1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -------------------------------------------------------------------------
3  * Copyright (C) 2014-2015, Intel Corporation
4  *
5  * Derived from:
6  *  gslX68X.c
7  *  Copyright (C) 2010-2015, Shanghai Sileadinc Co.Ltd
8  *
9  * -------------------------------------------------------------------------
10  */
11 
12 #include <linux/i2c.h>
13 #include <linux/module.h>
14 #include <linux/acpi.h>
15 #include <linux/interrupt.h>
16 #include <linux/gpio/consumer.h>
17 #include <linux/delay.h>
18 #include <linux/firmware.h>
19 #include <linux/input.h>
20 #include <linux/input/mt.h>
21 #include <linux/input/touchscreen.h>
22 #include <linux/pm.h>
23 #include <linux/irq.h>
24 #include <linux/regulator/consumer.h>
25 
26 #include <asm/unaligned.h>
27 
28 #define SILEAD_TS_NAME		"silead_ts"
29 
30 #define SILEAD_REG_RESET	0xE0
31 #define SILEAD_REG_DATA		0x80
32 #define SILEAD_REG_TOUCH_NR	0x80
33 #define SILEAD_REG_POWER	0xBC
34 #define SILEAD_REG_CLOCK	0xE4
35 #define SILEAD_REG_STATUS	0xB0
36 #define SILEAD_REG_ID		0xFC
37 #define SILEAD_REG_MEM_CHECK	0xB0
38 
39 #define SILEAD_STATUS_OK	0x5A5A5A5A
40 #define SILEAD_TS_DATA_LEN	44
41 #define SILEAD_CLOCK		0x04
42 
43 #define SILEAD_CMD_RESET	0x88
44 #define SILEAD_CMD_START	0x00
45 
46 #define SILEAD_POINT_DATA_LEN	0x04
47 #define SILEAD_POINT_Y_OFF      0x00
48 #define SILEAD_POINT_Y_MSB_OFF	0x01
49 #define SILEAD_POINT_X_OFF	0x02
50 #define SILEAD_POINT_X_MSB_OFF	0x03
51 #define SILEAD_EXTRA_DATA_MASK	0xF0
52 
53 #define SILEAD_CMD_SLEEP_MIN	10000
54 #define SILEAD_CMD_SLEEP_MAX	20000
55 #define SILEAD_POWER_SLEEP	20
56 #define SILEAD_STARTUP_SLEEP	30
57 
58 #define SILEAD_MAX_FINGERS	10
59 
60 enum silead_ts_power {
61 	SILEAD_POWER_ON  = 1,
62 	SILEAD_POWER_OFF = 0
63 };
64 
65 struct silead_ts_data {
66 	struct i2c_client *client;
67 	struct gpio_desc *gpio_power;
68 	struct input_dev *input;
69 	struct regulator_bulk_data regulators[2];
70 	char fw_name[64];
71 	struct touchscreen_properties prop;
72 	u32 max_fingers;
73 	u32 chip_id;
74 	struct input_mt_pos pos[SILEAD_MAX_FINGERS];
75 	int slots[SILEAD_MAX_FINGERS];
76 	int id[SILEAD_MAX_FINGERS];
77 };
78 
79 struct silead_fw_data {
80 	u32 offset;
81 	u32 val;
82 };
83 
84 static int silead_ts_request_input_dev(struct silead_ts_data *data)
85 {
86 	struct device *dev = &data->client->dev;
87 	int error;
88 
89 	data->input = devm_input_allocate_device(dev);
90 	if (!data->input) {
91 		dev_err(dev,
92 			"Failed to allocate input device\n");
93 		return -ENOMEM;
94 	}
95 
96 	input_set_abs_params(data->input, ABS_MT_POSITION_X, 0, 4095, 0, 0);
97 	input_set_abs_params(data->input, ABS_MT_POSITION_Y, 0, 4095, 0, 0);
98 	touchscreen_parse_properties(data->input, true, &data->prop);
99 
100 	input_mt_init_slots(data->input, data->max_fingers,
101 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED |
102 			    INPUT_MT_TRACK);
103 
104 	if (device_property_read_bool(dev, "silead,home-button"))
105 		input_set_capability(data->input, EV_KEY, KEY_LEFTMETA);
106 
107 	data->input->name = SILEAD_TS_NAME;
108 	data->input->phys = "input/ts";
109 	data->input->id.bustype = BUS_I2C;
110 
111 	error = input_register_device(data->input);
112 	if (error) {
113 		dev_err(dev, "Failed to register input device: %d\n", error);
114 		return error;
115 	}
116 
117 	return 0;
118 }
119 
120 static void silead_ts_set_power(struct i2c_client *client,
121 				enum silead_ts_power state)
122 {
123 	struct silead_ts_data *data = i2c_get_clientdata(client);
124 
125 	if (data->gpio_power) {
