drivers/input/touchscreen/elo.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Elo serial touchscreen driver
  *
  * Copyright (c) 2004 Vojtech Pavlik
  */


 /*
  * This driver can handle serial Elo touchscreens using either the Elo standard
  * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo
  * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol.
  */

 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/input.h>
 #include <linux/serio.h>
 #include <linux/ctype.h>

 #define DRIVER_DESC	"Elo serial touchscreen driver"

 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
 MODULE_DESCRIPTION(DRIVER_DESC);
 MODULE_LICENSE("GPL");

 /*
  * Definitions & global arrays.
  */

 #define ELO_MAX_LENGTH		10

 #define ELO10_PACKET_LEN	8
 #define ELO10_TOUCH		0x03
 #define ELO10_PRESSURE		0x80

 #define ELO10_LEAD_BYTE		'U'

 #define ELO10_ID_CMD		'i'

 #define ELO10_TOUCH_PACKET	'T'
 #define ELO10_ACK_PACKET	'A'
 #define ELI10_ID_PACKET		'I'

 /*
  * Per-touchscreen data.
  */

 struct elo {
 	struct input_dev *dev;
 	struct serio *serio;
 	struct mutex cmd_mutex;
 	struct completion cmd_done;
 	int id;
 	int idx;
 	unsigned char expected_packet;
 	unsigned char csum;
 	unsigned char data[ELO_MAX_LENGTH];
 	unsigned char response[ELO10_PACKET_LEN];
 	char phys[32];
 };

 static void elo_process_data_10(struct elo *elo, unsigned char data)
 {
 	struct input_dev *dev = elo->dev;

 	elo->data[elo->idx] = data;

 	switch (elo->idx++) {
 	case 0:
 		elo->csum = 0xaa;
 		if (data != ELO10_LEAD_BYTE) {
 			dev_dbg(&elo->serio->dev,
 				"unsynchronized data: 0x%02x\n", data);
 			elo->idx = 0;
 		}
 		break;

 	case 9:
 		elo->idx = 0;
 		if (data != elo->csum) {
 			dev_dbg(&elo->serio->dev,
 				"bad checksum: 0x%02x, expected 0x%02x\n",
 				 data, elo->csum);
 			break;
 		}
 		if (elo->data[1] != elo->expected_packet) {
 			if (elo->data[1] != ELO10_TOUCH_PACKET)
 				dev_dbg(&elo->serio->dev,
 					"unexpected packet: 0x%02x\n",
 					 elo->data[1]);
 			break;
 		}
 		if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
 			input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
 			input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
 			if (elo->data[2] & ELO10_PRESSURE)
 				input_report_abs(dev, ABS_PRESSURE,
 						(elo->data[8] << 8) | elo->data[7]);
 			input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
 			input_sync(dev);
 		} else if (elo->data[1] == ELO10_ACK_PACKET) {
 			if (elo->data[2] == '0')
 				elo->expected_packet = ELO10_TOUCH_PACKET;
 			complete(&elo->cmd_done);
 		} else {
 			memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
 			elo->expected_packet = ELO10_ACK_PACKET;
 		}
 		break;
 	}
 	elo->csum += data;
 }

 static void elo_process_data_6(struct elo *elo, unsigned char data)
 {
 	struct input_dev *dev = elo->dev;

 	elo->data[elo->idx] = data;

 	switch (elo->idx++) {

 	case 0:
 		if ((data & 0xc0) != 0xc0)
 			elo->idx = 0;
 		break;

 	case 1:
 		if ((data & 0xc0) != 0x80)
 			elo->idx = 0;
 		break;

 	case 2:
 		if ((data & 0xc0) != 0x40)
 			elo->idx = 0;
 		break;

 	case 3:
 		if (data & 0xc0) {
 			elo->idx = 0;
 			break;
 		}

 		input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
 		input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));

 		if (elo->id == 2) {
 			input_report_key(dev, BTN_TOUCH, 1);
 			input_sync(dev);
 			elo->idx = 0;
 		}

 		break;

 	case 4:
 		if (data) {
 			input_sync(dev);
 			elo->idx = 0;
 		}
 		break;

