cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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stmfts.c (20416B)


      1// SPDX-License-Identifier: GPL-2.0
      2// STMicroelectronics FTS Touchscreen device driver
      3//
      4// Copyright (c) 2017 Samsung Electronics Co., Ltd.
      5// Copyright (c) 2017 Andi Shyti <andi@etezian.org>
      6
      7#include <linux/delay.h>
      8#include <linux/i2c.h>
      9#include <linux/input/mt.h>
     10#include <linux/input/touchscreen.h>
     11#include <linux/interrupt.h>
     12#include <linux/irq.h>
     13#include <linux/leds.h>
     14#include <linux/module.h>
     15#include <linux/pm_runtime.h>
     16#include <linux/regulator/consumer.h>
     17
     18/* I2C commands */
     19#define STMFTS_READ_INFO			0x80
     20#define STMFTS_READ_STATUS			0x84
     21#define STMFTS_READ_ONE_EVENT			0x85
     22#define STMFTS_READ_ALL_EVENT			0x86
     23#define STMFTS_LATEST_EVENT			0x87
     24#define STMFTS_SLEEP_IN				0x90
     25#define STMFTS_SLEEP_OUT			0x91
     26#define STMFTS_MS_MT_SENSE_OFF			0x92
     27#define STMFTS_MS_MT_SENSE_ON			0x93
     28#define STMFTS_SS_HOVER_SENSE_OFF		0x94
     29#define STMFTS_SS_HOVER_SENSE_ON		0x95
     30#define STMFTS_MS_KEY_SENSE_OFF			0x9a
     31#define STMFTS_MS_KEY_SENSE_ON			0x9b
     32#define STMFTS_SYSTEM_RESET			0xa0
     33#define STMFTS_CLEAR_EVENT_STACK		0xa1
     34#define STMFTS_FULL_FORCE_CALIBRATION		0xa2
     35#define STMFTS_MS_CX_TUNING			0xa3
     36#define STMFTS_SS_CX_TUNING			0xa4
     37
     38/* events */
     39#define STMFTS_EV_NO_EVENT			0x00
     40#define STMFTS_EV_MULTI_TOUCH_DETECTED		0x02
     41#define STMFTS_EV_MULTI_TOUCH_ENTER		0x03
     42#define STMFTS_EV_MULTI_TOUCH_LEAVE		0x04
     43#define STMFTS_EV_MULTI_TOUCH_MOTION		0x05
     44#define STMFTS_EV_HOVER_ENTER			0x07
     45#define STMFTS_EV_HOVER_LEAVE			0x08
     46#define STMFTS_EV_HOVER_MOTION			0x09
     47#define STMFTS_EV_KEY_STATUS			0x0e
     48#define STMFTS_EV_ERROR				0x0f
     49#define STMFTS_EV_CONTROLLER_READY		0x10
     50#define STMFTS_EV_SLEEP_OUT_CONTROLLER_READY	0x11
     51#define STMFTS_EV_STATUS			0x16
     52#define STMFTS_EV_DEBUG				0xdb
     53
     54/* multi touch related event masks */
     55#define STMFTS_MASK_EVENT_ID			0x0f
     56#define STMFTS_MASK_TOUCH_ID			0xf0
     57#define STMFTS_MASK_LEFT_EVENT			0x0f
     58#define STMFTS_MASK_X_MSB			0x0f
     59#define STMFTS_MASK_Y_LSB			0xf0
     60
     61/* key related event masks */
     62#define STMFTS_MASK_KEY_NO_TOUCH		0x00
     63#define STMFTS_MASK_KEY_MENU			0x01
     64#define STMFTS_MASK_KEY_BACK			0x02
     65
     66#define STMFTS_EVENT_SIZE	8
     67#define STMFTS_STACK_DEPTH	32
     68#define STMFTS_DATA_MAX_SIZE	(STMFTS_EVENT_SIZE * STMFTS_STACK_DEPTH)
     69#define STMFTS_MAX_FINGERS	10
     70#define STMFTS_DEV_NAME		"stmfts"
     71
     72enum stmfts_regulators {
     73	STMFTS_REGULATOR_VDD,
     74	STMFTS_REGULATOR_AVDD,
     75};
     76
     77struct stmfts_data {
     78	struct i2c_client *client;
     79	struct input_dev *input;
     80	struct led_classdev led_cdev;
     81	struct mutex mutex;
     82
     83	struct touchscreen_properties prop;
     84
     85	struct regulator_bulk_data regulators[2];
     86
     87	/*
     88	 * Presence of ledvdd will be used also to check
     89	 * whether the LED is supported.
