1 // SPDX-License-Identifier: GPL-2.0+ 2 // 3 // Freescale i.MX7ULP LPSPI driver 4 // 5 // Copyright 2016 Freescale Semiconductor, Inc. 6 // Copyright 2018 NXP Semiconductors 7 8 #include <linux/clk.h> 9 #include <linux/completion.h> 10 #include <linux/delay.h> 11 #include <linux/dmaengine.h> 12 #include <linux/dma-mapping.h> 13 #include <linux/err.h> 14 #include <linux/interrupt.h> 15 #include <linux/io.h> 16 #include <linux/irq.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/of_device.h> 21 #include <linux/pinctrl/consumer.h> 22 #include <linux/platform_device.h> 23 #include <linux/dma/imx-dma.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/slab.h> 26 #include <linux/spi/spi.h> 27 #include <linux/spi/spi_bitbang.h> 28 #include <linux/types.h> 29 30 #define DRIVER_NAME "fsl_lpspi" 31 32 #define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */ 33 34 /* The maximum bytes that edma can transfer once.*/ 35 #define FSL_LPSPI_MAX_EDMA_BYTES ((1 << 15) - 1) 36 37 /* i.MX7ULP LPSPI registers */ 38 #define IMX7ULP_VERID 0x0 39 #define IMX7ULP_PARAM 0x4 40 #define IMX7ULP_CR 0x10 41 #define IMX7ULP_SR 0x14 42 #define IMX7ULP_IER 0x18 43 #define IMX7ULP_DER 0x1c 44 #define IMX7ULP_CFGR0 0x20 45 #define IMX7ULP_CFGR1 0x24 46 #define IMX7ULP_DMR0 0x30 47 #define IMX7ULP_DMR1 0x34 48 #define IMX7ULP_CCR 0x40 49 #define IMX7ULP_FCR 0x58 50 #define IMX7ULP_FSR 0x5c 51 #define IMX7ULP_TCR 0x60 52 #define IMX7ULP_TDR 0x64 53 #define IMX7ULP_RSR 0x70 54 #define IMX7ULP_RDR 0x74 55 56 /* General control register field define */ 57 #define CR_RRF BIT(9) 58 #define CR_RTF BIT(8) 59 #define CR_RST BIT(1) 60 #define CR_MEN BIT(0) 61 #define SR_MBF BIT(24) 62 #define SR_TCF BIT(10) 63 #define SR_FCF BIT(9) 64 #define SR_RDF BIT(1) 65 #define SR_TDF BIT(0) 66 #define IER_TCIE BIT(10) 67 #define IER_FCIE BIT(9) 68 #define IER_RDIE BIT(1) 69 #define IER_TDIE BIT(0) 70 #define DER_RDDE BIT(1) 71 #define DER_TDDE BIT(0) 72 #define CFGR1_PCSCFG BIT(27) 73 #define CFGR1_PINCFG (BIT(24)|BIT(25)) 74 #define CFGR1_PCSPOL BIT(8) 75 #define CFGR1_NOSTALL BIT(3) 76 #define CFGR1_MASTER BIT(0) 77 #define FSR_TXCOUNT (0xFF) 78 #define RSR_RXEMPTY BIT(1) 79 #define TCR_CPOL BIT(31) 80 #define TCR_CPHA BIT(30) 81 #define TCR_CONT BIT(21) 82 #define TCR_CONTC BIT(20) 83 #define TCR_RXMSK BIT(19) 84 #define TCR_TXMSK BIT(18) 85 86 struct lpspi_config { 87 u8 bpw; 88 u8 chip_select; 89 u8 prescale; 90 u16 mode; 91 u32 speed_hz; 92 }; 93 94 struct fsl_lpspi_data { 95 struct device *dev; 96 void __iomem *base; 97 unsigned long base_phys; 98 struct clk *clk_ipg; 99 struct clk *clk_per; 100 bool is_slave; 101 u32 num_cs; 102 bool is_only_cs1; 103 bool is_first_byte; 104 105 void *rx_buf; 106 const void *tx_buf; 107 void (*tx)(struct fsl_lpspi_data *); 108 void (*rx)(struct fsl_lpspi_data *); 109 110 u32 remain; 111 u8 watermark; 112 u8 txfifosize; 113 u8 rxfifosize; 114 115 struct lpspi_config config; 116 struct completion xfer_done; 117 118 bool slave_aborted; 119 120 /* DMA */ 121 bool usedma; 122 struct completion dma_rx_completion; 123 struct completion dma_tx_completion; 124 }; 125 126 static const struct of_device_id fsl_lpspi_dt_ids[] = { 127 { .compatible = "fsl,imx7ulp-spi", }, 128 { /* sentinel */ } 129 }; 130 MODULE_DEVICE_TABLE(of, fsl_lpspi_dt_ids); 131 132 #define LPSPI_BUF_RX(type) \ 133 static void fsl_lpspi_buf_rx_##type(struct fsl_lpspi_data *fsl_lpspi) \ 134 { \ 135 