1 /* 2 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write to the Free Software 16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 17 */ 18 19 #include <linux/init.h> 20 #include <linux/module.h> 21 #include <linux/device.h> 22 #include <linux/ioport.h> 23 #include <linux/errno.h> 24 #include <linux/interrupt.h> 25 #include <linux/platform_device.h> 26 #include <linux/spi/pxa2xx_spi.h> 27 #include <linux/dma-mapping.h> 28 #include <linux/spi/spi.h> 29 #include <linux/workqueue.h> 30 #include <linux/delay.h> 31 #include <linux/gpio.h> 32 #include <linux/slab.h> 33 34 #include <asm/io.h> 35 #include <asm/irq.h> 36 #include <asm/delay.h> 37 38 39 MODULE_AUTHOR("Stephen Street"); 40 MODULE_DESCRIPTION("PXA2xx SSP SPI Controller"); 41 MODULE_LICENSE("GPL"); 42 MODULE_ALIAS("platform:pxa2xx-spi"); 43 44 #define MAX_BUSES 3 45 46 #define TIMOUT_DFLT 1000 47 48 #define DMA_INT_MASK (DCSR_ENDINTR | DCSR_STARTINTR | DCSR_BUSERR) 49 #define RESET_DMA_CHANNEL (DCSR_NODESC | DMA_INT_MASK) 50 #define IS_DMA_ALIGNED(x) ((((u32)(x)) & 0x07) == 0) 51 #define MAX_DMA_LEN 8191 52 #define DMA_ALIGNMENT 8 53 54 /* 55 * for testing SSCR1 changes that require SSP restart, basically 56 * everything except the service and interrupt enables, the pxa270 developer 57 * manual says only SSCR1_SCFR, SSCR1_SPH, SSCR1_SPO need to be in this 58 * list, but the PXA255 dev man says all bits without really meaning the 59 * service and interrupt enables 60 */ 61 #define SSCR1_CHANGE_MASK (SSCR1_TTELP | SSCR1_TTE | SSCR1_SCFR \ 62 | SSCR1_ECRA | SSCR1_ECRB | SSCR1_SCLKDIR \ 63 | SSCR1_SFRMDIR | SSCR1_RWOT | SSCR1_TRAIL \ 64 | SSCR1_IFS | SSCR1_STRF | SSCR1_EFWR \ 65 | SSCR1_RFT | SSCR1_TFT | SSCR1_MWDS \ 66 | SSCR1_SPH | SSCR1_SPO | SSCR1_LBM) 67 68 #define DEFINE_SSP_REG(reg, off) \ 69 static inline u32 read_##reg(void const __iomem *p) \ 70 { return __raw_readl(p + (off)); } \ 71 \ 72 static inline void write_##reg(u32 v, void __iomem *p) \ 73 { __raw_writel(v, p + (off)); } 74 75 DEFINE_SSP_REG(SSCR0, 0x00) 76 DEFINE_SSP_REG(SSCR1, 0x04) 77 DEFINE_SSP_REG(SSSR, 0x08) 78 DEFINE_SSP_REG(SSITR, 0x0c) 79 DEFINE_SSP_REG(SSDR, 0x10) 80 DEFINE_SSP_REG(SSTO, 0x28) 81 DEFINE_SSP_REG(SSPSP, 0x2c) 82 83 #define START_STATE ((void*)0) 84 #define RUNNING_STATE ((void*)1) 85 #define DONE_STATE ((void*)2) 86 #define ERROR_STATE ((void*)-1) 87 88 #define QUEUE_RUNNING 0 89 #define QUEUE_STOPPED 1 90 91 struct driver_data { 92 /* Driver model hookup */ 93 struct platform_device *pdev; 94 95 /* SSP Info */ 96 struct ssp_device *ssp; 97 98 /* SPI framework hookup */ 99 enum pxa_ssp_type ssp_type; 100 struct spi_master *master; 101 102 /* PXA hookup */ 103 struct pxa2xx_spi_master *master_info; 104 105 /* DMA setup stuff */ 106 int rx_channel; 107 int tx_channel; 108 u32 *null_dma_buf; 109 110 /* SSP register addresses */ 111 void __iomem *ioaddr; 112 u32 ssdr_physical; 113 114 /* SSP masks*/ 115 u32 dma_cr1; 116 u32 int_cr1; 117 u32 clear_sr; 118 u32 mask_sr; 119 120 /* Driver message queue */ 121 struct workqueue_struct *workqueue; 122 struct work_struct pump_messages; 123 spinlock_t lock; 124 struct list_head queue; 125 int busy; 126 int run; 127 128 /* Message Transfer pump */ 129 struct tasklet_struct pump_transfers; 130 131 /* Current message transfer state info */ 132 struct spi_message* cur_msg; 133 struct spi_transfer* cur_transfer; 134 struct chip_data *cur_chip; 135 size_t len; 136 void *tx; 137 void *tx_end; 138 void *rx; 139 void *rx_end; 140 int dma_mapped; 141 dma_addr_t rx_dma; 142 dma_addr_t tx_dma; 143 size_t rx_map_len; 144 size_t tx_map_len; 145 u8 n_bytes; 146 u32 dma_width; 147 int (*write)(struct driver_data *drv_data); 148 int (*read)(struct driver_data *drv_data); 149 irqreturn_t (*transfer_handler)(struct driver_data *drv_data); 150 void (*cs_control)(u32 command); 151 }; 152 153 struct chip_data { 154 u32 cr0; 155 u32 cr1; 156 u32 psp; 157 u32 timeout; 158 u8 n_bytes; 159 u32 dma_width; 160 u32 dma_burst_size; 161 u32 threshold; 162 u32 dma_threshold; 163 u8 enable_dma; 164 u8 bits_per_word; 165 u32 speed_hz; 166 union { 167 int gpio_cs; 168 unsigned int frm; 169 }; 170 int gpio_cs_inverted; 171 int (*write)(struct driver_data *drv_data); 172 int (*read)(struct driver_data *drv_data); 173 void (*cs_control)(u32 command); 174 }; 175 176 static void pump_messages(struct work_struct *work); 177 178 static void cs_assert(struct driver_data *drv_data) 179 { 180 struct chip_data *chip = drv_data->cur_chip; 181 182 if (drv_data->ssp_type == CE4100_SSP) { 183 write_SSSR(drv_data->cur_chip->frm, drv_data->ioaddr); 184 return; 185 } 186 187 if (chip->cs_control) { 188 chip->cs_control(PXA2XX_CS_ASSERT); 189 return; 190 } 191 192 if (gpio_is_valid(chip->gpio_cs)) 193 gpio_set_value(chip->gpio_cs, chip->gpio_cs_inverted); 194 } 195 196 static void cs_deassert(struct driver_data *drv_data) 197 { 198 struct chip_data *chip = drv_data->cur_chip; 199 200 if (drv_data->ssp_type == CE4100_SSP) 201 return; 202 203 if (chip->cs_control) { 204 chip->cs_control(PXA2XX_CS_DEASSERT); 205 return; 206 } 207 208 if (gpio_is_valid(chip->gpio_cs)) 209 gpio_set_value(chip->gpio_cs, !chip->gpio_cs_inverted); 210 } 211 212 static void write_SSSR_CS(struct driver_data *drv_data, u32 val) 213 { 214 void __iomem *reg = drv_data->ioaddr; 215 216 if (drv_data->ssp_type == CE4100_SSP) 217 val |= read_SSSR(reg) & SSSR_ALT_FRM_MASK; 218 219 write_SSSR(val, reg); 220 } 221 222 static int pxa25x_ssp_comp(struct driver_data *drv_data) 223 { 224 if (drv_data->ssp_type == PXA25x_SSP) 225 return 1; 226 if (drv_data->ssp_type == CE4100_SSP) 227 return 1; 228 return 0; 229 } 230 231 static int flush(struct driver_data *drv_data) 232 { 233 unsigned long limit = loops_per_jiffy << 1; 234 235 void __iomem *reg = drv_data->ioaddr; 236 237 do { 238 while (read_SSSR(reg) & SSSR_RNE) { 239 read_SSDR(reg); 240 } 241 } while ((read_SSSR(reg) & SSSR_BSY) && --limit); 242 write_SSSR_CS(drv_data, SSSR_ROR); 243 244 return limit; 245 } 246 247 static int null_writer(struct driver_data *drv_data) 248 { 249 void __iomem *reg = drv_data->ioaddr; 250 u8 n_bytes = drv_data->n_bytes; 251 252 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK) 253 || (drv_data->tx == drv_data->tx_end)) 254 return 0; 255 256 write_SSDR(0, reg); 257 drv_data->tx += n_bytes; 258 259 return 1; 260 } 261 262 static int null_reader(struct driver_data *drv_data) 263 { 264 void __iomem *reg = drv_data->ioaddr; 265 u8 n_bytes = drv_data->n_bytes; 266 267 while ((read_SSSR(reg) & SSSR_RNE) 268 && (drv_data->rx < drv_data->rx_end)) { 269 read_SSDR(reg); 270 drv_data->rx += n_bytes; 271 } 272 273 return drv_data->rx == drv_data->rx_end; 274 } 275 276 static int u8_writer(struct driver_data *drv_data) 277 { 278 void __iomem *reg = drv_data->ioaddr; 279 280 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK) 281 || (drv_data->tx == drv_data->tx_end)) 282 return 0; 283 284 write_SSDR(*(u8 *)(drv_data->tx), reg); 285 ++drv_data->tx; 286 287 return 1; 288 } 289 290 static int u8_reader(struct driver_data *drv_data) 291 { 292 void __iomem *reg = drv_data->ioaddr; 293 294 while ((read_SSSR(reg) & SSSR_RNE) 295 && (drv_data->rx < drv_data->rx_end)) { 296 *(u8 *)(drv_data->rx) = read_SSDR(reg); 297 ++drv_data->rx; 298 } 299 300 return drv_data->rx == drv_data->rx_end; 301 } 302 303 static int u16_writer(struct driver_data *drv_data) 304 { 305 void __iomem *reg = drv_data->ioaddr; 306 307 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK) 308 || (drv_data->tx == drv_data->tx_end)) 309 return 0; 310 311 write_SSDR(*(u16 *)(drv_data->tx), reg); 312 drv_data->tx += 2; 313 314 return 1; 315 } 316 317 static int u16_reader(struct driver_data *drv_data) 318 { 319 void __iomem *reg = drv_data->ioaddr; 320 321 while ((read_SSSR(reg) & SSSR_RNE) 322 && (drv_data->rx < drv_data->rx_end)) { 323 *(u16 *)(drv_data->rx) = read_SSDR(reg); 324 drv_data->rx += 2; 325 } 326 327 return drv_data->rx == drv_data->rx_end; 328 } 329 330 static int u32_writer(struct driver_data *drv_data) 331 { 332 void __iomem *reg = drv_data->ioaddr; 333 334 if (((read_SSSR(reg) & SSSR_TFL_MASK) == SSSR_TFL_MASK) 335 || (drv_data->tx == drv_data->tx_end)) 336 return 0; 337 338 write_SSDR(*(u32 *)(drv_data->tx), reg); 339 drv_data->tx += 4; 340 341 return 1; 342 } 343 344 static int u32_reader(struct driver_data *drv_data) 345 { 346 void __iomem *reg = drv_data->ioaddr; 347 348 while ((read_SSSR(reg) & SSSR_RNE) 349 && (drv_data->rx < drv_data->rx_end)) { 350 *(u32 *)(drv_data->rx) = read_SSDR(reg); 351 drv_data->rx += 4; 352 } 353 354 return drv_data->rx == drv_data->rx_end; 355 } 356 357 static void *next_transfer(struct driver_data *drv_data) 358 { 359 struct spi_message *msg = drv_data->cur_msg; 360 struct spi_transfer *trans = drv_data->cur_transfer; 361 362 /* Move to next transfer */ 363 if (trans->transfer_list.next != &msg->transfers) { 364 drv_data->cur_transfer = 365 list_entry(trans->transfer_list.next, 366 struct spi_transfer, 367 transfer_list); 368 return RUNNING_STATE; 369 } else 370 return DONE_STATE; 371 } 372 373 static int map_dma_buffers(struct driver_data *drv_data) 374 { 375 struct spi_message *msg = drv_data->cur_msg; 376 struct device *dev = &msg->spi->dev; 377 378 if (!drv_data->cur_chip->enable_dma) 379 return 0; 380 381 if (msg->is_dma_mapped) 382 return drv_data->rx_dma && drv_data->tx_dma; 383 384 if (!IS_DMA_ALIGNED(drv_data->rx) || !IS_DMA_ALIGNED(drv_data->tx)) 385 return 0; 386 387 /* Modify setup if rx buffer is null */ 388 if (drv_data->rx == NULL) { 389 *drv_data->null_dma_buf = 0; 390 drv_data->rx = drv_data->null_dma_buf; 391 drv_data->rx_map_len = 4; 392 } else 393 drv_data->rx_map_len = drv_data->len; 394 395 396 /* Modify setup if tx buffer is null */ 397 if (drv_data->tx == NULL) { 398 *drv_data->null_dma_buf = 0; 399 drv_data->tx = drv_data->null_dma_buf; 400 drv_data->tx_map_len = 4; 401 } else 402 drv_data->tx_map_len = drv_data->len; 403 404 /* Stream map the tx buffer. Always do DMA_TO_DEVICE first 405 * so we flush the cache *before* invalidating it, in case 406 * the tx and rx buffers overlap. 407 */ 408 drv_data->tx_dma = dma_map_single(dev, drv_data->tx, 409 drv_data->tx_map_len, DMA_TO_DEVICE); 410 if (dma_mapping_error(dev, drv_data->tx_dma)) 411 return 0; 412 413 /* Stream map the rx buffer */ 414 drv_data->rx_dma = dma_map_single(dev, drv_data->rx, 415 drv_data->rx_map_len, DMA_FROM_DEVICE); 416 if (dma_mapping_error(dev, drv_data->rx_dma)) { 417 dma_unmap_single(dev, drv_data->tx_dma, 418 drv_data->tx_map_len, DMA_TO_DEVICE); 419 return 0; 420 } 421 422 return 1; 423 } 424 425 static void unmap_dma_buffers(struct driver_data *drv_data) 426 { 427 struct device *dev; 428 429 if (!drv_data->dma_mapped) 430 return; 431 432 if (!drv_data->cur_msg->is_dma_mapped) { 433 dev = &drv_data->cur_msg->spi->dev; 434 dma_unmap_single(dev, drv_data->rx_dma, 435 drv_data->rx_map_len, DMA_FROM_DEVICE); 436 dma_unmap_single(dev, drv_data->tx_dma, 437 drv_data->tx_map_len, DMA_TO_DEVICE); 438 } 439 440 drv_data->dma_mapped = 0; 441 } 442 443 /* caller already set message->status; dma and pio irqs are blocked */ 444 static void giveback(struct driver_data *drv_data) 445 { 446 struct spi_transfer* last_transfer; 447 unsigned long flags; 448 struct spi_message *msg; 449 450 spin_lock_irqsave(&drv_data->lock, flags); 451 msg = drv_data->cur_msg; 452 drv_data->cur_msg = NULL; 453 drv_data->cur_transfer = NULL; 454 queue_work(drv_data->workqueue, &drv_data->pump_messages); 455 spin_unlock_irqrestore(&drv_data->lock, flags); 456 457 last_transfer = list_entry(msg->transfers.prev, 458 struct spi_transfer, 459 transfer_list); 460 461 /* Delay if requested before any change in chip select */ 462 if (last_transfer->delay_usecs) 463 udelay(last_transfer->delay_usecs); 464 465 /* Drop chip select UNLESS cs_change is true or we are returning 466 * a message with an error, or next message is for another chip 467 */ 468 if (!last_transfer->cs_change) 469 cs_deassert(drv_data); 470 else { 471 struct spi_message *next_msg; 472 473 /* Holding of cs was hinted, but we need to make sure 474 * the next message is for the same chip. Don't waste 475 * time with the following tests unless this was hinted. 476 * 477 * We cannot postpone this until pump_messages, because 478 * after calling msg->complete (below) the driver that 479 * sent the current message could be unloaded, which 480 * could invalidate the cs_control() callback... 481 */ 482 483 /* get a pointer to the next message, if any */ 484 spin_lock_irqsave(&drv_data->lock, flags); 485 if (list_empty(&drv_data->queue)) 486 next_msg = NULL; 487 else 488 next_msg = list_entry(drv_data->queue.next, 489 struct spi_message, queue); 490 spin_unlock_irqrestore(&drv_data->lock, flags); 491 492 /* see if the next and current messages point 493 * to the same chip 494 */ 495 if (next_msg && next_msg->spi != msg->spi) 496 next_msg = NULL; 497 if (!next_msg || msg->state == ERROR_STATE) 498 cs_deassert(drv_data); 499 } 500 501 msg->state = NULL; 502 if (msg->complete) 503 msg->complete(msg->context); 504 505 drv_data->cur_chip = NULL; 506 } 507 508 static int wait_ssp_rx_stall(void const __iomem *ioaddr) 509 { 510 unsigned long limit = loops_per_jiffy << 1; 511 512 while ((read_SSSR(ioaddr) & SSSR_BSY) && --limit) 513 cpu_relax(); 514 515 return limit; 516 } 517 518 static int wait_dma_channel_stop(int channel) 519 { 520 unsigned long limit = loops_per_jiffy << 1; 521 522 while (!