1// SPDX-License-Identifier: BSD-3-Clause 2/* 3 * Copyright (c) 2020, MIPI Alliance, Inc. 4 * 5 * Author: Nicolas Pitre <npitre@baylibre.com> 6 * 7 * Note: The I3C HCI v2.0 spec is still in flux. The IBI support is based on 8 * v1.x of the spec and v2.0 will likely be split out. 9 */ 10 11#include <linux/bitfield.h> 12#include <linux/device.h> 13#include <linux/dma-mapping.h> 14#include <linux/errno.h> 15#include <linux/i3c/master.h> 16#include <linux/io.h> 17 18#include "hci.h" 19#include "cmd.h" 20#include "ibi.h" 21 22 23/* 24 * Software Parameter Values (somewhat arb itrary for now). 25 * Some of them could be determined at run time eventually. 26 */ 27 28#define XFER_RINGS 1 /* max: 8 */ 29#define XFER_RING_ENTRIES 16 /* max: 255 */ 30 31#define IBI_RINGS 1 /* max: 8 */ 32#define IBI_STATUS_RING_ENTRIES 32 /* max: 255 */ 33#define IBI_CHUNK_CACHELINES 1 /* max: 256 bytes equivalent */ 34#define IBI_CHUNK_POOL_SIZE 128 /* max: 1023 */ 35 36/* 37 * Ring Header Preamble 38 */ 39 40#define rhs_reg_read(r) readl(hci->RHS_regs + (RHS_##r)) 41#define rhs_reg_write(r, v) writel(v, hci->RHS_regs + (RHS_##r)) 42 43#define RHS_CONTROL 0x00 44#define PREAMBLE_SIZE GENMASK(31, 24) /* Preamble Section Size */ 45#define HEADER_SIZE GENMASK(23, 16) /* Ring Header Size */ 46#define MAX_HEADER_COUNT_CAP GENMASK(7, 4) /* HC Max Header Count */ 47#define MAX_HEADER_COUNT GENMASK(3, 0) /* Driver Max Header Count */ 48 49#define RHS_RHn_OFFSET(n) (0x04 + (n)*4) 50 51/* 52 * Ring Header (Per-Ring Bundle) 53 */ 54 55#define rh_reg_read(r) readl(rh->regs + (RH_##r)) 56#define rh_reg_write(r, v) writel(v, rh->regs + (RH_##r)) 57 58#define RH_CR_SETUP 0x00 /* Command/Response Ring */ 59#define CR_XFER_STRUCT_SIZE GENMASK(31, 24) 60#define CR_RESP_STRUCT_SIZE GENMASK(23, 16) 61#define CR_RING_SIZE GENMASK(8, 0) 62 63#define RH_IBI_SETUP 0x04 64#define IBI_STATUS_STRUCT_SIZE GENMASK(31, 24) 65#define IBI_STATUS_RING_SIZE GENMASK(23, 16) 66#define IBI_DATA_CHUNK_SIZE GENMASK(12, 10) 67#define IBI_DATA_CHUNK_COUNT GENMASK(9, 0) 68 69#define RH_CHUNK_CONTROL 0x08 70 71#define RH_INTR_STATUS 0x10 72#define RH_INTR_STATUS_ENABLE 0x14 73#define RH_INTR_SIGNAL_ENABLE 0x18 74#define RH_INTR_FORCE 0x1c 75#define INTR_IBI_READY BIT(12) 76#define INTR_TRANSFER_COMPLETION BIT(11) 77#define INTR_RING_OP BIT(10) 78#define INTR_TRANSFER_ERR BIT(9) 79#define INTR_WARN_INS_STOP_MODE BIT(7) 80#define INTR_IBI_RING_FULL BIT(6) 81#define INTR_TRANSFER_ABORT BIT(5) 82 83#define RH_RING_STATUS 0x20 84#define RING_STATUS_LOCKED BIT(3) 85#define RING_STATUS_ABORTED BIT(2) 86#define RING_STATUS_RUNNING BIT(1) 87#define RING_STATUS_ENABLED BIT(0) 88 89#define RH_RING_CONTROL 0x24 90#define RING_CTRL_ABORT BIT(2) 91#define RING_CTRL_RUN_STOP BIT(1) 92#define RING_CTRL_ENABLE BIT(0) 93 94#define RH_RING_OPERATION1 0x28 95#define RING_OP1_IBI_DEQ_PTR GENMASK(23, 16) 96#define RING_OP1_CR_SW_DEQ_PTR GENMASK(15, 8) 97#define RING_OP1_CR_ENQ_PTR GENMASK(7, 0) 98 99#define