     90	 */
     91	struct regulator *ledvdd;
     92
     93	u16 chip_id;
     94	u8 chip_ver;
     95	u16 fw_ver;
     96	u8 config_id;
     97	u8 config_ver;
     98
     99	u8 data[STMFTS_DATA_MAX_SIZE];
    100
    101	struct completion cmd_done;
    102
    103	bool use_key;
    104	bool led_status;
    105	bool hover_enabled;
    106	bool running;
    107};
    108
    109static int stmfts_brightness_set(struct led_classdev *led_cdev,
    110					enum led_brightness value)
    111{
    112	struct stmfts_data *sdata = container_of(led_cdev,
    113					struct stmfts_data, led_cdev);
    114	int err;
    115
    116	if (value != sdata->led_status && sdata->ledvdd) {
    117		if (!value) {
    118			regulator_disable(sdata->ledvdd);
    119		} else {
    120			err = regulator_enable(sdata->ledvdd);
    121			if (err) {
    122				dev_warn(&sdata->client->dev,
    123					 "failed to disable ledvdd regulator: %d\n",
    124					 err);
    125				return err;
    126			}
    127		}
    128		sdata->led_status = value;
    129	}
    130
    131	return 0;
    132}
    133
    134static enum led_brightness stmfts_brightness_get(struct led_classdev *led_cdev)
    135{
    136	struct stmfts_data *sdata = container_of(led_cdev,
    137						struct stmfts_data, led_cdev);
    138
    139	return !!regulator_is_enabled(sdata->ledvdd);
    140}
    141
    142/*
    143 * We can't simply use i2c_smbus_read_i2c_block_data because we
    144 * need to read more than 255 bytes (
    145 */
    146static int stmfts_read_events(struct stmfts_data *sdata)
    147{
    148	u8 cmd = STMFTS_READ_ALL_EVENT;
    149	struct i2c_msg msgs[2] = {
    150		{
    151			.addr	= sdata->client->addr,
    152			.len	= 1,
    153			.buf	= &cmd,
    154		},
    155		{
    156			.addr	= sdata->client->addr,
    157			.flags	= I2C_M_RD,
    158			.len	= STMFTS_DATA_MAX_SIZE,
    159			.buf	= sdata->data,
    160		},
    161	};
    162	int ret;
    163
    164	ret = i2c_transfer(sdata->client->adapter, msgs, ARRAY_SIZE(msgs));
    165	if (ret < 0)
    166		return ret;
    167
    168	return ret == ARRAY_SIZE(msgs) ? 0 : -EIO;
    169}
    170
    171static void stmfts_report_contact_event(struct stmfts_data *sdata,
    172					const u8 event[])
    173{
    174	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
    175	u16 x = event[1] | ((event[2] & STMFTS_MASK_X_MSB) << 8);
    176	u16 y = (event[2] >> 4) | (event[3] << 4);
    177	u8 maj = event[4];
    178	u8 min = event[5];
    179	u8 orientation = event[6];
    180	u8 area = event[7];
    181
    182	input_mt_slot(sdata->input, slot_id);
    183
    184	input_mt_report_slot_state(sdata->input, MT_TOOL_FINGER, true);
    185	input_report_abs(sdata->input, ABS_MT_POSITION_X, x);
    186	input_report_abs(sdata->input, ABS_MT_POSITION_Y, y);
    187	input_report_abs(sdata->input, ABS_MT_TOUCH_MAJOR, maj);
    188	input_report_abs(sdata->input, ABS_MT_TOUCH_MINOR, min);
    189	input_report_abs(sdata->input, ABS_MT_PRESSURE, area);
    190	input_report_abs(sdata->input, ABS_MT_ORIENTATION, orientation);
    191
    192	input_sync(sdata->input);
    193}
    194
    195static void stmfts_report_contact_release(struct stmfts_data *sdata,
