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