1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (C) 2009 Texas Instruments. 4 * Copyright (C) 2010 EF Johnson Technologies 5 */ 6 7 #include <linux/interrupt.h> 8 #include <linux/io.h> 9 #include <linux/gpio/consumer.h> 10 #include <linux/module.h> 11 #include <linux/delay.h> 12 #include <linux/platform_device.h> 13 #include <linux/err.h> 14 #include <linux/clk.h> 15 #include <linux/dmaengine.h> 16 #include <linux/dma-mapping.h> 17 #include <linux/of.h> 18 #include <linux/spi/spi.h> 19 #include <linux/spi/spi_bitbang.h> 20 #include <linux/slab.h> 21 22 #include <linux/platform_data/spi-davinci.h> 23 24 #define CS_DEFAULT 0xFF 25 26 #define SPIFMT_PHASE_MASK BIT(16) 27 #define SPIFMT_POLARITY_MASK BIT(17) 28 #define SPIFMT_DISTIMER_MASK BIT(18) 29 #define SPIFMT_SHIFTDIR_MASK BIT(20) 30 #define SPIFMT_WAITENA_MASK BIT(21) 31 #define SPIFMT_PARITYENA_MASK BIT(22) 32 #define SPIFMT_ODD_PARITY_MASK BIT(23) 33 #define SPIFMT_WDELAY_MASK 0x3f000000u 34 #define SPIFMT_WDELAY_SHIFT 24 35 #define SPIFMT_PRESCALE_SHIFT 8 36 37 /* SPIPC0 */ 38 #define SPIPC0_DIFUN_MASK BIT(11) /* MISO */ 39 #define SPIPC0_DOFUN_MASK BIT(10) /* MOSI */ 40 #define SPIPC0_CLKFUN_MASK BIT(9) /* CLK */ 41 #define SPIPC0_SPIENA_MASK BIT(8) /* nREADY */ 42 43 #define SPIINT_MASKALL 0x0101035F 44 #define SPIINT_MASKINT 0x0000015F 45 #define SPI_INTLVL_1 0x000001FF 46 #define SPI_INTLVL_0 0x00000000 47 48 /* SPIDAT1 (upper 16 bit defines) */ 49 #define SPIDAT1_CSHOLD_MASK BIT(12) 50 #define SPIDAT1_WDEL BIT(10) 51 52 /* SPIGCR1 */ 53 #define SPIGCR1_CLKMOD_MASK BIT(1) 54 #define SPIGCR1_MASTER_MASK BIT(0) 55 #define SPIGCR1_POWERDOWN_MASK BIT(8) 56 #define SPIGCR1_LOOPBACK_MASK BIT(16) 57 #define SPIGCR1_SPIENA_MASK BIT(24) 58 59 /* SPIBUF */ 60 #define SPIBUF_TXFULL_MASK BIT(29) 61 #define SPIBUF_RXEMPTY_MASK BIT(31) 62 63 /* SPIDELAY */ 64 #define SPIDELAY_C2TDELAY_SHIFT 24 65 #define SPIDELAY_C2TDELAY_MASK (0xFF << SPIDELAY_C2TDELAY_SHIFT) 66 #define SPIDELAY_T2CDELAY_SHIFT 16 67 #define SPIDELAY_T2CDELAY_MASK (0xFF << SPIDELAY_T2CDELAY_SHIFT) 68 #define SPIDELAY_T2EDELAY_SHIFT 8 69 #define SPIDELAY_T2EDELAY_MASK (0xFF << SPIDELAY_T2EDELAY_SHIFT) 70 #define SPIDELAY_C2EDELAY_SHIFT 0 71 #define SPIDELAY_C2EDELAY_MASK 0xFF 72 73 /* Error Masks */ 74 #define SPIFLG_DLEN_ERR_MASK BIT(0) 75 #define SPIFLG_TIMEOUT_MASK BIT(1) 76 #define SPIFLG_PARERR_MASK BIT(2) 77 #define SPIFLG_DESYNC_MASK BIT(3) 78 #define SPIFLG_BITERR_MASK BIT(4) 79 #define SPIFLG_OVRRUN_MASK BIT(6) 80 #define SPIFLG_BUF_INIT_ACTIVE_MASK BIT(24) 81 #define SPIFLG_ERROR_MASK (SPIFLG_DLEN_ERR_MASK \ 82 | SPIFLG_TIMEOUT_MASK | SPIFLG_PARERR_MASK \ 83 | SPIFLG_DESYNC_MASK | SPIFLG_BITERR_MASK \ 84 | SPIFLG_OVRRUN_MASK) 85 86 #define SPIINT_DMA_REQ_EN BIT(16) 87 88 /* SPI Controller registers */ 89 #define SPIGCR0 0x00 90 #define SPIGCR1 0x04 91 #define SPIINT 0x08 92 #define SPILVL 0x0c 93 #define SPIFLG 0x10 94 #define SPIPC0 0x14 95 #define SPIDAT1 0x3c 96 #define SPIBUF 0x40 97 #define SPIDELAY 0x48 98 #define SPIDEF 0x4c 99 #define SPIFMT0 0x50 100 101 #define DMA_MIN_BYTES 16 102 103 /* SPI Controller driver's private data. */ 104 struct davinci_spi { 105 struct spi_bitbang bitbang; 106 struct clk *clk; 107 108 u8 version; 109 resource_size_t pbase; 110 void __iomem *base; 111 u32 irq; 112 struct completion done; 113 114 const void *tx; 115 void *rx; 116 int rcount; 117 int wcount; 118 119 struct dma_chan *dma_rx; 120 struct dma_chan *dma_tx; 121 122 struct davinci_spi_platform_data pdata; 123 124 void (*get_rx)(u32 rx_data, struct davinci_spi *); 125 u32 (*get_tx)(struct davinci_spi *); 126 127 u8 *bytes_per_word; 128 129 u8 prescaler_limit; 130 }; 131 132 static struct davinci_spi_config davinci_spi_default_cfg; 133 134 static