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 unsigned int *z);
34 bool (*continue_polling)(const u8 *data, bool touch);
35 unsigned int max_touches;
36 unsigned int resolution;
37 bool has_calibrate_reg;
38 bool has_pressure_reg;
39 };
40
41 struct ili210x {
42 struct i2c_client *client;
43 struct input_dev *input;
44 struct gpio_desc *reset_gpio;
45 struct touchscreen_properties prop;
46 const struct ili2xxx_chip *chip;
47 bool stop;
48 };
49
ili210x_read_reg(struct i2c_client * client,u8 reg,void * buf,size_t len)50 static int ili210x_read_reg(struct i2c_client *client,
51 u8 reg, void *buf, size_t len)
52 {
53 struct i2c_msg msg[] = {
54 {
55 .addr = client->addr,
56 .flags = 0,
57 .len = 1,
58 .buf = ®,
59 },
60 {
61 .addr = client->addr,
62 .flags = I2C_M_RD,
63 .len = len,
64 .buf = buf,
65 }
66 };
67 int error, ret;
68
69 ret = i2c_transfer(client->adapter, msg, ARRAY_SIZE(msg));
70 if (ret != ARRAY_SIZE(msg)) {
71 error = ret < 0 ? ret : -EIO;
72 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
73 return error;
74 }
75
76 return 0;
77 }
78
ili210x_read_touch_data(struct i2c_client * client,u8 * data)79 static int ili210x_read_touch_data(struct i2c_client *client, u8 *data)
80 {
81 return ili210x_read_reg(client, REG_TOUCHDATA,
82 data, ILI210X_DATA_SIZE);
83 }
84
ili210x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y,unsigned int * z)85 static bool ili210x_touchdata_to_coords(const u8 *touchdata,
86 unsigned int finger,
87 unsigned int *x, unsigned int *y,
88 unsigned int *z)
89 {
90 if (!(touchdata[0] & BIT(finger)))
91 return false;
92
93 *x = get_unaligned_be16(touchdata + 1 + (finger * 4) + 0);
94 *y = get_unaligned_be16(touchdata + 1 + (finger * 4) + 2);
95
96 return true;
97 }
98
ili210x_check_continue_polling(const u8 * data,bool touch)99 static bool ili210x_check_continue_polling(const u8 *data, bool touch)
100 {
101 return data[0] & 0xf3;
102 }
103
104 static const struct ili2xxx_chip ili210x_chip = {
105 .read_reg = ili210x_read_reg,
106 .get_touch_data = ili210x_read_touch_data,
107 .parse_touch_data = ili210x_touchdata_to_coords,
108 .continue_polling = ili210x_check_continue_polling,
109 .max_touches = 2,
110 .has_calibrate_reg = true,
111 };
112
ili211x_read_touch_data(struct i2c_client * client,u8 * data)113 static int ili211x_read_touch_data(struct i2c_client *client, u8 *data)
114 {
115 s16 sum = 0;
116 int error;
117 int ret;
118 int i;
119
120 ret = i2c_master_recv(client, data, ILI211X_DATA_SIZE);
121 if (ret != ILI211X_DATA_SIZE) {
122 error = ret < 0 ? ret : -EIO;
123 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
124 return error;
125 }
126
127 /* This chip uses custom checksum at the end of data */
128 for (i = 0; i < ILI211X_DATA_SIZE - 1; i++)
129 sum = (sum + data[i]) & 0xff;
130
131 if ((-sum & 0xff) != data[ILI211X_DATA_SIZE - 1]) {
132 dev_err(&client->dev,
133 "CRC error (crc=0x%02x expected=0x%02x)\n",
134 sum, data[ILI211X_DATA_SIZE - 1]);
135 return -EIO;
136 }
137
138 return 0;
139 }
140
ili211x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y,unsigned int * z)141 static bool ili211x_touchdata_to_coords(const u8 *touchdata,
142 unsigned int finger,
143 unsigned int *x, unsigned int *y,
144 unsigned int *z)
145 {
146 u32 data;
147
148 data = get_unaligned_be32(touchdata + 1 + (finger * 4) + 0);
149 if (data == 0xffffffff) /* Finger up */
150 return false;
151
152 *x = ((touchdata[1 + (finger * 4) + 0] & 0xf0) << 4) |
153 touchdata[1 + (finger * 4) + 1];
154 *y = ((touchdata[1 + (finger * 4) + 0] & 0x0f) << 8) |
155 touchdata[1 + (finger * 4) + 2];
