1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Driver for the Atmel AHB DMA Controller (aka HDMA or DMAC on AT91 systems) 4 * 5 * Copyright (C) 2008 Atmel Corporation 6 * Copyright (C) 2022 Microchip Technology, Inc. and its subsidiaries 7 * 8 * This supports the Atmel AHB DMA Controller found in several Atmel SoCs. 9 * The only Atmel DMA Controller that is not covered by this driver is the one 10 * found on AT91SAM9263. 11 */ 12 13 #include <dt-bindings/dma/at91.h> 14 #include <linux/bitfield.h> 15 #include <linux/clk.h> 16 #include <linux/dmaengine.h> 17 #include <linux/dmapool.h> 18 #include <linux/dma-mapping.h> 19 #include <linux/interrupt.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/overflow.h> 23 #include <linux/of_platform.h> 24 #include <linux/of_dma.h> 25 #include <linux/platform_device.h> 26 #include <linux/slab.h> 27 28 #include "dmaengine.h" 29 #include "virt-dma.h" 30 31 /* 32 * Glossary 33 * -------- 34 * 35 * at_hdmac : Name of the ATmel AHB DMA Controller 36 * at_dma_ / atdma : ATmel DMA controller entity related 37 * atc_ / atchan : ATmel DMA Channel entity related 38 */ 39 40 #define AT_DMA_MAX_NR_CHANNELS 8 41 42 /* Global Configuration Register */ 43 #define AT_DMA_GCFG 0x00 44 #define AT_DMA_IF_BIGEND(i) BIT((i)) /* AHB-Lite Interface i in Big-endian mode */ 45 #define AT_DMA_ARB_CFG BIT(4) /* Arbiter mode. */ 46 47 /* Controller Enable Register */ 48 #define AT_DMA_EN 0x04 49 #define AT_DMA_ENABLE BIT(0) 50 51 /* Software Single Request Register */ 52 #define AT_DMA_SREQ 0x08 53 #define AT_DMA_SSREQ(x) BIT((x) << 1) /* Request a source single transfer on channel x */ 54 #define AT_DMA_DSREQ(x) BIT(1 + ((x) << 1)) /* Request a destination single transfer on channel x */ 55 56 /* Software Chunk Transfer Request Register */ 57 #define AT_DMA_CREQ 0x0c 58 #define AT_DMA_SCREQ(x) BIT((x) << 1) /* Request a source chunk transfer on channel x */ 59 #define AT_DMA_DCREQ(x) BIT(1 + ((x) << 1)) /* Request a destination chunk transfer on channel x */ 60 61 /* Software Last Transfer Flag Register */ 62 #define AT_DMA_LAST 0x10 63 #define AT_DMA_SLAST(x) BIT((x) << 1) /* This src rq is last tx of buffer on channel x */ 64 #define AT_DMA_DLAST(x) BIT(1 + ((x) << 1)) /* This dst rq is last tx of buffer on channel x */ 65 66 /* Request Synchronization Register */ 67 #define AT_DMA_SYNC 0x14 68 #define AT_DMA_SYR(h) BIT((h)) /* Synchronize handshake line h */ 69 70 /* Error, Chained Buffer transfer completed and Buffer transfer completed Interrupt registers */ 71 #define AT_DMA_EBCIER 0x18 /* Enable register */ 72 #define AT_DMA_EBCIDR 0x1c /* Disable register */ 73 #define AT_DMA_EBCIMR 0x20 /* Mask Register */ 74 #define AT_DMA_EBCISR 0x24 /* Status Register */ 75 #define AT_DMA_CBTC_OFFSET 8 76 #define AT_DMA_ERR_OFFSET 16 77 #define AT_DMA_BTC(x) BIT((x)) 78 #define AT_DMA_CBTC(x) BIT(AT_DMA_CBTC_OFFSET + (x)) 79 #define AT_DMA_ERR(x) BIT(AT_DMA_ERR_OFFSET + (x)) 80 81 /* Channel Handler Enable Register */ 82 #define AT_DMA_CHER 0x28 83 #define AT_DMA_ENA(x) BIT((x)) 84 #define AT_DMA_SUSP(x) BIT(8 + (x)) 85 #define AT_DMA_KEEP(x) BIT(24 + (x)) 86 87 /* Channel Handler Disable Register */ 88 #define AT_DMA_CHDR 0x2c 89 #define AT_DMA_DIS(x) BIT(x) 90 #define AT_DMA_RES(x) BIT(8 + (x)) 91 92 /* Channel Handler Status Register */ 93 #define AT_DMA_CHSR 0x30 94 #define AT_DMA_EMPT(x) BIT(16 + (x)) 95 #define AT_DMA_STAL(x) BIT(24 + (x)) 96 97 /* Channel registers base address */ 98 #define AT_DMA_CH_REGS_BASE 0x3c 99 #define ch_regs(x) (AT_DMA_CH_REGS_BASE + (x) * 0x28) /* Channel x base addr */ 100 101 /* Hardware register offset for each channel */ 102 #define ATC_SADDR_OFFSET 0x00 /* Source Address Register */ 103 #define ATC_DADDR_OFFSET 0x04 /* Destination Address Register */ 104 #define ATC_DSCR_OFFSET 0x08 /* Descriptor Address Register */ 105 #define ATC_CTRLA_OFFSET 0x0c /* Control A Register */ 106 #define ATC_CTRLB_OFFSET 0x10 /* Control B Register */ 107 #define ATC_CFG_OFFSET 0x14 /* Configuration Register */ 108 #define ATC_SPIP_OFFSET 0x18 /* Src PIP Configuration Register */ 109 #define ATC_DPIP_OFFSET 0x1c /* Dst PIP Configuration Register */ 110 111 112 /* Bitfield definitions */ 113 114 /* Bitfields in DSCR */ 115 #define ATC_DSCR_IF GENMASK(1, 0) /* Dsc feched via AHB-Lite Interface */ 116 117 /* Bitfields in CTRLA */ 118 #define ATC_BTSIZE_MAX GENMASK(15, 0) /* Maximum Buffer Transfer Size */ 119 #define ATC_BTSIZE GENMASK(15, 0) /* Buffer Transfer Size */ 120 #define ATC_SCSIZE GENMASK(18, 16) /* Source Chunk Transfer Size */ 121 #define ATC_DCSIZE GENMASK(22, 20) /* Destination Chunk Transfer Size */ 122 #define ATC_SRC_WIDTH GENMASK(25, 24) /* Source Single Transfer Size */ 123 #define ATC_DST_WIDTH GENMASK(29, 28) /* Destination Single Transfer Size */ 124 #define ATC_DONE BIT(31) /* Tx Done (only written back in descriptor) */ 125 126 /* Bitfields in CTRLB */ 127 #define ATC_SIF GENMASK(1, 0) /* Src tx done via AHB-Lite Interface i */ 128 #define ATC_DIF GENMASK(5, 4) /* Dst tx done via AHB-Lite Interface i */ 129 #define AT_DMA_MEM_IF 0x0 /* interface 0 as memory interface */ 130 #define AT_DMA_PER_IF 0x1 /* interface 1 as peripheral interface */ 131 #define ATC_SRC_PIP BIT(8) /* Source Picture-in-Picture enabled */ 132 #define ATC_DST_PIP BIT(12) /* Destination Picture-in-Picture enabled */ 133 #define ATC_SRC_DSCR_DIS BIT(16) /* Src Descriptor fetch disable */ 134 #define ATC_DST_DSCR_DIS BIT(20) /* Dst Descriptor fetch disable */ 135 #define ATC_FC GENMASK(23, 21) /* Choose Flow Controller */ 136 #define ATC_FC_MEM2MEM 0x0 /* Mem-to-Mem (DMA) */ 137 #define ATC_FC_MEM2PER 0x1 /* Mem-to-Periph (DMA) */ 138 #define ATC_FC_PER2MEM 0x2 /* Periph-to-Mem (DMA) */ 139 #define ATC_FC_PER2PER 0x3 /* Periph-to-Periph (DMA) */ 140 #define ATC_FC_PER2MEM_PER 0x4 /* Periph-to-Mem (Peripheral) */ 141 #define ATC_FC_MEM2PER_PER 0x5 /* Mem-to-Periph (Peripheral) */ 142 #define ATC_FC_PER2PER_SRCPER 0x6 /* Periph-to-Periph (Src Peripheral) */ 143 #define ATC_FC_PER2PER_DSTPER 0x7 /* Periph-to-Periph (Dst Peripheral) */ 144 #define ATC_SRC_ADDR_MODE GENMASK(25, 24) 145 #define ATC_SRC_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ 146 #define ATC_SRC_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ 147 #define ATC_SRC_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ 148 #define ATC_DST_ADDR_MODE GENMASK(29, 28) 149 #define ATC_DST_ADDR_MODE_INCR 0x0 /* Incrementing Mode */ 150 #define ATC_DST_ADDR_MODE_DECR 0x1 /* Decrementing Mode */ 151 #define ATC_DST_ADDR_MODE_FIXED 0x2 /* Fixed Mode */ 152 #define ATC_IEN BIT(30) /* BTC interrupt enable (active low) */ 153 #define ATC_AUTO BIT(31) /* Auto multiple buffer tx enable */ 154 155 /* Bitfields in CFG */ 156 #define ATC_SRC_PER GENMASK(3, 0) /* Channel src rq associated with periph handshaking ifc h */ 157 #define ATC_DST_PER GENMASK(7, 4) /* Channel dst rq associated with periph handshaking ifc h */ 158 #define ATC_SRC_REP BIT(8) /* Source Replay Mod */ 159 #define ATC_SRC_H2SEL BIT(9) /* Source Handshaking Mod */ 160 #define ATC_SRC_PER_MSB GENMASK(11, 10) /* Channel src rq (most significant bits) */ 161 #define ATC_DST_REP BIT(12) /* Destination Replay Mod */ 162 #define ATC_DST_H2SEL BIT(13) /* Destination Handshaking Mod */ 163 #define ATC_DST_PER_MSB GENMASK(15, 14) /* Channel dst rq (most significant bits) */ 164 #define ATC_SOD BIT(16) /* Stop On Done */ 165 #define ATC_LOCK_IF BIT(20) /* Interface Lock */ 166 #define ATC_LOCK_B BIT(21) /* AHB Bus Lock */ 167 #define ATC_LOCK_IF_L BIT(22) /* Master Interface Arbiter Lock */ 168 #define ATC_AHB_PROT GENMASK(26, 24) /* AHB Protection */ 169 #define ATC_FIFOCFG GENMASK(29, 28) /* FIFO Request Configuration */ 170 #define ATC_FIFOCFG_LARGESTBURST 0x0 171 #define ATC_FIFOCFG_HALFFIFO 0x1 172 #define ATC_FIFOCFG_ENOUGHSPACE 0x2 173 174 /* Bitfields in SPIP */ 175 #define ATC_SPIP_HOLE GENMASK(15, 0) 176 #define ATC_SPIP_BOUNDARY GENMASK(25, 16) 177 178 /* Bitfields in DPIP */ 179 #define ATC_DPIP_HOLE GENMASK(15, 0) 180 #define ATC_DPIP_BOUNDARY GENMASK(25, 16) 181 182 #define ATC_PER_MSB GENMASK(5, 4) /* Extract MSBs of a handshaking identifier */ 183 #define ATC_SRC_PER_ID(id) \ 184 ({ typeof(id) _id = (id); \ 185 FIELD_PREP(ATC_SRC_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ 186 FIELD_PREP(ATC_SRC_PER, _id); }) 187 #define ATC_DST_PER_ID(id) \ 188 ({ typeof(id) _id = (id); \ 189 FIELD_PREP(ATC_DST_PER_MSB, FIELD_GET(ATC_PER_MSB, _id)) | \ 190 FIELD_PREP(ATC_DST_PER, _id); }) 191 192 193 194 /*-- descriptors -----------------------------------------------------*/ 195 196 /* LLI == Linked List Item; aka DMA buffer descriptor */ 197 struct at_lli { 198 /* values that are not changed by hardware */ 199 u32 saddr; 200 u32 daddr; 201 /* value that may get written back: */ 202 u32 ctrla; 203 /* more values that are not changed by hardware */ 204 u32 ctrlb; 205 u32 dscr; /* chain to next lli */ 206 }; 207 208 /** 209 * struct atdma_sg - atdma scatter gather entry 210 * @len: length of the current Linked List Item. 211 * @lli: linked list item that is passed to the DMA controller 212 * @lli_phys: physical address of the LLI. 213 */ 214 struct atdma_sg { 215 unsigned int len; 216 struct at_lli *lli; 217 dma_addr_t lli_phys; 218 }; 219 220 /** 221 * struct at_desc - software descriptor 222 * @vd: pointer to the virtual dma descriptor. 