void davinci_spi_rx_buf_u8(u32 data, struct davinci_spi *dspi) 135 { 136 if (dspi->rx) { 137 u8 *rx = dspi->rx; 138 *rx++ = (u8)data; 139 dspi->rx = rx; 140 } 141 } 142 143 static void davinci_spi_rx_buf_u16(u32 data, struct davinci_spi *dspi) 144 { 145 if (dspi->rx) { 146 u16 *rx = dspi->rx; 147 *rx++ = (u16)data; 148 dspi->rx = rx; 149 } 150 } 151 152 static u32 davinci_spi_tx_buf_u8(struct davinci_spi *dspi) 153 { 154 u32 data = 0; 155 156 if (dspi->tx) { 157 const u8 *tx = dspi->tx; 158 159 data = *tx++; 160 dspi->tx = tx; 161 } 162 return data; 163 } 164 165 static u32 davinci_spi_tx_buf_u16(struct davinci_spi *dspi) 166 { 167 u32 data = 0; 168 169 if (dspi->tx) { 170 const u16 *tx = dspi->tx; 171 172 data = *tx++; 173 dspi->tx = tx; 174 } 175 return data; 176 } 177 178 static inline void set_io_bits(void __iomem *addr, u32 bits) 179 { 180 u32 v = ioread32(addr); 181 182 v |= bits; 183 iowrite32(v, addr); 184 } 185 186 static inline void clear_io_bits(void __iomem *addr, u32 bits) 187 { 188 u32 v = ioread32(addr); 189 190 v &= ~bits; 191 iowrite32(v, addr); 192 } 193 194 /* 195 * Interface to control the chip select signal 196 */ 197 static void davinci_spi_chipselect(struct spi_device *spi, int value) 198 { 199 struct davinci_spi *dspi; 200 struct davinci_spi_config *spicfg = spi->controller_data; 201 u8 chip_sel = spi_get_chipselect(spi, 0); 202 u16 spidat1 = CS_DEFAULT; 203 204 dspi = spi_controller_get_devdata(spi->controller); 205 206 /* program delay transfers if tx_delay is non zero */ 207 if (spicfg && spicfg->wdelay) 208 spidat1 |= SPIDAT1_WDEL; 209 210 /* 211 * Board specific chip select logic decides the polarity and cs 212 * line for the controller 213 */ 214 if (spi_get_csgpiod(spi, 0)) { 215 if (value == BITBANG_CS_ACTIVE) 216 gpiod_set_value(spi_get_csgpiod(spi, 0), 1); 217 else 218 gpiod_set_value(spi_get_csgpiod(spi, 0), 0); 219 } else { 220 if (value == BITBANG_CS_ACTIVE) { 221 if (!(spi->mode & SPI_CS_WORD)) 222 spidat1 |= SPIDAT1_CSHOLD_MASK; 223 spidat1 &= ~(0x1 << chip_sel); 224 } 225 } 226 227 iowrite16(spidat1, dspi->base + SPIDAT1 + 2); 228 } 229 230 /** 231 * davinci_spi_get_prescale - Calculates the correct prescale value 232 * @dspi: the controller data 233 * @max_speed_hz: the maximum rate the SPI clock can run at 234 * 235 * This function calculates the prescale value that generates a clock rate 236 * less than or equal to the specified maximum. 237 * 238 * Returns: calculated prescale value for easy programming into SPI registers 239 * or negative error number if valid prescalar cannot be updated. 240 */ 241 static inline int davinci_spi_get_prescale(struct davinci_spi *dspi, 242 u32 max_speed_hz) 243 { 244 int ret; 245 246 /* Subtract 1 to match what will be programmed into SPI register. */ 247 ret = DIV_ROUND_UP(clk_get_rate(dspi->clk), max_speed_hz) - 1; 248 249 if (ret < dspi->prescaler_limit || ret > 255) 250 return -EINVAL; 251 252 return ret; 253 } 254 255 /** 256 * davinci_spi_setup_transfer - This functions will determine transfer method 257 * @spi: spi device on which data transfer to be done 258 * @t: spi transfer in which transfer info is filled 259 * 260 * This function determines data transfer method (8/16/32 bit transfer). 