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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Touch Screen driver for EETI's I2C connected touch screen panels
4 * Copyright (c) 2009,2018 Daniel Mack <daniel@zonque.org>
5 *
6 * See EETI's software guide for the protocol specification:
7 * http://home.eeti.com.tw/documentation.html
8 *
9 * Based on migor_ts.c
10 * Copyright (c) 2008 Magnus Damm
11 * Copyright (c) 2007 Ujjwal Pande <ujjwal@kenati.com>
12 */
13
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/input.h>
17#include <linux/input/touchscreen.h>
18#include <linux/interrupt.h>
19#include <linux/i2c.h>
20#include <linux/timer.h>
21#include <linux/gpio/consumer.h>
22#include <linux/of.h>
23#include <linux/slab.h>
24#include <asm/unaligned.h>
25
26struct eeti_ts {
27 struct i2c_client *client;
28 struct input_dev *input;
29 struct gpio_desc *attn_gpio;
30 struct touchscreen_properties props;
31 struct mutex mutex;
32 bool running;
33};
34
35#define EETI_TS_BITDEPTH (11)
36#define EETI_MAXVAL ((1 << (EETI_TS_BITDEPTH + 1)) - 1)
37
38#define REPORT_BIT_PRESSED BIT(0)
39#define REPORT_BIT_AD0 BIT(1)
40#define REPORT_BIT_AD1 BIT(2)
41#define REPORT_BIT_HAS_PRESSURE BIT(6)
42#define REPORT_RES_BITS(v) (((v) >> 1) + EETI_TS_BITDEPTH)
43
44static void eeti_ts_report_event(struct eeti_ts *eeti, u8 *buf)
45{
46 unsigned int res;
47 u16 x, y;
48
49 res = REPORT_RES_BITS(buf[0] & (REPORT_BIT_AD0 | REPORT_BIT_AD1));
50
51 x = get_unaligned_be16(&buf[1]);
52 y = get_unaligned_be16(&buf[3]);
53
54 /* fix the range to 11 bits */
55 x >>= res - EETI_TS_BITDEPTH;
56 y >>= res - EETI_TS_BITDEPTH;
57
58 if (buf[0] & REPORT_BIT_HAS_PRESSURE)
59 input_report_abs(eeti->input, ABS_PRESSURE, buf[5]);
60
61 touchscreen_report_pos(eeti->input, &eeti->props, x, y, false);
62 input_report_key(eeti->input, BTN_TOUCH, buf[0] & REPORT_BIT_PRESSED);
63 input_sync(eeti->input);
64}
65
66static int eeti_ts_read(struct eeti_ts *eeti)
67{
68 int len, error;
69 char buf[6];
70
71 len = i2c_master_recv(eeti->client, buf, sizeof(buf));
72 if (len != sizeof(buf)) {
73 error = len < 0 ? len : -EIO;
74 dev_err(&eeti->client->dev,
75 "failed to read touchscreen data: %d\n",
76 error);
77 return error;
78 }
79
80 /* Motion packet */
81 if (buf[0] & 0x80)
82 eeti_ts_report_event(eeti, buf);
83
84 return 0;
85}
86
87static irqreturn_t eeti_ts_isr(int irq, void *dev_id)
88{
89 struct eeti_ts *eeti = dev_id;
90 int error;
91
92 mutex_lock(&eeti->mutex);
93
94 do {
95 /*
96 * If we have attention GPIO, trust it. Otherwise we'll read
97 * once and exit. We assume that in this case we are using
98 * level triggered interrupt and it will get raised again
99 * if/when there is more data.
100 */
101 if (eeti->attn_gpio &&
102 !gpiod_get_value_cansleep(eeti->attn_gpio)) {
103 break;
104 }
105
106 error = eeti_ts_read(eeti);
107 if (error)
108 break;
109
110 } while (eeti->running && eeti->attn_gpio);
111
112 mutex_unlock(&eeti->mutex);
113 return IRQ_HANDLED;
114}
115
116static void eeti_ts_start(struct eeti_ts *eeti)
117{
118 mutex_lock(&eeti->mutex);
119
120 eeti->running = true;
121 enable_irq(eeti->client->irq);
122
123 /*
124 * Kick the controller in case we are using edge interrupt and
125 * we missed our edge while interrupt was disabled. We expect
126 * the attention GPIO to be wired in this case.
127 */
128 if (eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio))
129 eeti_ts_read(eeti);
130
131 mutex_unlock(&eeti->mutex);
132}
133
134static void eeti_ts_stop(struct eeti_ts *eeti)
135{
136 /*
137 * Not locking here, just setting a flag and expect that the
138 * interrupt thread will notice the flag eventually.