(DCSR(channel) & DCSR_STOPSTATE) && --limit) 523 cpu_relax(); 524 525 return limit; 526 } 527 528 static void dma_error_stop(struct driver_data *drv_data, const char *msg) 529 { 530 void __iomem *reg = drv_data->ioaddr; 531 532 /* Stop and reset */ 533 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; 534 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; 535 write_SSSR_CS(drv_data, drv_data->clear_sr); 536 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); 537 if (!pxa25x_ssp_comp(drv_data)) 538 write_SSTO(0, reg); 539 flush(drv_data); 540 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); 541 542 unmap_dma_buffers(drv_data); 543 544 dev_err(&drv_data->pdev->dev, "%s\n", msg); 545 546 drv_data->cur_msg->state = ERROR_STATE; 547 tasklet_schedule(&drv_data->pump_transfers); 548 } 549 550 static void dma_transfer_complete(struct driver_data *drv_data) 551 { 552 void __iomem *reg = drv_data->ioaddr; 553 struct spi_message *msg = drv_data->cur_msg; 554 555 /* Clear and disable interrupts on SSP and DMA channels*/ 556 write_SSCR1(read_SSCR1(reg) & ~drv_data->dma_cr1, reg); 557 write_SSSR_CS(drv_data, drv_data->clear_sr); 558 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; 559 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; 560 561 if (wait_dma_channel_stop(drv_data->rx_channel) == 0) 562 dev_err(&drv_data->pdev->dev, 563 "dma_handler: dma rx channel stop failed\n"); 564 565 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) 566 dev_err(&drv_data->pdev->dev, 567 "dma_transfer: ssp rx stall failed\n"); 568 569 unmap_dma_buffers(drv_data); 570 571 /* update the buffer pointer for the amount completed in dma */ 572 drv_data->rx += drv_data->len - 573 (DCMD(drv_data->rx_channel) & DCMD_LENGTH); 574 575 /* read trailing data from fifo, it does not matter how many 576 * bytes are in the fifo just read until buffer is full 577 * or fifo is empty, which ever occurs first */ 578 drv_data->read(drv_data); 579 580 /* return count of what was actually read */ 581 msg->actual_length += drv_data->len - 582 (drv_data->rx_end - drv_data->rx); 583 584 /* Transfer delays and chip select release are 585 * handled in pump_transfers or giveback 586 */ 587 588 /* Move to next transfer */ 589 msg->state = next_transfer(drv_data); 590 591 /* Schedule transfer tasklet */ 592 tasklet_schedule(&drv_data->pump_transfers); 593 } 594 595 static void dma_handler(int channel, void *data) 596 { 597 struct driver_data *drv_data = data; 598 u32 irq_status = DCSR(channel) & DMA_INT_MASK; 599 600 if (irq_status & DCSR_BUSERR) { 601 602 if (channel == drv_data->tx_channel) 603 dma_error_stop(drv_data, 604 "dma_handler: " 605 "bad bus address on tx channel"); 606 else 607 dma_error_stop(drv_data, 608 "dma_handler: " 609 "bad bus address on rx channel"); 610 return; 611 } 612 613 /* PXA255x_SSP has no timeout interrupt, wait for tailing bytes */ 614 if ((channel == drv_data->tx_channel) 615 && (irq_status & DCSR_ENDINTR) 616 && (drv_data->ssp_type == PXA25x_SSP)) { 617 618 /* Wait for rx to stall */ 619 if (wait_ssp_rx_stall(drv_data->ioaddr) == 0) 620 dev_err(&drv_data->pdev->dev, 621 "dma_handler: ssp rx stall failed\n"); 622 623 /* finish this transfer, start the next */ 624 dma_transfer_complete(drv_data); 625 } 626 } 627 628 static irqreturn_t dma_transfer(struct driver_data *drv_data) 629 { 630 u32 irq_status; 631 void __iomem *reg = drv_data->ioaddr; 632 633 irq_status = read_SSSR(reg) & drv_data->mask_sr; 634 if (irq_status & SSSR_ROR) { 635 dma_error_stop(drv_data, "dma_transfer: fifo overrun"); 636 return IRQ_HANDLED; 637 } 638 639 /* Check for false positive timeout */ 640 if ((irq_status & SSSR_TINT) 641 && (DCSR(drv_data->tx_channel) & DCSR_RUN)) { 642 write_SSSR(SSSR_TINT, reg); 643 return IRQ_HANDLED; 644 } 645 646 if (irq_status & SSSR_TINT || drv_data->rx == drv_data->rx_end) { 647 648 /* Clear and disable timeout interrupt, do the rest in 649 * dma_transfer_complete */ 650 if (!pxa25x_ssp_comp(drv_data)) 651 write_SSTO(0, reg); 652 653 /* finish this transfer, start the next */ 654 dma_transfer_complete(drv_data); 655 656 return IRQ_HANDLED; 657 } 658 659 /* Opps problem detected */ 660 return IRQ_NONE; 661 } 662 663 static void reset_sccr1(struct driver_data *drv_data) 664 { 665 void __iomem *reg = drv_data->ioaddr; 666 struct chip_data *chip = drv_data->cur_chip; 667 u32 sccr1_reg; 668 669 sccr1_reg = read_SSCR1(reg) & ~drv_data->int_cr1; 670 sccr1_reg &= ~SSCR1_RFT; 671 sccr1_reg |= chip->threshold; 672 write_SSCR1(sccr1_reg, reg); 673 } 674 675 static void int_error_stop(struct driver_data *drv_data, const char* msg) 676 { 677 void __iomem *reg = drv_data->ioaddr; 678 679 /* Stop and reset SSP */ 680 write_SSSR_CS(drv_data, drv_data->clear_sr); 681 reset_sccr1(drv_data); 682 if (!pxa25x_ssp_comp(drv_data)) 683 write_SSTO(0, reg); 684 flush(drv_data); 685 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); 686 687 dev_err(&drv_data->pdev->dev, "%s\n", msg); 688 689 drv_data->cur_msg->state = ERROR_STATE; 690 tasklet_schedule(&drv_data->pump_transfers); 691 } 692 693 static void int_transfer_complete(struct driver_data *drv_data) 694 { 695 void __iomem *reg = drv_data->ioaddr; 696 697 /* Stop SSP */ 698 write_SSSR_CS(drv_data, drv_data->clear_sr); 699 reset_sccr1(drv_data); 700 if (!pxa25x_ssp_comp(drv_data)) 701 write_SSTO(0, reg); 702 703 /* Update total byte transferred return count actual bytes read */ 704 drv_data->cur_msg->actual_length += drv_data->len - 705 (drv_data->rx_end - drv_data->rx); 706 707 /* Transfer delays and chip select release are 708 * handled in pump_transfers or giveback 709 */ 710 711 /* Move to next transfer */ 712 drv_data->cur_msg->state = next_transfer(drv_data); 713 714 /* Schedule transfer tasklet */ 715 tasklet_schedule(&drv_data->pump_transfers); 716 } 717 718 static irqreturn_t interrupt_transfer(struct driver_data *drv_data) 719 { 720 void __iomem *reg = drv_data->ioaddr; 721 722 u32 irq_mask = (read_SSCR1(reg) & SSCR1_TIE) ? 