1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2020 Samsung Electronics Co., Ltd. 4 * Copyright 2020 Google LLC. 5 * Copyright 2024 Linaro Ltd. 6 */ 7 8 #include <linux/bitfield.h> 9 #include <linux/bitmap.h> 10 #include <linux/bits.h> 11 #include <linux/cleanup.h> 12 #include <linux/container_of.h> 13 #include <linux/delay.h> 14 #include <linux/device.h> 15 #include <linux/firmware/samsung/exynos-acpm-protocol.h> 16 #include <linux/io.h> 17 #include <linux/iopoll.h> 18 #include <linux/mailbox/exynos-message.h> 19 #include <linux/mailbox_client.h> 20 #include <linux/module.h> 21 #include <linux/mutex.h> 22 #include <linux/math.h> 23 #include <linux/of.h> 24 #include <linux/of_address.h> 25 #include <linux/of_platform.h> 26 #include <linux/platform_device.h> 27 #include <linux/slab.h> 28 #include <linux/types.h> 29 30 #include "exynos-acpm.h" 31 #include "exynos-acpm-pmic.h" 32 33 #define ACPM_PROTOCOL_SEQNUM GENMASK(21, 16) 34 35 /* The unit of counter is 20 us. 5000 * 20 = 100 ms */ 36 #define ACPM_POLL_TIMEOUT 5000 37 #define ACPM_TX_TIMEOUT_US 500000 38 39 #define ACPM_GS101_INITDATA_BASE 0xa000 40 41 /** 42 * struct acpm_shmem - shared memory configuration information. 43 * @reserved: unused fields. 44 * @chans: offset to array of struct acpm_chan_shmem. 45 * @reserved1: unused fields. 46 * @num_chans: number of channels. 47 */ 48 struct acpm_shmem { 49 u32 reserved[2]; 50 u32 chans; 51 u32 reserved1[3]; 52 u32 num_chans; 53 }; 54 55 /** 56 * struct acpm_chan_shmem - descriptor of a shared memory channel. 57 * 58 * @id: channel ID. 59 * @reserved: unused fields. 60 * @rx_rear: rear pointer of APM RX queue (TX for AP). 61 * @rx_front: front pointer of APM RX queue (TX for AP). 62 * @rx_base: base address of APM RX queue (TX for AP). 63 * @reserved1: unused fields. 64 * @tx_rear: rear pointer of APM TX queue (RX for AP). 65 * @tx_front: front pointer of APM TX queue (RX for AP). 66 * @tx_base: base address of APM TX queue (RX for AP). 67 * @qlen: queue length. Applies to both TX/RX queues. 68 * @mlen: message length. Applies to both TX/RX queues. 69 * @reserved2: unused fields. 70 * @poll_completion: true when the channel works on polling. 71 */ 72 struct acpm_chan_shmem { 73 u32 id; 74 u32 reserved[3]; 75 u32 rx_rear; 76 u32 rx_front; 77 u32 rx_base; 78 u32 reserved1[3]; 79 u32 tx_rear; 80 u32 tx_front; 81 u32 tx_base; 82 u32 qlen; 83 u32 mlen; 84 u32 reserved2[2]; 85 u32 poll_completion; 86 }; 87 88 /** 89 * struct acpm_queue - exynos acpm queue. 90 * 91 * @rear: rear address of the queue. 92 * @front: front address of the queue. 93 * @base: base address of the queue. 94 */ 95 struct acpm_queue { 96 void __iomem *rear; 97 void __iomem *front; 98 void __iomem *base; 99 }; 100 101 /** 102 * struct acpm_rx_data - RX queue data. 103 * 104 * @cmd: pointer to where the data shall be saved. 105 * @n_cmd: number of 32-bit commands. 106 * @response: true if the client expects the RX data. 107 */ 108 struct acpm_rx_data { 109 u32 *cmd; 110 size_t n_cmd; 111 bool response; 112 }; 113 114 #define ACPM_SEQNUM_MAX 64 115 116 /** 117 * struct acpm_chan - driver internal representation of a channel. 