 	case 5:
 		if ((data & 0xf0) == 0) {
 			input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
 			input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
 		}
 		input_sync(dev);
 		elo->idx = 0;
 		break;
 	}
 }

 static void elo_process_data_3(struct elo *elo, unsigned char data)
 {
 	struct input_dev *dev = elo->dev;

 	elo->data[elo->idx] = data;

 	switch (elo->idx++) {

 	case 0:
 		if ((data & 0x7f) != 0x01)
 			elo->idx = 0;
 		break;
 	case 2:
 		input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
 		input_report_abs(dev, ABS_X, elo->data[1]);
 		input_report_abs(dev, ABS_Y, elo->data[2]);
 		input_sync(dev);
 		elo->idx = 0;
 		break;
 	}
 }

 static irqreturn_t elo_interrupt(struct serio *serio,
 		unsigned char data, unsigned int flags)
 {
 	struct elo *elo = serio_get_drvdata(serio);

 	switch (elo->id) {
 	case 0:
 		elo_process_data_10(elo, data);
 		break;

 	case 1:
 	case 2:
 		elo_process_data_6(elo, data);
 		break;

 	case 3:
 		elo_process_data_3(elo, data);
 		break;
 	}

 	return IRQ_HANDLED;
 }

 static int elo_command_10(struct elo *elo, unsigned char *packet)
 {
 	int rc = -1;
 	int i;
 	unsigned char csum = 0xaa + ELO10_LEAD_BYTE;

 	mutex_lock(&elo->cmd_mutex);

 	serio_pause_rx(elo->serio);
 	elo->expected_packet = toupper(packet[0]);
 	init_completion(&elo->cmd_done);
 	serio_continue_rx(elo->serio);

 	if (serio_write(elo->serio, ELO10_LEAD_BYTE))
 		goto out;

 	for (i = 0; i < ELO10_PACKET_LEN; i++) {
 		csum += packet[i];
 		if (serio_write(elo->serio, packet[i]))
 			goto out;
 	}

 	if (serio_write(elo->serio, csum))
 		goto out;

 	wait_for_completion_timeout(&elo->cmd_done, HZ);

 	if (elo->expected_packet == ELO10_TOUCH_PACKET) {
 		/* We are back in reporting mode, the command was ACKed */
 		memcpy(packet, elo->response, ELO10_PACKET_LEN);
 		rc = 0;
 	}

  out:
 	mutex_unlock(&elo->cmd_mutex);
 	return rc;
 }

 static int elo_setup_10(struct elo *elo)
 {
 	static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
 	struct input_dev *dev = elo->dev;
 	unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };

 	if (elo_command_10(elo, packet))
 		return -1;

 	dev->id.version = (packet[5] << 8) | packet[4];

 	input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
 	input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
 	if (packet[3] & ELO10_PRESSURE)
 		input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);

 	dev_info(&elo->serio->dev,
 		 "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
 		 elo_types[(packet[1] -'0') & 0x03],
 		 packet[5], packet[4], packet[3], packet[7]);

 	return 0;
 }

 /*
  * elo_disconnect() is the opposite of elo_connect()
  */

 static void elo_disconnect(struct serio *serio)
 {
 	struct elo *elo = serio_get_drvdata(serio);

 	input_get_device(elo->dev);
 	input_unregister_device(elo->dev);
 	serio_close(serio);
 	serio_set_drvdata(serio, NULL);
 	input_put_device(elo->dev);
 	kfree(elo);
 }

