// SPDX-License-Identifier: GPL-2.0-only/* * Touch Screen driver for SiS 9200 family I2C Touch panels * * Copyright (C) 2015 SiS, Inc. * Copyright (C) 2016 Nextfour Group */ #include <linux/crc-itu-t.h>#include <linux/delay.h>#include <linux/i2c.h>#include <linux/input.h>#include <linux/input/mt.h>#include <linux/interrupt.h>#include <linux/gpio/consumer.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/unaligned.h> #define SIS_I2C_NAME		"sis_i2c_ts" /* * The I2C packet format: * le16		byte count * u8		Report ID * <contact data - variable length> * u8		Number of contacts * le16		Scan Time (optional) * le16		CRC * * One touch point information consists of 6+ bytes, the order is: * u8		contact state * u8		finger id * le16		x axis * le16		y axis * u8		contact width (optional) * u8		contact height (optional) * u8		pressure (optional) * * Maximum amount of data transmitted in one shot is 64 bytes, if controller * needs to report more contacts than fit in one packet it will send true * number of contacts in first packet and 0 as number of contacts in second * packet. */ #define SIS_MAX_PACKET_SIZE		64 #define SIS_PKT_LEN_OFFSET		0#define SIS_PKT_REPORT_OFFSET		2 /* Report ID/type */#define SIS_PKT_CONTACT_OFFSET		3 /* First contact */ #define SIS_SCAN_TIME_LEN		2 /* Supported report types */#define SIS_ALL_IN_ONE_PACKAGE		0x10#define SIS_PKT_IS_TOUCH(x)		(((x) & 0x0f) == 0x01)#define SIS_PKT_IS_HIDI2C(x)		(((x) & 0x0f) == 0x06) /* Contact properties within report */#define SIS_PKT_HAS_AREA(x)		((x) & BIT(4))#define SIS_PKT_HAS_PRESSURE(x)		((x) & BIT(5))#define SIS_PKT_HAS_SCANTIME(x)		((x) & BIT(6)) /* Contact size */#define SIS_BASE_LEN_PER_CONTACT	6#define SIS_AREA_LEN_PER_CONTACT	2#define SIS_PRESSURE_LEN_PER_CONTACT	1 /* Offsets within contact data */#define SIS_CONTACT_STATUS_OFFSET	0#define SIS_CONTACT_ID_OFFSET		1 /* Contact ID */#define SIS_CONTACT_X_OFFSET		2#define SIS_CONTACT_Y_OFFSET		4#define SIS_CONTACT_WIDTH_OFFSET	6#define SIS_CONTACT_HEIGHT_OFFSET	7#define SIS_CONTACT_PRESSURE_OFFSET(id)	(SIS_PKT_HAS_AREA(id) ? 8 : 6) /* Individual contact state */#define SIS_STATUS_UP			0x0#define SIS_STATUS_DOWN			0x3 /* Touchscreen parameters */#define SIS_MAX_FINGERS			10#define SIS_MAX_X			4095#define SIS_MAX_Y			4095#define SIS_MAX_PRESSURE		255 /* Resolution diagonal */#define SIS_AREA_LENGTH_LONGER		5792/*((SIS_MAX_X^2) + (SIS_MAX_Y^2))^0.5*/#define SIS_AREA_LENGTH_SHORT		5792#define SIS_AREA_UNIT			(5792 / 32) struct sis_ts_data {	struct i2c_client *client;	struct input_dev *input; 	struct gpio_desc *attn_gpio;	struct gpio_desc *reset_gpio; 	u8 packet[SIS_MAX_PACKET_SIZE];}; static int sis_read_packet(struct i2c_client *client, u8 *buf,			   unsigned int *num_contacts,			   unsigned int *contact_size){	int count_idx;	int ret;	u16 len;	u16 crc, pkg_crc;	u8 report_id; 	ret = i2c_master_recv(client, buf, SIS_MAX_PACKET_SIZE);	if (ret <= 0)		return -EIO; 	len = get_unaligned_le16(&buf[SIS_PKT_LEN_OFFSET]);	if (len > SIS_MAX_PACKET_SIZE) {		dev_err(&client->dev,			"%s: invalid packet length (%d vs %d)\n",			__func__, len, SIS_MAX_PACKET_SIZE);		return -E2BIG;	} 	if (len < 10)		return -EINVAL; 	report_id = buf[SIS_PKT_REPORT_OFFSET];	count_idx  = len - 1;	*contact_size = SIS_BASE_LEN_PER_CONTACT; 	if (report_id != SIS_ALL_IN_ONE_PACKAGE) {		if (SIS_PKT_IS_TOUCH(report_id)) {			/*			 * Calculate CRC ignoring packet length			 * in the beginning and CRC transmitted			 * at the end of the packet.			 */			crc = crc_itu_t(0, buf + 2, len - 2 - 2);			pkg_crc = get_unaligned_le16(&buf[len - 2]); 			if (crc != pkg_crc) {				dev_err(&client->dev,					"%s: CRC Error (%d vs %d)\n",					__func__, crc, pkg_crc);				return -EINVAL;			} 			count_idx -= 2; 		} else if (!SIS_PKT_IS_HIDI2C(report_id)) {			dev_err(&client->dev,				"%s: invalid packet ID %#02x\n",				__func__, report_id);			return -EINVAL;		} 		if (SIS_PKT_HAS_SCANTIME(report_id))			count_idx -= SIS_SCAN_TIME_LEN; 		if (SIS_PKT_HAS_AREA(report_id))			*contact_size += SIS_AREA_LEN_PER_CONTACT;		if (SIS_PKT_HAS_PRESSURE(report_id))			*contact_size += SIS_PRESSURE_LEN_PER_CONTACT;	} 	*num_contacts = buf[count_idx];	return 0;} static int sis_ts_report_contact(struct sis_ts_data *ts, const u8 *data, u8 id){	struct input_dev *input = ts->input;	int slot;	u8 status = data[SIS_CONTACT_STATUS_OFFSET];	u8 pressure;	u8 height, width;	u16 x, y; 	if (status != SIS_STATUS_DOWN && status != SIS_STATUS_UP) {		dev_err(&ts->client->dev, "Unexpected touch status: %#02x\n",			data[SIS_CONTACT_STATUS_OFFSET]);		return -EINVAL;	} 	slot = input_mt_get_slot_by_key(input, data[SIS_CONTACT_ID_OFFSET]);	if (slot < 0)		return -ENOENT; 	input_mt_slot(input, slot);	input_mt_report_slot_state(input, MT_TOOL_FINGER,				   status == SIS_STATUS_DOWN); 	if (status == SIS_STATUS_DOWN) {		pressure = height = width = 1;		if (id != SIS_ALL_IN_ONE_PACKAGE) {			if (SIS_PKT_HAS_AREA(id)) {				width = data[SIS_CONTACT_WIDTH_OFFSET];				height = data[SIS_CONTACT_HEIGHT_OFFSET];			} 			if (SIS_PKT_HAS_PRESSURE(id))				pressure =					data[SIS_CONTACT_PRESSURE_OFFSET(id)];		} 		x = get_unaligned_le16(&data[SIS_CONTACT_X_OFFSET]);		y = get_unaligned_le16(&data[SIS_CONTACT_Y_OFFSET]); 		input_report_abs(input, ABS_MT_TOUCH_MAJOR,				 width * SIS_AREA_UNIT);		input_report_abs(input, ABS_MT_TOUCH_MINOR,				 height * SIS_AREA_UNIT);		input_report_abs(input, ABS_MT_PRESSURE, pressure);		input_report_abs(input, ABS_MT_POSITION_X, x);		input_report_abs(input, ABS_MT_POSITION_Y, y);	} 	return 0;} static void sis_ts_handle_packet(struct sis_ts_data *ts){	const u8 *contact;	unsigned int num_to_report = 0;	unsigned int num_contacts;	unsigned int num_reported;	unsigned int contact_size;	int error;	u8 report_id; 	do {		error = sis_read_packet(ts->client, ts->packet,					&num_contacts, &contact_size);		if (error)			break; 		if (num_to_report == 0) {			num_to_report = num_contacts;		} else if (num_contacts != 0) {			dev_err(&ts->client->dev,				"%s: nonzero (%d) point count in tail packet\n",				__func__, num_contacts);			break;		} 		report_id = ts->packet[SIS_PKT_REPORT_OFFSET];		contact = &ts->packet[SIS_PKT_CONTACT_OFFSET];		num_reported = 0; 		while (num_to_report > 0) {			error = sis_ts_report_contact(ts, contact, report_id);			if (error)				break; 			contact += contact_size;			num_to_report--;			num_reported++; 			if (report_id != SIS_ALL_IN_ONE_PACKAGE &&			    num_reported >= 5) {				/*				 * The remainder of contacts is sent				 * in the 2nd packet.				 */				break;			}		}	} while (num_to_report > 0); 	input_mt_sync_frame(ts->input);	input_sync(ts->input);} static irqreturn_t sis_ts_irq_handler(int irq, void *dev_id){	struct sis_ts_data *ts = dev_id; 	do {		sis_ts_handle_packet(ts);	} while (ts->attn_gpio && gpiod_get_value_cansleep(ts->attn_gpio)); 	return IRQ_HANDLED;} static void sis_ts_reset(struct sis_ts_data *ts){	if (ts->reset_gpio) {		/* Get out of reset */		usleep_range(1000, 2000);		gpiod_set_value(ts->reset_gpio, 1);		usleep_range(1000, 2000);		gpiod_set_value(ts->reset_gpio, 0);		msleep(100);	}} static int sis_ts_probe(struct i2c_client *client){	struct sis_ts_data *ts;	struct input_dev *input;	int error; 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);	if (!ts)		return -ENOMEM; 	ts->client = client; 	ts->attn_gpio = devm_gpiod_get_optional(&client->dev,						"attn", GPIOD_IN);	if (IS_ERR(ts->attn_gpio))		return dev_err_probe(&client->dev, PTR_ERR(ts->attn_gpio),				     "Failed to get attention GPIO\n"); 	ts->reset_gpio = devm_gpiod_get_optional(&client->dev,						 "reset", GPIOD_OUT_LOW);	if (IS_ERR(ts->reset_gpio))		return dev_err_probe(&client->dev, PTR_ERR(ts->reset_gpio),				     "Failed to get reset GPIO\n"); 	sis_ts_reset(ts); 	ts->input = input = devm_input_allocate_device(&client->dev);	if (!input) {		dev_err(&client->dev, "Failed to allocate input device\n");		return -ENOMEM;	} 	input->name = "SiS Touchscreen";	input->id.bustype = BUS_I2C; 	input_set_abs_params(input, ABS_MT_POSITION_X, 0, SIS_MAX_X, 0, 0);	input_set_abs_params(input, ABS_MT_POSITION_Y, 0, SIS_MAX_Y, 0, 0);	input_set_abs_params(input, ABS_MT_PRESSURE, 0, SIS_MAX_PRESSURE, 0, 0);	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR,			     0, SIS_AREA_LENGTH_LONGER, 0, 0);	input_set_abs_params(input, ABS_MT_TOUCH_MINOR,			     0, SIS_AREA_LENGTH_SHORT, 0, 0); 	error = input_mt_init_slots(input, SIS_MAX_FINGERS, INPUT_MT_DIRECT);	if (error) {		dev_err(&client->dev,			"Failed to initialize MT slots: %d\n", error);		return error;	} 	error = devm_request_threaded_irq(&client->dev, client->irq,					  NULL, sis_ts_irq_handler,					  IRQF_ONESHOT,					  client->name, ts);	if (error) {		dev_err(&client->dev, "Failed to request IRQ: %d\n", error);		return error;	} 	error = input_register_device(ts->input);	if (error) {		dev_err(&client->dev,			"Failed to register input device: %d\n", error);		return error;	} 	return 0;} #ifdef CONFIG_OFstatic const struct of_device_id sis_ts_dt_ids[] = {	{ .compatible = "sis,9200-ts" },	{ /* sentinel */ }};MODULE_DEVICE_TABLE(of, sis_ts_dt_ids);#endif static const struct i2c_device_id sis_ts_id[] = {	{ .name = SIS_I2C_NAME },	{ .name = "9200-ts" },	{ /* sentinel */  }};MODULE_DEVICE_TABLE(i2c, sis_ts_id); static struct i2c_driver sis_ts_driver = {	.driver = {		.name	= SIS_I2C_NAME,		.of_match_table = of_match_ptr(sis_ts_dt_ids),	},	.probe		= sis_ts_probe,	.id_table	= sis_ts_id,};module_i2c_driver(sis_ts_driver); MODULE_DESCRIPTION("SiS 9200 Family Touchscreen Driver");MODULE_LICENSE("GPL v2");MODULE_AUTHOR("Mika Penttilä <mika.penttila@nextfour.com>");