118 * @cl: mailbox client. 119 * @chan: mailbox channel. 120 * @acpm: pointer to driver private data. 121 * @tx: TX queue. The enqueue is done by the host. 122 * - front index is written by the host. 123 * - rear index is written by the firmware. 124 * 125 * @rx: RX queue. The enqueue is done by the firmware. 126 * - front index is written by the firmware. 127 * - rear index is written by the host. 128 * @tx_lock: protects TX queue. 129 * @rx_lock: protects RX queue. 130 * @qlen: queue length. Applies to both TX/RX queues. 131 * @mlen: message length. Applies to both TX/RX queues. 132 * @seqnum: sequence number of the last message enqueued on TX queue. 133 * @id: channel ID. 134 * @poll_completion: indicates if the transfer needs to be polled for 135 * completion or interrupt mode is used. 136 * @bitmap_seqnum: bitmap that tracks the messages on the TX/RX queues. 137 * @rx_data: internal buffer used to drain the RX queue. 138 */ 139 struct acpm_chan { 140 struct mbox_client cl; 141 struct mbox_chan *chan; 142 struct acpm_info *acpm; 143 struct acpm_queue tx; 144 struct acpm_queue rx; 145 struct mutex tx_lock; 146 struct mutex rx_lock; 147 148 unsigned int qlen; 149 unsigned int mlen; 150 u8 seqnum; 151 u8 id; 152 bool poll_completion; 153 154 DECLARE_BITMAP(bitmap_seqnum, ACPM_SEQNUM_MAX - 1); 155 struct acpm_rx_data rx_data[ACPM_SEQNUM_MAX]; 156 }; 157 158 /** 159 * struct acpm_info - driver's private data. 160 * @shmem: pointer to the SRAM configuration data. 161 * @sram_base: base address of SRAM. 162 * @chans: pointer to the ACPM channel parameters retrieved from SRAM. 163 * @dev: pointer to the exynos-acpm device. 164 * @handle: instance of acpm_handle to send to clients. 165 * @num_chans: number of channels available for this controller. 166 */ 167 struct acpm_info { 168 struct acpm_shmem __iomem *shmem; 169 void __iomem *sram_base; 170 struct acpm_chan *chans; 171 struct device *dev; 172 struct acpm_handle handle; 173 u32 num_chans; 174 }; 175 176 /** 177 * struct acpm_match_data - of_device_id data. 178 * @initdata_base: offset in SRAM where the channels configuration resides. 179 */ 180 struct acpm_match_data { 181 loff_t initdata_base; 182 }; 183 184 #define client_to_acpm_chan(c) container_of(c, struct acpm_chan, cl) 185 #define handle_to_acpm_info(h) container_of(h, struct acpm_info, handle) 186 187 /** 188 * acpm_get_rx() - get response from RX queue. 189 * @achan: ACPM channel info. 190 * @xfer: reference to the transfer to get response for. 191 * 192 * Return: 0 on success, -errno otherwise. 193 */ 194 static int acpm_get_rx(struct acpm_chan *achan, const struct acpm_xfer *xfer) 195 { 196 u32 rx_front, rx_seqnum, tx_seqnum, seqnum; 197 const void __iomem *base, *addr; 198 struct acpm_rx_data *rx_data; 199 u32 i, val, mlen; 200 bool rx_set = false; 201 202 guard(mutex)(&achan->rx_lock); 203 204 rx_front = readl(achan->rx.front); 205 i = readl(achan->rx.rear); 206 207 /* Bail out if RX is empty. */ 208 if (i == rx_front) 209 return 0; 210 211 base = achan->rx.base; 212 mlen = achan->mlen; 213 214 tx_seqnum = FIELD_GET(ACPM_PROTOCOL_SEQNUM, xfer->txd[0]); 215 216 /* Drain RX queue. */ 217 do { 218 /* Read RX seqnum. */ 219 addr = base + mlen * i; 220 val = readl(addr); 221 222 rx_seqnum = FIELD_GET(ACPM_PROTOCOL_SEQNUM, val); 223 if (!rx_seqnum) 224 return -EIO; 225 /* 226 * mssg seqnum starts with value 1, whereas the driver considers 227 * the first mssg at index 0. 