
    338	struct regmap *map = ps_bridge->regmap[PAGE3_DSI_CNTL1];
    339	struct device *dev = &ps_bridge->page[PAGE3_DSI_CNTL1]->dev;
    340	u8 vdo_ctrl_buf[] = { VDO_CTL_ADD, ctrl };
    341	int ret;
    342
    343	ret = regmap_bulk_write(map, PAGE3_SET_ADD,
    344				vdo_ctrl_buf, sizeof(vdo_ctrl_buf));
    345
    346	if (ret < 0)
    347		dev_err(dev, "failed to %sable VDO: %d\n",
    348			ctrl == ENABLE ? "en" : "dis", ret);
    349}
    350
    351static int __maybe_unused ps8640_resume(struct device *dev)
    352{
    353	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
    354	int ret;
    355
    356	ret = regulator_bulk_enable(ARRAY_SIZE(ps_bridge->supplies),
    357				    ps_bridge->supplies);
    358	if (ret < 0) {
    359		dev_err(dev, "cannot enable regulators %d\n", ret);
    360		return ret;
    361	}
    362
    363	gpiod_set_value(ps_bridge->gpio_powerdown, 0);
    364	gpiod_set_value(ps_bridge->gpio_reset, 1);
    365	usleep_range(2000, 2500);
    366	gpiod_set_value(ps_bridge->gpio_reset, 0);
    367
    368	/*
    369	 * Mystery 200 ms delay for the "MCU to be ready". It's unclear if
    370	 * this is truly necessary since the MCU will already signal that
    371	 * things are "good to go" by signaling HPD on "gpio 9". See
    372	 * ps8640_ensure_hpd(). For now we'll keep this mystery delay just in
    373	 * case.
    374	 */
    375	msleep(200);
    376
    377	return 0;
    378}
    379
    380static int __maybe_unused ps8640_suspend(struct device *dev)
    381{
    382	struct ps8640 *ps_bridge = dev_get_drvdata(dev);
    383	int ret;
    384
    385	gpiod_set_value(ps_bridge->gpio_reset, 1);
    386	gpiod_set_value(ps_bridge->gpio_powerdown, 1);
    387	ret = regulator_bulk_disable(ARRAY_SIZE(ps_bridge->supplies),
    388				     ps_bridge->supplies);
    389	if (ret < 0)
    390		dev_err(dev, "cannot disable regulators %d\n", ret);
    391
    392	return ret;
    393}
    394
    395static const struct dev_pm_ops ps8640_pm_ops = {
    396	SET_RUNTIME_PM_OPS(ps8640_suspend, ps8640_resume, NULL)
    397	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
    398				pm_runtime_force_resume)
    399};
    400
    401static void ps8640_pre_enable(struct drm_bridge *bridge)
    402{
    403	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
    404	struct regmap *map = ps_bridge->regmap[PAGE2_TOP_CNTL];
    405	struct device *dev = &ps_bridge->page[PAGE0_DP_CNTL]->dev;
    406	int ret;
    407
    408	pm_runtime_get_sync(dev);
    409	ps8640_ensure_hpd(ps_bridge);
    410
    411	/*
    412	 * The Manufacturer Command Set (MCS) is a device dependent interface
    413	 * intended for factory programming of the display module default
    414	 * parameters. Once the display module is configured, the MCS shall be
    415	 * disabled by the manufacturer. Once disabled, all MCS commands are
    416	 * ignored by the display interface.
