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16#include <linux/gpio/consumer.h>
17#include <linux/interrupt.h>
18#include <linux/i2c.h>
19#include <linux/input.h>
20#include <linux/input/mt.h>
21#include <linux/input/touchscreen.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/delay.h>
25
26
27#define EKTF2127_NOISE 0x40
28#define EKTF2127_RESPONSE 0x52
29#define EKTF2127_REQUEST 0x53
30#define EKTF2127_HELLO 0x55
31#define EKTF2127_REPORT2 0x5a
32#define EKTF2127_REPORT 0x5d
33#define EKTF2127_CALIB_DONE 0x66
34
35
36#define EKTF2127_ENV_NOISY 0x41
37#define EKTF2127_HEIGHT 0x60
38#define EKTF2127_WIDTH 0x63
39
40
41#define EKTF2127_TOUCH_REPORT_SIZE 21
42#define EKTF2127_MAX_TOUCHES 5
43
44struct ektf2127_ts {
45 struct i2c_client *client;
46 struct input_dev *input;
47 struct gpio_desc *power_gpios;
48 struct touchscreen_properties prop;
49};
50
51static void ektf2127_parse_coordinates(const u8 *buf, unsigned int touch_count,
52 struct input_mt_pos *touches)
53{
54 int index = 0;
55 int i;
56
57 for (i = 0; i < touch_count; i++) {
58 index = 2 + i * 3;
59
60 touches[i].x = (buf[index] & 0x0f);
61 touches[i].x <<= 8;
62 touches[i].x |= buf[index + 2];
63
64 touches[i].y = (buf[index] & 0xf0);
65 touches[i].y <<= 4;
66 touches[i].y |= buf[index + 1];
67 }
68}
69
70static void ektf2127_report_event(struct ektf2127_ts *ts, const u8 *buf)
71{
72 struct input_mt_pos touches[EKTF2127_MAX_TOUCHES];
73 int slots[EKTF2127_MAX_TOUCHES];
74 unsigned int touch_count, i;
75
76 touch_count = buf[1] & 0x07;
77 if (touch_count > EKTF2127_MAX_TOUCHES) {
78 dev_err(&ts->client->dev,
79 "Too many touches %d > %d\n",
80 touch_count, EKTF2127_MAX_TOUCHES);
81 touch_count = EKTF2127_MAX_TOUCHES;
82 }
83
84 ektf2127_parse_coordinates(buf, touch_count, touches);
85 input_mt_assign_slots(ts->input, slots, touches,
86 touch_count, 0);
87
88 for (i = 0; i < touch_count; i++) {
89 input_mt_slot(ts->input, slots[i]);
90 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
91 touchscreen_report_pos(ts->input, &ts->prop,
92 touches[i].x, touches[i].y, true);
93 }
94
95 input_mt_sync_frame(ts->input);
96 input_sync(ts->input);
97}
98
99static void ektf2127_report2_contact(struct ektf2127_ts *ts, int slot,
100 const u8 *buf, bool active)
101{
102 input_mt_slot(ts->input, slot);
103 input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, active);
104
105 if (active) {
106 int x = (buf[0] & 0xf0) << 4 | buf[1];
107 int y = (buf[0] & 0x0f) << 8 | buf[2];
108
109 touchscreen_report_pos(ts->input, &ts->prop, x, y, true);
110 }
111}
112
113static void ektf2127_report2_event(struct ektf2127_ts *ts, const u8 *buf)
114{
115 ektf2127_report2_contact(ts, 0, &buf[1], !!(buf[7] & 2));
116 ektf2127_report2_contact(ts, 1, &buf[4], !!(buf[7] & 4));
117
118 input_mt_sync_frame(ts->input);
119 input_sync(ts->input);
120}
121
122static irqreturn_t ektf2127_irq(int irq, void *dev_id)
123{
124 struct ektf2127_ts *ts = dev_id;
125 struct device *dev = &ts->client->dev;
126 char buf[EKTF2127_TOUCH_REPORT_SIZE];
127 int ret;
128
129 ret = i2c_master_recv(ts->client, buf, EKTF2127_TOUCH_REPORT_SIZE);
130 if (ret != EKTF2127_TOUCH_REPORT_SIZE) {
131 dev_err(dev, "Error reading touch data: %d\n", ret);
132 goto out;
133 }
134
135 switch (buf[0]) {
136 case EKTF2127_REPORT:
137 ektf2127_report_event(ts, buf);
138 break;
139
140 case EKTF2127_REPORT2:
141 ektf2127_report2_event(ts, buf);
142 break;
143
144 case EKTF2127_NOISE:
145 if (buf[1] == EKTF2127_ENV_NOISY)
146 dev_dbg(dev, "Environment is electrically noisy\n");
147 break;
148
149 case EKTF2127_HELLO:
150 case EKTF2127_CALIB_DONE:
151 break;
152
153 default:
154 dev_err(dev, "Unexpected packet header byte %#02x\n", buf[0]);
155 break;
156 }
157
158out:
159 return IRQ_HANDLED;
160}
161
162static int ektf2127_start(struct input_dev *dev)
163{
164 struct ektf2127_ts *ts = input_get_drvdata(dev);
165
166 enable_irq(ts->client->irq);
167 gpiod_set_value_cansleep(ts->power_gpios, 1);
168
169 return 0;
170}
171
172static void ektf2127_stop(struct input_dev *dev)
173{
174 struct ektf2127_ts *ts = input_get_drvdata(dev);
175
176 disable_irq(ts->client->irq);
177 gpiod_set_value_cansleep(ts->power_gpios, 0);
178}
179
180static int __maybe_unused ektf2127_suspend(struct device *dev)
181{
182 struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
183
184 mutex_lock(&ts->input->mutex);
185 if (input_device_enabled(ts->input))
186 ektf2127_stop(ts->input);
