1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // Copyright 2011 Freescale Semiconductor, Inc. All Rights Reserved. 4 // 5 // Refer to drivers/dma/imx-sdma.c 6 7 #include <linux/init.h> 8 #include <linux/types.h> 9 #include <linux/mm.h> 10 #include <linux/interrupt.h> 11 #include <linux/clk.h> 12 #include <linux/wait.h> 13 #include <linux/sched.h> 14 #include <linux/semaphore.h> 15 #include <linux/device.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/slab.h> 18 #include <linux/platform_device.h> 19 #include <linux/dmaengine.h> 20 #include <linux/delay.h> 21 #include <linux/module.h> 22 #include <linux/stmp_device.h> 23 #include <linux/of.h> 24 #include <linux/of_device.h> 25 #include <linux/of_dma.h> 26 #include <linux/list.h> 27 #include <linux/dma/mxs-dma.h> 28 29 #include <asm/irq.h> 30 31 #include "dmaengine.h" 32 33 /* 34 * NOTE: The term "PIO" throughout the mxs-dma implementation means 35 * PIO mode of mxs apbh-dma and apbx-dma. With this working mode, 36 * dma can program the controller registers of peripheral devices. 37 */ 38 39 #define dma_is_apbh(mxs_dma) ((mxs_dma)->type == MXS_DMA_APBH) 40 #define apbh_is_old(mxs_dma) ((mxs_dma)->dev_id == IMX23_DMA) 41 42 #define HW_APBHX_CTRL0 0x000 43 #define BM_APBH_CTRL0_APB_BURST8_EN (1 << 29) 44 #define BM_APBH_CTRL0_APB_BURST_EN (1 << 28) 45 #define BP_APBH_CTRL0_RESET_CHANNEL 16 46 #define HW_APBHX_CTRL1 0x010 47 #define HW_APBHX_CTRL2 0x020 48 #define HW_APBHX_CHANNEL_CTRL 0x030 49 #define BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL 16 50 /* 51 * The offset of NXTCMDAR register is different per both dma type and version, 52 * while stride for each channel is all the same 0x70. 53 */ 54 #define HW_APBHX_CHn_NXTCMDAR(d, n) \ 55 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x050 : 0x110) + (n) * 0x70) 56 #define HW_APBHX_CHn_SEMA(d, n) \ 57 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x080 : 0x140) + (n) * 0x70) 58 #define HW_APBHX_CHn_BAR(d, n) \ 59 (((dma_is_apbh(d) && apbh_is_old(d)) ? 0x070 : 0x130) + (n) * 0x70) 60 #define HW_APBX_CHn_DEBUG1(d, n) (0x150 + (n) * 0x70) 61 62 /* 63 * ccw bits definitions 64 * 65 * COMMAND: 0..1 (2) 66 * CHAIN: 2 (1) 67 * IRQ: 3 (1) 68 * NAND_LOCK: 4 (1) - not implemented 69 * NAND_WAIT4READY: 5 (1) - not implemented 70 * DEC_SEM: 6 (1) 71 * WAIT4END: 7 (1) 72 * HALT_ON_TERMINATE: 8 (1) 73 * TERMINATE_FLUSH: 9 (1) 74 * RESERVED: 10..11 (2) 75 * PIO_NUM: 12..15 (4) 76 */ 77 #define BP_CCW_COMMAND 0 78 #define BM_CCW_COMMAND (3 << 0) 79 #define CCW_CHAIN (1 << 2) 80 #define CCW_IRQ (1 << 3) 81 #define CCW_WAIT4RDY (1 << 5) 82 #define CCW_DEC_SEM (1 << 6) 83 #define CCW_WAIT4END (1 << 7) 84 #define CCW_HALT_ON_TERM (1 << 8) 85 #define CCW_TERM_FLUSH (1 << 9) 86 #define BP_CCW_PIO_NUM 12 87 #define BM_CCW_PIO_NUM (0xf << 12) 88 89 #define BF_CCW(value, field) (((value) << BP_CCW_##field) & BM_CCW_##field) 90 91 #define MXS_DMA_CMD_NO_XFER 0 92 #define MXS_DMA_CMD_WRITE 1 93 #define MXS_DMA_CMD_READ 2 94 #define MXS_DMA_CMD_DMA_SENSE 3 /* not implemented */ 95 96 struct mxs_dma_ccw { 97 u32 next; 98 u16 bits; 99 u16 xfer_bytes; 100 #define MAX_XFER_BYTES 0xff00 101 u32 bufaddr; 102 #define MXS_PIO_WORDS 16 103 u32 pio_words[MXS_PIO_WORDS]; 104 }; 105 106 #define CCW_BLOCK_SIZE (4 * PAGE_SIZE) 107 #define NUM_CCW (int)(CCW_BLOCK_SIZE / sizeof(struct mxs_dma_ccw)) 108 109 struct mxs_dma_chan { 110 struct mxs_dma_engine *mxs_dma; 111 struct dma_chan chan; 112 struct dma_async_tx_descriptor desc; 113 struct tasklet_struct tasklet; 114 unsigned int chan_irq; 115 struct mxs_dma_ccw *ccw; 116 dma_addr_t ccw_phys; 117 int desc_count; 118 enum dma_status status; 119 unsigned int flags; 120 bool reset; 121 #define MXS_DMA_SG_LOOP (1 << 0) 122 #define MXS_DMA_USE_SEMAPHORE (1 << 1) 123 }; 124 125 #define MXS_DMA_CHANNELS 16 126 #define MXS_DMA_CHANNELS_MASK 0xffff 127 128 enum mxs_dma_devtype { 129 MXS_DMA_APBH, 130 MXS_DMA_APBX, 131 }; 132 133 enum mxs_dma_id { 134 IMX23_DMA, 135 IMX28_DMA, 136 }; 137 138 struct mxs_dma_engine { 139 enum mxs_dma_id dev_id; 140 enum mxs_dma_devtype type; 141 void __iomem *base; 142 struct clk *clk; 143 struct dma_device dma_device; 144 struct mxs_dma_chan mxs_chans[MXS_DMA_CHANNELS]; 145 struct platform_device *pdev; 146 unsigned int nr_channels; 147 }; 148 149 struct mxs_dma_type { 150 enum mxs_dma_id id; 151 enum mxs_dma_devtype type; 152 }; 153 154 static struct mxs_dma_type mxs_dma_types[] = { 155 { 156 .id = IMX23_DMA, 157 .type = MXS_DMA_APBH, 158 }, { 159 .id = IMX23_DMA, 160 .type = MXS_DMA_APBX, 161 }, { 162 .id = IMX28_DMA, 163 .type = MXS_DMA_APBH, 164 }, { 165 .id = IMX28_DMA, 166 .type = MXS_DMA_APBX, 167 } 168 }; 169 170 static const struct of_device_id mxs_dma_dt_ids[] = { 171 { .compatible = "fsl,imx23-dma-apbh", .data = &mxs_dma_types[0], }, 172 { .compatible = "fsl,imx23-dma-apbx", .data = &mxs_dma_types[1], }, 173 { .compatible = "fsl,imx28-dma-apbh", .data = &mxs_dma_types[2], }, 174 { .compatible = "fsl,imx28-dma-apbx", .data = &mxs_dma_types[3], }, 175 { /* sentinel */ } 176 }; 177 MODULE_DEVICE_TABLE(of, mxs_dma_dt_ids); 178 179 static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan) 180 { 181 return container_of(chan, struct mxs_dma_chan, chan); 182 } 183 184 static void mxs_dma_reset_chan(struct dma_chan *chan) 185 { 186 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 187 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 188 int chan_id = mxs_chan->chan.chan_id; 189 190 /* 191 * mxs dma channel resets can cause a channel stall. To recover from a 192 * channel stall, we have to reset the whole DMA engine. To avoid this, 193 * we use cyclic DMA with semaphores, that are enhanced in 194 * mxs_dma_int_handler. To reset the channel, we can simply stop writing 195 * into the semaphore counter. 196 */ 197 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE && 198 mxs_chan->flags & MXS_DMA_SG_LOOP) { 199 mxs_chan->reset = true; 200 } else if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) { 201 writel(1 << (chan_id + BP_APBH_CTRL0_RESET_CHANNEL), 202 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); 203 } else { 204 unsigned long elapsed = 0; 205 const unsigned long max_wait = 50000; /* 50ms */ 206 void __iomem *reg_dbg1 = mxs_dma->base + 207 HW_APBX_CHn_DEBUG1(mxs_dma, chan_id); 208 209 /* 210 * On i.MX28 APBX, the DMA channel can stop working if we reset 211 * the channel while it is in READ_FLUSH (0x08) state. 