1 /*
2  *  Driver for Goodix Touchscreens
3  *
4  *  Copyright (c) 2014 Red Hat Inc.
5  *
6  *  This code is based on gt9xx.c authored by andrew@goodix.com:
7  *
8  *  2010 - 2012 Goodix Technology.
9  */
10 
11 /*
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU General Public License as published by the Free
14  * Software Foundation; version 2 of the License.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/dmi.h>
19 #include <linux/i2c.h>
20 #include <linux/input.h>
21 #include <linux/input/mt.h>
22 #include <linux/module.h>
23 #include <linux/delay.h>
24 #include <linux/irq.h>
25 #include <linux/interrupt.h>
26 #include <linux/slab.h>
27 #include <linux/acpi.h>
28 #include <linux/of.h>
29 #include <asm/unaligned.h>
30 
31 struct goodix_ts_data {
32 	struct i2c_client *client;
33 	struct input_dev *input_dev;
34 	int abs_x_max;
35 	int abs_y_max;
36 	unsigned int max_touch_num;
37 	unsigned int int_trigger_type;
38 	bool rotated_screen;
39 };
40 
41 #define GOODIX_MAX_HEIGHT		4096
42 #define GOODIX_MAX_WIDTH		4096
43 #define GOODIX_INT_TRIGGER		1
44 #define GOODIX_CONTACT_SIZE		8
45 #define GOODIX_MAX_CONTACTS		10
46 
47 #define GOODIX_CONFIG_MAX_LENGTH	240
48 
49 /* Register defines */
50 #define GOODIX_READ_COOR_ADDR		0x814E
51 #define GOODIX_REG_CONFIG_DATA		0x8047
52 #define GOODIX_REG_ID			0x8140
53 
54 #define RESOLUTION_LOC		1
55 #define MAX_CONTACTS_LOC	5
56 #define TRIGGER_LOC		6
57 
58 static const unsigned long goodix_irq_flags[] = {
59 	IRQ_TYPE_EDGE_RISING,
60 	IRQ_TYPE_EDGE_FALLING,
61 	IRQ_TYPE_LEVEL_LOW,
62 	IRQ_TYPE_LEVEL_HIGH,
63 };
64 
65 /*
66  * Those tablets have their coordinates origin at the bottom right
67  * of the tablet, as if rotated 180 degrees
68  */
69 static const struct dmi_system_id rotated_screen[] = {
70 #if defined(CONFIG_DMI) && defined(CONFIG_X86)
71 	{
72 		.ident = "WinBook TW100",
73 		.matches = {
74 			DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
75 			DMI_MATCH(DMI_PRODUCT_NAME, "TW100")
76 		}
77 	},
78 	{
79 		.ident = "WinBook TW700",
80 		.matches = {
81 			DMI_MATCH(DMI_SYS_VENDOR, "WinBook"),
82 			DMI_MATCH(DMI_PRODUCT_NAME, "TW700")
83 		},
84 	},
85 #endif
86 	{}
87 };
88 
89 /**
90  * goodix_i2c_read - read data from a register of the i2c slave device.
91  *
92  * @client: i2c device.
93  * @reg: the register to read from.
94  * @buf: raw write data buffer.