156
157 return true;
158 }
159
ili211x_decline_polling(const u8 * data,bool touch)160 static bool ili211x_decline_polling(const u8 *data, bool touch)
161 {
162 return false;
163 }
164
165 static const struct ili2xxx_chip ili211x_chip = {
166 .read_reg = ili210x_read_reg,
167 .get_touch_data = ili211x_read_touch_data,
168 .parse_touch_data = ili211x_touchdata_to_coords,
169 .continue_polling = ili211x_decline_polling,
170 .max_touches = 10,
171 .resolution = 2048,
172 };
173
ili212x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y,unsigned int * z)174 static bool ili212x_touchdata_to_coords(const u8 *touchdata,
175 unsigned int finger,
176 unsigned int *x, unsigned int *y,
177 unsigned int *z)
178 {
179 u16 val;
180
181 val = get_unaligned_be16(touchdata + 3 + (finger * 5) + 0);
182 if (!(val & BIT(15))) /* Touch indication */
183 return false;
184
185 *x = val & 0x3fff;
186 *y = get_unaligned_be16(touchdata + 3 + (finger * 5) + 2);
187
188 return true;
189 }
190
ili212x_check_continue_polling(const u8 * data,bool touch)191 static bool ili212x_check_continue_polling(const u8 *data, bool touch)
192 {
193 return touch;
194 }
195
196 static const struct ili2xxx_chip ili212x_chip = {
197 .read_reg = ili210x_read_reg,
198 .get_touch_data = ili210x_read_touch_data,
199 .parse_touch_data = ili212x_touchdata_to_coords,
200 .continue_polling = ili212x_check_continue_polling,
201 .max_touches = 10,
202 .has_calibrate_reg = true,
203 };
204
ili251x_read_reg(struct i2c_client * client,u8 reg,void * buf,size_t len)205 static int ili251x_read_reg(struct i2c_client *client,
206 u8 reg, void *buf, size_t len)
207 {
208 int error;
209 int ret;
210
211 ret = i2c_master_send(client, ®, 1);
212 if (ret == 1) {
213 usleep_range(5000, 5500);
214
215 ret = i2c_master_recv(client, buf, len);
216 if (ret == len)
217 return 0;
218 }
219
220 error = ret < 0 ? ret : -EIO;
221 dev_err(&client->dev, "%s failed: %d\n", __func__, error);
222 return ret;
223 }
224
ili251x_read_touch_data(struct i2c_client * client,u8 * data)225 static int ili251x_read_touch_data(struct i2c_client *client, u8 *data)
226 {
227 int error;
228
229 error = ili251x_read_reg(client, REG_TOUCHDATA,
230 data, ILI251X_DATA_SIZE1);
231 if (!error && data[0] == 2) {
232 error = i2c_master_recv(client, data + ILI251X_DATA_SIZE1,
233 ILI251X_DATA_SIZE2);
234 if (error >= 0 && error != ILI251X_DATA_SIZE2)
235 error = -EIO;
236 }
237
238 return error;
239 }
240
ili251x_touchdata_to_coords(const u8 * touchdata,unsigned int finger,unsigned int * x,unsigned int * y,unsigned int * z)241 static bool ili251x_touchdata_to_coords(const u8 *touchdata,
242 unsigned int finger,
243 unsigned int *x, unsigned int *y,
244 unsigned int *z)
245 {
246 u16 val;
247
248 val = get_unaligned_be16(touchdata + 1 + (finger * 5) + 0);
249 if (!(val & BIT(15))) /* Touch indication */
250 return false;
251
252 *x = val & 0x3fff;
253 *y = get_unaligned_be16(touchdata + 1 + (finger * 5) + 2);
254 *z = touchdata[1 + (finger * 5) + 4];
255
256 return true;
257 }
258
ili251x_check_continue_polling(const u8 * data,bool touch)259 static bool ili251x_check_continue_polling(const u8 *data, bool touch)
260 {
261 return touch;
262 }
263
264 static const struct ili2xxx_chip ili251x_chip = {
265 .read_reg = ili251x_read_reg,
266 .get_touch_data = ili251x_read_touch_data,
267 .parse_touch_data = ili251x_touchdata_to_coords,
268 .continue_polling = ili251x_check_continue_polling,
269 .max_touches = 10,
270 .has_calibrate_reg = true,
271 .has_pressure_reg = true,
272 };
273