187 mutex_unlock(&ts->input->mutex);
188
189 return 0;
190}
191
192static int __maybe_unused ektf2127_resume(struct device *dev)
193{
194 struct ektf2127_ts *ts = i2c_get_clientdata(to_i2c_client(dev));
195
196 mutex_lock(&ts->input->mutex);
197 if (input_device_enabled(ts->input))
198 ektf2127_start(ts->input);
199 mutex_unlock(&ts->input->mutex);
200
201 return 0;
202}
203
204static SIMPLE_DEV_PM_OPS(ektf2127_pm_ops, ektf2127_suspend,
205 ektf2127_resume);
206
207static int ektf2127_query_dimension(struct i2c_client *client, bool width)
208{
209 struct device *dev = &client->dev;
210 const char *what = width ? "width" : "height";
211 u8 what_code = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
212 u8 buf[4];
213 int ret;
214 int error;
215
216
217 buf[0] = EKTF2127_REQUEST;
218 buf[1] = width ? EKTF2127_WIDTH : EKTF2127_HEIGHT;
219 buf[2] = 0x00;
220 buf[3] = 0x00;
221 ret = i2c_master_send(client, buf, sizeof(buf));
222 if (ret != sizeof(buf)) {
223 error = ret < 0 ? ret : -EIO;
224 dev_err(dev, "Failed to request %s: %d\n", what, error);
225 return error;
226 }
227
228 msleep(20);
229
230
231 ret = i2c_master_recv(client, buf, sizeof(buf));
232 if (ret != sizeof(buf)) {
233 error = ret < 0 ? ret : -EIO;
234 dev_err(dev, "Failed to receive %s data: %d\n", what, error);
235 return error;
236 }
237
238 if (buf[0] != EKTF2127_RESPONSE || buf[1] != what_code) {
239 dev_err(dev, "Unexpected %s data: %#02x %#02x\n",
240 what, buf[0], buf[1]);
241 return -EIO;
242 }
243
244 return (((buf[3] & 0xf0) << 4) | buf[2]) - 1;
245}
246
247static int ektf2127_probe(struct i2c_client *client,
248 const struct i2c_device_id *id)
249{
250 struct device *dev = &client->dev;
251 struct ektf2127_ts *ts;
252 struct input_dev *input;
253 u8 buf[4];
254 int max_x, max_y;
255 int error;
256
257 if (!client->irq) {
258 dev_err(dev, "Error no irq specified\n");
259 return -EINVAL;
260 }
261
262 ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
263 if (!ts)
264 return -ENOMEM;
265
266
267 ts->power_gpios = devm_gpiod_get(dev, "power", GPIOD_OUT_HIGH);
268 if (IS_ERR(ts->power_gpios)) {
269 error = PTR_ERR(ts->power_gpios);
270 if (error != -EPROBE_DEFER)
271 dev_err(dev, "Error getting power gpio: %d\n", error);
272 return error;
273 }
274
275 input = devm_input_allocate_device(dev);
276 if (!input)
277 return -ENOMEM;
278
279 input->name = client->name;
280 input->id.bustype = BUS_I2C;
281 input->open = ektf2127_start;
282 input->close = ektf2127_stop;
283
284 ts->client = client;
285
286
287 msleep(20);
288 i2c_master_recv(ts->client, buf, sizeof(buf));
289
290
291 max_x = ektf2127_query_dimension(client, true);
292 if (max_x < 0)
293 return max_x;
294
295 max_y = ektf2127_query_dimension(client, false);
296 if (max_y < 0)
297 return max_y;
298
299 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
300 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
301 touchscreen_parse_properties(input, true, &ts->prop);
302
303 error = input_mt_init_slots(input, EKTF2127_MAX_TOUCHES,
304 INPUT_MT_DIRECT |
305 INPUT_MT_DROP_UNUSED |
306 INPUT_MT_TRACK);
307 if (error)
308 return error;
309
310 ts->input = input;
311 input_set_drvdata(input, ts);
312
313 error = devm_request_threaded_irq(dev, client->irq,
314 NULL, ektf2127_irq,
315 IRQF_ONESHOT, client->name, ts);
316 if (error) {
317 dev_err(dev, "Error requesting irq: %d\n", error);
318 return error;
319 }
320
321
322 ektf2127_stop(ts->input);
323
324 error = input_register_device(input);
325 if (error)
326 return error;
327
328 i2c_set_clientdata(client, ts);
329
330 return 0;
331}
332
333#ifdef CONFIG_OF
334static const struct of_device_id ektf2127_of_match[] = {
335 { .compatible = "elan,ektf2127" },
336 { .compatible = "elan,ektf2132" },
337 {}
338};
339MODULE_DEVICE_TABLE(of, ektf2127_of_match);
340#endif
341
342static const struct i2c_device_id ektf2127_i2c_id[] = {
343 { "ektf2127", 0 },
344 { "ektf2132", 0 },
345 {}
346};
347MODULE_DEVICE_TABLE(i2c, ektf2127_i2c_id);
348
349static struct i2c_driver ektf2127_driver = {
350 .driver = {
351 .name = "elan_ektf2127",
352 .pm = &ektf2127_pm_ops,
353 .of_match_table = of_match_ptr(ektf2127_of_match),
354 },
355 .probe = ektf2127_probe,
356 .id_table = ektf2127_i2c_id,
357};
358module_i2c_driver(ektf2127_driver);
359
360MODULE_DESCRIPTION("ELAN eKTF2127/eKTF2132 I2C Touchscreen Driver");
361MODULE_AUTHOR("Michel Verlaan, Siebren Vroegindeweij");
362MODULE_LICENSE("GPL");
363