unsigned int val = readl(fsl_lpspi->base + IMX7ULP_RDR); \ 136 \ 137 if (fsl_lpspi->rx_buf) { \ 138 *(type *)fsl_lpspi->rx_buf = val; \ 139 fsl_lpspi->rx_buf += sizeof(type); \ 140 } \ 141 } 142 143 #define LPSPI_BUF_TX(type) \ 144 static void fsl_lpspi_buf_tx_##type(struct fsl_lpspi_data *fsl_lpspi) \ 145 { \ 146 type val = 0; \ 147 \ 148 if (fsl_lpspi->tx_buf) { \ 149 val = *(type *)fsl_lpspi->tx_buf; \ 150 fsl_lpspi->tx_buf += sizeof(type); \ 151 } \ 152 \ 153 fsl_lpspi->remain -= sizeof(type); \ 154 writel(val, fsl_lpspi->base + IMX7ULP_TDR); \ 155 } 156 157 LPSPI_BUF_RX(u8) 158 LPSPI_BUF_TX(u8) 159 LPSPI_BUF_RX(u16) 160 LPSPI_BUF_TX(u16) 161 LPSPI_BUF_RX(u32) 162 LPSPI_BUF_TX(u32) 163 164 static void fsl_lpspi_intctrl(struct fsl_lpspi_data *fsl_lpspi, 165 unsigned int enable) 166 { 167 writel(enable, fsl_lpspi->base + IMX7ULP_IER); 168 } 169 170 static int fsl_lpspi_bytes_per_word(const int bpw) 171 { 172 return DIV_ROUND_UP(bpw, BITS_PER_BYTE); 173 } 174 175 static bool fsl_lpspi_can_dma(struct spi_controller *controller, 176 struct spi_device *spi, 177 struct spi_transfer *transfer) 178 { 179 unsigned int bytes_per_word; 180 181 if (!controller->dma_rx) 182 return false; 183 184 bytes_per_word = fsl_lpspi_bytes_per_word(transfer->bits_per_word); 185 186 switch (bytes_per_word) { 187 case 1: 188 case 2: 189 case 4: 190 break; 191 default: 192 return false; 193 } 194 195 return true; 196 } 197 198 static int lpspi_prepare_xfer_hardware(struct spi_controller *controller) 199 { 200 struct fsl_lpspi_data *fsl_lpspi = 201 spi_controller_get_devdata(controller); 202 int ret; 203 204 ret = pm_runtime_resume_and_get(fsl_lpspi->dev); 205 if (ret < 0) { 206 dev_err(fsl_lpspi->dev, "failed to enable clock\n"); 207 return ret; 208 } 209 210 return 0; 211 } 212 213 static int lpspi_unprepare_xfer_hardware(struct spi_controller *controller) 214 { 215 struct fsl_lpspi_data *fsl_lpspi = 216 spi_controller_get_devdata(controller); 217 218 pm_runtime_mark_last_busy(fsl_lpspi->dev); 219 pm_runtime_put_autosuspend(fsl_lpspi->dev); 220 221 return 0; 222 } 223 224 static void fsl_lpspi_write_tx_fifo(struct fsl_lpspi_data *fsl_lpspi) 225 { 226 u8 txfifo_cnt; 227 u32 temp; 228 229 txfifo_cnt = readl(fsl_lpspi->base + IMX7ULP_FSR) & 0xff; 230 231 while (txfifo_cnt < fsl_lpspi->txfifosize) { 232 if (!fsl_lpspi->remain) 233 break; 234 fsl_lpspi->tx(fsl_lpspi); 235 txfifo_cnt++; 236 } 237 238 if (txfifo_cnt < fsl_lpspi->txfifosize) { 239 if (!fsl_lpspi->is_slave) { 240 temp = readl(fsl_lpspi->base + IMX7ULP_TCR); 241 temp &= ~TCR_CONTC; 242 writel(temp, fsl_lpspi->base + IMX7ULP_TCR); 243 } 244 245 fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE); 246 } else 247 fsl_lpspi_intctrl(fsl_lpspi, IER_TDIE); 248 } 249 250 static void fsl_lpspi_read_rx_fifo(struct fsl_lpspi_data *fsl_lpspi) 251 { 252 while (!(readl(fsl_lpspi->base + IMX7ULP_RSR) & RSR_RXEMPTY)) 253 fsl_lpspi->rx(fsl_lpspi); 254 } 255 256 static void fsl_lpspi_set_cmd(struct fsl_lpspi_data *fsl_lpspi) 257 { 258 u32 temp = 0; 259 260 temp |= fsl_lpspi->config.bpw - 1; 261 temp |= (fsl_lpspi->config.mode & 0x3) << 30; 262 temp |= (fsl_lpspi->config.chip_select & 0x3) << 24; 263 if (!fsl_lpspi->is_slave) { 264 temp |= fsl_lpspi->config.prescale << 27; 265 /* 266 * Set TCR_CONT will keep SS asserted after current transfer. 267 * For the first transfer, clear TCR_CONTC to assert SS. 268 * For subsequent transfer, set TCR_CONTC to keep SS asserted. 