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