212 * We wait here until we leave the state. Then we trigger the 213 * reset. Waiting a maximum of 50ms, the kernel shouldn't crash 214 * because of this. 215 */ 216 while ((readl(reg_dbg1) & 0xf) == 0x8 && elapsed < max_wait) { 217 udelay(100); 218 elapsed += 100; 219 } 220 221 if (elapsed >= max_wait) 222 dev_err(&mxs_chan->mxs_dma->pdev->dev, 223 "Failed waiting for the DMA channel %d to leave state READ_FLUSH, trying to reset channel in READ_FLUSH state now\n", 224 chan_id); 225 226 writel(1 << (chan_id + BP_APBHX_CHANNEL_CTRL_RESET_CHANNEL), 227 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET); 228 } 229 230 mxs_chan->status = DMA_COMPLETE; 231 } 232 233 static void mxs_dma_enable_chan(struct dma_chan *chan) 234 { 235 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 236 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 237 int chan_id = mxs_chan->chan.chan_id; 238 239 /* set cmd_addr up */ 240 writel(mxs_chan->ccw_phys, 241 mxs_dma->base + HW_APBHX_CHn_NXTCMDAR(mxs_dma, chan_id)); 242 243 /* write 1 to SEMA to kick off the channel */ 244 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE && 245 mxs_chan->flags & MXS_DMA_SG_LOOP) { 246 /* A cyclic DMA consists of at least 2 segments, so initialize 247 * the semaphore with 2 so we have enough time to add 1 to the 248 * semaphore if we need to */ 249 writel(2, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id)); 250 } else { 251 writel(1, mxs_dma->base + HW_APBHX_CHn_SEMA(mxs_dma, chan_id)); 252 } 253 mxs_chan->reset = false; 254 } 255 256 static void mxs_dma_disable_chan(struct dma_chan *chan) 257 { 258 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 259 260 mxs_chan->status = DMA_COMPLETE; 261 } 262 263 static int mxs_dma_pause_chan(struct dma_chan *chan) 264 { 265 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 266 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 267 int chan_id = mxs_chan->chan.chan_id; 268 269 /* freeze the channel */ 270 if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) 271 writel(1 << chan_id, 272 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); 273 else 274 writel(1 << chan_id, 275 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_SET); 276 277 mxs_chan->status = DMA_PAUSED; 278 return 0; 279 } 280 281 static int mxs_dma_resume_chan(struct dma_chan *chan) 282 { 283 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 284 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 285 int chan_id = mxs_chan->chan.chan_id; 286 287 /* unfreeze the channel */ 288 if (dma_is_apbh(mxs_dma) && apbh_is_old(mxs_dma)) 289 writel(1 << chan_id, 290 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_CLR); 291 else 292 writel(1 << chan_id, 293 mxs_dma->base + HW_APBHX_CHANNEL_CTRL + STMP_OFFSET_REG_CLR); 294 295 mxs_chan->status = DMA_IN_PROGRESS; 296 return 0; 297 } 298 299 static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx) 300 { 301 