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1/*
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>
35#include <linux/input/eeti_ts.h>
36#include <linux/slab.h>
37
38static bool flip_x;
39module_param(flip_x, bool, 0644);
40MODULE_PARM_DESC(flip_x, "flip x coordinate");
41
42static bool flip_y;
43module_param(flip_y, bool, 0644);
44MODULE_PARM_DESC(flip_y, "flip y coordinate");
45
46struct eeti_ts_priv {
47 struct i2c_client *client;
48 struct input_dev *input;
49 struct work_struct work;
50 struct mutex mutex;
51 int irq_gpio, irq, irq_active_high;
52};
53
54#define EETI_TS_BITDEPTH (11)
55#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
56
57#define REPORT_BIT_PRESSED (1 << 0)
58#define REPORT_BIT_AD0 (1 << 1)
59#define REPORT_BIT_AD1 (1 << 2)
60#define REPORT_BIT_HAS_PRESSURE (1 << 6)
61#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
62
63static inline int eeti_ts_irq_active(struct eeti_ts_priv *priv)
64{
65 return gpio_get_value(priv->irq_gpio) == priv->irq_active_high;
66}
67
68static void eeti_ts_read(struct work_struct *work)
69{
70 char buf[6];
71 unsigned int x, y, res, pressed, to = 100;
72 struct eeti_ts_priv *priv =
73 container_of(work, struct eeti_ts_priv, work);
74
75 mutex_lock(&priv->mutex);
76
77 while (eeti_ts_irq_active(priv) && --to)
78 i2c_master_recv(priv->client, buf, sizeof(buf));
79
80 if (!to) {
81 dev_err(&priv->client->dev,
82 "unable to clear IRQ - line stuck?\n");
83 goto out;
84 }
85
86 /* drop non-report packets */
87 if (!(buf[0] & 0x80))
88 goto out;
89
90 pressed = buf[0] & REPORT_BIT_PRESSED;
91 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
92 x = buf[2] | (buf[1] << 8);
93 y = buf[4] | (buf[3] << 8);
94
95 /* fix the range to 11 bits */
96 x >>= res - EETI_TS_BITDEPTH;
97 y >>= res - EETI_TS_BITDEPTH;
98
99 if (flip_x)
100 x = EETI_MAXVAL - x;
101
102 if (flip_y)
103 y = EETI_MAXVAL - y;
104
105 if (buf[0] & REPORT_BIT_HAS_PRESSURE)
106 input_report_abs(priv->input, ABS_PRESSURE, buf[5]);
107
108 input_report_abs(priv->input, ABS_X, x);
109 input_report_abs(priv->input, ABS_Y, y);
110 input_report_key(priv->input, BTN_TOUCH, !!pressed);
111 input_sync(priv->input);
112
113out:
114 mutex_unlock(&priv->mutex);
115}
116
117static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
118{
119 struct eeti_ts_priv *priv = dev_id;
120
121 /* postpone I2C transactions as we are atomic */
122 schedule_work(&priv->work);
123
124 return IRQ_HANDLED;
125}
126
127static void eeti_ts_start(struct eeti_ts_priv *priv)
128{
129 enable_irq(priv->irq);
130
131 /* Read the events once to arm the IRQ */
132 eeti_ts_read(&priv->work);
133}
134
135static void eeti_ts_stop(struct eeti_ts_priv *priv)
136{
137 disable_irq(priv->irq);
138 cancel_work_sync(&priv->work);
139}
140
141static int eeti_ts_open(struct input_dev *dev)
142{
143 struct eeti_ts_priv *priv = input_get_drvdata(dev);
144
145 eeti_ts_start(priv);
146
147 return 0;
148}
149
150static void eeti_ts_close(struct input_dev *dev)
151{
152 struct eeti_ts_priv *priv = input_get_drvdata(dev);
153
154 eeti_ts_stop(priv);
155}
156
157static int eeti_ts_probe(struct i2c_client *client,
158 const struct i2c_device_id *idp)
159{
160 struct eeti_ts_platform_data *pdata = dev_get_platdata(&client->dev);
161 struct eeti_ts_priv *priv;
162 struct input_dev *input;
163 unsigned int irq_flags;
164 int err = -ENOMEM;
165
166 /*
167 * In contrast to what's described in the datasheet, there seems
168 * to be no way of probing the presence of that device using I2C
169 * commands. So we need to blindly believe it is there, and wait
170 * for interrupts to occur.
171 */
172
173 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
174 if (!priv) {
175 dev_err(&client->dev, "failed to allocate driver data\n");
176 goto err0;
177 }
178
179 mutex_init(&priv->mutex);
180 input = input_allocate_device();
181
182 if (!input) {
183 dev_err(&client->dev, "Failed to allocate input device.\n");
184 goto err1;
185 }
186
187 input->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
188 input->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
189
190 input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
191 input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
192 input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
193
194 input->name = client->name;
195 input->id.bustype = BUS_I2C;
196 input->dev.parent = &client->dev;
197 input->open = eeti_ts_open;
198 input->close = eeti_ts_close;
199
200 priv->client = client;
201 priv->input = input;
202 priv->irq_gpio = pdata->irq_gpio;
203 priv->irq = gpio_to_irq(pdata->irq_gpio);
204
205 err = gpio_request_one(pdata->irq_gpio, GPIOF_IN, client->name);
206 if (err < 0)
207 goto err1;
208
209 priv->irq_active_high = pdata->irq_active_high;
210
211 irq_flags = priv->irq_active_high ?
