tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Wacom W8001 penabled serial touchscreen driver
3 *
4 * Copyright (c) 2008 Jaya Kumar
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive for
8 * more details.
9 *
10 * Layout based on Elo serial touchscreen driver by Vojtech Pavlik
11 */
12
13#include <linux/errno.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/input.h>
18#include <linux/serio.h>
19#include <linux/init.h>
20#include <linux/ctype.h>
21
22#define DRIVER_DESC "Wacom W8001 serial touchscreen driver"
23
24MODULE_AUTHOR("Jaya Kumar <jayakumar.lkml@gmail.com>");
25MODULE_DESCRIPTION(DRIVER_DESC);
26MODULE_LICENSE("GPL");
27
28/*
29 * Definitions & global arrays.
30 */
31
32#define W8001_MAX_LENGTH 11
33#define W8001_PACKET_LEN 11
34#define W8001_LEAD_MASK 0x80
35#define W8001_LEAD_BYTE 0x80
36#define W8001_TAB_MASK 0x40
37#define W8001_TAB_BYTE 0x40
38
39#define W8001_QUERY_PACKET 0x20
40
41struct w8001_coord {
42 u8 rdy;
43 u8 tsw;
44 u8 f1;
45 u8 f2;
46 u16 x;
47 u16 y;
48 u16 pen_pressure;
49 u8 tilt_x;
50 u8 tilt_y;
51};
52
53/*
54 * Per-touchscreen data.
55 */
56
57struct w8001 {
58 struct input_dev *dev;
59 struct serio *serio;
60 struct mutex cmd_mutex;
61 struct completion cmd_done;
62 int id;
63 int idx;
64 unsigned char expected_packet;
65 unsigned char data[W8001_MAX_LENGTH];
66 unsigned char response[W8001_PACKET_LEN];
67 char phys[32];
68};
69
70static int parse_data(u8 *data, struct w8001_coord *coord)
71{
72 coord->rdy = data[0] & 0x20;
73 coord->tsw = data[0] & 0x01;
74 coord->f1 = data[0] & 0x02;
75 coord->f2 = data[0] & 0x04;
76
77 coord->x = (data[1] & 0x7F) << 9;
78 coord->x |= (data[2] & 0x7F) << 2;
79 coord->x |= (data[6] & 0x60) >> 5;
80
81 coord->y = (data[3] & 0x7F) << 9;
82 coord->y |= (data[4] & 0x7F) << 2;
83 coord->y |= (data[6] & 0x18) >> 3;
84
85 coord->pen_pressure = data[5] & 0x7F;
86 coord->pen_pressure |= (data[6] & 0x07) << 7 ;
87
88 coord->tilt_x = data[7] & 0x7F;
89 coord->tilt_y = data[8] & 0x7F;
90
91 return 0;
92}
93
94static void w8001_process_data(struct w8001 *w8001, unsigned char data)
95{
96 struct input_dev *dev = w8001->dev;
97 u8 tmp;
98 struct w8001_coord coord;
99
100 w8001->data[w8001->idx] = data;
101 switch (w8001->idx++) {
102 case 0:
103 if ((data & W8001_LEAD_MASK) != W8001_LEAD_BYTE) {
104 pr_debug("w8001: unsynchronized data: 0x%02x\n", data);
105 w8001->idx = 0;
106 }
107 break;
108 case 8:
109 tmp = w8001->data[0] & W8001_TAB_MASK;
110 if (unlikely(tmp == W8001_TAB_BYTE))
111 break;
112 w8001->idx = 0;
113 memset(&coord, 0, sizeof(coord));
114 parse_data(w8001->data, &coord);
115 input_report_abs(dev, ABS_X, coord.x);
116 input_report_abs(dev, ABS_Y, coord.y);
117 input_report_abs(dev, ABS_PRESSURE, coord.pen_pressure);
118 input_report_key(dev, BTN_TOUCH, coord.tsw);
119 input_sync(dev);
120 break;
121 case 10:
122 w8001->idx = 0;
123 memcpy(w8001->response, &w8001->data, W8001_PACKET_LEN);
124 w8001->expected_packet = W8001_QUERY_PACKET;
125 complete(&w8001->cmd_done);
126 break;
127 }
128}
129
130
131static irqreturn_t w8001_interrupt(struct serio *serio,
132 unsigned char data, unsigned int flags)
133{
134 struct w8001 *w8001 = serio_get_drvdata(serio);
135
136 w8001_process_data(w8001, data);
137
138 return IRQ_HANDLED;
139}
140
141static int w8001_async_command(struct w8001 *w8001, unsigned char *packet,
142 int len)
143{
144 int rc = -1;
145 int i;
146
147 mutex_lock(&w8001->cmd_mutex);
148
149 for (i = 0; i < len; i++) {
150 if (serio_write(w8001->serio, packet[i]))
151 goto out;
152 }
153 rc = 0;
154
155out:
156 mutex_unlock(&w8001->cmd_mutex);
157 return rc;
158}
159
160static int w8001_command(struct w8001 *w8001, unsigned char *packet, int len)
161{
162 int rc = -1;
163 int i;
164
165 mutex_lock(&w8001->cmd_mutex);
166
167 serio_pause_rx(w8001->serio);
168 init_completion(&w8001->cmd_done);
169 serio_continue_rx(w8001->serio);
