Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block
[pandora-kernel.git] / drivers / input / touchscreen / touchit213.c
1 /*
2  * Sahara TouchIT-213 serial touchscreen driver
3  *
4  * Copyright (c) 2007-2008 Claudio Nieder <private@claudio.ch>
5  *
6  * Based on Touchright driver (drivers/input/touchscreen/touchright.c)
7  * Copyright (c) 2006 Rick Koch <n1gp@hotmail.com>
8  * Copyright (c) 2004 Vojtech Pavlik
9  * and Dan Streetman <ddstreet@ieee.org>
10  */
11
12 /*
13  * This program is free software; you can redistribute it and/or modify it
14  * under the terms of the GNU General Public License version 2 as published
15  * by the Free Software Foundation.
16  */
17
18 #include <linux/errno.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/input.h>
23 #include <linux/serio.h>
24 #include <linux/init.h>
25
26 #define DRIVER_DESC     "Sahara TouchIT-213 serial touchscreen driver"
27
28 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
29 MODULE_DESCRIPTION(DRIVER_DESC);
30 MODULE_LICENSE("GPL");
31
32 /*
33  * Definitions & global arrays.
34  */
35
36 /*
37  * Data is received through COM1 at 9600bit/s,8bit,no parity in packets
38  * of 5 byte each.
39  *
40  *   +--------+   +--------+   +--------+   +--------+   +--------+
41  *   |1000000p|   |0xxxxxxx|   |0xxxxxxx|   |0yyyyyyy|   |0yyyyyyy|
42  *   +--------+   +--------+   +--------+   +--------+   +--------+
43  *                    MSB          LSB          MSB          LSB
44  *
45  * The value of p is 1 as long as the screen is touched and 0 when
46  * reporting the location where touching stopped, e.g. where the pen was
47  * lifted from the screen.
48  *
49  * When holding the screen in landscape mode as the BIOS text output is
50  * presented, x is the horizontal axis with values growing from left to
51  * right and y is the vertical axis with values growing from top to
52  * bottom.
53  *
54  * When holding the screen in portrait mode with the Sahara logo in its
55  * correct position, x ist the vertical axis with values growing from
56  * top to bottom and y is the horizontal axis with values growing from
57  * right to left.
58  */
59
60 #define T213_FORMAT_TOUCH_BIT   0x01
61 #define T213_FORMAT_STATUS_BYTE 0x80
62 #define T213_FORMAT_STATUS_MASK ~T213_FORMAT_TOUCH_BIT
63
64 /*
65  * On my Sahara Touch-IT 213 I have observed x values from 0 to 0x7f0
66  * and y values from 0x1d to 0x7e9, so the actual measurement is
67  * probably done with an 11 bit precision.
68  */
69 #define T213_MIN_XC 0
70 #define T213_MAX_XC 0x07ff
71 #define T213_MIN_YC 0
72 #define T213_MAX_YC 0x07ff
73
74 /*
75  * Per-touchscreen data.
76  */
77
78 struct touchit213 {
79         struct input_dev *dev;
80         struct serio *serio;
81         int idx;
82         unsigned char csum;
83         unsigned char data[5];
84         char phys[32];
85 };
86
87 static irqreturn_t touchit213_interrupt(struct serio *serio,
88                 unsigned char data, unsigned int flags)
89 {
90         struct touchit213 *touchit213 = serio_get_drvdata(serio);
91         struct input_dev *dev = touchit213->dev;
92
93         touchit213->data[touchit213->idx] = data;
94
95         switch (touchit213->idx++) {
96         case 0:
97                 if ((touchit213->data[0] & T213_FORMAT_STATUS_MASK) !=
98                                 T213_FORMAT_STATUS_BYTE) {
99                         pr_debug("unsynchronized data: 0x%02x\n", data);
100                         touchit213->idx = 0;
101                 }
102                 break;
103
104         case 4:
105                 touchit213->idx = 0;
106                 input_report_abs(dev, ABS_X,
107                         (touchit213->data[1] << 7) | touchit213->data[2]);
108                 input_report_abs(dev, ABS_Y,
109                         (touchit213->data[3] << 7) | touchit213->data[4]);
110                 input_report_key(dev, BTN_TOUCH,
111                         touchit213->data[0] & T213_FORMAT_TOUCH_BIT);
112                 input_sync(dev);
113                 break;
114         }
115
116         return IRQ_HANDLED;
117 }
118
119 /*
120  * touchit213_disconnect() is the opposite of touchit213_connect()
121  */
122
123 static void touchit213_disconnect(struct serio *serio)
124 {
125         struct touchit213 *touchit213 = serio_get_drvdata(serio);
126
127         input_get_device(touchit213->dev);
128         input_unregister_device(touchit213->dev);
129         serio_close(serio);
130         serio_set_drvdata(serio, NULL);
131         input_put_device(touchit213->dev);
132         kfree(touchit213);
133 }
134
135 /*
136  * touchit213_connect() is the routine that is called when someone adds a
137  * new serio device that supports the Touchright protocol and registers it as
138  * an input device.
