1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Driver for Atmel AT32 and AT91 SPI Controllers 4 * 5 * Copyright (C) 2006 Atmel Corporation 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/clk.h> 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/delay.h> 13 #include <linux/dma-mapping.h> 14 #include <linux/dmaengine.h> 15 #include <linux/err.h> 16 #include <linux/interrupt.h> 17 #include <linux/spi/spi.h> 18 #include <linux/slab.h> 19 #include <linux/of.h> 20 21 #include <linux/io.h> 22 #include <linux/gpio/consumer.h> 23 #include <linux/pinctrl/consumer.h> 24 #include <linux/pm_runtime.h> 25 #include <trace/events/spi.h> 26 27 /* SPI register offsets */ 28 #define SPI_CR 0x0000 29 #define SPI_MR 0x0004 30 #define SPI_RDR 0x0008 31 #define SPI_TDR 0x000c 32 #define SPI_SR 0x0010 33 #define SPI_IER 0x0014 34 #define SPI_IDR 0x0018 35 #define SPI_IMR 0x001c 36 #define SPI_CSR0 0x0030 37 #define SPI_CSR1 0x0034 38 #define SPI_CSR2 0x0038 39 #define SPI_CSR3 0x003c 40 #define SPI_FMR 0x0040 41 #define SPI_FLR 0x0044 42 #define SPI_VERSION 0x00fc 43 #define SPI_RPR 0x0100 44 #define SPI_RCR 0x0104 45 #define SPI_TPR 0x0108 46 #define SPI_TCR 0x010c 47 #define SPI_RNPR 0x0110 48 #define SPI_RNCR 0x0114 49 #define SPI_TNPR 0x0118 50 #define SPI_TNCR 0x011c 51 #define SPI_PTCR 0x0120 52 #define SPI_PTSR 0x0124 53 54 /* Bitfields in CR */ 55 #define SPI_SPIEN_OFFSET 0 56 #define SPI_SPIEN_SIZE 1 57 #define SPI_SPIDIS_OFFSET 1 58 #define SPI_SPIDIS_SIZE 1 59 #define SPI_SWRST_OFFSET 7 60 #define SPI_SWRST_SIZE 1 61 #define SPI_LASTXFER_OFFSET 24 62 #define SPI_LASTXFER_SIZE 1 63 #define SPI_TXFCLR_OFFSET 16 64 #define SPI_TXFCLR_SIZE 1 65 #define SPI_RXFCLR_OFFSET 17 66 #define SPI_RXFCLR_SIZE 1 67 #define SPI_FIFOEN_OFFSET 30 68 #define SPI_FIFOEN_SIZE 1 69 #define SPI_FIFODIS_OFFSET 31 70 #define SPI_FIFODIS_SIZE 1 71 72 /* Bitfields in MR */ 73 #define SPI_MSTR_OFFSET 0 74 #define SPI_MSTR_SIZE 1 75 #define SPI_PS_OFFSET 1 76 #define SPI_PS_SIZE 1 77 #define SPI_PCSDEC_OFFSET 2 78 #define SPI_PCSDEC_SIZE 1 79 #define SPI_FDIV_OFFSET 3 80 #define SPI_FDIV_SIZE 1 81 #define SPI_MODFDIS_OFFSET 4 82 #define SPI_MODFDIS_SIZE 1 83 #define SPI_WDRBT_OFFSET 5 84 #define SPI_WDRBT_SIZE 1 85 #define SPI_LLB_OFFSET 7 86 #define SPI_LLB_SIZE 1 87 #define SPI_PCS_OFFSET 16 88 #define SPI_PCS_SIZE 4 89 #define SPI_DLYBCS_OFFSET 24 90 #define SPI_DLYBCS_SIZE 8 91 92 /* Bitfields in RDR */ 93 #define SPI_RD_OFFSET 0 94 #define SPI_RD_SIZE 16 95 96 /* Bitfields in TDR */ 97 #define SPI_TD_OFFSET 0 98 #define SPI_TD_SIZE 16 99 100 /* Bitfields in SR */ 101 #define SPI_RDRF_OFFSET 0 102 #define SPI_RDRF_SIZE 1 103 #define SPI_TDRE_OFFSET 1 104 #define SPI_TDRE_SIZE 1 105 #define SPI_MODF_OFFSET 2 106 #define SPI_MODF_SIZE 1 107 #define SPI_OVRES_OFFSET 3 108 #define SPI_OVRES_SIZE 1 109 #define SPI_ENDRX_OFFSET 4 110 #define SPI_ENDRX_SIZE 1 111 #define SPI_ENDTX_OFFSET 5 112 #define SPI_ENDTX_SIZE 1 113 #define SPI_RXBUFF_OFFSET 6 114 #define SPI_RXBUFF_SIZE 1 115 #define SPI_TXBUFE_OFFSET 7 116 #define SPI_TXBUFE_SIZE 1 117 #define SPI_NSSR_OFFSET 8 118 #define SPI_NSSR_SIZE 1 119 #define SPI_TXEMPTY_OFFSET 9 120 #define SPI_TXEMPTY_SIZE 1 121 #define SPI_SPIENS_OFFSET 16 122 #define SPI_SPIENS_SIZE 1 123 #define SPI_TXFEF_OFFSET 24 124 #define SPI_TXFEF_SIZE 1 125 #define SPI_TXFFF_OFFSET 25 126 #define SPI_TXFFF_SIZE 1 127 #define SPI_TXFTHF_OFFSET 26 128 #define SPI_TXFTHF_SIZE 1 129 #define SPI_RXFEF_OFFSET 27 130 #define SPI_RXFEF_SIZE 1 131 #define SPI_RXFFF_OFFSET 28 132 #define SPI_RXFFF_SIZE 1 133 #define SPI_RXFTHF_OFFSET 29 134 #define SPI_RXFTHF_SIZE 1 135 #define SPI_TXFPTEF_OFFSET 30 136 #define SPI_TXFPTEF_SIZE 1 137 #define SPI_RXFPTEF_OFFSET 31 138 #define SPI_RXFPTEF_SIZE 1 139 140 /* Bitfields in CSR0 */ 141 #define SPI_CPOL_OFFSET 0 142 #define SPI_CPOL_SIZE 1 143 #define SPI_NCPHA_OFFSET 1 144 #define SPI_NCPHA_SIZE 1 145 #define SPI_CSAAT_OFFSET 3 146 #define SPI_CSAAT_SIZE 1 147 #define SPI_BITS_OFFSET 4 148 #define SPI_BITS_SIZE 4 149 #define SPI_SCBR_OFFSET 8 150 #define SPI_SCBR_SIZE 8 151 #define SPI_DLYBS_OFFSET 16 152 #define SPI_DLYBS_SIZE 8 153 #define SPI_DLYBCT_OFFSET 24 154 #define SPI_DLYBCT_SIZE 8 155 156 /* Bitfields in RCR */ 157 #define SPI_RXCTR_OFFSET 0 158 #define SPI_RXCTR_SIZE 16 159 160 /* Bitfields in TCR */ 161 #define SPI_TXCTR_OFFSET 0 162 #define SPI_TXCTR_SIZE 16 163 164 /* Bitfields in RNCR */ 165 #define SPI_RXNCR_OFFSET 0 166 #define SPI_RXNCR_SIZE 16 167 168 /* Bitfields in TNCR */ 169 #define SPI_TXNCR_OFFSET 0 170 #define SPI_TXNCR_SIZE 16 171 172 /* Bitfields in PTCR */ 173 #define SPI_RXTEN_OFFSET 0 174 #define SPI_RXTEN_SIZE 1 175 #define SPI_RXTDIS_OFFSET 1 176 #define SPI_RXTDIS_SIZE 1 177 #define SPI_TXTEN_OFFSET 8 178 #define SPI_TXTEN_SIZE 1 179 #define SPI_TXTDIS_OFFSET 9 180 #define SPI_TXTDIS_SIZE 1 181 182 /* Bitfields in FMR */ 183 #define SPI_TXRDYM_OFFSET 0 184 #define SPI_TXRDYM_SIZE 2 185 #define SPI_RXRDYM_OFFSET 4 186 #define SPI_RXRDYM_SIZE 2 187 #define SPI_TXFTHRES_OFFSET 16 188 #define SPI_TXFTHRES_SIZE 6 189 #define SPI_RXFTHRES_OFFSET 24 190 #define SPI_RXFTHRES_SIZE 6 191 192 /* Bitfields in FLR */ 193 #define SPI_TXFL_OFFSET 0 194 #define SPI_TXFL_SIZE 6 195 #define SPI_RXFL_OFFSET 16 196 #define SPI_RXFL_SIZE 6 197 198 /* Constants for BITS */ 199 #define SPI_BITS_8_BPT 0 200 #define SPI_BITS_9_BPT 1 201 #define SPI_BITS_10_BPT 2 202 #define SPI_BITS_11_BPT 3 203 #define SPI_BITS_12_BPT 4 204 #define SPI_BITS_13_BPT 5 205 #define SPI_BITS_14_BPT 6 206 #define SPI_BITS_15_BPT 7 207 #define SPI_BITS_16_BPT 8 208 #define SPI_ONE_DATA 0 209 #define SPI_TWO_DATA 1 210 #define SPI_FOUR_DATA 2 211 212 /* Bit manipulation macros */ 213 #define SPI_BIT(name) \ 214 (1 << SPI_##name##_OFFSET) 215 #define SPI_BF(name, value) \ 216 (((value) & ((1 << SPI_##name##_SIZE) - 1)) << SPI_##name##_OFFSET) 217 #define SPI_BFEXT(name, value) \ 218 (((value) >> SPI_##name##_OFFSET) & ((1 << SPI_##name##_SIZE) - 1)) 219 #define SPI_BFINS(name, value, old) \ 220 (((old) & ~(((1 << SPI_##name##_SIZE) - 1) << SPI_##name##_OFFSET)) \ 221 | SPI_BF(name, value)) 222 223 /* Register access macros */ 224 #define spi_readl(port, reg) \ 225 readl_relaxed((port)->regs + SPI_##reg) 226 #define spi_writel(port, reg, value) \ 227 writel_relaxed((value), (port)->regs + SPI_##reg) 228 #define spi_writew(port, reg, value) \ 229 writew_relaxed((value), (port)->regs + SPI_##reg) 230 231 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and 232 * cache operations; better heuristics consider wordsize and bitrate. 