95  * @len: length of the buffer to write
96  */
97 static int goodix_i2c_read(struct i2c_client *client,
98 			   u16 reg, u8 *buf, int len)
99 {
100 	struct i2c_msg msgs[2];
101 	u16 wbuf = cpu_to_be16(reg);
102 	int ret;
103 
104 	msgs[0].flags = 0;
105 	msgs[0].addr  = client->addr;
106 	msgs[0].len   = 2;
107 	msgs[0].buf   = (u8 *)&wbuf;
108 
109 	msgs[1].flags = I2C_M_RD;
110 	msgs[1].addr  = client->addr;
111 	msgs[1].len   = len;
112 	msgs[1].buf   = buf;
113 
114 	ret = i2c_transfer(client->adapter, msgs, 2);
115 	return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
116 }
117 
118 static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
119 {
120 	int touch_num;
121 	int error;
122 
123 	error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR, data,
124 				GOODIX_CONTACT_SIZE + 1);
125 	if (error) {
126 		dev_err(&ts->client->dev, "I2C transfer error: %d\n", error);
127 		return error;
128 	}
129 
130 	if (!(data[0] & 0x80))
131 		return -EAGAIN;
132 
133 	touch_num = data[0] & 0x0f;
134 	if (touch_num > ts->max_touch_num)
135 		return -EPROTO;
136 
137 	if (touch_num > 1) {
138 		data += 1 + GOODIX_CONTACT_SIZE;
139 		error = goodix_i2c_read(ts->client,
140 					GOODIX_READ_COOR_ADDR +
141 						1 + GOODIX_CONTACT_SIZE,
142 					data,
143 					GOODIX_CONTACT_SIZE * (touch_num - 1));
144 		if (error)
145 			return error;
146 	}
147 
148 	return touch_num;
149 }
150 
151 static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
152 {
153 	int id = coor_data[0] & 0x0F;
154 	int input_x = get_unaligned_le16(&coor_data[1]);
155 	int input_y = get_unaligned_le16(&coor_data[3]);
156 	int input_w = get_unaligned_le16(&coor_data[5]);
157 
158 	if (ts->rotated_screen) {
159 		input_x = ts->abs_x_max - input_x;
160 		input_y = ts->abs_y_max - input_y;
161 	}
162 
163 	input_mt_slot(ts->input_dev, id);
164 	input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
165 	input_report_abs(ts->input_dev, ABS_MT_POSITION_X, input_x);
166 	input_report_abs(ts->input_dev, ABS_MT_POSITION_Y, input_y);
167 	input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, input_w);
168 	input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
169 }
170 
171 /**
172  * goodix_process_events - Process incoming events
173  *
174  * @ts: our goodix_ts_data pointer
175  *
176  * Called when the IRQ is triggered. Read the current device state, and push
177  * the input events to the user space.
178  */
179 static void goodix_process_events(struct goodix_ts_data *ts)
180 {
181 	u8  point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
182 	int touch_num;
183 	int i;
184 
185 	touch_num = goodix_ts_read_input_report(ts, point_data);
186 	if (touch_num < 0)
187 		return;
188 
189 	for (i = 0; i < touch_num; i++)
190 		goodix_ts_report_touch(ts,
191 				&point_data[1 + GOODIX_CONTACT_SIZE * i]);
192 
193 	input_mt_sync_frame(ts->input_dev);
194 	input_sync(ts->input_dev);
195 }
196 
197 /**
198  * goodix_ts_irq_handler - The IRQ handler
199  *
200  * @irq: interrupt number.
201  * @dev_id: private data pointer.