139  */
140
141 static int touchit213_connect(struct serio *serio, struct serio_driver *drv)
142 {
143         struct touchit213 *touchit213;
144         struct input_dev *input_dev;
145         int err;
146
147         touchit213 = kzalloc(sizeof(struct touchit213), GFP_KERNEL);
148         input_dev = input_allocate_device();
149         if (!touchit213 || !input_dev) {
150                 err = -ENOMEM;
151                 goto fail1;
152         }
153
154         touchit213->serio = serio;
155         touchit213->dev = input_dev;
156         snprintf(touchit213->phys, sizeof(touchit213->phys),
157                  "%s/input0", serio->phys);
158
159         input_dev->name = "Sahara Touch-iT213 Serial TouchScreen";
160         input_dev->phys = touchit213->phys;
161         input_dev->id.bustype = BUS_RS232;
162         input_dev->id.vendor = SERIO_TOUCHIT213;
163         input_dev->id.product = 0;
164         input_dev->id.version = 0x0100;
165         input_dev->dev.parent = &serio->dev;
166         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
167         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
168         input_set_abs_params(touchit213->dev, ABS_X,
169                              T213_MIN_XC, T213_MAX_XC, 0, 0);
170         input_set_abs_params(touchit213->dev, ABS_Y,
171                              T213_MIN_YC, T213_MAX_YC, 0, 0);
172
173         serio_set_drvdata(serio, touchit213);
174
175         err = serio_open(serio, drv);
176         if (err)
177                 goto fail2;
178
179         err = input_register_device(touchit213->dev);
180         if (err)
181                 goto fail3;
182
183         return 0;
184
185  fail3: serio_close(serio);
186  fail2: serio_set_drvdata(serio, NULL);
187  fail1: input_free_device(input_dev);
188         kfree(touchit213);
189         return err;
190 }
191
192 /*
193  * The serio driver structure.
194  */
195
196 static struct serio_device_id touchit213_serio_ids[] = {
197         {
198                 .type   = SERIO_RS232,
199                 .proto  = SERIO_TOUCHIT213,
200                 .id     = SERIO_ANY,
201                 .extra  = SERIO_ANY,
202         },
203         { 0 }
204 };
205
206 MODULE_DEVICE_TABLE(serio, touchit213_serio_ids);
207
208 static struct serio_driver touchit213_drv = {
209         .driver         = {
210                 .name   = "touchit213",
211         },
212         .description    = DRIVER_DESC,
213         .id_table       = touchit213_serio_ids,
214         .interrupt      = touchit213_interrupt,
215         .connect        = touchit213_connect,
216         .disconnect     = touchit213_disconnect,
217 };
218
219 /*
220  * The functions for inserting/removing us as a module.
221  */
222
223 static int __init touchit213_init(void)
224 {
225         return serio_register_driver(&touchit213_drv);
226 }
227
228 static void __exit touchit213_exit(void)
229 {
230         serio_unregister_driver(&touchit213_drv);
231 }
232
233 module_init(touchit213_init);
234 module_exit(touchit213_exit);