233 */ 234 #define DMA_MIN_BYTES 16 235 236 #define SPI_DMA_TIMEOUT (msecs_to_jiffies(1000)) 237 238 #define AUTOSUSPEND_TIMEOUT 2000 239 240 struct atmel_spi_caps { 241 bool is_spi2; 242 bool has_wdrbt; 243 bool has_dma_support; 244 bool has_pdc_support; 245 }; 246 247 /* 248 * The core SPI transfer engine just talks to a register bank to set up 249 * DMA transfers; transfer queue progress is driven by IRQs. The clock 250 * framework provides the base clock, subdivided for each spi_device. 251 */ 252 struct atmel_spi { 253 spinlock_t lock; 254 unsigned long flags; 255 256 phys_addr_t phybase; 257 void __iomem *regs; 258 int irq; 259 struct clk *clk; 260 struct platform_device *pdev; 261 unsigned long spi_clk; 262 263 struct spi_transfer *current_transfer; 264 int current_remaining_bytes; 265 int done_status; 266 dma_addr_t dma_addr_rx_bbuf; 267 dma_addr_t dma_addr_tx_bbuf; 268 void *addr_rx_bbuf; 269 void *addr_tx_bbuf; 270 271 struct completion xfer_completion; 272 273 struct atmel_spi_caps caps; 274 275 bool use_dma; 276 bool use_pdc; 277 278 bool keep_cs; 279 280 u32 fifo_size; 281 u8 native_cs_free; 282 u8 native_cs_for_gpio; 283 }; 284 285 /* Controller-specific per-slave state */ 286 struct atmel_spi_device { 287 u32 csr; 288 }; 289 290 #define SPI_MAX_DMA_XFER 65535 /* true for both PDC and DMA */ 291 #define INVALID_DMA_ADDRESS 0xffffffff 292 293 /* 294 * Version 2 of the SPI controller has 295 * - CR.LASTXFER 296 * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) 297 * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) 298 * - SPI_CSRx.CSAAT 299 * - SPI_CSRx.SBCR allows faster clocking 300 */ 301 static bool atmel_spi_is_v2(struct atmel_spi *as) 302 { 303 return as->caps.is_spi2; 304 } 305 306 /* 307 * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby 308 * they assume that spi slave device state will not change on deselect, so 309 * that automagic deselection is OK. ("NPCSx rises if no data is to be 310 * transmitted") Not so! Workaround uses nCSx pins as GPIOs; or newer 311 * controllers have CSAAT and friends. 312 * 313 * Even controller newer than ar91rm9200, using GPIOs can make sens as 314 * it lets us support active-high chipselects despite the controller's 315 * belief that only active-low devices/systems exists. 316 * 317 * However, at91rm9200 has a second erratum whereby nCS0 doesn't work 318 * right when driven with GPIO. ("Mode Fault does not allow more than one 319 * Master on Chip Select 0.") No workaround exists for that ... so for 320 * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, 321 * and (c) will trigger that first erratum in some cases. 322 */ 323 324 static void cs_activate(struct atmel_spi *as, struct spi_device *spi) 325 { 326 struct atmel_spi_device *asd = spi->controller_state; 327 int chip_select; 328 u32 mr; 329 330 if (spi_get_csgpiod(spi, 0)) 331 chip_select = as->native_cs_for_gpio; 332 else 333 chip_select = spi_get_chipselect(spi, 0); 334 335 if (atmel_spi_is_v2(as)) { 336 spi_writel(as, CSR0 + 4 * chip_select, asd->csr); 337 /* For the low SPI version, there is a issue that PDC transfer 338 * on CS1,2,3 needs SPI_CSR0.BITS config as SPI_CSR1,2,3.BITS 339 */ 340 spi_writel(as, CSR0, asd->csr); 341 if (as->caps.has_wdrbt) { 342 spi_writel(as, MR, 343 SPI_BF(PCS, ~(0x01 << chip_select)) 344 | SPI_BIT(WDRBT) 345 | SPI_BIT(MODFDIS) 346 | SPI_BIT(MSTR)); 347 } else { 348 spi_writel(as, MR, 349 SPI_BF(PCS, ~(0x01 << chip_select)) 350 | SPI_BIT(MODFDIS) 351 | SPI_BIT(MSTR)); 352 } 353 354 mr = spi_readl(as, MR); 355 } else { 356 u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; 357 int i; 358 u32 csr; 359 360 /* Make sure clock polarity is correct */ 361 for (i = 0; i < spi->controller->num_chipselect; i++) { 362 csr = spi_readl(as, CSR0 + 4 * i); 363 if ((csr ^ cpol) & SPI_BIT(CPOL)) 364 spi_writel(as, CSR0 + 4 * i, 365 csr ^ SPI_BIT(CPOL)); 366 } 367 368 mr = spi_readl(as, MR); 369 mr = SPI_BFINS(PCS, ~(1 << chip_select), mr); 370 spi_writel(as, MR, mr); 371 } 372 373 dev_dbg(&spi->dev, "activate NPCS, mr %08x\n", mr); 374 } 375 376 static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) 377 { 378 int chip_select; 379 u32 mr; 380 381 if (spi_get_csgpiod(spi, 0)) 382 chip_select = as->native_cs_for_gpio; 383 else 384 chip_select = spi_get_chipselect(spi, 0); 385 386 /* only deactivate *this* device; sometimes transfers to 387 * another device may be active when this routine is called. 388 */ 389 mr = spi_readl(as, MR); 390 if (~SPI_BFEXT(PCS, mr) & (1 << chip_select)) { 391 mr = SPI_BFINS(PCS, 0xf, mr); 392 spi_writel(as, MR, mr); 393 } 394 395 dev_dbg(&spi->dev, "DEactivate NPCS, mr %08x\n", mr); 396 397 if (!spi_get_csgpiod(spi, 0)) 398 spi_writel(as, CR, SPI_BIT(LASTXFER)); 399 } 400 401 static void atmel_spi_lock(struct atmel_spi *as) __acquires(&as->lock) 402 { 403 spin_lock_irqsave(&as->lock, as->flags); 404 } 405 406 static void atmel_spi_unlock(struct atmel_spi *as) __releases(&as->lock) 407 { 408 spin_unlock_irqrestore(&as->lock, as->flags); 409 } 410 411 static inline bool atmel_spi_is_vmalloc_xfer(struct spi_transfer *xfer) 412 { 413 return is_vmalloc_addr(xfer->tx_buf) || is_vmalloc_addr(xfer->rx_buf); 414 } 415 416 static inline bool atmel_spi_use_dma(struct atmel_spi *as, 417 struct spi_transfer *xfer) 418 { 419 return as->use_dma && xfer->len >= DMA_MIN_BYTES; 420 } 421 422 static bool atmel_spi_can_dma(struct spi_controller *host, 423 struct spi_device *spi, 424 struct spi_transfer *xfer) 425 { 426 struct atmel_spi *as = spi_controller_get_devdata(host); 427 428 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) 429 return atmel_spi_use_dma(as, xfer) && 430 !atmel_spi_is_vmalloc_xfer(xfer); 