1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/delay.h>
3 #include <linux/gpio/consumer.h>
4 #include <linux/i2c.h>
5 #include <linux/input.h>
6 #include <linux/input/mt.h>
7 #include <linux/input/touchscreen.h>
8 #include <linux/interrupt.h>
9 #include <linux/module.h>
10 #include <linux/of_device.h>
11 #include <linux/sizes.h>
12 #include <linux/slab.h>
13 #include <asm/unaligned.h>
14
15 #define ILI2XXX_POLL_PERIOD 20
16
17 #define ILI210X_DATA_SIZE 64
18 #define ILI211X_DATA_SIZE 43
19 #define ILI251X_DATA_SIZE1 31
20 #define ILI251X_DATA_SIZE2 20
21
22 /* Touchscreen commands */
23 #define REG_TOUCHDATA 0x10
24 #define REG_PANEL_INFO 0x20
25 #define REG_CALIBRATE 0xcc
26
27 struct ili2xxx_chip {
28 int (*read_reg)(struct i2c_client *client, u8 reg,
29 void *buf, size_t len);
30 int (*get_touch_data)(struct i2c_client *client, u8 *data);
31 bool (*parse_touch_data)(const u8 *data, unsigned int finger,
32 unsigned int *x, unsigned int *y);
33 bool (*continue_polling)(const u8 *data, bool touch);
34 unsigned int max_touches;
35 unsigned int resolution;
36 bool has_calibrate_reg;
37 };
38
39 struct ili210x {
40 struct i2c_client *client;
41 struct input_dev *input;
42 struct gpio_desc *reset_gpio;
43 struct touchscreen_properties prop;
44 const struct ili2xxx_chip *chip;
45 bool stop;
46 };
47
ili210x_read_reg(struct i2c_client * client,u8 reg,void * buf,size_t len)48 static int ili210x_read_reg(struct i2c_client *client,
49 u8 reg, void *buf, size_t len)
50 {
51 struct i2c_msg msg[] = {
52 {
53 .addr = client->addr,
54 .flags = 0,
55 .len = 1,
56 .buf = ®,
57 },
58 {
59 .addr = client->addr,
60 .flags = I2C_M_RD,
61 .len = len,
62 .buf = buf,
63 }
64 };
65 int error, ret;
66
67 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
68 if (ret != ARRAY_SIZE(msg)) {
69 error = ret < 0 ? ret : -EIO;
70 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
71 return error;
72 }
73
74 return 0;
75 }
76
ili210x_read_touch_data(struct i2c_client * client,u8 * data)77 static int ili210x_read_touch_data(struct i2c_client *client, u8 *data)
78 {
79 return ili210x_read_reg(client, REG_TOUCHDATA,
80 data, ILI210X_DATA_SIZE);
81 }
82
ili210x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y)83 static bool ili210x_touchdata_to_coords(const u8 *touchdata,
84 unsigned int finger,
85 unsigned int *x, unsigned int *y)
86 {
87 if (touchdata[0] & BIT(finger))
88 return false;
89
90 *x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
91 *y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
92
93 return true;
94 }
95
ili210x_check_continue_polling(const u8 * data,bool touch)96 static bool ili210x_check_continue_polling(const u8 *data, bool touch)
97 {
98 return data[0] & 0xf3;
99 }
100
101 static const struct ili2xxx_chip ili210x_chip = {
102 .read_reg = ili210x_read_reg,
103 .get_touch_data = ili210x_read_touch_data,
104 .parse_touch_data = ili210x_touchdata_to_coords,
105 .continue_polling = ili210x_check_continue_polling,
106 .max_touches = 2,
107 .has_calibrate_reg = true,
108 };
109
ili211x_read_touch_data(struct i2c_client * client,u8 * data)110 static int ili211x_read_touch_data(struct i2c_client *client, u8 *data)
111 {
112 s16 sum = 0;
113 int error;
114 int ret;
115 int i;
116
117 ret = i2c_master_recv(client, data, ILI211X_DATA_SIZE);
118 if (ret != ILI211X_DATA_SIZE) {
119 error = ret < 0 ? ret : -EIO;
120 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
121 return error;
122 }
123
124 /* This chip uses custom checksum at the end of data */
125 for (i = 0; i < ILI211X_DATA_SIZE - 1; i++)
126 sum = (sum + data[i]) & 0xff;
127
128 if ((-sum & 0xff) != data[ILI211X_DATA_SIZE - 1]) {
