// SPDX-License-Identifier: GPL-2.0-or-later/* *  Copyright (c) 2000-2001 Vojtech Pavlik */ /* * Gunze AHL-51S touchscreen driver for Linux */ #include <linux/errno.h>#include <linux/kernel.h>#include <linux/module.h>#include <linux/slab.h>#include <linux/input.h>#include <linux/serio.h> #define DRIVER_DESC	"Gunze AHL-51S touchscreen driver" MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");MODULE_DESCRIPTION(DRIVER_DESC);MODULE_LICENSE("GPL"); /* * Definitions & global arrays. */ #define	GUNZE_MAX_LENGTH	10 /* * Per-touchscreen data. */ struct gunze {	struct input_dev *dev;	struct serio *serio;	int idx;	unsigned char data[GUNZE_MAX_LENGTH];	char phys[32];}; static void gunze_process_packet(struct gunze *gunze){	struct input_dev *dev = gunze->dev; 	if (gunze->idx != GUNZE_MAX_LENGTH || gunze->data[5] != ',' ||		(gunze->data[0] != 'T' && gunze->data[0] != 'R')) {		printk(KERN_WARNING "gunze.c: bad packet: >%.*s<\n", GUNZE_MAX_LENGTH, gunze->data);		return;	} 	input_report_abs(dev, ABS_X, simple_strtoul(gunze->data + 1, NULL, 10));	input_report_abs(dev, ABS_Y, 1024 - simple_strtoul(gunze->data + 6, NULL, 10));	input_report_key(dev, BTN_TOUCH, gunze->data[0] == 'T');	input_sync(dev);} static irqreturn_t gunze_interrupt(struct serio *serio,		unsigned char data, unsigned int flags){	struct gunze *gunze = serio_get_drvdata(serio); 	if (data == '\r') {		gunze_process_packet(gunze);		gunze->idx = 0;	} else {		if (gunze->idx < GUNZE_MAX_LENGTH)			gunze->data[gunze->idx++] = data;	}	return IRQ_HANDLED;} /* * gunze_disconnect() is the opposite of gunze_connect() */ static void gunze_disconnect(struct serio *serio){	struct gunze *gunze = serio_get_drvdata(serio); 	input_get_device(gunze->dev);	input_unregister_device(gunze->dev);	serio_close(serio);	serio_set_drvdata(serio, NULL);	input_put_device(gunze->dev);	kfree(gunze);} /* * gunze_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 gunze_connect(struct serio *serio, struct serio_driver *drv){	struct gunze *gunze;	struct input_dev *input_dev;	int err; 	gunze = kzalloc_obj(*gunze);	input_dev = input_allocate_device();	if (!gunze || !input_dev) {		err = -ENOMEM;		goto fail1;	} 	gunze->serio = serio;	gunze->dev = input_dev;	scnprintf(gunze->phys, sizeof(serio->phys), "%s/input0", serio->phys); 	input_dev->name = "Gunze AHL-51S TouchScreen";	input_dev->phys = gunze->phys;	input_dev->id.bustype = BUS_RS232;	input_dev->id.vendor = SERIO_GUNZE;	input_dev->id.product = 0x0051;	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);	input_set_abs_params(input_dev, ABS_X, 24, 1000, 0, 0);	input_set_abs_params(input_dev, ABS_Y, 24, 1000, 0, 0); 	serio_set_drvdata(serio, gunze); 	err = serio_open(serio, drv);	if (err)		goto fail2; 	err = input_register_device(gunze->dev);	if (err)		goto fail3; 	return 0;  fail3:	serio_close(serio); fail2:	serio_set_drvdata(serio, NULL); fail1:	input_free_device(input_dev);	kfree(gunze);	return err;} /* * The serio driver structure. */ static const struct serio_device_id gunze_serio_ids[] = {	{		.type	= SERIO_RS232,		.proto	= SERIO_GUNZE,		.id	= SERIO_ANY,		.extra	= SERIO_ANY,	},	{ 0 }}; MODULE_DEVICE_TABLE(serio, gunze_serio_ids); static struct serio_driver gunze_drv = {	.driver		= {		.name	= "gunze",	},	.description	= DRIVER_DESC,	.id_table	= gunze_serio_ids,	.interrupt	= gunze_interrupt,	.connect	= gunze_connect,	.disconnect	= gunze_disconnect,}; module_serio_driver(gunze_drv);