blob: 9029bd3f34e5ee9b5c12e3ef41c04c09001a45b1 [file] [log] [blame]
Daniel Mack10494dc2009-05-18 16:10:39 -07001/*
2 * Touch Screen driver for EETI's I2C connected touch screen panels
3 * Copyright (c) 2009 Daniel Mack <daniel@caiaq.de>
4 *
5 * See EETI's software guide for the protocol specification:
6 * http://home.eeti.com.tw/web20/eg/guide.htm
7 *
8 * Based on migor_ts.c
9 * Copyright (c) 2008 Magnus Damm
10 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
11 *
12 * This file is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public
14 * License as published by the Free Software Foundation; either
15 * version 2 of the License, or (at your option) any later version.
16 *
17 * This file is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public
23 * License along with this library; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 */
26
27#include <linux/module.h>
28#include <linux/moduleparam.h>
29#include <linux/kernel.h>
30#include <linux/input.h>
31#include <linux/interrupt.h>
32#include <linux/i2c.h>
33#include <linux/timer.h>
34#include <linux/gpio.h>
Daniel Mack25a70e32009-08-12 00:50:09 -070035#include <linux/input/eeti_ts.h>
Daniel Mack10494dc2009-05-18 16:10:39 -070036
37static int flip_x;
38module_param(flip_x, bool, 0644);
39MODULE_PARM_DESC(flip_x, "flip x coordinate");
40
41static int flip_y;
42module_param(flip_y, bool, 0644);
43MODULE_PARM_DESC(flip_y, "flip y coordinate");
44
45struct eeti_ts_priv {
46 struct i2c_client *client;
47 struct input_dev *input;
48 struct work_struct work;
49 struct mutex mutex;
Daniel Mack25a70e32009-08-12 00:50:09 -070050 int irq, irq_active_high;
Daniel Mack10494dc2009-05-18 16:10:39 -070051};
52
53#define EETI_TS_BITDEPTH (11)
54#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
55
56#define REPORT_BIT_PRESSED (1 << 0)
57#define REPORT_BIT_AD0 (1 << 1)
58#define REPORT_BIT_AD1 (1 << 2)
59#define REPORT_BIT_HAS_PRESSURE (1 << 6)
60#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
61
Daniel Mack25a70e32009-08-12 00:50:09 -070062static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
63{
64 return gpio_get_value(irq_to_gpio(priv->irq)) == priv->irq_active_high;
65}
66
Daniel Mack10494dc2009-05-18 16:10:39 -070067static void eeti_ts_read(struct work_struct *work)
68{
69 char buf[6];
70 unsigned int x, y, res, pressed, to = 100;
71 struct eeti_ts_priv *priv =
72 container_of(work, struct eeti_ts_priv, work);
73
74 mutex_lock(&priv->mutex);
75
Daniel Mack25a70e32009-08-12 00:50:09 -070076 while (eeti_ts_irq_active(priv) && --to)
Daniel Mack10494dc2009-05-18 16:10:39 -070077 i2c_master_recv(priv->client, buf, sizeof(buf));
78
79 if (!to) {
80 dev_err(&priv->client->dev,
81 "unable to clear IRQ - line stuck?\n");
82 goto out;
83 }
84
85 /* drop non-report packets */
86 if (!(buf[0] & 0x80))
87 goto out;
88
89 pressed = buf[0] & REPORT_BIT_PRESSED;
90 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
91 x = buf[2] | (buf[1] << 8);
92 y = buf[4] | (buf[3] << 8);
93
94 /* fix the range to 11 bits */
95 x >>= res - EETI_TS_BITDEPTH;
96 y >>= res - EETI_TS_BITDEPTH;
97
98 if (flip_x)
99 x = EETI_MAXVAL - x;
100
101 if (flip_y)
102 y = EETI_MAXVAL - y;
103
104 if (buf[0] & REPORT_BIT_HAS_PRESSURE)
105 input_report_abs(priv->input, ABS_PRESSURE, buf[5]);
106
107 input_report_abs(priv->input, ABS_X, x);
108 input_report_abs(priv->input, ABS_Y, y);
109 input_report_key(priv->input, BTN_TOUCH, !!pressed);
110 input_sync(priv->input);
111
112out:
113 mutex_unlock(&priv->mutex);
114}
115
116static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
117{
118 struct eeti_ts_priv *priv = dev_id;
119
120 /* postpone I2C transactions as we are atomic */
121 schedule_work(&priv->work);
122
123 return IRQ_HANDLED;
124}
125
126static int eeti_ts_open(struct input_dev *dev)
127{
128 struct eeti_ts_priv *priv = input_get_drvdata(dev);
129
130 enable_irq(priv->irq);
131
132 /* Read the events once to arm the IRQ */
133 eeti_ts_read(&priv->work);
134
135 return 0;
136}
137
138static void eeti_ts_close(struct input_dev *dev)
139{
140 struct eeti_ts_priv *priv = input_get_drvdata(dev);
141
142 disable_irq(priv->irq);
143 cancel_work_sync(&priv->work);
144}
145
146static int __devinit eeti_ts_probe(struct i2c_client *client,
147 const struct i2c_device_id *idp)
148{