723 drv_data->mask_sr : drv_data->mask_sr & ~SSSR_TFS; 724 725 u32 irq_status = read_SSSR(reg) & irq_mask; 726 727 if (irq_status & SSSR_ROR) { 728 int_error_stop(drv_data, "interrupt_transfer: fifo overrun"); 729 return IRQ_HANDLED; 730 } 731 732 if (irq_status & SSSR_TINT) { 733 write_SSSR(SSSR_TINT, reg); 734 if (drv_data->read(drv_data)) { 735 int_transfer_complete(drv_data); 736 return IRQ_HANDLED; 737 } 738 } 739 740 /* Drain rx fifo, Fill tx fifo and prevent overruns */ 741 do { 742 if (drv_data->read(drv_data)) { 743 int_transfer_complete(drv_data); 744 return IRQ_HANDLED; 745 } 746 } while (drv_data->write(drv_data)); 747 748 if (drv_data->read(drv_data)) { 749 int_transfer_complete(drv_data); 750 return IRQ_HANDLED; 751 } 752 753 if (drv_data->tx == drv_data->tx_end) { 754 u32 bytes_left; 755 u32 sccr1_reg; 756 757 sccr1_reg = read_SSCR1(reg); 758 sccr1_reg &= ~SSCR1_TIE; 759 760 /* 761 * PXA25x_SSP has no timeout, set up rx threshould for the 762 * remaining RX bytes. 763 */ 764 if (pxa25x_ssp_comp(drv_data)) { 765 766 sccr1_reg &= ~SSCR1_RFT; 767 768 bytes_left = drv_data->rx_end - drv_data->rx; 769 switch (drv_data->n_bytes) { 770 case 4: 771 bytes_left >>= 1; 772 case 2: 773 bytes_left >>= 1; 774 } 775 776 if (bytes_left > RX_THRESH_DFLT) 777 bytes_left = RX_THRESH_DFLT; 778 779 sccr1_reg |= SSCR1_RxTresh(bytes_left); 780 } 781 write_SSCR1(sccr1_reg, reg); 782 } 783 784 /* We did something */ 785 return IRQ_HANDLED; 786 } 787 788 static irqreturn_t ssp_int(int irq, void *dev_id) 789 { 790 struct driver_data *drv_data = dev_id; 791 void __iomem *reg = drv_data->ioaddr; 792 u32 sccr1_reg = read_SSCR1(reg); 793 u32 mask = drv_data->mask_sr; 794 u32 status; 795 796 status = read_SSSR(reg); 797 798 /* Ignore possible writes if we don't need to write */ 799 if (!(sccr1_reg & SSCR1_TIE)) 800 mask &= ~SSSR_TFS; 801 802 if (!(status & mask)) 803 return IRQ_NONE; 804 805 if (!drv_data->cur_msg) { 806 807 write_SSCR0(read_SSCR0(reg) & ~SSCR0_SSE, reg); 808 write_SSCR1(read_SSCR1(reg) & ~drv_data->int_cr1, reg); 809 if (!pxa25x_ssp_comp(drv_data)) 810 write_SSTO(0, reg); 811 write_SSSR_CS(drv_data, drv_data->clear_sr); 812 813 dev_err(&drv_data->pdev->dev, "bad message state " 814 "in interrupt handler\n"); 815 816 /* Never fail */ 817 return IRQ_HANDLED; 818 } 819 820 return drv_data->transfer_handler(drv_data); 821 } 822 823 static int set_dma_burst_and_threshold(struct chip_data *chip, 824 struct spi_device *spi, 825 u8 bits_per_word, u32 *burst_code, 826 u32 *threshold) 827 { 828 struct pxa2xx_spi_chip *chip_info = 829 (struct pxa2xx_spi_chip *)spi->controller_data; 830 int bytes_per_word; 831 int burst_bytes; 832 int thresh_words; 833 int req_burst_size; 834 int retval = 0; 835 836 /* Set the threshold (in registers) to equal the same amount of data 837 * as represented by burst size (in bytes). The computation below 838 * is (burst_size rounded up to nearest 8 byte, word or long word) 839 * divided by (bytes/register); the tx threshold is the inverse of 840 * the rx, so that there will always be enough data in the rx fifo 841 * to satisfy a burst, and there will always be enough space in the 842 * tx fifo to accept a burst (a tx burst will overwrite the fifo if 843 * there is not enough space), there must always remain enough empty 844 * space in the rx fifo for any data loaded to the tx fifo. 845 * Whenever burst_size (in bytes) equals bits/word, the fifo threshold 846 * will be 8, or half the fifo; 847 * The threshold can only be set to 2, 4 or 8, but not 16, because 848 * to burst 16 to the tx fifo, the fifo would have to be empty; 849 * however, the minimum fifo trigger level is 1, and the tx will 850 * request service when the fifo is at this level, with only 15 spaces. 851 */ 852 853 /* find bytes/word */ 854 if (bits_per_word <= 8) 855 bytes_per_word = 1; 856 else if (bits_per_word <= 16) 857 bytes_per_word = 2; 858 else 859 bytes_per_word = 4; 860 861 /* use struct pxa2xx_spi_chip->dma_burst_size if available */ 862 if (chip_info) 863 req_burst_size = chip_info->dma_burst_size; 864 else { 865 switch (chip->dma_burst_size) { 866 default: 867 /* if the default burst size is not set, 868 * do it now */ 869 chip->dma_burst_size = DCMD_BURST8; 870 case DCMD_BURST8: 871 req_burst_size = 8; 872 break; 873 case DCMD_BURST16: 874 req_burst_size = 16; 875 break; 876 case DCMD_BURST32: 877 req_burst_size = 32; 878 break; 879 } 880 } 881 if (req_burst_size <= 8) { 882 *burst_code = DCMD_BURST8; 883 burst_bytes = 8; 884 } else if (req_burst_size <= 16) { 885 if (bytes_per_word == 1) { 886 /* don't burst more than 1/2 the fifo */ 887 *burst_code = DCMD_BURST8; 888 burst_bytes = 8; 889 retval = 1; 890 } else { 891 *burst_code = DCMD_BURST16; 892 burst_bytes = 16; 893 } 894 } else { 895 if (bytes_per_word == 1) { 896 /* don't burst more than 1/2 the fifo */ 897 *burst_code = DCMD_BURST8; 898 burst_bytes = 8; 899 retval = 1; 900 } else if (bytes_per_word == 2) { 901 /* don't burst more than 1/2 the fifo */ 902 *burst_code = DCMD_BURST16; 903 burst_bytes = 16; 904 retval = 1; 905 } else { 906 *burst_code = DCMD_BURST32; 907 burst_bytes = 32; 908 } 909 } 910 911 thresh_words = burst_bytes / bytes_per_word; 912 913 /* thresh_words will be between 2 and 8 */ 914 *threshold = (SSCR1_RxTresh(thresh_words) & SSCR1_RFT) 915 | (SSCR1_TxTresh(16-thresh_words) & SSCR1_TFT); 916 917 return retval; 918 } 919 920 static unsigned int ssp_get_clk_div(struct ssp_device *ssp, int rate) 921 { 922 unsigned long ssp_clk = clk_get_rate(ssp->clk); 923 924 if (ssp->type == PXA25x_SSP || ssp->type == CE4100_SSP) 925 return ((ssp_clk / (2 * rate) - 1) & 0xff) << 8; 926 else 927 return ((ssp_clk / rate - 1) & 0xfff) << 8; 928 } 929 930 static void pump_transfers(unsigned long data) 931 { 932 struct driver_data *drv_data = (struct driver_data *)data; 933 struct spi_message *message = NULL; 934 struct spi_transfer *transfer = NULL; 935 struct spi_transfer *previous = NULL; 936 struct chip_data *chip = NULL; 937 struct ssp_device *ssp = drv_data->ssp; 938 void __iomem *reg = drv_data->ioaddr; 939 u32 clk_div = 0; 940 u8 bits = 0; 941 u32 speed = 0; 942 u32 cr0; 943 u32 cr1; 944 u32 dma_thresh = drv_data->cur_chip->dma_threshold; 945 u32 dma_burst = drv_data->cur_chip->dma_burst_size; 946 947 /* Get current state information */ 948 message = drv_data->cur_msg; 949 transfer = drv_data->cur_transfer; 950 chip = drv_data->cur_chip; 951 952 /* Handle for abort */ 953 if (message->state == ERROR_STATE) { 954 message->status = -EIO; 955 giveback(drv_data); 956 return; 957 } 958 959 /* Handle end of message */ 960 if (message->state == DONE_STATE) { 