    196					  const u8 event[])
    197{
    198	u8 slot_id = (event[0] & STMFTS_MASK_TOUCH_ID) >> 4;
    199
    200	input_mt_slot(sdata->input, slot_id);
    201	input_mt_report_slot_inactive(sdata->input);
    202
    203	input_sync(sdata->input);
    204}
    205
    206static void stmfts_report_hover_event(struct stmfts_data *sdata,
    207				      const u8 event[])
    208{
    209	u16 x = (event[2] << 4) | (event[4] >> 4);
    210	u16 y = (event[3] << 4) | (event[4] & STMFTS_MASK_Y_LSB);
    211	u8 z = event[5];
    212
    213	input_report_abs(sdata->input, ABS_X, x);
    214	input_report_abs(sdata->input, ABS_Y, y);
    215	input_report_abs(sdata->input, ABS_DISTANCE, z);
    216
    217	input_sync(sdata->input);
    218}
    219
    220static void stmfts_report_key_event(struct stmfts_data *sdata, const u8 event[])
    221{
    222	switch (event[2]) {
    223	case 0:
    224		input_report_key(sdata->input, KEY_BACK, 0);
    225		input_report_key(sdata->input, KEY_MENU, 0);
    226		break;
    227
    228	case STMFTS_MASK_KEY_BACK:
    229		input_report_key(sdata->input, KEY_BACK, 1);
    230		break;
    231
    232	case STMFTS_MASK_KEY_MENU:
    233		input_report_key(sdata->input, KEY_MENU, 1);
    234		break;
    235
    236	default:
    237		dev_warn(&sdata->client->dev,
    238			 "unknown key event: %#02x\n", event[2]);
    239		break;
    240	}
    241
    242	input_sync(sdata->input);
    243}
    244
    245static void stmfts_parse_events(struct stmfts_data *sdata)
    246{
    247	int i;
    248
    249	for (i = 0; i < STMFTS_STACK_DEPTH; i++) {
    250		u8 *event = &sdata->data[i * STMFTS_EVENT_SIZE];
    251
    252		switch (event[0]) {
    253
    254		case STMFTS_EV_CONTROLLER_READY:
    255		case STMFTS_EV_SLEEP_OUT_CONTROLLER_READY:
    256		case STMFTS_EV_STATUS:
    257			complete(&sdata->cmd_done);
    258			fallthrough;
    259
    260		case STMFTS_EV_NO_EVENT:
    261		case STMFTS_EV_DEBUG:
    262			return;
    263		}
    264
    265		switch (event[0] & STMFTS_MASK_EVENT_ID) {
    266
    267		case STMFTS_EV_MULTI_TOUCH_ENTER:
    268		case STMFTS_EV_MULTI_TOUCH_MOTION:
    269			stmfts_report_contact_event(sdata, event);
    270			break;
    271
    272		case STMFTS_EV_MULTI_TOUCH_LEAVE:
    273			stmfts_report_contact_release(sdata, event);
    274			break;
    275
    276		case STMFTS_EV_HOVER_ENTER:
    277		case STMFTS_EV_HOVER_LEAVE:
    278		case STMFTS_EV_HOVER_MOTION:
    279			stmfts_report_hover_event(sdata, event);
    280			break;
    281
    282		case STMFTS_EV_KEY_STATUS:
    283			stmfts_report_key_event(sdata, event);
    284			break;
    285
    286		case STMFTS_EV_ERROR:
    287			dev_warn(&sdata->client->dev,
    288					"error code: 0x%x%x%x%x%x%x",
    289					event[6], event[5], event[4],
    290					event[3], event[2], event[1]);
    291			break;
    292
    293		default:
    294			dev_err(&sdata->client->dev,
    295				"unknown event %#02x\n", event[0]);
    296		}
    297	}
    298}
    299
    300static irqreturn_t stmfts_irq_handler(int irq, void *dev)
    301{
    302	struct stmfts_data *sdata = dev;
    303	int err;
    304