RH_RING_OPERATION2 0x2c 100#define RING_OP2_IBI_ENQ_PTR GENMASK(23, 16) 101#define RING_OP2_CR_DEQ_PTR GENMASK(7, 0) 102 103#define RH_CMD_RING_BASE_LO 0x30 104#define RH_CMD_RING_BASE_HI 0x34 105#define RH_RESP_RING_BASE_LO 0x38 106#define RH_RESP_RING_BASE_HI 0x3c 107#define RH_IBI_STATUS_RING_BASE_LO 0x40 108#define RH_IBI_STATUS_RING_BASE_HI 0x44 109#define RH_IBI_DATA_RING_BASE_LO 0x48 110#define RH_IBI_DATA_RING_BASE_HI 0x4c 111 112#define RH_CMD_RING_SG 0x50 /* Ring Scatter Gather Support */ 113#define RH_RESP_RING_SG 0x54 114#define RH_IBI_STATUS_RING_SG 0x58 115#define RH_IBI_DATA_RING_SG 0x5c 116#define RING_SG_BLP BIT(31) /* Buffer Vs. List Pointer */ 117#define RING_SG_LIST_SIZE GENMASK(15, 0) 118 119/* 120 * Data Buffer Descriptor (in memory) 121 */ 122 123#define DATA_BUF_BLP BIT(31) /* Buffer Vs. List Pointer */ 124#define DATA_BUF_IOC BIT(30) /* Interrupt on Completion */ 125#define DATA_BUF_BLOCK_SIZE GENMASK(15, 0) 126 127 128struct hci_rh_data { 129 void __iomem *regs; 130 void *xfer, *resp, *ibi_status, *ibi_data; 131 dma_addr_t xfer_dma, resp_dma, ibi_status_dma, ibi_data_dma; 132 unsigned int xfer_entries, ibi_status_entries, ibi_chunks_total; 133 unsigned int xfer_struct_sz, resp_struct_sz, ibi_status_sz, ibi_chunk_sz; 134 unsigned int done_ptr, ibi_chunk_ptr; 135 struct hci_xfer **src_xfers; 136 spinlock_t lock; 137 struct completion op_done; 138}; 139 140struct hci_rings_data { 141 unsigned int total; 142 struct hci_rh_data headers[] __counted_by(total); 143}; 144 145struct hci_dma_dev_ibi_data { 146 struct i3c_generic_ibi_pool *pool; 147 unsigned int max_len; 148}; 149 150static inline u32 lo32(dma_addr_t physaddr) 151{ 152 return physaddr; 153} 154 155static inline u32 hi32(dma_addr_t physaddr) 156{ 157 /* trickery to avoid compiler warnings on 32-bit build targets */ 158 if (sizeof(dma_addr_t) > 4) { 159 u64 hi = physaddr; 160 return hi >> 32; 161 } 162 return 0; 163} 164 165static void hci_dma_cleanup(struct i3c_hci *hci) 166{ 167 struct hci_rings_data *rings = hci->io_data; 168 struct hci_rh_data *rh; 169 unsigned int i; 170 171 if (!rings) 172 return; 173 174 for (i = 0; i < rings->total; i++) { 175 rh = &rings->headers[i]; 176 177 rh_reg_write(RING_CONTROL, 0); 178 rh_reg_write(CR_SETUP, 0); 179 rh_reg_write(IBI_SETUP, 0); 180 rh_reg_write(INTR_SIGNAL_ENABLE, 0); 181 182 if (rh->xfer) 183 dma_free_coherent(&hci->master.dev, 184 rh->xfer_struct_sz * rh->xfer_entries, 185 rh->xfer, rh->xfer_dma); 186 if (rh->resp) 187 dma_free_coherent(&hci->master.dev, 188 rh->resp_struct_sz * rh->xfer_entries, 189 rh->resp, rh->resp_dma); 190 kfree(rh->src_xfers); 191 if (rh->ibi_status) 192 dma_free_coherent(&hci->master.dev, 193 rh->ibi_status_sz * rh->ibi_status_entries, 194 rh->ibi_status, rh->ibi_status_dma); 195 if (rh->ibi_data_dma) 196 dma_unmap_single(&hci->master.dev, rh->ibi_data_dma, 197 rh->ibi_chunk_sz * rh->ibi_chunks_total, 198 DMA_FROM_DEVICE); 199 kfree(rh->ibi_data); 200 } 201 202 