1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Elo serial touchscreen driver 4 * 5 * Copyright (c) 2004 Vojtech Pavlik 6 */ 7 8 9 /* 10 * This driver can handle serial Elo touchscreens using either the Elo standard 11 * 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo 12 * legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol. 13 */ 14 15 #include <linux/errno.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/input.h> 20 #include <linux/serio.h> 21 #include <linux/ctype.h> 22 23 #define DRIVER_DESC "Elo serial touchscreen driver" 24 25 MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>"); 26 MODULE_DESCRIPTION(DRIVER_DESC); 27 MODULE_LICENSE("GPL"); 28 29 /* 30 * Definitions & global arrays. 31 */ 32 33 #define ELO_MAX_LENGTH 10 34 35 #define ELO10_PACKET_LEN 8 36 #define ELO10_TOUCH 0x03 37 #define ELO10_PRESSURE 0x80 38 39 #define ELO10_LEAD_BYTE 'U' 40 41 #define ELO10_ID_CMD 'i' 42 43 #define ELO10_TOUCH_PACKET 'T' 44 #define ELO10_ACK_PACKET 'A' 45 #define ELI10_ID_PACKET 'I' 46 47 /* 48 * Per-touchscreen data. 49 */ 50 51 struct elo { 52 struct input_dev *dev; 53 struct serio *serio; 54 struct mutex cmd_mutex; 55 struct completion cmd_done; 56 int id; 57 int idx; 58 unsigned char expected_packet; 59 unsigned char csum; 60 unsigned char data[ELO_MAX_LENGTH]; 61 unsigned char response[ELO10_PACKET_LEN]; 62 char phys[32]; 63 }; 64 65 static void elo_process_data_10(struct elo *elo, unsigned char data) 66 { 67 struct input_dev *dev = elo->dev; 68 69 elo->data[elo->idx] = data; 70 71 switch (elo->idx++) { 72 case 0: 73 elo->csum = 0xaa; 74 if (data != ELO10_LEAD_BYTE) { 75 dev_dbg(&elo->serio->dev, 76 "unsynchronized data: 0x%02x\n", data); 77 elo->idx = 0; 78 } 79 break; 80 81 case 9: 82 elo->idx = 0; 83 if (data != elo->csum) { 84 dev_dbg(&elo->serio->dev, 85 "bad checksum: 0x%02x, expected 0x%02x\n", 86 data, elo->csum); 87 break; 88 } 89 if (elo->data[1] != elo->expected_packet) { 90 if (elo->data[1] != ELO10_TOUCH_PACKET) 91 dev_dbg(&elo->serio->dev, 92 "unexpected packet: 0x%02x\n", 93 elo->data[1]); 94 break; 95 } 96 if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) { 97 input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]); 98 input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]); 99 if (elo->data[2] & ELO10_PRESSURE) 100 input_report_abs(dev, ABS_PRESSURE, 101 (elo->data[8] << 8) | elo->data[7]); 102 input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH); 103 input_sync(dev); 104 } else if (elo->data[1] == ELO10_ACK_PACKET) { 105 if (elo->data[2] == '0') 106 elo->expected_packet = ELO10_TOUCH_PACKET; 107 complete(&elo->cmd_done); 108 } else { 109 memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN); 110 elo->expected_packet = ELO10_ACK_PACKET; 111 } 112 break; 113 } 114 elo->csum += data; 115 } 116 117 static void elo_process_data_6(struct elo *elo, unsigned char data) 118 { 119 struct input_dev *dev = elo->dev; 120 121 elo->data[elo->idx] = data; 122 123 switch (elo->idx++) { 124 125 case 0: 126 if ((data & 0xc0) != 0xc0) 127 elo->idx = 0; 128 break; 129 130 case 1: 131 if ((data & 0xc0) != 0x80) 132 elo->idx = 0; 133 break; 134 135 case 2: 136 if ((data & 0xc0) != 0x40) 137 elo->idx = 0; 138 break; 139 140 case 3: 141 if (data & 0xc0) { 142 elo->idx = 0; 143 break; 144 } 145 146 input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f)); 147 input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f)); 148 149 if (elo->id == 2) { 150 input_report_key(dev, BTN_TOUCH, 1); 151 input_sync(dev); 152 elo->idx = 0; 153 } 154 155 break; 156 157 case 4: 158 if (data) { 159 input_sync(dev); 160 elo->idx = 0; 161 } 162 break; 163 164 case 5: 165 if ((data & 0xf0) == 0) { 166 input_report_abs(dev, ABS_PRESSURE, elo->data[5]); 167 input_report_key(dev, BTN_TOUCH, !!elo->data[5]); 168 } 169 input_sync(dev); 170 elo->idx = 0; 171 break; 172 } 173 } 174 175 static void elo_process_data_3(struct elo *elo, unsigned char data) 176 { 177 struct input_dev *dev = elo->dev; 178 179 elo->data[elo->idx] = data; 180 181 switch (elo->idx++) { 182 183 case 0: 184 if ((data & 0x7f) != 0x01) 185 elo->idx = 0; 186 break; 187 case 2: 188 input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80)); 189 input_report_abs(dev, ABS_X, elo->data[1]); 190 input_report_abs(dev, ABS_Y, elo->data[2]); 191 input_sync(dev); 192 elo->idx = 0; 193 break; 194 } 195 } 196 197 static irqreturn_t elo_interrupt(struct serio *serio, 198 unsigned char data, unsigned int flags) 199 { 200 struct elo *elo = serio_get_drvdata(serio); 201 202 switch (elo->id) { 203 case 0: 204 elo_process_data_10(elo, data); 205 break; 206 207 case 1: 208 case 2: 209 elo_process_data_6(elo, data); 210 break; 211 212 case 3: 213 elo_process_data_3(elo, data); 214 break; 215 } 216 217 return IRQ_HANDLED; 218 } 219 220 static