    305	mutex_lock(&sdata->mutex);
    306
    307	err = stmfts_read_events(sdata);
    308	if (unlikely(err))
    309		dev_err(&sdata->client->dev,
    310			"failed to read events: %d\n", err);
    311	else
    312		stmfts_parse_events(sdata);
    313
    314	mutex_unlock(&sdata->mutex);
    315	return IRQ_HANDLED;
    316}
    317
    318static int stmfts_command(struct stmfts_data *sdata, const u8 cmd)
    319{
    320	int err;
    321
    322	reinit_completion(&sdata->cmd_done);
    323
    324	err = i2c_smbus_write_byte(sdata->client, cmd);
    325	if (err)
    326		return err;
    327
    328	if (!wait_for_completion_timeout(&sdata->cmd_done,
    329					 msecs_to_jiffies(1000)))
    330		return -ETIMEDOUT;
    331
    332	return 0;
    333}
    334
    335static int stmfts_input_open(struct input_dev *dev)
    336{
    337	struct stmfts_data *sdata = input_get_drvdata(dev);
    338	int err;
    339
    340	err = pm_runtime_resume_and_get(&sdata->client->dev);
    341	if (err)
    342		return err;
    343
    344	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_ON);
    345	if (err) {
    346		pm_runtime_put_sync(&sdata->client->dev);
    347		return err;
    348	}
    349
    350	mutex_lock(&sdata->mutex);
    351	sdata->running = true;
    352
    353	if (sdata->hover_enabled) {
    354		err = i2c_smbus_write_byte(sdata->client,
    355					   STMFTS_SS_HOVER_SENSE_ON);
    356		if (err)
    357			dev_warn(&sdata->client->dev,
    358				 "failed to enable hover\n");
    359	}
    360	mutex_unlock(&sdata->mutex);
    361
    362	if (sdata->use_key) {
    363		err = i2c_smbus_write_byte(sdata->client,
    364					   STMFTS_MS_KEY_SENSE_ON);
    365		if (err)
    366			/* I can still use only the touch screen */
    367			dev_warn(&sdata->client->dev,
    368				 "failed to enable touchkey\n");
    369	}
    370
    371	return 0;
    372}
    373
    374static void stmfts_input_close(struct input_dev *dev)
    375{
    376	struct stmfts_data *sdata = input_get_drvdata(dev);
    377	int err;
    378
    379	err = i2c_smbus_write_byte(sdata->client, STMFTS_MS_MT_SENSE_OFF);
    380	if (err)
    381		dev_warn(&sdata->client->dev,
    382			 "failed to disable touchscreen: %d\n", err);
    383
    384	mutex_lock(&sdata->mutex);
    385
    386	sdata->running = false;
    387
    388	if (sdata->hover_enabled) {
    389		err = i2c_smbus_write_byte(sdata->client,
    390					   STMFTS_SS_HOVER_SENSE_OFF);
    391		if (err)
    392			dev_warn(&sdata->client->dev,
    393				 "failed to disable hover: %d\n", err);
    394	}
    395	mutex_unlock(&sdata->mutex);
    396
    397	if (sdata->use_key) {
    398		err = i2c_smbus_write_byte(sdata->client,
    399					   STMFTS_MS_KEY_SENSE_OFF);
    400		if (err)
    401			dev_warn(&sdata->client->dev,
    402				 "failed to disable touchkey: %d\n", err);
    403	}
    404
    405	pm_runtime_put_sync(&sdata->client->dev);
    406}
    407
    408static ssize_t stmfts_sysfs_chip_id(struct device *dev,
    409				struct device_attribute *attr, char *buf)
    410{
    411	struct stmfts_data *sdata = dev_get_drvdata(dev);
    412
    413	return sprintf(buf, "%#x\n", sdata->chip_id);