139 */
140 eeti->running = false;
141 wmb();
142 disable_irq(eeti->client->irq);
143}
144
145static int eeti_ts_open(struct input_dev *dev)
146{
147 struct eeti_ts *eeti = input_get_drvdata(dev);
148
149 eeti_ts_start(eeti);
150
151 return 0;
152}
153
154static void eeti_ts_close(struct input_dev *dev)
155{
156 struct eeti_ts *eeti = input_get_drvdata(dev);
157
158 eeti_ts_stop(eeti);
159}
160
161static int eeti_ts_probe(struct i2c_client *client)
162{
163 struct device *dev = &client->dev;
164 struct eeti_ts *eeti;
165 struct input_dev *input;
166 int error;
167
168 /*
169 * In contrast to what's described in the datasheet, there seems
170 * to be no way of probing the presence of that device using I2C
171 * commands. So we need to blindly believe it is there, and wait
172 * for interrupts to occur.
173 */
174
175 eeti = devm_kzalloc(dev, sizeof(*eeti), GFP_KERNEL);
176 if (!eeti) {
177 dev_err(dev, "failed to allocate driver data\n");
178 return -ENOMEM;
179 }
180
181 mutex_init(&eeti->mutex);
182
183 input = devm_input_allocate_device(dev);
184 if (!input) {
185 dev_err(dev, "Failed to allocate input device.\n");
186 return -ENOMEM;
187 }
188
189 input_set_capability(input, EV_KEY, BTN_TOUCH);
190
191 input_set_abs_params(input, ABS_X, 0, EETI_MAXVAL, 0, 0);
192 input_set_abs_params(input, ABS_Y, 0, EETI_MAXVAL, 0, 0);
193 input_set_abs_params(input, ABS_PRESSURE, 0, 0xff, 0, 0);
194
195 touchscreen_parse_properties(input, false, &eeti->props);
196
197 input->name = client->name;
198 input->id.bustype = BUS_I2C;
199 input->open = eeti_ts_open;
200 input->close = eeti_ts_close;
201
202 eeti->client = client;
203 eeti->input = input;
204
205 eeti->attn_gpio = devm_gpiod_get_optional(dev, "attn", GPIOD_IN);
206 if (IS_ERR(eeti->attn_gpio))
207 return PTR_ERR(eeti->attn_gpio);
208
209 i2c_set_clientdata(client, eeti);
210 input_set_drvdata(input, eeti);
211
212 error = devm_request_threaded_irq(dev, client->irq,
213 NULL, eeti_ts_isr,
214 IRQF_ONESHOT,
215 client->name, eeti);
216 if (error) {
217 dev_err(dev, "Unable to request touchscreen IRQ: %d\n",
218 error);
219 return error;
220 }
221
222 /*
223 * Disable the device for now. It will be enabled once the
224 * input device is opened.
225 */
226 eeti_ts_stop(eeti);
227
228 error = input_register_device(input);
229 if (error)
230 return error;
231
232 return 0;
233}
234
235static int __maybe_unused eeti_ts_suspend(struct device *dev)
236{
237 struct i2c_client *client = to_i2c_client(dev);
238 struct eeti_ts *eeti = i2c_get_clientdata(client);
239 struct input_dev *input_dev = eeti->input;
240
241 mutex_lock(&input_dev->mutex);
242
243 if (input_device_enabled(input_dev))
244 eeti_ts_stop(eeti);
245
246 mutex_unlock(&input_dev->mutex);
247
248 if (device_may_wakeup(&client->dev))
249 enable_irq_wake(client->irq);
250
251 return 0;
252}
253
254static int __maybe_unused eeti_ts_resume(struct device *dev)
255{
256 struct i2c_client *client = to_i2c_client(dev);
257 struct eeti_ts *eeti = i2c_get_clientdata(client);
258 struct input_dev *input_dev = eeti->input;
259
260 if (device_may_wakeup(&client->dev))
261 disable_irq_wake(client->irq);
262
263 mutex_lock(&input_dev->mutex);
264
265 if (input_device_enabled(input_dev))
266 eeti_ts_start(eeti);
267
268 mutex_unlock(&input_dev->mutex);
269
270 return 0;
271}
272
273static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
274
275static const struct i2c_device_id eeti_ts_id[] = {
276 { "eeti_ts", 0 },
277 { }
278};
279MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
280
281#ifdef CONFIG_OF
282static const struct of_device_id of_eeti_ts_match[] = {
283 { .compatible = "eeti,exc3000-i2c", },
284 { }
285};
286#endif
287
288static struct i2c_driver eeti_ts_driver = {
289 .driver = {
290 .name = "eeti_ts",
291 .pm = &eeti_ts_pm,
292 .of_match_table = of_match_ptr(of_eeti_ts_match),
293 },
294 .probe_new = eeti_ts_probe,
295 .id_table = eeti_ts_id,
296};
297
298module_i2c_driver(eeti_ts_driver);
299
300MODULE_DESCRIPTION("EETI Touchscreen driver");
301MODULE_AUTHOR("Daniel Mack <daniel@zonque.org>");
302MODULE_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.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 __devinit eeti_ts_probe(struct i2c_client *client,
158 const struct i2c_device_id *idp)
159{
160 struct eeti_ts_platform_data *pdata = client->dev.platform_data;
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 if (pdata)
210 priv->irq_active_high = pdata->irq_active_high;
211
212 irq_flags = priv->irq_active_high ?