202  */
203 static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
204 {
205 	static const u8 end_cmd[] = {
206 		GOODIX_READ_COOR_ADDR >> 8,
207 		GOODIX_READ_COOR_ADDR & 0xff,
208 		0
209 	};
210 	struct goodix_ts_data *ts = dev_id;
211 
212 	goodix_process_events(ts);
213 
214 	if (i2c_master_send(ts->client, end_cmd, sizeof(end_cmd)) < 0)
215 		dev_err(&ts->client->dev, "I2C write end_cmd error\n");
216 
217 	return IRQ_HANDLED;
218 }
219 
220 /**
221  * goodix_read_config - Read the embedded configuration of the panel
222  *
223  * @ts: our goodix_ts_data pointer
224  *
225  * Must be called during probe
226  */
227 static void goodix_read_config(struct goodix_ts_data *ts)
228 {
229 	u8 config[GOODIX_CONFIG_MAX_LENGTH];
230 	int error;
231 
232 	error = goodix_i2c_read(ts->client, GOODIX_REG_CONFIG_DATA,
233 				config,
234 				GOODIX_CONFIG_MAX_LENGTH);
235 	if (error) {
236 		dev_warn(&ts->client->dev,
237 			 "Error reading config (%d), using defaults\n",
238 			 error);
239 		ts->abs_x_max = GOODIX_MAX_WIDTH;
240 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
241 		ts->int_trigger_type = GOODIX_INT_TRIGGER;
242 		ts->max_touch_num = GOODIX_MAX_CONTACTS;
243 		return;
244 	}
245 
246 	ts->abs_x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
247 	ts->abs_y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
248 	ts->int_trigger_type = config[TRIGGER_LOC] & 0x03;
249 	ts->max_touch_num = config[MAX_CONTACTS_LOC] & 0x0f;
250 	if (!ts->abs_x_max || !ts->abs_y_max || !ts->max_touch_num) {
251 		dev_err(&ts->client->dev,
252 			"Invalid config, using defaults\n");
253 		ts->abs_x_max = GOODIX_MAX_WIDTH;
254 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
255 		ts->max_touch_num = GOODIX_MAX_CONTACTS;
256 	}
257 
258 	ts->rotated_screen = dmi_check_system(rotated_screen);
259 	if (ts->rotated_screen)
260 		dev_dbg(&ts->client->dev,
261 			 "Applying '180 degrees rotated screen' quirk\n");
262 }
263 
264 /**
265  * goodix_read_version - Read goodix touchscreen version
266  *
267  * @client: the i2c client
268  * @version: output buffer containing the version on success
269  * @id: output buffer containing the id on success
270  */
271 static int goodix_read_version(struct i2c_client *client, u16 *version, u16 *id)
272 {
273 	int error;
274 	u8 buf[6];
275 	char id_str[5];
276 
277 	error = goodix_i2c_read(client, GOODIX_REG_ID, buf, sizeof(buf));
278 	if (error) {
279 		dev_err(&client->dev, "read version failed: %d\n", error);
280 		return error;
281 	}
282 
283 	memcpy(id_str, buf, 4);
284 	id_str[4] = 0;
285 	if (kstrtou16(id_str, 10, id))
286 		*id = 0x1001;
287 
288 	*version = get_unaligned_le16(&buf[4]);
289 
290 	dev_info(&client->dev, "ID %d, version: %04x\n", *id, *version);
291 
292 	return 0;
293 }
294 
295 /**
296  * goodix_i2c_test - I2C test function to check if the device answers.
297  *
298  * @client: the i2c client
299  */
300 static int goodix_i2c_test(struct i2c_client *client)
301 {
302 	int retry = 0;
303 	int error;
304 	u8 test;
305 
306 	while (retry++ < 2) {
307 		error = goodix_i2c_read(client, GOODIX_REG_CONFIG_DATA,
308 					&test, 1);
309 		if (!error)
310 			return 0;
311 
312 		dev_err(&client->dev, "i2c test failed attempt %d: %d\n",
313 			retry, error);
314 		msleep(20);
315 	}
316 
317 	return error;
318 }
319 
320 /**
321  * goodix_request_input_dev - Allocate, populate and register the input device
322  *
323  * @ts: our goodix_ts_data pointer
324  * @version: device firmware version
325  * @id: device ID
326  *
327  * Must be called during probe
328  */
329 static int goodix_request_input_dev(struct goodix_ts_data *ts, u16 version,
330 				    u16 id)
331 {
332 	int error;
333 
334 	ts->input_dev = devm_input_allocate_device(&ts->client->dev);
335 	if (!ts->input_dev) {