223 * @atchan: pointer to the atmel dma channel. 224 * @total_len: total transaction byte count 225 * @sg_len: number of sg entries. 226 * @sg: array of sgs. 227 */ 228 struct at_desc { 229 struct virt_dma_desc vd; 230 struct at_dma_chan *atchan; 231 size_t total_len; 232 unsigned int sglen; 233 /* Interleaved data */ 234 size_t boundary; 235 size_t dst_hole; 236 size_t src_hole; 237 238 /* Memset temporary buffer */ 239 bool memset_buffer; 240 dma_addr_t memset_paddr; 241 int *memset_vaddr; 242 struct atdma_sg sg[] __counted_by(sglen); 243 }; 244 245 /*-- Channels --------------------------------------------------------*/ 246 247 /** 248 * atc_status - information bits stored in channel status flag 249 * 250 * Manipulated with atomic operations. 251 */ 252 enum atc_status { 253 ATC_IS_PAUSED = 1, 254 ATC_IS_CYCLIC = 24, 255 }; 256 257 /** 258 * struct at_dma_chan - internal representation of an Atmel HDMAC channel 259 * @vc: virtual dma channel entry. 260 * @atdma: pointer to the driver data. 261 * @ch_regs: memory mapped register base 262 * @mask: channel index in a mask 263 * @per_if: peripheral interface 264 * @mem_if: memory interface 265 * @status: transmit status information from irq/prep* functions 266 * to tasklet (use atomic operations) 267 * @save_cfg: configuration register that is saved on suspend/resume cycle 268 * @save_dscr: for cyclic operations, preserve next descriptor address in 269 * the cyclic list on suspend/resume cycle 270 * @dma_sconfig: configuration for slave transfers, passed via 271 * .device_config 272 * @desc: pointer to the atmel dma descriptor. 273 */ 274 struct at_dma_chan { 275 struct virt_dma_chan vc; 276 struct at_dma *atdma; 277 void __iomem *ch_regs; 278 u8 mask; 279 u8 per_if; 280 u8 mem_if; 281 unsigned long status; 282 u32 save_cfg; 283 u32 save_dscr; 284 struct dma_slave_config dma_sconfig; 285 bool cyclic; 286 struct at_desc *desc; 287 }; 288 289 #define channel_readl(atchan, name) \ 290 __raw_readl((atchan)->ch_regs + ATC_##name##_OFFSET) 291 292 #define channel_writel(atchan, name, val) \ 293 __raw_writel((val), (atchan)->ch_regs + ATC_##name##_OFFSET) 294 295 /* 296 * Fix sconfig's burst size according to at_hdmac. We need to convert them as: 297 * 1 -> 0, 4 -> 1, 8 -> 2, 16 -> 3, 32 -> 4, 64 -> 5, 128 -> 6, 256 -> 7. 298 * 299 * This can be done by finding most significant bit set. 300 */ 301 static inline void convert_burst(u32 *maxburst) 302 { 303 if (*maxburst > 1) 304 *maxburst = fls(*maxburst) - 2; 305 else 306 *maxburst = 0; 307 } 308 309 /* 310 * Fix sconfig's bus width according to at_hdmac. 311 * 1 byte -> 0, 2 bytes -> 1, 4 bytes -> 2. 312 */ 313 static inline u8 convert_buswidth(enum dma_slave_buswidth addr_width) 314 { 315 switch (addr_width) { 316 case DMA_SLAVE_BUSWIDTH_2_BYTES: 317 return 1; 318 case DMA_SLAVE_BUSWIDTH_4_BYTES: 319 return 2; 320 default: 321 /* For 1 byte width or fallback */ 322 return 0; 323 } 324 } 325 326 /*-- Controller ------------------------------------------------------*/ 327 328 /** 329 * struct at_dma - internal representation of an Atmel HDMA Controller 330 * @dma_device: dmaengine dma_device object members 331 * @atdma_devtype: identifier of DMA controller compatibility 332 * @ch_regs: memory mapped register base 333 * @clk: dma controller clock 334 * @save_imr: interrupt mask register that is saved on suspend/resume cycle 335 * @all_chan_mask: all channels availlable in a mask 336 * @lli_pool: hw lli table 337 * @chan: channels table to store at_dma_chan structures 338 */ 339 struct at_dma { 340 struct dma_device dma_device; 341 void __iomem *regs; 342 struct clk *clk; 343 u32 save_imr; 344 345 u8 all_chan_mask; 346 347 struct dma_pool *lli_pool; 348 struct dma_pool *memset_pool; 349 /* AT THE END channels table */ 350 struct at_dma_chan chan[]; 351 }; 352 353 #define dma_readl(atdma, name) \ 354 __raw_readl((atdma)->regs + AT_DMA_##name) 355 #define dma_writel(atdma, name, val) \ 356 __raw_writel((val), (atdma)->regs + AT_DMA_##name) 357 358 static inline struct at_desc *to_atdma_desc(struct dma_async_tx_descriptor *t) 359 { 360 return container_of(t, struct at_desc, vd.tx); 361 } 362 363 static inline struct at_dma_chan *to_at_dma_chan(struct dma_chan *chan) 364 { 365 return container_of(chan, struct at_dma_chan, vc.chan); 366 } 367 368 static inline struct at_dma *to_at_dma(struct dma_device *ddev) 369 { 370 return container_of(ddev, struct at_dma, dma_device); 371 } 372 373 374 /*-- Helper functions ------------------------------------------------*/ 375 376 static struct device *chan2dev(struct dma_chan *chan) 377 { 378 return &chan->dev->device; 379 } 380 381 #if defined(VERBOSE_DEBUG) 382 static void vdbg_dump_regs(struct at_dma_chan *atchan) 383 { 384 struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); 385 386 dev_err(chan2dev(&atchan->vc.chan), 387 " channel %d : imr = 0x%x, chsr = 0x%x\n", 388 atchan->vc.chan.chan_id, 389 dma_readl(atdma, EBCIMR), 390 dma_readl(atdma, CHSR)); 391 392 dev_err(chan2dev(&atchan->vc.chan), 393 " channel: s0x%x d0x%x ctrl0x%x:0x%x cfg0x%x l0x%x\n", 394 channel_readl(atchan, SADDR), 395 channel_readl(atchan, DADDR), 396 channel_readl(atchan, CTRLA), 397 channel_readl(atchan, CTRLB), 398 channel_readl(atchan, CFG), 399 channel_readl(atchan, DSCR)); 400 } 401 #else 402 static void vdbg_dump_regs(struct at_dma_chan *atchan) {} 403 #endif 404 405 static void atc_dump_lli(struct at_dma_chan *atchan, struct at_lli *lli) 406 { 407 dev_crit(chan2dev(&atchan->vc.chan), 408 "desc: s%pad d%pad ctrl0x%x:0x%x l%pad\n", 409 &lli->saddr, &lli->daddr, 410 lli->ctrla, lli->ctrlb, &lli->dscr); 411 } 412 413 414 static void atc_setup_irq(struct at_dma *atdma, int chan_id, int on) 415 { 416 u32 ebci; 417 418 /* enable interrupts on buffer transfer completion & error */ 419 ebci = AT_DMA_BTC(chan_id) 420 | AT_DMA_ERR(chan_id); 421 if (on) 422 dma_writel(atdma, EBCIER, ebci); 423 else 424 dma_writel(atdma, EBCIDR, ebci); 425 } 426 427 static void atc_enable_chan_irq(struct at_dma *atdma, int chan_id) 428 { 429 atc_setup_irq(atdma, chan_id, 1); 430 } 431 432 static void atc_disable_chan_irq(struct at_dma *atdma, int chan_id) 433 { 434 atc_setup_irq(atdma, chan_id, 0); 435 } 436 437 438 /** 439 * atc_chan_is_enabled - test if given channel is enabled 440 * @atchan: channel we want to test status 441 */ 442 static inline int atc_chan_is_enabled(struct at_dma_chan *atchan) 443 { 444 struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); 445 446 return !!(dma_readl(atdma, CHSR) & atchan->mask); 447 } 448 449 /** 450 * atc_chan_is_paused - test channel pause/resume status 451 * @atchan: channel we want to test status 452 */ 453 static inline int atc_chan_is_paused(struct at_dma_chan *atchan) 454 { 455 return test_bit(ATC_IS_PAUSED, &atchan->status); 456 } 457 458 /** 459 * atc_chan_is_cyclic - test if given channel has cyclic property set 460 * @atchan: channel we want to test status 461 */ 462 static inline int atc_chan_is_cyclic(struct at_dma_chan *atchan) 463 { 464 return test_bit(ATC_IS_CYCLIC, &atchan->status); 465 } 466 467 /** 468 * set_lli_eol - set end-of-link to descriptor so it will end transfer 469 * @desc: descriptor, signle or at the end of a chain, to end chain on 470 * @i: index of the atmel scatter gather entry that is at the end of the chain. 471 */ 472 static void set_lli_eol(struct at_desc *desc, unsigned int i) 473 { 474 u32 ctrlb = desc->sg[i].lli->ctrlb; 475 476 ctrlb &= ~ATC_IEN; 477 ctrlb |= ATC_SRC_DSCR_DIS | ATC_DST_DSCR_DIS; 478 479 desc->sg[i].lli->ctrlb = ctrlb; 480 desc->sg[i].lli->dscr = 0; 481 } 482 483 #define ATC_DEFAULT_CFG FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO) 484 #define ATC_DEFAULT_CTRLB (FIELD_PREP(ATC_SIF, AT_DMA_MEM_IF) | \ 485 FIELD_PREP(ATC_DIF, AT_DMA_MEM_IF)) 486 #define ATC_DMA_BUSWIDTHS\ 487 (BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) |\ 488 BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) |\ 489 BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) |\ 490 BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)) 491 492 #define ATC_MAX_DSCR_TRIALS 10 493 494 /* 495 * Initial number of descriptors to allocate for each channel. This could 496 * be increased during dma usage. 