269 */ 270 if (!fsl_lpspi->usedma) { 271 temp |= TCR_CONT; 272 if (fsl_lpspi->is_first_byte) 273 temp &= ~TCR_CONTC; 274 else 275 temp |= TCR_CONTC; 276 } 277 } 278 writel(temp, fsl_lpspi->base + IMX7ULP_TCR); 279 280 dev_dbg(fsl_lpspi->dev, "TCR=0x%x\n", temp); 281 } 282 283 static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi) 284 { 285 u32 temp; 286 287 if (!fsl_lpspi->usedma) 288 temp = fsl_lpspi->watermark >> 1 | 289 (fsl_lpspi->watermark >> 1) << 16; 290 else 291 temp = fsl_lpspi->watermark >> 1; 292 293 writel(temp, fsl_lpspi->base + IMX7ULP_FCR); 294 295 dev_dbg(fsl_lpspi->dev, "FCR=0x%x\n", temp); 296 } 297 298 static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi) 299 { 300 struct lpspi_config config = fsl_lpspi->config; 301 unsigned int perclk_rate, scldiv; 302 u8 prescale; 303 304 perclk_rate = clk_get_rate(fsl_lpspi->clk_per); 305 306 if (!config.speed_hz) { 307 dev_err(fsl_lpspi->dev, 308 "error: the transmission speed provided is 0!\n"); 309 return -EINVAL; 310 } 311 312 if (config.speed_hz > perclk_rate / 2) { 313 dev_err(fsl_lpspi->dev, 314 "per-clk should be at least two times of transfer speed"); 315 return -EINVAL; 316 } 317 318 for (prescale = 0; prescale < 8; prescale++) { 319 scldiv = perclk_rate / config.speed_hz / (1 << prescale) - 2; 320 if (scldiv < 256) { 321 fsl_lpspi->config.prescale = prescale; 322 break; 323 } 324 } 325 326 if (scldiv >= 256) 327 return -EINVAL; 328 329 writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16), 330 fsl_lpspi->base + IMX7ULP_CCR); 331 332 dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale=%d, scldiv=%d\n", 333 perclk_rate, config.speed_hz, prescale, scldiv); 334 335 return 0; 336 } 337 338 static int fsl_lpspi_dma_configure(struct spi_controller *controller) 339 { 340 int ret; 341 enum dma_slave_buswidth buswidth; 342 struct dma_slave_config rx = {}, tx = {}; 343 struct fsl_lpspi_data *fsl_lpspi = 344 spi_controller_get_devdata(controller); 345 346 switch (fsl_lpspi_bytes_per_word(fsl_lpspi->config.bpw)) { 347 case 4: 348 buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; 349 break; 350 case 2: 351 buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; 352 break; 353 case 1: 354 buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; 355 break; 356 default: 357 return -EINVAL; 358 } 359 360 tx.direction = DMA_MEM_TO_DEV; 361 tx.dst_addr = fsl_lpspi->base_phys + IMX7ULP_TDR; 362 tx.dst_addr_width = buswidth; 363 tx.dst_maxburst = 1; 364 ret = dmaengine_slave_config(controller->dma_tx, &tx); 365 if (ret) { 366 dev_err(fsl_lpspi->dev, "TX dma configuration failed with %d\n", 367 ret); 368 return ret; 369 } 370 371 rx.direction = DMA_DEV_TO_MEM; 372 rx.src_addr = fsl_lpspi->base_phys + IMX7ULP_RDR; 373 rx.src_addr_width = buswidth; 374 rx.src_maxburst = 1; 375 ret = dmaengine_slave_config(controller->dma_rx, &rx); 376 if (ret) { 377 dev_err(fsl_lpspi->dev, "RX dma configuration failed with %d\n", 378 ret); 379 return ret; 380 } 381 382 return 0; 383 } 384 385 static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi) 386 { 387 u32 temp; 388 int ret; 389 390 if (!fsl_lpspi->is_slave) { 391 ret = fsl_lpspi_set_bitrate(fsl_lpspi); 392 if (ret) 393 return ret; 394 } 395 396 fsl_lpspi_set_watermark(fsl_lpspi); 397 398 if (!fsl_lpspi->is_slave) 399 temp = CFGR1_MASTER; 400 else 401 temp = CFGR1_PINCFG; 402 if (fsl_lpspi->config.mode & SPI_CS_HIGH) 403 temp |= CFGR1_PCSPOL; 404 writel(temp, fsl_lpspi->base + IMX7ULP_CFGR1); 405 406 temp = readl(fsl_lpspi->base + IMX7ULP_CR); 407 temp |= CR_RRF | CR_RTF | CR_MEN; 408 writel(temp, fsl_lpspi->base + IMX7ULP_CR); 409 410 temp = 0; 411 if (fsl_lpspi->usedma) 412 temp = DER_TDDE | DER_RDDE; 413 writel(temp, fsl_lpspi->base + IMX7ULP_DER); 414 415 return 0; 416 } 417 418 static int fsl_lpspi_setup_transfer(struct spi_controller *controller, 419 struct spi_device *spi, 420 struct spi_transfer *t) 421 { 422 struct fsl_lpspi_data *fsl_lpspi = 423 spi_controller_get_devdata(spi->controller); 424 425 if (t == NULL) 426 return -EINVAL; 427 428 fsl_lpspi->config.mode = spi->mode; 429 fsl_lpspi->config.bpw = t->bits_per_word; 430 fsl_lpspi->config.speed_hz = t->speed_hz; 431 if (fsl_lpspi->is_only_cs1) 432 fsl_lpspi->config.chip_select = 1; 433 else 434 fsl_lpspi->config.chip_select = spi_get_chipselect(spi, 0); 435 436 if (!fsl_lpspi->config.speed_hz) 437 fsl_lpspi->config.speed_hz = spi->max_speed_hz; 438 if (!fsl_lpspi->config.bpw) 439 fsl_lpspi->config.bpw = spi->bits_per_word; 440 441 /* Initialize the functions for transfer */ 442 if (fsl_lpspi->config.bpw <= 8) { 443 fsl_lpspi->rx = fsl_lpspi_buf_rx_u8; 444 fsl_lpspi->tx = fsl_lpspi_buf_tx_u8; 445 } else if (fsl_lpspi->config.bpw <= 16) { 446 fsl_lpspi->rx = fsl_lpspi_buf_rx_u16; 447 fsl_lpspi->tx = fsl_lpspi_buf_tx_u16; 448 } else { 449 fsl_lpspi->rx = fsl_lpspi_buf_rx_u32; 450 fsl_lpspi->tx = fsl_lpspi_buf_tx_u32; 451 } 452 453 if (t->len <= fsl_lpspi->txfifosize) 454 fsl_lpspi->watermark = t->len; 455 else 456 fsl_lpspi->watermark = fsl_lpspi->txfifosize; 457 458 if (fsl_lpspi_can_dma(controller, spi, t)) 459 fsl_lpspi->usedma = true; 460 else 461 fsl_lpspi->usedma = false; 462 463 return fsl_lpspi_config(fsl_lpspi); 464 } 465 466 static int fsl_lpspi_slave_abort(struct spi_controller *controller) 467 { 468 struct fsl_lpspi_data *fsl_lpspi = 469 spi_controller_get_devdata(controller); 470 471 fsl_lpspi->slave_aborted = true; 472 if (!fsl_lpspi->usedma) 473 complete(&fsl_lpspi->xfer_done); 474 else { 475 complete(&fsl_lpspi->dma_tx_completion); 476 complete(&fsl_lpspi->dma_rx_completion); 477 } 478 479 return 0; 480 } 481 482 static int fsl_lpspi_wait_for_completion(struct spi_controller *controller) 483 { 484 struct fsl_lpspi_data *fsl_lpspi = 485 spi_controller_get_devdata(controller); 486 487 if (fsl_lpspi->is_slave) { 488 if (wait_for_completion_interruptible(&fsl_lpspi->xfer_done) || 489 fsl_lpspi->slave_aborted) { 490 dev_dbg(fsl_lpspi->dev, "interrupted\n"); 491 return -EINTR; 492 } 493 } else { 494 if (!wait_for_completion_timeout(&fsl_lpspi->xfer_done, HZ)) { 495 dev_dbg(fsl_lpspi->dev, "wait for completion timeout\n"); 496 return -ETIMEDOUT; 497 } 498 } 499 500 return 0; 501 } 502 503 static int fsl_lpspi_reset(struct fsl_lpspi_data *fsl_lpspi) 504 { 505 u32 temp; 506 507 if (!fsl_lpspi->usedma) { 508 /* Disable all interrupt */ 509 fsl_lpspi_intctrl(fsl_lpspi, 0); 510 } 511 512 /* W1C for all flags in SR */ 513 temp = 0x3F << 8; 514 writel(temp, fsl_lpspi->base + IMX7ULP_SR); 515 516 /* Clear FIFO and disable module */ 517 temp = CR_RRF | CR_RTF; 518 writel(temp, fsl_lpspi->base + IMX7ULP_CR); 519 520 return 0; 521 } 522 523 static void fsl_lpspi_dma_rx_callback(void *cookie) 524 { 525 struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie; 526 527 complete(&fsl_lpspi->dma_rx_completion); 