129 dev_err(&client->dev,
130 "CRC error (crc=0x%02x expected=0x%02x)\n",
131 sum, data[ILI211X_DATA_SIZE - 1]);
132 return -EIO;
133 }
134
135 return 0;
136 }
137
ili211x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y)138 static bool ili211x_touchdata_to_coords(const u8 *touchdata,
139 unsigned int finger,
140 unsigned int *x, unsigned int *y)
141 {
142 u32 data;
143
144 data = get_unaligned_be32(touchdata + 1 + (finger * 4) + 0);
145 if (data == 0xffffffff) /* Finger up */
146 return false;
147
148 *x = ((touchdata[1 + (finger * 4) + 0] & 0xf0) << 4) |
149 touchdata[1 + (finger * 4) + 1];
150 *y = ((touchdata[1 + (finger * 4) + 0] & 0x0f) << 8) |
151 touchdata[1 + (finger * 4) + 2];
152
153 return true;
154 }
155
ili211x_decline_polling(const u8 * data,bool touch)156 static bool ili211x_decline_polling(const u8 *data, bool touch)
157 {
158 return false;
159 }
160
161 static const struct ili2xxx_chip ili211x_chip = {
162 .read_reg = ili210x_read_reg,
163 .get_touch_data = ili211x_read_touch_data,
164 .parse_touch_data = ili211x_touchdata_to_coords,
165 .continue_polling = ili211x_decline_polling,
166 .max_touches = 10,
167 .resolution = 2048,
168 };
169
ili212x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y)170 static bool ili212x_touchdata_to_coords(const u8 *touchdata,
171 unsigned int finger,
172 unsigned int *x, unsigned int *y)
173 {
174 u16 val;
175
176 val = get_unaligned_be16(touchdata + 3 + (finger * 5) + 0);
177 if (!(val & BIT(15))) /* Touch indication */
178 return false;
179
180 *x = val & 0x3fff;
181 *y = get_unaligned_be16(touchdata + 3 + (finger * 5) + 2);
182
183 return true;
184 }
185
ili212x_check_continue_polling(const u8 * data,bool touch)186 static bool ili212x_check_continue_polling(const u8 *data, bool touch)
187 {
188 return touch;
189 }
190
191 static const struct ili2xxx_chip ili212x_chip = {
192 .read_reg = ili210x_read_reg,
193 .get_touch_data = ili210x_read_touch_data,
194 .parse_touch_data = ili212x_touchdata_to_coords,
195 .continue_polling = ili212x_check_continue_polling,
196 .max_touches = 10,
197 .has_calibrate_reg = true,
198 };
199
ili251x_read_reg(struct i2c_client * client,u8 reg,void * buf,size_t len)200 static int ili251x_read_reg(struct i2c_client *client,
201 u8 reg, void *buf, size_t len)
202 {
203 int error;
204 int ret;
205
206 ret = i2c_master_send(client, ®, 1);
207 if (ret == 1) {
208 usleep_range(5000, 5500);
209
210 ret = i2c_master_recv(client, buf, len);
211 if (ret == len)
212 return 0;
213 }
214
215 error = ret < 0 ? ret : -EIO;
216 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
217 return ret;
218 }
219
ili251x_read_touch_data(struct i2c_client * client,u8 * data)220 static int ili251x_read_touch_data(struct i2c_client *client, u8 *data)
221 {
222 int error;
223
224 error = ili251x_read_reg(client, REG_TOUCHDATA,
225 data, ILI251X_DATA_SIZE1);
226 if (!error && data[0] == 2) {
227 error = i2c_master_recv(client, data + ILI251X_DATA_SIZE1,
228 ILI251X_DATA_SIZE2);
229 if (error >= 0 && error != ILI251X_DATA_SIZE2)
230 error = -EIO;
231 }
232
233 return error;
234 }
235
ili251x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y)236 static bool ili251x_touchdata_to_coords(const u8 *touchdata,
237 unsigned int finger,
238 unsigned int *x, unsigned int *y)
239 {
240 u16 val;
241
242 val = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
243 if (!(val & BIT(15))) /* Touch indication */
244 return false;
245
246 *x = val & 0x3fff;
247 *y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
248
249 return true;
250 }
251
ili251x_check_continue_polling(const u8 * data,bool touch)252 static bool ili251x_check_continue_polling(const u8 *data, bool touch)