    414}
    415
    416static ssize_t stmfts_sysfs_chip_version(struct device *dev,
    417				struct device_attribute *attr, char *buf)
    418{
    419	struct stmfts_data *sdata = dev_get_drvdata(dev);
    420
    421	return sprintf(buf, "%u\n", sdata->chip_ver);
    422}
    423
    424static ssize_t stmfts_sysfs_fw_ver(struct device *dev,
    425				struct device_attribute *attr, char *buf)
    426{
    427	struct stmfts_data *sdata = dev_get_drvdata(dev);
    428
    429	return sprintf(buf, "%u\n", sdata->fw_ver);
    430}
    431
    432static ssize_t stmfts_sysfs_config_id(struct device *dev,
    433				struct device_attribute *attr, char *buf)
    434{
    435	struct stmfts_data *sdata = dev_get_drvdata(dev);
    436
    437	return sprintf(buf, "%#x\n", sdata->config_id);
    438}
    439
    440static ssize_t stmfts_sysfs_config_version(struct device *dev,
    441				struct device_attribute *attr, char *buf)
    442{
    443	struct stmfts_data *sdata = dev_get_drvdata(dev);
    444
    445	return sprintf(buf, "%u\n", sdata->config_ver);
    446}
    447
    448static ssize_t stmfts_sysfs_read_status(struct device *dev,
    449				struct device_attribute *attr, char *buf)
    450{
    451	struct stmfts_data *sdata = dev_get_drvdata(dev);
    452	u8 status[4];
    453	int err;
    454
    455	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_STATUS,
    456					    sizeof(status), status);
    457	if (err)
    458		return err;
    459
    460	return sprintf(buf, "%#02x\n", status[0]);
    461}
    462
    463static ssize_t stmfts_sysfs_hover_enable_read(struct device *dev,
    464				struct device_attribute *attr, char *buf)
    465{
    466	struct stmfts_data *sdata = dev_get_drvdata(dev);
    467
    468	return sprintf(buf, "%u\n", sdata->hover_enabled);
    469}
    470
    471static ssize_t stmfts_sysfs_hover_enable_write(struct device *dev,
    472				struct device_attribute *attr,
    473				const char *buf, size_t len)
    474{
    475	struct stmfts_data *sdata = dev_get_drvdata(dev);
    476	unsigned long value;
    477	int err = 0;
    478
    479	if (kstrtoul(buf, 0, &value))
    480		return -EINVAL;
    481
    482	mutex_lock(&sdata->mutex);
    483
    484	if (value && sdata->hover_enabled)
    485		goto out;
    486
    487	if (sdata->running)
    488		err = i2c_smbus_write_byte(sdata->client,
    489					   value ? STMFTS_SS_HOVER_SENSE_ON :
    490						   STMFTS_SS_HOVER_SENSE_OFF);
    491
    492	if (!err)
    493		sdata->hover_enabled = !!value;
    494
    495out:
    496	mutex_unlock(&sdata->mutex);
    497
    498	return len;
    499}
    500
    501static DEVICE_ATTR(chip_id, 0444, stmfts_sysfs_chip_id, NULL);
    502static DEVICE_ATTR(chip_version, 0444, stmfts_sysfs_chip_version, NULL);
    503static DEVICE_ATTR(fw_ver, 0444, stmfts_sysfs_fw_ver, NULL);
    504static DEVICE_ATTR(config_id, 0444, stmfts_sysfs_config_id, NULL);
    505static DEVICE_ATTR(config_version, 0444, stmfts_sysfs_config_version, NULL);
    506static DEVICE_ATTR(status, 0444, stmfts_sysfs_read_status, NULL);
    507static DEVICE_ATTR(hover_enable, 0644, stmfts_sysfs_hover_enable_read,
    508					stmfts_sysfs_hover_enable_write);