431 else 432 return atmel_spi_use_dma(as, xfer); 433 434 } 435 436 static int atmel_spi_dma_slave_config(struct atmel_spi *as, u8 bits_per_word) 437 { 438 struct spi_controller *host = platform_get_drvdata(as->pdev); 439 struct dma_slave_config slave_config; 440 int err = 0; 441 442 if (bits_per_word > 8) { 443 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; 444 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; 445 } else { 446 slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 447 slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; 448 } 449 450 slave_config.dst_addr = (dma_addr_t)as->phybase + SPI_TDR; 451 slave_config.src_addr = (dma_addr_t)as->phybase + SPI_RDR; 452 slave_config.src_maxburst = 1; 453 slave_config.dst_maxburst = 1; 454 slave_config.device_fc = false; 455 456 /* 457 * This driver uses fixed peripheral select mode (PS bit set to '0' in 458 * the Mode Register). 459 * So according to the datasheet, when FIFOs are available (and 460 * enabled), the Transmit FIFO operates in Multiple Data Mode. 461 * In this mode, up to 2 data, not 4, can be written into the Transmit 462 * Data Register in a single access. 463 * However, the first data has to be written into the lowest 16 bits and 464 * the second data into the highest 16 bits of the Transmit 465 * Data Register. For 8bit data (the most frequent case), it would 466 * require to rework tx_buf so each data would actually fit 16 bits. 467 * So we'd rather write only one data at the time. Hence the transmit 468 * path works the same whether FIFOs are available (and enabled) or not. 469 */ 470 if (dmaengine_slave_config(host->dma_tx, &slave_config)) { 471 dev_err(&as->pdev->dev, 472 "failed to configure tx dma channel\n"); 473 err = -EINVAL; 474 } 475 476 /* 477 * This driver configures the spi controller for host mode (MSTR bit 478 * set to '1' in the Mode Register). 479 * So according to the datasheet, when FIFOs are available (and 480 * enabled), the Receive FIFO operates in Single Data Mode. 481 * So the receive path works the same whether FIFOs are available (and 482 * enabled) or not. 483 */ 484 if (dmaengine_slave_config(host->dma_rx, &slave_config)) { 485 dev_err(&as->pdev->dev, 486 "failed to configure rx dma channel\n"); 487 err = -EINVAL; 488 } 489 490 return err; 491 } 492 493 static int atmel_spi_configure_dma(struct spi_controller *host, 494 struct atmel_spi *as) 495 { 496 struct device *dev = &as->pdev->dev; 497 int err; 498 499 host->dma_tx = dma_request_chan(dev, "tx"); 500 if (IS_ERR(host->dma_tx)) { 501 err = PTR_ERR(host->dma_tx); 502 dev_dbg(dev, "No TX DMA channel, DMA is disabled\n"); 503 goto error_clear; 504 } 505 506 host->dma_rx = dma_request_chan(dev, "rx"); 507 if (IS_ERR(host->dma_rx)) { 508 err = PTR_ERR(host->dma_rx); 509 /* 510 * No reason to check EPROBE_DEFER here since we have already 511 * requested tx channel. 512 */ 513 dev_dbg(dev, "No RX DMA channel, DMA is disabled\n"); 514 goto error; 515 } 516 517 err = atmel_spi_dma_slave_config(as, 8); 518 if (err) 519 goto error; 520 521 dev_info(&as->pdev->dev, 522 "Using %s (tx) and %s (rx) for DMA transfers\n", 523 dma_chan_name(host->dma_tx), 524 dma_chan_name(host->dma_rx)); 525 526 return 0; 527 error: 528 if (!IS_ERR(host->dma_rx)) 529 dma_release_channel(host->dma_rx); 530 if (!IS_ERR(host->dma_tx)) 531 dma_release_channel(host->dma_tx); 532 error_clear: 533 host->dma_tx = host->dma_rx = NULL; 534 return err; 535 } 536 537 static void atmel_spi_stop_dma(struct spi_controller *host) 538 { 539 if (host->dma_rx) 540 dmaengine_terminate_all(host->dma_rx); 541 if (host->dma_tx) 542 dmaengine_terminate_all(host->dma_tx); 543 } 544 545 static void atmel_spi_release_dma(struct spi_controller *host) 546 { 547 if (host->dma_rx) { 548 dma_release_channel(host->dma_rx); 549 host->dma_rx = NULL; 550 } 551 if (host->dma_tx) { 552 dma_release_channel(host->dma_tx); 553 host->dma_tx = NULL; 554 } 555 } 556 557 /* This function is called by the DMA driver from tasklet context */ 558 static void dma_callback(void *data) 559 { 560 struct spi_controller *host = data; 561 struct atmel_spi *as = spi_controller_get_devdata(host); 562 563 if (is_vmalloc_addr(as->current_transfer->rx_buf) && 564 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { 565 memcpy(as->current_transfer->rx_buf, as->addr_rx_bbuf, 566 as->current_transfer->len); 567 } 568 complete(&as->xfer_completion); 569 } 570 571 /* 572 * Next transfer using PIO without FIFO. 573 */ 574 static void atmel_spi_next_xfer_single(struct spi_controller *host, 575 struct spi_transfer *xfer) 576 { 577 struct atmel_spi *as = spi_controller_get_devdata(host); 578 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; 579 580 dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_pio\n"); 581 582 /* Make sure data is not remaining in RDR */ 583 spi_readl(as, RDR); 584 while (spi_readl(as, SR) & SPI_BIT(RDRF)) { 585 spi_readl(as, RDR); 586 cpu_relax(); 587 } 588 589 if (xfer->bits_per_word > 8) 590 spi_writel(as, TDR, *(u16 *)(xfer->tx_buf + xfer_pos)); 591 else 592 spi_writel(as, TDR, *(u8 *)(xfer->tx_buf + xfer_pos)); 593 594 dev_dbg(host->dev.parent, 595 " start pio xfer %p: len %u tx %p rx %p bitpw %d\n", 596 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, 597 xfer->bits_per_word); 598 599 /* Enable relevant interrupts */ 600 spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES)); 601 } 602 603 /* 604 * Next transfer using PIO with FIFO. 605 */ 606 static void atmel_spi_next_xfer_fifo(struct spi_controller *host, 607 struct spi_transfer *xfer) 608 { 609 struct atmel_spi *as = spi_controller_get_devdata(host); 610 u32 current_remaining_data, num_data; 611 u32 offset = xfer->len - as->current_remaining_bytes; 612 const u16 *words = (const u16 *)((u8 *)xfer->tx_buf + offset); 613 const u8 *bytes = (const u8 *)((u8 *)xfer->tx_buf + offset); 614 u16 td0, td1; 615 u32 fifomr; 616 617 dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_fifo\n"); 618 619 /* Compute the number of data to transfer in the current iteration */ 620 current_remaining_data = ((xfer->bits_per_word > 8) ? 