1 /*
2  * Penmount serial touchscreen driver
3  *
4  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
5  *
6  * Based on ELO driver (drivers/input/touchscreen/elo.c)
7  * Copyright (c) 2004 Vojtech Pavlik
8  */
9 
10 /*
11  * This program is free software; you can redistribute it and/or modify it
12  * under the terms of the GNU General Public License version 2 as published
13  * by the Free Software Foundation.
14  */
15 
16 #include <linux/errno.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/input.h>
21 #include <linux/serio.h>
22 #include <linux/init.h>
23 
24 #define DRIVER_DESC	"Penmount serial touchscreen driver"
25 
26 MODULE_AUTHOR("Rick Koch <n1gp@hotmail.com>");
27 MODULE_DESCRIPTION(DRIVER_DESC);
28 MODULE_LICENSE("GPL");
29 
30 /*
31  * Definitions & global arrays.
32  */
33 
34 #define	PM_MAX_LENGTH	5
35 
36 /*
37  * Per-touchscreen data.
38  */
39 
40 struct pm {
41 	struct input_dev *dev;
42 	struct serio *serio;
43 	int idx;
44 	unsigned char data[PM_MAX_LENGTH];
45 	char phys[32];
46 };
47 
48 static irqreturn_t pm_interrupt(struct serio *serio,
49 		unsigned char data, unsigned int flags)
50 {
51 	struct pm *pm = serio_get_drvdata(serio);
52 	struct input_dev *dev = pm->dev;
53 
54 	pm->data[pm->idx] = data;
55 
56 	if (pm->data[0] & 0x80) {
57 		if (PM_MAX_LENGTH == ++pm->idx) {
58 			input_report_abs(dev, ABS_X, pm->data[2] * 128 + pm->data[1]);
59 			input_report_abs(dev, ABS_Y, pm->data[4] * 128 + pm->data[3]);
60 			input_report_key(dev, BTN_TOUCH, !!(pm->data[0] & 0x40));
61 			input_sync(dev);
62 			pm->idx = 0;
63 		}
64 	}
65 
66 	return IRQ_HANDLED;
67 }
68 
69 /*
70  * pm_disconnect() is the opposite of pm_connect()
71  */
72 
73 static void pm_disconnect(struct serio *serio)
74 {
75 	struct pm *pm = serio_get_drvdata(serio);
76 
77 	input_get_device(pm->dev);
78 	input_unregister_device(pm->dev);
79 	serio_close(serio);
80 	serio_set_drvdata(serio, NULL);
81 	input_put_device(pm->dev);
82 	kfree(pm);
83 }
84 
85 /*
86  * pm_connect() is the routine that is called when someone adds a
87  * new serio device that supports Gunze protocol and registers it as
88  * an input device.
89  */
90 
91 static int pm_connect(struct serio *serio, struct serio_driver *drv)
92 {
93 	struct pm *pm;
94 	struct input_dev *input_dev;
95 	int err;
96 
97 	pm = kzalloc(sizeof(struct pm), GFP_KERNEL);
98 	input_dev = input_allocate_device();
99 	if (!pm || !input_dev) {
100 		err = -ENOMEM;
101 		goto fail1;
102 	}
103 
104 	pm->serio = serio;
105 	pm->dev = input_dev;
106 	snprintf(pm->phys, sizeof(pm->phys), "%s/input0", serio->phys);
107 
108 	input_dev->name = "Penmount Serial TouchScreen";
109 	input_dev->phys = pm->phys;
110 	input_dev->id.bustype = BUS_RS232;
111 	input_dev->id.vendor = SERIO_PENMOUNT;
112 	input_dev->id.product = 0;
113 	input_dev->id.version = 0x0100;
114 	input_dev->dev.parent = &serio->dev;
115 
116         input_dev->evbit[0] = BIT(EV_KEY) | BIT(EV_ABS);
117         input_dev->keybit[LONG(BTN_TOUCH)] = BIT(BTN_TOUCH);
118         input_set_abs_params(pm->dev, ABS_X, 0, 0x3ff, 0, 0);
119         input_set_abs_params(pm->dev, ABS_Y, 0, 0x3ff, 0, 0);
120 
121 	serio_set_drvdata(serio, pm);
122 
123 	err = serio_open(serio, drv);
124 	if (err)
125 		goto fail2;
126 
127 	err = input_register_device(pm->dev);
128 	if (err)
129 		goto fail3;
130 
131 	return 0;
132 
133  fail3:	serio_close(serio);
134  fail2:	serio_set_drvdata(serio, NULL);
135  fail1:	input_free_device(input_dev);
136 	kfree(pm);
137 	return err;
138 }
139 
140 /*
141  * The serio driver structure.
142  */
143 
144 static struct serio_device_id pm_serio_ids[] = {
145 	{
146 		.type	= SERIO_RS232,
147 		.proto	= SERIO_PENMOUNT,
148 		.id	= SERIO_ANY,
149 		.extra	= SERIO_ANY,
150 	},
151 	{ 0 }
152 };
153 
154 MODULE_DEVICE_TABLE(serio, pm_serio_ids);
155 
156 static struct serio_driver pm_drv = {
157 	.driver		= {
158 		.name	= "penmountlpc",
159 	},
160 	.description	= DRIVER_DESC,
161 	.id_table	= pm_serio_ids,
162 	.interrupt	= pm_interrupt,
163 	.connect	= pm_connect,
164 	.disconnect	= pm_disconnect,
165 };
166 
167 /*
168  * The functions for inserting/removing us as a module.
169  */
170 
171 static int __init pm_init(void)
172 {
173 	return serio_register_driver(&pm_drv);
174 }
175 
176 static void __exit pm_exit(void)
177 {
178 	serio_unregister_driver(&pm_drv);
179 }
180 
181 module_init(pm_init);
182 module_exit(pm_exit);
183