ili210x_report_events(struct ili210x * priv,u8 * touchdata)274 static bool ili210x_report_events(struct ili210x *priv, u8 *touchdata)
275 {
276 struct input_dev *input = priv->input;
277 int i;
278 bool contact = false, touch;
279 unsigned int x = 0, y = 0, z = 0;
280
281 for (i = 0; i < priv->chip->max_touches; i++) {
282 touch = priv->chip->parse_touch_data(touchdata, i, &x, &y, &z);
283
284 input_mt_slot(input, i);
285 if (input_mt_report_slot_state(input, MT_TOOL_FINGER, touch)) {
286 touchscreen_report_pos(input, &priv->prop, x, y, true);
287 if (priv->chip->has_pressure_reg)
288 input_report_abs(input, ABS_MT_PRESSURE, z);
289 contact = true;
290 }
291 }
292
293 input_mt_report_pointer_emulation(input, false);
294 input_sync(input);
295
296 return contact;
297 }
298
ili210x_irq(int irq,void * irq_data)299 static irqreturn_t ili210x_irq(int irq, void *irq_data)
300 {
301 struct ili210x *priv = irq_data;
302 struct i2c_client *client = priv->client;
303 const struct ili2xxx_chip *chip = priv->chip;
304 u8 touchdata[ILI210X_DATA_SIZE] = { 0 };
305 bool keep_polling;
306 bool touch;
307 int error;
308
309 do {
310 error = chip->get_touch_data(client, touchdata);
311 if (error) {
312 dev_err(&client->dev,
313 "Unable to get touch data: %d\n", error);
314 break;
315 }
316
317 touch = ili210x_report_events(priv, touchdata);
318 keep_polling = chip->continue_polling(touchdata, touch);
319 if (keep_polling)
320 msleep(ILI2XXX_POLL_PERIOD);
321 } while (!priv->stop && keep_polling);
322
323 return IRQ_HANDLED;
324 }
325
ili210x_calibrate(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)326 static ssize_t ili210x_calibrate(struct device *dev,
327 struct device_attribute *attr,
328 const char *buf, size_t count)
329 {
330 struct i2c_client *client = to_i2c_client(dev);
331 struct ili210x *priv = i2c_get_clientdata(client);
332 unsigned long calibrate;
333 int rc;
334 u8 cmd = REG_CALIBRATE;
335
336 if (kstrtoul(buf, 10, &calibrate))
337 return -EINVAL;
338
339 if (calibrate > 1)
340 return -EINVAL;
341
342 if (calibrate) {
343 rc = i2c_master_send(priv->client, &cmd, sizeof(cmd));
344 if (rc != sizeof(cmd))
345 return -EIO;
346 }
347
348 return count;
349 }
350 static DEVICE_ATTR(calibrate, S_IWUSR, NULL, ili210x_calibrate);
351
352 static struct attribute *ili210x_attributes[] = {
353 &dev_attr_calibrate.attr,
354 NULL,
355 };
356
ili210x_calibrate_visible(struct kobject * kobj,struct attribute * attr,int index)357 static umode_t ili210x_calibrate_visible(struct kobject *kobj,
358 struct attribute *attr, int index)
359 {
360 struct device *dev = kobj_to_dev(kobj);
361 struct i2c_client *client = to_i2c_client(dev);
362 struct ili210x *priv = i2c_get_clientdata(client);
363
364 return priv->chip->has_calibrate_reg ? attr->mode : 0;
365 }
366
367 static const struct attribute_group ili210x_attr_group = {
368 .attrs = ili210x_attributes,
369 .is_visible = ili210x_calibrate_visible,
370 };
371
ili210x_power_down(void * data)372 static void ili210x_power_down(void *data)
373 {
374 struct gpio_desc *reset_gpio = data;
375
376 gpiod_set_value_cansleep(reset_gpio, 1);
377 }
378
ili210x_stop(void * data)379 static void ili210x_stop(void *data)
380 {
381 struct ili210x *priv = data;
382
383 /* Tell ISR to quit even if there is a contact. */
384 priv->stop = true;
385 }
386
ili210x_i2c_probe(struct i2c_client * client,const struct i2c_device_id * id)387 static int ili210x_i2c_probe(struct i2c_client *client,
388 const struct i2c_device_id *id)
389 {
390 struct device *dev = &client->dev;
391 const struct ili2xxx_chip *chip;
392 struct ili210x *priv;
393 struct gpio_desc *reset_gpio;