621 ((u32)as->current_remaining_bytes >> 1) : 622 (u32)as->current_remaining_bytes); 623 num_data = min(current_remaining_data, as->fifo_size); 624 625 /* Flush RX and TX FIFOs */ 626 spi_writel(as, CR, SPI_BIT(RXFCLR) | SPI_BIT(TXFCLR)); 627 while (spi_readl(as, FLR)) 628 cpu_relax(); 629 630 /* Set RX FIFO Threshold to the number of data to transfer */ 631 fifomr = spi_readl(as, FMR); 632 spi_writel(as, FMR, SPI_BFINS(RXFTHRES, num_data, fifomr)); 633 634 /* Clear FIFO flags in the Status Register, especially RXFTHF */ 635 (void)spi_readl(as, SR); 636 637 /* Fill TX FIFO */ 638 while (num_data >= 2) { 639 if (xfer->bits_per_word > 8) { 640 td0 = *words++; 641 td1 = *words++; 642 } else { 643 td0 = *bytes++; 644 td1 = *bytes++; 645 } 646 647 spi_writel(as, TDR, (td1 << 16) | td0); 648 num_data -= 2; 649 } 650 651 if (num_data) { 652 if (xfer->bits_per_word > 8) 653 td0 = *words++; 654 else 655 td0 = *bytes++; 656 657 spi_writew(as, TDR, td0); 658 num_data--; 659 } 660 661 dev_dbg(host->dev.parent, 662 " start fifo xfer %p: len %u tx %p rx %p bitpw %d\n", 663 xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, 664 xfer->bits_per_word); 665 666 /* 667 * Enable RX FIFO Threshold Flag interrupt to be notified about 668 * transfer completion. 669 */ 670 spi_writel(as, IER, SPI_BIT(RXFTHF) | SPI_BIT(OVRES)); 671 } 672 673 /* 674 * Next transfer using PIO. 675 */ 676 static void atmel_spi_next_xfer_pio(struct spi_controller *host, 677 struct spi_transfer *xfer) 678 { 679 struct atmel_spi *as = spi_controller_get_devdata(host); 680 681 if (as->fifo_size) 682 atmel_spi_next_xfer_fifo(host, xfer); 683 else 684 atmel_spi_next_xfer_single(host, xfer); 685 } 686 687 /* 688 * Submit next transfer for DMA. 689 */ 690 static int atmel_spi_next_xfer_dma_submit(struct spi_controller *host, 691 struct spi_transfer *xfer, 692 u32 *plen) 693 { 694 struct atmel_spi *as = spi_controller_get_devdata(host); 695 struct dma_chan *rxchan = host->dma_rx; 696 struct dma_chan *txchan = host->dma_tx; 697 struct dma_async_tx_descriptor *rxdesc; 698 struct dma_async_tx_descriptor *txdesc; 699 dma_cookie_t cookie; 700 701 dev_vdbg(host->dev.parent, "atmel_spi_next_xfer_dma_submit\n"); 702 703 /* Check that the channels are available */ 704 if (!rxchan || !txchan) 705 return -ENODEV; 706 707 708 *plen = xfer->len; 709 710 if (atmel_spi_dma_slave_config(as, xfer->bits_per_word)) 711 goto err_exit; 712 713 /* Send both scatterlists */ 714 if (atmel_spi_is_vmalloc_xfer(xfer) && 715 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { 716 rxdesc = dmaengine_prep_slave_single(rxchan, 717 as->dma_addr_rx_bbuf, 718 xfer->len, 719 DMA_DEV_TO_MEM, 720 DMA_PREP_INTERRUPT | 721 DMA_CTRL_ACK); 722 } else { 723 rxdesc = dmaengine_prep_slave_sg(rxchan, 724 xfer->rx_sg.sgl, 725 xfer->rx_sg.nents, 726 DMA_DEV_TO_MEM, 727 DMA_PREP_INTERRUPT | 728 DMA_CTRL_ACK); 729 } 730 if (!rxdesc) 731 goto err_dma; 732 733 if (atmel_spi_is_vmalloc_xfer(xfer) && 734 IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { 735 memcpy(as->addr_tx_bbuf, xfer->tx_buf, xfer->len); 736 txdesc = dmaengine_prep_slave_single(txchan, 737 as->dma_addr_tx_bbuf, 738 xfer->len, DMA_MEM_TO_DEV, 739 DMA_PREP_INTERRUPT | 740 DMA_CTRL_ACK); 741 } else { 742 txdesc = dmaengine_prep_slave_sg(txchan, 743 xfer->tx_sg.sgl, 744 xfer->tx_sg.nents, 745 DMA_MEM_TO_DEV, 746 DMA_PREP_INTERRUPT | 747 DMA_CTRL_ACK); 748 } 749 if (!txdesc) 750 goto err_dma; 751 752 dev_dbg(host->dev.parent, 753 " start dma xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", 754 xfer, xfer->len, xfer->tx_buf, (unsigned long long)xfer->tx_dma, 755 xfer->rx_buf, (unsigned long long)xfer->rx_dma); 756 757 /* Enable relevant interrupts */ 758 spi_writel(as, IER, SPI_BIT(OVRES)); 759 760 /* Put the callback on the RX transfer only, that should finish last */ 761 rxdesc->callback = dma_callback; 762 rxdesc->callback_param = host; 763 764 /* Submit and fire RX and TX with TX last so we're ready to read! */ 765 cookie = rxdesc->tx_submit(rxdesc); 766 if (dma_submit_error(cookie)) 767 goto err_dma; 768 cookie = txdesc->tx_submit(txdesc); 769 if (dma_submit_error(cookie)) 770 goto err_dma; 771 rxchan->device->device_issue_pending(rxchan); 772 txchan->device->device_issue_pending(txchan); 773 774 return 0; 775 776 err_dma: 777 spi_writel(as, IDR, SPI_BIT(OVRES)); 778 atmel_spi_stop_dma(host); 779 err_exit: 780 return -ENOMEM; 781 } 782 783 static void atmel_spi_next_xfer_data(struct spi_controller *host, 784 struct spi_transfer *xfer, 785 dma_addr_t *tx_dma, 786 dma_addr_t *rx_dma, 787 u32 *plen) 788 { 789 *rx_dma = xfer->rx_dma + xfer->len - *plen; 790 *tx_dma = xfer->tx_dma + xfer->len - *plen; 791 if (*plen > host->max_dma_len) 792 *plen = host->max_dma_len; 793 } 794 795 static int atmel_spi_set_xfer_speed(struct atmel_spi *as, 796 struct spi_device *spi, 797 struct spi_transfer *xfer) 798 { 799 u32 scbr, csr; 800 unsigned long bus_hz; 801 int chip_select; 802 803 if (spi_get_csgpiod(spi, 0)) 804 chip_select = as->native_cs_for_gpio; 805 else 806 chip_select = spi_get_chipselect(spi, 0); 807 808 /* v1 chips start out at half the peripheral bus speed. */ 809 bus_hz = as->spi_clk; 810 if (!atmel_spi_is_v2(as)) 811 bus_hz /= 2; 812 813 /* 814 * Calculate the lowest divider that satisfies the 815 * constraint, assuming div32/fdiv/mbz == 0. 816 */ 817 scbr = DIV_ROUND_UP(bus_hz, xfer->speed_hz); 818 819 /* 820 * If the resulting divider doesn't fit into the 821 * register bitfield, we can't satisfy the constraint. 