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/i2c.h>
19 #include <linux/input.h>
20 #include <linux/input/mt.h>
21 #include <linux/module.h>
22 #include <linux/delay.h>
23 #include <linux/irq.h>
24 #include <linux/interrupt.h>
25 #include <linux/slab.h>
26 #include <asm/unaligned.h>
27 
28 struct goodix_ts_data {
29 	struct i2c_client *client;
30 	struct input_dev *input_dev;
31 	int abs_x_max;
32 	int abs_y_max;
33 	unsigned int max_touch_num;
34 	unsigned int int_trigger_type;
35 };
36 
37 #define GOODIX_MAX_HEIGHT		4096
38 #define GOODIX_MAX_WIDTH		4096
39 #define GOODIX_INT_TRIGGER		1
40 #define GOODIX_CONTACT_SIZE		8
41 #define GOODIX_MAX_CONTACTS		10
42 
43 #define GOODIX_CONFIG_MAX_LENGTH	240
44 
45 /* Register defines */
46 #define GOODIX_READ_COOR_ADDR		0x814E
47 #define GOODIX_REG_CONFIG_DATA		0x8047
48 #define GOODIX_REG_VERSION		0x8140
49 
50 #define RESOLUTION_LOC		1
51 #define TRIGGER_LOC		6
52 
53 static const unsigned long goodix_irq_flags[] = {
54 	IRQ_TYPE_EDGE_RISING,
55 	IRQ_TYPE_EDGE_FALLING,
56 	IRQ_TYPE_LEVEL_LOW,
57 	IRQ_TYPE_LEVEL_HIGH,
58 };
59 
60 /**
61  * goodix_i2c_read - read data from a register of the i2c slave device.
62  *
63  * @client: i2c device.
64  * @reg: the register to read from.
65  * @buf: raw write data buffer.
66  * @len: length of the buffer to write
67  */
68 static int goodix_i2c_read(struct i2c_client *client,
69 				u16 reg, u8 *buf, int len)
70 {
71 	struct i2c_msg msgs[2];
72 	u16 wbuf = cpu_to_be16(reg);
73 	int ret;
74 
75 	msgs[0].flags = 0;
76 	msgs[0].addr  = client->addr;
77 	msgs[0].len   = 2;
78 	msgs[0].buf   = (u8 *) &wbuf;
79 
80 	msgs[1].flags = I2C_M_RD;
81 	msgs[1].addr  = client->addr;
82 	msgs[1].len   = len;
83 	msgs[1].buf   = buf;
84 
85 	ret = i2c_transfer(client->adapter, msgs, 2);
86 	return ret < 0 ? ret : (ret != ARRAY_SIZE(msgs) ? -EIO : 0);
87 }
88 
89 static int goodix_ts_read_input_report(struct goodix_ts_data *ts, u8 *data)
90 {
91 	int touch_num;
92 	int error;
93 
94 	error = goodix_i2c_read(ts->client, GOODIX_READ_COOR_ADDR, data,
95 				GOODIX_CONTACT_SIZE + 1);
96 	if (error) {
97 		dev_err(&ts->client->dev, "I2C transfer error: %d\n", error);
98 		return error;
99 	}
100 
101 	touch_num = data[0] & 0x0f;
102 	if (touch_num > GOODIX_MAX_CONTACTS)
103 		return -EPROTO;
104 
105 	if (touch_num > 1) {
106 		data += 1 + GOODIX_CONTACT_SIZE;
107 		error = goodix_i2c_read(ts->client,
108 					GOODIX_READ_COOR_ADDR +
109 						1 + GOODIX_CONTACT_SIZE,
110 					data,
111 					GOODIX_CONTACT_SIZE * (touch_num - 1));
112 		if (error)
113 			return error;
114 	}
115 
116 	return touch_num;
117 }
118 
119 static void goodix_ts_report_touch(struct goodix_ts_data *ts, u8 *coor_data)
120 {
121 	int id = coor_data[0] & 0x0F;
122 	int input_x = get_unaligned_le16(&coor_data[1]);
123 	int input_y = get_unaligned_le16(&coor_data[3]);
124 	int input_w = get_unaligned_le16(&coor_data[5]);
125 
126 	input_mt_slot(ts->input_dev, id);
127 	input_mt_report_slot_state(ts->input_dev, MT_TOOL_FINGER, true);
128 	input_report_abs(ts->input_dev, ABS_MT_POSITION_X, input_x);
129 	input_report_abs(ts->input_dev, ABS_MT_POSITION_Y, input_y);
130 	input_report_abs(ts->input_dev, ABS_MT_TOUCH_MAJOR, input_w);
131 	input_report_abs(ts->input_dev, ABS_MT_WIDTH_MAJOR, input_w);
132 }
133 
134 /**
135  * goodix_process_events - Process incoming events
136  *
137  * @ts: our goodix_ts_data pointer
138  *
139  * Called when the IRQ is triggered. Read the current device state, and push
140  * the input events to the user space.