rhs_reg_write(CONTROL, 0); 203 204 kfree(rings); 205 hci->io_data = NULL; 206} 207 208static int hci_dma_init(struct i3c_hci *hci) 209{ 210 struct hci_rings_data *rings; 211 struct hci_rh_data *rh; 212 u32 regval; 213 unsigned int i, nr_rings, xfers_sz, resps_sz; 214 unsigned int ibi_status_ring_sz, ibi_data_ring_sz; 215 int ret; 216 217 regval = rhs_reg_read(CONTROL); 218 nr_rings = FIELD_GET(MAX_HEADER_COUNT_CAP, regval); 219 dev_info(&hci->master.dev, "%d DMA rings available\n", nr_rings); 220 if (unlikely(nr_rings > 8)) { 221 dev_err(&hci->master.dev, "number of rings should be <= 8\n"); 222 nr_rings = 8; 223 } 224 if (nr_rings > XFER_RINGS) 225 nr_rings = XFER_RINGS; 226 rings = kzalloc(struct_size(rings, headers, nr_rings), GFP_KERNEL); 227 if (!rings) 228 return -ENOMEM; 229 hci->io_data = rings; 230 rings->total = nr_rings; 231 232 regval = FIELD_PREP(MAX_HEADER_COUNT, rings->total); 233 rhs_reg_write(CONTROL, regval); 234 235 for (i = 0; i < rings->total; i++) { 236 u32 offset = rhs_reg_read(RHn_OFFSET(i)); 237 238 dev_info(&hci->master.dev, "Ring %d at offset %#x\n", i, offset); 239 ret = -EINVAL; 240 if (!offset) 241 goto err_out; 242 rh = &rings->headers[i]; 243 rh->regs = hci->base_regs + offset; 244 spin_lock_init(&rh->lock); 245 init_completion(&rh->op_done); 246 247 rh->xfer_entries = XFER_RING_ENTRIES; 248 249 regval = rh_reg_read(CR_SETUP); 250 rh->xfer_struct_sz = FIELD_GET(CR_XFER_STRUCT_SIZE, regval); 251 rh->resp_struct_sz = FIELD_GET(CR_RESP_STRUCT_SIZE, regval); 252 DBG("xfer_struct_sz = %d, resp_struct_sz = %d", 253 rh->xfer_struct_sz, rh->resp_struct_sz); 254 xfers_sz = rh->xfer_struct_sz * rh->xfer_entries; 255 resps_sz = rh->resp_struct_sz * rh->xfer_entries; 256 257 rh->xfer = dma_alloc_coherent(&hci->master.dev, xfers_sz, 258 &rh->xfer_dma, GFP_KERNEL); 259 rh->resp = dma_alloc_coherent(&hci->master.dev, resps_sz, 260 &rh->resp_dma, GFP_KERNEL); 261 rh->src_xfers = 262 kmalloc_array(rh->xfer_entries, sizeof(*rh->src_xfers), 263 GFP_KERNEL); 264 ret = -ENOMEM; 265 if (!rh->xfer || !rh->resp || !rh->src_xfers) 266 goto err_out; 267 268 rh_reg_write(CMD_RING_BASE_LO, lo32(rh->xfer_dma)); 269 rh_reg_write(CMD_RING_BASE_HI, hi32(rh->xfer_dma)); 270 rh_reg_write(RESP_RING_BASE_LO, lo32(rh->resp_dma)); 271 rh_reg_write(RESP_RING_BASE_HI, hi32(rh->resp_dma)); 272 273 regval = FIELD_PREP(CR_RING_SIZE, rh->xfer_entries); 274 rh_reg_write(CR_SETUP, regval); 275 276 rh_reg_write(INTR_STATUS_ENABLE, 0xffffffff); 277 rh_reg_write(INTR_SIGNAL_ENABLE, INTR_IBI_READY | 278 INTR_TRANSFER_COMPLETION | 279 INTR_RING_OP | 280 INTR_TRANSFER_ERR | 281 INTR_WARN_INS_STOP_MODE | 282 INTR_IBI_RING_FULL | 283 INTR_TRANSFER_ABORT); 284 285 /* IBIs */ 286 287 if (i >= IBI_RINGS) 288 goto ring_ready; 289 290 regval = rh_reg_read(IBI_SETUP); 291 rh->ibi_status_sz = FIELD_GET(IBI_STATUS_STRUCT_SIZE, regval); 292 rh->ibi_status_entries = IBI_STATUS_RING_ENTRIES; 293 rh->ibi_chunks_total = IBI_CHUNK_POOL_SIZE; 294 295 rh->ibi_chunk_sz = dma_get_cache_alignment(); 296 rh->ibi_chunk_sz *= IBI_CHUNK_CACHELINES; 297 BUG_ON(rh->ibi_chunk_sz > 256); 298 299 ibi_status_ring_sz = rh->ibi_status_sz * rh->ibi_status_entries; 300 ibi_data_ring_sz = rh->ibi_chunk_sz * rh->ibi_chunks_total; 301 302 rh->ibi_status = 303 dma_alloc_coherent(&hci->master.dev, ibi_status_ring_sz, 304 &rh->ibi_status_dma, GFP_KERNEL); 305 rh->ibi_data = kmalloc(ibi_data_ring_sz, GFP_KERNEL); 306 ret = -ENOMEM; 307 if (!rh->ibi_status || !rh->ibi_data) 308 goto err_out; 309 rh->ibi_data_dma = 310 dma_map_single(&hci->master.dev, rh->ibi_data, 311 ibi_data_ring_sz, DMA_FROM_DEVICE); 312 if (dma_mapping_error(&hci->master.dev, rh->ibi_data_dma)) { 313 rh->ibi_data_dma = 0; 314 ret = -ENOMEM; 315 goto err_out; 316 } 317 318 regval = FIELD_PREP(IBI_STATUS_RING_SIZE, 319 rh->ibi_status_entries) | 320 FIELD_PREP(IBI_DATA_CHUNK_SIZE, 321 ilog2(rh->ibi_chunk_sz) - 2) | 322 FIELD_PREP(IBI_DATA_CHUNK_COUNT, 323 rh->ibi_chunks_total); 324 rh_reg_write(IBI_SETUP, regval); 325 326 regval = rh_reg_read(INTR_SIGNAL_ENABLE); 327 regval |= INTR_IBI_READY; 328 rh_reg_write(INTR_SIGNAL_ENABLE, regval); 329 330ring_ready: 331 rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE | 332 RING_CTRL_RUN_STOP); 333 } 334 335 return 0; 336 337err_out: 338 hci_dma_cleanup(hci); 339 return ret; 340} 341 342static void hci_dma_unmap_xfer(struct i3c_hci *hci, 343 struct hci_xfer *xfer_list, unsigned int n) 344{ 345 struct hci_xfer *xfer; 346 unsigned int i; 347 348 for (i = 0; i < n; i++) { 349 xfer = xfer_list + i; 350 if (!xfer->data) 351 continue; 352 dma_unmap_single(&hci->master.dev, 353 xfer->data_dma, xfer->data_len, 354 xfer->rnw ? DMA_FROM_DEVICE : DMA_TO_DEVICE); 355 } 356} 357 358static int hci_dma_queue_xfer(struct i3c_hci *hci, 359 struct hci_xfer *xfer_list, int n) 360{ 361 struct hci_rings_data *rings = hci->io_data; 362 struct hci_rh_data *rh; 363 unsigned int i, ring, enqueue_ptr; 364 u32 op1_val, op2_val; 365 void *buf; 366 367 /* For now we only use ring 0 */ 368 ring = 0; 369 rh = &rings->headers[ring]; 370 371 op1_val = rh_reg_read(RING_OPERATION1); 372 enqueue_ptr = FIELD_GET(RING_OP1_CR_ENQ_PTR, op1_val); 373 for (i = 0; i < n; i++) { 374 struct hci_xfer *xfer = xfer_list + i; 375 u32 *ring_data = rh->xfer + rh->xfer_struct_sz * enqueue_ptr; 376 377 /* store cmd descriptor */ 378 *ring_data++ = xfer->cmd_desc[0]; 379 *ring_data++ = xfer->cmd_desc[1]; 380 if (hci->cmd == &mipi_i3c_hci_cmd_v2) { 381 *ring_data++ = xfer->cmd_desc[2]; 382 *ring_data++ = xfer->cmd_desc[3]; 383 } 384 385 /* first word of Data Buffer Descriptor Structure */ 386 if (!xfer->data) 387 xfer->data_len = 0; 388 *ring_data++ = 389 FIELD_PREP(DATA_BUF_BLOCK_SIZE, xfer->data_len) | 390 ((i == n - 1) ? DATA_BUF_IOC : 0); 391 392 /* 2nd and 3rd words of Data Buffer Descriptor Structure */ 393 if (xfer->data) { 394 buf = xfer->bounce_buf ? xfer->bounce_buf : xfer->data; 395 xfer->data_dma = 396 dma_map_single(&hci->master.dev, 397 buf, 398 xfer->data_len, 399 xfer->rnw ? 