126 		gpiod_set_value_cansleep(data->gpio_power, state);
127 		msleep(SILEAD_POWER_SLEEP);
128 	}
129 }
130 
131 static void silead_ts_read_data(struct i2c_client *client)
132 {
133 	struct silead_ts_data *data = i2c_get_clientdata(client);
134 	struct input_dev *input = data->input;
135 	struct device *dev = &client->dev;
136 	u8 *bufp, buf[SILEAD_TS_DATA_LEN];
137 	int touch_nr, softbutton, error, i;
138 	bool softbutton_pressed = false;
139 
140 	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_DATA,
141 					      SILEAD_TS_DATA_LEN, buf);
142 	if (error < 0) {
143 		dev_err(dev, "Data read error %d\n", error);
144 		return;
145 	}
146 
147 	if (buf[0] > data->max_fingers) {
148 		dev_warn(dev, "More touches reported then supported %d > %d\n",
149 			 buf[0], data->max_fingers);
150 		buf[0] = data->max_fingers;
151 	}
152 
153 	touch_nr = 0;
154 	bufp = buf + SILEAD_POINT_DATA_LEN;
155 	for (i = 0; i < buf[0]; i++, bufp += SILEAD_POINT_DATA_LEN) {
156 		softbutton = (bufp[SILEAD_POINT_Y_MSB_OFF] &
157 			      SILEAD_EXTRA_DATA_MASK) >> 4;
158 
159 		if (softbutton) {
160 			/*
161 			 * For now only respond to softbutton == 0x01, some
162 			 * tablets *without* a capacative button send 0x04
163 			 * when crossing the edges of the screen.
164 			 */
165 			if (softbutton == 0x01)
166 				softbutton_pressed = true;
167 
168 			continue;
169 		}
170 
171 		/*
172 		 * Bits 4-7 are the touch id, note not all models have
173 		 * hardware touch ids so atm we don't use these.
174 		 */
175 		data->id[touch_nr] = (bufp[SILEAD_POINT_X_MSB_OFF] &
176 				      SILEAD_EXTRA_DATA_MASK) >> 4;
177 		touchscreen_set_mt_pos(&data->pos[touch_nr], &data->prop,
178 			get_unaligned_le16(&bufp[SILEAD_POINT_X_OFF]) & 0xfff,
179 			get_unaligned_le16(&bufp[SILEAD_POINT_Y_OFF]) & 0xfff);
180 		touch_nr++;
181 	}
182 
183 	input_mt_assign_slots(input, data->slots, data->pos, touch_nr, 0);
184 
185 	for (i = 0; i < touch_nr; i++) {
186 		input_mt_slot(input, data->slots[i]);
187 		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
188 		input_report_abs(input, ABS_MT_POSITION_X, data->pos[i].x);
189 		input_report_abs(input, ABS_MT_POSITION_Y, data->pos[i].y);
190 
191 		dev_dbg(dev, "x=%d y=%d hw_id=%d sw_id=%d\n", data->pos[i].x,
192 			data->pos[i].y, data->id[i], data->slots[i]);
193 	}
194 
195 	input_mt_sync_frame(input);
196 	input_report_key(input, KEY_LEFTMETA, softbutton_pressed);
197 	input_sync(input);
198 }
199 
200 static int silead_ts_init(struct i2c_client *client)
201 {
202 	struct silead_ts_data *data = i2c_get_clientdata(client);
203 	int error;
204 
205 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
206 					  SILEAD_CMD_RESET);
207 	if (error)
208 		goto i2c_write_err;
209 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
210 
211 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_TOUCH_NR,
212 					data->max_fingers);
213 	if (error)
214 		goto i2c_write_err;
215 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
216 
217 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
218 					  SILEAD_CLOCK);
219 	if (error)
220 		goto i2c_write_err;
221 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
222 
223 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
224 					  SILEAD_CMD_START);
225 	if (error)
226 		goto i2c_write_err;
227 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
228 
229 	return 0;
230 
231 i2c_write_err:
232 	dev_err(&client->dev, "Registers clear error %d\n", error);
233 	return error;
234 }
235 
236 static int silead_ts_reset(struct i2c_client *client)
237 {
238 	int error;
239 