141  */
142 static void goodix_process_events(struct goodix_ts_data *ts)
143 {
144 	u8  point_data[1 + GOODIX_CONTACT_SIZE * GOODIX_MAX_CONTACTS];
145 	int touch_num;
146 	int i;
147 
148 	touch_num = goodix_ts_read_input_report(ts, point_data);
149 	if (touch_num < 0)
150 		return;
151 
152 	for (i = 0; i < touch_num; i++)
153 		goodix_ts_report_touch(ts,
154 				&point_data[1 + GOODIX_CONTACT_SIZE * i]);
155 
156 	input_mt_sync_frame(ts->input_dev);
157 	input_sync(ts->input_dev);
158 }
159 
160 /**
161  * goodix_ts_irq_handler - The IRQ handler
162  *
163  * @irq: interrupt number.
164  * @dev_id: private data pointer.
165  */
166 static irqreturn_t goodix_ts_irq_handler(int irq, void *dev_id)
167 {
168 	static const u8 end_cmd[] = {
169 		GOODIX_READ_COOR_ADDR >> 8,
170 		GOODIX_READ_COOR_ADDR & 0xff,
171 		0
172 	};
173 	struct goodix_ts_data *ts = dev_id;
174 
175 	goodix_process_events(ts);
176 
177 	if (i2c_master_send(ts->client, end_cmd, sizeof(end_cmd)) < 0)
178 		dev_err(&ts->client->dev, "I2C write end_cmd error\n");
179 
180 	return IRQ_HANDLED;
181 }
182 
183 /**
184  * goodix_read_config - Read the embedded configuration of the panel
185  *
186  * @ts: our goodix_ts_data pointer
187  *
188  * Must be called during probe
189  */
190 static void goodix_read_config(struct goodix_ts_data *ts)
191 {
192 	u8 config[GOODIX_CONFIG_MAX_LENGTH];
193 	int error;
194 
195 	error = goodix_i2c_read(ts->client, GOODIX_REG_CONFIG_DATA,
196 			      config,
197 			   GOODIX_CONFIG_MAX_LENGTH);
198 	if (error) {
199 		dev_warn(&ts->client->dev,
200 			 "Error reading config (%d), using defaults\n",
201 			 error);
202 		ts->abs_x_max = GOODIX_MAX_WIDTH;
203 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
204 		ts->int_trigger_type = GOODIX_INT_TRIGGER;
205 		return;
206 	}
207 
208 	ts->abs_x_max = get_unaligned_le16(&config[RESOLUTION_LOC]);
209 	ts->abs_y_max = get_unaligned_le16(&config[RESOLUTION_LOC + 2]);
210 	ts->int_trigger_type = (config[TRIGGER_LOC]) & 0x03;
211 	if (!ts->abs_x_max || !ts->abs_y_max) {
212 		dev_err(&ts->client->dev,
213 			"Invalid config, using defaults\n");
214 		ts->abs_x_max = GOODIX_MAX_WIDTH;
215 		ts->abs_y_max = GOODIX_MAX_HEIGHT;
216 	}
217 }
218 
219 
220 /**
221  * goodix_read_version - Read goodix touchscreen version
222  *
223  * @client: the i2c client
224  * @version: output buffer containing the version on success
225  */
226 static int goodix_read_version(struct i2c_client *client, u16 *version)
227 {
228 	int error;
229 	u8 buf[6];
230 
231 	error = goodix_i2c_read(client, GOODIX_REG_VERSION, buf, sizeof(buf));
232 	if (error) {
233 		dev_err(&client->dev, "read version failed: %d\n", error);
234 		return error;
235 	}
236 
237 	if (version)
238 		*version = get_unaligned_le16(&buf[4]);
239 
240 	dev_info(&client->dev, "IC VERSION: %6ph\n", buf);
241 
242 	return 0;
243 }
244 
245 /**
246  * goodix_i2c_test - I2C test function to check if the device answers.