228 */ 229 seqnum = rx_seqnum - 1; 230 rx_data = &achan->rx_data[seqnum]; 231 232 if (rx_data->response) { 233 if (rx_seqnum == tx_seqnum) { 234 __ioread32_copy(xfer->rxd, addr, 235 xfer->rxlen / 4); 236 rx_set = true; 237 clear_bit(seqnum, achan->bitmap_seqnum); 238 } else { 239 /* 240 * The RX data corresponds to another request. 241 * Save the data to drain the queue, but don't 242 * clear yet the bitmap. It will be cleared 243 * after the response is copied to the request. 244 */ 245 __ioread32_copy(rx_data->cmd, addr, 246 xfer->rxlen / 4); 247 } 248 } else { 249 clear_bit(seqnum, achan->bitmap_seqnum); 250 } 251 252 i = (i + 1) % achan->qlen; 253 } while (i != rx_front); 254 255 /* We saved all responses, mark RX empty. */ 256 writel(rx_front, achan->rx.rear); 257 258 /* 259 * If the response was not in this iteration of the queue, check if the 260 * RX data was previously saved. 261 */ 262 rx_data = &achan->rx_data[tx_seqnum - 1]; 263 if (!rx_set && rx_data->response) { 264 rx_seqnum = FIELD_GET(ACPM_PROTOCOL_SEQNUM, 265 rx_data->cmd[0]); 266 267 if (rx_seqnum == tx_seqnum) { 268 memcpy(xfer->rxd, rx_data->cmd, xfer->rxlen); 269 clear_bit(rx_seqnum - 1, achan->bitmap_seqnum); 270 } 271 } 272 273 return 0; 274 } 275 276 /** 277 * acpm_dequeue_by_polling() - RX dequeue by polling. 278 * @achan: ACPM channel info. 279 * @xfer: reference to the transfer being waited for. 280 * 281 * Return: 0 on success, -errno otherwise. 282 */ 283 static int acpm_dequeue_by_polling(struct acpm_chan *achan, 284 const struct acpm_xfer *xfer) 285 { 286 struct device *dev = achan->acpm->dev; 287 unsigned int cnt_20us = 0; 288 u32 seqnum; 289 int ret; 290 291 seqnum = FIELD_GET(ACPM_PROTOCOL_SEQNUM, xfer->txd[0]); 292 293 do { 294 ret = acpm_get_rx(achan, xfer); 295 if (ret) 296 return ret; 297 298 if (!test_bit(seqnum - 1, achan->bitmap_seqnum)) 299 return 0; 300 301 /* Determined experimentally. */ 302 usleep_range(20, 30); 303 cnt_20us++; 304 } while (cnt_20us < ACPM_POLL_TIMEOUT); 305 306 dev_err(dev, "Timeout! ch:%u s:%u bitmap:%lx, cnt_20us = %d.\n", 307 achan->id, seqnum, achan->bitmap_seqnum[0], cnt_20us); 308 309 return -ETIME; 310 } 311 312 /** 313 * acpm_wait_for_queue_slots() - wait for queue slots. 314 * 315 * @achan: ACPM channel info. 316 * @next_tx_front: next front index of the TX queue. 317 * 318 * Return: 0 on success, -errno otherwise. 319 */ 320 static int acpm_wait_for_queue_slots(struct acpm_chan *achan, u32 next_tx_front) 321 { 322 u32 val, ret; 323 324 /* 325 * Wait for RX front to keep up with TX front. Make sure there's at 326 * least one element between them. 327 */ 328 ret = readl_poll_timeout(achan->rx.front, val, next_tx_front != val, 0, 329 ACPM_TX_TIMEOUT_US); 330 if (ret) { 331 dev_err(achan->acpm->dev, "RX front can not keep up with TX front.