1// SPDX-License-Identifier: GPL-2.0+ 2// 3// Actions Semi Owl SoCs DMA driver 4// 5// Copyright (c) 2014 Actions Semi Inc. 6// Author: David Liu <liuwei@actions-semi.com> 7// 8// Copyright (c) 2018 Linaro Ltd. 9// Author: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> 10 11#include <linux/bitops.h> 12#include <linux/clk.h> 13#include <linux/delay.h> 14#include <linux/dmaengine.h> 15#include <linux/dma-mapping.h> 16#include <linux/dmapool.h> 17#include <linux/err.h> 18#include <linux/init.h> 19#include <linux/interrupt.h> 20#include <linux/io.h> 21#include <linux/mm.h> 22#include <linux/module.h> 23#include <linux/of_device.h> 24#include <linux/of_dma.h> 25#include <linux/slab.h> 26#include "virt-dma.h" 27 28#define OWL_DMA_FRAME_MAX_LENGTH 0xfffff 29 30/* Global DMA Controller Registers */ 31#define OWL_DMA_IRQ_PD0 0x00 32#define OWL_DMA_IRQ_PD1 0x04 33#define OWL_DMA_IRQ_PD2 0x08 34#define OWL_DMA_IRQ_PD3 0x0C 35#define OWL_DMA_IRQ_EN0 0x10 36#define OWL_DMA_IRQ_EN1 0x14 37#define OWL_DMA_IRQ_EN2 0x18 38#define OWL_DMA_IRQ_EN3 0x1C 39#define OWL_DMA_SECURE_ACCESS_CTL 0x20 40#define OWL_DMA_NIC_QOS 0x24 41#define OWL_DMA_DBGSEL 0x28 42#define OWL_DMA_IDLE_STAT 0x2C 43 44/* Channel Registers */ 45#define OWL_DMA_CHAN_BASE(i) (0x100 + (i) * 0x100) 46#define OWL_DMAX_MODE 0x00 47#define OWL_DMAX_SOURCE 0x04 48#define OWL_DMAX_DESTINATION 0x08 49#define OWL_DMAX_FRAME_LEN 0x0C 50#define OWL_DMAX_FRAME_CNT 0x10 51#define OWL_DMAX_REMAIN_FRAME_CNT 0x14 52#define OWL_DMAX_REMAIN_CNT 0x18 53#define OWL_DMAX_SOURCE_STRIDE 0x1C 54#define OWL_DMAX_DESTINATION_STRIDE 0x20 55#define OWL_DMAX_START 0x24 56#define OWL_DMAX_PAUSE 0x28 57#define OWL_DMAX_CHAINED_CTL 0x2C 58#define OWL_DMAX_CONSTANT 0x30 59#define OWL_DMAX_LINKLIST_CTL 0x34 60#define OWL_DMAX_NEXT_DESCRIPTOR 0x38 61#define OWL_DMAX_CURRENT_DESCRIPTOR_NUM 0x3C 62#define OWL_DMAX_INT_CTL 0x40 63#define OWL_DMAX_INT_STATUS 0x44 64#define OWL_DMAX_CURRENT_SOURCE_POINTER 0x48 65#define OWL_DMAX_CURRENT_DESTINATION_POINTER 0x4C 66 67/* OWL_DMAX_MODE Bits */ 68#define OWL_DMA_MODE_TS(x) (((x) & GENMASK(5, 0)) << 0) 69#define OWL_DMA_MODE_ST(x) (((x) & GENMASK(1, 0)) << 8) 70#define OWL_DMA_MODE_ST_DEV OWL_DMA_MODE_ST(0) 71#define OWL_DMA_MODE_ST_DCU OWL_DMA_MODE_ST(2) 72#define OWL_DMA_MODE_ST_SRAM OWL_DMA_MODE_ST(3) 73#define OWL_DMA_MODE_DT(x) (((x) & GENMASK(1, 0)) << 10) 74#define OWL_DMA_MODE_DT_DEV OWL_DMA_MODE_DT(0) 75#define OWL_DMA_MODE_DT_DCU OWL_DMA_MODE_DT(2) 76#define OWL_DMA_MODE_DT_SRAM OWL_DMA_MODE_DT(3) 77#define OWL_DMA_MODE_SAM(x) (((x) & GENMASK(1, 0)) << 16) 78#define OWL_DMA_MODE_SAM_CONST OWL_DMA_MODE_SAM(0) 79#define OWL_DMA_MODE_SAM_INC OWL_DMA_MODE_SAM(1) 80#define OWL_DMA_MODE_SAM_STRIDE OWL_DMA_MODE_SAM(2) 81#define OWL_DMA_MODE_DAM(x) (((x) & GENMASK(1, 0)) << 18) 82#define OWL_DMA_MODE_DAM_CONST OWL_DMA_MODE_DAM(0) 83#define OWL_DMA_MODE_DAM_INC OWL_DMA_MODE_DAM(1) 84#define OWL_DMA_MODE_DAM_STRIDE OWL_DMA_MODE_DAM(2) 85#define OWL_DMA_MODE_PW(x) (((x) & GENMASK(2, 0)) << 20) 86#define OWL_DMA_MODE_CB BIT(23) 87#define OWL_DMA_MODE_NDDBW(x) (((x) & 0x1) << 28) 88#define OWL_DMA_MODE_NDDBW_32BIT OWL_DMA_MODE_NDDBW(0) 89#define OWL_DMA_MODE_NDDBW_8BIT OWL_DMA_MODE_NDDBW(1) 90#define OWL_DMA_MODE_CFE BIT(29) 91#define OWL_DMA_MODE_LME BIT(30) 92#define OWL_DMA_MODE_CME BIT(31) 93 94/* OWL_DMAX_LINKLIST_CTL Bits */ 95#define OWL_DMA_LLC_SAV(x) (((x) & GENMASK(1, 0)) << 8) 96#define OWL_DMA_LLC_SAV_INC OWL_DMA_LLC_SAV(0) 97#define OWL_DMA_LLC_SAV_LOAD_NEXT OWL_DMA_LLC_SAV(1) 98#define OWL_DMA_LLC_SAV_LOAD_PREV OWL_DMA_LLC_SAV(2) 99#define OWL_DMA_LLC_DAV(x) (((x) & GENMASK(1, 0)) << 10) 100#define OWL_DMA_LLC_DAV_INC OWL_DMA_LLC_DAV(0) 101#define OWL_DMA_LLC_DAV_LOAD_NEXT OWL_DMA_LLC_DAV(1) 102#define OWL_DMA_LLC_DAV_LOAD_PREV OWL_DMA_LLC_DAV(2) 103#define OWL_DMA_LLC_SUSPEND BIT(16) 104 105/* OWL_DMAX_INT_CTL Bits */ 106#define OWL_DMA_INTCTL_BLOCK BIT(0) 107#define OWL_DMA_INTCTL_SUPER_BLOCK BIT(1) 108#define OWL_DMA_INTCTL_FRAME BIT(2) 109#define OWL_DMA_INTCTL_HALF_FRAME BIT(3) 110#define OWL_DMA_INTCTL_LAST_FRAME BIT(4) 111 112/* OWL_DMAX_INT_STATUS Bits */ 113#define OWL_DMA_INTSTAT_BLOCK BIT(0) 114#define OWL_DMA_INTSTAT_SUPER_BLOCK BIT(1) 115#define OWL_DMA_INTSTAT_FRAME BIT(2) 116#define OWL_DMA_INTSTAT_HALF_FRAME BIT(3) 117#define OWL_DMA_INTSTAT_LAST_FRAME BIT(4) 118 119/* Pack shift and newshift in a single word */ 120#define BIT_FIELD(val, width, shift, newshift) \ 121 ((((val) >> (shift)) & ((BIT(width)) - 1)) << (newshift)) 122 123/* Frame count value is fixed as 1 */ 124#define FCNT_VAL 0x1 125 126/** 127 * enum owl_dmadesc_offsets - Describe DMA descriptor, hardware link 128 * list for dma transfer 129 * @OWL_DMADESC_NEXT_LLI: physical address of the next link list 130 * @OWL_DMADESC_SADDR: source physical address 131 * @OWL_DMADESC_DADDR: destination physical address 132 * @OWL_DMADESC_FLEN: frame length 133 * @OWL_DMADESC_SRC_STRIDE: source stride 134 * @OWL_DMADESC_DST_STRIDE: destination stride 135 * @OWL_DMADESC_CTRLA: dma_mode and linklist ctrl config 136 * @OWL_DMADESC_CTRLB: interrupt config 137 * @OWL_DMADESC_CONST_NUM: data for constant fill 138 * @OWL_DMADESC_SIZE: max size of this enum 139 */ 140enum owl_dmadesc_offsets { 141 OWL_DMADESC_NEXT_LLI = 0, 142 OWL_DMADESC_SADDR, 143 OWL_DMADESC_DADDR, 144 OWL_DMADESC_FLEN, 145 OWL_DMADESC_SRC_STRIDE, 146 OWL_DMADESC_DST_STRIDE, 147 OWL_DMADESC_CTRLA, 148 OWL_DMADESC_CTRLB, 149 OWL_DMADESC_CONST_NUM, 150 OWL_DMADESC_SIZE 151}; 152 153enum owl_dma_id { 154 S900_DMA, 155 S700_DMA, 156}; 157 158/** 159 * struct owl_dma_lli - Link list for dma transfer 160 * @hw: hardware link list 161 * @phys: physical address of hardware link list 162 * @node: node for txd's lli_list 163 */ 164struct owl_dma_lli { 165 u32 hw[OWL_DMADESC_SIZE]; 166 dma_addr_t phys; 167 struct list_head node; 168}; 169 170/** 171 * struct owl_dma_txd - Wrapper for struct dma_async_tx_descriptor 172 * @vd: virtual DMA descriptor 173 * @lli_list: link list of lli nodes 174 * @cyclic: flag to indicate cyclic transfers 175 */ 176struct owl_dma_txd { 177 struct virt_dma_desc vd; 178 struct list_head lli_list; 179 bool cyclic; 180}; 181 182/** 183 * struct owl_dma_pchan - Holder for the physical channels 184 * @id: physical index to this channel 185 * @base: virtual memory base for the dma channel 186 * @vchan: the virtual channel currently being served by this physical channel 187 */ 188struct owl_dma_pchan { 189 u32 id; 190 void __iomem *base; 191 struct owl_dma_vchan *vchan; 192}; 193 194/** 195 * struct owl_dma_pchan - Wrapper for DMA ENGINE channel 196 * @vc: wrappped virtual channel 197 * @pchan: the physical channel utilized by this channel 198 * @txd: active transaction on this channel 199 * @cfg: slave configuration for this channel 200 * @drq: physical DMA request ID for this channel 201 */ 202struct owl_dma_vchan { 203 struct virt_dma_chan vc; 204 struct owl_dma_pchan *pchan; 205 struct owl_dma_txd *txd; 206 struct dma_slave_config cfg; 207 u8 drq; 208}; 209 210/** 211 * struct owl_dma - Holder for the Owl DMA controller 212 * @dma: dma engine for this instance 213 * @base: virtual memory base for the DMA controller 214 * @clk: clock for the DMA controller 215 * @lock: a lock to use when change DMA controller global register 216 * @lli_pool: a pool for the LLI descriptors 217 * @irq: interrupt ID for the DMA controller 218 * @nr_pchans: the number of physical channels 219 * @pchans: array of data for the physical channels 220 * @nr_vchans: the number of physical channels 221 * @vchans: array of data for the physical channels 222 * @devid: device id based on OWL SoC 223 */ 224struct owl_dma { 225 struct dma_device dma; 226 void __iomem *base; 227 struct clk *clk; 228 spinlock_t lock; 229 struct dma_pool *lli_pool; 230 int irq; 231 232 unsigned int nr_pchans; 233 struct owl_dma_pchan *pchans; 234 235 unsigned int nr_vchans; 236 struct owl_dma_vchan *vchans; 237 enum owl_dma_id devid; 238}; 239 240static void pchan_update(struct owl_dma_pchan *pchan, u32 reg, 241 u32 val, bool state) 242{ 243 u32 regval; 244 245 regval = readl(pchan->base + reg); 246 247 if (state) 248 regval |= val; 249 else 250 regval &= ~val; 251 252 writel(val, pchan->base + reg); 253} 254 255static void pchan_writel(struct owl_dma_pchan *pchan, u32 reg, u32 data) 256{ 257 writel(data, pchan->base + reg); 258} 259 260static u32 pchan_readl(struct owl_dma_pchan *pchan, u32 reg) 261{ 262 return readl(pchan->base + reg); 263} 264 265static void dma_update(struct owl_dma *od, u32 reg, u32 val, bool state) 266{ 267 u32 regval; 268 269 regval = readl(od->base + reg); 270 271 if (state) 272 regval |= val; 273 else 274 regval &= ~val; 275 276 writel(val, od->base + reg); 277} 278 279static void dma_writel(struct owl_dma *od, u32 reg, u32 data) 280{ 281 writel(data, od->base + reg); 282} 283 284static u32 dma_readl(struct owl_dma *od, u32 reg) 285{ 286 