247  *
248  * @client: the i2c client
249  */
250 static int goodix_i2c_test(struct i2c_client *client)
251 {
252 	int retry = 0;
253 	int error;
254 	u8 test;
255 
256 	while (retry++ < 2) {
257 		error = goodix_i2c_read(client, GOODIX_REG_CONFIG_DATA,
258 					&test, 1);
259 		if (!error)
260 			return 0;
261 
262 		dev_err(&client->dev, "i2c test failed attempt %d: %d\n",
263 			retry, error);
264 		msleep(20);
265 	}
266 
267 	return error;
268 }
269 
270 /**
271  * goodix_request_input_dev - Allocate, populate and register the input device
272  *
273  * @ts: our goodix_ts_data pointer
274  *
275  * Must be called during probe
276  */
277 static int goodix_request_input_dev(struct goodix_ts_data *ts)
278 {
279 	int error;
280 
281 	ts->input_dev = devm_input_allocate_device(&ts->client->dev);
282 	if (!ts->input_dev) {
283 		dev_err(&ts->client->dev, "Failed to allocate input device.");
284 		return -ENOMEM;
285 	}
286 
287 	ts->input_dev->evbit[0] = BIT_MASK(EV_SYN) |
288 				  BIT_MASK(EV_KEY) |
289 				  BIT_MASK(EV_ABS);
290 
291 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_X, 0,
292 				ts->abs_x_max, 0, 0);
293 	input_set_abs_params(ts->input_dev, ABS_MT_POSITION_Y, 0,
294 				ts->abs_y_max, 0, 0);
295 	input_set_abs_params(ts->input_dev, ABS_MT_WIDTH_MAJOR, 0, 255, 0, 0);
296 	input_set_abs_params(ts->input_dev, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
297 
298 	input_mt_init_slots(ts->input_dev, GOODIX_MAX_CONTACTS,
299 			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
300 
301 	ts->input_dev->name = "Goodix Capacitive TouchScreen";
302 	ts->input_dev->phys = "input/ts";
303 	ts->input_dev->id.bustype = BUS_I2C;
304 	ts->input_dev->id.vendor = 0x0416;
305 	ts->input_dev->id.product = 0x1001;
306 	ts->input_dev->id.version = 10427;
307 
308 	error = input_register_device(ts->input_dev);
309 	if (error) {
310 		dev_err(&ts->client->dev,
311 			"Failed to register input device: %d", error);
312 		return error;
313 	}
314 
315 	return 0;
316 }
317 
318 static int goodix_ts_probe(struct i2c_client *client,
319 			   const struct i2c_device_id *id)
320 {
321 	struct goodix_ts_data *ts;
322 	unsigned long irq_flags;
323 	int error;
324 	u16 version_info;
325 
326 	dev_dbg(&client->dev, "I2C Address: 0x%02x\n", client->addr);
327 
328 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
329 		dev_err(&client->dev, "I2C check functionality failed.\n");
330 		return -ENXIO;
331 	}
332 
333 	ts = devm_kzalloc(&client->dev, sizeof(*ts), GFP_KERNEL);
334 	if (!ts)
335 		return -ENOMEM;
336 
337 	ts->client = client;
338 	i2c_set_clientdata(client, ts);
339 
340 	error = goodix_i2c_test(client);
341 	if (error) {
342 		dev_err(&client->dev, "I2C communication failure: %d\n", error);
343 		return error;
344 	}
345 
346 	error = goodix_read_version(client, &version_info);
347 	if (error) {
348 		dev_err(&client->dev, "Read version failed.\n");
349 		return error;
350 	}
351 
352 	goodix_read_config(ts);
353 
354 	error = goodix_request_input_dev(ts);
355 	if (error)
356 		return error;
357 
358 	irq_flags = goodix_irq_flags[ts->int_trigger_type] | IRQF_ONESHOT;
359 	error = devm_request_threaded_irq(&ts->client->dev, client->irq,
360 					  NULL, goodix_ts_irq_handler,
361 					  irq_flags, client->name, ts);
362 	if (error) {
363 		dev_err(&client->dev, "request IRQ failed: %d\n", error);
364 		return error;
365 	}
366 
367 	return 0;
368 }
369 
370 static const struct i2c_device_id goodix_ts_id[] = {
371 	{ "GDIX1001:00", 0 },
372 	{ }
373 };
374 
375 static const struct acpi_device_id goodix_acpi_match[] = {
376 	{ "GDIX1001", 0 },
377 	{ }
378 };
379 MODULE_DEVICE_TABLE(acpi, goodix_acpi_match);
380 
381 static struct i2c_driver goodix_ts_driver = {
382 	.probe = goodix_ts_probe,
383 	.id_table = goodix_ts_id,
384 	.driver = {
385 		.name = "Goodix-TS",
386 		.owner = THIS_MODULE,
387 		.acpi_match_table = goodix_acpi_match,
388 	},
389 };
390 module_i2c_driver(goodix_ts_driver);
391 
392 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
393 MODULE_AUTHOR("Bastien Nocera <hadess@hadess.net>");
394 MODULE_DESCRIPTION("Goodix touchscreen driver");
395 MODULE_LICENSE("GPL v2");
396