212 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
213
214 INIT_WORK(&priv->work, eeti_ts_read);
215 i2c_set_clientdata(client, priv);
216 input_set_drvdata(input, priv);
217
218 err = input_register_device(input);
219 if (err)
220 goto err2;
221
222 err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
223 client->name, priv);
224 if (err) {
225 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
226 goto err3;
227 }
228
229 /*
230 * Disable the device for now. It will be enabled once the
231 * input device is opened.
232 */
233 eeti_ts_stop(priv);
234
235 device_init_wakeup(&client->dev, 0);
236 return 0;
237
238err3:
239 input_unregister_device(input);
240 input = NULL; /* so we dont try to free it below */
241err2:
242 gpio_free(pdata->irq_gpio);
243err1:
244 input_free_device(input);
245 kfree(priv);
246err0:
247 return err;
248}
249
250static int eeti_ts_remove(struct i2c_client *client)
251{
252 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
253
254 free_irq(priv->irq, priv);
255 /*
256 * eeti_ts_stop() leaves IRQ disabled. We need to re-enable it
257 * so that device still works if we reload the driver.
258 */
259 enable_irq(priv->irq);
260
261 input_unregister_device(priv->input);
262 kfree(priv);
263
264 return 0;
265}
266
267static int __maybe_unused eeti_ts_suspend(struct device *dev)
268{
269 struct i2c_client *client = to_i2c_client(dev);
270 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
271 struct input_dev *input_dev = priv->input;
272
273 mutex_lock(&input_dev->mutex);
274
275 if (input_dev->users)
276 eeti_ts_stop(priv);
277
278 mutex_unlock(&input_dev->mutex);
279
280 if (device_may_wakeup(&client->dev))
281 enable_irq_wake(priv->irq);
282
283 return 0;
284}
285
286static int __maybe_unused eeti_ts_resume(struct device *dev)
287{
288 struct i2c_client *client = to_i2c_client(dev);
289 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
290 struct input_dev *input_dev = priv->input;
291
292 if (device_may_wakeup(&client->dev))
293 disable_irq_wake(priv->irq);
294
295 mutex_lock(&input_dev->mutex);
296
297 if (input_dev->users)
298 eeti_ts_start(priv);
299
300 mutex_unlock(&input_dev->mutex);
301
302 return 0;
303}
304
305static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
306
307static const struct i2c_device_id eeti_ts_id[] = {
308 { "eeti_ts", 0 },
309 { }
310};
311MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
312
313static struct i2c_driver eeti_ts_driver = {
314 .driver = {
315 .name = "eeti_ts",
316 .pm = &eeti_ts_pm,
317 },
318 .probe = eeti_ts_probe,
319 .remove = eeti_ts_remove,
320 .id_table = eeti_ts_id,
321};
322
323module_i2c_driver(eeti_ts_driver);
324
325MODULE_DESCRIPTION("EETI Touchscreen driver");
326MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
327MODULE_LICENSE("GPL");
1/*
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/consumer.h>
35#include <linux/slab.h>
36#include <asm/unaligned.h>
37
38static bool flip_x;
39module_param(flip_x, bool, 0644);
40MODULE_PARM_DESC(flip_x, "flip x coordinate");
41
42static bool flip_y;
43module_param(flip_y, bool, 0644);
44MODULE_PARM_DESC(flip_y, "flip y coordinate");
45
46struct eeti_ts {
47 struct i2c_client *client;
48 struct input_dev *input;
49 struct gpio_desc *attn_gpio;
50 bool running;
51};
52
53#define EETI_TS_BITDEPTH (11)
54#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
55
56#define REPORT_BIT_PRESSED BIT(0)
57#define REPORT_BIT_AD0 BIT(1)
58#define REPORT_BIT_AD1 BIT(2)
59#define REPORT_BIT_HAS_PRESSURE BIT(6)
60#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
61
62static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
63{
64 unsigned int res;
65 u16 x, y;
66
67 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
68
69 x = get_unaligned_be16(&buf[1]);
70 y = get_unaligned_be16(&buf[3]);
71
72 /* fix the range to 11 bits */
73 x >>= res - EETI_TS_BITDEPTH;
74 y >>= res - EETI_TS_BITDEPTH;
75
76 if (flip_x)
77 x = EETI_MAXVAL - x;
78
79 if (flip_y)
80 y = EETI_MAXVAL - y;
81
82 if (buf[0] & REPORT_BIT_HAS_PRESSURE)
83 input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
84
85 input_report_abs(eeti->input, ABS_X, x);
86 input_report_abs(eeti->input, ABS_Y, y);
87 input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
88 input_sync(eeti->input);
89}
90