    417	 */
    418
    419	ret = regmap_update_bits(map, PAGE2_MCS_EN, MCS_EN, 0);
    420	if (ret < 0)
    421		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
    422
    423	/* Switch access edp panel's edid through i2c */
    424	ret = regmap_write(map, PAGE2_I2C_BYPASS, I2C_BYPASS_EN);
    425	if (ret < 0)
    426		dev_warn(dev, "failed write PAGE2_MCS_EN: %d\n", ret);
    427
    428	ps8640_bridge_vdo_control(ps_bridge, ENABLE);
    429
    430	ps_bridge->pre_enabled = true;
    431}
    432
    433static void ps8640_post_disable(struct drm_bridge *bridge)
    434{
    435	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
    436
    437	ps_bridge->pre_enabled = false;
    438
    439	ps8640_bridge_vdo_control(ps_bridge, DISABLE);
    440	pm_runtime_put_sync_suspend(&ps_bridge->page[PAGE0_DP_CNTL]->dev);
    441}
    442
    443static int ps8640_bridge_attach(struct drm_bridge *bridge,
    444				enum drm_bridge_attach_flags flags)
    445{
    446	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
    447	struct device *dev = &ps_bridge->page[0]->dev;
    448	int ret;
    449
    450	if (!(flags & DRM_BRIDGE_ATTACH_NO_CONNECTOR))
    451		return -EINVAL;
    452
    453	ps_bridge->aux.drm_dev = bridge->dev;
    454	ret = drm_dp_aux_register(&ps_bridge->aux);
    455	if (ret) {
    456		dev_err(dev, "failed to register DP AUX channel: %d\n", ret);
    457		return ret;
    458	}
    459
    460	ps_bridge->link = device_link_add(bridge->dev->dev, dev, DL_FLAG_STATELESS);
    461	if (!ps_bridge->link) {
    462		dev_err(dev, "failed to create device link");
    463		ret = -EINVAL;
    464		goto err_devlink;
    465	}
    466
    467	/* Attach the panel-bridge to the dsi bridge */
    468	ret = drm_bridge_attach(bridge->encoder, ps_bridge->panel_bridge,
    469				&ps_bridge->bridge, flags);
    470	if (ret)
    471		goto err_bridge_attach;
    472
    473	return 0;
    474
    475err_bridge_attach:
    476	device_link_del(ps_bridge->link);
    477err_devlink:
    478	drm_dp_aux_unregister(&ps_bridge->aux);
    479
    480	return ret;
    481}
    482
    483static void ps8640_bridge_detach(struct drm_bridge *bridge)
    484{
    485	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
    486
    487	drm_dp_aux_unregister(&ps_bridge->aux);
    488	if (ps_bridge->link)
    489		device_link_del(ps_bridge->link);
    490}
    491
    492static struct edid *ps8640_bridge_get_edid(struct drm_bridge *bridge,
    493					   struct drm_connector *connector)
    494{
    495	struct ps8640 *ps_bridge = bridge_to_ps8640(bridge);
    496	bool poweroff = !ps_bridge->pre_enabled;
    497	struct edid *edid;
    498
    499	/*
    500	 * When we end calling get_edid() triggered by an ioctl, i.e
    501	 *
    502	 *   drm_mode_getconnector (ioctl)
    503	 *     -> drm_helper_probe_single_connector_modes
    504	 *        -> drm_bridge_connector_get_modes
    505	 *           -> ps8640_bridge_get_edid
    506	 *
    507	 * We need to make sure that what we need is enabled before reading
    508	 * EDID, for this chip, we need to do a full poweron, otherwise it will
    509	 * fail.
    510	 */
    511	drm_bridge_chain_pre_enable(bridge);
    512
    513	edid = drm_get_edid(connector,
    514			    ps_bridge->page[PAGE0_DP_CNTL]->adapter);
    515
    516	/*
    517	 * If we call the get_edid() function without having enabled the chip
    518	 * before, return the chip to its original power state.