    509
    510static struct attribute *stmfts_sysfs_attrs[] = {
    511	&dev_attr_chip_id.attr,
    512	&dev_attr_chip_version.attr,
    513	&dev_attr_fw_ver.attr,
    514	&dev_attr_config_id.attr,
    515	&dev_attr_config_version.attr,
    516	&dev_attr_status.attr,
    517	&dev_attr_hover_enable.attr,
    518	NULL
    519};
    520
    521static struct attribute_group stmfts_attribute_group = {
    522	.attrs = stmfts_sysfs_attrs
    523};
    524
    525static int stmfts_power_on(struct stmfts_data *sdata)
    526{
    527	int err;
    528	u8 reg[8];
    529
    530	err = regulator_bulk_enable(ARRAY_SIZE(sdata->regulators),
    531				    sdata->regulators);
    532	if (err)
    533		return err;
    534
    535	/*
    536	 * The datasheet does not specify the power on time, but considering
    537	 * that the reset time is < 10ms, I sleep 20ms to be sure
    538	 */
    539	msleep(20);
    540
    541	err = i2c_smbus_read_i2c_block_data(sdata->client, STMFTS_READ_INFO,
    542					    sizeof(reg), reg);
    543	if (err < 0)
    544		return err;
    545	if (err != sizeof(reg))
    546		return -EIO;
    547
    548	sdata->chip_id = be16_to_cpup((__be16 *)&reg[6]);
    549	sdata->chip_ver = reg[0];
    550	sdata->fw_ver = be16_to_cpup((__be16 *)&reg[2]);
    551	sdata->config_id = reg[4];
    552	sdata->config_ver = reg[5];
    553
    554	enable_irq(sdata->client->irq);
    555
    556	msleep(50);
    557
    558	err = stmfts_command(sdata, STMFTS_SYSTEM_RESET);
    559	if (err)
    560		return err;
    561
    562	err = stmfts_command(sdata, STMFTS_SLEEP_OUT);
    563	if (err)
    564		return err;
    565
    566	/* optional tuning */
    567	err = stmfts_command(sdata, STMFTS_MS_CX_TUNING);
    568	if (err)
    569		dev_warn(&sdata->client->dev,
    570			 "failed to perform mutual auto tune: %d\n", err);
    571
    572	/* optional tuning */
    573	err = stmfts_command(sdata, STMFTS_SS_CX_TUNING);
    574	if (err)
    575		dev_warn(&sdata->client->dev,
    576			 "failed to perform self auto tune: %d\n", err);
    577
    578	err = stmfts_command(sdata, STMFTS_FULL_FORCE_CALIBRATION);
    579	if (err)
    580		return err;
    581
    582	/*
    583	 * At this point no one is using the touchscreen
    584	 * and I don't really care about the return value
    585	 */
    586	(void) i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
    587
    588	return 0;
    589}
    590
    591static void stmfts_power_off(void *data)
    592{
    593	struct stmfts_data *sdata = data;
    594
    595	disable_irq(sdata->client->irq);
    596	regulator_bulk_disable(ARRAY_SIZE(sdata->regulators),
    597						sdata->regulators);
    598}
    599
    600/* This function is void because I don't want to prevent using the touch key
    601 * only because the LEDs don't get registered
    602 */
    603static int stmfts_enable_led(struct stmfts_data *sdata)
    604{
    605	int err;
    606
    607	/* get the regulator for powering the leds on */
    608	sdata->ledvdd = devm_regulator_get(&sdata->client->dev, "ledvdd");
    609	if (IS_ERR(sdata->ledvdd))
    610		return PTR_ERR(sdata->ledvdd);
    611
