1 /* 2 * HID over I2C protocol implementation 3 * 4 * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com> 5 * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France 6 * Copyright (c) 2012 Red Hat, Inc 7 * 8 * This code is partly based on "USB HID support for Linux": 9 * 10 * Copyright (c) 1999 Andreas Gal 11 * Copyright (c) 2000-2005 Vojtech Pavlik <vojtech@suse.cz> 12 * Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc 13 * Copyright (c) 2007-2008 Oliver Neukum 14 * Copyright (c) 2006-2010 Jiri Kosina 15 * 16 * This file is subject to the terms and conditions of the GNU General Public 17 * License. See the file COPYING in the main directory of this archive for 18 * more details. 19 */ 20 21 #include <linux/module.h> 22 #include <linux/i2c.h> 23 #include <linux/interrupt.h> 24 #include <linux/input.h> 25 #include <linux/irq.h> 26 #include <linux/delay.h> 27 #include <linux/slab.h> 28 #include <linux/pm.h> 29 #include <linux/pm_wakeirq.h> 30 #include <linux/device.h> 31 #include <linux/wait.h> 32 #include <linux/err.h> 33 #include <linux/string.h> 34 #include <linux/list.h> 35 #include <linux/jiffies.h> 36 #include <linux/kernel.h> 37 #include <linux/hid.h> 38 #include <linux/mutex.h> 39 #include <asm/unaligned.h> 40 41 #include <drm/drm_panel.h> 42 43 #include "../hid-ids.h" 44 #include "i2c-hid.h" 45 46 /* quirks to control the device */ 47 #define I2C_HID_QUIRK_NO_IRQ_AFTER_RESET BIT(0) 48 #define I2C_HID_QUIRK_BOGUS_IRQ BIT(1) 49 #define I2C_HID_QUIRK_RESET_ON_RESUME BIT(2) 50 #define I2C_HID_QUIRK_BAD_INPUT_SIZE BIT(3) 51 #define I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET BIT(4) 52 #define I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND BIT(5) 53 54 /* Command opcodes */ 55 #define I2C_HID_OPCODE_RESET 0x01 56 #define I2C_HID_OPCODE_GET_REPORT 0x02 57 #define I2C_HID_OPCODE_SET_REPORT 0x03 58 #define I2C_HID_OPCODE_GET_IDLE 0x04 59 #define I2C_HID_OPCODE_SET_IDLE 0x05 60 #define I2C_HID_OPCODE_GET_PROTOCOL 0x06 61 #define I2C_HID_OPCODE_SET_PROTOCOL 0x07 62 #define I2C_HID_OPCODE_SET_POWER 0x08 63 64 /* flags */ 65 #define I2C_HID_STARTED 0 66 #define I2C_HID_RESET_PENDING 1 67 68 #define I2C_HID_PWR_ON 0x00 69 #define I2C_HID_PWR_SLEEP 0x01 70 71 #define i2c_hid_dbg(ihid, ...) dev_dbg(&(ihid)->client->dev, __VA_ARGS__) 72 73 struct i2c_hid_desc { 74 __le16 wHIDDescLength; 75 __le16 bcdVersion; 76 __le16 wReportDescLength; 77 __le16 wReportDescRegister; 78 __le16 wInputRegister; 79 __le16 wMaxInputLength; 80 __le16 wOutputRegister; 81 __le16 wMaxOutputLength; 82 __le16 wCommandRegister; 83 __le16 wDataRegister; 84 __le16 wVendorID; 85 __le16 wProductID; 86 __le16 wVersionID; 87 __le32 reserved; 88 } __packed; 89 90 /* The main device structure */ 91 struct i2c_hid { 92 struct i2c_client *client; /* i2c client */ 93 struct hid_device *hid; /* pointer to corresponding HID dev */ 94 struct i2c_hid_desc hdesc; /* the HID Descriptor */ 95 __le16 wHIDDescRegister; /* location of the i2c 96 * register of the HID 97 * descriptor. */ 98 unsigned int bufsize; /* i2c buffer size */ 99 u8 *inbuf; /* Input buffer */ 100 u8 *rawbuf; /* Raw Input buffer */ 101 u8 *cmdbuf; /* Command buffer */ 102 103 unsigned long flags; /* device flags */ 104 unsigned long quirks; /* Various quirks */ 105 106 wait_queue_head_t wait; /* For waiting the interrupt */ 107 108 struct mutex reset_lock; 109 110 struct i2chid_ops *ops; 111 struct drm_panel_follower panel_follower; 112 struct work_struct panel_follower_prepare_work; 113 bool is_panel_follower; 114 bool prepare_work_finished; 115 }; 116 117 static const struct i2c_hid_quirks { 118 __u16 idVendor; 119 __u16 idProduct; 120 __u32 quirks; 121 } i2c_hid_quirks[] = { 122 { I2C_VENDOR_ID_HANTICK, I2C_PRODUCT_ID_HANTICK_5288, 123 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 124 { I2C_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_VOYO_WINPAD_A15, 125 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 126 { I2C_VENDOR_ID_RAYDIUM, I2C_PRODUCT_ID_RAYDIUM_3118, 127 I2C_HID_QUIRK_NO_IRQ_AFTER_RESET }, 128 { USB_VENDOR_ID_ALPS_JP, HID_ANY_ID, 129 I2C_HID_QUIRK_RESET_ON_RESUME }, 130 { I2C_VENDOR_ID_SYNAPTICS, I2C_PRODUCT_ID_SYNAPTICS_SYNA2393, 131 I2C_HID_QUIRK_RESET_ON_RESUME }, 132 { USB_VENDOR_ID_ITE, I2C_DEVICE_ID_ITE_LENOVO_LEGION_Y720, 133 I2C_HID_QUIRK_BAD_INPUT_SIZE }, 134 { I2C_VENDOR_ID_CIRQUE, I2C_PRODUCT_ID_CIRQUE_1063, 135 I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND }, 136 /* 137 * Sending the wakeup after reset actually break ELAN touchscreen controller 138 */ 139 { USB_VENDOR_ID_ELAN, HID_ANY_ID, 140 I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET | 141 I2C_HID_QUIRK_BOGUS_IRQ }, 142 { 0, 0 } 143 }; 144 145 /* 146 * i2c_hid_lookup_quirk: return any quirks associated with a I2C HID device 147 * @idVendor: the 16-bit vendor ID 148 * @idProduct: the 16-bit product ID 149 * 150 * Returns: a u32 quirks value. 