400 DMA_FROM_DEVICE : 401 DMA_TO_DEVICE); 402 if (dma_mapping_error(&hci->master.dev, 403 xfer->data_dma)) { 404 hci_dma_unmap_xfer(hci, xfer_list, i); 405 return -ENOMEM; 406 } 407 *ring_data++ = lo32(xfer->data_dma); 408 *ring_data++ = hi32(xfer->data_dma); 409 } else { 410 *ring_data++ = 0; 411 *ring_data++ = 0; 412 } 413 414 /* remember corresponding xfer struct */ 415 rh->src_xfers[enqueue_ptr] = xfer; 416 /* remember corresponding ring/entry for this xfer structure */ 417 xfer->ring_number = ring; 418 xfer->ring_entry = enqueue_ptr; 419 420 enqueue_ptr = (enqueue_ptr + 1) % rh->xfer_entries; 421 422 /* 423 * We may update the hardware view of the enqueue pointer 424 * only if we didn't reach its dequeue pointer. 425 */ 426 op2_val = rh_reg_read(RING_OPERATION2); 427 if (enqueue_ptr == FIELD_GET(RING_OP2_CR_DEQ_PTR, op2_val)) { 428 /* the ring is full */ 429 hci_dma_unmap_xfer(hci, xfer_list, i + 1); 430 return -EBUSY; 431 } 432 } 433 434 /* take care to update the hardware enqueue pointer atomically */ 435 spin_lock_irq(&rh->lock); 436 op1_val = rh_reg_read(RING_OPERATION1); 437 op1_val &= ~RING_OP1_CR_ENQ_PTR; 438 op1_val |= FIELD_PREP(RING_OP1_CR_ENQ_PTR, enqueue_ptr); 439 rh_reg_write(RING_OPERATION1, op1_val); 440 spin_unlock_irq(&rh->lock); 441 442 return 0; 443} 444 445static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, 446 struct hci_xfer *xfer_list, int n) 447{ 448 struct hci_rings_data *rings = hci->io_data; 449 struct hci_rh_data *rh = &rings->headers[xfer_list[0].ring_number]; 450 unsigned int i; 451 bool did_unqueue = false; 452 453 /* stop the ring */ 454 rh_reg_write(RING_CONTROL, RING_CTRL_ABORT); 455 if (wait_for_completion_timeout(&rh->op_done, HZ) == 0) { 456 /* 457 * We're deep in it if ever this condition is ever met. 458 * Hardware might still be writing to memory, etc. 459 */ 460 dev_crit(&hci->master.dev, "unable to abort the ring\n"); 461 WARN_ON(1); 462 } 463 464 for (i = 0; i < n; i++) { 465 struct hci_xfer *xfer = xfer_list + i; 466 int idx = xfer->ring_entry; 467 468 /* 469 * At the time the abort happened, the xfer might have 470 * completed already. If not then replace corresponding 471 * descriptor entries with a no-op. 472 */ 473 if (idx >= 0) { 474 u32 *ring_data = rh->xfer + rh->xfer_struct_sz * idx; 475 476 /* store no-op cmd descriptor */ 477 *ring_data++ = FIELD_PREP(CMD_0_ATTR, 0x7); 478 *ring_data++ = 0; 479 if (hci->cmd == &mipi_i3c_hci_cmd_v2) { 480 *ring_data++ = 0; 481 *ring_data++ = 0; 482 } 483 484 /* disassociate this xfer struct */ 485 rh->src_xfers[idx] = NULL; 486 487 /* and unmap it */ 488 hci_dma_unmap_xfer(hci, xfer, 1); 489 490 did_unqueue = true; 491 } 492 } 493 494 /* restart the ring */ 495 rh_reg_write(RING_CONTROL, RING_CTRL_ENABLE); 496 497 return did_unqueue; 498} 499 500static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) 501{ 502 u32 op1_val, op2_val, resp, *ring_resp; 503 unsigned int