528 } 529 530 static void fsl_lpspi_dma_tx_callback(void *cookie) 531 { 532 struct fsl_lpspi_data *fsl_lpspi = (struct fsl_lpspi_data *)cookie; 533 534 complete(&fsl_lpspi->dma_tx_completion); 535 } 536 537 static int fsl_lpspi_calculate_timeout(struct fsl_lpspi_data *fsl_lpspi, 538 int size) 539 { 540 unsigned long timeout = 0; 541 542 /* Time with actual data transfer and CS change delay related to HW */ 543 timeout = (8 + 4) * size / fsl_lpspi->config.speed_hz; 544 545 /* Add extra second for scheduler related activities */ 546 timeout += 1; 547 548 /* Double calculated timeout */ 549 return msecs_to_jiffies(2 * timeout * MSEC_PER_SEC); 550 } 551 552 static int fsl_lpspi_dma_transfer(struct spi_controller *controller, 553 struct fsl_lpspi_data *fsl_lpspi, 554 struct spi_transfer *transfer) 555 { 556 struct dma_async_tx_descriptor *desc_tx, *desc_rx; 557 unsigned long transfer_timeout; 558 unsigned long timeout; 559 struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg; 560 int ret; 561 562 ret = fsl_lpspi_dma_configure(controller); 563 if (ret) 564 return ret; 565 566 desc_rx = dmaengine_prep_slave_sg(controller->dma_rx, 567 rx->sgl, rx->nents, DMA_DEV_TO_MEM, 568 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 569 if (!desc_rx) 570 return -EINVAL; 571 572 desc_rx->callback = fsl_lpspi_dma_rx_callback; 573 desc_rx->callback_param = (void *)fsl_lpspi; 574 dmaengine_submit(desc_rx); 575 reinit_completion(&fsl_lpspi->dma_rx_completion); 576 dma_async_issue_pending(controller->dma_rx); 577 578 desc_tx = dmaengine_prep_slave_sg(controller->dma_tx, 579 tx->sgl, tx->nents, DMA_MEM_TO_DEV, 580 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 581 if (!desc_tx) { 582 dmaengine_terminate_all(controller->dma_tx); 583 return -EINVAL; 584 } 585 586 desc_tx->callback = fsl_lpspi_dma_tx_callback; 587 desc_tx->callback_param = (void *)fsl_lpspi; 588 dmaengine_submit(desc_tx); 589 reinit_completion(&fsl_lpspi->dma_tx_completion); 590 dma_async_issue_pending(controller->dma_tx); 591 592 fsl_lpspi->slave_aborted = false; 593 594 if (!fsl_lpspi->is_slave) { 595 transfer_timeout = fsl_lpspi_calculate_timeout(fsl_lpspi, 596 transfer->len); 597 598 /* Wait eDMA to finish the data transfer.*/ 599 timeout = wait_for_completion_timeout(&fsl_lpspi->dma_tx_completion, 600 transfer_timeout); 601 if (!timeout) { 602 dev_err(fsl_lpspi->dev, "I/O Error in DMA TX\n"); 603 dmaengine_terminate_all(controller->dma_tx); 604 dmaengine_terminate_all(controller->dma_rx); 605 fsl_lpspi_reset(fsl_lpspi); 606 return -ETIMEDOUT; 607 } 608 609 timeout = wait_for_completion_timeout(&fsl_lpspi->dma_rx_completion, 610 transfer_timeout); 611 if (!timeout) { 612 dev_err(fsl_lpspi->dev, "I/O Error in DMA RX\n"); 613 dmaengine_terminate_all(controller->dma_tx); 614 dmaengine_terminate_all(controller->dma_rx); 615 fsl_lpspi_reset(fsl_lpspi); 616 return -ETIMEDOUT; 617 } 618 } else { 619 if (wait_for_completion_interruptible(&fsl_lpspi->dma_tx_completion) || 620 fsl_lpspi->slave_aborted) { 621 dev_dbg(fsl_lpspi->dev, 622 "I/O Error in DMA TX interrupted\n"); 623 dmaengine_terminate_all(controller->dma_tx); 624 dmaengine_terminate_all(controller->dma_rx); 625 fsl_lpspi_reset(fsl_lpspi); 626 return -EINTR; 627 } 628 629 if (wait_for_completion_interruptible(&fsl_lpspi->dma_rx_completion) || 630 fsl_lpspi->slave_aborted) { 631 dev_dbg(fsl_lpspi->dev, 632 "I/O Error in DMA RX