    519	 */
    520	if (poweroff)
    521		drm_bridge_chain_post_disable(bridge);
    522
    523	return edid;
    524}
    525
    526static void ps8640_runtime_disable(void *data)
    527{
    528	pm_runtime_dont_use_autosuspend(data);
    529	pm_runtime_disable(data);
    530}
    531
    532static const struct drm_bridge_funcs ps8640_bridge_funcs = {
    533	.attach = ps8640_bridge_attach,
    534	.detach = ps8640_bridge_detach,
    535	.get_edid = ps8640_bridge_get_edid,
    536	.post_disable = ps8640_post_disable,
    537	.pre_enable = ps8640_pre_enable,
    538};
    539
    540static int ps8640_bridge_host_attach(struct device *dev, struct ps8640 *ps_bridge)
    541{
    542	struct device_node *in_ep, *dsi_node;
    543	struct mipi_dsi_device *dsi;
    544	struct mipi_dsi_host *host;
    545	int ret;
    546	const struct mipi_dsi_device_info info = { .type = "ps8640",
    547						   .channel = 0,
    548						   .node = NULL,
    549						 };
    550
    551	/* port@0 is ps8640 dsi input port */
    552	in_ep = of_graph_get_endpoint_by_regs(dev->of_node, 0, -1);
    553	if (!in_ep)
    554		return -ENODEV;
    555
    556	dsi_node = of_graph_get_remote_port_parent(in_ep);
    557	of_node_put(in_ep);
    558	if (!dsi_node)
    559		return -ENODEV;
    560
    561	host = of_find_mipi_dsi_host_by_node(dsi_node);
    562	of_node_put(dsi_node);
    563	if (!host)
    564		return -EPROBE_DEFER;
    565
    566	dsi = devm_mipi_dsi_device_register_full(dev, host, &info);
    567	if (IS_ERR(dsi)) {
    568		dev_err(dev, "failed to create dsi device\n");
    569		return PTR_ERR(dsi);
    570	}
    571
    572	ps_bridge->dsi = dsi;
    573
    574	dsi->host = host;
    575	dsi->mode_flags = MIPI_DSI_MODE_VIDEO |
    576			  MIPI_DSI_MODE_VIDEO_SYNC_PULSE;
    577	dsi->format = MIPI_DSI_FMT_RGB888;
    578	dsi->lanes = NUM_MIPI_LANES;
    579
    580	ret = devm_mipi_dsi_attach(dev, dsi);
    581	if (ret)
    582		return ret;
    583
    584	return 0;
    585}
    586
    587static int ps8640_probe(struct i2c_client *client)
    588{
    589	struct device *dev = &client->dev;
    590	struct device_node *np = dev->of_node;
    591	struct ps8640 *ps_bridge;
    592	int ret;
    593	u32 i;
    594
    595	ps_bridge = devm_kzalloc(dev, sizeof(*ps_bridge), GFP_KERNEL);
    596	if (!ps_bridge)
    597		return -ENOMEM;
    598
    599	ps_bridge->supplies[0].supply = "vdd33";
    600	ps_bridge->supplies[1].supply = "vdd12";
    601	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ps_bridge->supplies),
    602				      ps_bridge->supplies);
    603	if (ret)
    604		return ret;
    605
    606	ps_bridge->gpio_powerdown = devm_gpiod_get(&client->dev, "powerdown",
    607						   GPIOD_OUT_HIGH);
    608	if (IS_ERR(ps_bridge->gpio_powerdown))
    609		return PTR_ERR(ps_bridge->gpio_powerdown);
    610
    611	/*
    612	 * Assert the reset to avoid the bridge being initialized prematurely
    613	 */
    614	ps_bridge->gpio_reset = devm_gpiod_get(&client->dev, "reset",
    615					       GPIOD_OUT_HIGH);
    616	if (IS_ERR(ps_bridge->gpio_reset))
    617		return PTR_ERR(ps_bridge->gpio_reset);
    618
    619	ps_bridge->bridge.funcs = &ps8640_bridge_funcs;
    620	ps_bridge->bridge.of_node = dev->of_node;
    621	ps_bridge->bridge.type = DRM_MODE_CONNECTOR_eDP;
    622
    623	/*
    624	 * In the device tree, if panel is listed under aux-bus of the bridge
    625	 * node, panel driver should be able to retrieve EDID by itself using
    626	 * aux-bus. So let's not set DRM_BRIDGE_OP_EDID here.