Daniel Mack25a70e32009-08-12 00:50:09 -0700149 struct eeti_ts_platform_data *pdata;
Daniel Mack10494dc2009-05-18 16:10:39 -0700150 struct eeti_ts_priv *priv;
151 struct input_dev *input;
Daniel Mack25a70e32009-08-12 00:50:09 -0700152 unsigned int irq_flags;
Daniel Mack10494dc2009-05-18 16:10:39 -0700153 int err = -ENOMEM;
154
155 /* In contrast to what's described in the datasheet, there seems
156 * to be no way of probing the presence of that device using I2C
157 * commands. So we need to blindly believe it is there, and wait
158 * for interrupts to occur. */
159
160 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
161 if (!priv) {
162 dev_err(&client->dev, "failed to allocate driver data\n");
163 goto err0;
164 }
165
166 mutex_init(&priv->mutex);
167 input = input_allocate_device();
168
169 if (!input) {
170 dev_err(&client->dev, "Failed to allocate input device.\n");
171 goto err1;
172 }
173
174 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
175 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
176
177 input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
178 input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
179 input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
180
181 input->name = client->name;
182 input->id.bustype = BUS_I2C;
183 input->dev.parent = &client->dev;
184 input->open = eeti_ts_open;
185 input->close = eeti_ts_close;
186
187 priv->client = client;
188 priv->input = input;
189 priv->irq = client->irq;
190
Daniel Mack25a70e32009-08-12 00:50:09 -0700191 pdata = client->dev.platform_data;
192
193 if (pdata)
194 priv->irq_active_high = pdata->irq_active_high;
195
196 irq_flags = priv->irq_active_high ?
197 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
198
Daniel Mack10494dc2009-05-18 16:10:39 -0700199 INIT_WORK(&priv->work, eeti_ts_read);
200 i2c_set_clientdata(client, priv);
201 input_set_drvdata(input, priv);
202
203 err = input_register_device(input);
204 if (err)
205 goto err1;
206
Daniel Mack25a70e32009-08-12 00:50:09 -0700207 err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
Daniel Mack10494dc2009-05-18 16:10:39 -0700208 client->name, priv);
209 if (err) {
210 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
211 goto err2;
212 }
213
214 /* Disable the irq for now. It will be enabled once the input device
215 * is opened. */
216 disable_irq(priv->irq);
217
218 device_init_wakeup(&client->dev, 0);
219 return 0;
220
221err2:
222 input_unregister_device(input);
223 input = NULL; /* so we dont try to free it below */
224err1:
225 input_free_device(input);
226 i2c_set_clientdata(client, NULL);
227 kfree(priv);
228err0:
229 return err;
230}
231
232static int __devexit eeti_ts_remove(struct i2c_client *client)
233{
234 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
235
236 free_irq(priv->irq, priv);
237 input_unregister_device(priv->input);
238 i2c_set_clientdata(client, NULL);
239 kfree(priv);
240
241 return 0;
242}
243
244#ifdef CONFIG_PM
245static int eeti_ts_suspend(struct i2c_client *client, pm_message_t mesg)
246{
247 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
248
249 if (device_may_wakeup(&client->dev))
250 enable_irq_wake(priv->irq);
251
252 return 0;
253}
254
255static int eeti_ts_resume(struct i2c_client *client)
256{
257 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
258
259 if (device_may_wakeup(&client->dev))
260 disable_irq_wake(priv->irq);
261
262 return 0;
263}
264#else
265#define eeti_ts_suspend NULL
266#define eeti_ts_resume NULL
267#endif
268
269static const struct i2c_device_id eeti_ts_id[] = {
270 { "eeti_ts", 0 },
271 { }
272};
273MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
274
275static struct i2c_driver eeti_ts_driver = {
276 .driver = {
277 .name = "eeti_ts",
278 },
279 .probe = eeti_ts_probe,
280 .remove = __devexit_p(eeti_ts_remove),
281 .suspend = eeti_ts_suspend,
282 .resume = eeti_ts_resume,
283 .id_table = eeti_ts_id,
284};
285
286static int __init eeti_ts_init(void)
287{
288 return i2c_add_driver(&eeti_ts_driver);
289}
290
291static void __exit eeti_ts_exit(void)
292{
293 i2c_del_driver(&eeti_ts_driver);
294}
295
296MODULE_DESCRIPTION("EETI Touchscreen driver");
297MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
298MODULE_LICENSE("GPL");
299
300module_init(eeti_ts_init);
301module_exit(eeti_ts_exit);
302