interrupted\n"); 633 dmaengine_terminate_all(controller->dma_tx); 634 dmaengine_terminate_all(controller->dma_rx); 635 fsl_lpspi_reset(fsl_lpspi); 636 return -EINTR; 637 } 638 } 639 640 fsl_lpspi_reset(fsl_lpspi); 641 642 return 0; 643 } 644 645 static void fsl_lpspi_dma_exit(struct spi_controller *controller) 646 { 647 if (controller->dma_rx) { 648 dma_release_channel(controller->dma_rx); 649 controller->dma_rx = NULL; 650 } 651 652 if (controller->dma_tx) { 653 dma_release_channel(controller->dma_tx); 654 controller->dma_tx = NULL; 655 } 656 } 657 658 static int fsl_lpspi_dma_init(struct device *dev, 659 struct fsl_lpspi_data *fsl_lpspi, 660 struct spi_controller *controller) 661 { 662 int ret; 663 664 /* Prepare for TX DMA: */ 665 controller->dma_tx = dma_request_chan(dev, "tx"); 666 if (IS_ERR(controller->dma_tx)) { 667 ret = PTR_ERR(controller->dma_tx); 668 dev_dbg(dev, "can't get the TX DMA channel, error %d!\n", ret); 669 controller->dma_tx = NULL; 670 goto err; 671 } 672 673 /* Prepare for RX DMA: */ 674 controller->dma_rx = dma_request_chan(dev, "rx"); 675 if (IS_ERR(controller->dma_rx)) { 676 ret = PTR_ERR(controller->dma_rx); 677 dev_dbg(dev, "can't get the RX DMA channel, error %d\n", ret); 678 controller->dma_rx = NULL; 679 goto err; 680 } 681 682 init_completion(&fsl_lpspi->dma_rx_completion); 683 init_completion(&fsl_lpspi->dma_tx_completion); 684 controller->can_dma = fsl_lpspi_can_dma; 685 controller->max_dma_len = FSL_LPSPI_MAX_EDMA_BYTES; 686 687 return 0; 688 err: 689 fsl_lpspi_dma_exit(controller); 690 return ret; 691 } 692 693 static int fsl_lpspi_pio_transfer(struct spi_controller *controller, 694 struct spi_transfer *t) 695 { 696 struct fsl_lpspi_data *fsl_lpspi = 697 spi_controller_get_devdata(controller); 698 int ret; 699 700 fsl_lpspi->tx_buf = t->tx_buf; 701 fsl_lpspi->rx_buf = t->rx_buf; 702 fsl_lpspi->remain = t->len; 703 704 reinit_completion(&fsl_lpspi->xfer_done); 705 fsl_lpspi->slave_aborted = false; 706 707 fsl_lpspi_write_tx_fifo(fsl_lpspi); 708 709 ret = fsl_lpspi_wait_for_completion(controller); 710 if (ret) 711 return ret; 712 713 fsl_lpspi_reset(fsl_lpspi); 714 715 return 0; 716 } 717 718 static int fsl_lpspi_transfer_one(struct spi_controller *controller, 719 struct spi_device *spi, 720 struct spi_transfer *t) 721 { 722 struct fsl_lpspi_data *fsl_lpspi = 723 spi_controller_get_devdata(controller); 724 int ret; 725 726 fsl_lpspi->is_first_byte = true; 727 ret = fsl_lpspi_setup_transfer(controller, spi, t); 728 if (ret < 0) 729 return ret; 730 731 fsl_lpspi_set_cmd(fsl_lpspi); 732 fsl_lpspi->is_first_byte = false; 733 734 if (fsl_lpspi->usedma) 735 ret = fsl_lpspi_dma_transfer(controller, fsl_lpspi, t); 736 else 737 ret = fsl_lpspi_pio_transfer(controller, t); 738 if (ret < 0) 739 return ret; 740 741 return 0; 742 } 743 744 static irqreturn_t fsl_lpspi_isr(int irq, void *dev_id) 745 { 746 u32 temp_SR, temp_IER; 747 struct fsl_lpspi_data *fsl_lpspi = dev_id; 748 749 temp_IER = readl(fsl_lpspi->base + IMX7ULP_IER); 750 fsl_lpspi_intctrl(fsl_lpspi, 0); 751 temp_SR = readl(fsl_lpspi->base + IMX7ULP_SR); 752 753 fsl_lpspi_read_rx_fifo(fsl_lpspi); 754 755 if ((temp_SR & SR_TDF) && (temp_IER & IER_TDIE)) { 756 fsl_lpspi_write_tx_fifo(fsl_lpspi); 757 return IRQ_HANDLED; 758 } 759 760 if (temp_SR & SR_MBF || 761 readl(fsl_lpspi->base + IMX7ULP_FSR) & FSR_TXCOUNT) { 762 writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR); 