return readl(od->base + reg); 287} 288 289static inline struct owl_dma *to_owl_dma(struct dma_device *dd) 290{ 291 return container_of(dd, struct owl_dma, dma); 292} 293 294static struct device *chan2dev(struct dma_chan *chan) 295{ 296 return &chan->dev->device; 297} 298 299static inline struct owl_dma_vchan *to_owl_vchan(struct dma_chan *chan) 300{ 301 return container_of(chan, struct owl_dma_vchan, vc.chan); 302} 303 304static inline struct owl_dma_txd *to_owl_txd(struct dma_async_tx_descriptor *tx) 305{ 306 return container_of(tx, struct owl_dma_txd, vd.tx); 307} 308 309static inline u32 llc_hw_ctrla(u32 mode, u32 llc_ctl) 310{ 311 u32 ctl; 312 313 ctl = BIT_FIELD(mode, 4, 28, 28) | 314 BIT_FIELD(mode, 8, 16, 20) | 315 BIT_FIELD(mode, 4, 8, 16) | 316 BIT_FIELD(mode, 6, 0, 10) | 317 BIT_FIELD(llc_ctl, 2, 10, 8) | 318 BIT_FIELD(llc_ctl, 2, 8, 6); 319 320 return ctl; 321} 322 323static inline u32 llc_hw_ctrlb(u32 int_ctl) 324{ 325 u32 ctl; 326 327 /* 328 * Irrespective of the SoC, ctrlb value starts filling from 329 * bit 18. 330 */ 331 ctl = BIT_FIELD(int_ctl, 7, 0, 18); 332 333 return ctl; 334} 335 336static u32 llc_hw_flen(struct owl_dma_lli *lli) 337{ 338 return lli->hw[OWL_DMADESC_FLEN] & GENMASK(19, 0); 339} 340 341static void owl_dma_free_lli(struct owl_dma *od, 342 struct owl_dma_lli *lli) 343{ 344 list_del(&lli->node); 345 dma_pool_free(od->lli_pool, lli, lli->phys); 346} 347 348static struct owl_dma_lli *owl_dma_alloc_lli(struct owl_dma *od) 349{ 350 struct owl_dma_lli *lli; 351 dma_addr_t phys; 352 353 lli = dma_pool_alloc(od->lli_pool, GFP_NOWAIT, &phys); 354 if (!lli) 355 return NULL; 356 357 INIT_LIST_HEAD(&lli->node); 358 lli->phys = phys; 359 360 return lli; 361} 362 363static struct owl_dma_lli *owl_dma_add_lli(struct owl_dma_txd *txd, 364 struct owl_dma_lli *prev, 365 struct owl_dma_lli *next, 366 bool is_cyclic) 367{ 368 if (!is_cyclic) 369 list_add_tail(&next->node, &txd->lli_list); 370 371 if (prev) { 372 prev->hw[OWL_DMADESC_NEXT_LLI] = next->phys; 373 prev->hw[OWL_DMADESC_CTRLA] |= 374 llc_hw_ctrla(OWL_DMA_MODE_LME, 0); 375 } 376 377 return next; 378} 379 380static inline int owl_dma_cfg_lli(struct owl_dma_vchan *vchan, 381 struct owl_dma_lli *lli, 382 dma_addr_t src, dma_addr_t dst, 383 u32 len, enum dma_transfer_direction dir, 384 struct dma_slave_config *sconfig, 385 bool is_cyclic) 386{ 387 struct owl_dma *od = to_owl_dma(vchan->vc.chan.device); 388 u32 mode, ctrlb; 389 390 mode = OWL_DMA_MODE_PW(0); 391 392 switch (dir) { 393 case DMA_MEM_TO_MEM: 394 mode |= OWL_DMA_MODE_TS(0) | OWL_DMA_MODE_ST_DCU | 395 OWL_DMA_MODE_DT_DCU | OWL_DMA_MODE_SAM_INC | 396 OWL_DMA_MODE_DAM_INC; 397 398 break; 399 case DMA_MEM_TO_DEV: 400 mode |= OWL_DMA_MODE_TS(vchan->drq) 401 | OWL_DMA_MODE_ST_DCU | OWL_DMA_MODE_DT_DEV 402 | OWL_DMA_MODE_SAM_INC | OWL_DMA_MODE_DAM_CONST; 403 404 /* 405 * Hardware only supports 32bit and 8bit buswidth. Since the 406 * default is 32bit, select 8bit only when requested. 407 */ 408 if (sconfig->dst_addr_width == DMA_SLAVE_BUSWIDTH_1_BYTE) 409 mode |= OWL_DMA_MODE_NDDBW_8BIT; 410 411 break; 412 case DMA_DEV_TO_MEM: 413 mode |= OWL_DMA_MODE_TS(vchan->drq) 414 | OWL_DMA_MODE_ST_DEV | OWL_DMA_MODE_DT_DCU 415 | OWL_DMA_MODE_SAM_CONST | OWL_DMA_MODE_DAM_INC; 416 417 /* 418 * Hardware only supports 32bit and 8bit buswidth. Since the 419 * default is 32bit, select 8bit only when requested. 420 */ 421 if (sconfig->src_addr_width == DMA_SLAVE_BUSWIDTH_1_BYTE) 422 mode |= OWL_DMA_MODE_NDDBW_8BIT; 423 424 break; 425 default: 426 return -EINVAL; 427 } 428 429 lli->hw[OWL_DMADESC_CTRLA] = llc_hw_ctrla(mode, 430 OWL_DMA_LLC_SAV_LOAD_NEXT | 431 OWL_DMA_LLC_DAV_LOAD_NEXT); 432 433 if (is_cyclic) 434 ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_BLOCK); 435 else 436 ctrlb = llc_hw_ctrlb(OWL_DMA_INTCTL_SUPER_BLOCK); 437 438 lli->hw[OWL_DMADESC_NEXT_LLI] = 0; /* One link list by default */ 439 lli->hw[OWL_DMADESC_SADDR] = src; 440 lli->hw[OWL_DMADESC_DADDR] = dst; 441 lli->hw[OWL_DMADESC_SRC_STRIDE] = 0; 442 lli->hw[OWL_DMADESC_DST_STRIDE] = 0; 443 444 if (od->devid == S700_DMA) { 445 /* Max frame length is 1MB */ 446 lli->hw[OWL_DMADESC_FLEN] = len; 447 /* 448 * On S700, word starts from offset 0x1C is shared between 449 * frame count and ctrlb, where first 12 bits are for frame 450 * count and rest of 20 bits are for ctrlb. 