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