\n"); 332 return ret; 333 } 334 335 ret = readl_poll_timeout(achan->tx.rear, val, next_tx_front != val, 0, 336 ACPM_TX_TIMEOUT_US); 337 if (ret) 338 dev_err(achan->acpm->dev, "TX queue is full.\n"); 339 340 return ret; 341 } 342 343 /** 344 * acpm_prepare_xfer() - prepare a transfer before writing the message to the 345 * TX queue. 346 * @achan: ACPM channel info. 347 * @xfer: reference to the transfer being prepared. 348 */ 349 static void acpm_prepare_xfer(struct acpm_chan *achan, 350 const struct acpm_xfer *xfer) 351 { 352 struct acpm_rx_data *rx_data; 353 u32 *txd = (u32 *)xfer->txd; 354 355 /* Prevent chan->seqnum from being re-used */ 356 do { 357 if (++achan->seqnum == ACPM_SEQNUM_MAX) 358 achan->seqnum = 1; 359 } while (test_bit(achan->seqnum - 1, achan->bitmap_seqnum)); 360 361 txd[0] |= FIELD_PREP(ACPM_PROTOCOL_SEQNUM, achan->seqnum); 362 363 /* Clear data for upcoming responses */ 364 rx_data = &achan->rx_data[achan->seqnum - 1]; 365 memset(rx_data->cmd, 0, sizeof(*rx_data->cmd) * rx_data->n_cmd); 366 if (xfer->rxd) 367 rx_data->response = true; 368 369 /* Flag the index based on seqnum. (seqnum: 1~63, bitmap: 0~62) */ 370 set_bit(achan->seqnum - 1, achan->bitmap_seqnum); 371 } 372 373 /** 374 * acpm_wait_for_message_response - an helper to group all possible ways of 375 * waiting for a synchronous message response. 376 * 377 * @achan: ACPM channel info. 378 * @xfer: reference to the transfer being waited for. 379 * 380 * Return: 0 on success, -errno otherwise. 381 */ 382 static int acpm_wait_for_message_response(struct acpm_chan *achan, 383 const struct acpm_xfer *xfer) 384 { 385 /* Just polling mode supported for now. */ 386 return acpm_dequeue_by_polling(achan, xfer); 387 } 388 389 /** 390 * acpm_do_xfer() - do one transfer. 391 * @handle: pointer to the acpm handle. 392 * @xfer: transfer to initiate and wait for response. 393 * 394 * Return: 0 on success, -errno otherwise. 395 */ 396 int acpm_do_xfer(const struct acpm_handle *handle, const struct acpm_xfer *xfer) 397 { 398 struct acpm_info *acpm = handle_to_acpm_info(handle); 399 struct exynos_mbox_msg msg; 400 struct acpm_chan *achan; 401 u32 idx, tx_front; 402 int ret; 403 404 if (xfer->acpm_chan_id >= acpm->num_chans) 405 return -EINVAL; 406 407 achan = &acpm->chans[xfer->acpm_chan_id]; 408 409 if (!xfer->txd || xfer->txlen > achan->mlen || xfer->rxlen > achan->mlen) 410 return -EINVAL; 411 412 if (!achan->poll_completion) { 413 dev_err(achan->acpm->dev, "Interrupt mode not supported\n"); 414 return -EOPNOTSUPP; 415 } 416 417 scoped_guard(mutex, &achan->tx_lock) { 418 tx_front = readl(achan->tx.front); 419 idx = (tx_front + 1) % achan->qlen; 420 421 ret = acpm_wait_for_queue_slots(achan, idx); 422 if (ret) 423 return ret; 424 425 acpm_prepare_xfer(achan, xfer); 426 427 /* Write TX command. */ 428 __iowrite32_copy(achan->tx.base + achan->mlen * tx_front, 429 xfer->txd, xfer->txlen / 4); 430 431 /* Advance TX front. */ 432 writel(idx, achan->tx.front); 433 } 434 435 msg.chan_id = xfer->acpm_chan_id; 436 msg.chan_type = EXYNOS_MBOX_CHAN_TYPE_DOORBELL; 437 ret = mbox_send_message(achan->chan, (void *)&msg); 438 if (ret < 0) 439 return ret; 440 441 ret = acpm_wait_for_message_response(achan, xfer); 442 443 /* 444 * NOTE: we might prefer not to need the mailbox ticker to manage the 445 * transfer queueing since the protocol layer queues things by itself. 