451 */ 452 lli->hw[OWL_DMADESC_CTRLB] = FCNT_VAL | ctrlb; 453 } else { 454 /* 455 * On S900, word starts from offset 0xC is shared between 456 * frame length (max frame length is 1MB) and frame count, 457 * where first 20 bits are for frame length and rest of 458 * 12 bits are for frame count. 459 */ 460 lli->hw[OWL_DMADESC_FLEN] = len | FCNT_VAL << 20; 461 lli->hw[OWL_DMADESC_CTRLB] = ctrlb; 462 } 463 464 return 0; 465} 466 467static struct owl_dma_pchan *owl_dma_get_pchan(struct owl_dma *od, 468 struct owl_dma_vchan *vchan) 469{ 470 struct owl_dma_pchan *pchan = NULL; 471 unsigned long flags; 472 int i; 473 474 for (i = 0; i < od->nr_pchans; i++) { 475 pchan = &od->pchans[i]; 476 477 spin_lock_irqsave(&od->lock, flags); 478 if (!pchan->vchan) { 479 pchan->vchan = vchan; 480 spin_unlock_irqrestore(&od->lock, flags); 481 break; 482 } 483 484 spin_unlock_irqrestore(&od->lock, flags); 485 } 486 487 return pchan; 488} 489 490static int owl_dma_pchan_busy(struct owl_dma *od, struct owl_dma_pchan *pchan) 491{ 492 unsigned int val; 493 494 val = dma_readl(od, OWL_DMA_IDLE_STAT); 495 496 return !(val & (1 << pchan->id)); 497} 498 499static void owl_dma_terminate_pchan(struct owl_dma *od, 500 struct owl_dma_pchan *pchan) 501{ 502 unsigned long flags; 503 u32 irq_pd; 504 505 pchan_writel(pchan, OWL_DMAX_START, 0); 506 pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); 507 508 spin_lock_irqsave(&od->lock, flags); 509 dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), false); 510 511 irq_pd = dma_readl(od, OWL_DMA_IRQ_PD0); 512 if (irq_pd & (1 << pchan->id)) { 513 dev_warn(od->dma.dev, 514 "terminating pchan %d that still has pending irq\n", 515 pchan->id); 516 dma_writel(od, OWL_DMA_IRQ_PD0, (1 << pchan->id)); 517 } 518 519 pchan->vchan = NULL; 520 521 spin_unlock_irqrestore(&od->lock, flags); 522} 523 524static void owl_dma_pause_pchan(struct owl_dma_pchan *pchan) 525{ 526 pchan_writel(pchan, 1, OWL_DMAX_PAUSE); 527} 528 529static void owl_dma_resume_pchan(struct owl_dma_pchan *pchan) 530{ 531 pchan_writel(pchan, 0, OWL_DMAX_PAUSE); 532} 533 534static int owl_dma_start_next_txd(struct owl_dma_vchan *vchan) 535{ 536 struct owl_dma *od = to_owl_dma(vchan->vc.chan.device); 537 struct virt_dma_desc *vd = vchan_next_desc(&vchan->vc); 538 struct owl_dma_pchan *pchan = vchan->pchan; 539 struct owl_dma_txd *txd = to_owl_txd(&vd->tx); 540 struct owl_dma_lli *lli; 541 unsigned long flags; 542 u32 int_ctl; 543 544 list_del(&vd->node); 545 546 vchan->txd = txd; 547 548 /* Wait for channel inactive */ 549 while (owl_dma_pchan_busy(od, pchan)) 550 cpu_relax(); 551 552 lli = list_first_entry(&txd->lli_list, 553 struct owl_dma_lli, node); 554 555 if (txd->cyclic) 556 int_ctl = OWL_DMA_INTCTL_BLOCK; 557 else 558 int_ctl = OWL_DMA_INTCTL_SUPER_BLOCK; 559 560 pchan_writel(pchan, OWL_DMAX_MODE, OWL_DMA_MODE_LME); 561 pchan_writel(pchan, OWL_DMAX_LINKLIST_CTL, 562 OWL_DMA_LLC_SAV_LOAD_NEXT | OWL_DMA_LLC_DAV_LOAD_NEXT); 563 pchan_writel(pchan, OWL_DMAX_NEXT_DESCRIPTOR, lli->phys); 564 pchan_writel(pchan, OWL_DMAX_INT_CTL, int_ctl); 565 566 /* Clear IRQ status for this pchan */ 567 pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); 568 569 spin_lock_irqsave(&od->lock, flags); 570 571 dma_update(od, OWL_DMA_IRQ_EN0, (1 << pchan->id), true); 572 573 spin_unlock_irqrestore(&od->lock, flags); 574 575 dev_dbg(chan2dev(&vchan->vc.chan), "starting pchan %d\n", pchan->id); 576 577 /* Start DMA transfer for this pchan */ 578 pchan_writel(pchan, OWL_DMAX_START, 0x1); 579 580 return 0; 581} 582 583static void owl_dma_phy_free(struct owl_dma *od, struct owl_dma_vchan *vchan) 584{ 585 /* Ensure that the physical channel is stopped */ 586 owl_dma_terminate_pchan(od, vchan->pchan); 587 588 vchan->pchan = NULL; 589} 590 591static irqreturn_t owl_dma_interrupt(int irq, void *dev_id) 592{ 593 struct owl_dma *od = dev_id; 594 struct owl_dma_vchan *vchan; 595 struct owl_dma_pchan *pchan; 596 unsigned long pending; 597 int i; 598 unsigned int global_irq_pending, chan_irq_pending; 599 600 spin_lock(&od->lock); 601 602 pending = dma_readl(od, OWL_DMA_IRQ_PD0); 603 604 /* Clear IRQ status for each pchan */ 605 for_each_set_bit(i, &pending, od->nr_pchans) { 606 pchan = &od->pchans[i]; 607 pchan_update(pchan, OWL_DMAX_INT_STATUS, 0xff, false); 608 } 609 610 /* Clear pending IRQ */ 611 dma_writel(od, OWL_DMA_IRQ_PD0, pending); 612 613 /* Check missed pending IRQ */ 614 for (i = 0; i < od->nr_pchans; i++) { 615 pchan = &od->pchans[i]; 616 chan_irq_pending = pchan_readl(pchan, OWL_DMAX_INT_CTL) & 617 pchan_readl(pchan, OWL_DMAX_INT_STATUS); 618 619 /* Dummy read to ensure OWL_DMA_IRQ_PD0 value is updated */ 620 dma_readl(od, OWL_DMA_IRQ_PD0); 621 622 global_irq_pending = dma_readl(od, OWL_DMA_IRQ_PD0); 623 624 if (chan_irq_pending && !