497 */ 498 static unsigned int init_nr_desc_per_channel = 64; 499 module_param(init_nr_desc_per_channel, uint, 0644); 500 MODULE_PARM_DESC(init_nr_desc_per_channel, 501 "initial descriptors per channel (default: 64)"); 502 503 /** 504 * struct at_dma_platform_data - Controller configuration parameters 505 * @nr_channels: Number of channels supported by hardware (max 8) 506 * @cap_mask: dma_capability flags supported by the platform 507 */ 508 struct at_dma_platform_data { 509 unsigned int nr_channels; 510 dma_cap_mask_t cap_mask; 511 }; 512 513 /** 514 * struct at_dma_slave - Controller-specific information about a slave 515 * @dma_dev: required DMA master device 516 * @cfg: Platform-specific initializer for the CFG register 517 */ 518 struct at_dma_slave { 519 struct device *dma_dev; 520 u32 cfg; 521 }; 522 523 static inline unsigned int atc_get_xfer_width(dma_addr_t src, dma_addr_t dst, 524 size_t len) 525 { 526 unsigned int width; 527 528 if (!((src | dst | len) & 3)) 529 width = 2; 530 else if (!((src | dst | len) & 1)) 531 width = 1; 532 else 533 width = 0; 534 535 return width; 536 } 537 538 static void atdma_lli_chain(struct at_desc *desc, unsigned int i) 539 { 540 struct atdma_sg *atdma_sg = &desc->sg[i]; 541 542 if (i) 543 desc->sg[i - 1].lli->dscr = atdma_sg->lli_phys; 544 } 545 546 /** 547 * atc_dostart - starts the DMA engine for real 548 * @atchan: the channel we want to start 549 */ 550 static void atc_dostart(struct at_dma_chan *atchan) 551 { 552 struct virt_dma_desc *vd = vchan_next_desc(&atchan->vc); 553 struct at_desc *desc; 554 555 if (!vd) { 556 atchan->desc = NULL; 557 return; 558 } 559 560 vdbg_dump_regs(atchan); 561 562 list_del(&vd->node); 563 atchan->desc = desc = to_atdma_desc(&vd->tx); 564 565 channel_writel(atchan, SADDR, 0); 566 channel_writel(atchan, DADDR, 0); 567 channel_writel(atchan, CTRLA, 0); 568 channel_writel(atchan, CTRLB, 0); 569 channel_writel(atchan, DSCR, desc->sg[0].lli_phys); 570 channel_writel(atchan, SPIP, 571 FIELD_PREP(ATC_SPIP_HOLE, desc->src_hole) | 572 FIELD_PREP(ATC_SPIP_BOUNDARY, desc->boundary)); 573 channel_writel(atchan, DPIP, 574 FIELD_PREP(ATC_DPIP_HOLE, desc->dst_hole) | 575 FIELD_PREP(ATC_DPIP_BOUNDARY, desc->boundary)); 576 577 /* Don't allow CPU to reorder channel enable. */ 578 wmb(); 579 dma_writel(atchan->atdma, CHER, atchan->mask); 580 581 vdbg_dump_regs(atchan); 582 } 583 584 static void atdma_desc_free(struct virt_dma_desc *vd) 585 { 586 struct at_dma *atdma = to_at_dma(vd->tx.chan->device); 587 struct at_desc *desc = to_atdma_desc(&vd->tx); 588 unsigned int i; 589 590 for (i = 0; i < desc->sglen; i++) { 591 if (desc->sg[i].lli) 592 dma_pool_free(atdma->lli_pool, desc->sg[i].lli, 593 desc->sg[i].lli_phys); 594 } 595 596 /* If the transfer was a memset, free our temporary buffer */ 597 if (desc->memset_buffer) { 598 dma_pool_free(atdma->memset_pool, desc->memset_vaddr, 599 desc->memset_paddr); 600 desc->memset_buffer = false; 601 } 602 603 kfree(desc); 604 } 605 606 /** 607 * atc_calc_bytes_left - calculates the number of bytes left according to the 608 * value read from CTRLA. 609 * 610 * @current_len: the number of bytes left before reading CTRLA 611 * @ctrla: the value of CTRLA 612 */ 613 static inline u32 atc_calc_bytes_left(u32 current_len, u32 ctrla) 614 { 615 u32 btsize = FIELD_GET(ATC_BTSIZE, ctrla); 616 u32 src_width = FIELD_GET(ATC_SRC_WIDTH, ctrla); 617 618 /* 619 * According to the datasheet, when reading the Control A Register 620 * (ctrla), the Buffer Transfer Size (btsize) bitfield refers to the 621 * number of transfers completed on the Source Interface. 622 * So btsize is always a number of source width transfers. 623 */ 624 return current_len - (btsize << src_width); 625 } 626 627 /** 628 * atc_get_llis_residue - Get residue for a hardware linked list transfer 629 * 630 * Calculate the residue by removing the length of the Linked List Item (LLI) 631 * already transferred from the total length. To get the current LLI we can use 632 * the value of the channel's DSCR register and compare it against the DSCR 633 * value of each LLI. 634 * 635 * The CTRLA register provides us with the amount of data already read from the 636 * source for the LLI. So we can compute a more accurate residue by also 637 * removing the number of bytes corresponding to this amount of data. 638 * 639 * However, the DSCR and CTRLA registers cannot be read both atomically. Hence a 640 * race condition may occur: the first read register may refer to one LLI 641 * whereas the second read may refer to a later LLI in the list because of the 642 * DMA transfer progression inbetween the two reads. 643 * 644 * One solution could have been to pause the DMA transfer, read the DSCR and 645 * CTRLA then resume the DMA transfer. Nonetheless, this approach presents some 646 * drawbacks: 647 * - If the DMA transfer is paused, RX overruns or TX underruns are more likey 648 * to occur depending on the system latency. Taking the USART driver as an 649 * example, it uses a cyclic DMA transfer to read data from the Receive 650 * Holding Register (RHR) to avoid RX overruns since the RHR is not protected 651 * by any FIFO on most Atmel SoCs. So pausing the DMA transfer to compute the 652 * residue would break the USART driver design. 653 * - The atc_pause() function masks interrupts but we'd rather avoid to do so 654 * for system latency purpose. 655 * 656 * Then we'd rather use another solution: the DSCR is read a first time, the 657 * CTRLA is read in turn, next the DSCR is read a second time. If the two 658 * consecutive read values of the DSCR are the same then we assume both refers 659 * to the very same LLI as well as the CTRLA value read inbetween does. For 660 * cyclic tranfers, the assumption is that a full loop is "not so fast". If the 661 * two DSCR values are different, we read again the CTRLA then the DSCR till two 662 * consecutive read values from DSCR are equal or till the maximum trials is 663 * reach. This algorithm is very unlikely not to find a stable value for DSCR. 664 * @atchan: pointer to an atmel hdmac channel. 665 * @desc: pointer to the descriptor for which the residue is calculated. 666 * @residue: residue to be set to dma_tx_state. 667 * Returns 0 on success, -errno otherwise. 668 */ 669 static int atc_get_llis_residue(struct at_dma_chan *atchan, 670 struct at_desc *desc, u32 *residue) 671 { 672 u32 len, ctrla, dscr; 673 unsigned int i; 674 675 len = desc->total_len; 676 dscr = channel_readl(atchan, DSCR); 677 rmb(); /* ensure DSCR is read before CTRLA */ 678 ctrla = channel_readl(atchan, CTRLA); 679 for (i = 0; i < ATC_MAX_DSCR_TRIALS; ++i) { 680 u32 new_dscr; 681 682 rmb(); /* ensure DSCR is read after CTRLA */ 683 new_dscr = channel_readl(atchan, DSCR); 684 685 /* 686 * If the DSCR register value has not changed inside the DMA 687 * controller since the previous read, we assume that both the 688 * dscr and ctrla values refers to the very same descriptor. 689 */ 690 if (likely(new_dscr == dscr)) 691 break; 692 693 /* 694 * DSCR has changed inside the DMA controller, so the previouly 695 * read value of CTRLA may refer to an already processed 696 * descriptor hence could be outdated. We need to update ctrla 697 * to match the current descriptor. 698 */ 699 dscr = new_dscr; 700 rmb(); /* ensure DSCR is read before CTRLA */ 701 ctrla = channel_readl(atchan, CTRLA); 702 } 703 if (unlikely(i == ATC_MAX_DSCR_TRIALS)) 704 return -ETIMEDOUT; 705 706 /* For the first descriptor we can be more accurate. */ 707 if (desc->sg[0].lli->dscr == dscr) { 708 *residue = atc_calc_bytes_left(len, ctrla); 709 return 0; 710 } 711 len -= desc->sg[0].len; 712 713 for (i = 1; i < desc->sglen; i++) { 714 if (desc->sg[i].lli && desc->sg[i].lli->dscr == dscr) 715 break; 716 len -= desc->sg[i].len; 717 } 718 719 /* 720 * For the current LLI in the chain we can calculate the remaining bytes 721 * using the channel's CTRLA register. 722 */ 723 *residue = atc_calc_bytes_left(len, ctrla); 724 return 0; 725 726 } 727 728 /** 729 * atc_get_residue - get the number of bytes residue for a cookie. 730 * The residue is passed by address and updated on success. 731 * @chan: DMA channel 732 * @cookie: transaction identifier to check status of 733 * @residue: residue to be updated. 734 * Return 0 on success, -errono otherwise. 735 */ 736 static int atc_get_residue(struct dma_chan *chan, dma_cookie_t cookie, 737 u32 *residue) 738 { 739 struct at_dma_chan *atchan = to_at_dma_chan(chan); 740 struct virt_dma_desc *vd; 741 struct at_desc *desc = NULL; 742 u32 len, ctrla; 743 744 vd = vchan_find_desc(&atchan->vc, cookie); 745 if (vd) 746 desc = to_atdma_desc(&vd->tx); 747 else if (atchan->desc && atchan->desc->vd.tx.cookie == cookie) 748 desc = atchan->desc; 749 750 if (!desc) 751 return -EINVAL; 752 753 if (desc->sg[0].lli->dscr) 754 /* hardware linked list transfer */ 755 return atc_get_llis_residue(atchan, desc, residue); 756 757 /* single transfer */ 758 len = desc->total_len; 759 ctrla = channel_readl(atchan, CTRLA); 760 *residue = atc_calc_bytes_left(len, ctrla); 761 return 0; 762 } 763 764 /** 765 * atc_handle_error - handle errors reported by DMA controller 766 * @atchan: channel where error occurs. 767 * @i: channel index 768 */ 769 static void atc_handle_error(struct at_dma_chan *atchan, unsigned int i) 770 { 771 struct at_desc *desc = atchan->desc; 772 773 /* Disable channel on AHB error */ 774 dma_writel(atchan->atdma, CHDR, AT_DMA_RES(i) | atchan->mask); 775 776 /* 777 * KERN_CRITICAL may seem harsh, but since this only happens 778 * when someone submits a bad physical address in a 779 * descriptor, we should consider ourselves lucky that the 780 * controller flagged an error instead of scribbling over 781 * random memory locations. 