return dma_cookie_assign(tx); 302 } 303 304 static void mxs_dma_tasklet(struct tasklet_struct *t) 305 { 306 struct mxs_dma_chan *mxs_chan = from_tasklet(mxs_chan, t, tasklet); 307 308 dmaengine_desc_get_callback_invoke(&mxs_chan->desc, NULL); 309 } 310 311 static int mxs_dma_irq_to_chan(struct mxs_dma_engine *mxs_dma, int irq) 312 { 313 int i; 314 315 for (i = 0; i != mxs_dma->nr_channels; ++i) 316 if (mxs_dma->mxs_chans[i].chan_irq == irq) 317 return i; 318 319 return -EINVAL; 320 } 321 322 static irqreturn_t mxs_dma_int_handler(int irq, void *dev_id) 323 { 324 struct mxs_dma_engine *mxs_dma = dev_id; 325 struct mxs_dma_chan *mxs_chan; 326 u32 completed; 327 u32 err; 328 int chan = mxs_dma_irq_to_chan(mxs_dma, irq); 329 330 if (chan < 0) 331 return IRQ_NONE; 332 333 /* completion status */ 334 completed = readl(mxs_dma->base + HW_APBHX_CTRL1); 335 completed = (completed >> chan) & 0x1; 336 337 /* Clear interrupt */ 338 writel((1 << chan), 339 mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_CLR); 340 341 /* error status */ 342 err = readl(mxs_dma->base + HW_APBHX_CTRL2); 343 err &= (1 << (MXS_DMA_CHANNELS + chan)) | (1 << chan); 344 345 /* 346 * error status bit is in the upper 16 bits, error irq bit in the lower 347 * 16 bits. We transform it into a simpler error code: 348 * err: 0x00 = no error, 0x01 = TERMINATION, 0x02 = BUS_ERROR 349 */ 350 err = (err >> (MXS_DMA_CHANNELS + chan)) + (err >> chan); 351 352 /* Clear error irq */ 353 writel((1 << chan), 354 mxs_dma->base + HW_APBHX_CTRL2 + STMP_OFFSET_REG_CLR); 355 356 /* 357 * When both completion and error of termination bits set at the 358 * same time, we do not take it as an error. IOW, it only becomes 359 * an error we need to handle here in case of either it's a bus 360 * error or a termination error with no completion. 0x01 is termination 361 * error, so we can subtract err & completed to get the real error case. 362 */ 363 err -= err & completed; 364 365 mxs_chan = &mxs_dma->mxs_chans[chan]; 366 367 if (err) { 368 dev_dbg(mxs_dma->dma_device.dev, 369 "%s: error in channel %d\n", __func__, 370 chan); 371 mxs_chan->status = DMA_ERROR; 372 mxs_dma_reset_chan(&mxs_chan->chan); 373 } else if (mxs_chan->status != DMA_COMPLETE) { 374 if (mxs_chan->flags & MXS_DMA_SG_LOOP) { 375 mxs_chan->status = DMA_IN_PROGRESS; 376 if (mxs_chan->flags & MXS_DMA_USE_SEMAPHORE) 377 writel(1, mxs_dma->base + 378 HW_APBHX_CHn_SEMA(mxs_dma, chan)); 379 } else { 380 mxs_chan->status = DMA_COMPLETE; 381 } 382 } 383 384 if (mxs_chan->status == DMA_COMPLETE) { 385 if (mxs_chan->reset) 386 return IRQ_HANDLED; 387 dma_cookie_complete(&mxs_chan->desc); 388 } 389 390 /* schedule tasklet on this channel */ 391 tasklet_schedule(&mxs_chan->tasklet); 392 393 return IRQ_HANDLED; 394 } 395 396 static int mxs_dma_alloc_chan_resources(struct dma_chan *chan) 397 { 398 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 399 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 400 int ret; 401 402 mxs_chan->ccw = dma_alloc_coherent(mxs_dma->dma_device.dev, 403 CCW_BLOCK_SIZE, 404 &mxs_chan->ccw_phys, GFP_KERNEL); 405 if (!mxs_chan->ccw) { 