261 * It will also set the SPI Clock Control register according to 262 * SPI slave device freq. 263 */ 264 static int davinci_spi_setup_transfer(struct spi_device *spi, 265 struct spi_transfer *t) 266 { 267 268 struct davinci_spi *dspi; 269 struct davinci_spi_config *spicfg; 270 u8 bits_per_word = 0; 271 u32 hz = 0, spifmt = 0; 272 int prescale; 273 274 dspi = spi_controller_get_devdata(spi->controller); 275 spicfg = spi->controller_data; 276 if (!spicfg) 277 spicfg = &davinci_spi_default_cfg; 278 279 if (t) { 280 bits_per_word = t->bits_per_word; 281 hz = t->speed_hz; 282 } 283 284 /* if bits_per_word is not set then set it default */ 285 if (!bits_per_word) 286 bits_per_word = spi->bits_per_word; 287 288 /* 289 * Assign function pointer to appropriate transfer method 290 * 8bit, 16bit or 32bit transfer 291 */ 292 if (bits_per_word <= 8) { 293 dspi->get_rx = davinci_spi_rx_buf_u8; 294 dspi->get_tx = davinci_spi_tx_buf_u8; 295 dspi->bytes_per_word[spi_get_chipselect(spi, 0)] = 1; 296 } else { 297 dspi->get_rx = davinci_spi_rx_buf_u16; 298 dspi->get_tx = davinci_spi_tx_buf_u16; 299 dspi->bytes_per_word[spi_get_chipselect(spi, 0)] = 2; 300 } 301 302 if (!hz) 303 hz = spi->max_speed_hz; 304 305 /* Set up SPIFMTn register, unique to this chipselect. */ 306 307 prescale = davinci_spi_get_prescale(dspi, hz); 308 if (prescale < 0) 309 return prescale; 310 311 spifmt = (prescale << SPIFMT_PRESCALE_SHIFT) | (bits_per_word & 0x1f); 312 313 if (spi->mode & SPI_LSB_FIRST) 314 spifmt |= SPIFMT_SHIFTDIR_MASK; 315 316 if (spi->mode & SPI_CPOL) 317 spifmt |= SPIFMT_POLARITY_MASK; 318 319 if (!(spi->mode & SPI_CPHA)) 320 spifmt |= SPIFMT_PHASE_MASK; 321 322 /* 323 * Assume wdelay is used only on SPI peripherals that has this field 324 * in SPIFMTn register and when it's configured from board file or DT. 325 */ 326 if (spicfg->wdelay) 327 spifmt |= ((spicfg->wdelay << SPIFMT_WDELAY_SHIFT) 328 & SPIFMT_WDELAY_MASK); 329 330 /* 331 * Version 1 hardware supports two basic SPI modes: 332 * - Standard SPI mode uses 4 pins, with chipselect 333 * - 3 pin SPI is a 4 pin variant without CS (SPI_NO_CS) 334 * (distinct from SPI_3WIRE, with just one data wire; 335 * or similar variants without MOSI or without MISO) 336 * 337 * Version 2 hardware supports an optional handshaking signal, 338 * so it can support two more modes: 339 * - 5 pin SPI variant is standard SPI plus SPI_READY 340 * - 4 pin with enable is (SPI_READY | SPI_NO_CS) 341 */ 342 343 if (dspi->version == SPI_VERSION_2) { 344 345 u32 delay = 0; 346 347 if (spicfg->odd_parity) 348 spifmt |= SPIFMT_ODD_PARITY_MASK; 349 350 if (spicfg->parity_enable) 351 spifmt |= SPIFMT_PARITYENA_MASK; 352 353 if (spicfg->timer_disable) { 354 spifmt |= SPIFMT_DISTIMER_MASK; 355 } else { 356 delay |= (spicfg->c2tdelay << SPIDELAY_C2TDELAY_SHIFT) 357 & SPIDELAY_C2TDELAY_MASK; 358 delay |= (spicfg->t2cdelay << SPIDELAY_T2CDELAY_SHIFT) 359 & SPIDELAY_T2CDELAY_MASK; 360 } 361 362 if (spi->mode & SPI_READY) { 363 spifmt |= SPIFMT_WAITENA_MASK; 364 delay |= (spicfg->t2edelay << SPIDELAY_T2EDELAY_SHIFT) 365 & SPIDELAY_T2EDELAY_MASK; 366 delay |= (spicfg->c2edelay << SPIDELAY_C2EDELAY_SHIFT) 367 & SPIDELAY_C2EDELAY_MASK; 368 } 369 370 iowrite32(delay, dspi->base + SPIDELAY); 371 } 372 373 iowrite32(spifmt, dspi->base + SPIFMT0); 374 375 return 0; 376 } 377 378 static int davinci_spi_of_setup(struct spi_device *spi) 379 { 380 struct davinci_spi_config *spicfg = spi->controller_data; 381 struct device_node *np = spi->dev.of_node; 382 struct davinci_spi *dspi = spi_controller_get_devdata(spi->controller); 383 u32 prop; 384 385 if (spicfg == NULL && np) { 386 spicfg = kzalloc(sizeof(*spicfg), GFP_KERNEL); 387 if (!spicfg) 388 return -ENOMEM; 389 *spicfg = davinci_spi_default_cfg; 390 /* override with dt configured values */ 391 if (!of_property_read_u32(np, "ti,spi-wdelay", &prop)) 392 spicfg->wdelay = (u8)prop; 393 spi->controller_data = spicfg; 394 395 if (dspi->dma_rx && dspi->dma_tx) 396 spicfg->io_type = SPI_IO_TYPE_DMA; 397 } 398 399 return 0; 400 } 401 402 /** 403 * davinci_spi_setup - This functions will set default transfer method 404 * @spi: spi device on which data transfer to be done 405 * 406 * This functions sets the default transfer method. 