446 * Unfortunately, we have to kick the mailbox framework after we have 447 * received our message. 448 */ 449 mbox_client_txdone(achan->chan, ret); 450 451 return ret; 452 } 453 454 /** 455 * acpm_chan_shmem_get_params() - get channel parameters and addresses of the 456 * TX/RX queues. 457 * @achan: ACPM channel info. 458 * @chan_shmem: __iomem pointer to a channel described in shared memory. 459 */ 460 static void acpm_chan_shmem_get_params(struct acpm_chan *achan, 461 struct acpm_chan_shmem __iomem *chan_shmem) 462 { 463 void __iomem *base = achan->acpm->sram_base; 464 struct acpm_queue *rx = &achan->rx; 465 struct acpm_queue *tx = &achan->tx; 466 467 achan->mlen = readl(&chan_shmem->mlen); 468 achan->poll_completion = readl(&chan_shmem->poll_completion); 469 achan->id = readl(&chan_shmem->id); 470 achan->qlen = readl(&chan_shmem->qlen); 471 472 tx->base = base + readl(&chan_shmem->rx_base); 473 tx->rear = base + readl(&chan_shmem->rx_rear); 474 tx->front = base + readl(&chan_shmem->rx_front); 475 476 rx->base = base + readl(&chan_shmem->tx_base); 477 rx->rear = base + readl(&chan_shmem->tx_rear); 478 rx->front = base + readl(&chan_shmem->tx_front); 479 480 dev_vdbg(achan->acpm->dev, "ID = %d poll = %d, mlen = %d, qlen = %d\n", 481 achan->id, achan->poll_completion, achan->mlen, achan->qlen); 482 } 483 484 /** 485 * acpm_achan_alloc_cmds() - allocate buffers for retrieving data from the ACPM 486 * firmware. 487 * @achan: ACPM channel info. 488 * 489 * Return: 0 on success, -errno otherwise. 490 */ 491 static int acpm_achan_alloc_cmds(struct acpm_chan *achan) 492 { 493 struct device *dev = achan->acpm->dev; 494 struct acpm_rx_data *rx_data; 495 size_t cmd_size, n_cmd; 496 int i; 497 498 if (achan->mlen == 0) 499 return 0; 500 501 cmd_size = sizeof(*(achan->rx_data[0].cmd)); 502 n_cmd = DIV_ROUND_UP_ULL(achan->mlen, cmd_size); 503 504 for (i = 0; i < ACPM_SEQNUM_MAX; i++) { 505 rx_data = &achan->rx_data[i]; 506 rx_data->n_cmd = n_cmd; 507 rx_data->cmd = devm_kcalloc(dev, n_cmd, cmd_size, GFP_KERNEL); 508 if (!rx_data->cmd) 509 return -ENOMEM; 510 } 511 512 return 0; 513 } 514 515 /** 516 * acpm_free_mbox_chans() - free mailbox channels. 517 * @acpm: pointer to driver data. 518 */ 519 static void acpm_free_mbox_chans(struct acpm_info *acpm) 520 { 521 int i; 522 523 for (i = 0; i < acpm->num_chans; i++) 524 if (!IS_ERR_OR_NULL(acpm->chans[i].chan)) 525 mbox_free_channel(acpm->chans[i].chan); 526 } 527 528 /** 529 * acpm_channels_init() - initialize channels based on the configuration data in 530 * the shared memory. 531 * @acpm: pointer to driver data. 532 * 533 * Return: 0 on success, -errno otherwise. 