782 */ 783 dev_crit(chan2dev(&atchan->vc.chan), "Bad descriptor submitted for DMA!\n"); 784 dev_crit(chan2dev(&atchan->vc.chan), "cookie: %d\n", 785 desc->vd.tx.cookie); 786 for (i = 0; i < desc->sglen; i++) 787 atc_dump_lli(atchan, desc->sg[i].lli); 788 } 789 790 static void atdma_handle_chan_done(struct at_dma_chan *atchan, u32 pending, 791 unsigned int i) 792 { 793 struct at_desc *desc; 794 795 spin_lock(&atchan->vc.lock); 796 desc = atchan->desc; 797 798 if (desc) { 799 if (pending & AT_DMA_ERR(i)) { 800 atc_handle_error(atchan, i); 801 /* Pretend the descriptor completed successfully */ 802 } 803 804 if (atc_chan_is_cyclic(atchan)) { 805 vchan_cyclic_callback(&desc->vd); 806 } else { 807 vchan_cookie_complete(&desc->vd); 808 atchan->desc = NULL; 809 if (!(atc_chan_is_enabled(atchan))) 810 atc_dostart(atchan); 811 } 812 } 813 spin_unlock(&atchan->vc.lock); 814 } 815 816 static irqreturn_t at_dma_interrupt(int irq, void *dev_id) 817 { 818 struct at_dma *atdma = dev_id; 819 struct at_dma_chan *atchan; 820 int i; 821 u32 status, pending, imr; 822 int ret = IRQ_NONE; 823 824 do { 825 imr = dma_readl(atdma, EBCIMR); 826 status = dma_readl(atdma, EBCISR); 827 pending = status & imr; 828 829 if (!pending) 830 break; 831 832 dev_vdbg(atdma->dma_device.dev, 833 "interrupt: status = 0x%08x, 0x%08x, 0x%08x\n", 834 status, imr, pending); 835 836 for (i = 0; i < atdma->dma_device.chancnt; i++) { 837 atchan = &atdma->chan[i]; 838 if (!(pending & (AT_DMA_BTC(i) | AT_DMA_ERR(i)))) 839 continue; 840 atdma_handle_chan_done(atchan, pending, i); 841 ret = IRQ_HANDLED; 842 } 843 844 } while (pending); 845 846 return ret; 847 } 848 849 /*-- DMA Engine API --------------------------------------------------*/ 850 /** 851 * atc_prep_dma_interleaved - prepare memory to memory interleaved operation 852 * @chan: the channel to prepare operation on 853 * @xt: Interleaved transfer template 854 * @flags: tx descriptor status flags 855 */ 856 static struct dma_async_tx_descriptor * 857 atc_prep_dma_interleaved(struct dma_chan *chan, 858 struct dma_interleaved_template *xt, 859 unsigned long flags) 860 { 861 struct at_dma *atdma = to_at_dma(chan->device); 862 struct at_dma_chan *atchan = to_at_dma_chan(chan); 863 struct data_chunk *first; 864 struct atdma_sg *atdma_sg; 865 struct at_desc *desc; 866 struct at_lli *lli; 867 size_t xfer_count; 868 unsigned int dwidth; 869 u32 ctrla; 870 u32 ctrlb; 871 size_t len = 0; 872 int i; 873 874 if (unlikely(!xt || xt->numf != 1 || !xt->frame_size)) 875 return NULL; 876 877 first = xt->sgl; 878 879 dev_info(chan2dev(chan), 880 "%s: src=%pad, dest=%pad, numf=%d, frame_size=%d, flags=0x%lx\n", 881 __func__, &xt->src_start, &xt->dst_start, xt->numf, 882 xt->frame_size, flags); 883 884 /* 885 * The controller can only "skip" X bytes every Y bytes, so we 886 * need to make sure we are given a template that fit that 887 * description, ie a template with chunks that always have the 888 * same size, with the same ICGs. 889 */ 890 for (i = 0; i < xt->frame_size; i++) { 891 struct data_chunk *chunk = xt->sgl + i; 892 893 if ((chunk->size != xt->sgl->size) || 894 (dmaengine_get_dst_icg(xt, chunk) != dmaengine_get_dst_icg(xt, first)) || 895 (dmaengine_get_src_icg(xt, chunk) != dmaengine_get_src_icg(xt, first))) { 896 dev_err(chan2dev(chan), 897 "%s: the controller can transfer only identical chunks\n", 898 __func__); 899 return NULL; 900 } 901 902 len += chunk->size; 903 } 904 905 dwidth = atc_get_xfer_width(xt->src_start, xt->dst_start, len); 906 907 xfer_count = len >> dwidth; 908 if (xfer_count > ATC_BTSIZE_MAX) { 909 dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); 910 return NULL; 911 } 912 913 ctrla = FIELD_PREP(ATC_SRC_WIDTH, dwidth) | 914 FIELD_PREP(ATC_DST_WIDTH, dwidth); 915 916 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | 917 FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | 918 FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | 919 ATC_SRC_PIP | ATC_DST_PIP | 920 FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); 921 922 desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); 923 if (!desc) 924 return NULL; 925 desc->sglen = 1; 926 927 atdma_sg = desc->sg; 928 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, 929 &atdma_sg->lli_phys); 930 if (!atdma_sg->lli) { 931 kfree(desc); 932 return NULL; 933 } 934 lli = atdma_sg->lli; 935 936 lli->saddr = xt->src_start; 937 lli->daddr = xt->dst_start; 938 lli->ctrla = ctrla | xfer_count; 939 lli->ctrlb = ctrlb; 940 941 desc->boundary = first->size >> dwidth; 942 desc->dst_hole = (dmaengine_get_dst_icg(xt, first) >> dwidth) + 1; 943 desc->src_hole = (dmaengine_get_src_icg(xt, first) >> dwidth) + 1; 944 945 atdma_sg->len = len; 946 desc->total_len = len; 947 948 set_lli_eol(desc, 0); 949 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 950 } 951 952 /** 953 * atc_prep_dma_memcpy - prepare a memcpy operation 954 * @chan: the channel to prepare operation on 955 * @dest: operation virtual destination address 956 * @src: operation virtual source address 957 * @len: operation length 958 * @flags: tx descriptor status flags 959 */ 960 static struct dma_async_tx_descriptor * 961 atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src, 962 size_t len, unsigned long flags) 963 { 964 struct at_dma *atdma = to_at_dma(chan->device); 965 struct at_dma_chan *atchan = to_at_dma_chan(chan); 966 struct at_desc *desc = NULL; 967 size_t xfer_count; 968 size_t offset; 969 size_t sg_len; 970 unsigned int src_width; 971 unsigned int dst_width; 972 unsigned int i; 973 u32 ctrla; 974 u32 ctrlb; 975 976 dev_dbg(chan2dev(chan), "prep_dma_memcpy: d%pad s%pad l0x%zx f0x%lx\n", 977 &dest, &src, len, flags); 978 979 if (unlikely(!len)) { 980 dev_err(chan2dev(chan), "prep_dma_memcpy: length is zero!\n"); 981 return NULL; 982 } 983 984 sg_len = DIV_ROUND_UP(len, ATC_BTSIZE_MAX); 985 desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); 986 if (!desc) 987 return NULL; 988 desc->sglen = sg_len; 989 990 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | 991 FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | 992 FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | 993 FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); 994 995 /* 996 * We can be a lot more clever here, but this should take care 997 * of the most common optimization. 998 */ 999 src_width = dst_width = atc_get_xfer_width(src, dest, len); 1000 1001 ctrla = FIELD_PREP(ATC_SRC_WIDTH, src_width) | 1002 FIELD_PREP(ATC_DST_WIDTH, dst_width); 1003 1004 for (offset = 0, i = 0; offset < len; 1005 offset += xfer_count << src_width, i++) { 1006 struct atdma_sg *atdma_sg = &desc->sg[i]; 1007 struct at_lli *lli; 1008 1009 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, 1010 &atdma_sg->lli_phys); 1011 if (!atdma_sg->lli) 1012 goto err_desc_get; 1013 lli = atdma_sg->lli; 1014 1015 xfer_count = min_t(size_t, (len - offset) >> src_width, 1016 ATC_BTSIZE_MAX); 1017 1018 lli->saddr = src + offset; 1019 lli->daddr = dest + offset; 1020 lli->ctrla = ctrla | xfer_count; 1021 lli->ctrlb = ctrlb; 1022 1023 desc->sg[i].len = xfer_count << src_width; 1024 1025 atdma_lli_chain(desc, i); 1026 } 1027 1028 desc->total_len = len; 1029 1030 /* set end-of-link to the last link descriptor of list*/ 1031 set_lli_eol(desc, i - 1); 1032 1033 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 1034 1035 err_desc_get: 1036 atdma_desc_free(&desc->vd); 1037 return NULL; 1038 } 1039 1040 static int atdma_create_memset_lli(struct dma_chan *chan, 1041 struct atdma_sg *atdma_sg, 1042 dma_addr_t psrc, dma_addr_t pdst, size_t len) 1043 { 1044 struct at_dma *atdma = to_at_dma(chan->device); 1045 struct at_lli *lli; 1046 size_t xfer_count; 1047 u32 ctrla = FIELD_PREP(ATC_SRC_WIDTH, 2) | FIELD_PREP(ATC_DST_WIDTH, 2); 1048 u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN | 1049 FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_FIXED) | 1050 FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | 1051 FIELD_PREP(ATC_FC, ATC_FC_MEM2MEM); 1052 1053 xfer_count = len >> 2; 1054 if (xfer_count > ATC_BTSIZE_MAX) { 1055 dev_err(chan2dev(chan), "%s: buffer is too big\n", __func__); 1056 return -EINVAL; 1057 } 1058 1059 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_NOWAIT, 1060 &atdma_sg->lli_phys); 1061 if (!atdma_sg->lli) 1062 return -ENOMEM; 1063 lli = atdma_sg->lli; 1064 1065 lli->saddr = psrc; 1066 lli->daddr = pdst; 1067 lli->ctrla = ctrla | xfer_count; 1068 lli->ctrlb = ctrlb; 1069 1070 atdma_sg->len = len; 1071 1072 return 0; 1073 } 1074 1075 /** 1076 * atc_prep_dma_memset - prepare a memcpy operation 1077 * @chan: the channel to prepare operation on 1078 * @dest: operation virtual destination address 1079 * @value: value to set memory buffer to 1080 * @len: operation length 1081 * @flags: tx descriptor status flags 1082 */ 1083 static struct dma_async_tx_descriptor * 1084 atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value, 1085 size_t len, unsigned long flags) 1086 { 1087 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1088 struct at_dma *atdma = to_at_dma(chan->device); 1089 struct at_desc *desc; 1090 void __iomem *vaddr; 1091 dma_addr_t paddr; 1092 char fill_pattern; 1093 int ret; 1094 1095 dev_vdbg(chan2dev(chan), "%s: d%pad v0x%x l0x%zx f0x%lx\n", __func__, 1096 &dest, value, len, flags); 1097 1098 if (unlikely(!len)) { 1099 dev_dbg(chan2dev(chan), "%s: length is zero!