151 */ 152 static u32 i2c_hid_lookup_quirk(const u16 idVendor, const u16 idProduct) 153 { 154 u32 quirks = 0; 155 int n; 156 157 for (n = 0; i2c_hid_quirks[n].idVendor; n++) 158 if (i2c_hid_quirks[n].idVendor == idVendor && 159 (i2c_hid_quirks[n].idProduct == (__u16)HID_ANY_ID || 160 i2c_hid_quirks[n].idProduct == idProduct)) 161 quirks = i2c_hid_quirks[n].quirks; 162 163 return quirks; 164 } 165 166 static int i2c_hid_probe_address(struct i2c_hid *ihid) 167 { 168 int ret; 169 170 /* 171 * Some STM-based devices need 400µs after a rising clock edge to wake 172 * from deep sleep, in which case the first read will fail. Try after a 173 * short sleep to see if the device came alive on the bus. Certain 174 * Weida Tech devices also need this. 175 */ 176 ret = i2c_smbus_read_byte(ihid->client); 177 if (ret < 0) { 178 usleep_range(400, 500); 179 ret = i2c_smbus_read_byte(ihid->client); 180 } 181 return ret < 0 ? ret : 0; 182 } 183 184 static int i2c_hid_xfer(struct i2c_hid *ihid, 185 u8 *send_buf, int send_len, u8 *recv_buf, int recv_len) 186 { 187 struct i2c_client *client = ihid->client; 188 struct i2c_msg msgs[2] = { 0 }; 189 int n = 0; 190 int ret; 191 192 if (send_len) { 193 i2c_hid_dbg(ihid, "%s: cmd=%*ph\n", 194 __func__, send_len, send_buf); 195 196 msgs[n].addr = client->addr; 197 msgs[n].flags = (client->flags & I2C_M_TEN) | I2C_M_DMA_SAFE; 198 msgs[n].len = send_len; 199 msgs[n].buf = send_buf; 200 n++; 201 } 202 203 if (recv_len) { 204 msgs[n].addr = client->addr; 205 msgs[n].flags = (client->flags & I2C_M_TEN) | 206 I2C_M_RD | I2C_M_DMA_SAFE; 207 msgs[n].len = recv_len; 208 msgs[n].buf = recv_buf; 209 n++; 210 } 211 212 ret = i2c_transfer(client->adapter, msgs, n); 213 214 if (ret != n) 215 return ret < 0 ? ret : -EIO; 216 217 return 0; 218 } 219 220 static int i2c_hid_read_register(struct i2c_hid *ihid, __le16 reg, 221 void *buf, size_t len) 222 { 223 *(__le16 *)ihid->cmdbuf = reg; 224 225 return i2c_hid_xfer(ihid, ihid->cmdbuf, sizeof(__le16), buf, len); 226 } 227 228 static size_t i2c_hid_encode_command(u8 *buf, u8 opcode, 229 int report_type, int report_id) 230 { 231 size_t length = 0; 232 233 if (report_id < 0x0F) { 234 buf[length++] = report_type << 4 | report_id; 235 buf[length++] = opcode; 236 } else { 237 buf[length++] = report_type << 4 | 0x0F; 238 buf[length++] = opcode; 239 buf[length++] = report_id; 240 } 241 242 return length; 243 } 244 245 static int i2c_hid_get_report(struct i2c_hid *ihid, 246 u8 report_type, u8 report_id, 247 u8 *recv_buf, size_t recv_len) 248 { 249 size_t length = 0; 250 size_t ret_count; 251 int error; 252 253 i2c_hid_dbg(ihid, "%s\n", __func__); 254 255 /* Command register goes first */ 256 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 257 length += sizeof(__le16); 258 /* Next is GET_REPORT command */ 259 length += i2c_hid_encode_command(ihid->cmdbuf + length, 260 I2C_HID_OPCODE_GET_REPORT, 261 report_type, report_id); 262 /* 263 * Device will send report data through data register. Because 264 * command can be either 2 or 3 bytes destination for the data 265 * register may be not aligned. 266 */ 267 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 268 ihid->cmdbuf + length); 269 length += sizeof(__le16); 270 271 /* 272 * In addition to report data device will supply data length 273 * in the first 2 bytes of the response, so adjust . 274 */ 275 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, 276 ihid->rawbuf, recv_len + sizeof(__le16)); 277 if (error) { 278 dev_err(&ihid->client->dev, 279 "failed to set a report to device: %d\n", error); 280 return error; 281 } 282 283 /* The buffer is sufficiently aligned */ 284 ret_count = le16_to_cpup((__le16 *)ihid->rawbuf); 285 286 /* Check for empty report response */ 287 if (ret_count <= sizeof(__le16)) 288 return 0; 289 290 recv_len = min(recv_len, ret_count - sizeof(__le16)); 291 memcpy(recv_buf, ihid->rawbuf + sizeof(__le16), recv_len); 292 293 if (report_id && recv_len != 0 && recv_buf[0] != report_id) { 294 dev_err(&ihid->client->dev, 295 "device returned incorrect report (%d vs %d expected)\n", 296 recv_buf[0], report_id); 297 return -EINVAL; 298 } 299 300 return recv_len; 301 } 302 303 static size_t i2c_hid_format_report(u8 *buf, int report_id, 304 const u8 *data, size_t size) 305 { 306 size_t length = sizeof(__le16); /* reserve space to store size */ 307 308 if (report_id) 309 buf[length++] = report_id; 310 311 memcpy(buf + length, data, size); 312 length += size; 313 314 /* Store overall size in the beginning of the buffer */ 315 put_unaligned_le16(length, buf); 316 317 return length; 318 } 319 320 /** 321 * i2c_hid_set_or_send_report: forward an incoming