822 */ 823 if (scbr >= (1 << SPI_SCBR_SIZE)) { 824 dev_err(&spi->dev, 825 "setup: %d Hz too slow, scbr %u; min %ld Hz\n", 826 xfer->speed_hz, scbr, bus_hz/255); 827 return -EINVAL; 828 } 829 if (scbr == 0) { 830 dev_err(&spi->dev, 831 "setup: %d Hz too high, scbr %u; max %ld Hz\n", 832 xfer->speed_hz, scbr, bus_hz); 833 return -EINVAL; 834 } 835 csr = spi_readl(as, CSR0 + 4 * chip_select); 836 csr = SPI_BFINS(SCBR, scbr, csr); 837 spi_writel(as, CSR0 + 4 * chip_select, csr); 838 xfer->effective_speed_hz = bus_hz / scbr; 839 840 return 0; 841 } 842 843 /* 844 * Submit next transfer for PDC. 845 * lock is held, spi irq is blocked 846 */ 847 static void atmel_spi_pdc_next_xfer(struct spi_controller *host, 848 struct spi_transfer *xfer) 849 { 850 struct atmel_spi *as = spi_controller_get_devdata(host); 851 u32 len; 852 dma_addr_t tx_dma, rx_dma; 853 854 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); 855 856 len = as->current_remaining_bytes; 857 atmel_spi_next_xfer_data(host, xfer, &tx_dma, &rx_dma, &len); 858 as->current_remaining_bytes -= len; 859 860 spi_writel(as, RPR, rx_dma); 861 spi_writel(as, TPR, tx_dma); 862 863 if (xfer->bits_per_word > 8) 864 len >>= 1; 865 spi_writel(as, RCR, len); 866 spi_writel(as, TCR, len); 867 868 dev_dbg(&host->dev, 869 " start xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", 870 xfer, xfer->len, xfer->tx_buf, 871 (unsigned long long)xfer->tx_dma, xfer->rx_buf, 872 (unsigned long long)xfer->rx_dma); 873 874 if (as->current_remaining_bytes) { 875 len = as->current_remaining_bytes; 876 atmel_spi_next_xfer_data(host, xfer, &tx_dma, &rx_dma, &len); 877 as->current_remaining_bytes -= len; 878 879 spi_writel(as, RNPR, rx_dma); 880 spi_writel(as, TNPR, tx_dma); 881 882 if (xfer->bits_per_word > 8) 883 len >>= 1; 884 spi_writel(as, RNCR, len); 885 spi_writel(as, TNCR, len); 886 887 dev_dbg(&host->dev, 888 " next xfer %p: len %u tx %p/%08llx rx %p/%08llx\n", 889 xfer, xfer->len, xfer->tx_buf, 890 (unsigned long long)xfer->tx_dma, xfer->rx_buf, 891 (unsigned long long)xfer->rx_dma); 892 } 893 894 /* REVISIT: We're waiting for RXBUFF before we start the next 895 * transfer because we need to handle some difficult timing 896 * issues otherwise. If we wait for TXBUFE in one transfer and 897 * then starts waiting for RXBUFF in the next, it's difficult 898 * to tell the difference between the RXBUFF interrupt we're 899 * actually waiting for and the RXBUFF interrupt of the 900 * previous transfer. 901 * 902 * It should be doable, though. Just not now... 903 */ 904 spi_writel(as, IER, SPI_BIT(RXBUFF) | SPI_BIT(OVRES)); 905 spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); 906 } 907 908 /* 909 * For DMA, tx_buf/tx_dma have the same relationship as rx_buf/rx_dma: 910 * - The buffer is either valid for CPU access, else NULL 911 * - If the buffer is valid, so is its DMA address 912 * 913 * This driver manages the dma address unless message->is_dma_mapped. 914 */ 915 static int 916 atmel_spi_dma_map_xfer(struct atmel_spi *as, struct spi_transfer *xfer) 917 { 918 struct device *dev = &as->pdev->dev; 919 920 xfer->tx_dma = xfer->rx_dma = INVALID_DMA_ADDRESS; 921 if (xfer->tx_buf) { 922 /* tx_buf is a const void* where we need a void * for the dma 923 * mapping */ 924 void *nonconst_tx = (void *)xfer->tx_buf; 925 926 xfer->tx_dma = dma_map_single(dev, 927 nonconst_tx, xfer->len, 928 DMA_TO_DEVICE); 929 if (dma_mapping_error(dev, xfer->tx_dma)) 930 return -ENOMEM; 931 } 932 if (xfer->rx_buf) { 933 xfer->rx_dma = dma_map_single(dev, 934 xfer->rx_buf, xfer->len, 935 DMA_FROM_DEVICE); 936 if (dma_mapping_error(dev, xfer->rx_dma)) { 937 if (xfer->tx_buf) 938 dma_unmap_single(dev, 939 xfer->tx_dma, xfer->len, 940 DMA_TO_DEVICE); 941 return -ENOMEM; 942 } 943 } 944 return 0; 945 } 946 947 static void atmel_spi_dma_unmap_xfer(struct spi_controller *host, 948 struct spi_transfer *xfer) 949 { 950 if (xfer->tx_dma != INVALID_DMA_ADDRESS) 951 dma_unmap_single(host->dev.parent, xfer->tx_dma, 952 xfer->len, DMA_TO_DEVICE); 953 if (xfer->rx_dma != INVALID_DMA_ADDRESS) 954 dma_unmap_single(host->dev.parent, xfer->rx_dma, 955 xfer->len, DMA_FROM_DEVICE); 956 } 957 958 static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as) 959 { 960 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); 961 } 962 963 static void 964 atmel_spi_pump_single_data(struct atmel_spi *as, struct spi_transfer *xfer) 965 { 966 u8 *rxp; 967 u16 *rxp16; 968 unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; 969 970 if (xfer->bits_per_word > 8) { 971 rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); 972 *rxp16 = spi_readl(as, RDR); 973 } else { 974 rxp = ((u8 *)xfer->rx_buf) + xfer_pos; 975 *rxp = spi_readl(as, RDR); 976 } 977 if (xfer->bits_per_word > 8) { 978 if (as->current_remaining_bytes > 2) 979 as->current_remaining_bytes -= 2; 980 else 981 as->current_remaining_bytes = 0; 982 } else { 983 as->current_remaining_bytes--; 984 } 985 } 986 987 static void 988 atmel_spi_pump_fifo_data(struct atmel_spi *as, struct spi_transfer *xfer) 989 { 990 u32 fifolr = spi_readl(as, FLR); 991 u32 num_bytes, num_data = SPI_BFEXT(RXFL, fifolr); 992 u32 offset = xfer->len - as->current_remaining_bytes; 993 u16 *words = (u16 *)((u8 *)xfer->rx_buf + offset); 994 u8 *bytes = (u8 *)((u8 *)xfer->rx_buf + offset); 995 u16 rd; /* RD field is the lowest 16 bits of RDR */ 996 997 /* Update the number of remaining bytes to transfer */ 998 num_bytes = ((xfer->bits_per_word > 8) ? 999 (num_data << 1) : 1000 num_data); 1001 1002 if (as->current_remaining_bytes > num_bytes) 1003 as->current_remaining_bytes -= num_bytes; 1004 else 1005 as->current_remaining_bytes = 0; 1006 1007 /* Handle odd number of bytes when data are more than 8bit width */ 1008 if (xfer->bits_per_word > 8) 1009 as->current_remaining_bytes &= ~0x1; 1010 1011 /* Read data */ 1012 while (num_data) { 1013 rd = spi_readl(as, RDR); 1014 if (xfer->bits_per_word > 8) 1015 *words++ = rd; 1016 else 1017 *bytes++ = rd; 1018 num_data--; 1019 } 1020 } 1021 1022 /* Called from IRQ 1023 * 1024 * Must update "current_remaining_bytes" to keep track of data 1025 * to transfer. 1026 */ 1027 static void 1028 atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer) 1029 { 1030 if (as->fifo_size) 1031 atmel_spi_pump_fifo_data(as, xfer); 1032 else 1033 atmel_spi_pump_single_data(as, xfer); 1034 } 1035 1036 /* Interrupt 1037 * 1038 */ 1039 static irqreturn_t 1040 atmel_spi_pio_interrupt(int irq, void *dev_id) 1041 { 1042 struct spi_controller *host = dev_id; 1043 struct atmel_spi *as = spi_controller_get_devdata(host); 1044 u32 status, pending, imr; 1045 struct spi_transfer *xfer; 1046 int ret = IRQ_NONE; 1047 1048 imr = spi_readl(as, IMR); 1049 status = spi_readl(as, SR); 1050 pending = status & imr; 1051 1052 if (pending & SPI_BIT(OVRES)) { 1053 ret = IRQ_HANDLED; 1054 spi_writel(as, IDR, SPI_BIT(OVRES)); 1055 dev_warn(host->dev.parent, "overrun\n"); 1056 1057 /* 1058 * When we get an overrun, we disregard the current 1059 * transfer. Data will not be copied back from any 1060 * bounce buffer and msg->actual_len will not be 1061 * updated with the last xfer. 1062 * 1063 * We will also not process any remaning transfers in 1064 * the message. 