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