report to the device 322 * @ihid: the i2c hid device 323 * @report_type: 0x03 for HID_FEATURE_REPORT ; 0x02 for HID_OUTPUT_REPORT 324 * @report_id: the report ID 325 * @buf: the actual data to transfer, without the report ID 326 * @data_len: size of buf 327 * @do_set: true: use SET_REPORT HID command, false: send plain OUTPUT report 328 */ 329 static int i2c_hid_set_or_send_report(struct i2c_hid *ihid, 330 u8 report_type, u8 report_id, 331 const u8 *buf, size_t data_len, 332 bool do_set) 333 { 334 size_t length = 0; 335 int error; 336 337 i2c_hid_dbg(ihid, "%s\n", __func__); 338 339 if (data_len > ihid->bufsize) 340 return -EINVAL; 341 342 if (!do_set && le16_to_cpu(ihid->hdesc.wMaxOutputLength) == 0) 343 return -ENOSYS; 344 345 if (do_set) { 346 /* Command register goes first */ 347 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 348 length += sizeof(__le16); 349 /* Next is SET_REPORT command */ 350 length += i2c_hid_encode_command(ihid->cmdbuf + length, 351 I2C_HID_OPCODE_SET_REPORT, 352 report_type, report_id); 353 /* 354 * Report data will go into the data register. Because 355 * command can be either 2 or 3 bytes destination for 356 * the data register may be not aligned. 357 */ 358 put_unaligned_le16(le16_to_cpu(ihid->hdesc.wDataRegister), 359 ihid->cmdbuf + length); 360 length += sizeof(__le16); 361 } else { 362 /* 363 * With simple "send report" all data goes into the output 364 * register. 365 */ 366 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wOutputRegister; 367 length += sizeof(__le16); 368 } 369 370 length += i2c_hid_format_report(ihid->cmdbuf + length, 371 report_id, buf, data_len); 372 373 error = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 374 if (error) { 375 dev_err(&ihid->client->dev, 376 "failed to set a report to device: %d\n", error); 377 return error; 378 } 379 380 return data_len; 381 } 382 383 static int i2c_hid_set_power_command(struct i2c_hid *ihid, int power_state) 384 { 385 size_t length; 386 387 /* SET_POWER uses command register */ 388 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 389 length = sizeof(__le16); 390 391 /* Now the command itself */ 392 length += i2c_hid_encode_command(ihid->cmdbuf + length, 393 I2C_HID_OPCODE_SET_POWER, 394 0, power_state); 395 396 return i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 397 } 398 399 static int i2c_hid_set_power(struct i2c_hid *ihid, int power_state) 400 { 401 int ret; 402 403 i2c_hid_dbg(ihid, "%s\n", __func__); 404 405 ret = i2c_hid_set_power_command(ihid, power_state); 406 if (ret) 407 dev_err(&ihid->client->dev, 408 "failed to change power setting.\n"); 409 410 /* 411 * The HID over I2C specification states that if a DEVICE needs time 412 * after the PWR_ON request, it should utilise CLOCK stretching. 413 * However, it has been observered that the Windows driver provides a 414 * 1ms sleep between the PWR_ON and RESET requests. 415 * According to Goodix Windows even waits 60 ms after (other?) 416 * PWR_ON requests. Testing has confirmed that several devices 417 * will not work properly without a delay after a PWR_ON request. 418 */ 419 if (!ret && power_state == I2C_HID_PWR_ON) 420 msleep(60); 421 422 return ret; 423 } 424 425 static int i2c_hid_start_hwreset(struct i2c_hid *ihid) 426 { 427 size_t length = 0; 428 int ret; 429 430 i2c_hid_dbg(ihid, "%s\n", __func__); 431 432 /* 433 * This prevents sending feature reports while the device is 434 * being reset. Otherwise we may lose the reset complete 435 * interrupt. 436 */ 437 lockdep_assert_held(&ihid->reset_lock); 438 439 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 440 if (ret) 441 return ret; 442 443 /* Prepare reset command. Command register goes first. */ 444 *(__le16 *)ihid->cmdbuf = ihid->hdesc.wCommandRegister; 445 length += sizeof(__le16); 446 /* Next is RESET command itself */ 447 length += i2c_hid_encode_command(ihid->cmdbuf + length, 448 I2C_HID_OPCODE_RESET, 0, 0); 449 450 set_bit(I2C_HID_RESET_PENDING, &ihid->flags); 451 452 ret = i2c_hid_xfer(ihid, ihid->cmdbuf, length, NULL, 0); 453 if (ret) { 454 dev_err(&ihid->client->dev, 455 "failed to reset device: %d\n", ret); 456 goto err_clear_reset; 457 } 458 459 return 0; 460 461 err_clear_reset: 462 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 463 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 464 return ret; 465 } 466 467 static int i2c_hid_finish_hwreset(struct i2c_hid *ihid) 468 { 469 int ret = 0; 470 471 i2c_hid_dbg(ihid, "%s: waiting...\n", __func__); 472 473 if (ihid->quirks & I2C_HID_QUIRK_NO_IRQ_AFTER_RESET) { 474 msleep(100); 475 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 476 } else if (!wait_event_timeout(ihid->wait, 477 !test_bit(I2C_HID_RESET_PENDING, &ihid->flags), 478 msecs_to_jiffies(1000))) { 479 dev_warn(&ihid->client->dev, "device did not ack reset within 1000 ms\n"); 480 clear_bit(I2C_HID_RESET_PENDING, &ihid->flags); 481 } 482 i2c_hid_dbg(ihid, "%s: finished.