407 */ 408 static int davinci_spi_setup(struct spi_device *spi) 409 { 410 struct davinci_spi *dspi; 411 struct device_node *np = spi->dev.of_node; 412 bool internal_cs = true; 413 414 dspi = spi_controller_get_devdata(spi->controller); 415 416 if (!(spi->mode & SPI_NO_CS)) { 417 if (np && spi_get_csgpiod(spi, 0)) 418 internal_cs = false; 419 420 if (internal_cs) 421 set_io_bits(dspi->base + SPIPC0, 1 << spi_get_chipselect(spi, 0)); 422 } 423 424 if (spi->mode & SPI_READY) 425 set_io_bits(dspi->base + SPIPC0, SPIPC0_SPIENA_MASK); 426 427 if (spi->mode & SPI_LOOP) 428 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); 429 else 430 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_LOOPBACK_MASK); 431 432 return davinci_spi_of_setup(spi); 433 } 434 435 static void davinci_spi_cleanup(struct spi_device *spi) 436 { 437 struct davinci_spi_config *spicfg = spi->controller_data; 438 439 spi->controller_data = NULL; 440 if (spi->dev.of_node) 441 kfree(spicfg); 442 } 443 444 static bool davinci_spi_can_dma(struct spi_controller *host, 445 struct spi_device *spi, 446 struct spi_transfer *xfer) 447 { 448 struct davinci_spi_config *spicfg = spi->controller_data; 449 bool can_dma = false; 450 451 if (spicfg) 452 can_dma = (spicfg->io_type == SPI_IO_TYPE_DMA) && 453 (xfer->len >= DMA_MIN_BYTES) && 454 !is_vmalloc_addr(xfer->rx_buf) && 455 !is_vmalloc_addr(xfer->tx_buf); 456 457 return can_dma; 458 } 459 460 static int davinci_spi_check_error(struct davinci_spi *dspi, int int_status) 461 { 462 struct device *sdev = dspi->bitbang.master->dev.parent; 463 464 if (int_status & SPIFLG_TIMEOUT_MASK) { 465 dev_err(sdev, "SPI Time-out Error\n"); 466 return -ETIMEDOUT; 467 } 468 if (int_status & SPIFLG_DESYNC_MASK) { 469 dev_err(sdev, "SPI Desynchronization Error\n"); 470 return -EIO; 471 } 472 if (int_status & SPIFLG_BITERR_MASK) { 473 dev_err(sdev, "SPI Bit error\n"); 474 return -EIO; 475 } 476 477 if (dspi->version == SPI_VERSION_2) { 478 if (int_status & SPIFLG_DLEN_ERR_MASK) { 479 dev_err(sdev, "SPI Data Length Error\n"); 480 return -EIO; 481 } 482 if (int_status & SPIFLG_PARERR_MASK) { 483 dev_err(sdev, "SPI Parity Error\n"); 484 return -EIO; 485 } 486 if (int_status & SPIFLG_OVRRUN_MASK) { 487 dev_err(sdev, "SPI Data Overrun error\n"); 488 return -EIO; 489 } 490 if (int_status & SPIFLG_BUF_INIT_ACTIVE_MASK) { 491 dev_err(sdev, "SPI Buffer Init Active\n"); 492 return -EBUSY; 493 } 494 } 495 496 return 0; 497 } 498 499 /** 500 * davinci_spi_process_events - check for and handle any SPI controller events 501 * @dspi: the controller data 502 * 503 * This function will check the SPIFLG register and handle any events that are 504 * detected there 505 */ 506 static int davinci_spi_process_events(struct davinci_spi *dspi) 507 { 508 u32 buf, status, errors = 0, spidat1; 509 510 buf = ioread32(dspi->base + SPIBUF); 511 512 if (dspi->rcount > 0 && !(buf & SPIBUF_RXEMPTY_MASK)) { 513 dspi->get_rx(buf & 0xFFFF, dspi); 514 dspi->rcount--; 515 } 516 517 status = ioread32(dspi->base + SPIFLG); 518 519 if (unlikely(status & SPIFLG_ERROR_MASK)) { 520 errors = status & SPIFLG_ERROR_MASK; 521 goto out; 522 } 523 524 if (dspi->wcount > 0 && !(buf & SPIBUF_TXFULL_MASK)) { 525 spidat1 = ioread32(dspi->base + SPIDAT1); 526 dspi->wcount--; 527 spidat1 &= ~0xFFFF; 528 spidat1 |= 0xFFFF & dspi->get_tx(dspi); 529 iowrite32(spidat1, dspi->base + SPIDAT1); 530 } 531 532 out: 533 return errors; 534 } 535 536 static void davinci_spi_dma_rx_callback(void *data) 537 { 538 struct davinci_spi *dspi = (struct davinci_spi *)data; 539 540 dspi->rcount = 0; 541 542 if (!dspi->wcount && !dspi->rcount) 543 complete(&dspi->done); 544 } 545 546 static void davinci_spi_dma_tx_callback(void *data) 547 { 548 struct davinci_spi *dspi = (struct davinci_spi *)data; 549 550 dspi->wcount = 0; 551 552 if (!dspi->wcount && !dspi->rcount) 553 complete(&dspi->done); 554 } 555 556 /** 557 * davinci_spi_bufs - functions which will handle transfer data 558 * @spi: spi device on which data transfer to be done 559 * @t: spi transfer in which transfer info is filled 560 * 561 * This function will put data to be transferred into data register 562 * of SPI controller and then wait until the completion will be marked 563 * by the IRQ Handler. 