1065 */ 1066 as->done_status = -EIO; 1067 smp_wmb(); 1068 1069 /* Clear any overrun happening while cleaning up */ 1070 spi_readl(as, SR); 1071 1072 complete(&as->xfer_completion); 1073 1074 } else if (pending & (SPI_BIT(RDRF) | SPI_BIT(RXFTHF))) { 1075 atmel_spi_lock(as); 1076 1077 if (as->current_remaining_bytes) { 1078 ret = IRQ_HANDLED; 1079 xfer = as->current_transfer; 1080 atmel_spi_pump_pio_data(as, xfer); 1081 if (!as->current_remaining_bytes) 1082 spi_writel(as, IDR, pending); 1083 1084 complete(&as->xfer_completion); 1085 } 1086 1087 atmel_spi_unlock(as); 1088 } else { 1089 WARN_ONCE(pending, "IRQ not handled, pending = %x\n", pending); 1090 ret = IRQ_HANDLED; 1091 spi_writel(as, IDR, pending); 1092 } 1093 1094 return ret; 1095 } 1096 1097 static irqreturn_t 1098 atmel_spi_pdc_interrupt(int irq, void *dev_id) 1099 { 1100 struct spi_controller *host = dev_id; 1101 struct atmel_spi *as = spi_controller_get_devdata(host); 1102 u32 status, pending, imr; 1103 int ret = IRQ_NONE; 1104 1105 imr = spi_readl(as, IMR); 1106 status = spi_readl(as, SR); 1107 pending = status & imr; 1108 1109 if (pending & SPI_BIT(OVRES)) { 1110 1111 ret = IRQ_HANDLED; 1112 1113 spi_writel(as, IDR, (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX) 1114 | SPI_BIT(OVRES))); 1115 1116 /* Clear any overrun happening while cleaning up */ 1117 spi_readl(as, SR); 1118 1119 as->done_status = -EIO; 1120 1121 complete(&as->xfer_completion); 1122 1123 } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) { 1124 ret = IRQ_HANDLED; 1125 1126 spi_writel(as, IDR, pending); 1127 1128 complete(&as->xfer_completion); 1129 } 1130 1131 return ret; 1132 } 1133 1134 static int atmel_word_delay_csr(struct spi_device *spi, struct atmel_spi *as) 1135 { 1136 struct spi_delay *delay = &spi->word_delay; 1137 u32 value = delay->value; 1138 1139 switch (delay->unit) { 1140 case SPI_DELAY_UNIT_NSECS: 1141 value /= 1000; 1142 break; 1143 case SPI_DELAY_UNIT_USECS: 1144 break; 1145 default: 1146 return -EINVAL; 1147 } 1148 1149 return (as->spi_clk / 1000000 * value) >> 5; 1150 } 1151 1152 static void initialize_native_cs_for_gpio(struct atmel_spi *as) 1153 { 1154 int i; 1155 struct spi_controller *host = platform_get_drvdata(as->pdev); 1156 1157 if (!as->native_cs_free) 1158 return; /* already initialized */ 1159 1160 if (!host->cs_gpiods) 1161 return; /* No CS GPIO */ 1162 1163 /* 1164 * On the first version of the controller (AT91RM9200), CS0 1165 * can't be used associated with GPIO 1166 */ 1167 if (atmel_spi_is_v2(as)) 1168 i = 0; 1169 else 1170 i = 1; 1171 1172 for (; i < 4; i++) 1173 if (host->cs_gpiods[i]) 1174 as->native_cs_free |= BIT(i); 1175 1176 if (as->native_cs_free) 1177 as->native_cs_for_gpio = ffs(as->native_cs_free); 1178 } 1179 1180 static int atmel_spi_setup(struct spi_device *spi) 1181 { 1182 struct atmel_spi *as; 1183 struct atmel_spi_device *asd; 1184 u32 csr; 1185 unsigned int bits = spi->bits_per_word; 1186 int chip_select; 1187 int word_delay_csr; 1188 1189 as = spi_controller_get_devdata(spi->controller); 1190 1191 /* see notes above re chipselect */ 1192 if (!spi_get_csgpiod(spi, 0) && (spi->mode & SPI_CS_HIGH)) { 1193 dev_warn(&spi->dev, "setup: non GPIO CS can't be active-high\n"); 1194 return -EINVAL; 1195 } 1196 1197 /* Setup() is called during spi_register_controller(aka 1198 * spi_register_master) but after all membmers of the cs_gpiod 1199 * array have been filled, so we can looked for which native 1200 * CS will be free for using with GPIO 1201 */ 1202 initialize_native_cs_for_gpio(as); 1203 1204 if (spi_get_csgpiod(spi, 0) && as->native_cs_free) { 1205 dev_err(&spi->dev, 1206 "No native CS available to support this GPIO CS\n"); 1207 return -EBUSY; 1208 } 1209 1210 if (spi_get_csgpiod(spi, 0)) 1211 chip_select = as->native_cs_for_gpio; 1212 else 1213 chip_select = spi_get_chipselect(spi, 0); 1214 1215 csr = SPI_BF(BITS, bits - 8); 1216 if (spi->mode & SPI_CPOL) 1217 csr |= SPI_BIT(CPOL); 1218 if (!(spi->mode & SPI_CPHA)) 1219 csr |= SPI_BIT(NCPHA); 1220 1221 if (!spi_get_csgpiod(spi, 0)) 1222 csr |= SPI_BIT(CSAAT); 1223 csr |= SPI_BF(DLYBS, 0); 1224 1225 word_delay_csr = atmel_word_delay_csr(spi, as); 1226 if (word_delay_csr < 0) 1227 return word_delay_csr; 1228 1229 /* DLYBCT adds delays between words. This is useful for slow devices 1230 * that need a bit of time to setup the next transfer. 1231 */ 1232 csr |= SPI_BF(DLYBCT, word_delay_csr); 1233 1234 asd = spi->controller_state; 1235 if (!asd) { 1236 asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); 1237 if (!asd) 1238 return -ENOMEM; 1239 1240 spi->controller_state = asd; 1241 } 1242 1243 asd->csr = csr; 1244 1245 dev_dbg(&spi->dev, 1246 "setup: bpw %u mode 0x%x -> csr%d %08x\n", 1247 bits, spi->mode, spi_get_chipselect(spi, 0), csr); 1248 1249 if (!atmel_spi_is_v2(as)) 1250 spi_writel(as, CSR0 + 4 * chip_select, csr); 1251 1252 return 0; 1253 } 1254 1255 static void atmel_spi_set_cs(struct spi_device *spi, bool enable) 1256 { 1257 struct atmel_spi *as = spi_controller_get_devdata(spi->controller); 1258 /* the core doesn't really pass us enable/disable, but CS HIGH vs CS LOW 1259 * since we already have routines for activate/deactivate translate 1260 * high/low to active/inactive 1261 */ 1262 enable = (!!