int elo_command_10(struct elo *elo, unsigned char *packet) 221 { 222 int rc = -1; 223 int i; 224 unsigned char csum = 0xaa + ELO10_LEAD_BYTE; 225 226 mutex_lock(&elo->cmd_mutex); 227 228 serio_pause_rx(elo->serio); 229 elo->expected_packet = toupper(packet[0]); 230 init_completion(&elo->cmd_done); 231 serio_continue_rx(elo->serio); 232 233 if (serio_write(elo->serio, ELO10_LEAD_BYTE)) 234 goto out; 235 236 for (i = 0; i < ELO10_PACKET_LEN; i++) { 237 csum += packet[i]; 238 if (serio_write(elo->serio, packet[i])) 239 goto out; 240 } 241 242 if (serio_write(elo->serio, csum)) 243 goto out; 244 245 wait_for_completion_timeout(&elo->cmd_done, HZ); 246 247 if (elo->expected_packet == ELO10_TOUCH_PACKET) { 248 /* We are back in reporting mode, the command was ACKed */ 249 memcpy(packet, elo->response, ELO10_PACKET_LEN); 250 rc = 0; 251 } 252 253 out: 254 mutex_unlock(&elo->cmd_mutex); 255 return rc; 256 } 257 258 static int elo_setup_10(struct elo *elo) 259 { 260 static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" }; 261 struct input_dev *dev = elo->dev; 262 unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD }; 263 264 if (elo_command_10(elo, packet)) 265 return -1; 266 267 dev->id.version = (packet[5] << 8) | packet[4]; 268 269 input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0); 270 input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0); 271 if (packet[3] & ELO10_PRESSURE) 272 input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0); 273 274 dev_info(&elo->serio->dev, 275 "%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n", 276 elo_types[(packet[1] -'0') & 0x03], 277 packet[5], packet[4], packet[3], packet[7]); 278 279 return 0; 280 } 281 282 /* 283 * elo_disconnect() is the opposite of elo_connect() 284 */ 285 286 static void elo_disconnect(struct serio *serio) 287 { 288 struct elo *elo = serio_get_drvdata(serio); 289 290 input_get_device(elo->dev); 291 input_unregister_device(elo->dev); 292 serio_close(serio); 293 serio_set_drvdata(serio, NULL); 294 input_put_device(elo->dev); 295 kfree(elo); 296 } 297 298 /* 299 * elo_connect() is the routine that is called when someone adds a 300 * new serio device that supports Gunze protocol and registers it as 301 * an input device. 302 */ 303 304 static int elo_connect(struct serio *serio, struct serio_driver *drv) 305 { 306 struct elo *elo; 307 struct input_dev *input_dev; 308 int err; 309 310 elo = kzalloc(sizeof(struct elo), GFP_KERNEL); 311 input_dev = input_allocate_device(); 312 if (!elo || !input_dev) { 313 err = -ENOMEM; 314 goto fail1; 315 } 316 317 elo->serio = serio; 318 elo->id = serio->id.id; 319 elo->dev = input_dev; 320 elo->expected_packet = ELO10_TOUCH_PACKET; 321 mutex_init(&elo->cmd_mutex); 322 init_completion(&elo->cmd_done); 323 snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys); 324 325 input_dev->name = "Elo Serial TouchScreen"; 326 input_dev->phys = elo->phys; 327 input_dev->id.bustype = BUS_RS232; 328 input_dev->id.vendor = SERIO_ELO; 329 input_dev->id.product = elo->id; 330 input_dev->id.version = 0x0100; 331 input_dev->dev.parent = &serio->dev; 332 333 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS); 334 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH); 335 336 serio_set_drvdata(serio, elo); 337 err = serio_open(serio, drv); 338 if (err) 339 goto fail2; 340 341 switch (elo->id) { 342 343 case 0: /* 10-byte protocol */ 344 if (elo_setup_10(elo)) { 345 err = -EIO; 346 goto fail3; 347 } 348 349 break; 350 351 case 1: /* 6-byte protocol */ 352 input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0); 353 fallthrough; 354 355 case 2: /* 4-byte protocol */ 356 input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0); 357 input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0); 358 break; 359 360 case 3: /* 3-byte protocol */ 361 input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0); 362 input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0); 363 break; 364 } 365 366 err = input_register_device(elo->dev); 367 if (err) 368 goto fail3; 369 370 return 0; 371 372 fail3: serio_close(serio); 373 fail2: serio_set_drvdata(serio, NULL); 374 fail1: input_free_device(input_dev); 375 kfree(elo); 376 return err; 377 } 378 379 /* 380 * The serio driver structure. 381 */ 382 383 static const struct serio_device_id elo_serio_ids[] = { 384 { 385 .type = SERIO_RS232, 386 .proto = SERIO_ELO, 387 .id = SERIO_ANY, 388 .extra = SERIO_ANY, 389 }, 390 { 0 } 391 }; 392 393 MODULE_DEVICE_TABLE(serio, elo_serio_ids); 394 395 static struct serio_driver elo_drv = { 396 .driver = { 397 .name = "elo", 398 }, 399 .description = DRIVER_DESC, 400 .id_table = elo_serio_ids, 401 .interrupt = elo_interrupt, 402 .connect = elo_connect, 403 .disconnect = elo_disconnect, 404 }; 405 406 module_serio_driver(elo_drv); 407