tid, done_ptr = rh->done_ptr; 504 struct hci_xfer *xfer; 505 506 for (;;) { 507 op2_val = rh_reg_read(RING_OPERATION2); 508 if (done_ptr == FIELD_GET(RING_OP2_CR_DEQ_PTR, op2_val)) 509 break; 510 511 ring_resp = rh->resp + rh->resp_struct_sz * done_ptr; 512 resp = *ring_resp; 513 tid = RESP_TID(resp); 514 DBG("resp = 0x%08x", resp); 515 516 xfer = rh->src_xfers[done_ptr]; 517 if (!xfer) { 518 DBG("orphaned ring entry"); 519 } else { 520 hci_dma_unmap_xfer(hci, xfer, 1); 521 xfer->ring_entry = -1; 522 xfer->response = resp; 523 if (tid != xfer->cmd_tid) { 524 dev_err(&hci->master.dev, 525 "response tid=%d when expecting %d\n", 526 tid, xfer->cmd_tid); 527 /* TODO: do something about it? */ 528 } 529 if (xfer->completion) 530 complete(xfer->completion); 531 } 532 533 done_ptr = (done_ptr + 1) % rh->xfer_entries; 534 rh->done_ptr = done_ptr; 535 } 536 537 /* take care to update the software dequeue pointer atomically */ 538 spin_lock(&rh->lock); 539 op1_val = rh_reg_read(RING_OPERATION1); 540 op1_val &= ~RING_OP1_CR_SW_DEQ_PTR; 541 op1_val |= FIELD_PREP(RING_OP1_CR_SW_DEQ_PTR, done_ptr); 542 rh_reg_write(RING_OPERATION1, op1_val); 543 spin_unlock(&rh->lock); 544} 545 546static int hci_dma_request_ibi(struct i3c_hci *hci, struct i3c_dev_desc *dev, 547 const struct i3c_ibi_setup *req) 548{ 549 struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev); 550 struct i3c_generic_ibi_pool *pool; 551 struct hci_dma_dev_ibi_data *dev_ibi; 552 553 dev_ibi = kmalloc(sizeof(*dev_ibi), GFP_KERNEL); 554 if (!dev_ibi) 555 return -ENOMEM; 556 pool = i3c_generic_ibi_alloc_pool(dev, req); 557 if (IS_ERR(pool)) { 558 kfree(dev_ibi); 559 return PTR_ERR(pool); 560 } 561 dev_ibi->pool = pool; 562 dev_ibi->max_len = req->max_payload_len; 563 dev_data->ibi_data = dev_ibi; 564 return 0; 565} 566 567static void hci_dma_free_ibi(struct i3c_hci *hci, struct i3c_dev_desc *dev) 568{ 569 struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev); 570 struct hci_dma_dev_ibi_data *dev_ibi = dev_data->ibi_data; 571 572 dev_data->ibi_data = NULL; 573 i3c_generic_ibi_free_pool(dev_ibi->pool); 574 kfree(dev_ibi); 575} 576 577static void hci_dma_recycle_ibi_slot(struct i3c_hci *hci, 578 struct i3c_dev_desc *dev, 579 struct i3c_ibi_slot *slot) 580{ 581 struct i3c_hci_dev_data *dev_data = i3c_dev_get_master_data(dev); 582 struct hci_dma_dev_ibi_data *dev_ibi = dev_data->ibi_data; 583 584 i3c_generic_ibi_recycle_slot(dev_ibi->pool, slot); 585} 586 587static void hci_dma_process_ibi(struct i3c_hci *hci, struct hci_rh_data *rh) 588{ 589 struct i3c_dev_desc *dev; 590 struct i3c_hci_dev_data *dev_data; 591 struct hci_dma_dev_ibi_data *dev_ibi; 592 struct i3c_ibi_slot *slot; 593 u32 op1_val, op2_val, ibi_status_error; 594 unsigned int ptr, enq_ptr, deq_ptr; 595 unsigned int ibi_size, ibi_chunks, ibi_data_offset, first_part; 596 int ibi_addr, last_ptr; 597 void *ring_ibi_data; 598 dma_addr_t ring_ibi_data_dma; 599 600 op1_val = rh_reg_read(RING_OPERATION1); 601 