\n", __func__); 1100 return NULL; 1101 } 1102 1103 if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { 1104 dev_dbg(chan2dev(chan), "%s: buffer is not aligned\n", 1105 __func__); 1106 return NULL; 1107 } 1108 1109 vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); 1110 if (!vaddr) { 1111 dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", 1112 __func__); 1113 return NULL; 1114 } 1115 1116 /* Only the first byte of value is to be used according to dmaengine */ 1117 fill_pattern = (char)value; 1118 1119 *(u32*)vaddr = (fill_pattern << 24) | 1120 (fill_pattern << 16) | 1121 (fill_pattern << 8) | 1122 fill_pattern; 1123 1124 desc = kzalloc(struct_size(desc, sg, 1), GFP_ATOMIC); 1125 if (!desc) 1126 goto err_free_buffer; 1127 desc->sglen = 1; 1128 1129 ret = atdma_create_memset_lli(chan, desc->sg, paddr, dest, len); 1130 if (ret) 1131 goto err_free_desc; 1132 1133 desc->memset_paddr = paddr; 1134 desc->memset_vaddr = vaddr; 1135 desc->memset_buffer = true; 1136 1137 desc->total_len = len; 1138 1139 /* set end-of-link on the descriptor */ 1140 set_lli_eol(desc, 0); 1141 1142 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 1143 1144 err_free_desc: 1145 kfree(desc); 1146 err_free_buffer: 1147 dma_pool_free(atdma->memset_pool, vaddr, paddr); 1148 return NULL; 1149 } 1150 1151 static struct dma_async_tx_descriptor * 1152 atc_prep_dma_memset_sg(struct dma_chan *chan, 1153 struct scatterlist *sgl, 1154 unsigned int sg_len, int value, 1155 unsigned long flags) 1156 { 1157 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1158 struct at_dma *atdma = to_at_dma(chan->device); 1159 struct at_desc *desc; 1160 struct scatterlist *sg; 1161 void __iomem *vaddr; 1162 dma_addr_t paddr; 1163 size_t total_len = 0; 1164 int i; 1165 int ret; 1166 1167 dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__, 1168 value, sg_len, flags); 1169 1170 if (unlikely(!sgl || !sg_len)) { 1171 dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n", 1172 __func__); 1173 return NULL; 1174 } 1175 1176 vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr); 1177 if (!vaddr) { 1178 dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n", 1179 __func__); 1180 return NULL; 1181 } 1182 *(u32*)vaddr = value; 1183 1184 desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); 1185 if (!desc) 1186 goto err_free_dma_buf; 1187 desc->sglen = sg_len; 1188 1189 for_each_sg(sgl, sg, sg_len, i) { 1190 dma_addr_t dest = sg_dma_address(sg); 1191 size_t len = sg_dma_len(sg); 1192 1193 dev_vdbg(chan2dev(chan), "%s: d%pad, l0x%zx\n", 1194 __func__, &dest, len); 1195 1196 if (!is_dma_fill_aligned(chan->device, dest, 0, len)) { 1197 dev_err(chan2dev(chan), "%s: buffer is not aligned\n", 1198 __func__); 1199 goto err_free_desc; 1200 } 1201 1202 ret = atdma_create_memset_lli(chan, &desc->sg[i], paddr, dest, 1203 len); 1204 if (ret) 1205 goto err_free_desc; 1206 1207 atdma_lli_chain(desc, i); 1208 total_len += len; 1209 } 1210 1211 desc->memset_paddr = paddr; 1212 desc->memset_vaddr = vaddr; 1213 desc->memset_buffer = true; 1214 1215 desc->total_len = total_len; 1216 1217 /* set end-of-link on the descriptor */ 1218 set_lli_eol(desc, i - 1); 1219 1220 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 1221 1222 err_free_desc: 1223 atdma_desc_free(&desc->vd); 1224 err_free_dma_buf: 1225 dma_pool_free(atdma->memset_pool, vaddr, paddr); 1226 return NULL; 1227 } 1228 1229 /** 1230 * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction 1231 * @chan: DMA channel 1232 * @sgl: scatterlist to transfer to/from 1233 * @sg_len: number of entries in @scatterlist 1234 * @direction: DMA direction 1235 * @flags: tx descriptor status flags 1236 * @context: transaction context (ignored) 1237 */ 1238 static struct dma_async_tx_descriptor * 1239 atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl, 1240 unsigned int sg_len, enum dma_transfer_direction direction, 1241 unsigned long flags, void *context) 1242 { 1243 struct at_dma *atdma = to_at_dma(chan->device); 1244 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1245 struct at_dma_slave *atslave = chan->private; 1246 struct dma_slave_config *sconfig = &atchan->dma_sconfig; 1247 struct at_desc *desc; 1248 u32 ctrla; 1249 u32 ctrlb; 1250 dma_addr_t reg; 1251 unsigned int reg_width; 1252 unsigned int mem_width; 1253 unsigned int i; 1254 struct scatterlist *sg; 1255 size_t total_len = 0; 1256 1257 dev_vdbg(chan2dev(chan), "prep_slave_sg (%d): %s f0x%lx\n", 1258 sg_len, 1259 direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", 1260 flags); 1261 1262 if (unlikely(!atslave || !sg_len)) { 1263 dev_dbg(chan2dev(chan), "prep_slave_sg: sg length is zero!\n"); 1264 return NULL; 1265 } 1266 1267 desc = kzalloc(struct_size(desc, sg, sg_len), GFP_ATOMIC); 1268 if (!desc) 1269 return NULL; 1270 desc->sglen = sg_len; 1271 1272 ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | 1273 FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst); 1274 ctrlb = ATC_IEN; 1275 1276 switch (direction) { 1277 case DMA_MEM_TO_DEV: 1278 reg_width = convert_buswidth(sconfig->dst_addr_width); 1279 ctrla |= FIELD_PREP(ATC_DST_WIDTH, reg_width); 1280 ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, 1281 ATC_DST_ADDR_MODE_FIXED) | 1282 FIELD_PREP(ATC_SRC_ADDR_MODE, ATC_SRC_ADDR_MODE_INCR) | 1283 FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | 1284 FIELD_PREP(ATC_SIF, atchan->mem_if) | 1285 FIELD_PREP(ATC_DIF, atchan->per_if); 1286 reg = sconfig->dst_addr; 1287 for_each_sg(sgl, sg, sg_len, i) { 1288 struct atdma_sg *atdma_sg = &desc->sg[i]; 1289 struct at_lli *lli; 1290 u32 len; 1291 u32 mem; 1292 1293 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, 1294 GFP_NOWAIT, 1295 &atdma_sg->lli_phys); 1296 if (!atdma_sg->lli) 1297 goto err_desc_get; 1298 lli = atdma_sg->lli; 1299 1300 mem = sg_dma_address(sg); 1301 len = sg_dma_len(sg); 1302 if (unlikely(!len)) { 1303 dev_dbg(chan2dev(chan), 1304 "prep_slave_sg: sg(%d) data length is zero\n", i); 1305 goto err; 1306 } 1307 mem_width = 2; 1308 if (unlikely(mem & 3 || len & 3)) 1309 mem_width = 0; 1310 1311 lli->saddr = mem; 1312 lli->daddr = reg; 1313 lli->ctrla = ctrla | 1314 FIELD_PREP(ATC_SRC_WIDTH, mem_width) | 1315 len >> mem_width; 1316 lli->ctrlb = ctrlb; 1317 1318 atdma_sg->len = len; 1319 total_len += len; 1320 1321 desc->sg[i].len = len; 1322 atdma_lli_chain(desc, i); 1323 } 1324 break; 1325 case DMA_DEV_TO_MEM: 1326 reg_width = convert_buswidth(sconfig->src_addr_width); 1327 ctrla |= FIELD_PREP(ATC_SRC_WIDTH, reg_width); 1328 ctrlb |= FIELD_PREP(ATC_DST_ADDR_MODE, ATC_DST_ADDR_MODE_INCR) | 1329 FIELD_PREP(ATC_SRC_ADDR_MODE, 1330 ATC_SRC_ADDR_MODE_FIXED) | 1331 FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | 1332 FIELD_PREP(ATC_SIF, atchan->per_if) | 1333 FIELD_PREP(ATC_DIF, atchan->mem_if); 1334 1335 reg = sconfig->src_addr; 1336 for_each_sg(sgl, sg, sg_len, i) { 1337 struct atdma_sg *atdma_sg = &desc->sg[i]; 1338 struct at_lli *lli; 1339 u32 len; 1340 u32 mem; 1341 1342 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, 1343 GFP_NOWAIT, 1344 &atdma_sg->lli_phys); 1345 if (!atdma_sg->lli) 1346 goto err_desc_get; 1347 lli = atdma_sg->lli; 1348 1349 mem = sg_dma_address(sg); 1350 len = sg_dma_len(sg); 1351 if (unlikely(!len)) { 1352 dev_dbg(chan2dev(chan), 1353 "prep_slave_sg: sg(%d) data length is zero\n", i); 1354 goto err; 1355 } 1356 mem_width = 2; 1357 if (unlikely(mem & 3 || len & 3)) 1358 mem_width = 0; 1359 1360 lli->saddr = reg; 1361 lli->daddr = mem; 1362 lli->ctrla = ctrla | 1363 FIELD_PREP(ATC_DST_WIDTH, mem_width) | 1364 len >> reg_width; 1365 lli->ctrlb = ctrlb; 1366 1367 desc->sg[i].len = len; 1368 total_len += len; 1369 1370 atdma_lli_chain(desc, i); 1371 } 1372 break; 1373 default: 1374 return NULL; 1375 } 1376 1377 /* set end-of-link to the last link descriptor of list*/ 1378 set_lli_eol(desc, i - 1); 1379 1380 desc->total_len = total_len; 1381 1382 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 1383 1384 err_desc_get: 1385 dev_err(chan2dev(chan), "not enough descriptors available\n"); 1386 err: 1387 atdma_desc_free(&desc->vd); 1388 return NULL; 1389 } 1390 1391 /* 1392 * atc_dma_cyclic_check_values 1393 * Check for too big/unaligned periods and unaligned DMA buffer 1394 */ 1395 static int 1396 atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr, 1397 size_t period_len) 1398 { 1399 if (period_len > (ATC_BTSIZE_MAX << reg_width)) 1400 goto err_out; 1401 if (unlikely(period_len & ((1 << reg_width) - 