(spi->mode & SPI_CS_HIGH) == enable); 1263 1264 if (enable) { 1265 cs_activate(as, spi); 1266 } else { 1267 cs_deactivate(as, spi); 1268 } 1269 1270 } 1271 1272 static int atmel_spi_one_transfer(struct spi_controller *host, 1273 struct spi_device *spi, 1274 struct spi_transfer *xfer) 1275 { 1276 struct atmel_spi *as; 1277 u8 bits; 1278 u32 len; 1279 struct atmel_spi_device *asd; 1280 int timeout; 1281 int ret; 1282 unsigned long dma_timeout; 1283 1284 as = spi_controller_get_devdata(host); 1285 1286 asd = spi->controller_state; 1287 bits = (asd->csr >> 4) & 0xf; 1288 if (bits != xfer->bits_per_word - 8) { 1289 dev_dbg(&spi->dev, 1290 "you can't yet change bits_per_word in transfers\n"); 1291 return -ENOPROTOOPT; 1292 } 1293 1294 /* 1295 * DMA map early, for performance (empties dcache ASAP) and 1296 * better fault reporting. 1297 */ 1298 if ((!host->cur_msg->is_dma_mapped) 1299 && as->use_pdc) { 1300 if (atmel_spi_dma_map_xfer(as, xfer) < 0) 1301 return -ENOMEM; 1302 } 1303 1304 atmel_spi_set_xfer_speed(as, spi, xfer); 1305 1306 as->done_status = 0; 1307 as->current_transfer = xfer; 1308 as->current_remaining_bytes = xfer->len; 1309 while (as->current_remaining_bytes) { 1310 reinit_completion(&as->xfer_completion); 1311 1312 if (as->use_pdc) { 1313 atmel_spi_lock(as); 1314 atmel_spi_pdc_next_xfer(host, xfer); 1315 atmel_spi_unlock(as); 1316 } else if (atmel_spi_use_dma(as, xfer)) { 1317 len = as->current_remaining_bytes; 1318 ret = atmel_spi_next_xfer_dma_submit(host, 1319 xfer, &len); 1320 if (ret) { 1321 dev_err(&spi->dev, 1322 "unable to use DMA, fallback to PIO\n"); 1323 as->done_status = ret; 1324 break; 1325 } else { 1326 as->current_remaining_bytes -= len; 1327 if (as->current_remaining_bytes < 0) 1328 as->current_remaining_bytes = 0; 1329 } 1330 } else { 1331 atmel_spi_lock(as); 1332 atmel_spi_next_xfer_pio(host, xfer); 1333 atmel_spi_unlock(as); 1334 } 1335 1336 dma_timeout = wait_for_completion_timeout(&as->xfer_completion, 1337 SPI_DMA_TIMEOUT); 1338 if (WARN_ON(dma_timeout == 0)) { 1339 dev_err(&spi->dev, "spi transfer timeout\n"); 1340 as->done_status = -EIO; 1341 } 1342 1343 if (as->done_status) 1344 break; 1345 } 1346 1347 if (as->done_status) { 1348 if (as->use_pdc) { 1349 dev_warn(host->dev.parent, 1350 "overrun (%u/%u remaining)\n", 1351 spi_readl(as, TCR), spi_readl(as, RCR)); 1352 1353 /* 1354 * Clean up DMA registers and make sure the data 1355 * registers are empty. 1356 */ 1357 spi_writel(as, RNCR, 0); 1358 spi_writel(as, TNCR, 0); 1359 spi_writel(as, RCR, 0); 1360 spi_writel(as, TCR, 0); 1361 for (timeout = 1000; timeout; timeout--) 1362 if (spi_readl(as, SR) & SPI_BIT(TXEMPTY)) 1363 break; 1364 if (!timeout) 1365 dev_warn(host->dev.parent, 1366 "timeout waiting for TXEMPTY"); 1367 while (spi_readl(as, SR) & SPI_BIT(RDRF)) 1368 spi_readl(as, RDR); 1369 1370 /* Clear any overrun happening while cleaning up */ 1371 spi_readl(as, SR); 1372 1373 } else if (atmel_spi_use_dma(as, xfer)) { 1374 atmel_spi_stop_dma(host); 1375 } 1376 } 1377 1378 if (!host->cur_msg->is_dma_mapped 1379 && as->use_pdc) 1380 atmel_spi_dma_unmap_xfer(host, xfer); 1381 1382 if (as->use_pdc) 1383 atmel_spi_disable_pdc_transfer(as); 1384 1385 return as->done_status; 1386 } 1387 1388 static void atmel_spi_cleanup(struct spi_device *spi) 1389 { 1390 struct atmel_spi_device *asd = spi->controller_state; 1391 1392 if (!asd) 1393 return; 1394 1395 spi->controller_state = NULL; 1396 kfree(asd); 1397 } 1398 1399 static inline unsigned int atmel_get_version(struct atmel_spi *as) 1400 { 1401 return spi_readl(as, VERSION) & 0x00000fff; 1402 } 1403 1404 static void atmel_get_caps(struct atmel_spi *as) 1405 { 1406 unsigned int version; 1407 1408 version = atmel_get_version(as); 1409 1410 as->caps.is_spi2 = version > 0x121; 1411 as->caps.has_wdrbt = version >= 0x210; 1412 as->caps.has_dma_support = version >= 0x212; 1413 as->caps.has_pdc_support = version < 0x212; 1414 } 1415 1416 static void atmel_spi_init(struct atmel_spi *as) 1417 { 1418 spi_writel(as, CR, SPI_BIT(SWRST)); 1419 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ 1420 1421 /* It is recommended to enable FIFOs first thing after reset */ 1422 if (as->fifo_size) 1423 spi_writel(as, CR, SPI_BIT(FIFOEN)); 1424 1425 if (as->caps.has_wdrbt) { 1426 spi_writel(as, MR, SPI_BIT(WDRBT) | SPI_BIT(MODFDIS) 1427 | SPI_BIT(MSTR)); 1428 } else { 1429 spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); 1430 } 1431 1432 if (as->use_pdc) 1433 spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); 1434 spi_writel(as, CR, SPI_BIT(SPIEN)); 1435 } 1436 1437 static int atmel_spi_probe(struct platform_device *pdev) 1438 { 1439 struct resource *regs; 1440 int irq; 1441 struct clk *clk; 1442 int ret; 1443 struct spi_controller *host; 1444 struct atmel_spi *as; 1445 1446 /* Select default pin state */ 1447 pinctrl_pm_select_default_state(&pdev->dev); 1448 1449 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1450 if (!regs) 1451 return -ENXIO; 1452 1453 irq = platform_get_irq(pdev, 0); 1454 if (irq < 0) 1455 return irq; 1456 1457 clk = devm_clk_get(&pdev->dev, "spi_clk"); 1458 if (IS_ERR(clk)) 1459 return PTR_ERR(clk); 1460 1461 /* setup spi core then atmel-specific driver state */ 1462 host = spi_alloc_host(&pdev->dev, sizeof(*as)); 1463 if (!host) 1464 return -ENOMEM; 1465 1466 /* the spi->mode bits understood by this driver: */ 1467 host->use_gpio_descriptors = true; 1468 host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; 1469 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 16); 1470 host->dev.of_node = pdev->dev.of_node; 1471 host->bus_num = pdev->id; 1472 host->num_chipselect = 4; 1473 host->setup = atmel_spi_setup; 1474 host->flags = (SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX | 1475 SPI_MASTER_GPIO_SS); 1476 host->transfer_one = atmel_spi_one_transfer; 1477 host->set_cs = atmel_spi_set_cs; 1478 host->cleanup = atmel_spi_cleanup; 1479 host->auto_runtime_pm = true; 1480 host->max_dma_len = SPI_MAX_DMA_XFER; 1481 host->can_dma = atmel_spi_can_dma; 1482 platform_set_drvdata(pdev, host); 1483 1484 as = spi_controller_get_devdata(host); 1485 1486 spin_lock_init(&as->lock); 1487 1488 as->pdev = pdev; 1489 as->regs = devm_ioremap_resource(&pdev->dev, regs); 1490 if (IS_ERR(as->regs)) { 1491 ret = PTR_ERR(as->regs); 1492 goto out_unmap_regs; 1493 } 1494 as->phybase = regs->start; 1495 as->irq = irq; 1496 as->clk = clk; 1497 1498 init_completion(&as->xfer_completion); 1499 1500 atmel_get_caps(as); 1501 1502 as->use_dma = false; 1503 as->use_pdc = false; 