 /*
  * elo_connect() is the routine that is called when someone adds a
  * new serio device that supports Gunze protocol and registers it as
  * an input device.
  */

 static int elo_connect(struct serio *serio, struct serio_driver *drv)
 {
 	struct elo *elo;
 	struct input_dev *input_dev;
 	int err;

 	elo = kzalloc(sizeof(*elo), GFP_KERNEL);
 	input_dev = input_allocate_device();
 	if (!elo || !input_dev) {
 		err = -ENOMEM;
 		goto fail1;
 	}

 	elo->serio = serio;
 	elo->id = serio->id.id;
 	elo->dev = input_dev;
 	elo->expected_packet = ELO10_TOUCH_PACKET;
 	mutex_init(&elo->cmd_mutex);
 	init_completion(&elo->cmd_done);
 	snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);

 	input_dev->name = "Elo Serial TouchScreen";
 	input_dev->phys = elo->phys;
 	input_dev->id.bustype = BUS_RS232;
 	input_dev->id.vendor = SERIO_ELO;
 	input_dev->id.product = elo->id;
 	input_dev->id.version = 0x0100;
 	input_dev->dev.parent = &serio->dev;

 	input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
 	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

 	serio_set_drvdata(serio, elo);
 	err = serio_open(serio, drv);
 	if (err)
 		goto fail2;

 	switch (elo->id) {

 	case 0: /* 10-byte protocol */
 		if (elo_setup_10(elo)) {
 			err = -EIO;
 			goto fail3;
 		}

 		break;

 	case 1: /* 6-byte protocol */
 		input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
 		fallthrough;

 	case 2: /* 4-byte protocol */
 		input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
 		input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
 		break;

 	case 3: /* 3-byte protocol */
 		input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
 		input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
 		break;
 	}

 	err = input_register_device(elo->dev);
 	if (err)
 		goto fail3;

 	return 0;

  fail3: serio_close(serio);
  fail2:	serio_set_drvdata(serio, NULL);
  fail1:	input_free_device(input_dev);
 	kfree(elo);
 	return err;
 }

 /*
  * The serio driver structure.
  */

 static const struct serio_device_id elo_serio_ids[] = {
 	{
 		.type	= SERIO_RS232,
 		.proto	= SERIO_ELO,
 		.id	= SERIO_ANY,
 		.extra	= SERIO_ANY,
 	},
 	{ 0 }
 };

 MODULE_DEVICE_TABLE(serio, elo_serio_ids);

 static struct serio_driver elo_drv = {
 	.driver		= {
 		.name	= "elo",
 	},
 	.description	= DRIVER_DESC,
 	.id_table	= elo_serio_ids,
 	.interrupt	= elo_interrupt,
 	.connect	= elo_connect,
 	.disconnect	= elo_disconnect,
 };

 module_serio_driver(elo_drv);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Elo serial touchscreen driver
	*
	* Copyright (c) 2004 Vojtech Pavlik
	*/


	/*
	* This driver can handle serial Elo touchscreens using either the Elo standard
	* 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo
	* legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol.
	*/

	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>
	#include <linux/input.h>
	#include <linux/serio.h>
	#include <linux/ctype.h>

	#define DRIVER_DESC "Elo serial touchscreen driver"

	MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
	MODULE_DESCRIPTION(DRIVER_DESC);
	MODULE_LICENSE("GPL");

	/*
	* Definitions & global arrays.
	*/

	#define ELO_MAX_LENGTH 10

	#define ELO10_PACKET_LEN 8
	#define ELO10_TOUCH 0x03
	#define ELO10_PRESSURE 0x80

	#define ELO10_LEAD_BYTE 'U'

	#define ELO10_ID_CMD 'i'

	#define ELO10_TOUCH_PACKET 'T'
	#define ELO10_ACK_PACKET 'A'
	#define ELI10_ID_PACKET 'I'

	/*
	* Per-touchscreen data.
	*/

	struct elo {
	struct input_dev *dev;
	struct serio *serio;
	struct mutex cmd_mutex;
	struct completion cmd_done;
	int id;
	int idx;
	unsigned char expected_packet;
	unsigned char csum;
	unsigned char data[ELO_MAX_LENGTH];
	unsigned char response[ELO10_PACKET_LEN];
	char phys[32];
	};

	static void elo_process_data_10(struct elo *elo, unsigned char data)
	{
	struct input_dev *dev = elo->dev;

	elo->data[elo->idx] = data;

	switch (elo->idx++) {
	case 0:
	elo->csum = 0xaa;
	if (data != ELO10_LEAD_BYTE) {
	dev_dbg(&elo->serio->dev,
	"unsynchronized data: 0x%02x\n", data);
	elo->idx = 0;
	}
	break;