763 fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE); 764 return IRQ_HANDLED; 765 } 766 767 if (temp_SR & SR_FCF && (temp_IER & IER_FCIE)) { 768 writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR); 769 complete(&fsl_lpspi->xfer_done); 770 return IRQ_HANDLED; 771 } 772 773 return IRQ_NONE; 774 } 775 776 #ifdef CONFIG_PM 777 static int fsl_lpspi_runtime_resume(struct device *dev) 778 { 779 struct spi_controller *controller = dev_get_drvdata(dev); 780 struct fsl_lpspi_data *fsl_lpspi; 781 int ret; 782 783 fsl_lpspi = spi_controller_get_devdata(controller); 784 785 ret = clk_prepare_enable(fsl_lpspi->clk_per); 786 if (ret) 787 return ret; 788 789 ret = clk_prepare_enable(fsl_lpspi->clk_ipg); 790 if (ret) { 791 clk_disable_unprepare(fsl_lpspi->clk_per); 792 return ret; 793 } 794 795 return 0; 796 } 797 798 static int fsl_lpspi_runtime_suspend(struct device *dev) 799 { 800 struct spi_controller *controller = dev_get_drvdata(dev); 801 struct fsl_lpspi_data *fsl_lpspi; 802 803 fsl_lpspi = spi_controller_get_devdata(controller); 804 805 clk_disable_unprepare(fsl_lpspi->clk_per); 806 clk_disable_unprepare(fsl_lpspi->clk_ipg); 807 808 return 0; 809 } 810 #endif 811 812 static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi) 813 { 814 struct device *dev = fsl_lpspi->dev; 815 816 pm_runtime_enable(dev); 817 pm_runtime_set_autosuspend_delay(dev, FSL_LPSPI_RPM_TIMEOUT); 818 pm_runtime_use_autosuspend(dev); 819 820 return 0; 821 } 822 823 static int fsl_lpspi_probe(struct platform_device *pdev) 824 { 825 struct fsl_lpspi_data *fsl_lpspi; 826 struct spi_controller *controller; 827 struct resource *res; 828 int ret, irq; 829 u32 temp; 830 bool is_slave; 831 832 is_slave = of_property_read_bool((&pdev->dev)->of_node, "spi-slave"); 833 if (is_slave) 834 controller = spi_alloc_slave(&pdev->dev, 835 sizeof(struct fsl_lpspi_data)); 836 else 837 controller = spi_alloc_master(&pdev->dev, 838 sizeof(struct fsl_lpspi_data)); 839 840 if (!controller) 841 return -ENOMEM; 842 843 platform_set_drvdata(pdev, controller); 844 845 fsl_lpspi = spi_controller_get_devdata(controller); 846 fsl_lpspi->dev = &pdev->dev; 847 fsl_lpspi->is_slave = is_slave; 848 fsl_lpspi->is_only_cs1 = of_property_read_bool((&pdev->dev)->of_node, 849 "fsl,spi-only-use-cs1-sel"); 850 if (of_property_read_u32((&pdev->dev)->of_node, "num-cs", 851 &fsl_lpspi->num_cs)) 852 fsl_lpspi->num_cs = 1; 853 854 controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32); 855 controller->transfer_one = fsl_lpspi_transfer_one; 856 controller->prepare_transfer_hardware = lpspi_prepare_xfer_hardware; 857 controller->unprepare_transfer_hardware = lpspi_unprepare_xfer_hardware; 858 controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; 859 controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX; 860 controller->dev.of_node = pdev->dev.of_node; 861 controller->bus_num = pdev->id; 862 controller->num_chipselect = fsl_lpspi->num_cs; 863 controller->slave_abort = fsl_lpspi_slave_abort; 864 if (!fsl_lpspi->is_slave) 865 controller->use_gpio_descriptors = true; 866 867 init_completion(&fsl_lpspi->xfer_done); 868 869 fsl_lpspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 870 if (IS_ERR(fsl_lpspi->base)) { 871 ret = PTR_ERR(fsl_lpspi->base); 872 goto out_controller_put; 873 } 874 fsl_lpspi->base_phys = res->start; 875 876 irq = platform_get_irq(pdev, 0); 877 if (irq < 0) { 878 ret = irq; 879 goto