deq_ptr = FIELD_GET(RING_OP1_IBI_DEQ_PTR, op1_val); 602 603 op2_val = rh_reg_read(RING_OPERATION2); 604 enq_ptr = FIELD_GET(RING_OP2_IBI_ENQ_PTR, op2_val); 605 606 ibi_status_error = 0; 607 ibi_addr = -1; 608 ibi_chunks = 0; 609 ibi_size = 0; 610 last_ptr = -1; 611 612 /* let's find all we can about this IBI */ 613 for (ptr = deq_ptr; ptr != enq_ptr; 614 ptr = (ptr + 1) % rh->ibi_status_entries) { 615 u32 ibi_status, *ring_ibi_status; 616 unsigned int chunks; 617 618 ring_ibi_status = rh->ibi_status + rh->ibi_status_sz * ptr; 619 ibi_status = *ring_ibi_status; 620 DBG("status = %#x", ibi_status); 621 622 if (ibi_status_error) { 623 /* we no longer care */ 624 } else if (ibi_status & IBI_ERROR) { 625 ibi_status_error = ibi_status; 626 } else if (ibi_addr == -1) { 627 ibi_addr = FIELD_GET(IBI_TARGET_ADDR, ibi_status); 628 } else if (ibi_addr != FIELD_GET(IBI_TARGET_ADDR, ibi_status)) { 629 /* the address changed unexpectedly */ 630 ibi_status_error = ibi_status; 631 } 632 633 chunks = FIELD_GET(IBI_CHUNKS, ibi_status); 634 ibi_chunks += chunks; 635 if (!(ibi_status & IBI_LAST_STATUS)) { 636 ibi_size += chunks * rh->ibi_chunk_sz; 637 } else { 638 ibi_size += FIELD_GET(IBI_DATA_LENGTH, ibi_status); 639 last_ptr = ptr; 640 break; 641 } 642 } 643 644 /* validate what we've got */ 645 646 if (last_ptr == -1) { 647 /* this IBI sequence is not yet complete */ 648 DBG("no LAST_STATUS available (e=%d d=%d)", enq_ptr, deq_ptr); 649 return; 650 } 651 deq_ptr = last_ptr + 1; 652 deq_ptr %= rh->ibi_status_entries; 653 654 if (ibi_status_error) { 655 dev_err(&hci->master.dev, "IBI error from %#x\n", ibi_addr); 656 goto done; 657 } 658 659 /* determine who this is for */ 660 dev = i3c_hci_addr_to_dev(hci, ibi_addr); 661 if (!dev) { 662 dev_err(&hci->master.dev, 663 "IBI for unknown device %#x\n", ibi_addr); 664 goto done; 665 } 666 667 dev_data = i3c_dev_get_master_data(dev); 668 dev_ibi = dev_data->ibi_data; 669 if (ibi_size > dev_ibi->max_len) { 670 dev_err(&hci->master.dev, "IBI payload too big (%d > %d)\n", 671 ibi_size, dev_ibi->max_len); 672 goto done; 673 } 674 675 /* 676 * This ring model is not suitable for zero-copy processing of IBIs. 677 * We have the data chunk ring wrap-around to deal with, meaning 678 * that the payload might span multiple chunks beginning at the 679 * end of the ring and wrap to the start of the ring. Furthermore 680 * there is no guarantee that those chunks will be released in order 681 * and in a timely manner by the upper driver. So let's just copy 682 * them to a discrete buffer. In practice they're supposed to be 683 * small anyway. 