1))) 1402 goto err_out; 1403 if (unlikely(buf_addr & ((1 << reg_width) - 1))) 1404 goto err_out; 1405 1406 return 0; 1407 1408 err_out: 1409 return -EINVAL; 1410 } 1411 1412 /* 1413 * atc_dma_cyclic_fill_desc - Fill one period descriptor 1414 */ 1415 static int 1416 atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc, 1417 unsigned int i, dma_addr_t buf_addr, 1418 unsigned int reg_width, size_t period_len, 1419 enum dma_transfer_direction direction) 1420 { 1421 struct at_dma *atdma = to_at_dma(chan->device); 1422 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1423 struct dma_slave_config *sconfig = &atchan->dma_sconfig; 1424 struct atdma_sg *atdma_sg = &desc->sg[i]; 1425 struct at_lli *lli; 1426 1427 atdma_sg->lli = dma_pool_alloc(atdma->lli_pool, GFP_ATOMIC, 1428 &atdma_sg->lli_phys); 1429 if (!atdma_sg->lli) 1430 return -ENOMEM; 1431 lli = atdma_sg->lli; 1432 1433 switch (direction) { 1434 case DMA_MEM_TO_DEV: 1435 lli->saddr = buf_addr + (period_len * i); 1436 lli->daddr = sconfig->dst_addr; 1437 lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, 1438 ATC_DST_ADDR_MODE_FIXED) | 1439 FIELD_PREP(ATC_SRC_ADDR_MODE, 1440 ATC_SRC_ADDR_MODE_INCR) | 1441 FIELD_PREP(ATC_FC, ATC_FC_MEM2PER) | 1442 FIELD_PREP(ATC_SIF, atchan->mem_if) | 1443 FIELD_PREP(ATC_DIF, atchan->per_if); 1444 1445 break; 1446 1447 case DMA_DEV_TO_MEM: 1448 lli->saddr = sconfig->src_addr; 1449 lli->daddr = buf_addr + (period_len * i); 1450 lli->ctrlb = FIELD_PREP(ATC_DST_ADDR_MODE, 1451 ATC_DST_ADDR_MODE_INCR) | 1452 FIELD_PREP(ATC_SRC_ADDR_MODE, 1453 ATC_SRC_ADDR_MODE_FIXED) | 1454 FIELD_PREP(ATC_FC, ATC_FC_PER2MEM) | 1455 FIELD_PREP(ATC_SIF, atchan->per_if) | 1456 FIELD_PREP(ATC_DIF, atchan->mem_if); 1457 break; 1458 1459 default: 1460 return -EINVAL; 1461 } 1462 1463 lli->ctrla = FIELD_PREP(ATC_SCSIZE, sconfig->src_maxburst) | 1464 FIELD_PREP(ATC_DCSIZE, sconfig->dst_maxburst) | 1465 FIELD_PREP(ATC_DST_WIDTH, reg_width) | 1466 FIELD_PREP(ATC_SRC_WIDTH, reg_width) | 1467 period_len >> reg_width; 1468 desc->sg[i].len = period_len; 1469 1470 return 0; 1471 } 1472 1473 /** 1474 * atc_prep_dma_cyclic - prepare the cyclic DMA transfer 1475 * @chan: the DMA channel to prepare 1476 * @buf_addr: physical DMA address where the buffer starts 1477 * @buf_len: total number of bytes for the entire buffer 1478 * @period_len: number of bytes for each period 1479 * @direction: transfer direction, to or from device 1480 * @flags: tx descriptor status flags 1481 */ 1482 static struct dma_async_tx_descriptor * 1483 atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len, 1484 size_t period_len, enum dma_transfer_direction direction, 1485 unsigned long flags) 1486 { 1487 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1488 struct at_dma_slave *atslave = chan->private; 1489 struct dma_slave_config *sconfig = &atchan->dma_sconfig; 1490 struct at_desc *desc; 1491 unsigned long was_cyclic; 1492 unsigned int reg_width; 1493 unsigned int periods = buf_len / period_len; 1494 unsigned int i; 1495 1496 dev_vdbg(chan2dev(chan), "prep_dma_cyclic: %s buf@%pad - %d (%d/%d)\n", 1497 direction == DMA_MEM_TO_DEV ? "TO DEVICE" : "FROM DEVICE", 1498 &buf_addr, 1499 periods, buf_len, period_len); 1500 1501 if (unlikely(!atslave || !buf_len || !period_len)) { 1502 dev_dbg(chan2dev(chan), "prep_dma_cyclic: length is zero!\n"); 1503 return NULL; 1504 } 1505 1506 was_cyclic = test_and_set_bit(ATC_IS_CYCLIC, &atchan->status); 1507 if (was_cyclic) { 1508 dev_dbg(chan2dev(chan), "prep_dma_cyclic: channel in use!\n"); 1509 return NULL; 1510 } 1511 1512 if (unlikely(!is_slave_direction(direction))) 1513 goto err_out; 1514 1515 if (direction == DMA_MEM_TO_DEV) 1516 reg_width = convert_buswidth(sconfig->dst_addr_width); 1517 else 1518 reg_width = convert_buswidth(sconfig->src_addr_width); 1519 1520 /* Check for too big/unaligned periods and unaligned DMA buffer */ 1521 if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len)) 1522 goto err_out; 1523 1524 desc = kzalloc(struct_size(desc, sg, periods), GFP_ATOMIC); 1525 if (!desc) 1526 goto err_out; 1527 desc->sglen = periods; 1528 1529 /* build cyclic linked list */ 1530 for (i = 0; i < periods; i++) { 1531 if (atc_dma_cyclic_fill_desc(chan, desc, i, buf_addr, 1532 reg_width, period_len, direction)) 1533 goto err_fill_desc; 1534 atdma_lli_chain(desc, i); 1535 } 1536 desc->total_len = buf_len; 1537 /* lets make a cyclic list */ 1538 desc->sg[i - 1].lli->dscr = desc->sg[0].lli_phys; 1539 1540 return vchan_tx_prep(&atchan->vc, &desc->vd, flags); 1541 1542 err_fill_desc: 1543 atdma_desc_free(&desc->vd); 1544 err_out: 1545 clear_bit(ATC_IS_CYCLIC, &atchan->status); 1546 return NULL; 1547 } 1548 1549 static int atc_config(struct dma_chan *chan, 1550 struct dma_slave_config *sconfig) 1551 { 1552 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1553 1554 dev_vdbg(chan2dev(chan), "%s\n", __func__); 1555 1556 /* Check if it is chan is configured for slave transfers */ 1557 if (!chan->private) 1558 return -EINVAL; 1559 1560 memcpy(&atchan->dma_sconfig, sconfig, sizeof(*sconfig)); 1561 1562 convert_burst(&atchan->dma_sconfig.src_maxburst); 1563 convert_burst(&atchan->dma_sconfig.dst_maxburst); 1564 1565 return 0; 1566 } 1567 1568 static int atc_pause(struct dma_chan *chan) 1569 { 1570 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1571 struct at_dma *atdma = to_at_dma(chan->device); 1572 int chan_id = atchan->vc.chan.chan_id; 1573 unsigned long flags; 1574 1575 dev_vdbg(chan2dev(chan), "%s\n", __func__); 1576 1577 spin_lock_irqsave(&atchan->vc.lock, flags); 1578 1579 dma_writel(atdma, CHER, AT_DMA_SUSP(chan_id)); 1580 set_bit(ATC_IS_PAUSED, &atchan->status); 1581 1582 spin_unlock_irqrestore(&atchan->vc.lock, flags); 1583 1584 return 0; 1585 } 1586 1587 static int atc_resume(struct dma_chan *chan) 1588 { 1589 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1590 struct at_dma *atdma = to_at_dma(chan->device); 1591 int chan_id = atchan->vc.chan.chan_id; 1592 unsigned long flags; 1593 1594 dev_vdbg(chan2dev(chan), "%s\n", __func__); 1595 1596 if (!atc_chan_is_paused(atchan)) 1597 return 0; 1598 1599 spin_lock_irqsave(&atchan->vc.lock, flags); 1600 1601 dma_writel(atdma, CHDR, AT_DMA_RES(chan_id)); 1602 clear_bit(ATC_IS_PAUSED, &atchan->status); 1603 1604 spin_unlock_irqrestore(&atchan->vc.lock, flags); 1605 1606 return 0; 1607 } 1608 1609 static int atc_terminate_all(struct dma_chan *chan) 1610 { 1611 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1612 struct at_dma *atdma = to_at_dma(chan->device); 1613 int chan_id = atchan->vc.chan.chan_id; 1614 unsigned long flags; 1615 1616 LIST_HEAD(list); 1617 1618 dev_vdbg(chan2dev(chan), "%s\n", __func__); 1619 1620 /* 1621 * This is only called when something went wrong elsewhere, so 1622 * we don't really care about the data. Just disable the 1623 * channel. We still have to poll the channel enable bit due 1624 * to AHB/HSB limitations. 1625 */ 1626 spin_lock_irqsave(&atchan->vc.lock, flags); 1627 1628 /* disabling channel: must also remove suspend state */ 1629 dma_writel(atdma, CHDR, AT_DMA_RES(chan_id) | atchan->mask); 1630 1631 /* confirm that this channel is disabled */ 1632 while (dma_readl(atdma, CHSR) & atchan->mask) 1633 cpu_relax(); 1634 1635 if (atchan->desc) { 1636 vchan_terminate_vdesc(&atchan->desc->vd); 1637 atchan->desc = NULL; 1638 } 1639 1640 vchan_get_all_descriptors(&atchan->vc, &list); 1641 1642 clear_bit(ATC_IS_PAUSED, &atchan->status); 1643 /* if channel dedicated to cyclic operations, free it */ 1644 clear_bit(ATC_IS_CYCLIC, &atchan->status); 1645 1646 spin_unlock_irqrestore(&atchan->vc.lock, flags); 1647 1648 vchan_dma_desc_free_list(&atchan->vc, &list); 1649 1650 return 0; 1651 } 1652 1653 /** 1654 * atc_tx_status - poll for transaction completion 1655 * @chan: DMA channel 1656 * @cookie: transaction identifier to check status of 1657 * @txstate: if not %NULL updated with transaction state 1658 * 1659 * If @txstate is passed in, upon return it reflect the driver 1660 * internal state and can be used with dma_async_is_complete() to check 1661 * the status of multiple cookies without re-checking hardware state. 1662 */ 1663 static enum dma_status 1664 atc_tx_status(struct dma_chan *chan, 1665 dma_cookie_t cookie, 1666 struct dma_tx_state *txstate) 1667 { 1668 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1669 unsigned long flags; 1670 enum dma_status dma_status; 1671 u32 residue; 1672 int ret; 1673 1674 dma_status = dma_cookie_status(chan, cookie, txstate); 1675 if (dma_status == DMA_COMPLETE || !txstate) 1676 return dma_status; 1677 1678 spin_lock_irqsave(&atchan->vc.lock, flags); 1679 /* Get number of bytes left in the active transactions */ 1680 ret = atc_get_residue(chan, cookie, &residue); 1681 spin_unlock_irqrestore(&atchan->vc.lock, flags); 1682 1683 if (unlikely(ret < 0)) { 1684 dev_vdbg(chan2dev(chan), "get residual bytes error\n"); 1685 return DMA_ERROR; 1686 } else { 1687 dma_set_residue(txstate, residue); 1688 } 1689 1690 dev_vdbg(chan2dev(chan), "tx_status %d: cookie = %d residue = %u\n", 1691 dma_status, cookie, residue); 1692 1693 return dma_status; 1694 } 1695 1696 static void atc_issue_pending(struct dma_chan *chan) 1697 { 1698 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1699 unsigned long flags; 1700 1701 spin_lock_irqsave(&atchan->vc.lock, flags); 1702 if (vchan_issue_pending(&atchan->vc) && !atchan->desc) { 1703 if (!