961 message->status = 0; 962 giveback(drv_data); 963 return; 964 } 965 966 /* Delay if requested at end of transfer before CS change */ 967 if (message->state == RUNNING_STATE) { 968 previous = list_entry(transfer->transfer_list.prev, 969 struct spi_transfer, 970 transfer_list); 971 if (previous->delay_usecs) 972 udelay(previous->delay_usecs); 973 974 /* Drop chip select only if cs_change is requested */ 975 if (previous->cs_change) 976 cs_deassert(drv_data); 977 } 978 979 /* Check for transfers that need multiple DMA segments */ 980 if (transfer->len > MAX_DMA_LEN && chip->enable_dma) { 981 982 /* reject already-mapped transfers; PIO won't always work */ 983 if (message->is_dma_mapped 984 || transfer->rx_dma || transfer->tx_dma) { 985 dev_err(&drv_data->pdev->dev, 986 "pump_transfers: mapped transfer length " 987 "of %u is greater than %d\n", 988 transfer->len, MAX_DMA_LEN); 989 message->status = -EINVAL; 990 giveback(drv_data); 991 return; 992 } 993 994 /* warn ... we force this to PIO mode */ 995 if (printk_ratelimit()) 996 dev_warn(&message->spi->dev, "pump_transfers: " 997 "DMA disabled for transfer length %ld " 998 "greater than %d\n", 999 (long)drv_data->len, MAX_DMA_LEN); 1000 } 1001 1002 /* Setup the transfer state based on the type of transfer */ 1003 if (flush(drv_data) == 0) { 1004 dev_err(&drv_data->pdev->dev, "pump_transfers: flush failed\n"); 1005 message->status = -EIO; 1006 giveback(drv_data); 1007 return; 1008 } 1009 drv_data->n_bytes = chip->n_bytes; 1010 drv_data->dma_width = chip->dma_width; 1011 drv_data->tx = (void *)transfer->tx_buf; 1012 drv_data->tx_end = drv_data->tx + transfer->len; 1013 drv_data->rx = transfer->rx_buf; 1014 drv_data->rx_end = drv_data->rx + transfer->len; 1015 drv_data->rx_dma = transfer->rx_dma; 1016 drv_data->tx_dma = transfer->tx_dma; 1017 drv_data->len = transfer->len & DCMD_LENGTH; 1018 drv_data->write = drv_data->tx ? chip->write : null_writer; 1019 drv_data->read = drv_data->rx ? chip->read : null_reader; 1020 1021 /* Change speed and bit per word on a per transfer */ 1022 cr0 = chip->cr0; 1023 if (transfer->speed_hz || transfer->bits_per_word) { 1024 1025 bits = chip->bits_per_word; 1026 speed = chip->speed_hz; 1027 1028 if (transfer->speed_hz) 1029 speed = transfer->speed_hz; 1030 1031 if (transfer->bits_per_word) 1032 bits = transfer->bits_per_word; 1033 1034 clk_div = ssp_get_clk_div(ssp, speed); 1035 1036 if (bits <= 8) { 1037 drv_data->n_bytes = 1; 1038 drv_data->dma_width = DCMD_WIDTH1; 1039 drv_data->read = drv_data->read != null_reader ? 1040 u8_reader : null_reader; 1041 drv_data->write = drv_data->write != null_writer ? 1042 u8_writer : null_writer; 1043 } else if (bits <= 16) { 1044 drv_data->n_bytes = 2; 1045 drv_data->dma_width = DCMD_WIDTH2; 1046 drv_data->read = drv_data->read != null_reader ? 1047 u16_reader : null_reader; 1048 drv_data->write = drv_data->write != null_writer ? 1049 u16_writer : null_writer; 1050 } else if (bits <= 32) { 1051 drv_data->n_bytes = 4; 1052 drv_data->dma_width = DCMD_WIDTH4; 1053 drv_data->read = drv_data->read != null_reader ? 1054 u32_reader : null_reader; 1055 drv_data->write = drv_data->write != null_writer ? 1056 u32_writer : null_writer; 1057 } 1058 /* if bits/word is changed in dma mode, then must check the 1059 * thresholds and burst also */ 1060 if (chip->enable_dma) { 1061 if (set_dma_burst_and_threshold(chip, message->spi, 1062 bits, &dma_burst, 1063 &dma_thresh)) 1064 if (printk_ratelimit()) 1065 dev_warn(&message->spi->dev, 1066 "pump_transfers: " 1067 "DMA burst size reduced to " 1068 "match bits_per_word\n"); 1069 } 1070 1071 cr0 = clk_div 1072 | SSCR0_Motorola 1073 | SSCR0_DataSize(bits > 16 ? bits - 16 : bits) 1074 | SSCR0_SSE 1075 | (bits > 16 ? SSCR0_EDSS : 0); 1076 } 1077 1078 message->state = RUNNING_STATE; 1079 1080 /* Try to map dma buffer and do a dma transfer if successful, but 1081 * only if the length is non-zero and less than MAX_DMA_LEN. 1082 * 1083 * Zero-length non-descriptor DMA is illegal on PXA2xx; force use 1084 * of PIO instead. Care is needed above because the transfer may 1085 * have have been passed with buffers that are already dma mapped. 1086 * A zero-length transfer in PIO mode will not try to write/read 1087 * to/from the buffers 1088 * 1089 * REVISIT large transfers are exactly where we most want to be 1090 * using DMA. If this happens much, split those transfers into 1091 * multiple DMA segments rather than forcing PIO. 1092 */ 1093 drv_data->dma_mapped = 0; 1094 if (drv_data->len > 0 && drv_data->len <= MAX_DMA_LEN) 1095 drv_data->dma_mapped = map_dma_buffers(drv_data); 1096 if (drv_data->dma_mapped) { 1097 1098 /* Ensure we have the correct interrupt handler */ 1099 drv_data->transfer_handler = dma_transfer; 1100 1101 /* Setup rx DMA Channel */ 1102 DCSR(drv_data->rx_channel) = RESET_DMA_CHANNEL; 1103 DSADR(drv_data->rx_channel) = drv_data->ssdr_physical; 1104 DTADR(drv_data->rx_channel) = drv_data->rx_dma; 1105 if (drv_data->rx == drv_data->null_dma_buf) 1106 /* No target address increment */ 1107 DCMD(drv_data->rx_channel) = DCMD_FLOWSRC 1108 | drv_data->dma_width 1109 | dma_burst 1110 | drv_data->len; 1111 else 1112 DCMD(drv_data->rx_channel) = DCMD_INCTRGADDR 1113 | DCMD_FLOWSRC 1114 | drv_data->dma_width 1115 | dma_burst 1116 | drv_data->len; 1117 1118 /* Setup tx DMA Channel */ 1119 DCSR(drv_data->tx_channel) = RESET_DMA_CHANNEL; 1120 DSADR(drv_data->tx_channel) = drv_data->tx_dma; 1121 DTADR(drv_data->tx_channel) = drv_data->ssdr_physical; 1122 if (drv_data->tx == drv_data->null_dma_buf) 1123 /* No source address increment */ 1124 DCMD(drv_data->tx_channel) = DCMD_FLOWTRG 1125 | drv_data->dma_width 1126 | dma_burst 1127 | drv_data->len; 1128 else 1129 DCMD(drv_data->tx_channel) = DCMD_INCSRCADDR 1130 | DCMD_FLOWTRG 1131 | drv_data->dma_width 1132 | dma_burst 1133 | drv_data->len; 1134 1135 /* Enable dma end irqs on SSP to detect end of transfer */ 1136 if (drv_data->ssp_type == PXA25x_SSP) 1137 DCMD(drv_data->tx_channel) |= DCMD_ENDIRQEN; 1138 1139 /* Clear status and start DMA engine */ 1140 cr1 = chip->cr1 | dma_thresh | drv_data->dma_cr1; 1141 write_SSSR(drv_data->clear_sr, reg); 1142 DCSR(drv_data->rx_channel) |= DCSR_RUN; 1143 DCSR(drv_data->tx_channel) |= DCSR_RUN; 1144 } else { 1145 /* Ensure we have the correct interrupt handler */ 1146 drv_data->transfer_handler = interrupt_transfer; 1147 1148 /* Clear status */ 1149 cr1 = chip->cr1 | chip->threshold | drv_data->int_cr1; 1150 write_SSSR_CS(drv_data, drv_data->clear_sr); 1151 } 1152 1153 /* see if we need to reload the config registers */ 1154 if ((read_SSCR0(reg) != cr0) 1155 || (read_SSCR1(reg) & SSCR1_CHANGE_MASK) != 1156 (cr1 & SSCR1_CHANGE_MASK)) { 1157 1158 /* stop the SSP, and update the other bits */ 1159 write_SSCR0(cr0 & ~SSCR0_SSE, reg); 1160 if (!pxa25x_ssp_comp(drv_data)) 1161 write_SSTO(chip->timeout, reg); 1162 /* first set CR1 without interrupt and service enables */ 1163 write_SSCR1(cr1 & SSCR1_CHANGE_MASK, reg); 1164 /* restart the SSP */ 1165 write_SSCR0(cr0, reg); 1166 1167 } else { 1168 if (!pxa25x_ssp_comp(drv_data)) 1169 write_SSTO(chip->timeout, reg); 1170 } 1171 1172 cs_assert(drv_data); 1173 1174 /* after chip select, release the data by enabling service 1175 * requests and interrupts, without changing any mode bits */ 1176 write_SSCR1(cr1, reg); 1177 } 1178 1179 static void pump_messages(struct work_struct *work) 1180 { 1181 struct driver_data *drv_data = 1182 container_of(work, struct driver_data, pump_messages); 1183 unsigned long flags; 1184 1185 /* Lock queue and check for queue work */ 1186 spin_lock_irqsave(&drv_data->lock, flags); 1187 if (list_empty(&drv_data->queue) || drv_data->run == QUEUE_STOPPED) { 1188 drv_data->busy = 0; 1189 spin_unlock_irqrestore(&drv_data->lock, flags); 1190 return; 1191 } 1192 1193 /* Make sure we are not already running a message */ 1194 if (drv_data->cur_msg) { 1195 spin_unlock_irqrestore(&drv_data->lock, flags); 1196 return; 1197 } 1198 1199 /* Extract head of queue */ 1200 drv_data->cur_msg = list_entry(drv_data->queue.next, 1201 struct spi_message, queue); 1202 list_del_init(&drv_data->cur_msg->queue); 1203 1204 /* Initial message state*/ 1205 drv_data->cur_msg->state = START_STATE; 1206 drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next, 1207 struct spi_transfer, 1208 transfer_list); 1209 1210 /* prepare to setup the SSP, in pump_transfers, using the per 1211 * chip configuration */ 1212 drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi); 1213 1214 /* Mark as busy and launch transfers */ 1215 tasklet_schedule(&drv_data->pump_transfers); 1216 1217 drv_data->busy = 1; 1218 spin_unlock_irqrestore(&drv_data->lock, flags); 1219 } 1220 1221 static int transfer(struct spi_device *spi, struct spi_message *msg) 1222 { 1223 struct driver_data *drv_data = spi_master_get_devdata(spi->master); 1224 unsigned long flags; 1225 1226 spin_lock_irqsave(&drv_data->lock, flags); 1227 1228 if (drv_data->run == QUEUE_STOPPED) { 1229 spin_unlock_irqrestore(&drv_data->lock, flags); 1230 return -ESHUTDOWN; 1231 } 1232 1233 msg->actual_length = 0; 1234 msg->status = -EINPROGRESS; 1235 msg->state = START_STATE; 1236 1237 list_add_tail(&msg->queue, &drv_data->queue); 1238 1239 if (drv_data->run == QUEUE_RUNNING && !drv_data->busy) 1240 queue_work(drv_data->workqueue, &drv_data->pump_messages); 1241 1242 spin_unlock_irqrestore(&drv_data->lock, flags); 1243 1244 return 0; 1245 } 1246 1247 static int setup_cs(struct spi_device *spi, struct chip_data *chip, 1248 struct pxa2xx_spi_chip *chip_info) 1249 { 1250 int err = 0; 1251 1252 if (chip == NULL || chip_info == NULL) 1253 return 0; 1254 1255 /* NOTE: setup() can be called multiple times, possibly with 1256 * different chip_info, release previously requested GPIO 1257 */ 1258 if (gpio_is_valid(chip->gpio_cs)) 1259 gpio_free(chip->gpio_cs); 1260 1261 /* If (*cs_control) is provided, ignore GPIO chip select */ 1262 if (chip_info->cs_control) { 1263 chip->cs_control = chip_info->cs_control; 1264 return 0; 1265 } 1266 1267 if (gpio_is_valid(chip_info->gpio_cs)) { 1268 err = gpio_request(chip_info->gpio_cs, "SPI_CS"); 1269 if (err) { 1270 dev_err(&spi->dev, "failed to request chip select " 1271 "GPIO%d\n", chip_info->gpio_cs); 1272 return err; 1273 } 1274 1275 chip->gpio_cs = chip_info->gpio_cs; 1276 chip->gpio_cs_inverted = spi->mode & SPI_CS_HIGH; 1277 1278 err = gpio_direction_output(chip->gpio_cs, 1279 !chip->gpio_cs_inverted); 1280 } 1281 1282 return err; 1283 } 1284 1285 static int setup(struct spi_device *spi) 1286 { 1287 struct pxa2xx_spi_chip *chip_info = NULL; 1288 struct chip_data *chip; 1289 struct driver_data *drv_data = spi_master_get_devdata(spi->master); 1290 struct ssp_device *ssp = drv_data->ssp; 1291 unsigned int clk_div; 1292 uint tx_thres = TX_THRESH_DFLT; 1293 uint rx_thres = RX_THRESH_DFLT; 1294 1295 if (!pxa25x_ssp_comp(drv_data) 1296 && (spi->bits_per_word < 4 || spi->bits_per_word > 32)) { 1297 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d " 1298 "b/w not 4-32 for type non-PXA25x_SSP\n", 1299 drv_data->ssp_type, spi->bits_per_word); 1300 return -EINVAL; 1301 } else if (pxa25x_ssp_comp(drv_data) 1302 && (spi->bits_per_word < 4 1303 || spi->bits_per_word > 16)) { 1304 dev_err(&spi->dev, "failed setup: ssp_type=%d, bits/wrd=%d " 1305 "b/w not 4-16 for type PXA25x_SSP\n", 1306 drv_data->ssp_type, spi->bits_per_word); 1307 return -EINVAL; 1308 } 1309 1310 /* Only alloc on first setup */ 1311 chip = spi_get_ctldata(spi); 1312 if (!chip) { 1313 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); 1314 if (!chip) { 1315 dev_err(&spi->dev, 1316 "failed setup: can't allocate chip data\n"); 1317 return -ENOMEM; 1318 } 1319 1320 if (drv_data->ssp_type == CE4100_SSP) { 1321 if (spi->chip_select > 4) { 1322 dev_err(&spi->dev, "failed setup: " 1323 "cs number must not be > 4.\n"); 1324 kfree(chip); 1325 return -EINVAL; 1326 } 1327 1328 chip->frm = spi->chip_select; 1329 } else 1330 chip->gpio_cs = -1; 1331 chip->enable_dma = 0; 1332 chip->timeout = TIMOUT_DFLT; 1333 chip->dma_burst_size = drv_data->master_info->enable_dma ? 1334 DCMD_BURST8 : 0; 1335 } 1336 1337 /* protocol drivers may change the chip settings, so... 1338 * if chip_info exists, use it */ 1339 chip_info = spi->controller_data; 1340 1341 /* chip_info isn't always needed */ 1342 chip->cr1 = 0; 1343 if (chip_info) { 1344 if (chip_info->timeout) 1345 chip->timeout = chip_info->timeout; 1346 if (chip_info->tx_threshold) 1347 tx_thres = chip_info->tx_threshold; 1348 if (chip_info->rx_threshold) 1349 rx_thres = chip_info->rx_threshold; 1350 chip->enable_dma = drv_data->master_info->enable_dma; 1351 chip->dma_threshold = 0; 1352 if (chip_info->enable_loopback) 1353 chip->cr1 = SSCR1_LBM; 1354 } 1355 1356 chip->threshold = (SSCR1_RxTresh(rx_thres) & SSCR1_RFT) | 1357 (SSCR1_TxTresh(tx_thres) & SSCR1_TFT); 1358 1359 /* set dma burst and threshold outside of chip_info path so that if 1360 * chip_info goes away after setting chip->enable_dma, the 1361 * burst and threshold can still respond to changes in bits_per_word */ 1362 if (chip->enable_dma) { 1363 /* set up legal burst and threshold for dma */ 1364 if (set_dma_burst_and_threshold(chip, spi, spi->bits_per_word, 1365 &chip->dma_burst_size, 1366 &chip->dma_threshold)) { 1367 dev_warn(&spi->dev, "in setup: DMA burst size reduced " 1368 "to match bits_per_word\n"); 1369 } 1370 } 1371 1372 clk_div = ssp_get_clk_div(ssp, spi->max_speed_hz); 1373 chip->speed_hz = spi->max_speed_hz; 1374 1375 chip->cr0 = clk_div 1376 | SSCR0_Motorola 1377 | SSCR0_DataSize(spi->bits_per_word > 16 ? 