240 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET,
241 					  SILEAD_CMD_RESET);
242 	if (error)
243 		goto i2c_write_err;
244 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
245 
246 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_CLOCK,
247 					  SILEAD_CLOCK);
248 	if (error)
249 		goto i2c_write_err;
250 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
251 
252 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_POWER,
253 					  SILEAD_CMD_START);
254 	if (error)
255 		goto i2c_write_err;
256 	usleep_range(SILEAD_CMD_SLEEP_MIN, SILEAD_CMD_SLEEP_MAX);
257 
258 	return 0;
259 
260 i2c_write_err:
261 	dev_err(&client->dev, "Chip reset error %d\n", error);
262 	return error;
263 }
264 
265 static int silead_ts_startup(struct i2c_client *client)
266 {
267 	int error;
268 
269 	error = i2c_smbus_write_byte_data(client, SILEAD_REG_RESET, 0x00);
270 	if (error) {
271 		dev_err(&client->dev, "Startup error %d\n", error);
272 		return error;
273 	}
274 
275 	msleep(SILEAD_STARTUP_SLEEP);
276 
277 	return 0;
278 }
279 
280 static int silead_ts_load_fw(struct i2c_client *client)
281 {
282 	struct device *dev = &client->dev;
283 	struct silead_ts_data *data = i2c_get_clientdata(client);
284 	unsigned int fw_size, i;
285 	const struct firmware *fw;
286 	struct silead_fw_data *fw_data;
287 	int error;
288 
289 	dev_dbg(dev, "Firmware file name: %s", data->fw_name);
290 
291 	error = request_firmware(&fw, data->fw_name, dev);
292 	if (error) {
293 		dev_err(dev, "Firmware request error %d\n", error);
294 		return error;
295 	}
296 
297 	fw_size = fw->size / sizeof(*fw_data);
298 	fw_data = (struct silead_fw_data *)fw->data;
299 
300 	for (i = 0; i < fw_size; i++) {
301 		error = i2c_smbus_write_i2c_block_data(client,
302 						       fw_data[i].offset,
303 						       4,
304 						       (u8 *)&fw_data[i].val);
305 		if (error) {
306 			dev_err(dev, "Firmware load error %d\n", error);
307 			break;
308 		}
309 	}
310 
311 	release_firmware(fw);
312 	return error ?: 0;
313 }
314 
315 static u32 silead_ts_get_status(struct i2c_client *client)
316 {
317 	int error;
318 	__le32 status;
319 
320 	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_STATUS,
321 					      sizeof(status), (u8 *)&status);
322 	if (error < 0) {
323 		dev_err(&client->dev, "Status read error %d\n", error);
324 		return error;
325 	}
326 
327 	return le32_to_cpu(status);
328 }
329 
330 static int silead_ts_get_id(struct i2c_client *client)
331 {
332 	struct silead_ts_data *data = i2c_get_clientdata(client);
333 	__le32 chip_id;
334 	int error;
335 
336 	error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
337 					      sizeof(chip_id), (u8 *)&chip_id);
338 	if (error < 0) {
339 		dev_err(&client->dev, "Chip ID read error %d\n", error);
340 		return error;
341 	}
342 
343 	data->chip_id = le32_to_cpu(chip_id);
344 	dev_info(&client->dev, "Silead chip ID: 0x%8X", data->chip_id);
345 
346 	return 0;
347 }
348 
349 static int silead_ts_setup(struct i2c_client *client)
350 {
351 	int error;
352 	u32 status;
353 
354 	silead_ts_set_power(client, SILEAD_POWER_OFF);
355 	silead_ts_set_power(client, SILEAD_POWER_ON);
356 
357 	error = silead_ts_get_id(client);
358 	if (error)
359 		return error;
360 
361 	error = silead_ts_init(client);
362 	if (error)
363 		return error;
364 
365 	error = silead_ts_reset(client);
366 	if (error)
367 		return error;
368 
369 	error = silead_ts_load_fw(client);
370 	if (error)
371 		return error;
372 
373 	error = silead_ts_startup(client);
374 	if (error)
375 		return error;
376 
377 	status = silead_ts_get_status(client);