564 */ 565 static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) 566 { 567 struct davinci_spi *dspi; 568 int data_type, ret = -ENOMEM; 569 u32 tx_data, spidat1; 570 u32 errors = 0; 571 struct davinci_spi_config *spicfg; 572 struct davinci_spi_platform_data *pdata; 573 574 dspi = spi_controller_get_devdata(spi->controller); 575 pdata = &dspi->pdata; 576 spicfg = (struct davinci_spi_config *)spi->controller_data; 577 if (!spicfg) 578 spicfg = &davinci_spi_default_cfg; 579 580 /* convert len to words based on bits_per_word */ 581 data_type = dspi->bytes_per_word[spi_get_chipselect(spi, 0)]; 582 583 dspi->tx = t->tx_buf; 584 dspi->rx = t->rx_buf; 585 dspi->wcount = t->len / data_type; 586 dspi->rcount = dspi->wcount; 587 588 spidat1 = ioread32(dspi->base + SPIDAT1); 589 590 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); 591 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); 592 593 reinit_completion(&dspi->done); 594 595 if (!davinci_spi_can_dma(spi->controller, spi, t)) { 596 if (spicfg->io_type != SPI_IO_TYPE_POLL) 597 set_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); 598 /* start the transfer */ 599 dspi->wcount--; 600 tx_data = dspi->get_tx(dspi); 601 spidat1 &= 0xFFFF0000; 602 spidat1 |= tx_data & 0xFFFF; 603 iowrite32(spidat1, dspi->base + SPIDAT1); 604 } else { 605 struct dma_slave_config dma_rx_conf = { 606 .direction = DMA_DEV_TO_MEM, 607 .src_addr = (unsigned long)dspi->pbase + SPIBUF, 608 .src_addr_width = data_type, 609 .src_maxburst = 1, 610 }; 611 struct dma_slave_config dma_tx_conf = { 612 .direction = DMA_MEM_TO_DEV, 613 .dst_addr = (unsigned long)dspi->pbase + SPIDAT1, 614 .dst_addr_width = data_type, 615 .dst_maxburst = 1, 616 }; 617 struct dma_async_tx_descriptor *rxdesc; 618 struct dma_async_tx_descriptor *txdesc; 619 620 dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf); 621 dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf); 622 623 rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx, 624 t->rx_sg.sgl, t->rx_sg.nents, DMA_DEV_TO_MEM, 625 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 626 if (!rxdesc) 627 goto err_desc; 628 629 if (!t->tx_buf) { 630 /* To avoid errors when doing rx-only transfers with 631 * many SG entries (> 20), use the rx buffer as the 632 * dummy tx buffer so that dma reloads are done at the 633 * same time for rx and tx. 634 */ 635 t->tx_sg.sgl = t->rx_sg.sgl; 636 t->tx_sg.nents = t->rx_sg.nents; 637 } 638 639 txdesc = dmaengine_prep_slave_sg(dspi->dma_tx, 640 t->tx_sg.sgl, t->tx_sg.nents, DMA_MEM_TO_DEV, 641 DMA_PREP_INTERRUPT | DMA_CTRL_ACK); 642 if (!txdesc) 643 goto err_desc; 644 645 rxdesc->callback = davinci_spi_dma_rx_callback; 646 rxdesc->callback_param = (void *)dspi; 647 txdesc->callback = davinci_spi_dma_tx_callback; 648 txdesc->callback_param = (void *)dspi; 649 650 if (pdata->cshold_bug) 651 iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2); 652 653 dmaengine_submit(rxdesc); 654 dmaengine_submit(txdesc); 655 656 dma_async_issue_pending(dspi->dma_rx); 657 dma_async_issue_pending(dspi->dma_tx); 658 659 set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); 660 } 661 662 /* Wait for the transfer to complete */ 663 if (spicfg->io_type != SPI_IO_TYPE_POLL) { 664 if (wait_for_completion_timeout(&dspi->done, HZ) == 0) 665 errors = SPIFLG_TIMEOUT_MASK; 666 } else { 667 while (dspi->rcount > 0 || dspi->wcount > 0) { 668 errors = davinci_spi_process_events(dspi); 669 if (errors) 670 break; 671 cpu_relax(); 672 } 673 } 674 675 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL); 676 if (davinci_spi_can_dma(spi->controller, spi, t)) 677 clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN); 678 679 clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK); 680 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); 681 682 /* 683 * Check for bit error, desync error,parity error,timeout error and 684 * receive overflow errors 685 */ 686 if (errors) { 687 ret = davinci_spi_check_error(dspi, errors); 688 WARN(!ret, "%s: error reported but no error found!\n", 689 dev_name(&spi->dev)); 690 return ret; 691 } 692 693 if (dspi->rcount != 0 || dspi->wcount != 0) { 694 dev_err(&spi->dev, "SPI data transfer error\n"); 695 return -EIO; 696 } 697 698 return t->len; 699 700 err_desc: 701 return ret; 702 } 703 704 /** 705 * dummy_thread_fn - dummy thread function 706 * @irq: IRQ number for this SPI Master 707 * @data: structure for SPI Master controller davinci_spi 708 * 709 * This is to satisfy the request_threaded_irq() API so that the irq 710 * handler is called in interrupt context. 711 */ 712 static irqreturn_t dummy_thread_fn(s32 irq, void *data) 713 { 714 return IRQ_HANDLED; 715 } 716 717 /** 718 * davinci_spi_irq - Interrupt handler for SPI Master Controller 719 * @irq: IRQ number for this SPI Master 720 * @data: structure for SPI Master controller davinci_spi 721 * 722 * ISR will determine that interrupt arrives either for READ or WRITE command. 723 * According to command it will do the appropriate action. It will check 724 * transfer length and if it is not zero then dispatch transfer command again. 725 * If transfer length is zero then it will indicate the COMPLETION so that 726 * davinci_spi_bufs function can go ahead. 727 */ 728 static irqreturn_t davinci_spi_irq(s32 irq, void *data) 729 { 730 struct davinci_spi *dspi = data; 731 int status; 732 733 status = davinci_spi_process_events(dspi); 734 if (unlikely(status != 0)) 735 clear_io_bits(dspi->base + SPIINT, SPIINT_MASKINT); 736 737 if ((!dspi->rcount && !dspi->wcount) || status) 738 complete(&dspi->done); 739 740 return IRQ_HANDLED; 741 } 742 743 static int davinci_spi_request_dma(struct davinci_spi *dspi) 744 { 745 struct device *sdev = dspi->bitbang.master->dev.parent; 746 747 dspi->dma_rx = dma_request_chan(sdev, "rx"); 748 if (IS_ERR(dspi->dma_rx)) 749 return PTR_ERR(dspi->dma_rx); 750 751 dspi->dma_tx = dma_request_chan(sdev, "tx"); 752 if (IS_ERR(dspi->dma_tx)) { 753 dma_release_channel(dspi->dma_rx); 754 return PTR_ERR(dspi->dma_tx); 755 } 756 757 return 0; 758 } 759 760 #if defined(CONFIG_OF) 761 762 /* OF SPI data structure */ 763 struct davinci_spi_of_data { 764 u8 version; 765 u8 prescaler_limit; 766 }; 767 768 static const struct davinci_spi_of_data dm6441_spi_data = { 769 .version = SPI_VERSION_1, 770 .prescaler_limit = 2, 771 }; 772 773 static const struct davinci_spi_of_data da830_spi_data = { 774 .version = SPI_VERSION_2, 775 .prescaler_limit = 2, 776 }; 777 778 static const struct davinci_spi_of_data keystone_spi_data = { 779 .version = SPI_VERSION_1, 780 .prescaler_limit = 0, 781 }; 782 783 static const struct of_device_id davinci_spi_of_match[] = { 784 { 785 .compatible = "ti,dm6441-spi", 786 .data = &dm6441_spi_data, 787 }, 788 { 789 .compatible = "ti,da830-spi", 790 .data = &da830_spi_data, 791 }, 792 { 793 .compatible = "ti,keystone-spi", 794 .data = &keystone_spi_data, 795 }, 796 { }, 797 }; 798 MODULE_DEVICE_TABLE(of, davinci_spi_of_match); 799 800 /** 801 * spi_davinci_get_pdata - Get platform data from DTS binding 802 * @pdev: ptr to platform data 803 * @dspi: ptr to driver data 804 * 805 * Parses and populates pdata in dspi from device tree bindings. 