1 // SPDX-License-Identifier: GPL-2.0-only
3 * Touchwindow serial touchscreen driver
5 * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
7 * Based on MicroTouch driver (drivers/input/touchscreen/mtouch.c)
8 * Copyright (c) 2004 Vojtech Pavlik
9 * and Dan Streetman <ddstreet@ieee.org>
14 * 2005/02/19 Rick Koch:
15 * The Touchwindow I used is made by Edmark Corp. and
16 * constantly outputs a stream of 0's unless it is touched.
17 * It then outputs 3 bytes: X, Y, and a copy of Y.
20 #include <linux/errno.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <linux/input.h>
25 #include <linux/serio.h>
27 #define DRIVER_DESC "Touchwindow serial touchscreen driver"
29 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
30 MODULE_DESCRIPTION(DRIVER_DESC
);
31 MODULE_LICENSE("GPL");
34 * Definitions & global arrays.
40 #define TW_MAX_XC 0xff
42 #define TW_MAX_YC 0xff
45 * Per-touchscreen data.
49 struct input_dev
*dev
;
53 unsigned char data
[TW_LENGTH
];
57 static irqreturn_t
tw_interrupt(struct serio
*serio
,
58 unsigned char data
, unsigned int flags
)
60 struct tw
*tw
= serio_get_drvdata(serio
);
61 struct input_dev
*dev
= tw
->dev
;
63 if (data
) { /* touch */
65 tw
->data
[tw
->idx
++] = data
;
66 /* verify length and that the two Y's are the same */
67 if (tw
->idx
== TW_LENGTH
&& tw
->data
[1] == tw
->data
[2]) {
68 input_report_abs(dev
, ABS_X
, tw
->data
[0]);
69 input_report_abs(dev
, ABS_Y
, tw
->data
[1]);
70 input_report_key(dev
, BTN_TOUCH
, 1);
74 } else if (tw
->touched
) { /* untouch */
75 input_report_key(dev
, BTN_TOUCH
, 0);
85 * tw_disconnect() is the opposite of tw_connect()
88 static void tw_disconnect(struct serio
*serio
)
90 struct tw
*tw
= serio_get_drvdata(serio
);
92 input_get_device(tw
->dev
);
93 input_unregister_device(tw
->dev
);
95 serio_set_drvdata(serio
, NULL
);
96 input_put_device(tw
->dev
);
101 * tw_connect() is the routine that is called when someone adds a
102 * new serio device that supports the Touchwin protocol and registers it as
106 static int tw_connect(struct serio
*serio
, struct serio_driver
*drv
)
109 struct input_dev
*input_dev
;
112 tw
= kzalloc(sizeof(struct tw
), GFP_KERNEL
);
113 input_dev
= input_allocate_device();
114 if (!tw
|| !input_dev
) {
121 snprintf(tw
->phys
, sizeof(tw
->phys
), "%s/input0", serio
->phys
);
123 input_dev
->name
= "Touchwindow Serial TouchScreen";
124 input_dev
->phys
= tw
->phys
;
125 input_dev
->id
.bustype
= BUS_RS232
;
126 input_dev
->id
.vendor
= SERIO_TOUCHWIN
;
127 input_dev
->id
.product
= 0;
128 input_dev
->id
.version
= 0x0100;
129 input_dev
->dev
.parent
= &serio
->dev
;
130 input_dev
->evbit
[0] = BIT_MASK(EV_KEY
) | BIT_MASK(EV_ABS
);
131 input_dev
->keybit
[BIT_WORD(BTN_TOUCH
)] = BIT_MASK(BTN_TOUCH
);
132 input_set_abs_params(tw
->dev
, ABS_X
, TW_MIN_XC
, TW_MAX_XC
, 0, 0);
133 input_set_abs_params(tw
->dev
, ABS_Y
, TW_MIN_YC
, TW_MAX_YC
, 0, 0);
135 serio_set_drvdata(serio
, tw
);
137 err
= serio_open(serio
, drv
);
141 err
= input_register_device(tw
->dev
);
147 fail3
: serio_close(serio
);
148 fail2
: serio_set_drvdata(serio
, NULL
);
149 fail1
: input_free_device(input_dev
);
155 * The serio driver structure.
158 static const struct serio_device_id tw_serio_ids
[] = {
161 .proto
= SERIO_TOUCHWIN
,
168 MODULE_DEVICE_TABLE(serio
, tw_serio_ids
);
170 static struct serio_driver tw_drv
= {
174 .description
= DRIVER_DESC
,
175 .id_table
= tw_serio_ids
,
176 .interrupt
= tw_interrupt
,
177 .connect
= tw_connect
,
178 .disconnect
= tw_disconnect
,
181 module_serio_driver(tw_drv
);