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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 <linux/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 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 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 DEFINE_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" },
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 = pm_sleep_ptr(&eeti_ts_pm),
292 .of_match_table = of_match_ptr(of_eeti_ts_match),
293 },
294 .probe = 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/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");