(global_irq_pending & BIT(i))) { 625 dev_dbg(od->dma.dev, 626 "global and channel IRQ pending match err\n"); 627 628 /* Clear IRQ status for this pchan */ 629 pchan_update(pchan, OWL_DMAX_INT_STATUS, 630 0xff, false); 631 632 /* Update global IRQ pending */ 633 pending |= BIT(i); 634 } 635 } 636 637 spin_unlock(&od->lock); 638 639 for_each_set_bit(i, &pending, od->nr_pchans) { 640 struct owl_dma_txd *txd; 641 642 pchan = &od->pchans[i]; 643 644 vchan = pchan->vchan; 645 if (!vchan) { 646 dev_warn(od->dma.dev, "no vchan attached on pchan %d\n", 647 pchan->id); 648 continue; 649 } 650 651 spin_lock(&vchan->vc.lock); 652 653 txd = vchan->txd; 654 if (txd) { 655 vchan->txd = NULL; 656 657 vchan_cookie_complete(&txd->vd); 658 659 /* 660 * Start the next descriptor (if any), 661 * otherwise free this channel. 662 */ 663 if (vchan_next_desc(&vchan->vc)) 664 owl_dma_start_next_txd(vchan); 665 else 666 owl_dma_phy_free(od, vchan); 667 } 668 669 spin_unlock(&vchan->vc.lock); 670 } 671 672 return IRQ_HANDLED; 673} 674 675static void owl_dma_free_txd(struct owl_dma *od, struct owl_dma_txd *txd) 676{ 677 struct owl_dma_lli *lli, *_lli; 678 679 if (unlikely(!txd)) 680 return; 681 682 list_for_each_entry_safe(lli, _lli, &txd->lli_list, node) 683 owl_dma_free_lli(od, lli); 684 685 kfree(txd); 686} 687 688static void owl_dma_desc_free(struct virt_dma_desc *vd) 689{ 690 struct owl_dma *od = to_owl_dma(vd->tx.chan->device); 691 struct owl_dma_txd *txd = to_owl_txd(&vd->tx); 692 693 owl_dma_free_txd(od, txd); 694} 695 696static int owl_dma_terminate_all(struct dma_chan *chan) 697{ 698 struct owl_dma *od = to_owl_dma(chan->device); 699 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 700 unsigned long flags; 701 LIST_HEAD(head); 702 703 spin_lock_irqsave(&vchan->vc.lock, flags); 704 705 if (vchan->pchan) 706 owl_dma_phy_free(od, vchan); 707 708 if (vchan->txd) { 709 owl_dma_desc_free(&vchan->txd->vd); 710 vchan->txd = NULL; 711 } 712 713 vchan_get_all_descriptors(&vchan->vc, &head); 714 715 spin_unlock_irqrestore(&vchan->vc.lock, flags); 716 717 vchan_dma_desc_free_list(&vchan->vc, &head); 718 719 return 0; 720} 721 722static int owl_dma_config(struct dma_chan *chan, 723 struct dma_slave_config *config) 724{ 725 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 726 727 /* Reject definitely invalid configurations */ 728 if (config->src_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES || 729 config->dst_addr_width == DMA_SLAVE_BUSWIDTH_8_BYTES) 730 return -EINVAL; 731 732 memcpy(&vchan->cfg, config, sizeof(struct dma_slave_config)); 733 734 return 0; 735} 736 737static int owl_dma_pause(struct dma_chan *chan) 738{ 739 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 740 unsigned long flags; 741 742 spin_lock_irqsave(&vchan->vc.lock, flags); 743 744 owl_dma_pause_pchan(vchan->pchan); 745 746 spin_unlock_irqrestore(&vchan->vc.lock, flags); 747 748 return 0; 749} 750 751static int owl_dma_resume(struct dma_chan *chan) 752{ 753 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 754 unsigned long flags; 755 756 if (!vchan->pchan && !vchan->txd) 757 return 0; 758 759 dev_dbg(chan2dev(chan), "vchan %p: resume\n", &vchan->vc); 760 761 spin_lock_irqsave(&vchan->vc.lock, flags); 762 763 owl_dma_resume_pchan(vchan->pchan); 764 765 spin_unlock_irqrestore(&vchan->vc.lock, flags); 766 767 return 0; 768} 769 770static u32 owl_dma_getbytes_chan(struct owl_dma_vchan *vchan) 771{ 772 struct owl_dma_pchan *pchan; 773 struct owl_dma_txd *txd; 774 struct owl_dma_lli *lli; 775 unsigned int next_lli_phy; 776 size_t bytes; 777 778 pchan = vchan->pchan; 779 txd = vchan->txd; 780 781 if (!pchan || !txd) 782 return 0; 783 784 /* Get remain count of current node in link list */ 785 bytes = pchan_readl(pchan, OWL_DMAX_REMAIN_CNT); 786 787 /* Loop through the preceding nodes to get total remaining bytes */ 788 if (pchan_readl(pchan, OWL_DMAX_MODE) & OWL_DMA_MODE_LME) { 789 next_lli_phy = pchan_readl(pchan, OWL_DMAX_NEXT_DESCRIPTOR); 790 list_for_each_entry(lli, &txd->lli_list, node) { 791 /* Start from the next active node */ 792 if (lli->phys == next_lli_phy) { 793 list_for_each_entry(lli, &txd->lli_list, node) 794 bytes += llc_hw_flen(lli); 795 break; 796 } 797 } 798 } 799 800 