(atc_chan_is_enabled(atchan))) 1704 atc_dostart(atchan); 1705 } 1706 spin_unlock_irqrestore(&atchan->vc.lock, flags); 1707 } 1708 1709 /** 1710 * atc_alloc_chan_resources - allocate resources for DMA channel 1711 * @chan: allocate descriptor resources for this channel 1712 * 1713 * return - the number of allocated descriptors 1714 */ 1715 static int atc_alloc_chan_resources(struct dma_chan *chan) 1716 { 1717 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1718 struct at_dma *atdma = to_at_dma(chan->device); 1719 struct at_dma_slave *atslave; 1720 u32 cfg; 1721 1722 dev_vdbg(chan2dev(chan), "alloc_chan_resources\n"); 1723 1724 /* ASSERT: channel is idle */ 1725 if (atc_chan_is_enabled(atchan)) { 1726 dev_dbg(chan2dev(chan), "DMA channel not idle ?\n"); 1727 return -EIO; 1728 } 1729 1730 cfg = ATC_DEFAULT_CFG; 1731 1732 atslave = chan->private; 1733 if (atslave) { 1734 /* 1735 * We need controller-specific data to set up slave 1736 * transfers. 1737 */ 1738 BUG_ON(!atslave->dma_dev || atslave->dma_dev != atdma->dma_device.dev); 1739 1740 /* if cfg configuration specified take it instead of default */ 1741 if (atslave->cfg) 1742 cfg = atslave->cfg; 1743 } 1744 1745 /* channel parameters */ 1746 channel_writel(atchan, CFG, cfg); 1747 1748 return 0; 1749 } 1750 1751 /** 1752 * atc_free_chan_resources - free all channel resources 1753 * @chan: DMA channel 1754 */ 1755 static void atc_free_chan_resources(struct dma_chan *chan) 1756 { 1757 struct at_dma_chan *atchan = to_at_dma_chan(chan); 1758 1759 BUG_ON(atc_chan_is_enabled(atchan)); 1760 1761 vchan_free_chan_resources(to_virt_chan(chan)); 1762 atchan->status = 0; 1763 1764 /* 1765 * Free atslave allocated in at_dma_xlate() 1766 */ 1767 kfree(chan->private); 1768 chan->private = NULL; 1769 1770 dev_vdbg(chan2dev(chan), "free_chan_resources: done\n"); 1771 } 1772 1773 #ifdef CONFIG_OF 1774 static bool at_dma_filter(struct dma_chan *chan, void *slave) 1775 { 1776 struct at_dma_slave *atslave = slave; 1777 1778 if (atslave->dma_dev == chan->device->dev) { 1779 chan->private = atslave; 1780 return true; 1781 } else { 1782 return false; 1783 } 1784 } 1785 1786 static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, 1787 struct of_dma *of_dma) 1788 { 1789 struct dma_chan *chan; 1790 struct at_dma_chan *atchan; 1791 struct at_dma_slave *atslave; 1792 dma_cap_mask_t mask; 1793 unsigned int per_id; 1794 struct platform_device *dmac_pdev; 1795 1796 if (dma_spec->args_count != 2) 1797 return NULL; 1798 1799 dmac_pdev = of_find_device_by_node(dma_spec->np); 1800 if (!dmac_pdev) 1801 return NULL; 1802 1803 dma_cap_zero(mask); 1804 dma_cap_set(DMA_SLAVE, mask); 1805 1806 atslave = kmalloc(sizeof(*atslave), GFP_KERNEL); 1807 if (!atslave) { 1808 put_device(&dmac_pdev->dev); 1809 return NULL; 1810 } 1811 1812 atslave->cfg = ATC_DST_H2SEL | ATC_SRC_H2SEL; 1813 /* 1814 * We can fill both SRC_PER and DST_PER, one of these fields will be 1815 * ignored depending on DMA transfer direction. 1816 */ 1817 per_id = dma_spec->args[1] & AT91_DMA_CFG_PER_ID_MASK; 1818 atslave->cfg |= ATC_DST_PER_ID(per_id) | ATC_SRC_PER_ID(per_id); 1819 /* 1820 * We have to translate the value we get from the device tree since 1821 * the half FIFO configuration value had to be 0 to keep backward 1822 * compatibility. 1823 */ 1824 switch (dma_spec->args[1] & AT91_DMA_CFG_FIFOCFG_MASK) { 1825 case AT91_DMA_CFG_FIFOCFG_ALAP: 1826 atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, 1827 ATC_FIFOCFG_LARGESTBURST); 1828 break; 1829 case AT91_DMA_CFG_FIFOCFG_ASAP: 1830 atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, 1831 ATC_FIFOCFG_ENOUGHSPACE); 1832 break; 1833 case AT91_DMA_CFG_FIFOCFG_HALF: 1834 default: 1835 atslave->cfg |= FIELD_PREP(ATC_FIFOCFG, ATC_FIFOCFG_HALFFIFO); 1836 } 1837 atslave->dma_dev = &dmac_pdev->dev; 1838 1839 chan = dma_request_channel(mask, at_dma_filter, atslave); 1840 if (!chan) { 1841 put_device(&dmac_pdev->dev); 1842 kfree(atslave); 1843 return NULL; 1844 } 1845 1846 atchan = to_at_dma_chan(chan); 1847 atchan->per_if = dma_spec->args[0] & 0xff; 1848 atchan->mem_if = (dma_spec->args[0] >> 16) & 0xff; 1849 1850 return chan; 1851 } 1852 #else 1853 static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec, 1854 struct of_dma *of_dma) 1855 { 1856 return NULL; 1857 } 1858 #endif 1859 1860 /*-- Module Management -----------------------------------------------*/ 1861 1862 /* cap_mask is a multi-u32 bitfield, fill it with proper C code. */ 1863 static struct at_dma_platform_data at91sam9rl_config = { 1864 .nr_channels = 2, 1865 }; 1866 static struct at_dma_platform_data at91sam9g45_config = { 1867 .nr_channels = 8, 1868 }; 1869 1870 #if defined(CONFIG_OF) 1871 static const struct of_device_id atmel_dma_dt_ids[] = { 1872 { 1873 .compatible = "atmel,at91sam9rl-dma", 1874 .data = &at91sam9rl_config, 1875 }, { 1876 .compatible = "atmel,at91sam9g45-dma", 1877 .data = &at91sam9g45_config, 1878 }, { 1879 /* sentinel */ 1880 } 1881 }; 1882 1883 MODULE_DEVICE_TABLE(of, atmel_dma_dt_ids); 1884 #endif 1885 1886 static const struct platform_device_id atdma_devtypes[] = { 1887 { 1888 .name = "at91sam9rl_dma", 1889 .driver_data = (unsigned long) &at91sam9rl_config, 1890 }, { 1891 .name = "at91sam9g45_dma", 1892 .driver_data = (unsigned long) &at91sam9g45_config, 1893 }, { 1894 /* sentinel */ 1895 } 1896 }; 1897 1898 static inline const struct at_dma_platform_data * __init at_dma_get_driver_data( 1899 struct platform_device *pdev) 1900 { 1901 if (pdev->dev.of_node) { 1902 const struct of_device_id *match; 1903 match = of_match_node(atmel_dma_dt_ids, pdev->dev.of_node); 1904 if (match == NULL) 1905 return NULL; 1906 return match->data; 1907 } 1908 return (struct at_dma_platform_data *) 1909 platform_get_device_id(pdev)->driver_data; 1910 } 1911 1912 /** 1913 * at_dma_off - disable DMA controller 1914 * @atdma: the Atmel HDAMC device 1915 */ 1916 static void at_dma_off(struct at_dma *atdma) 1917 { 1918 dma_writel(atdma, EN, 0); 1919 1920 /* disable all interrupts */ 1921 dma_writel(atdma, EBCIDR, -1L); 1922 1923 /* confirm that all channels are disabled */ 1924 while (dma_readl(atdma, CHSR) & atdma->all_chan_mask) 1925 cpu_relax(); 1926 } 1927 1928 static int __init at_dma_probe(struct platform_device *pdev) 1929 { 1930 struct at_dma *atdma; 1931 int irq; 1932 int err; 1933 int i; 1934 const struct at_dma_platform_data *plat_dat; 1935 1936 /* setup platform data for each SoC */ 1937 dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask); 1938 dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask); 1939 dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask); 1940 dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask); 1941 dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask); 1942 dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask); 1943 dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask); 1944 1945 /* get DMA parameters from controller type */ 1946 plat_dat = at_dma_get_driver_data(pdev); 1947 if (!plat_dat) 1948 return -ENODEV; 1949 1950 atdma = devm_kzalloc(&pdev->dev, 1951 struct_size(atdma, chan, plat_dat->nr_channels), 1952 GFP_KERNEL); 1953 if (!atdma) 1954 return -ENOMEM; 1955 1956 atdma->regs = devm_platform_ioremap_resource(pdev, 0); 1957 if (IS_ERR(atdma->regs)) 1958 return PTR_ERR(atdma->regs); 1959 1960 irq = platform_get_irq(pdev, 0); 1961 if (irq < 0) 1962 return irq; 1963 1964 /* discover transaction capabilities */ 1965 atdma->dma_device.cap_mask = plat_dat->cap_mask; 1966 atdma->all_chan_mask = (1 << plat_dat->nr_channels) - 1; 1967 1968 atdma->clk = devm_clk_get(&pdev->dev, "dma_clk"); 1969 if (IS_ERR(atdma->clk)) 1970 return PTR_ERR(atdma->clk); 1971 1972 err = clk_prepare_enable(atdma->clk); 1973 if (err) 1974 return err; 1975 1976 /* force dma off, just in case */ 1977 at_dma_off(atdma); 1978 1979 err = request_irq(irq, at_dma_interrupt, 0, "at_hdmac", atdma); 1980 if (err) 1981 goto err_irq; 1982 1983 platform_set_drvdata(pdev, atdma); 1984 1985 /* create a pool of consistent memory blocks for hardware descriptors */ 1986 atdma->lli_pool = dma_pool_create("at_hdmac_lli_pool", 1987 &pdev->dev, sizeof(struct at_lli), 1988 4 /* word alignment */, 0); 1989 if (!atdma->lli_pool) { 1990 dev_err(&pdev->dev, "Unable to allocate DMA LLI descriptor pool\n"); 1991 err = -ENOMEM; 1992 goto err_desc_pool_create; 1993 } 1994 1995 /* create a pool of consistent memory blocks for memset blocks */ 1996 atdma->memset_pool = dma_pool_create("at_hdmac_memset_pool", 1997 &pdev->dev, sizeof(int), 4, 0); 1998 if (!atdma->memset_pool) { 1999 dev_err(&pdev->dev, "No memory for memset dma pool\n"); 2000 err = -ENOMEM; 2001 goto err_memset_pool_create; 2002 } 