91static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
92{
93 struct eeti_ts *eeti = dev_id;
94 int len;
95 int error;
96 char buf[6];
97
98 do {
99 len = i2c_master_recv(eeti->client, buf, sizeof(buf));
100 if (len != sizeof(buf)) {
101 error = len < 0 ? len : -EIO;
102 dev_err(&eeti->client->dev,
103 "failed to read touchscreen data: %d\n",
104 error);
105 break;
106 }
107
108 if (buf[0] & 0x80) {
109 /* Motion packet */
110 eeti_ts_report_event(eeti, buf);
111 }
112 } while (eeti->running &&
113 eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio));
114
115 return IRQ_HANDLED;
116}
117
118static void eeti_ts_start(struct eeti_ts *eeti)
119{
120 eeti->running = true;
121 wmb();
122 enable_irq(eeti->client->irq);
123}
124
125static void eeti_ts_stop(struct eeti_ts *eeti)
126{
127 eeti->running = false;
128 wmb();
129 disable_irq(eeti->client->irq);
130}
131
132static int eeti_ts_open(struct input_dev *dev)
133{
134 struct eeti_ts *eeti = input_get_drvdata(dev);
135
136 eeti_ts_start(eeti);
137
138 return 0;
139}
140
141static void eeti_ts_close(struct input_dev *dev)
142{
143 struct eeti_ts *eeti = input_get_drvdata(dev);
144
145 eeti_ts_stop(eeti);
146}
147
148static int eeti_ts_probe(struct i2c_client *client,
149 const struct i2c_device_id *idp)
150{
151 struct device *dev = &client->dev;
152 struct eeti_ts *eeti;
153 struct input_dev *input;
154 int error;
155
156 /*
157 * In contrast to what's described in the datasheet, there seems
158 * to be no way of probing the presence of that device using I2C
159 * commands. So we need to blindly believe it is there, and wait
160 * for interrupts to occur.
161 */
162
163 eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
164 if (!eeti) {
165 dev_err(dev, "failed to allocate driver data\n");
166 return -ENOMEM;
167 }
168
169 input = devm_input_allocate_device(dev);
170 if (!input) {
171 dev_err(dev, "Failed to allocate input device.\n");
172 return -ENOMEM;
173 }
174
175 input_set_capability(input, EV_KEY, 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->open = eeti_ts_open;
184 input->close = eeti_ts_close;
185
186 eeti->client = client;
187 eeti->input = input;
188
189 eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
190 if (IS_ERR(eeti->attn_gpio))
191 return PTR_ERR(eeti->attn_gpio);
192
193 i2c_set_clientdata(client, eeti);
194 input_set_drvdata(input, eeti);
195
196 error = devm_request_threaded_irq(dev, client->irq,
197 NULL, eeti_ts_isr,
198 IRQF_ONESHOT,
199 client->name, eeti);
200 if (error) {
201 dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
202 error);
203 return error;
204 }
205
206 /*
207 * Disable the device for now. It will be enabled once the
208 * input device is opened.
209 */
210 eeti_ts_stop(eeti);
211
212 error = input_register_device(input);
213 if (error)
214 return error;
215
216 return 0;
217}
218
219static int __maybe_unused eeti_ts_suspend(struct device *dev)
220{
221 struct i2c_client *client = to_i2c_client(dev);
222 struct eeti_ts *eeti = i2c_get_clientdata(client);
223 struct input_dev *input_dev = eeti->input;
224
225 mutex_lock(&input_dev->mutex);
226
227 if (input_dev->users)
228 eeti_ts_stop(eeti);
229
230 mutex_unlock(&input_dev->mutex);
231
232 if (device_may_wakeup(&client->dev))
233 enable_irq_wake(client->irq);
234
235 return 0;
236}
237
238static int __maybe_unused eeti_ts_resume(struct device *dev)
239{
240 struct i2c_client *client = to_i2c_client(dev);
241 struct eeti_ts *eeti = i2c_get_clientdata(client);
242 struct input_dev *input_dev = eeti->input;
243
244 if (device_may_wakeup(&client->dev))
245 disable_irq_wake(client->irq);
246
247 mutex_lock(&input_dev->mutex);
248
249 if (input_dev->users)
250 eeti_ts_start(eeti);
251
252 mutex_unlock(&input_dev->mutex);
253
254 return 0;
255}
256
257static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
258
259static const struct i2c_device_id eeti_ts_id[] = {
260 { "eeti_ts", 0 },
261 { }
262};
263MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
264
265static struct i2c_driver eeti_ts_driver = {
266 .driver = {
267 .name = "eeti_ts",
268 .pm = &eeti_ts_pm,
269 },
270 .probe = eeti_ts_probe,
271 .id_table = eeti_ts_id,
272};
273
274module_i2c_driver(eeti_ts_driver);
275
276MODULE_DESCRIPTION("EETI Touchscreen driver");
277MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
278MODULE_LICENSE("GPL");