    627	 */
    628	if (!ps8640_of_panel_on_aux_bus(&client->dev))
    629		ps_bridge->bridge.ops = DRM_BRIDGE_OP_EDID;
    630
    631	ps_bridge->page[PAGE0_DP_CNTL] = client;
    632
    633	ps_bridge->regmap[PAGE0_DP_CNTL] = devm_regmap_init_i2c(client, ps8640_regmap_config);
    634	if (IS_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]))
    635		return PTR_ERR(ps_bridge->regmap[PAGE0_DP_CNTL]);
    636
    637	for (i = 1; i < ARRAY_SIZE(ps_bridge->page); i++) {
    638		ps_bridge->page[i] = devm_i2c_new_dummy_device(&client->dev,
    639							     client->adapter,
    640							     client->addr + i);
    641		if (IS_ERR(ps_bridge->page[i]))
    642			return PTR_ERR(ps_bridge->page[i]);
    643
    644		ps_bridge->regmap[i] = devm_regmap_init_i2c(ps_bridge->page[i],
    645							    ps8640_regmap_config + i);
    646		if (IS_ERR(ps_bridge->regmap[i]))
    647			return PTR_ERR(ps_bridge->regmap[i]);
    648	}
    649
    650	i2c_set_clientdata(client, ps_bridge);
    651
    652	ps_bridge->aux.name = "parade-ps8640-aux";
    653	ps_bridge->aux.dev = dev;
    654	ps_bridge->aux.transfer = ps8640_aux_transfer;
    655	drm_dp_aux_init(&ps_bridge->aux);
    656
    657	pm_runtime_enable(dev);
    658	/*
    659	 * Powering on ps8640 takes ~300ms. To avoid wasting time on power
    660	 * cycling ps8640 too often, set autosuspend_delay to 1000ms to ensure
    661	 * the bridge wouldn't suspend in between each _aux_transfer_msg() call
    662	 * during EDID read (~20ms in my experiment) and in between the last
    663	 * _aux_transfer_msg() call during EDID read and the _pre_enable() call
    664	 * (~100ms in my experiment).
    665	 */
    666	pm_runtime_set_autosuspend_delay(dev, 1000);
    667	pm_runtime_use_autosuspend(dev);
    668	pm_suspend_ignore_children(dev, true);
    669	ret = devm_add_action_or_reset(dev, ps8640_runtime_disable, dev);
    670	if (ret)
    671		return ret;
    672
    673	devm_of_dp_aux_populate_ep_devices(&ps_bridge->aux);
    674
    675	/* port@1 is ps8640 output port */
    676	ps_bridge->panel_bridge = devm_drm_of_get_bridge(dev, np, 1, 0);
    677	if (IS_ERR(ps_bridge->panel_bridge))
    678		return PTR_ERR(ps_bridge->panel_bridge);
    679
    680	drm_bridge_add(&ps_bridge->bridge);
    681
    682	ret = ps8640_bridge_host_attach(dev, ps_bridge);
    683	if (ret)
    684		goto err_bridge_remove;
    685
    686	return 0;
    687
    688err_bridge_remove:
    689	drm_bridge_remove(&ps_bridge->bridge);
    690	return ret;
    691}
    692
    693static int ps8640_remove(struct i2c_client *client)
    694{
    695	struct ps8640 *ps_bridge = i2c_get_clientdata(client);
    696
    697	drm_bridge_remove(&ps_bridge->bridge);
    698
    699	return 0;
    700}
    701
    702static const struct of_device_id ps8640_match[] = {
    703	{ .compatible = "parade,ps8640" },
    704	{ }
    705};
    706MODULE_DEVICE_TABLE(of, ps8640_match);
    707
    708static struct i2c_driver ps8640_driver = {
    709	.probe_new = ps8640_probe,
    710	.remove = ps8640_remove,
    711	.driver = {
    712		.name = "ps8640",
    713		.of_match_table = ps8640_match,
    714		.pm = &ps8640_pm_ops,
    715	},
    716};
    717module_i2c_driver(ps8640_driver);
    718
    719MODULE_AUTHOR("Jitao Shi <jitao.shi@mediatek.com>");
    720MODULE_AUTHOR("CK Hu <ck.hu@mediatek.com>");
    721MODULE_AUTHOR("Enric Balletbo i Serra <enric.balletbo@collabora.com>");
    722MODULE_DESCRIPTION("PARADE ps8640 DSI-eDP converter driver");
    723MODULE_LICENSE("GPL v2");