	case 9:
	elo->idx = 0;
	if (data != elo->csum) {
	dev_dbg(&elo->serio->dev,
	"bad checksum: 0x%02x, expected 0x%02x\n",
	data, elo->csum);
	break;
	}
	if (elo->data[1] != elo->expected_packet) {
	if (elo->data[1] != ELO10_TOUCH_PACKET)
	dev_dbg(&elo->serio->dev,
	"unexpected packet: 0x%02x\n",
	elo->data[1]);
	break;
	}
	if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
	input_report_abs(dev, ABS_X, (elo->data[4] << 8) \| elo->data[3]);
	input_report_abs(dev, ABS_Y, (elo->data[6] << 8) \| elo->data[5]);
	if (elo->data[2] & ELO10_PRESSURE)
	input_report_abs(dev, ABS_PRESSURE,
	(elo->data[8] << 8) \| elo->data[7]);
	input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
	input_sync(dev);
	} else if (elo->data[1] == ELO10_ACK_PACKET) {
	if (elo->data[2] == '0')
	elo->expected_packet = ELO10_TOUCH_PACKET;
	complete(&elo->cmd_done);
	} else {
	memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
	elo->expected_packet = ELO10_ACK_PACKET;
	}
	break;
	}
	elo->csum += data;
	}

	static void elo_process_data_6(struct elo *elo, unsigned char data)
	{
	struct input_dev *dev = elo->dev;

	elo->data[elo->idx] = data;

	switch (elo->idx++) {

	case 0:
	if ((data & 0xc0) != 0xc0)
	elo->idx = 0;
	break;

	case 1:
	if ((data & 0xc0) != 0x80)
	elo->idx = 0;
	break;

	case 2:
	if ((data & 0xc0) != 0x40)
	elo->idx = 0;
	break;

	case 3:
	if (data & 0xc0) {
	elo->idx = 0;
	break;
	}

	input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) \| (elo->data[1] & 0x3f));
	input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) \| (elo->data[3] & 0x3f));

	if (elo->id == 2) {
	input_report_key(dev, BTN_TOUCH, 1);
	input_sync(dev);
	elo->idx = 0;
	}

	break;

	case 4:
	if (data) {
	input_sync(dev);
	elo->idx = 0;
	}
	break;

	case 5:
	if ((data & 0xf0) == 0) {
	input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
	input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
	}
	input_sync(dev);
	elo->idx = 0;
	break;
	}
	}

	static void elo_process_data_3(struct elo *elo, unsigned char data)
	{
	struct input_dev *dev = elo->dev;

	elo->data[elo->idx] = data;

	switch (elo->idx++) {

	case 0:
	if ((data & 0x7f) != 0x01)
	elo->idx = 0;
	break;
	case 2:
	input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
	input_report_abs(dev, ABS_X, elo->data[1]);
	input_report_abs(dev, ABS_Y, elo->data[2]);
	input_sync(dev);
	elo->idx = 0;
	break;
	}
	}

	static irqreturn_t elo_interrupt(struct serio *serio,
	unsigned char data, unsigned int flags)
	{
	struct elo *elo = serio_get_drvdata(serio);

	switch (elo->id) {
	case 0:
	elo_process_data_10(elo, data);
	break;

	case 1:
	case 2:
	elo_process_data_6(elo, data);
	break;

	case 3:
	elo_process_data_3(elo, data);
	break;
	}

	return IRQ_HANDLED;
	}

	static int elo_command_10(struct elo elo, unsigned char packet)
	{
	int rc = -1;
	int i;
	unsigned char csum = 0xaa + ELO10_LEAD_BYTE;

	mutex_lock(&elo->cmd_mutex);

	serio_pause_rx(elo->serio);
	elo->expected_packet = toupper(packet[0]);
	init_completion(&elo->cmd_done);
	serio_continue_rx(elo->serio);

	if (serio_write(elo->serio, ELO10_LEAD_BYTE))
	goto out;

	for (i = 0; i < ELO10_PACKET_LEN; i++) {
	csum += packet[i];
	if (serio_write(elo->serio, packet[i]))
	goto out;
	}