336 		dev_err(&ts->client->dev, "Failed to allocate input device.");
337 		return -ENOMEM;
338 	}
339 
340 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X,
341 			     0, ts->abs_x_max, 0, 0);
342 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y,
343 			     0, ts->abs_y_max, 0, 0);
344 	input_set_abs_params(ts->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
345 	input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
346 
347 	input_mt_init_slots(ts->input_dev, ts->max_touch_num,
348 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
349 
350 	ts->input_dev->name = "Goodix Capacitive TouchScreen";
351 	ts->input_dev->phys = "input/ts";
352 	ts->input_dev->id.bustype = BUS_I2C;
353 	ts->input_dev->id.vendor = 0x0416;
354 	ts->input_dev->id.product = id;
355 	ts->input_dev->id.version = version;
356 
357 	error = input_register_device(ts->input_dev);
358 	if (error) {
359 		dev_err(&ts->client->dev,
360 			"Failed to register input device: %d", error);
361 		return error;
362 	}
363 
364 	return 0;
365 }
366 
367 static int goodix_ts_probe(struct i2c_client *client,
368 			   const struct i2c_device_id *id)
369 {
370 	struct goodix_ts_data *ts;
371 	unsigned long irq_flags;
372 	int error;
373 	u16 version_info, id_info;
374 
375 	dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
376 
377 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
378 		dev_err(&client->dev, "I2C check functionality failed.\n");
379 		return -ENXIO;
380 	}
381 
382 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
383 	if (!ts)
384 		return -ENOMEM;
385 
386 	ts->client = client;
387 	i2c_set_clientdata(client, ts);
388 
389 	error = goodix_i2c_test(client);
390 	if (error) {
391 		dev_err(&client->dev, "I2C communication failure: %d\n", error);
392 		return error;
393 	}
394 
395 	error = goodix_read_version(client, &version_info, &id_info);
396 	if (error) {
397 		dev_err(&client->dev, "Read version failed.\n");
398 		return error;
399 	}
400 
401 	goodix_read_config(ts);
402 
403 	error = goodix_request_input_dev(ts, version_info, id_info);
404 	if (error)
405 		return error;
406 
407 	irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
408 	error = devm_request_threaded_irq(&ts->client->dev, client->irq,
409 					  NULL, goodix_ts_irq_handler,
410 					  irq_flags, client->name, ts);
411 	if (error) {
412 		dev_err(&client->dev, "request IRQ failed: %d\n", error);
413 		return error;
414 	}
415 
416 	return 0;
417 }
418 
419 static const struct i2c_device_id goodix_ts_id[] = {
420 	{ "GDIX1001:00", 0 },
421 	{ }
422 };
423 MODULE_DEVICE_TABLE(i2c, goodix_ts_id);
424 
425 #ifdef CONFIG_ACPI
426 static const struct acpi_device_id goodix_acpi_match[] = {
427 	{ "GDIX1001", 0 },
428 	{ }
429 };
430 MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
431 #endif
432 
433 #ifdef CONFIG_OF
434 static const struct of_device_id goodix_of_match[] = {
435 	{ .compatible = "goodix,gt911" },
436 	{ .compatible = "goodix,gt9110" },
437 	{ .compatible = "goodix,gt912" },
438 	{ .compatible = "goodix,gt927" },
439 	{ .compatible = "goodix,gt9271" },
440 	{ .compatible = "goodix,gt928" },
441 	{ .compatible = "goodix,gt967" },
442 	{ }
443 };
444 MODULE_DEVICE_TABLE(of, goodix_of_match);
445 #endif
446 
447 static struct i2c_driver goodix_ts_driver = {
448 	.probe = goodix_ts_probe,
449 	.id_table = goodix_ts_id,
450 	.driver = {
451 		.name = "Goodix-TS",
452 		.acpi_match_table = ACPI_PTR(goodix_acpi_match),
453 		.of_match_table = of_match_ptr(goodix_of_match),
454 	},
455 };
456 module_i2c_driver(goodix_ts_driver);
457 
458 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
459 MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
460 MODULE_DESCRIPTION("Goodix touchscreen driver");
461 MODULE_LICENSE("GPL v2");
462