406 ret = -ENOMEM; 407 goto err_alloc; 408 } 409 410 ret = request_irq(mxs_chan->chan_irq, mxs_dma_int_handler, 411 0, "mxs-dma", mxs_dma); 412 if (ret) 413 goto err_irq; 414 415 ret = clk_prepare_enable(mxs_dma->clk); 416 if (ret) 417 goto err_clk; 418 419 mxs_dma_reset_chan(chan); 420 421 dma_async_tx_descriptor_init(&mxs_chan->desc, chan); 422 mxs_chan->desc.tx_submit = mxs_dma_tx_submit; 423 424 /* the descriptor is ready */ 425 async_tx_ack(&mxs_chan->desc); 426 427 return 0; 428 429 err_clk: 430 free_irq(mxs_chan->chan_irq, mxs_dma); 431 err_irq: 432 dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE, 433 mxs_chan->ccw, mxs_chan->ccw_phys); 434 err_alloc: 435 return ret; 436 } 437 438 static void mxs_dma_free_chan_resources(struct dma_chan *chan) 439 { 440 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 441 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 442 443 mxs_dma_disable_chan(chan); 444 445 free_irq(mxs_chan->chan_irq, mxs_dma); 446 447 dma_free_coherent(mxs_dma->dma_device.dev, CCW_BLOCK_SIZE, 448 mxs_chan->ccw, mxs_chan->ccw_phys); 449 450 clk_disable_unprepare(mxs_dma->clk); 451 } 452 453 /* 454 * How to use the flags for ->device_prep_slave_sg() : 455 * [1] If there is only one DMA command in the DMA chain, the code should be: 456 * ...... 457 * ->device_prep_slave_sg(DMA_CTRL_ACK); 458 * ...... 459 * [2] If there are two DMA commands in the DMA chain, the code should be 460 * ...... 461 * ->device_prep_slave_sg(0); 462 * ...... 463 * ->device_prep_slave_sg(DMA_CTRL_ACK); 464 * ...... 465 * [3] If there are more than two DMA commands in the DMA chain, the code 466 * should be: 467 * ...... 468 * ->device_prep_slave_sg(0); // First 469 * ...... 470 * ->device_prep_slave_sg(DMA_CTRL_ACK]); 471 * ...... 472 * ->device_prep_slave_sg(DMA_CTRL_ACK); // Last 473 * ...... 474 */ 475 static struct dma_async_tx_descriptor *mxs_dma_prep_slave_sg( 476 struct dma_chan *chan, struct scatterlist *sgl, 477 unsigned int sg_len, enum dma_transfer_direction direction, 478 unsigned long flags, void *context) 479 { 480 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 481 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 482 struct mxs_dma_ccw *ccw; 483 struct scatterlist *sg; 484 u32 i, j; 485 u32 *pio; 486 int idx = 0; 487 488 if (mxs_chan->status == DMA_IN_PROGRESS) 489 idx = mxs_chan->desc_count; 490 491 if (sg_len + idx > NUM_CCW) { 492 dev_err(mxs_dma->dma_device.dev, 493 "maximum number of sg exceeded: %d > %d\n", 494 sg_len, NUM_CCW); 495 goto err_out; 496 } 497 498 mxs_chan->status = DMA_IN_PROGRESS; 499 mxs_chan->flags = 0; 500 501 /* 502 * If the sg is prepared with append flag set, the sg 503 * will be appended to the last prepared sg. 504 */ 505 if (idx) { 506 BUG_ON(idx < 1); 507 ccw = &mxs_chan->ccw[idx - 1]; 508 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx; 509 ccw->bits |= CCW_CHAIN; 510 ccw->bits &= ~CCW_IRQ; 511 ccw->bits &= ~CCW_DEC_SEM; 512 } else { 513 idx = 0; 514 } 515 516 if (direction == DMA_TRANS_NONE) { 517 ccw = &mxs_chan->ccw[idx++]; 518 pio = (u32 *) sgl; 519 520 for (j = 0; j < sg_len;) 521 