378 	if (status != SILEAD_STATUS_OK) {
379 		dev_err(&client->dev,
380 			"Initialization error, status: 0x%X\n", status);
381 		return -ENODEV;
382 	}
383 
384 	return 0;
385 }
386 
387 static irqreturn_t silead_ts_threaded_irq_handler(int irq, void *id)
388 {
389 	struct silead_ts_data *data = id;
390 	struct i2c_client *client = data->client;
391 
392 	silead_ts_read_data(client);
393 
394 	return IRQ_HANDLED;
395 }
396 
397 static void silead_ts_read_props(struct i2c_client *client)
398 {
399 	struct silead_ts_data *data = i2c_get_clientdata(client);
400 	struct device *dev = &client->dev;
401 	const char *str;
402 	int error;
403 
404 	error = device_property_read_u32(dev, "silead,max-fingers",
405 					 &data->max_fingers);
406 	if (error) {
407 		dev_dbg(dev, "Max fingers read error %d\n", error);
408 		data->max_fingers = 5; /* Most devices handle up-to 5 fingers */
409 	}
410 
411 	error = device_property_read_string(dev, "firmware-name", &str);
412 	if (!error)
413 		snprintf(data->fw_name, sizeof(data->fw_name),
414 			 "silead/%s", str);
415 	else
416 		dev_dbg(dev, "Firmware file name read error. Using default.");
417 }
418 
419 #ifdef CONFIG_ACPI
420 static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
421 					 const struct i2c_device_id *id)
422 {
423 	const struct acpi_device_id *acpi_id;
424 	struct device *dev = &data->client->dev;
425 	int i;
426 
427 	if (ACPI_HANDLE(dev)) {
428 		acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
429 		if (!acpi_id)
430 			return -ENODEV;
431 
432 		snprintf(data->fw_name, sizeof(data->fw_name),
433 			 "silead/%s.fw", acpi_id->id);
434 
435 		for (i = 0; i < strlen(data->fw_name); i++)
436 			data->fw_name[i] = tolower(data->fw_name[i]);
437 	} else {
438 		snprintf(data->fw_name, sizeof(data->fw_name),
439 			 "silead/%s.fw", id->name);
440 	}
441 
442 	return 0;
443 }
444 #else
445 static int silead_ts_set_default_fw_name(struct silead_ts_data *data,
446 					 const struct i2c_device_id *id)
447 {
448 	snprintf(data->fw_name, sizeof(data->fw_name),
449 		 "silead/%s.fw", id->name);
450 	return 0;
451 }
452 #endif
453 
454 static void silead_disable_regulator(void *arg)
455 {
456 	struct silead_ts_data *data = arg;
457 
458 	regulator_bulk_disable(ARRAY_SIZE(data->regulators), data->regulators);
459 }
460 
461 static int silead_ts_probe(struct i2c_client *client,
462 			   const struct i2c_device_id *id)
463 {
464 	struct silead_ts_data *data;
465 	struct device *dev = &client->dev;
466 	int error;
467 
468 	if (!i2c_check_functionality(client->adapter,
469 				     I2C_FUNC_I2C |
470 				     I2C_FUNC_SMBUS_READ_I2C_BLOCK |
471 				     I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
472 		dev_err(dev, "I2C functionality check failed\n");
473 		return -ENXIO;
474 	}
475 
476 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
477 	if (!data)
478 		return -ENOMEM;
479 
480 	i2c_set_clientdata(client, data);
481 	data->client = client;
482 
483 	error = silead_ts_set_default_fw_name(data, id);
484 	if (error)
485 		return error;
486 
487 	silead_ts_read_props(client);
488 
489 	/* We must have the IRQ provided by DT or ACPI subsytem */
490 	if (client->irq <= 0)
491 		return -ENODEV;
492 
493 	data->regulators[0].supply = "vddio";
494 	data->regulators[1].supply = "avdd";
495 	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(data->regulators),
496 					data->regulators);
497 	if (error)
498 		return error;
499 
500 	/*
501 	 * Enable regulators at probe and disable them at remove, we need
502 	 * to keep the chip powered otherwise it forgets its firmware.