\n", __func__); 483 484 /* At least some SIS devices need this after reset */ 485 if (!(ihid->quirks & I2C_HID_QUIRK_NO_WAKEUP_AFTER_RESET)) 486 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 487 488 return ret; 489 } 490 491 static void i2c_hid_get_input(struct i2c_hid *ihid) 492 { 493 u16 size = le16_to_cpu(ihid->hdesc.wMaxInputLength); 494 u16 ret_size; 495 int ret; 496 497 if (size > ihid->bufsize) 498 size = ihid->bufsize; 499 500 ret = i2c_master_recv(ihid->client, ihid->inbuf, size); 501 if (ret != size) { 502 if (ret < 0) 503 return; 504 505 dev_err(&ihid->client->dev, "%s: got %d data instead of %d\n", 506 __func__, ret, size); 507 return; 508 } 509 510 /* Receiving buffer is properly aligned */ 511 ret_size = le16_to_cpup((__le16 *)ihid->inbuf); 512 if (!ret_size) { 513 /* host or device initiated RESET completed */ 514 if (test_and_clear_bit(I2C_HID_RESET_PENDING, &ihid->flags)) 515 wake_up(&ihid->wait); 516 return; 517 } 518 519 if ((ihid->quirks & I2C_HID_QUIRK_BOGUS_IRQ) && ret_size == 0xffff) { 520 dev_warn_once(&ihid->client->dev, 521 "%s: IRQ triggered but there's no data\n", 522 __func__); 523 return; 524 } 525 526 if (ret_size > size || ret_size < sizeof(__le16)) { 527 if (ihid->quirks & I2C_HID_QUIRK_BAD_INPUT_SIZE) { 528 *(__le16 *)ihid->inbuf = cpu_to_le16(size); 529 ret_size = size; 530 } else { 531 dev_err(&ihid->client->dev, 532 "%s: incomplete report (%d/%d)\n", 533 __func__, size, ret_size); 534 return; 535 } 536 } 537 538 i2c_hid_dbg(ihid, "input: %*ph\n", ret_size, ihid->inbuf); 539 540 if (test_bit(I2C_HID_STARTED, &ihid->flags)) { 541 if (ihid->hid->group != HID_GROUP_RMI) 542 pm_wakeup_event(&ihid->client->dev, 0); 543 544 hid_input_report(ihid->hid, HID_INPUT_REPORT, 545 ihid->inbuf + sizeof(__le16), 546 ret_size - sizeof(__le16), 1); 547 } 548 549 return; 550 } 551 552 static irqreturn_t i2c_hid_irq(int irq, void *dev_id) 553 { 554 struct i2c_hid *ihid = dev_id; 555 556 i2c_hid_get_input(ihid); 557 558 return IRQ_HANDLED; 559 } 560 561 static int i2c_hid_get_report_length(struct hid_report *report) 562 { 563 return ((report->size - 1) >> 3) + 1 + 564 report->device->report_enum[report->type].numbered + 2; 565 } 566 567 /* 568 * Traverse the supplied list of reports and find the longest 569 */ 570 static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type, 571 unsigned int *max) 572 { 573 struct hid_report *report; 574 unsigned int size; 575 576 /* We should not rely on wMaxInputLength, as some devices may set it to 577 * a wrong length. */ 578 list_for_each_entry(report, &hid->report_enum[type].report_list, list) { 579 size = i2c_hid_get_report_length(report); 580 if (*max < size) 581 *max = size; 582 } 583 } 584 585 static void i2c_hid_free_buffers(struct i2c_hid *ihid) 586 { 587 kfree(ihid->inbuf); 588 kfree(ihid->rawbuf); 589 kfree(ihid->cmdbuf); 590 ihid->inbuf = NULL; 591 ihid->rawbuf = NULL; 592 ihid->cmdbuf = NULL; 593 ihid->bufsize = 0; 594 } 595 596 static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size) 597 { 598 /* 599 * The worst case is computed from the set_report command with a 600 * reportID > 15 and the maximum report length. 601 */ 602 int cmd_len = sizeof(__le16) + /* command register */ 603 sizeof(u8) + /* encoded report type/ID */ 604 sizeof(u8) + /* opcode */ 605 sizeof(u8) + /* optional 3rd byte report ID */ 606 sizeof(__le16) + /* data register */ 607 sizeof(__le16) + /* report data size */ 608 sizeof(u8) + /* report ID if numbered report */ 609 report_size; 610 611 ihid->inbuf = kzalloc(report_size, GFP_KERNEL); 612 ihid->rawbuf = kzalloc(report_size, GFP_KERNEL); 613 ihid->cmdbuf = kzalloc(cmd_len, GFP_KERNEL); 614 615 if (!ihid->inbuf || !ihid->rawbuf || !ihid->cmdbuf) { 616 i2c_hid_free_buffers(ihid); 617 return -ENOMEM; 618 } 619 620 ihid->bufsize = report_size; 621 622 return 0; 623 } 624 625 static int i2c_hid_get_raw_report(struct hid_device *hid, 626 u8 report_type, u8 report_id, 627 u8 *buf, size_t count) 628 { 629 struct i2c_client *client = hid->driver_data; 630 struct i2c_hid *ihid = i2c_get_clientdata(client); 631 int ret_count; 632 633 if (report_type == HID_OUTPUT_REPORT) 634 return -EINVAL; 635 636 /* 637 * In case of unnumbered reports the response from the device will 638 * not have the report ID that the upper layers expect, so we need 639 * to stash it the buffer ourselves and adjust the data size. 640 */ 641 if (!report_id) { 642 buf[0] = 0; 643 buf++; 644 count--; 645 } 646 647 ret_count = i2c_hid_get_report(ihid, 648 report_type == HID_FEATURE_REPORT ? 