out_controller_put; 880 } 881 882 ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0, 883 dev_name(&pdev->dev), fsl_lpspi); 884 if (ret) { 885 dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret); 886 goto out_controller_put; 887 } 888 889 fsl_lpspi->clk_per = devm_clk_get(&pdev->dev, "per"); 890 if (IS_ERR(fsl_lpspi->clk_per)) { 891 ret = PTR_ERR(fsl_lpspi->clk_per); 892 goto out_controller_put; 893 } 894 895 fsl_lpspi->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); 896 if (IS_ERR(fsl_lpspi->clk_ipg)) { 897 ret = PTR_ERR(fsl_lpspi->clk_ipg); 898 goto out_controller_put; 899 } 900 901 /* enable the clock */ 902 ret = fsl_lpspi_init_rpm(fsl_lpspi); 903 if (ret) 904 goto out_controller_put; 905 906 ret = pm_runtime_get_sync(fsl_lpspi->dev); 907 if (ret < 0) { 908 dev_err(fsl_lpspi->dev, "failed to enable clock\n"); 909 goto out_pm_get; 910 } 911 912 temp = readl(fsl_lpspi->base + IMX7ULP_PARAM); 913 fsl_lpspi->txfifosize = 1 << (temp & 0x0f); 914 fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f); 915 916 ret = fsl_lpspi_dma_init(&pdev->dev, fsl_lpspi, controller); 917 if (ret == -EPROBE_DEFER) 918 goto out_pm_get; 919 if (ret < 0) 920 dev_warn(&pdev->dev, "dma setup error %d, use pio\n", ret); 921 else 922 /* 923 * disable LPSPI module IRQ when enable DMA mode successfully, 924 * to prevent the unexpected LPSPI module IRQ events. 925 */ 926 disable_irq(irq); 927 928 ret = devm_spi_register_controller(&pdev->dev, controller); 929 if (ret < 0) { 930 dev_err_probe(&pdev->dev, ret, "spi_register_controller error\n"); 931 goto free_dma; 932 } 933 934 pm_runtime_mark_last_busy(fsl_lpspi->dev); 935 pm_runtime_put_autosuspend(fsl_lpspi->dev); 936 937 return 0; 938 939 free_dma: 940 fsl_lpspi_dma_exit(controller); 941 out_pm_get: 942 pm_runtime_dont_use_autosuspend(fsl_lpspi->dev); 943 pm_runtime_put_sync(fsl_lpspi->dev); 944 pm_runtime_disable(fsl_lpspi->dev); 945 out_controller_put: 946 spi_controller_put(controller); 947 948 return ret; 949 } 950 951 static void fsl_lpspi_remove(struct platform_device *pdev) 952 { 953 struct spi_controller *controller = platform_get_drvdata(pdev); 954 struct fsl_lpspi_data *fsl_lpspi = 955 spi_controller_get_devdata(controller); 956 957 fsl_lpspi_dma_exit(controller); 958 959 pm_runtime_disable(fsl_lpspi->dev); 960 } 961 962 static int __maybe_unused fsl_lpspi_suspend(struct device *dev) 963 { 964 pinctrl_pm_select_sleep_state(dev); 965 return pm_runtime_force_suspend(dev); 966 } 967 968 static int __maybe_unused fsl_lpspi_resume(struct device *dev) 969 { 970 int ret; 971 972 ret = pm_runtime_force_resume(dev); 973 if (ret) { 974 dev_err(dev, "Error in resume: %d\n", ret); 975 return ret; 976 } 977 978 pinctrl_pm_select_default_state(dev); 979 980 return 0; 981 } 982 983 static const struct dev_pm_ops fsl_lpspi_pm_ops = { 984 SET_RUNTIME_PM_OPS(fsl_lpspi_runtime_suspend, 985 fsl_lpspi_runtime_resume, NULL) 986 SET_SYSTEM_SLEEP_PM_OPS(fsl_lpspi_suspend, fsl_lpspi_resume) 987 }; 988 989 static struct platform_driver fsl_lpspi_driver = { 990 .driver = { 991 .name = DRIVER_NAME, 992 .of_match_table = fsl_lpspi_dt_ids, 993 .pm = &fsl_lpspi_pm_ops, 994 }, 995 .probe = fsl_lpspi_probe, 996 .remove_new = fsl_lpspi_remove, 997 }; 998 module_platform_driver(fsl_lpspi_driver); 999 1000 MODULE_DESCRIPTION("LPSPI Controller driver"); 1001 MODULE_AUTHOR("Gao Pan <pandy.gao@nxp.com>"); 1002 MODULE_LICENSE("GPL"); 1003