    612	sdata->led_cdev.name = STMFTS_DEV_NAME;
    613	sdata->led_cdev.max_brightness = LED_ON;
    614	sdata->led_cdev.brightness = LED_OFF;
    615	sdata->led_cdev.brightness_set_blocking = stmfts_brightness_set;
    616	sdata->led_cdev.brightness_get = stmfts_brightness_get;
    617
    618	err = devm_led_classdev_register(&sdata->client->dev, &sdata->led_cdev);
    619	if (err) {
    620		devm_regulator_put(sdata->ledvdd);
    621		return err;
    622	}
    623
    624	return 0;
    625}
    626
    627static int stmfts_probe(struct i2c_client *client,
    628			const struct i2c_device_id *id)
    629{
    630	int err;
    631	struct stmfts_data *sdata;
    632
    633	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C |
    634						I2C_FUNC_SMBUS_BYTE_DATA |
    635						I2C_FUNC_SMBUS_I2C_BLOCK))
    636		return -ENODEV;
    637
    638	sdata = devm_kzalloc(&client->dev, sizeof(*sdata), GFP_KERNEL);
    639	if (!sdata)
    640		return -ENOMEM;
    641
    642	i2c_set_clientdata(client, sdata);
    643
    644	sdata->client = client;
    645	mutex_init(&sdata->mutex);
    646	init_completion(&sdata->cmd_done);
    647
    648	sdata->regulators[STMFTS_REGULATOR_VDD].supply = "vdd";
    649	sdata->regulators[STMFTS_REGULATOR_AVDD].supply = "avdd";
    650	err = devm_regulator_bulk_get(&client->dev,
    651				      ARRAY_SIZE(sdata->regulators),
    652				      sdata->regulators);
    653	if (err)
    654		return err;
    655
    656	sdata->input = devm_input_allocate_device(&client->dev);
    657	if (!sdata->input)
    658		return -ENOMEM;
    659
    660	sdata->input->name = STMFTS_DEV_NAME;
    661	sdata->input->id.bustype = BUS_I2C;
    662	sdata->input->open = stmfts_input_open;
    663	sdata->input->close = stmfts_input_close;
    664
    665	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_X);
    666	input_set_capability(sdata->input, EV_ABS, ABS_MT_POSITION_Y);
    667	touchscreen_parse_properties(sdata->input, true, &sdata->prop);
    668
    669	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
    670	input_set_abs_params(sdata->input, ABS_MT_TOUCH_MINOR, 0, 255, 0, 0);
    671	input_set_abs_params(sdata->input, ABS_MT_ORIENTATION, 0, 255, 0, 0);
    672	input_set_abs_params(sdata->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
    673	input_set_abs_params(sdata->input, ABS_DISTANCE, 0, 255, 0, 0);
    674
    675	sdata->use_key = device_property_read_bool(&client->dev,
    676						   "touch-key-connected");
    677	if (sdata->use_key) {
    678		input_set_capability(sdata->input, EV_KEY, KEY_MENU);
    679		input_set_capability(sdata->input, EV_KEY, KEY_BACK);
    680	}
    681
    682	err = input_mt_init_slots(sdata->input,
    683				  STMFTS_MAX_FINGERS, INPUT_MT_DIRECT);
    684	if (err)
    685		return err;
    686
    687	input_set_drvdata(sdata->input, sdata);
    688
    689	/*
    690	 * stmfts_power_on expects interrupt to be disabled, but
    691	 * at this point the device is still off and I do not trust
    692	 * the status of the irq line that can generate some spurious
    693	 * interrupts. To be on the safe side it's better to not enable
    694	 * the interrupts during their request.