1504 if (as->caps.has_dma_support) { 1505 ret = atmel_spi_configure_dma(host, as); 1506 if (ret == 0) { 1507 as->use_dma = true; 1508 } else if (ret == -EPROBE_DEFER) { 1509 goto out_unmap_regs; 1510 } 1511 } else if (as->caps.has_pdc_support) { 1512 as->use_pdc = true; 1513 } 1514 1515 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { 1516 as->addr_rx_bbuf = dma_alloc_coherent(&pdev->dev, 1517 SPI_MAX_DMA_XFER, 1518 &as->dma_addr_rx_bbuf, 1519 GFP_KERNEL | GFP_DMA); 1520 if (!as->addr_rx_bbuf) { 1521 as->use_dma = false; 1522 } else { 1523 as->addr_tx_bbuf = dma_alloc_coherent(&pdev->dev, 1524 SPI_MAX_DMA_XFER, 1525 &as->dma_addr_tx_bbuf, 1526 GFP_KERNEL | GFP_DMA); 1527 if (!as->addr_tx_bbuf) { 1528 as->use_dma = false; 1529 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, 1530 as->addr_rx_bbuf, 1531 as->dma_addr_rx_bbuf); 1532 } 1533 } 1534 if (!as->use_dma) 1535 dev_info(host->dev.parent, 1536 " can not allocate dma coherent memory\n"); 1537 } 1538 1539 if (as->caps.has_dma_support && !as->use_dma) 1540 dev_info(&pdev->dev, "Atmel SPI Controller using PIO only\n"); 1541 1542 if (as->use_pdc) { 1543 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pdc_interrupt, 1544 0, dev_name(&pdev->dev), host); 1545 } else { 1546 ret = devm_request_irq(&pdev->dev, irq, atmel_spi_pio_interrupt, 1547 0, dev_name(&pdev->dev), host); 1548 } 1549 if (ret) 1550 goto out_unmap_regs; 1551 1552 /* Initialize the hardware */ 1553 ret = clk_prepare_enable(clk); 1554 if (ret) 1555 goto out_free_irq; 1556 1557 as->spi_clk = clk_get_rate(clk); 1558 1559 as->fifo_size = 0; 1560 if (!of_property_read_u32(pdev->dev.of_node, "atmel,fifo-size", 1561 &as->fifo_size)) { 1562 dev_info(&pdev->dev, "Using FIFO (%u data)\n", as->fifo_size); 1563 } 1564 1565 atmel_spi_init(as); 1566 1567 pm_runtime_set_autosuspend_delay(&pdev->dev, AUTOSUSPEND_TIMEOUT); 1568 pm_runtime_use_autosuspend(&pdev->dev); 1569 pm_runtime_set_active(&pdev->dev); 1570 pm_runtime_enable(&pdev->dev); 1571 1572 ret = devm_spi_register_controller(&pdev->dev, host); 1573 if (ret) 1574 goto out_free_dma; 1575 1576 /* go! */ 1577 dev_info(&pdev->dev, "Atmel SPI Controller version 0x%x at 0x%08lx (irq %d)\n", 1578 atmel_get_version(as), (unsigned long)regs->start, 1579 irq); 1580 1581 return 0; 1582 1583 out_free_dma: 1584 pm_runtime_disable(&pdev->dev); 1585 pm_runtime_set_suspended(&pdev->dev); 1586 1587 if (as->use_dma) 1588 atmel_spi_release_dma(host); 1589 1590 spi_writel(as, CR, SPI_BIT(SWRST)); 1591 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ 1592 clk_disable_unprepare(clk); 1593 out_free_irq: 1594 out_unmap_regs: 1595 spi_controller_put(host); 1596 return ret; 1597 } 1598 1599 static void atmel_spi_remove(struct platform_device *pdev) 1600 { 1601 struct spi_controller *host = platform_get_drvdata(pdev); 1602 struct atmel_spi *as = spi_controller_get_devdata(host); 1603 1604 pm_runtime_get_sync(&pdev->dev); 1605 1606 /* reset the hardware and block queue progress */ 1607 if (as->use_dma) { 1608 atmel_spi_stop_dma(host); 1609 atmel_spi_release_dma(host); 1610 if (IS_ENABLED(CONFIG_SOC_SAM_V4_V5)) { 1611 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, 1612 as->addr_tx_bbuf, 1613 as->dma_addr_tx_bbuf); 1614 dma_free_coherent(&pdev->dev, SPI_MAX_DMA_XFER, 1615 as->addr_rx_bbuf, 1616 as->dma_addr_rx_bbuf); 1617 } 1618 } 1619 1620 spin_lock_irq(&as->lock); 1621 spi_writel(as, CR, SPI_BIT(SWRST)); 1622 spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ 1623 spi_readl(as, SR); 1624 spin_unlock_irq(&as->lock); 1625 1626 clk_disable_unprepare(as->clk); 1627 1628 pm_runtime_put_noidle(&pdev->dev); 1629 pm_runtime_disable(&pdev->dev); 1630 } 1631 1632 static int atmel_spi_runtime_suspend(struct device *dev) 1633 { 1634 struct spi_controller *host = dev_get_drvdata(dev); 1635 struct atmel_spi *as = spi_controller_get_devdata(host); 1636 1637 clk_disable_unprepare(as->clk); 1638 pinctrl_pm_select_sleep_state(dev); 1639 1640 return 0; 1641 } 1642 1643 static int atmel_spi_runtime_resume(struct device *dev) 1644 { 1645 struct spi_controller *host = dev_get_drvdata(dev); 1646 struct atmel_spi *as = spi_controller_get_devdata(host); 1647 1648 pinctrl_pm_select_default_state(dev); 1649 1650 return clk_prepare_enable(as->clk); 1651 } 1652 1653 static int atmel_spi_suspend(struct device *dev) 1654 { 1655 struct spi_controller *host = dev_get_drvdata(dev); 1656 int ret; 1657 1658 /* Stop the queue running */ 1659 ret = spi_controller_suspend(host); 1660 if (ret) 1661 return ret; 1662 1663 if (!pm_runtime_suspended(dev)) 1664 atmel_spi_runtime_suspend(dev); 1665 1666 return 0; 1667 } 1668 1669 static int atmel_spi_resume(struct device *dev) 1670 { 1671 struct spi_controller *host = dev_get_drvdata(dev); 1672 struct atmel_spi *as = spi_controller_get_devdata(host); 1673 int ret; 1674 1675 ret = clk_prepare_enable(as->clk); 1676 if (ret) 1677 return ret; 1678 1679 atmel_spi_init(as); 1680 1681 clk_disable_unprepare(as->clk); 1682 1683 if (!pm_runtime_suspended(dev)) { 1684 ret = atmel_spi_runtime_resume(dev); 1685 if (ret) 1686 return ret; 1687 } 1688 1689 /* Start the queue running */ 1690 return spi_controller_resume(host); 1691 } 1692 1693 static const struct dev_pm_ops atmel_spi_pm_ops = { 1694 SYSTEM_SLEEP_PM_OPS(atmel_spi_suspend, atmel_spi_resume) 1695 RUNTIME_PM_OPS(atmel_spi_runtime_suspend, 1696 atmel_spi_runtime_resume, NULL) 1697 }; 1698 1699 static const struct of_device_id atmel_spi_dt_ids[] = { 1700 { .compatible = "atmel,at91rm9200-spi" }, 1701 { /* sentinel */ } 1702 }; 1703 1704 MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids); 1705 1706 static struct platform_driver atmel_spi_driver = { 1707 .driver = { 1708 .name = "atmel_spi", 1709 .pm = pm_ptr(&atmel_spi_pm_ops), 1710 .of_match_table = atmel_spi_dt_ids, 1711 }, 1712 .probe = atmel_spi_probe, 1713 .remove_new = atmel_spi_remove, 1714 }; 1715 module_platform_driver(atmel_spi_driver); 1716 1717 MODULE_DESCRIPTION("Atmel AT32/AT91 SPI Controller driver"); 1718 MODULE_AUTHOR("Haavard Skinnemoen (Atmel)"); 1719 MODULE_LICENSE("GPL"); 1720 MODULE_ALIAS("platform:atmel_spi"); 1721