ccw->pio_words[j++] = *pio++; 522 523 ccw->bits = 0; 524 ccw->bits |= CCW_IRQ; 525 ccw->bits |= CCW_DEC_SEM; 526 if (flags & MXS_DMA_CTRL_WAIT4END) 527 ccw->bits |= CCW_WAIT4END; 528 ccw->bits |= CCW_HALT_ON_TERM; 529 ccw->bits |= CCW_TERM_FLUSH; 530 ccw->bits |= BF_CCW(sg_len, PIO_NUM); 531 ccw->bits |= BF_CCW(MXS_DMA_CMD_NO_XFER, COMMAND); 532 if (flags & MXS_DMA_CTRL_WAIT4RDY) 533 ccw->bits |= CCW_WAIT4RDY; 534 } else { 535 for_each_sg(sgl, sg, sg_len, i) { 536 if (sg_dma_len(sg) > MAX_XFER_BYTES) { 537 dev_err(mxs_dma->dma_device.dev, "maximum bytes for sg entry exceeded: %d > %d\n", 538 sg_dma_len(sg), MAX_XFER_BYTES); 539 goto err_out; 540 } 541 542 ccw = &mxs_chan->ccw[idx++]; 543 544 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * idx; 545 ccw->bufaddr = sg->dma_address; 546 ccw->xfer_bytes = sg_dma_len(sg); 547 548 ccw->bits = 0; 549 ccw->bits |= CCW_CHAIN; 550 ccw->bits |= CCW_HALT_ON_TERM; 551 ccw->bits |= CCW_TERM_FLUSH; 552 ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ? 553 MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, 554 COMMAND); 555 556 if (i + 1 == sg_len) { 557 ccw->bits &= ~CCW_CHAIN; 558 ccw->bits |= CCW_IRQ; 559 ccw->bits |= CCW_DEC_SEM; 560 if (flags & MXS_DMA_CTRL_WAIT4END) 561 ccw->bits |= CCW_WAIT4END; 562 } 563 } 564 } 565 mxs_chan->desc_count = idx; 566 567 return &mxs_chan->desc; 568 569 err_out: 570 mxs_chan->status = DMA_ERROR; 571 return NULL; 572 } 573 574 static struct dma_async_tx_descriptor *mxs_dma_prep_dma_cyclic( 575 struct dma_chan *chan, dma_addr_t dma_addr, size_t buf_len, 576 size_t period_len, enum dma_transfer_direction direction, 577 unsigned long flags) 578 { 579 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 580 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 581 u32 num_periods = buf_len / period_len; 582 u32 i = 0, buf = 0; 583 584 if (mxs_chan->status == DMA_IN_PROGRESS) 585 return NULL; 586 587 mxs_chan->status = DMA_IN_PROGRESS; 588 mxs_chan->flags |= MXS_DMA_SG_LOOP; 589 mxs_chan->flags |= MXS_DMA_USE_SEMAPHORE; 590 591 if (num_periods > NUM_CCW) { 592 dev_err(mxs_dma->dma_device.dev, 593 "maximum number of sg exceeded: %d > %d\n", 594 num_periods, NUM_CCW); 595 goto err_out; 596 } 597 598 if (period_len > MAX_XFER_BYTES) { 599 dev_err(mxs_dma->dma_device.dev, 600 "maximum period size exceeded: %zu > %d\n", 601 period_len, MAX_XFER_BYTES); 602 goto err_out; 603 } 604 605 while (buf < buf_len) { 606 struct mxs_dma_ccw *ccw = &mxs_chan->ccw[i]; 607 608 if (i + 1 == num_periods) 609 ccw->next = mxs_chan->ccw_phys; 610 else 611 ccw->next = mxs_chan->ccw_phys + sizeof(*ccw) * (i + 1); 612 613 ccw->bufaddr = dma_addr; 614 ccw->xfer_bytes = period_len; 615 616 ccw->bits = 0; 617 ccw->bits |= CCW_CHAIN; 618 ccw->bits |= CCW_IRQ; 619 ccw->bits |= CCW_HALT_ON_TERM; 620 ccw->bits |= CCW_TERM_FLUSH; 621 ccw->bits |= CCW_DEC_SEM; 622 ccw->bits |= BF_CCW(direction == DMA_DEV_TO_MEM ? 