170
171 for (i = 0; i < len; i++) {
172 if (serio_write(w8001->serio, packet[i]))
173 goto out;
174 }
175
176 wait_for_completion_timeout(&w8001->cmd_done, HZ);
177
178 if (w8001->expected_packet == W8001_QUERY_PACKET) {
179 /* We are back in reporting mode, the query was ACKed */
180 memcpy(packet, w8001->response, W8001_PACKET_LEN);
181 rc = 0;
182 }
183
184out:
185 mutex_unlock(&w8001->cmd_mutex);
186 return rc;
187}
188
189static int w8001_setup(struct w8001 *w8001)
190{
191 struct w8001_coord coord;
192 struct input_dev *dev = w8001->dev;
193 unsigned char start[1] = { '1' };
194 unsigned char query[11] = { '*' };
195
196 if (w8001_command(w8001, query, 1))
197 return -1;
198
199 memset(&coord, 0, sizeof(coord));
200 parse_data(query, &coord);
201
202 input_set_abs_params(dev, ABS_X, 0, coord.x, 0, 0);
203 input_set_abs_params(dev, ABS_Y, 0, coord.y, 0, 0);
204 input_set_abs_params(dev, ABS_PRESSURE, 0, coord.pen_pressure, 0, 0);
205 input_set_abs_params(dev, ABS_TILT_X, 0, coord.tilt_x, 0, 0);
206 input_set_abs_params(dev, ABS_TILT_Y, 0, coord.tilt_y, 0, 0);
207
208 if (w8001_async_command(w8001, start, 1))
209 return -1;
210
211 return 0;
212}
213
214/*
215 * w8001_disconnect() is the opposite of w8001_connect()
216 */
217
218static void w8001_disconnect(struct serio *serio)
219{
220 struct w8001 *w8001 = serio_get_drvdata(serio);
221
222 input_get_device(w8001->dev);
223 input_unregister_device(w8001->dev);
224 serio_close(serio);
225 serio_set_drvdata(serio, NULL);
226 input_put_device(w8001->dev);
227 kfree(w8001);
228}
229
230/*
231 * w8001_connect() is the routine that is called when someone adds a
232 * new serio device that supports the w8001 protocol and registers it as
233 * an input device.
234 */
235
236static int w8001_connect(struct serio *serio, struct serio_driver *drv)
237{
238 struct w8001 *w8001;
239 struct input_dev *input_dev;
240 int err;
241
242 w8001 = kzalloc(sizeof(struct w8001), GFP_KERNEL);
243 input_dev = input_allocate_device();
244 if (!w8001 || !input_dev) {
245 err = -ENOMEM;
246 goto fail1;
247 }
248
249 w8001->serio = serio;
250 w8001->id = serio->id.id;
251 w8001->dev = input_dev;
252 mutex_init(&w8001->cmd_mutex);
253 init_completion(&w8001->cmd_done);
254 snprintf(w8001->phys, sizeof(w8001->phys), "%s/input0", serio->phys);
255
256 input_dev->name = "Wacom W8001 Penabled Serial TouchScreen";
257 input_dev->phys = w8001->phys;
258 input_dev->id.bustype = BUS_RS232;
259 input_dev->id.vendor = SERIO_W8001;
260 input_dev->id.product = w8001->id;
261 input_dev->id.version = 0x0100;
262 input_dev->dev.parent = &serio->dev;
263
264 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
265 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
266
267 serio_set_drvdata(serio, w8001);
268 err = serio_open(serio, drv);
269 if (err)
270 goto fail2;
271
272 if (w8001_setup(w8001))
273 goto fail3;
274
275 err = input_register_device(w8001->dev);
276 if (err)
277 goto fail3;
278
279 return 0;
280
281fail3:
282 serio_close(serio);
283fail2:
284 serio_set_drvdata(serio, NULL);
285fail1:
286 input_free_device(input_dev);
287 kfree(w8001);
288 return err;
289}
290
291static struct serio_device_id w8001_serio_ids[] = {
292 {
293 .type = SERIO_RS232,
294 .proto = SERIO_W8001,
295 .id = SERIO_ANY,
296 .extra = SERIO_ANY,
297 },
298 { 0 }
299};
300
301MODULE_DEVICE_TABLE(serio, w8001_serio_ids);
302
303static struct serio_driver w8001_drv = {
304 .driver = {
305 .name = "w8001",
306 },
307 .description = DRIVER_DESC,
308 .id_table = w8001_serio_ids,
309 .interrupt = w8001_interrupt,
310 .connect = w8001_connect,
311 .disconnect = w8001_disconnect,
312};
313
314static int __init w8001_init(void)
315{
316 return serio_register_driver(&w8001_drv);
317}
318
319static void __exit w8001_exit(void)
320{
321 serio_unregister_driver(&w8001_drv);
322}
323
324module_init(w8001_init);
325module_exit(w8001_exit);