684 */ 685 slot = i3c_generic_ibi_get_free_slot(dev_ibi->pool); 686 if (!slot) { 687 dev_err(&hci->master.dev, "no free slot for IBI\n"); 688 goto done; 689 } 690 691 /* copy first part of the payload */ 692 ibi_data_offset = rh->ibi_chunk_sz * rh->ibi_chunk_ptr; 693 ring_ibi_data = rh->ibi_data + ibi_data_offset; 694 ring_ibi_data_dma = rh->ibi_data_dma + ibi_data_offset; 695 first_part = (rh->ibi_chunks_total - rh->ibi_chunk_ptr) 696 * rh->ibi_chunk_sz; 697 if (first_part > ibi_size) 698 first_part = ibi_size; 699 dma_sync_single_for_cpu(&hci->master.dev, ring_ibi_data_dma, 700 first_part, DMA_FROM_DEVICE); 701 memcpy(slot->data, ring_ibi_data, first_part); 702 703 /* copy second part if any */ 704 if (ibi_size > first_part) { 705 /* we wrap back to the start and copy remaining data */ 706 ring_ibi_data = rh->ibi_data; 707 ring_ibi_data_dma = rh->ibi_data_dma; 708 dma_sync_single_for_cpu(&hci->master.dev, ring_ibi_data_dma, 709 ibi_size - first_part, DMA_FROM_DEVICE); 710 memcpy(slot->data + first_part, ring_ibi_data, 711 ibi_size - first_part); 712 } 713 714 /* submit it */ 715 slot->dev = dev; 716 slot->len = ibi_size; 717 i3c_master_queue_ibi(dev, slot); 718 719done: 720 /* take care to update the ibi dequeue pointer atomically */ 721 spin_lock(&rh->lock); 722 op1_val = rh_reg_read(RING_OPERATION1); 723 op1_val &= ~RING_OP1_IBI_DEQ_PTR; 724 op1_val |= FIELD_PREP(RING_OP1_IBI_DEQ_PTR, deq_ptr); 725 rh_reg_write(RING_OPERATION1, op1_val); 726 spin_unlock(&rh->lock); 727 728 /* update the chunk pointer */ 729 rh->ibi_chunk_ptr += ibi_chunks; 730 rh->ibi_chunk_ptr %= rh->ibi_chunks_total; 731 732 /* and tell the hardware about freed chunks */ 733 rh_reg_write(CHUNK_CONTROL, rh_reg_read(CHUNK_CONTROL) + ibi_chunks); 734} 735 736static bool hci_dma_irq_handler(struct i3c_hci *hci, unsigned int mask) 737{ 738 struct hci_rings_data *rings = hci->io_data; 739 unsigned int i; 740 bool handled = false; 741 742 for (i = 0; mask && i < rings->total; i++) { 743 struct hci_rh_data *rh; 744 u32 status; 745 746 if (!(mask & BIT(i))) 747 continue; 748 mask &= ~BIT(i); 749 750 rh = &rings->headers[i]; 751 status = rh_reg_read(INTR_STATUS); 752 DBG("rh%d status: %#x", i, status); 753 if (!status) 754 continue; 755 rh_reg_write(INTR_STATUS, status); 756 757 if (status & INTR_IBI_READY) 758 hci_dma_process_ibi(hci, rh); 759 if (status & (INTR_TRANSFER_COMPLETION | INTR_TRANSFER_ERR)) 760 hci_dma_xfer_done(hci, rh); 761 if (status & INTR_RING_OP) 762 complete(&rh->op_done); 763 764 if (status & INTR_TRANSFER_ABORT) { 765 dev_notice_ratelimited(&hci->master.dev, 766 "ring %d: Transfer Aborted\n", i); 767 mipi_i3c_hci_resume(hci); 768 } 769 if (status & INTR_WARN_INS_STOP_MODE) 770 dev_warn_ratelimited(&hci->master.dev, 771 "ring %d: Inserted Stop on Mode Change\n", i); 772 if (status & INTR_IBI_RING_FULL) 773 dev_err_ratelimited(&hci->master.dev, 774 "ring %d: IBI Ring Full Condition\n", i); 775 776 handled = true; 777 } 778 779 return handled; 780} 781 782const struct hci_io_ops mipi_i3c_hci_dma = { 783 .init = hci_dma_init, 784 .cleanup = hci_dma_cleanup, 785 .queue_xfer = hci_dma_queue_xfer, 786 .dequeue_xfer = hci_dma_dequeue_xfer, 787 .irq_handler = hci_dma_irq_handler, 788 .request_ibi = hci_dma_request_ibi, 789 .free_ibi = hci_dma_free_ibi, 790 .recycle_ibi_slot = hci_dma_recycle_ibi_slot, 791}; 792