623 MXS_DMA_CMD_WRITE : MXS_DMA_CMD_READ, COMMAND); 624 625 dma_addr += period_len; 626 buf += period_len; 627 628 i++; 629 } 630 mxs_chan->desc_count = i; 631 632 return &mxs_chan->desc; 633 634 err_out: 635 mxs_chan->status = DMA_ERROR; 636 return NULL; 637 } 638 639 static int mxs_dma_terminate_all(struct dma_chan *chan) 640 { 641 mxs_dma_reset_chan(chan); 642 mxs_dma_disable_chan(chan); 643 644 return 0; 645 } 646 647 static enum dma_status mxs_dma_tx_status(struct dma_chan *chan, 648 dma_cookie_t cookie, struct dma_tx_state *txstate) 649 { 650 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 651 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 652 u32 residue = 0; 653 654 if (mxs_chan->status == DMA_IN_PROGRESS && 655 mxs_chan->flags & MXS_DMA_SG_LOOP) { 656 struct mxs_dma_ccw *last_ccw; 657 u32 bar; 658 659 last_ccw = &mxs_chan->ccw[mxs_chan->desc_count - 1]; 660 residue = last_ccw->xfer_bytes + last_ccw->bufaddr; 661 662 bar = readl(mxs_dma->base + 663 HW_APBHX_CHn_BAR(mxs_dma, chan->chan_id)); 664 residue -= bar; 665 } 666 667 dma_set_tx_state(txstate, chan->completed_cookie, chan->cookie, 668 residue); 669 670 return mxs_chan->status; 671 } 672 673 static int mxs_dma_init(struct mxs_dma_engine *mxs_dma) 674 { 675 int ret; 676 677 ret = clk_prepare_enable(mxs_dma->clk); 678 if (ret) 679 return ret; 680 681 ret = stmp_reset_block(mxs_dma->base); 682 if (ret) 683 goto err_out; 684 685 /* enable apbh burst */ 686 if (dma_is_apbh(mxs_dma)) { 687 writel(BM_APBH_CTRL0_APB_BURST_EN, 688 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); 689 writel(BM_APBH_CTRL0_APB_BURST8_EN, 690 mxs_dma->base + HW_APBHX_CTRL0 + STMP_OFFSET_REG_SET); 691 } 692 693 /* enable irq for all the channels */ 694 writel(MXS_DMA_CHANNELS_MASK << MXS_DMA_CHANNELS, 695 mxs_dma->base + HW_APBHX_CTRL1 + STMP_OFFSET_REG_SET); 696 697 err_out: 698 clk_disable_unprepare(mxs_dma->clk); 699 return ret; 700 } 701 702 struct mxs_dma_filter_param { 703 unsigned int chan_id; 704 }; 705 706 static bool mxs_dma_filter_fn(struct dma_chan *chan, void *fn_param) 707 { 708 struct mxs_dma_filter_param *param = fn_param; 709 struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan); 710 struct mxs_dma_engine *mxs_dma = mxs_chan->mxs_dma; 711 int chan_irq; 712 713 if (chan->chan_id != param->chan_id) 714 return false; 715 716 chan_irq = platform_get_irq(mxs_dma->pdev, param->chan_id); 717 if (chan_irq < 0) 718 return false; 719 720 mxs_chan->chan_irq = chan_irq; 721 722 return true; 723 } 724 725 static struct dma_chan *mxs_dma_xlate(struct of_phandle_args *dma_spec, 726 struct of_dma *ofdma) 727 { 728 struct mxs_dma_engine *mxs_dma = ofdma->of_dma_data; 729 dma_cap_mask_t mask = mxs_dma->dma_device.cap_mask; 730 struct mxs_dma_filter_param param; 731 732 if (dma_spec->args_count != 1) 733 return NULL; 734 735 param.chan_id = dma_spec->args[0]; 736 737 if (param.chan_id >= mxs_dma->nr_channels) 738 return NULL; 739 740 return __dma_request_channel(&mask, mxs_dma_filter_fn, ¶m, 741 ofdma->of_node); 742 } 743 744 static int mxs_dma_probe(struct platform_device *pdev) 745 { 746 struct device_node *np = pdev->dev.of_node; 747 const struct mxs_dma_type *dma_type; 748 struct mxs_dma_engine *mxs_dma; 749 int ret, i; 750 751 mxs_dma = devm_kzalloc(&pdev->dev, sizeof(*mxs_dma), GFP_KERNEL); 752 if (!mxs_dma) 753 return -ENOMEM; 754 755 ret = of_property_read_u32(np, "dma-channels", &mxs_dma->nr_channels); 756 if (ret) { 757 dev_err(&pdev->dev, "failed to read dma-channels\n"); 758 return ret; 759 } 760 761 dma_type = (struct mxs_dma_type *)of_device_get_match_data(&pdev->dev); 762 mxs_dma->type = dma_type->type; 763 mxs_dma->dev_id = dma_type->id; 764 765 mxs_dma->base = devm_platform_ioremap_resource(pdev, 0); 766 if (IS_ERR(mxs_dma->base)) 767 return PTR_ERR(mxs_dma->base); 768 769 mxs_dma->clk = devm_clk_get(&pdev->dev, NULL); 770 if (IS_ERR(mxs_dma->clk)) 771 return PTR_ERR(mxs_dma->clk); 772 773 dma_cap_set(DMA_SLAVE, mxs_dma->dma_device.cap_mask); 774 dma_cap_set(DMA_CYCLIC, mxs_dma->dma_device.cap_mask); 775 776 INIT_LIST_HEAD(&mxs_dma->dma_device.channels); 777 778 /* Initialize channel parameters */ 779 for (i = 0; i < MXS_DMA_CHANNELS; i++) { 780 struct mxs_dma_chan *mxs_chan = &mxs_dma->mxs_chans[i]; 781 782 mxs_chan->mxs_dma = mxs_dma; 783 mxs_chan->chan.device = &mxs_dma->dma_device; 784 dma_cookie_init(&mxs_chan->chan); 785 786 tasklet_setup(&mxs_chan->tasklet, mxs_dma_tasklet); 787 788 789 /* Add the channel to mxs_chan list */ 790 list_add_tail(&mxs_chan->chan.device_node, 791 &mxs_dma->dma_device.channels); 792 } 793 794 ret = mxs_dma_init(mxs_dma); 795 if (ret) 796 return ret; 797 798 mxs_dma->pdev = pdev; 799 mxs_dma->dma_device.dev = &pdev->dev; 800 801 /* mxs_dma gets 65535 bytes maximum sg size */ 802 dma_set_max_seg_size(mxs_dma->dma_device.dev, MAX_XFER_BYTES); 803 804 mxs_dma->dma_device.device_alloc_chan_resources = mxs_dma_alloc_chan_resources; 805 mxs_dma->dma_device.device_free_chan_resources = mxs_dma_free_chan_resources; 806 mxs_dma->dma_device.device_tx_status = mxs_dma_tx_status; 807 mxs_dma->dma_device.device_prep_slave_sg = mxs_dma_prep_slave_sg; 808 mxs_dma->dma_device.device_prep_dma_cyclic = mxs_dma_prep_dma_cyclic; 809 mxs_dma->dma_device.device_pause = mxs_dma_pause_chan; 810 mxs_dma->dma_device.device_resume = mxs_dma_resume_chan; 811 mxs_dma->dma_device.device_terminate_all = mxs_dma_terminate_all; 812 mxs_dma->dma_device.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 813 mxs_dma->dma_device.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); 814 mxs_dma->dma_device.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); 815 mxs_dma->dma_device.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; 816 mxs_dma->dma_device.device_issue_pending = mxs_dma_enable_chan; 817 818 ret = dmaenginem_async_device_register(&mxs_dma->dma_device); 819 if (ret) { 820 dev_err(mxs_dma->dma_device.dev, "unable to register\n"); 821 return ret; 822 } 823 824 ret = of_dma_controller_register(np, mxs_dma_xlate, mxs_dma); 825 if (ret) { 826 dev_err(mxs_dma->dma_device.dev, 827 "failed to register controller\n"); 828 } 829 830 dev_info(mxs_dma->dma_device.dev, "initialized\n"); 831 832 return 0; 833 } 834 835 static struct platform_driver mxs_dma_driver = { 836 .driver = { 837 .name = "mxs-dma", 838 .of_match_table = mxs_dma_dt_ids, 839 }, 840 .probe = mxs_dma_probe, 841 }; 842 843 builtin_platform_driver(mxs_dma_driver); 844