213 IRQF_TRIGGER_RISING : IRQF_TRIGGER_FALLING;
214
215 INIT_WORK(&priv->work, eeti_ts_read);
216 i2c_set_clientdata(client, priv);
217 input_set_drvdata(input, priv);
218
219 err = input_register_device(input);
220 if (err)
221 goto err2;
222
223 err = request_irq(priv->irq, eeti_ts_isr, irq_flags,
224 client->name, priv);
225 if (err) {
226 dev_err(&client->dev, "Unable to request touchscreen IRQ.\n");
227 goto err3;
228 }
229
230 /*
231 * Disable the device for now. It will be enabled once the
232 * input device is opened.
233 */
234 eeti_ts_stop(priv);
235
236 device_init_wakeup(&client->dev, 0);
237 return 0;
238
239err3:
240 input_unregister_device(input);
241 input = NULL; /* so we dont try to free it below */
242err2:
243 gpio_free(pdata->irq_gpio);
244err1:
245 input_free_device(input);
246 kfree(priv);
247err0:
248 return err;
249}
250
251static int __devexit eeti_ts_remove(struct i2c_client *client)
252{
253 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
254
255 free_irq(priv->irq, priv);
256 /*
257 * eeti_ts_stop() leaves IRQ disabled. We need to re-enable it
258 * so that device still works if we reload the driver.
259 */
260 enable_irq(priv->irq);
261
262 input_unregister_device(priv->input);
263 kfree(priv);
264
265 return 0;
266}
267
268#ifdef CONFIG_PM
269static int eeti_ts_suspend(struct device *dev)
270{
271 struct i2c_client *client = to_i2c_client(dev);
272 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
273 struct input_dev *input_dev = priv->input;
274
275 mutex_lock(&input_dev->mutex);
276
277 if (input_dev->users)
278 eeti_ts_stop(priv);
279
280 mutex_unlock(&input_dev->mutex);
281
282 if (device_may_wakeup(&client->dev))
283 enable_irq_wake(priv->irq);
284
285 return 0;
286}
287
288static int eeti_ts_resume(struct device *dev)
289{
290 struct i2c_client *client = to_i2c_client(dev);
291 struct eeti_ts_priv *priv = i2c_get_clientdata(client);
292 struct input_dev *input_dev = priv->input;
293
294 if (device_may_wakeup(&client->dev))
295 disable_irq_wake(priv->irq);
296
297 mutex_lock(&input_dev->mutex);
298
299 if (input_dev->users)
300 eeti_ts_start(priv);
301
302 mutex_unlock(&input_dev->mutex);
303
304 return 0;
305}
306
307static SIMPLE_DEV_PM_OPS(eeti_ts_pm, eeti_ts_suspend, eeti_ts_resume);
308#endif
309
310static const struct i2c_device_id eeti_ts_id[] = {
311 { "eeti_ts", 0 },
312 { }
313};
314MODULE_DEVICE_TABLE(i2c, eeti_ts_id);
315
316static struct i2c_driver eeti_ts_driver = {
317 .driver = {
318 .name = "eeti_ts",
319#ifdef CONFIG_PM
320 .pm = &eeti_ts_pm,
321#endif
322 },
323 .probe = eeti_ts_probe,
324 .remove = __devexit_p(eeti_ts_remove),
325 .id_table = eeti_ts_id,
326};
327
328module_i2c_driver(eeti_ts_driver);
329
330MODULE_DESCRIPTION("EETI Touchscreen driver");
331MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
332MODULE_LICENSE("GPL");