534 */ 535 static int acpm_channels_init(struct acpm_info *acpm) 536 { 537 struct acpm_shmem __iomem *shmem = acpm->shmem; 538 struct acpm_chan_shmem __iomem *chans_shmem; 539 struct device *dev = acpm->dev; 540 int i, ret; 541 542 acpm->num_chans = readl(&shmem->num_chans); 543 acpm->chans = devm_kcalloc(dev, acpm->num_chans, sizeof(*acpm->chans), 544 GFP_KERNEL); 545 if (!acpm->chans) 546 return -ENOMEM; 547 548 chans_shmem = acpm->sram_base + readl(&shmem->chans); 549 550 for (i = 0; i < acpm->num_chans; i++) { 551 struct acpm_chan_shmem __iomem *chan_shmem = &chans_shmem[i]; 552 struct acpm_chan *achan = &acpm->chans[i]; 553 struct mbox_client *cl = &achan->cl; 554 555 achan->acpm = acpm; 556 557 acpm_chan_shmem_get_params(achan, chan_shmem); 558 559 ret = acpm_achan_alloc_cmds(achan); 560 if (ret) 561 return ret; 562 563 mutex_init(&achan->rx_lock); 564 mutex_init(&achan->tx_lock); 565 566 cl->dev = dev; 567 568 achan->chan = mbox_request_channel(cl, 0); 569 if (IS_ERR(achan->chan)) { 570 acpm_free_mbox_chans(acpm); 571 return PTR_ERR(achan->chan); 572 } 573 } 574 575 return 0; 576 } 577 578 /** 579 * acpm_setup_ops() - setup the operations structures. 580 * @acpm: pointer to the driver data. 581 */ 582 static void acpm_setup_ops(struct acpm_info *acpm) 583 { 584 struct acpm_pmic_ops *pmic_ops = &acpm->handle.ops.pmic_ops; 585 586 pmic_ops->read_reg = acpm_pmic_read_reg; 587 pmic_ops->bulk_read = acpm_pmic_bulk_read; 588 pmic_ops->write_reg = acpm_pmic_write_reg; 589 pmic_ops->bulk_write = acpm_pmic_bulk_write; 590 pmic_ops->update_reg = acpm_pmic_update_reg; 591 } 592 593 static int acpm_probe(struct platform_device *pdev) 594 { 595 const struct acpm_match_data *match_data; 596 struct device *dev = &pdev->dev; 597 struct device_node *shmem; 598 struct acpm_info *acpm; 599 resource_size_t size; 600 struct resource res; 601 int ret; 602 603 acpm = devm_kzalloc(dev, sizeof(*acpm), GFP_KERNEL); 604 if (!acpm) 605 return -ENOMEM; 606 607 shmem = of_parse_phandle(dev->of_node, "shmem", 0); 608 ret = of_address_to_resource(shmem, 0, &res); 609 of_node_put(shmem); 610 if (ret) 611 return dev_err_probe(dev, ret, 612 "Failed to get shared memory.\n"); 613 614 size = resource_size(&res); 615 acpm->sram_base = devm_ioremap(dev, res.start, size); 616 if (!acpm->sram_base) 617 return dev_err_probe(dev, -ENOMEM, 618 "Failed to ioremap shared memory.\n"); 619 620 match_data = of_device_get_match_data(dev); 621 if (!match_data) 622 return dev_err_probe(dev, -EINVAL, 623 "Failed to get match data.\n"); 624 625 acpm->shmem = acpm->sram_base + match_data->initdata_base; 626 acpm->dev = dev; 627 628 ret = acpm_channels_init(acpm); 629 if (ret) 630 return ret; 631 632 acpm_setup_ops(acpm); 633 634 platform_set_drvdata(pdev, acpm); 635 636 return 0; 637 } 638 639 /** 640 * acpm_handle_put() - release the handle acquired by acpm_get_by_phandle. 641 * @handle: Handle acquired by acpm_get_by_phandle. 642 */ 643 static void acpm_handle_put(const struct acpm_handle *handle) 644 { 645 struct acpm_info *acpm = handle_to_acpm_info(handle); 646 struct device *dev = acpm->dev; 647 648 module_put(dev->driver->owner); 649 /* Drop reference taken with of_find_device_by_node(). */ 650 put_device(dev); 651 } 652 653 /** 654 * devm_acpm_release() - devres release method. 655 * @dev: pointer to device. 656 * @res: pointer to resource. 