return bytes; 801} 802 803static enum dma_status owl_dma_tx_status(struct dma_chan *chan, 804 dma_cookie_t cookie, 805 struct dma_tx_state *state) 806{ 807 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 808 struct owl_dma_lli *lli; 809 struct virt_dma_desc *vd; 810 struct owl_dma_txd *txd; 811 enum dma_status ret; 812 unsigned long flags; 813 size_t bytes = 0; 814 815 ret = dma_cookie_status(chan, cookie, state); 816 if (ret == DMA_COMPLETE || !state) 817 return ret; 818 819 spin_lock_irqsave(&vchan->vc.lock, flags); 820 821 vd = vchan_find_desc(&vchan->vc, cookie); 822 if (vd) { 823 txd = to_owl_txd(&vd->tx); 824 list_for_each_entry(lli, &txd->lli_list, node) 825 bytes += llc_hw_flen(lli); 826 } else { 827 bytes = owl_dma_getbytes_chan(vchan); 828 } 829 830 spin_unlock_irqrestore(&vchan->vc.lock, flags); 831 832 dma_set_residue(state, bytes); 833 834 return ret; 835} 836 837static void owl_dma_phy_alloc_and_start(struct owl_dma_vchan *vchan) 838{ 839 struct owl_dma *od = to_owl_dma(vchan->vc.chan.device); 840 struct owl_dma_pchan *pchan; 841 842 pchan = owl_dma_get_pchan(od, vchan); 843 if (!pchan) 844 return; 845 846 dev_dbg(od->dma.dev, "allocated pchan %d\n", pchan->id); 847 848 vchan->pchan = pchan; 849 owl_dma_start_next_txd(vchan); 850} 851 852static void owl_dma_issue_pending(struct dma_chan *chan) 853{ 854 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 855 unsigned long flags; 856 857 spin_lock_irqsave(&vchan->vc.lock, flags); 858 if (vchan_issue_pending(&vchan->vc)) { 859 if (!vchan->pchan) 860 owl_dma_phy_alloc_and_start(vchan); 861 } 862 spin_unlock_irqrestore(&vchan->vc.lock, flags); 863} 864 865static struct dma_async_tx_descriptor 866 *owl_dma_prep_memcpy(struct dma_chan *chan, 867 dma_addr_t dst, dma_addr_t src, 868 size_t len, unsigned long flags) 869{ 870 struct owl_dma *od = to_owl_dma(chan->device); 871 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 872 struct owl_dma_txd *txd; 873 struct owl_dma_lli *lli, *prev = NULL; 874 size_t offset, bytes; 875 int ret; 876 877 if (!len) 878 return NULL; 879 880 txd = kzalloc(sizeof(*txd), GFP_NOWAIT); 881 if (!txd) 882 return NULL; 883 884 INIT_LIST_HEAD(&txd->lli_list); 885 886 /* Process the transfer as frame by frame */ 887 for (offset = 0; offset < len; offset += bytes) { 888 lli = owl_dma_alloc_lli(od); 889 if (!lli) { 890 dev_warn(chan2dev(chan), "failed to allocate lli\n"); 891 goto err_txd_free; 892 } 893 894 bytes = min_t(size_t, (len - offset), OWL_DMA_FRAME_MAX_LENGTH); 895 896 ret = owl_dma_cfg_lli(vchan, lli, src + offset, dst + offset, 897 bytes, DMA_MEM_TO_MEM, 898 &vchan->cfg, txd->cyclic); 899 if (ret) { 900 dev_warn(chan2dev(chan), "failed to config lli\n"); 901 goto err_txd_free; 902 } 903 904 prev = owl_dma_add_lli(txd, prev, lli, false); 905 } 906 907 return vchan_tx_prep(&vchan->vc, &txd->vd, flags); 908 909err_txd_free: 910 owl_dma_free_txd(od, txd); 911 return NULL; 912} 913 914static struct dma_async_tx_descriptor 915 *owl_dma_prep_slave_sg(struct dma_chan *chan, 916 struct scatterlist *sgl, 917 unsigned int sg_len, 918 enum dma_transfer_direction dir, 919 unsigned long flags, void *context) 920{ 921 struct owl_dma *od = to_owl_dma(chan->device); 922 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 923 struct dma_slave_config *sconfig = &vchan->cfg; 924 struct owl_dma_txd *txd; 925 struct owl_dma_lli *lli, *prev = NULL; 926 struct scatterlist *sg; 927 dma_addr_t addr, src = 0, dst = 0; 928 size_t len; 929 int ret, i; 930 931 txd = kzalloc(sizeof(*txd), GFP_NOWAIT); 932 if (!txd) 933 return NULL; 934 935 INIT_LIST_HEAD(&txd->lli_list); 936 937 for_each_sg(sgl, sg, sg_len, i) { 938 addr = sg_dma_address(sg); 939 len = sg_dma_len(sg); 940 941 if (len > OWL_DMA_FRAME_MAX_LENGTH) { 942 dev_err(od->dma.dev, 943 "frame length exceeds max supported length"); 944 goto err_txd_free; 945 } 946 947 lli = owl_dma_alloc_lli(od); 948 if (!lli) { 949 dev_err(chan2dev(chan), "failed to allocate lli"); 950 goto err_txd_free; 951 } 952 953 if (dir == DMA_MEM_TO_DEV) { 954 src = addr; 955 dst = sconfig->dst_addr; 956 } else { 957 src = sconfig->src_addr; 958 dst = addr; 959 } 960 961 ret = owl_dma_cfg_lli(vchan, lli, src, dst, len, dir, sconfig, 962 txd->cyclic); 963 if (ret) { 964 dev_warn(chan2dev(chan), "failed to config lli"); 965 goto err_txd_free; 966 } 967 968 prev = owl_dma_add_lli(txd, prev, lli, false); 969 } 970 971 return vchan_tx_prep(&vchan->vc, &txd->vd, flags); 