503 	 */
504 	error = regulator_bulk_enable(ARRAY_SIZE(data->regulators),
505 				      data->regulators);
506 	if (error)
507 		return error;
508 
509 	error = devm_add_action_or_reset(dev, silead_disable_regulator, data);
510 	if (error)
511 		return error;
512 
513 	/* Power GPIO pin */
514 	data->gpio_power = devm_gpiod_get_optional(dev, "power", GPIOD_OUT_LOW);
515 	if (IS_ERR(data->gpio_power)) {
516 		if (PTR_ERR(data->gpio_power) != -EPROBE_DEFER)
517 			dev_err(dev, "Shutdown GPIO request failed\n");
518 		return PTR_ERR(data->gpio_power);
519 	}
520 
521 	error = silead_ts_setup(client);
522 	if (error)
523 		return error;
524 
525 	error = silead_ts_request_input_dev(data);
526 	if (error)
527 		return error;
528 
529 	error = devm_request_threaded_irq(dev, client->irq,
530 					  NULL, silead_ts_threaded_irq_handler,
531 					  IRQF_ONESHOT, client->name, data);
532 	if (error) {
533 		if (error != -EPROBE_DEFER)
534 			dev_err(dev, "IRQ request failed %d\n", error);
535 		return error;
536 	}
537 
538 	return 0;
539 }
540 
541 static int __maybe_unused silead_ts_suspend(struct device *dev)
542 {
543 	struct i2c_client *client = to_i2c_client(dev);
544 
545 	disable_irq(client->irq);
546 	silead_ts_set_power(client, SILEAD_POWER_OFF);
547 	return 0;
548 }
549 
550 static int __maybe_unused silead_ts_resume(struct device *dev)
551 {
552 	struct i2c_client *client = to_i2c_client(dev);
553 	bool second_try = false;
554 	int error, status;
555 
556 	silead_ts_set_power(client, SILEAD_POWER_ON);
557 
558  retry:
559 	error = silead_ts_reset(client);
560 	if (error)
561 		return error;
562 
563 	if (second_try) {
564 		error = silead_ts_load_fw(client);
565 		if (error)
566 			return error;
567 	}
568 
569 	error = silead_ts_startup(client);
570 	if (error)
571 		return error;
572 
573 	status = silead_ts_get_status(client);
574 	if (status != SILEAD_STATUS_OK) {
575 		if (!second_try) {
576 			second_try = true;
577 			dev_dbg(dev, "Reloading firmware after unsuccessful resume\n");
578 			goto retry;
579 		}
580 		dev_err(dev, "Resume error, status: 0x%02x\n", status);
581 		return -ENODEV;
582 	}
583 
584 	enable_irq(client->irq);
585 
586 	return 0;
587 }
588 
589 static SIMPLE_DEV_PM_OPS(silead_ts_pm, silead_ts_suspend, silead_ts_resume);
590 
591 static const struct i2c_device_id silead_ts_id[] = {
592 	{ "gsl1680", 0 },
593 	{ "gsl1688", 0 },
594 	{ "gsl3670", 0 },
595 	{ "gsl3675", 0 },
596 	{ "gsl3692", 0 },
597 	{ "mssl1680", 0 },
598 	{ }
599 };
600 MODULE_DEVICE_TABLE(i2c, silead_ts_id);
601 
602 #ifdef CONFIG_ACPI
603 static const struct acpi_device_id silead_ts_acpi_match[] = {
604 	{ "GSL1680", 0 },
605 	{ "GSL1688", 0 },
606 	{ "GSL3670", 0 },
607 	{ "GSL3675", 0 },
608 	{ "GSL3692", 0 },
609 	{ "MSSL1680", 0 },
610 	{ "MSSL0001", 0 },
611 	{ "MSSL0002", 0 },
612 	{ "MSSL0017", 0 },
613 	{ }
614 };
615 MODULE_DEVICE_TABLE(acpi, silead_ts_acpi_match);
616 #endif
617 
618 #ifdef CONFIG_OF
619 static const struct of_device_id silead_ts_of_match[] = {
620 	{ .compatible = "silead,gsl1680" },
621 	{ .compatible = "silead,gsl1688" },
622 	{ .compatible = "silead,gsl3670" },
623 	{ .compatible = "silead,gsl3675" },
624 	{ .compatible = "silead,gsl3692" },
625 	{ },
626 };
627 MODULE_DEVICE_TABLE(of, silead_ts_of_match);
628 #endif
629 
630 static struct i2c_driver silead_ts_driver = {
631 	.probe = silead_ts_probe,
632 	.id_table = silead_ts_id,
633 	.driver = {
634 		.name = SILEAD_TS_NAME,
635 		.acpi_match_table = ACPI_PTR(silead_ts_acpi_match),
636 		.of_match_table = of_match_ptr(silead_ts_of_match),
637 		.pm = &silead_ts_pm,
638 	},
639 };
640 module_i2c_driver(silead_ts_driver);
641 
642 MODULE_AUTHOR("Robert Dolca <robert.dolca@intel.com>");
643 MODULE_DESCRIPTION("Silead I2C touchscreen driver");
644 MODULE_LICENSE("GPL");
645