806 * 807 * NOTE: Not all platform data params are supported currently. 808 */ 809 static int spi_davinci_get_pdata(struct platform_device *pdev, 810 struct davinci_spi *dspi) 811 { 812 struct device_node *node = pdev->dev.of_node; 813 const struct davinci_spi_of_data *spi_data; 814 struct davinci_spi_platform_data *pdata; 815 unsigned int num_cs, intr_line = 0; 816 817 pdata = &dspi->pdata; 818 819 spi_data = device_get_match_data(&pdev->dev); 820 821 pdata->version = spi_data->version; 822 pdata->prescaler_limit = spi_data->prescaler_limit; 823 /* 824 * default num_cs is 1 and all chipsel are internal to the chip 825 * indicated by chip_sel being NULL or cs_gpios being NULL or 826 * set to -ENOENT. num-cs includes internal as well as gpios. 827 * indicated by chip_sel being NULL. GPIO based CS is not 828 * supported yet in DT bindings. 829 */ 830 num_cs = 1; 831 of_property_read_u32(node, "num-cs", &num_cs); 832 pdata->num_chipselect = num_cs; 833 of_property_read_u32(node, "ti,davinci-spi-intr-line", &intr_line); 834 pdata->intr_line = intr_line; 835 return 0; 836 } 837 #else 838 static int spi_davinci_get_pdata(struct platform_device *pdev, 839 struct davinci_spi *dspi) 840 { 841 return -ENODEV; 842 } 843 #endif 844 845 /** 846 * davinci_spi_probe - probe function for SPI Master Controller 847 * @pdev: platform_device structure which contains plateform specific data 848 * 849 * According to Linux Device Model this function will be invoked by Linux 850 * with platform_device struct which contains the device specific info. 851 * This function will map the SPI controller's memory, register IRQ, 852 * Reset SPI controller and setting its registers to default value. 853 * It will invoke spi_bitbang_start to create work queue so that client driver 854 * can register transfer method to work queue. 855 */ 856 static int davinci_spi_probe(struct platform_device *pdev) 857 { 858 struct spi_controller *host; 859 struct davinci_spi *dspi; 860 struct davinci_spi_platform_data *pdata; 861 struct resource *r; 862 int ret = 0; 863 u32 spipc0; 864 865 host = spi_alloc_host(&pdev->dev, sizeof(struct davinci_spi)); 866 if (host == NULL) { 867 ret = -ENOMEM; 868 goto err; 869 } 870 871 platform_set_drvdata(pdev, host); 872 873 dspi = spi_controller_get_devdata(host); 874 875 if (dev_get_platdata(&pdev->dev)) { 876 pdata = dev_get_platdata(&pdev->dev); 877 dspi->pdata = *pdata; 878 } else { 879 /* update dspi pdata with that from the DT */ 880 ret = spi_davinci_get_pdata(pdev, dspi); 881 if (ret < 0) 882 goto free_host; 883 } 884 885 /* pdata in dspi is now updated and point pdata to that */ 886 pdata = &dspi->pdata; 887 888 dspi->bytes_per_word = devm_kcalloc(&pdev->dev, 889 pdata->num_chipselect, 890 sizeof(*dspi->bytes_per_word), 891 GFP_KERNEL); 892 if (dspi->bytes_per_word == NULL) { 893 ret = -ENOMEM; 894 goto free_host; 895 } 896 897 dspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &r); 898 if (IS_ERR(dspi->base)) { 899 ret = PTR_ERR(dspi->base); 900 goto free_host; 901 } 902 dspi->pbase = r->start; 903 904 init_completion(&dspi->done); 905 906 ret = platform_get_irq(pdev, 0); 907 if (ret < 0) 908 goto free_host; 909 dspi->irq = ret; 910 911 ret = devm_request_threaded_irq(&pdev->dev, dspi->irq, davinci_spi_irq, 912 dummy_thread_fn, 0, dev_name(&pdev->dev), dspi); 913 if (ret) 914 goto free_host; 915 916 dspi->bitbang.master = host; 917 918 dspi->clk = devm_clk_get(&pdev->dev, NULL); 919 if (IS_ERR(dspi->clk)) { 920 ret = -ENODEV; 921 goto free_host; 922 } 923 ret = clk_prepare_enable(dspi->clk); 924 if (ret) 925 goto free_host; 926 927 host->use_gpio_descriptors = true; 928 host->dev.of_node = pdev->dev.of_node; 929 host->bus_num = pdev->id; 930 host->num_chipselect = pdata->num_chipselect; 931 host->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 16); 932 host->flags = SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_GPIO_SS; 933 host->setup = davinci_spi_setup; 934 host->cleanup = davinci_spi_cleanup; 935 host->can_dma = davinci_spi_can_dma; 936 937 dspi->bitbang.chipselect = davinci_spi_chipselect; 938 dspi->bitbang.setup_transfer = davinci_spi_setup_transfer; 939 dspi->prescaler_limit = pdata->prescaler_limit; 940 dspi->version = pdata->version; 941 942 dspi->bitbang.flags = SPI_NO_CS | SPI_LSB_FIRST | SPI_LOOP | SPI_CS_WORD; 943 if (dspi->version == SPI_VERSION_2) 944 dspi->bitbang.flags |= SPI_READY; 945 946 dspi->bitbang.txrx_bufs = davinci_spi_bufs; 947 948 ret = davinci_spi_request_dma(dspi); 949 if (ret == -EPROBE_DEFER) { 950 goto free_clk; 951 } else if (ret) { 952 dev_info(&pdev->dev, "DMA is not supported (%d)\n", ret); 953 dspi->dma_rx = NULL; 954 dspi->dma_tx = NULL; 955 } 956 957 dspi->get_rx = davinci_spi_rx_buf_u8; 958 dspi->get_tx = davinci_spi_tx_buf_u8; 959 960 /* Reset In/OUT SPI module */ 961 iowrite32(0, dspi->base + SPIGCR0); 962 udelay(100); 963 iowrite32(1, dspi->base + SPIGCR0); 964 965 /* Set up SPIPC0. CS and ENA init is done in davinci_spi_setup */ 966 spipc0 = SPIPC0_DIFUN_MASK | SPIPC0_DOFUN_MASK | SPIPC0_CLKFUN_MASK; 967 iowrite32(spipc0, dspi->base + SPIPC0); 968 969 if (pdata->intr_line) 970 iowrite32(SPI_INTLVL_1, dspi->base + SPILVL); 971 else 972 iowrite32(SPI_INTLVL_0, dspi->base + SPILVL); 973 974 iowrite32(CS_DEFAULT, dspi->base + SPIDEF); 975 976 /* host mode default */ 977 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_CLKMOD_MASK); 978 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_MASTER_MASK); 979 set_io_bits(dspi->base + SPIGCR1, SPIGCR1_POWERDOWN_MASK); 980 981 ret = spi_bitbang_start(&dspi->bitbang); 982 if (ret) 983 goto free_dma; 984 985 dev_info(&pdev->dev, "Controller at 0x%p\n", dspi->base); 986 987 return ret; 988 989 free_dma: 990 if (dspi->dma_rx) { 991 dma_release_channel(dspi->dma_rx); 992 dma_release_channel(dspi->dma_tx); 993 } 994 free_clk: 995 clk_disable_unprepare(dspi->clk); 996 free_host: 997 spi_controller_put(host); 998 err: 999 return ret; 1000 } 1001 1002 /** 1003 * davinci_spi_remove - remove function for SPI Master Controller 1004 * @pdev: platform_device structure which contains plateform specific data 1005 * 1006 * This function will do the reverse action of davinci_spi_probe function 1007 * It will free the IRQ and SPI controller's memory region. 1008 * It will also call spi_bitbang_stop to destroy the work queue which was 1009 * created by spi_bitbang_start. 1010 */ 1011 static void davinci_spi_remove(struct platform_device *pdev) 1012 { 1013 struct davinci_spi *dspi; 1014 struct spi_controller *host; 1015 1016 host = platform_get_drvdata(pdev); 1017 dspi = spi_controller_get_devdata(host); 1018 1019 spi_bitbang_stop(&dspi->bitbang); 1020 1021 clk_disable_unprepare(dspi->clk); 1022 1023 if (dspi->dma_rx) { 1024 dma_release_channel(dspi->dma_rx); 1025 dma_release_channel(dspi->dma_tx); 1026 } 1027 1028 spi_controller_put(host); 1029 } 1030 1031 static struct platform_driver davinci_spi_driver = { 1032 .driver = { 1033 .name = "spi_davinci", 1034 .of_match_table = of_match_ptr(davinci_spi_of_match), 1035 }, 1036 .probe = davinci_spi_probe, 1037 .remove_new = davinci_spi_remove, 1038 }; 1039 module_platform_driver(davinci_spi_driver); 1040 1041 MODULE_DESCRIPTION("TI DaVinci SPI Master Controller Driver"); 1042 MODULE_LICENSE("GPL"); 1043