1378 spi->bits_per_word - 16 : spi->bits_per_word) 1379 | SSCR0_SSE 1380 | (spi->bits_per_word > 16 ? SSCR0_EDSS : 0); 1381 chip->cr1 &= ~(SSCR1_SPO | SSCR1_SPH); 1382 chip->cr1 |= (((spi->mode & SPI_CPHA) != 0) ? SSCR1_SPH : 0) 1383 | (((spi->mode & SPI_CPOL) != 0) ? SSCR1_SPO : 0); 1384 1385 /* NOTE: PXA25x_SSP _could_ use external clocking ... */ 1386 if (!pxa25x_ssp_comp(drv_data)) 1387 dev_dbg(&spi->dev, "%ld Hz actual, %s\n", 1388 clk_get_rate(ssp->clk) 1389 / (1 + ((chip->cr0 & SSCR0_SCR(0xfff)) >> 8)), 1390 chip->enable_dma ? "DMA" : "PIO"); 1391 else 1392 dev_dbg(&spi->dev, "%ld Hz actual, %s\n", 1393 clk_get_rate(ssp->clk) / 2 1394 / (1 + ((chip->cr0 & SSCR0_SCR(0x0ff)) >> 8)), 1395 chip->enable_dma ? "DMA" : "PIO"); 1396 1397 if (spi->bits_per_word <= 8) { 1398 chip->n_bytes = 1; 1399 chip->dma_width = DCMD_WIDTH1; 1400 chip->read = u8_reader; 1401 chip->write = u8_writer; 1402 } else if (spi->bits_per_word <= 16) { 1403 chip->n_bytes = 2; 1404 chip->dma_width = DCMD_WIDTH2; 1405 chip->read = u16_reader; 1406 chip->write = u16_writer; 1407 } else if (spi->bits_per_word <= 32) { 1408 chip->cr0 |= SSCR0_EDSS; 1409 chip->n_bytes = 4; 1410 chip->dma_width = DCMD_WIDTH4; 1411 chip->read = u32_reader; 1412 chip->write = u32_writer; 1413 } else { 1414 dev_err(&spi->dev, "invalid wordsize\n"); 1415 return -ENODEV; 1416 } 1417 chip->bits_per_word = spi->bits_per_word; 1418 1419 spi_set_ctldata(spi, chip); 1420 1421 if (drv_data->ssp_type == CE4100_SSP) 1422 return 0; 1423 1424 return setup_cs(spi, chip, chip_info); 1425 } 1426 1427 static void cleanup(struct spi_device *spi) 1428 { 1429 struct chip_data *chip = spi_get_ctldata(spi); 1430 struct driver_data *drv_data = spi_master_get_devdata(spi->master); 1431 1432 if (!chip) 1433 return; 1434 1435 if (drv_data->ssp_type != CE4100_SSP && gpio_is_valid(chip->gpio_cs)) 1436 gpio_free(chip->gpio_cs); 1437 1438 kfree(chip); 1439 } 1440 1441 static int init_queue(struct driver_data *drv_data) 1442 { 1443 INIT_LIST_HEAD(&drv_data->queue); 1444 spin_lock_init(&drv_data->lock); 1445 1446 drv_data->run = QUEUE_STOPPED; 1447 drv_data->busy = 0; 1448 1449 tasklet_init(&drv_data->pump_transfers, 1450 pump_transfers, (unsigned long)drv_data); 1451 1452 INIT_WORK(&drv_data->pump_messages, pump_messages); 1453 drv_data->workqueue = create_singlethread_workqueue( 1454 dev_name(drv_data->master->dev.parent)); 1455 if (drv_data->workqueue == NULL) 1456 return -EBUSY; 1457 1458 return 0; 1459 } 1460 1461 static int start_queue(struct driver_data *drv_data) 1462 { 1463 unsigned long flags; 1464 1465 spin_lock_irqsave(&drv_data->lock, flags); 1466 1467 if (drv_data->run == QUEUE_RUNNING || drv_data->busy) { 1468 spin_unlock_irqrestore(&drv_data->lock, flags); 1469 return -EBUSY; 1470 } 1471 1472 drv_data->run = QUEUE_RUNNING; 1473 drv_data->cur_msg = NULL; 1474 drv_data->cur_transfer = NULL; 1475 drv_data->cur_chip = NULL; 1476 spin_unlock_irqrestore(&drv_data->lock, flags); 1477 1478 queue_work(drv_data->workqueue, &drv_data->pump_messages); 1479 1480 return 0; 1481 } 1482 1483 static int stop_queue(struct driver_data *drv_data) 1484 { 1485 unsigned long flags; 1486 unsigned limit = 500; 1487 int status = 0; 1488 1489 spin_lock_irqsave(&drv_data->lock, flags); 1490 1491 /* This is a bit lame, but is optimized for the common execution path. 1492 * A wait_queue on the drv_data->busy could be used, but then the common 1493 * execution path (pump_messages) would be required to call wake_up or 1494 * friends on every SPI message. Do this instead */ 1495 drv_data->run = QUEUE_STOPPED; 1496 while ((!list_empty(&drv_data->queue) || drv_data->busy) && limit--) { 1497 spin_unlock_irqrestore(&drv_data->lock, flags); 1498 msleep(10); 1499 spin_lock_irqsave(&drv_data->lock, flags); 1500 } 1501 1502 if (!list_empty(&drv_data->queue) || drv_data->busy) 1503 status = -EBUSY; 1504 1505 spin_unlock_irqrestore(&drv_data->lock, flags); 1506 1507 return status; 1508 } 1509 1510 static int destroy_queue(struct driver_data *drv_data) 1511 { 1512 int status; 1513 1514 status = stop_queue(drv_data); 1515 /* we are unloading the module or failing to load (only two calls 1516 * to this routine), and neither call can handle a return value. 1517 * However, destroy_workqueue calls flush_workqueue, and that will 1518 * block until all work is done. If the reason that stop_queue 1519 * timed out is that the work will never finish, then it does no 1520 * good to call destroy_workqueue, so return anyway. */ 1521 if (status != 0) 1522 return status; 1523 1524 destroy_workqueue(drv_data->workqueue); 1525 1526 return 0; 1527 } 1528 1529 static int pxa2xx_spi_probe(struct platform_device *pdev) 1530 { 1531 struct device *dev = &pdev->dev; 1532 struct pxa2xx_spi_master *platform_info; 1533 struct spi_master *master; 1534 struct driver_data *drv_data; 1535 struct ssp_device *ssp; 1536 int status; 1537 1538 platform_info = dev->platform_data; 1539 1540 ssp = pxa_ssp_request(pdev->id, pdev->name); 1541 if (ssp == NULL) { 1542 dev_err(&pdev->dev, "failed to request SSP%d\n", pdev->id); 1543 return -ENODEV; 1544 } 1545 1546 /* Allocate master with space for drv_data and null dma buffer */ 1547 master = spi_alloc_master(dev, sizeof(struct driver_data) + 16); 1548 if (!master) { 1549 dev_err(&pdev->dev, "cannot alloc spi_master\n"); 1550 pxa_ssp_free(ssp); 1551 return -ENOMEM; 1552 } 1553 drv_data = spi_master_get_devdata(master); 1554 drv_data->master = master; 1555 drv_data->master_info = platform_info; 1556 drv_data->pdev = pdev; 1557 drv_data->ssp = ssp; 1558 1559 master->dev.parent = &pdev->dev; 1560 master->dev.of_node = pdev->dev.of_node; 1561 /* the spi->mode bits understood by this driver: */ 1562 master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; 1563 1564 master->bus_num = pdev->id; 1565 master->num_chipselect = platform_info->num_chipselect; 1566 master->dma_alignment = DMA_ALIGNMENT; 1567 master->cleanup = cleanup; 1568 master->setup = setup; 1569 