657 */ 658 static void devm_acpm_release(struct device *dev, void *res) 659 { 660 acpm_handle_put(*(struct acpm_handle **)res); 661 } 662 663 /** 664 * acpm_get_by_phandle() - get the ACPM handle using DT phandle. 665 * @dev: device pointer requesting ACPM handle. 666 * @property: property name containing phandle on ACPM node. 667 * 668 * Return: pointer to handle on success, ERR_PTR(-errno) otherwise. 669 */ 670 static const struct acpm_handle *acpm_get_by_phandle(struct device *dev, 671 const char *property) 672 { 673 struct platform_device *pdev; 674 struct device_node *acpm_np; 675 struct device_link *link; 676 struct acpm_info *acpm; 677 678 acpm_np = of_parse_phandle(dev->of_node, property, 0); 679 if (!acpm_np) 680 return ERR_PTR(-ENODEV); 681 682 pdev = of_find_device_by_node(acpm_np); 683 if (!pdev) { 684 dev_err(dev, "Cannot find device node %s\n", acpm_np->name); 685 of_node_put(acpm_np); 686 return ERR_PTR(-EPROBE_DEFER); 687 } 688 689 of_node_put(acpm_np); 690 691 acpm = platform_get_drvdata(pdev); 692 if (!acpm) { 693 dev_err(dev, "Cannot get drvdata from %s\n", 694 dev_name(&pdev->dev)); 695 platform_device_put(pdev); 696 return ERR_PTR(-EPROBE_DEFER); 697 } 698 699 if (!try_module_get(pdev->dev.driver->owner)) { 700 dev_err(dev, "Cannot get module reference.\n"); 701 platform_device_put(pdev); 702 return ERR_PTR(-EPROBE_DEFER); 703 } 704 705 link = device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_SUPPLIER); 706 if (!link) { 707 dev_err(&pdev->dev, 708 "Failed to create device link to consumer %s.\n", 709 dev_name(dev)); 710 platform_device_put(pdev); 711 module_put(pdev->dev.driver->owner); 712 return ERR_PTR(-EINVAL); 713 } 714 715 return &acpm->handle; 716 } 717 718 /** 719 * devm_acpm_get_by_phandle() - managed get handle using phandle. 720 * @dev: device pointer requesting ACPM handle. 721 * @property: property name containing phandle on ACPM node. 722 * 723 * Return: pointer to handle on success, ERR_PTR(-errno) otherwise. 724 */ 725 const struct acpm_handle *devm_acpm_get_by_phandle(struct device *dev, 726 const char *property) 727 { 728 const struct acpm_handle **ptr, *handle; 729 730 ptr = devres_alloc(devm_acpm_release, sizeof(*ptr), GFP_KERNEL); 731 if (!ptr) 732 return ERR_PTR(-ENOMEM); 733 734 handle = acpm_get_by_phandle(dev, property); 735 if (!IS_ERR(handle)) { 736 *ptr = handle; 737 devres_add(dev, ptr); 738 } else { 739 devres_free(ptr); 740 } 741 742 return handle; 743 } 744 745 static const struct acpm_match_data acpm_gs101 = { 746 .initdata_base = ACPM_GS101_INITDATA_BASE, 747 }; 748 749 static const struct of_device_id acpm_match[] = { 750 { 751 .compatible = "google,gs101-acpm-ipc", 752 .data = &acpm_gs101, 753 }, 754 {}, 755 }; 756 MODULE_DEVICE_TABLE(of, acpm_match); 757 758 static struct platform_driver acpm_driver = { 759 .probe = acpm_probe, 760 .driver = { 761 .name = "exynos-acpm-protocol", 762 .of_match_table = acpm_match, 763 }, 764 }; 765 module_platform_driver(acpm_driver); 766 767 MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@linaro.org>"); 768 MODULE_DESCRIPTION("Samsung Exynos ACPM mailbox protocol driver"); 769 MODULE_LICENSE("GPL"); 770