972 973err_txd_free: 974 owl_dma_free_txd(od, txd); 975 976 return NULL; 977} 978 979static struct dma_async_tx_descriptor 980 *owl_prep_dma_cyclic(struct dma_chan *chan, 981 dma_addr_t buf_addr, size_t buf_len, 982 size_t period_len, 983 enum dma_transfer_direction dir, 984 unsigned long flags) 985{ 986 struct owl_dma *od = to_owl_dma(chan->device); 987 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 988 struct dma_slave_config *sconfig = &vchan->cfg; 989 struct owl_dma_txd *txd; 990 struct owl_dma_lli *lli, *prev = NULL, *first = NULL; 991 dma_addr_t src = 0, dst = 0; 992 unsigned int periods = buf_len / period_len; 993 int ret, i; 994 995 txd = kzalloc(sizeof(*txd), GFP_NOWAIT); 996 if (!txd) 997 return NULL; 998 999 INIT_LIST_HEAD(&txd->lli_list); 1000 txd->cyclic = true; 1001 1002 for (i = 0; i < periods; i++) { 1003 lli = owl_dma_alloc_lli(od); 1004 if (!lli) { 1005 dev_warn(chan2dev(chan), "failed to allocate lli"); 1006 goto err_txd_free; 1007 } 1008 1009 if (dir == DMA_MEM_TO_DEV) { 1010 src = buf_addr + (period_len * i); 1011 dst = sconfig->dst_addr; 1012 } else if (dir == DMA_DEV_TO_MEM) { 1013 src = sconfig->src_addr; 1014 dst = buf_addr + (period_len * i); 1015 } 1016 1017 ret = owl_dma_cfg_lli(vchan, lli, src, dst, period_len, 1018 dir, sconfig, txd->cyclic); 1019 if (ret) { 1020 dev_warn(chan2dev(chan), "failed to config lli"); 1021 goto err_txd_free; 1022 } 1023 1024 if (!first) 1025 first = lli; 1026 1027 prev = owl_dma_add_lli(txd, prev, lli, false); 1028 } 1029 1030 /* close the cyclic list */ 1031 owl_dma_add_lli(txd, prev, first, true); 1032 1033 return vchan_tx_prep(&vchan->vc, &txd->vd, flags); 1034 1035err_txd_free: 1036 owl_dma_free_txd(od, txd); 1037 1038 return NULL; 1039} 1040 1041static void owl_dma_free_chan_resources(struct dma_chan *chan) 1042{ 1043 struct owl_dma_vchan *vchan = to_owl_vchan(chan); 1044 1045 /* Ensure all queued descriptors are freed */ 1046 vchan_free_chan_resources(&vchan->vc); 1047} 1048 1049static inline void owl_dma_free(struct owl_dma *od) 1050{ 1051 struct owl_dma_vchan *vchan = NULL; 1052 struct owl_dma_vchan *next; 1053 1054 list_for_each_entry_safe(vchan, 1055 next, &od->dma.channels, vc.chan.device_node) { 1056 list_del(&vchan->vc.chan.device_node); 1057 tasklet_kill(&vchan->vc.task); 1058 } 1059} 1060 1061static struct dma_chan *owl_dma_of_xlate(struct of_phandle_args *dma_spec, 1062 struct of_dma *ofdma) 1063{ 1064 struct owl_dma *od = ofdma->of_dma_data; 1065 struct owl_dma_vchan *vchan; 1066 struct dma_chan *chan; 1067 u8 drq = dma_spec->args[0]; 1068 1069 if (drq > od->nr_vchans) 1070 return NULL; 1071 1072 chan = dma_get_any_slave_channel(&od->dma); 1073 if (!chan) 1074 return NULL; 1075 1076 vchan = to_owl_vchan(chan); 1077 vchan->drq = drq; 1078 1079 return chan; 1080} 1081 1082static const struct of_device_id owl_dma_match[] = { 1083 { .compatible = "actions,s900-dma", .data = (void *)S900_DMA,}, 1084 { .compatible = "actions,s700-dma", .data = (void *)S700_DMA,}, 1085 { /* sentinel */ }, 1086}; 1087MODULE_DEVICE_TABLE(of, owl_dma_match); 1088 1089static int owl_dma_probe(struct platform_device *pdev) 1090{ 1091 struct device_node *np = pdev->dev.of_node; 1092 struct owl_dma *od; 1093 int ret, i, nr_channels, nr_requests; 1094 1095 od = devm_kzalloc(&pdev->dev, sizeof(*od), GFP_KERNEL); 1096 if (!od) 1097 return -ENOMEM; 1098 1099 od->base = devm_platform_ioremap_resource(pdev, 0); 1100 if (IS_ERR(od->base)) 1101 return PTR_ERR(od->base); 1102 1103 ret = of_property_read_u32(np, "dma-channels", &nr_channels); 1104 if (ret) { 1105 dev_err(&pdev->dev, "can't get dma-channels\n"); 1106 return ret; 1107 } 1108 1109 ret = of_property_read_u32(np, "dma-requests", &nr_requests); 1110 if (ret) { 1111 dev_err(&pdev->dev, "can't get dma-requests\n"); 1112 return ret; 1113 } 1114 1115 dev_info(&pdev->dev, "dma-channels %d, dma-requests %d\n", 1116 nr_channels, nr_requests); 1117 1118 od->devid = (enum owl_dma_id)of_device_get_match_data(&pdev->dev); 1119 1120 od->nr_pchans = nr_channels; 1121 od->nr_vchans = nr_requests; 1122 1123 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); 1124 1125 platform_set_drvdata(pdev, od); 1126 spin_lock_init(&od->lock); 1127 1128 dma_cap_set(DMA_MEMCPY, od->dma.cap_mask); 1129 dma_cap_set(DMA_SLAVE, od->dma.cap_mask); 1130 dma_cap_set(DMA_CYCLIC, od->dma.cap_mask); 1131 1132 od->dma.dev = &pdev->dev; 1133 od->dma.device_free_chan_resources = owl_dma_free_chan_resources; 1134 od->dma.device_tx_status = owl_dma_tx_status; 1135 od->dma.device_issue_pending = owl_dma_issue_pending; 1136 od->dma.device_prep_dma_memcpy = owl_dma_prep_memcpy; 1137 od->dma.device_prep_slave_sg = owl_dma_prep_slave_sg; 1138 od->dma.device_prep_dma_cyclic = owl_prep_dma_cyclic; 1139 od->dma.device_config = owl_dma_config; 1140 od->dma.device_pause = owl_dma_pause; 1141 od->dma.device_resume = owl_dma_resume; 1142 od->dma.device_terminate_all = owl_dma_terminate_all; 1143 od->dma.