0x03 : 0x01, 649 report_id, buf, count); 650 651 if (ret_count > 0 && !report_id) 652 ret_count++; 653 654 return ret_count; 655 } 656 657 static int i2c_hid_output_raw_report(struct hid_device *hid, u8 report_type, 658 const u8 *buf, size_t count, bool do_set) 659 { 660 struct i2c_client *client = hid->driver_data; 661 struct i2c_hid *ihid = i2c_get_clientdata(client); 662 int report_id = buf[0]; 663 int ret; 664 665 if (report_type == HID_INPUT_REPORT) 666 return -EINVAL; 667 668 mutex_lock(&ihid->reset_lock); 669 670 /* 671 * Note that both numbered and unnumbered reports passed here 672 * are supposed to have report ID stored in the 1st byte of the 673 * buffer, so we strip it off unconditionally before passing payload 674 * to i2c_hid_set_or_send_report which takes care of encoding 675 * everything properly. 676 */ 677 ret = i2c_hid_set_or_send_report(ihid, 678 report_type == HID_FEATURE_REPORT ? 0x03 : 0x02, 679 report_id, buf + 1, count - 1, do_set); 680 681 if (ret >= 0) 682 ret++; /* add report_id to the number of transferred bytes */ 683 684 mutex_unlock(&ihid->reset_lock); 685 686 return ret; 687 } 688 689 static int i2c_hid_output_report(struct hid_device *hid, u8 *buf, size_t count) 690 { 691 return i2c_hid_output_raw_report(hid, HID_OUTPUT_REPORT, buf, count, 692 false); 693 } 694 695 static int i2c_hid_raw_request(struct hid_device *hid, unsigned char reportnum, 696 __u8 *buf, size_t len, unsigned char rtype, 697 int reqtype) 698 { 699 switch (reqtype) { 700 case HID_REQ_GET_REPORT: 701 return i2c_hid_get_raw_report(hid, rtype, reportnum, buf, len); 702 case HID_REQ_SET_REPORT: 703 if (buf[0] != reportnum) 704 return -EINVAL; 705 return i2c_hid_output_raw_report(hid, rtype, buf, len, true); 706 default: 707 return -EIO; 708 } 709 } 710 711 static int i2c_hid_parse(struct hid_device *hid) 712 { 713 struct i2c_client *client = hid->driver_data; 714 struct i2c_hid *ihid = i2c_get_clientdata(client); 715 struct i2c_hid_desc *hdesc = &ihid->hdesc; 716 char *rdesc = NULL, *use_override = NULL; 717 unsigned int rsize; 718 int ret; 719 int tries = 3; 720 721 i2c_hid_dbg(ihid, "entering %s\n", __func__); 722 723 rsize = le16_to_cpu(hdesc->wReportDescLength); 724 if (!rsize || rsize > HID_MAX_DESCRIPTOR_SIZE) { 725 dbg_hid("weird size of report descriptor (%u)\n", rsize); 726 return -EINVAL; 727 } 728 729 mutex_lock(&ihid->reset_lock); 730 do { 731 ret = i2c_hid_start_hwreset(ihid); 732 if (ret == 0) 733 ret = i2c_hid_finish_hwreset(ihid); 734 else 735 msleep(1000); 736 } while (tries-- > 0 && ret); 737 mutex_unlock(&ihid->reset_lock); 738 739 if (ret) 740 return ret; 741 742 use_override = i2c_hid_get_dmi_hid_report_desc_override(client->name, 743 &rsize); 744 745 if (use_override) { 746 rdesc = use_override; 747 i2c_hid_dbg(ihid, "Using a HID report descriptor override\n"); 748 } else { 749 rdesc = kzalloc(rsize, GFP_KERNEL); 750 if (!rdesc) 751 return -ENOMEM; 752 753 i2c_hid_dbg(ihid, "asking HID report descriptor\n"); 754 755 ret = i2c_hid_read_register(ihid, 756 ihid->hdesc.wReportDescRegister, 757 rdesc, rsize); 758 if (ret) { 759 hid_err(hid, "reading report descriptor failed\n"); 760 goto out; 761 } 762 } 763 764 i2c_hid_dbg(ihid, "Report Descriptor: %*ph\n", rsize, rdesc); 765 766 ret = hid_parse_report(hid, rdesc, rsize); 767 if (ret) 768 dbg_hid("parsing report descriptor failed\n"); 769 770 out: 771 if (!use_override) 772 kfree(rdesc); 773 774 return ret; 775 } 776 777 static int i2c_hid_start(struct hid_device *hid) 778 { 779 struct i2c_client *client = hid->driver_data; 780 struct i2c_hid *ihid = i2c_get_clientdata(client); 781 int ret; 782 unsigned int bufsize = HID_MIN_BUFFER_SIZE; 783 784 i2c_hid_find_max_report(hid, HID_INPUT_REPORT, &bufsize); 785 i2c_hid_find_max_report(hid, HID_OUTPUT_REPORT, &bufsize); 786 i2c_hid_find_max_report(hid, HID_FEATURE_REPORT, &bufsize); 787 788 if (bufsize > ihid->bufsize) { 789 disable_irq(client->irq); 790 i2c_hid_free_buffers(ihid); 791 792 ret = i2c_hid_alloc_buffers(ihid, bufsize); 793 enable_irq(client->irq); 794 795 if (ret) 796 return ret; 797 } 798 799 return 0; 800 } 801 802 static void i2c_hid_stop(struct hid_device *hid) 803 { 804 hid->claimed = 0; 805 } 806 807 static int i2c_hid_open(struct hid_device *hid) 808 { 809 struct i2c_client *client = hid->driver_data; 810 struct i2c_hid *ihid = i2c_get_clientdata(client); 811 812 set_bit(I2C_HID_STARTED, &ihid->flags); 813 return 0; 814 } 815 816 static void i2c_hid_close(struct hid_device *hid) 817 { 818 struct i2c_client *client = hid->driver_data; 819 struct i2c_hid *ihid = i2c_get_clientdata(client); 820 821 clear_bit(I2C_HID_STARTED, &ihid->flags); 822 } 823 824 static const struct hid_ll_driver i2c_hid_ll_driver = { 825 .parse = i2c_hid_parse, 826 .start = i2c_hid_start, 827 .stop = i2c_hid_stop, 828 .open = i2c_hid_open, 829 .close = i2c_hid_close, 830 .output_report = i2c_hid_output_report, 831 .raw_request = i2c_hid_raw_request, 832 }; 833 834 static int i2c_hid_init_irq(struct i2c_client *client) 835 { 836 struct i2c_hid *ihid = i2c_get_clientdata(client); 837 unsigned long irqflags = 0; 838 int ret; 839 840 i2c_hid_dbg(ihid, "Requesting IRQ: %d\n", client->irq); 841 842 if (!irq_get_trigger_type(client->irq)) 843 irqflags = IRQF_TRIGGER_LOW; 844 845 ret = request_threaded_irq(client->irq, NULL, i2c_hid_irq, 846 irqflags | IRQF_ONESHOT | IRQF_NO_AUTOEN, 847 client->name, ihid); 848 if (ret < 0) { 849 dev_warn(&client->dev, 850 "Could not register for %s interrupt, irq = %d," 851 " ret = %d\n", 852 client->name, client->irq, ret); 853 854 return ret; 855 } 856 857 return 0; 858 } 859 860 static int i2c_hid_fetch_hid_descriptor(struct i2c_hid *ihid) 861 { 862 struct i2c_client *client = ihid->client; 863 struct i2c_hid_desc *hdesc = &ihid->hdesc; 864 unsigned int dsize; 865 int error; 866 867 /* i2c hid fetch using a fixed descriptor size (30 bytes) */ 868 if (i2c_hid_get_dmi_i2c_hid_desc_override(client->name)) { 869 i2c_hid_dbg(ihid, "Using a HID descriptor override\n"); 870 ihid->hdesc = 871 *i2c_hid_get_dmi_i2c_hid_desc_override(client->name); 872 } else { 873 i2c_hid_dbg(ihid, "Fetching the HID descriptor\n"); 874 error = i2c_hid_read_register(ihid, 875 ihid->wHIDDescRegister, 876 &ihid->hdesc, 877 sizeof(ihid->hdesc)); 878 if (error) { 879 dev_err(&ihid->client->dev, 880 "failed to fetch HID descriptor: %d\n", 881 error); 882 return -ENODEV; 883 } 884 } 885 886 /* Validate the length of HID descriptor, the 4 first bytes: 887 * bytes 0-1 -> length 888 * bytes 2-3 -> bcdVersion (has to be 1.00) */ 889 /* check bcdVersion == 1.0 */ 890 if (le16_to_cpu(hdesc->bcdVersion) != 0x0100) { 891 dev_err(&ihid->client->dev, 892 "unexpected HID descriptor bcdVersion (0x%04hx)\n", 893 le16_to_cpu(hdesc->bcdVersion)); 894 return -ENODEV; 895 } 896 897 /* Descriptor length should be 30 bytes as per the specification */ 898 dsize = le16_to_cpu(hdesc->wHIDDescLength); 899 if (dsize != sizeof(struct i2c_hid_desc)) { 900 dev_err(&ihid->client->dev, 901 "weird size of HID descriptor (%u)\n", dsize); 902 return -ENODEV; 903 } 904 i2c_hid_dbg(ihid, "HID Descriptor: %*ph\n", dsize, &ihid->hdesc); 905 return 0; 906 } 907 908 static int i2c_hid_core_power_up(struct i2c_hid *ihid) 909 { 910 if (!ihid->ops->power_up) 911 return 0; 912 913 return ihid->ops->power_up(ihid->ops); 914 } 915 916 static void i2c_hid_core_power_down(struct i2c_hid *ihid) 917 { 918 if (!ihid->ops->power_down) 919 return; 920 921 ihid->ops->power_down(ihid->ops); 922 } 923 924 static void i2c_hid_core_shutdown_tail(struct i2c_hid *ihid) 925 { 926 if (!ihid->ops->shutdown_tail) 927 return; 928 929 ihid->ops->shutdown_tail(ihid->ops); 930 } 931 932 static int i2c_hid_core_suspend(struct i2c_hid *ihid, bool force_poweroff) 933 { 934 struct i2c_client *client = ihid->client; 935 struct hid_device *hid = ihid->hid; 936 int ret; 937 938 ret = hid_driver_suspend(hid, PMSG_SUSPEND); 939 if (ret < 0) 940 return ret; 941 942 /* Save some power */ 943 if (!(ihid->quirks & I2C_HID_QUIRK_NO_SLEEP_ON_SUSPEND)) 944 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 945 946 disable_irq(client->irq); 947 948 if (force_poweroff || !device_may_wakeup(&client->dev)) 949 i2c_hid_core_power_down(ihid); 950 951 return 0; 952 } 953 954 static int i2c_hid_core_resume(struct i2c_hid *ihid) 955 { 956 struct i2c_client *client = ihid->client; 957 struct hid_device *hid = ihid->hid; 958 int ret; 959 960 if (!device_may_wakeup(&client->dev)) 961 i2c_hid_core_power_up(ihid); 962 963 enable_irq(client->irq); 964 965 /* Make sure the device is awake on the bus */ 966 ret = i2c_hid_probe_address(ihid); 967 if (ret < 0) { 968 dev_err(&client->dev, "nothing at address after resume: %d\n", 969 ret); 970 return -ENXIO; 971 } 972 973 /* Instead of resetting device, simply powers the device on. This 974 * solves "incomplete reports" on Raydium devices 2386:3118 and 975 * 2386:4B33 and fixes various SIS touchscreens no longer sending 976 * data after a suspend/resume. 977 * 978 * However some ALPS touchpads generate IRQ storm without reset, so 979 * let's still reset them here. 980 */ 981 if (ihid->quirks & I2C_HID_QUIRK_RESET_ON_RESUME) { 982 mutex_lock(&ihid->reset_lock); 983 ret = i2c_hid_start_hwreset(ihid); 984 if (ret == 0) 985 ret = i2c_hid_finish_hwreset(ihid); 986 mutex_unlock(&ihid->reset_lock); 987 } else { 988 ret = i2c_hid_set_power(ihid, I2C_HID_PWR_ON); 989 } 990 991 if (ret) 992 return ret; 993 994 return hid_driver_reset_resume(hid); 995 } 996 997 /* 998 * Check that the device exists and parse the HID descriptor. 