394 struct input_dev *input;
395 int error;
396 unsigned int max_xy;
397
398 dev_dbg(dev, "Probing for ILI210X I2C Touschreen driver");
399
400 chip = device_get_match_data(dev);
401 if (!chip && id)
402 chip = (const struct ili2xxx_chip *)id->driver_data;
403 if (!chip) {
404 dev_err(&client->dev, "unknown device model\n");
405 return -ENODEV;
406 }
407
408 if (client->irq <= 0) {
409 dev_err(dev, "No IRQ!\n");
410 return -EINVAL;
411 }
412
413 reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
414 if (IS_ERR(reset_gpio))
415 return PTR_ERR(reset_gpio);
416
417 if (reset_gpio) {
418 error = devm_add_action_or_reset(dev, ili210x_power_down,
419 reset_gpio);
420 if (error)
421 return error;
422
423 usleep_range(12000, 15000);
424 gpiod_set_value_cansleep(reset_gpio, 0);
425 msleep(160);
426 }
427
428 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
429 if (!priv)
430 return -ENOMEM;
431
432 input = devm_input_allocate_device(dev);
433 if (!input)
434 return -ENOMEM;
435
436 priv->client = client;
437 priv->input = input;
438 priv->reset_gpio = reset_gpio;
439 priv->chip = chip;
440 i2c_set_clientdata(client, priv);
441
442 /* Setup input device */
443 input->name = "ILI210x Touchscreen";
444 input->id.bustype = BUS_I2C;
445
446 /* Multi touch */
447 max_xy = (chip->resolution ?: SZ_64K) - 1;
448 input_set_abs_params(input, ABS_MT_POSITION_X, 0, max_xy, 0, 0);
449 input_set_abs_params(input, ABS_MT_POSITION_Y, 0, max_xy, 0, 0);
450 if (priv->chip->has_pressure_reg)
451 input_set_abs_params(input, ABS_MT_PRESSURE, 0, 0xa, 0, 0);
452 touchscreen_parse_properties(input, true, &priv->prop);
453
454 error = input_mt_init_slots(input, priv->chip->max_touches,
455 INPUT_MT_DIRECT);
456 if (error) {
457 dev_err(dev, "Unable to set up slots, err: %d\n", error);
458 return error;
459 }
460
461 error = devm_request_threaded_irq(dev, client->irq, NULL, ili210x_irq,
462 IRQF_ONESHOT, client->name, priv);
463 if (error) {
464 dev_err(dev, "Unable to request touchscreen IRQ, err: %d\n",
465 error);
466 return error;
467 }
468
469 error = devm_add_action_or_reset(dev, ili210x_stop, priv);
470 if (error)
471 return error;
472
473 error = devm_device_add_group(dev, &ili210x_attr_group);
474 if (error) {
475 dev_err(dev, "Unable to create sysfs attributes, err: %d\n",
476 error);
477 return error;
478 }
479
480 error = input_register_device(priv->input);
481 if (error) {
482 dev_err(dev, "Cannot register input device, err: %d\n", error);
483 return error;
484 }
485
486 return 0;
487 }
488
489 static const struct i2c_device_id ili210x_i2c_id[] = {
490 { "ili210x", (long)&ili210x_chip },
491 { "ili2117", (long)&ili211x_chip },
492 { "ili2120", (long)&ili212x_chip },
493 { "ili251x", (long)&ili251x_chip },
494 { }
495 };
496 MODULE_DEVICE_TABLE(i2c, ili210x_i2c_id);
497
498 static const struct of_device_id ili210x_dt_ids[] = {
499 { .compatible = "ilitek,ili210x", .data = &ili210x_chip },
500 { .compatible = "ilitek,ili2117", .data = &ili211x_chip },
501 { .compatible = "ilitek,ili2120", .data = &ili212x_chip },
502 { .compatible = "ilitek,ili251x", .data = &ili251x_chip },
503 { }
504 };
505 MODULE_DEVICE_TABLE(of, ili210x_dt_ids);
506
507 static struct i2c_driver ili210x_ts_driver = {
508 .driver = {
509 .name = "ili210x_i2c",
510 .of_match_table = ili210x_dt_ids,
511 },
512 .id_table = ili210x_i2c_id,
513 .probe = ili210x_i2c_probe,
514 };
515
516 module_i2c_driver(ili210x_ts_driver);
517
518 MODULE_AUTHOR("Olivier Sobrie <olivier@sobrie.be>");
519 MODULE_DESCRIPTION("ILI210X I2C Touchscreen Driver");
520 MODULE_LICENSE("GPL");
521