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 1144 od->dma.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 1145 od->dma.directions = BIT(DMA_MEM_TO_MEM); 1146 od->dma.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; 1147 1148 INIT_LIST_HEAD(&od->dma.channels); 1149 1150 od->clk = devm_clk_get(&pdev->dev, NULL); 1151 if (IS_ERR(od->clk)) { 1152 dev_err(&pdev->dev, "unable to get clock\n"); 1153 return PTR_ERR(od->clk); 1154 } 1155 1156 /* 1157 * Eventhough the DMA controller is capable of generating 4 1158 * IRQ's for DMA priority feature, we only use 1 IRQ for 1159 * simplification. 1160 */ 1161 od->irq = platform_get_irq(pdev, 0); 1162 ret = devm_request_irq(&pdev->dev, od->irq, owl_dma_interrupt, 0, 1163 dev_name(&pdev->dev), od); 1164 if (ret) { 1165 dev_err(&pdev->dev, "unable to request IRQ\n"); 1166 return ret; 1167 } 1168 1169 /* Init physical channel */ 1170 od->pchans = devm_kcalloc(&pdev->dev, od->nr_pchans, 1171 sizeof(struct owl_dma_pchan), GFP_KERNEL); 1172 if (!od->pchans) 1173 return -ENOMEM; 1174 1175 for (i = 0; i < od->nr_pchans; i++) { 1176 struct owl_dma_pchan *pchan = &od->pchans[i]; 1177 1178 pchan->id = i; 1179 pchan->base = od->base + OWL_DMA_CHAN_BASE(i); 1180 } 1181 1182 /* Init virtual channel */ 1183 od->vchans = devm_kcalloc(&pdev->dev, od->nr_vchans, 1184 sizeof(struct owl_dma_vchan), GFP_KERNEL); 1185 if (!od->vchans) 1186 return -ENOMEM; 1187 1188 for (i = 0; i < od->nr_vchans; i++) { 1189 struct owl_dma_vchan *vchan = &od->vchans[i]; 1190 1191 vchan->vc.desc_free = owl_dma_desc_free; 1192 vchan_init(&vchan->vc, &od->dma); 1193 } 1194 1195 /* Create a pool of consistent memory blocks for hardware descriptors */ 1196 od->lli_pool = dma_pool_create(dev_name(od->dma.dev), od->dma.dev, 1197 sizeof(struct owl_dma_lli), 1198 __alignof__(struct owl_dma_lli), 1199 0); 1200 if (!od->lli_pool) { 1201 dev_err(&pdev->dev, "unable to allocate DMA descriptor pool\n"); 1202 return -ENOMEM; 1203 } 1204 1205 clk_prepare_enable(od->clk); 1206 1207 ret = dma_async_device_register(&od->dma); 1208 if (ret) { 1209 dev_err(&pdev->dev, "failed to register DMA engine device\n"); 1210 goto err_pool_free; 1211 } 1212 1213 /* Device-tree DMA controller registration */ 1214 ret = of_dma_controller_register(pdev->dev.of_node, 1215 owl_dma_of_xlate, od); 1216 if (ret) { 1217 dev_err(&pdev->dev, "of_dma_controller_register failed\n"); 1218 goto err_dma_unregister; 1219 } 1220 1221 return 0; 1222 1223err_dma_unregister: 1224 dma_async_device_unregister(&od->dma); 1225err_pool_free: 1226 clk_disable_unprepare(od->clk); 1227 dma_pool_destroy(od->lli_pool); 1228 1229 return ret; 1230} 1231 1232static int owl_dma_remove(struct platform_device *pdev) 1233{ 1234 struct owl_dma *od = platform_get_drvdata(pdev); 1235 1236 of_dma_controller_free(pdev->dev.of_node); 1237 dma_async_device_unregister(&od->dma); 1238 1239 /* Mask all interrupts for this execution environment */ 1240 dma_writel(od, OWL_DMA_IRQ_EN0, 0x0); 1241 1242 /* Make sure we won't have any further interrupts */ 1243 devm_free_irq(od->dma.dev, od->irq, od); 1244 1245 owl_dma_free(od); 1246 1247 clk_disable_unprepare(od->clk); 1248 dma_pool_destroy(od->lli_pool); 1249 1250 return 0; 1251} 1252 1253static struct platform_driver owl_dma_driver = { 1254 .probe = owl_dma_probe, 1255 .remove = owl_dma_remove, 1256 .driver = { 1257 .name = "dma-owl", 1258 .of_match_table = of_match_ptr(owl_dma_match), 1259 }, 1260}; 1261 1262static int owl_dma_init(void) 1263{ 1264 return platform_driver_register(&owl_dma_driver); 1265} 1266subsys_initcall(owl_dma_init); 1267 1268static void __exit owl_dma_exit(void) 1269{ 1270 platform_driver_unregister(&owl_dma_driver); 1271} 1272module_exit(owl_dma_exit); 1273 1274MODULE_AUTHOR("David Liu <liuwei@actions-semi.com>"); 1275MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>"); 1276MODULE_DESCRIPTION("Actions Semi Owl SoCs DMA driver"); 1277MODULE_LICENSE("GPL"); 1278