253 {
254 return touch;
255 }
256
257 static const struct ili2xxx_chip ili251x_chip = {
258 .read_reg = ili251x_read_reg,
259 .get_touch_data = ili251x_read_touch_data,
260 .parse_touch_data = ili251x_touchdata_to_coords,
261 .continue_polling = ili251x_check_continue_polling,
262 .max_touches = 10,
263 .has_calibrate_reg = true,
264 };
265
ili210x_report_events(struct ili210x * priv,u8 * touchdata)266 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
267 {
268 struct input_dev *input = priv->input;
269 int i;
270 bool contact = false, touch;
271 unsigned int x = 0, y = 0;
272
273 for (i = 0; i < priv->chip->max_touches; i++) {
274 touch = priv->chip->parse_touch_data(touchdata, i, &x, &y);
275
276 input_mt_slot(input, i);
277 if (input_mt_report_slot_state(input, MT_TOOL_FINGER, touch)) {
278 touchscreen_report_pos(input, &priv->prop, x, y, true);
279 contact = true;
280 }
281 }
282
283 input_mt_report_pointer_emulation(input, false);
284 input_sync(input);
285
286 return contact;
287 }
288
ili210x_irq(int irq,void * irq_data)289 static irqreturn_t ili210x_irq(int irq, void *irq_data)
290 {
291 struct ili210x *priv = irq_data;
292 struct i2c_client *client = priv->client;
293 const struct ili2xxx_chip *chip = priv->chip;
294 u8 touchdata[ILI210X_DATA_SIZE] = { 0 };
295 bool keep_polling;
296 bool touch;
297 int error;
298
299 do {
300 error = chip->get_touch_data(client, touchdata);
301 if (error) {
302 dev_err(&client->dev,
303 "Unable to get touch data: %d\n", error);
304 break;
305 }
306
307 touch = ili210x_report_events(priv, touchdata);
308 keep_polling = chip->continue_polling(touchdata, touch);
309 if (keep_polling)
310 msleep(ILI2XXX_POLL_PERIOD);
311 } while (!priv->stop && keep_polling);
312
313 return IRQ_HANDLED;
314 }
315
ili210x_calibrate(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)316 static ssize_t ili210x_calibrate(struct device *dev,
317 struct device_attribute *attr,
318 const char *buf, size_t count)
319 {
320 struct i2c_client *client = to_i2c_client(dev);
321 struct ili210x *priv = i2c_get_clientdata(client);
322 unsigned long calibrate;
323 int rc;
324 u8 cmd = REG_CALIBRATE;
325
326 if (kstrtoul(buf, 10, &calibrate))
327 return -EINVAL;
328
329 if (calibrate > 1)
330 return -EINVAL;
331
332 if (calibrate) {
333 rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
334 if (rc != sizeof(cmd))
335 return -EIO;
336 }
337
338 return count;
339 }
340 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
341
342 static struct attribute *ili210x_attributes[] = {
343 &dev_attr_calibrate.attr,
344 NULL,
345 };
346
ili210x_calibrate_visible(struct kobject * kobj,struct attribute * attr,int index)347 static umode_t ili210x_calibrate_visible(struct kobject *kobj,
348 struct attribute *attr, int index)
349 {
350 struct device *dev = kobj_to_dev(kobj);
351 struct i2c_client *client = to_i2c_client(dev);
352 struct ili210x *priv = i2c_get_clientdata(client);
353
354 return priv->chip->has_calibrate_reg ? attr->mode : 0;
355 }
356
357 static const struct attribute_group ili210x_attr_group = {
358 .attrs = ili210x_attributes,
359 .is_visible = ili210x_calibrate_visible,
360 };
361
ili210x_power_down(void * data)362 static void ili210x_power_down(void *data)
363 {
364 struct gpio_desc *reset_gpio = data;
365
366 gpiod_set_value_cansleep(reset_gpio, 1);
367 }
368
ili210x_stop(void * data)369 static void ili210x_stop(void *data)
370 {
371 struct ili210x *priv = data;
372
373 /* Tell ISR to quit even if there is a contact. */
374 priv->stop = true;
375 }
376
ili210x_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)377 static int ili210x_i2c_probe(struct i2c_client *client,