999 */ 1000 static int __i2c_hid_core_probe(struct i2c_hid *ihid) 1001 { 1002 struct i2c_client *client = ihid->client; 1003 struct hid_device *hid = ihid->hid; 1004 int ret; 1005 1006 ret = i2c_hid_probe_address(ihid); 1007 if (ret < 0) { 1008 i2c_hid_dbg(ihid, "nothing at this address: %d\n", ret); 1009 return -ENXIO; 1010 } 1011 1012 ret = i2c_hid_fetch_hid_descriptor(ihid); 1013 if (ret < 0) { 1014 dev_err(&client->dev, 1015 "Failed to fetch the HID Descriptor\n"); 1016 return ret; 1017 } 1018 1019 hid->version = le16_to_cpu(ihid->hdesc.bcdVersion); 1020 hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID); 1021 hid->product = le16_to_cpu(ihid->hdesc.wProductID); 1022 1023 hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor, 1024 hid->product); 1025 1026 snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X", 1027 client->name, (u16)hid->vendor, (u16)hid->product); 1028 strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys)); 1029 1030 ihid->quirks = i2c_hid_lookup_quirk(hid->vendor, hid->product); 1031 1032 return 0; 1033 } 1034 1035 static int i2c_hid_core_register_hid(struct i2c_hid *ihid) 1036 { 1037 struct i2c_client *client = ihid->client; 1038 struct hid_device *hid = ihid->hid; 1039 int ret; 1040 1041 enable_irq(client->irq); 1042 1043 ret = hid_add_device(hid); 1044 if (ret) { 1045 if (ret != -ENODEV) 1046 hid_err(client, "can't add hid device: %d\n", ret); 1047 disable_irq(client->irq); 1048 return ret; 1049 } 1050 1051 return 0; 1052 } 1053 1054 static int i2c_hid_core_probe_panel_follower(struct i2c_hid *ihid) 1055 { 1056 int ret; 1057 1058 ret = i2c_hid_core_power_up(ihid); 1059 if (ret) 1060 return ret; 1061 1062 ret = __i2c_hid_core_probe(ihid); 1063 if (ret) 1064 goto err_power_down; 1065 1066 ret = i2c_hid_core_register_hid(ihid); 1067 if (ret) 1068 goto err_power_down; 1069 1070 return 0; 1071 1072 err_power_down: 1073 i2c_hid_core_power_down(ihid); 1074 1075 return ret; 1076 } 1077 1078 static void ihid_core_panel_prepare_work(struct work_struct *work) 1079 { 1080 struct i2c_hid *ihid = container_of(work, struct i2c_hid, 1081 panel_follower_prepare_work); 1082 struct hid_device *hid = ihid->hid; 1083 int ret; 1084 1085 /* 1086 * hid->version is set on the first power up. If it's still zero then 1087 * this is the first power on so we should perform initial power up 1088 * steps. 1089 */ 1090 if (!hid->version) 1091 ret = i2c_hid_core_probe_panel_follower(ihid); 1092 else 1093 ret = i2c_hid_core_resume(ihid); 1094 1095 if (ret) 1096 dev_warn(&ihid->client->dev, "Power on failed: %d\n", ret); 1097 else 1098 WRITE_ONCE(ihid->prepare_work_finished, true); 1099 1100 /* 1101 * The work APIs provide a number of memory ordering guarantees 1102 * including one that says that memory writes before schedule_work() 1103 * are always visible to the work function, but they don't appear to 1104 * guarantee that a write that happened in the work is visible after 1105 * cancel_work_sync(). We'll add a write memory barrier here to match 1106 * with i2c_hid_core_panel_unpreparing() to ensure that our write to 1107 * prepare_work_finished is visible there. 1108 */ 1109 smp_wmb(); 1110 } 1111 1112 static int i2c_hid_core_panel_prepared(struct drm_panel_follower *follower) 1113 { 1114 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1115 1116 /* 1117 * Powering on a touchscreen can be a slow process. Queue the work to 1118 * the system workqueue so we don't block the panel's power up. 1119 */ 1120 WRITE_ONCE(ihid->prepare_work_finished, false); 1121 schedule_work(&ihid->panel_follower_prepare_work); 1122 1123 return 0; 1124 } 1125 1126 static int i2c_hid_core_panel_unpreparing(struct drm_panel_follower *follower) 1127 { 1128 struct i2c_hid *ihid = container_of(follower, struct i2c_hid, panel_follower); 1129 1130 cancel_work_sync(&ihid->panel_follower_prepare_work); 1131 1132 /* Match with ihid_core_panel_prepare_work() */ 1133 smp_rmb(); 1134 if (!READ_ONCE(ihid->prepare_work_finished)) 1135 return 0; 1136 1137 return i2c_hid_core_suspend(ihid, true); 1138 } 1139 1140 static const struct drm_panel_follower_funcs i2c_hid_core_panel_follower_funcs = { 1141 .panel_prepared = i2c_hid_core_panel_prepared, 1142 .panel_unpreparing = i2c_hid_core_panel_unpreparing, 1143 }; 1144 1145 static int i2c_hid_core_register_panel_follower(struct i2c_hid *ihid) 1146 { 1147 struct device *dev = &ihid->client->dev; 1148 int ret; 1149 1150 ihid->panel_follower.funcs = &i2c_hid_core_panel_follower_funcs; 1151 1152 /* 1153 * If we're not in control of our own power up/power down then we can't 1154 * do the logic to manage wakeups. Give a warning if a user thought 1155 * that was possible then force the capability off. 1156 */ 1157 if (device_can_wakeup(dev)) { 1158 dev_warn(dev, "Can't wakeup if following panel\n"); 1159 device_set_wakeup_capable(dev, false); 1160 } 1161 1162 ret = drm_panel_add_follower(dev, &ihid->panel_follower); 1163 if (ret) 1164 return ret; 1165 1166 return 0; 1167 } 1168 1169 int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops, 1170 u16 hid_descriptor_address, u32 quirks) 1171 { 1172 int ret; 1173 struct i2c_hid *ihid; 1174 struct hid_device *hid; 1175 1176 dbg_hid("HID probe called for i2c 0x%02x\n", client->addr); 1177 1178 if (!client->irq) { 1179 dev_err(&client->dev, 1180 "HID over i2c has not been provided an Int IRQ\n"); 1181 return -EINVAL; 1182 } 1183 1184 if (client->irq < 0) { 1185 if (client->irq != -EPROBE_DEFER) 1186 dev_err(&client->dev, 1187 "HID over i2c doesn't have a valid IRQ\n"); 1188 return client->irq; 1189 } 1190 1191 ihid = devm_kzalloc(&client->dev, sizeof(*ihid), GFP_KERNEL); 1192 if (!ihid) 1193 return -ENOMEM; 1194 1195 i2c_set_clientdata(client, ihid); 1196 1197 ihid->ops = ops; 1198 ihid->client = client; 1199 ihid->wHIDDescRegister = cpu_to_le16(hid_descriptor_address); 1200 ihid->is_panel_follower = drm_is_panel_follower(&client->dev); 1201 1202 init_waitqueue_head(&ihid->wait); 1203 mutex_init(&ihid->reset_lock); 1204 INIT_WORK(&ihid->panel_follower_prepare_work, ihid_core_panel_prepare_work); 1205 1206 /* we need to allocate the command buffer without knowing the maximum 1207 * size of the reports. Let's use HID_MIN_BUFFER_SIZE, then we do the 1208 * real computation later. */ 1209 ret = i2c_hid_alloc_buffers(ihid, HID_MIN_BUFFER_SIZE); 1210 if (ret < 0) 1211 return ret; 1212 device_enable_async_suspend(&client->dev); 1213 1214 hid = hid_allocate_device(); 1215 if (IS_ERR(hid)) { 1216 ret = PTR_ERR(hid); 1217 goto err_free_buffers; 1218 } 1219 1220 ihid->hid = hid; 1221 1222 hid->driver_data = client; 1223 hid->ll_driver = &i2c_hid_ll_driver; 1224 hid->dev.parent = &client->dev; 1225 hid->bus = BUS_I2C; 1226 hid->initial_quirks = quirks; 1227 1228 /* Power on and probe unless device is a panel follower. */ 1229 if (!ihid->is_panel_follower) { 1230 ret = i2c_hid_core_power_up(ihid); 1231 if (ret < 0) 1232 goto err_destroy_device; 1233 1234 ret = __i2c_hid_core_probe(ihid); 1235 if (ret < 0) 1236 goto err_power_down; 1237 } 1238 1239 ret = i2c_hid_init_irq(client); 1240 if (ret < 0) 1241 goto err_power_down; 1242 1243 /* 1244 * If we're a panel follower, we'll register when the panel turns on; 1245 * otherwise we do it right away. 1246 */ 1247 if (ihid->is_panel_follower) 1248 ret = i2c_hid_core_register_panel_follower(ihid); 1249 else 1250 ret = i2c_hid_core_register_hid(ihid); 1251 if (ret) 1252 goto err_free_irq; 1253 1254 return 0; 1255 1256 err_free_irq: 1257 free_irq(client->irq, ihid); 1258 err_power_down: 1259 if (!ihid->is_panel_follower) 1260 i2c_hid_core_power_down(ihid); 1261 err_destroy_device: 1262 hid_destroy_device(hid); 1263 err_free_buffers: 1264 i2c_hid_free_buffers(ihid); 1265 1266 return ret; 1267 } 1268 EXPORT_SYMBOL_GPL(i2c_hid_core_probe); 1269 1270 void i2c_hid_core_remove(struct i2c_client *client) 1271 { 1272 struct i2c_hid *ihid = i2c_get_clientdata(client); 1273 struct hid_device *hid; 1274 1275 /* 1276 * If we're a follower, the act of unfollowing will cause us to be 1277 * powered down. Otherwise we need to manually do it. 1278 */ 1279 if (ihid->is_panel_follower) 1280 drm_panel_remove_follower(&ihid->panel_follower); 1281 else 1282 i2c_hid_core_suspend(ihid, true); 1283 1284 hid = ihid->hid; 1285 hid_destroy_device(hid); 1286 1287 free_irq(client->irq, ihid); 1288 1289 if (ihid->bufsize) 1290 i2c_hid_free_buffers(ihid); 1291 } 1292 EXPORT_SYMBOL_GPL(i2c_hid_core_remove); 1293 1294 void i2c_hid_core_shutdown(struct i2c_client *client) 1295 { 1296 struct i2c_hid *ihid = i2c_get_clientdata(client); 1297 1298 i2c_hid_set_power(ihid, I2C_HID_PWR_SLEEP); 1299 free_irq(client->irq, ihid); 1300 1301 i2c_hid_core_shutdown_tail(ihid); 1302 } 1303 EXPORT_SYMBOL_GPL(i2c_hid_core_shutdown); 1304 1305 static int i2c_hid_core_pm_suspend(struct device *dev) 1306 { 1307 struct i2c_client *client = to_i2c_client(dev); 1308 struct i2c_hid *ihid = i2c_get_clientdata(client); 1309 1310 if (ihid->is_panel_follower) 1311 return 0; 1312 1313 return i2c_hid_core_suspend(ihid, false); 1314 } 1315 1316 static int i2c_hid_core_pm_resume(struct device *dev) 1317 { 1318 struct i2c_client *client = to_i2c_client(dev); 1319 struct i2c_hid *ihid = i2c_get_clientdata(client); 1320 1321 if (ihid->is_panel_follower) 1322 return 0; 1323 1324 return i2c_hid_core_resume(ihid); 1325 } 1326 1327 const struct dev_pm_ops i2c_hid_core_pm = { 1328 SYSTEM_SLEEP_PM_OPS(i2c_hid_core_pm_suspend, i2c_hid_core_pm_resume) 1329 }; 1330 EXPORT_SYMBOL_GPL(i2c_hid_core_pm); 1331 1332 MODULE_DESCRIPTION("HID over I2C core driver"); 1333 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>"); 1334 MODULE_LICENSE("GPL"); 1335