	if (serio_write(elo->serio, csum))
	goto out;

	wait_for_completion_timeout(&elo->cmd_done, HZ);

	if (elo->expected_packet == ELO10_TOUCH_PACKET) {
	/* We are back in reporting mode, the command was ACKed */
	memcpy(packet, elo->response, ELO10_PACKET_LEN);
	rc = 0;
	}

	out:
	mutex_unlock(&elo->cmd_mutex);
	return rc;
	}

	static int elo_setup_10(struct elo *elo)
	{
	static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
	struct input_dev *dev = elo->dev;
	unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };

	if (elo_command_10(elo, packet))
	return -1;

	dev->id.version = (packet[5] << 8) \| packet[4];

	input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
	input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
	if (packet[3] & ELO10_PRESSURE)
	input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);

	dev_info(&elo->serio->dev,
	"%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
	elo_types[(packet[1] -'0') & 0x03],
	packet[5], packet[4], packet[3], packet[7]);

	return 0;
	}

	/*
	* elo_disconnect() is the opposite of elo_connect()
	*/

	static void elo_disconnect(struct serio *serio)
	{
	struct elo *elo = serio_get_drvdata(serio);

	input_get_device(elo->dev);
	input_unregister_device(elo->dev);
	serio_close(serio);
	serio_set_drvdata(serio, NULL);
	input_put_device(elo->dev);
	kfree(elo);
	}

	/*
	* elo_connect() is the routine that is called when someone adds a
	* new serio device that supports Gunze protocol and registers it as
	* an input device.
	*/

	static int elo_connect(struct serio serio, struct serio_driver drv)
	{
	struct elo *elo;
	struct input_dev *input_dev;
	int err;

	elo = kzalloc(sizeof(*elo), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!elo \|\| !input_dev) {
	err = -ENOMEM;
	goto fail1;
	}

	elo->serio = serio;
	elo->id = serio->id.id;
	elo->dev = input_dev;
	elo->expected_packet = ELO10_TOUCH_PACKET;
	mutex_init(&elo->cmd_mutex);
	init_completion(&elo->cmd_done);
	snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);

	input_dev->name = "Elo Serial TouchScreen";
	input_dev->phys = elo->phys;
	input_dev->id.bustype = BUS_RS232;
	input_dev->id.vendor = SERIO_ELO;
	input_dev->id.product = elo->id;
	input_dev->id.version = 0x0100;
	input_dev->dev.parent = &serio->dev;

	input_dev->evbit[0] = BIT_MASK(EV_KEY) \| BIT_MASK(EV_ABS);
	input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

	serio_set_drvdata(serio, elo);
	err = serio_open(serio, drv);
	if (err)
	goto fail2;

	switch (elo->id) {

	case 0: /* 10-byte protocol */
	if (elo_setup_10(elo)) {
	err = -EIO;
	goto fail3;
	}

	break;

	case 1: /* 6-byte protocol */
	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
	fallthrough;

	case 2: /* 4-byte protocol */
	input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
	break;

	case 3: /* 3-byte protocol */
	input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
	input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
	break;
	}

	err = input_register_device(elo->dev);
	if (err)
	goto fail3;

	return 0;

	fail3: serio_close(serio);
	fail2: serio_set_drvdata(serio, NULL);
	fail1: input_free_device(input_dev);
	kfree(elo);
	return err;
	}

	/*
	* The serio driver structure.
	*/

	static const struct serio_device_id elo_serio_ids[] = {
	{
	.type = SERIO_RS232,
	.proto = SERIO_ELO,
	.id = SERIO_ANY,
	.extra = SERIO_ANY,
	},
	{ 0 }
	};

	MODULE_DEVICE_TABLE(serio, elo_serio_ids);

	static struct serio_driver elo_drv = {
	.driver = {
	.name = "elo",
	},
	.description = DRIVER_DESC,
	.id_table = elo_serio_ids,
	.interrupt = elo_interrupt,
	.connect = elo_connect,
	.disconnect = elo_disconnect,
	};

	module_serio_driver(elo_drv);