2003 2004 /* clear any pending interrupt */ 2005 while (dma_readl(atdma, EBCISR)) 2006 cpu_relax(); 2007 2008 /* initialize channels related values */ 2009 INIT_LIST_HEAD(&atdma->dma_device.channels); 2010 for (i = 0; i < plat_dat->nr_channels; i++) { 2011 struct at_dma_chan *atchan = &atdma->chan[i]; 2012 2013 atchan->mem_if = AT_DMA_MEM_IF; 2014 atchan->per_if = AT_DMA_PER_IF; 2015 2016 atchan->ch_regs = atdma->regs + ch_regs(i); 2017 atchan->mask = 1 << i; 2018 2019 atchan->atdma = atdma; 2020 atchan->vc.desc_free = atdma_desc_free; 2021 vchan_init(&atchan->vc, &atdma->dma_device); 2022 atc_enable_chan_irq(atdma, i); 2023 } 2024 2025 /* set base routines */ 2026 atdma->dma_device.device_alloc_chan_resources = atc_alloc_chan_resources; 2027 atdma->dma_device.device_free_chan_resources = atc_free_chan_resources; 2028 atdma->dma_device.device_tx_status = atc_tx_status; 2029 atdma->dma_device.device_issue_pending = atc_issue_pending; 2030 atdma->dma_device.dev = &pdev->dev; 2031 2032 /* set prep routines based on capability */ 2033 if (dma_has_cap(DMA_INTERLEAVE, atdma->dma_device.cap_mask)) 2034 atdma->dma_device.device_prep_interleaved_dma = atc_prep_dma_interleaved; 2035 2036 if (dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask)) 2037 atdma->dma_device.device_prep_dma_memcpy = atc_prep_dma_memcpy; 2038 2039 if (dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask)) { 2040 atdma->dma_device.device_prep_dma_memset = atc_prep_dma_memset; 2041 atdma->dma_device.device_prep_dma_memset_sg = atc_prep_dma_memset_sg; 2042 atdma->dma_device.fill_align = DMAENGINE_ALIGN_4_BYTES; 2043 } 2044 2045 if (dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask)) { 2046 atdma->dma_device.device_prep_slave_sg = atc_prep_slave_sg; 2047 /* controller can do slave DMA: can trigger cyclic transfers */ 2048 dma_cap_set(DMA_CYCLIC, atdma->dma_device.cap_mask); 2049 atdma->dma_device.device_prep_dma_cyclic = atc_prep_dma_cyclic; 2050 atdma->dma_device.device_config = atc_config; 2051 atdma->dma_device.device_pause = atc_pause; 2052 atdma->dma_device.device_resume = atc_resume; 2053 atdma->dma_device.device_terminate_all = atc_terminate_all; 2054 atdma->dma_device.src_addr_widths = ATC_DMA_BUSWIDTHS; 2055 atdma->dma_device.dst_addr_widths = ATC_DMA_BUSWIDTHS; 2056 atdma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); 2057 atdma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; 2058 } 2059 2060 dma_writel(atdma, EN, AT_DMA_ENABLE); 2061 2062 dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n", 2063 dma_has_cap(DMA_MEMCPY, atdma->dma_device.cap_mask) ? "cpy " : "", 2064 dma_has_cap(DMA_MEMSET, atdma->dma_device.cap_mask) ? "set " : "", 2065 dma_has_cap(DMA_SLAVE, atdma->dma_device.cap_mask) ? "slave " : "", 2066 plat_dat->nr_channels); 2067 2068 err = dma_async_device_register(&atdma->dma_device); 2069 if (err) { 2070 dev_err(&pdev->dev, "Unable to register: %d.\n", err); 2071 goto err_dma_async_device_register; 2072 } 2073 2074 /* 2075 * Do not return an error if the dmac node is not present in order to 2076 * not break the existing way of requesting channel with 2077 * dma_request_channel(). 2078 */ 2079 if (pdev->dev.of_node) { 2080 err = of_dma_controller_register(pdev->dev.of_node, 2081 at_dma_xlate, atdma); 2082 if (err) { 2083 dev_err(&pdev->dev, "could not register of_dma_controller\n"); 2084 goto err_of_dma_controller_register; 2085 } 2086 } 2087 2088 return 0; 2089 2090 err_of_dma_controller_register: 2091 dma_async_device_unregister(&atdma->dma_device); 2092 err_dma_async_device_register: 2093 dma_pool_destroy(atdma->memset_pool); 2094 err_memset_pool_create: 2095 dma_pool_destroy(atdma->lli_pool); 2096 err_desc_pool_create: 2097 free_irq(platform_get_irq(pdev, 0), atdma); 2098 err_irq: 2099 clk_disable_unprepare(atdma->clk); 2100 return err; 2101 } 2102 2103 static void at_dma_remove(struct platform_device *pdev) 2104 { 2105 struct at_dma *atdma = platform_get_drvdata(pdev); 2106 struct dma_chan *chan, *_chan; 2107 2108 at_dma_off(atdma); 2109 if (pdev->dev.of_node) 2110 of_dma_controller_free(pdev->dev.of_node); 2111 dma_async_device_unregister(&atdma->dma_device); 2112 2113 dma_pool_destroy(atdma->memset_pool); 2114 dma_pool_destroy(atdma->lli_pool); 2115 free_irq(platform_get_irq(pdev, 0), atdma); 2116 2117 list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, 2118 device_node) { 2119 /* Disable interrupts */ 2120 atc_disable_chan_irq(atdma, chan->chan_id); 2121 list_del(&chan->device_node); 2122 } 2123 2124 clk_disable_unprepare(atdma->clk); 2125 } 2126 2127 static void at_dma_shutdown(struct platform_device *pdev) 2128 { 2129 struct at_dma *atdma = platform_get_drvdata(pdev); 2130 2131 at_dma_off(platform_get_drvdata(pdev)); 2132 clk_disable_unprepare(atdma->clk); 2133 } 2134 2135 static int at_dma_prepare(struct device *dev) 2136 { 2137 struct at_dma *atdma = dev_get_drvdata(dev); 2138 struct dma_chan *chan, *_chan; 2139 2140 list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, 2141 device_node) { 2142 struct at_dma_chan *atchan = to_at_dma_chan(chan); 2143 /* wait for transaction completion (except in cyclic case) */ 2144 if (atc_chan_is_enabled(atchan) && !atc_chan_is_cyclic(atchan)) 2145 return -EAGAIN; 2146 } 2147 return 0; 2148 } 2149 2150 static void atc_suspend_cyclic(struct at_dma_chan *atchan) 2151 { 2152 struct dma_chan *chan = &atchan->vc.chan; 2153 2154 /* Channel should be paused by user 2155 * do it anyway even if it is not done already */ 2156 if (!atc_chan_is_paused(atchan)) { 2157 dev_warn(chan2dev(chan), 2158 "cyclic channel not paused, should be done by channel user\n"); 2159 atc_pause(chan); 2160 } 2161 2162 /* now preserve additional data for cyclic operations */ 2163 /* next descriptor address in the cyclic list */ 2164 atchan->save_dscr = channel_readl(atchan, DSCR); 2165 2166 vdbg_dump_regs(atchan); 2167 } 2168 2169 static int at_dma_suspend_noirq(struct device *dev) 2170 { 2171 struct at_dma *atdma = dev_get_drvdata(dev); 2172 struct dma_chan *chan, *_chan; 2173 2174 /* preserve data */ 2175 list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, 2176 device_node) { 2177 struct at_dma_chan *atchan = to_at_dma_chan(chan); 2178 2179 if (atc_chan_is_cyclic(atchan)) 2180 atc_suspend_cyclic(atchan); 2181 atchan->save_cfg = channel_readl(atchan, CFG); 2182 } 2183 atdma->save_imr = dma_readl(atdma, EBCIMR); 2184 2185 /* disable DMA controller */ 2186 at_dma_off(atdma); 2187 clk_disable_unprepare(atdma->clk); 2188 return 0; 2189 } 2190 2191 static void atc_resume_cyclic(struct at_dma_chan *atchan) 2192 { 2193 struct at_dma *atdma = to_at_dma(atchan->vc.chan.device); 2194 2195 /* restore channel status for cyclic descriptors list: 2196 * next descriptor in the cyclic list at the time of suspend */ 2197 channel_writel(atchan, SADDR, 0); 2198 channel_writel(atchan, DADDR, 0); 2199 channel_writel(atchan, CTRLA, 0); 2200 channel_writel(atchan, CTRLB, 0); 2201 channel_writel(atchan, DSCR, atchan->save_dscr); 2202 dma_writel(atdma, CHER, atchan->mask); 2203 2204 /* channel pause status should be removed by channel user 2205 * We cannot take the initiative to do it here */ 2206 2207 vdbg_dump_regs(atchan); 2208 } 2209 2210 static int at_dma_resume_noirq(struct device *dev) 2211 { 2212 struct at_dma *atdma = dev_get_drvdata(dev); 2213 struct dma_chan *chan, *_chan; 2214 2215 /* bring back DMA controller */ 2216 clk_prepare_enable(atdma->clk); 2217 dma_writel(atdma, EN, AT_DMA_ENABLE); 2218 2219 /* clear any pending interrupt */ 2220 while (dma_readl(atdma, EBCISR)) 2221 cpu_relax(); 2222 2223 /* restore saved data */ 2224 dma_writel(atdma, EBCIER, atdma->save_imr); 2225 list_for_each_entry_safe(chan, _chan, &atdma->dma_device.channels, 2226 device_node) { 2227 struct at_dma_chan *atchan = to_at_dma_chan(chan); 2228 2229 channel_writel(atchan, CFG, atchan->save_cfg); 2230 if (atc_chan_is_cyclic(atchan)) 2231 atc_resume_cyclic(atchan); 2232 } 2233 return 0; 2234 } 2235 2236 static const struct dev_pm_ops __maybe_unused at_dma_dev_pm_ops = { 2237 .prepare = at_dma_prepare, 2238 .suspend_noirq = at_dma_suspend_noirq, 2239 .resume_noirq = at_dma_resume_noirq, 2240 }; 2241 2242 static struct platform_driver at_dma_driver = { 2243 .remove_new = at_dma_remove, 2244 .shutdown = at_dma_shutdown, 2245 .id_table = atdma_devtypes, 2246 .driver = { 2247 .name = "at_hdmac", 2248 .pm = pm_ptr(&at_dma_dev_pm_ops), 2249 .of_match_table = of_match_ptr(atmel_dma_dt_ids), 2250 }, 2251 }; 2252 2253 static int __init at_dma_init(void) 2254 { 2255 return platform_driver_probe(&at_dma_driver, at_dma_probe); 2256 } 2257 subsys_initcall(at_dma_init); 2258 2259 static void __exit at_dma_exit(void) 2260 { 2261 platform_driver_unregister(&at_dma_driver); 2262 } 2263 module_exit(at_dma_exit); 2264 2265 MODULE_DESCRIPTION("Atmel AHB DMA Controller driver"); 2266 MODULE_AUTHOR("Nicolas Ferre <nicolas.ferre@atmel.com>"); 2267 MODULE_AUTHOR("Tudor Ambarus <tudor.ambarus@microchip.com>"); 2268 MODULE_LICENSE("GPL"); 2269 MODULE_ALIAS("platform:at_hdmac"); 2270