378 const struct i2c_device_id *id)
379 {
380 struct device *dev = &client->dev;
381 const struct ili2xxx_chip *chip;
382 struct ili210x *priv;
383 struct gpio_desc *reset_gpio;
384 struct input_dev *input;
385 int error;
386 unsigned int max_xy;
387
388 dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
389
390 chip = device_get_match_data(dev);
391 if (!chip && id)
392 chip = (const struct ili2xxx_chip *)id->driver_data;
393 if (!chip) {
394 dev_err(&client->dev, "unknown device model\n");
395 return -ENODEV;
396 }
397
398 if (client->irq <= 0) {
399 dev_err(dev, "No IRQ!\n");
400 return -EINVAL;
401 }
402
403 reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
404 if (IS_ERR(reset_gpio))
405 return PTR_ERR(reset_gpio);
406
407 if (reset_gpio) {
408 error = devm_add_action_or_reset(dev, ili210x_power_down,
409 reset_gpio);
410 if (error)
411 return error;
412
413 usleep_range(50, 100);
414 gpiod_set_value_cansleep(reset_gpio, 0);
415 msleep(100);
416 }
417
418 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
419 if (!priv)
420 return -ENOMEM;
421
422 input = devm_input_allocate_device(dev);
423 if (!input)
424 return -ENOMEM;
425
426 priv->client = client;
427 priv->input = input;
428 priv->reset_gpio = reset_gpio;
429 priv->chip = chip;
430 i2c_set_clientdata(client, priv);
431
432 /* Setup input device */
433 input->name = "ILI210x Touchscreen";
434 input->id.bustype = BUS_I2C;
435
436 /* Multi touch */
437 max_xy = (chip->resolution ?: SZ_64K) - 1;
438 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
439 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
440 touchscreen_parse_properties(input, true, &priv->prop);
441
442 error = input_mt_init_slots(input, priv->chip->max_touches,
443 INPUT_MT_DIRECT);
444 if (error) {
445 dev_err(dev, "Unable to set up slots, err: %d\n", error);
446 return error;
447 }
448
449 error = devm_request_threaded_irq(dev, client->irq, NULL, ili210x_irq,
450 IRQF_ONESHOT, client->name, priv);
451 if (error) {
452 dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
453 error);
454 return error;
455 }
456
457 error = devm_add_action_or_reset(dev, ili210x_stop, priv);
458 if (error)
459 return error;
460
461 error = devm_device_add_group(dev, &ili210x_attr_group);
462 if (error) {
463 dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
464 error);
465 return error;
466 }
467
468 error = input_register_device(priv->input);
469 if (error) {
470 dev_err(dev, "Cannot register input device, err: %d\n", error);
471 return error;
472 }
473
474 return 0;
475 }
476
477 static const struct i2c_device_id ili210x_i2c_id[] = {
478 { "ili210x", (long)&ili210x_chip },
479 { "ili2117", (long)&ili211x_chip },
480 { "ili2120", (long)&ili212x_chip },
481 { "ili251x", (long)&ili251x_chip },
482 { }
483 };
484 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
485
486 static const struct of_device_id ili210x_dt_ids[] = {
487 { .compatible = "ilitek,ili210x", .data = &ili210x_chip },
488 { .compatible = "ilitek,ili2117", .data = &ili211x_chip },
489 { .compatible = "ilitek,ili2120", .data = &ili212x_chip },
490 { .compatible = "ilitek,ili251x", .data = &ili251x_chip },
491 { }
492 };
493 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
494
495 static struct i2c_driver ili210x_ts_driver = {
496 .driver = {
497 .name = "ili210x_i2c",
498 .of_match_table = ili210x_dt_ids,
499 },
500 .id_table = ili210x_i2c_id,
501 .probe = ili210x_i2c_probe,
502 };
503
504 module_i2c_driver(ili210x_ts_driver);
505
506 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
507 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
508 MODULE_LICENSE("GPL");
509