// 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(struct 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);