    695	 */
    696	err = devm_request_threaded_irq(&client->dev, client->irq,
    697					NULL, stmfts_irq_handler,
    698					IRQF_ONESHOT | IRQF_NO_AUTOEN,
    699					"stmfts_irq", sdata);
    700	if (err)
    701		return err;
    702
    703	dev_dbg(&client->dev, "initializing ST-Microelectronics FTS...\n");
    704
    705	err = stmfts_power_on(sdata);
    706	if (err)
    707		return err;
    708
    709	err = devm_add_action_or_reset(&client->dev, stmfts_power_off, sdata);
    710	if (err)
    711		return err;
    712
    713	err = input_register_device(sdata->input);
    714	if (err)
    715		return err;
    716
    717	if (sdata->use_key) {
    718		err = stmfts_enable_led(sdata);
    719		if (err) {
    720			/*
    721			 * Even if the LEDs have failed to be initialized and
    722			 * used in the driver, I can still use the device even
    723			 * without LEDs. The ledvdd regulator pointer will be
    724			 * used as a flag.
    725			 */
    726			dev_warn(&client->dev, "unable to use touchkey leds\n");
    727			sdata->ledvdd = NULL;
    728		}
    729	}
    730
    731	err = devm_device_add_group(&client->dev, &stmfts_attribute_group);
    732	if (err)
    733		return err;
    734
    735	pm_runtime_enable(&client->dev);
    736	device_enable_async_suspend(&client->dev);
    737
    738	return 0;
    739}
    740
    741static int stmfts_remove(struct i2c_client *client)
    742{
    743	pm_runtime_disable(&client->dev);
    744
    745	return 0;
    746}
    747
    748static int __maybe_unused stmfts_runtime_suspend(struct device *dev)
    749{
    750	struct stmfts_data *sdata = dev_get_drvdata(dev);
    751	int ret;
    752
    753	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_IN);
    754	if (ret)
    755		dev_warn(dev, "failed to suspend device: %d\n", ret);
    756
    757	return ret;
    758}
    759
    760static int __maybe_unused stmfts_runtime_resume(struct device *dev)
    761{
    762	struct stmfts_data *sdata = dev_get_drvdata(dev);
    763	int ret;
    764
    765	ret = i2c_smbus_write_byte(sdata->client, STMFTS_SLEEP_OUT);
    766	if (ret)
    767		dev_err(dev, "failed to resume device: %d\n", ret);
    768
    769	return ret;
    770}
    771
    772static int __maybe_unused stmfts_suspend(struct device *dev)
    773{
    774	struct stmfts_data *sdata = dev_get_drvdata(dev);
    775
    776	stmfts_power_off(sdata);
    777
    778	return 0;
    779}
    780
    781static int __maybe_unused stmfts_resume(struct device *dev)
    782{
    783	struct stmfts_data *sdata = dev_get_drvdata(dev);
    784
    785	return stmfts_power_on(sdata);
    786}
    787
    788static const struct dev_pm_ops stmfts_pm_ops = {
    789	SET_SYSTEM_SLEEP_PM_OPS(stmfts_suspend, stmfts_resume)
    790	SET_RUNTIME_PM_OPS(stmfts_runtime_suspend, stmfts_runtime_resume, NULL)
    791};
    792
    793#ifdef CONFIG_OF
    794static const struct of_device_id stmfts_of_match[] = {
    795	{ .compatible = "st,stmfts", },
    796	{ },
    797};
    798MODULE_DEVICE_TABLE(of, stmfts_of_match);
    799#endif
    800
    801static const struct i2c_device_id stmfts_id[] = {
    802	{ "stmfts", 0 },
    803	{ },
    804};
    805MODULE_DEVICE_TABLE(i2c, stmfts_id);
    806
    807static struct i2c_driver stmfts_driver = {
    808	.driver = {
    809		.name = STMFTS_DEV_NAME,
    810		.of_match_table = of_match_ptr(stmfts_of_match),
    811		.pm = &stmfts_pm_ops,
    812		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
    813	},
    814	.probe = stmfts_probe,
    815	.remove = stmfts_remove,
    816	.id_table = stmfts_id,
    817};
    818
    819module_i2c_driver(stmfts_driver);
    820
    821MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
    822MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
    823MODULE_LICENSE("GPL v2");