master->transfer = transfer; 1570 1571 drv_data->ssp_type = ssp->type; 1572 drv_data->null_dma_buf = (u32 *)ALIGN((u32)(drv_data + 1573 sizeof(struct driver_data)), 8); 1574 1575 drv_data->ioaddr = ssp->mmio_base; 1576 drv_data->ssdr_physical = ssp->phys_base + SSDR; 1577 if (pxa25x_ssp_comp(drv_data)) { 1578 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE; 1579 drv_data->dma_cr1 = 0; 1580 drv_data->clear_sr = SSSR_ROR; 1581 drv_data->mask_sr = SSSR_RFS | SSSR_TFS | SSSR_ROR; 1582 } else { 1583 drv_data->int_cr1 = SSCR1_TIE | SSCR1_RIE | SSCR1_TINTE; 1584 drv_data->dma_cr1 = SSCR1_TSRE | SSCR1_RSRE | SSCR1_TINTE; 1585 drv_data->clear_sr = SSSR_ROR | SSSR_TINT; 1586 drv_data->mask_sr = SSSR_TINT | SSSR_RFS | SSSR_TFS | SSSR_ROR; 1587 } 1588 1589 status = request_irq(ssp->irq, ssp_int, IRQF_SHARED, dev_name(dev), 1590 drv_data); 1591 if (status < 0) { 1592 dev_err(&pdev->dev, "cannot get IRQ %d\n", ssp->irq); 1593 goto out_error_master_alloc; 1594 } 1595 1596 /* Setup DMA if requested */ 1597 drv_data->tx_channel = -1; 1598 drv_data->rx_channel = -1; 1599 if (platform_info->enable_dma) { 1600 1601 /* Get two DMA channels (rx and tx) */ 1602 drv_data->rx_channel = pxa_request_dma("pxa2xx_spi_ssp_rx", 1603 DMA_PRIO_HIGH, 1604 dma_handler, 1605 drv_data); 1606 if (drv_data->rx_channel < 0) { 1607 dev_err(dev, "problem (%d) requesting rx channel\n", 1608 drv_data->rx_channel); 1609 status = -ENODEV; 1610 goto out_error_irq_alloc; 1611 } 1612 drv_data->tx_channel = pxa_request_dma("pxa2xx_spi_ssp_tx", 1613 DMA_PRIO_MEDIUM, 1614 dma_handler, 1615 drv_data); 1616 if (drv_data->tx_channel < 0) { 1617 dev_err(dev, "problem (%d) requesting tx channel\n", 1618 drv_data->tx_channel); 1619 status = -ENODEV; 1620 goto out_error_dma_alloc; 1621 } 1622 1623 DRCMR(ssp->drcmr_rx) = DRCMR_MAPVLD | drv_data->rx_channel; 1624 DRCMR(ssp->drcmr_tx) = DRCMR_MAPVLD | drv_data->tx_channel; 1625 } 1626 1627 /* Enable SOC clock */ 1628 clk_enable(ssp->clk); 1629 1630 /* Load default SSP configuration */ 1631 write_SSCR0(0, drv_data->ioaddr); 1632 write_SSCR1(SSCR1_RxTresh(RX_THRESH_DFLT) | 1633 SSCR1_TxTresh(TX_THRESH_DFLT), 1634 drv_data->ioaddr); 1635 write_SSCR0(SSCR0_SCR(2) 1636 | SSCR0_Motorola 1637 | SSCR0_DataSize(8), 1638 drv_data->ioaddr); 1639 if (!pxa25x_ssp_comp(drv_data)) 1640 write_SSTO(0, drv_data->ioaddr); 1641 write_SSPSP(0, drv_data->ioaddr); 1642 1643 /* Initial and start queue */ 1644 status = init_queue(drv_data); 1645 if (status != 0) { 1646 dev_err(&pdev->dev, "problem initializing queue\n"); 1647 goto out_error_clock_enabled; 1648 } 1649 status = start_queue(drv_data); 1650 if (status != 0) { 1651 dev_err(&pdev->dev, "problem starting queue\n"); 1652 goto out_error_clock_enabled; 1653 } 1654 1655 /* Register with the SPI framework */ 1656 platform_set_drvdata(pdev, drv_data); 1657 status = spi_register_master(master); 1658 if (status != 0) { 1659 dev_err(&pdev->dev, "problem registering spi master\n"); 1660 goto out_error_queue_alloc; 1661 } 1662 1663 return status; 1664 1665 out_error_queue_alloc: 1666 destroy_queue(drv_data); 1667 1668 out_error_clock_enabled: 1669 clk_disable(ssp->clk); 1670 1671 out_error_dma_alloc: 1672 if (drv_data->tx_channel != -1) 1673 pxa_free_dma(drv_data->tx_channel); 1674 if (drv_data->rx_channel != -1) 1675 pxa_free_dma(drv_data->rx_channel); 1676 1677 out_error_irq_alloc: 1678 free_irq(ssp->irq, drv_data); 1679 1680 out_error_master_alloc: 1681 spi_master_put(master); 1682 pxa_ssp_free(ssp); 1683 return status; 1684 } 1685 1686 static int pxa2xx_spi_remove(struct platform_device *pdev) 1687 { 1688 struct driver_data *drv_data = platform_get_drvdata(pdev); 1689 struct ssp_device *ssp; 1690 int status = 0; 1691 1692 if (!drv_data) 1693 return 0; 1694 ssp = drv_data->ssp; 1695 1696 /* Remove the queue */ 1697 status = destroy_queue(drv_data); 1698 if (status != 0) 1699 /* the kernel does not check the return status of this 1700 * this routine (mod->exit, within the kernel). Therefore 1701 * nothing is gained by returning from here, the module is 1702 * going away regardless, and we should not leave any more 1703 * resources allocated than necessary. We cannot free the 1704 * message memory in drv_data->queue, but we can release the 1705 * resources below. I think the kernel should honor -EBUSY 1706 * returns but... */ 1707 dev_err(&pdev->dev, "pxa2xx_spi_remove: workqueue will not " 1708 "complete, message memory not freed\n"); 1709 1710 /* Disable the SSP at the peripheral and SOC level */ 1711 write_SSCR0(0, drv_data->ioaddr); 1712 clk_disable(ssp->clk); 1713 1714 /* Release DMA */ 1715 if (drv_data->master_info->enable_dma) { 1716 DRCMR(ssp->drcmr_rx) = 0; 1717 DRCMR(ssp->drcmr_tx) = 0; 1718 pxa_free_dma(drv_data->tx_channel); 1719 pxa_free_dma(drv_data->rx_channel); 1720 } 1721 1722 /* Release IRQ */ 1723 free_irq(ssp->irq, drv_data); 1724 1725 /* Release SSP */ 1726 pxa_ssp_free(ssp); 1727 1728 /* Disconnect from the SPI framework */ 1729 spi_unregister_master(drv_data->master); 1730 1731 /* Prevent double remove */ 1732 platform_set_drvdata(pdev, NULL); 1733 1734 return 0; 1735 } 1736 1737 static void pxa2xx_spi_shutdown(struct platform_device *pdev) 1738 { 1739 int status = 0; 1740 1741 if ((status = pxa2xx_spi_remove(pdev)) != 0) 1742 dev_err(&pdev->dev, "shutdown failed with %d\n", status); 1743 } 1744 1745 #ifdef CONFIG_PM 1746 static int pxa2xx_spi_suspend(struct device *dev) 1747 { 1748 struct driver_data *drv_data = dev_get_drvdata(dev); 1749 struct ssp_device *ssp = drv_data->ssp; 1750 int status = 0; 1751 1752 status = stop_queue(drv_data); 1753 if (status != 0) 1754 return status; 1755 write_SSCR0(0, drv_data->ioaddr); 1756 clk_disable(ssp->clk); 1757 1758 return 0; 1759 } 1760 1761 static int pxa2xx_spi_resume(struct device *dev) 1762 { 1763 struct driver_data *drv_data = dev_get_drvdata(dev); 1764 struct ssp_device *ssp = drv_data->ssp; 1765 int status = 0; 1766 1767 if (drv_data->rx_channel != -1) 1768 DRCMR(drv_data->ssp->drcmr_rx) = 1769 DRCMR_MAPVLD | drv_data->rx_channel; 1770 if (drv_data->tx_channel != -1) 1771 DRCMR(drv_data->ssp->drcmr_tx) = 1772 DRCMR_MAPVLD | drv_data->tx_channel; 1773 1774 /* Enable the SSP clock */ 1775 clk_enable(ssp->clk); 1776 1777 /* Start the queue running */ 1778 status = start_queue(drv_data); 1779 if (status != 0) { 1780 dev_err(dev, "problem starting queue (%d)\n", status); 1781 return status; 1782 } 1783 1784 return 0; 1785 } 1786 1787 static const struct dev_pm_ops pxa2xx_spi_pm_ops = { 1788 .suspend = pxa2xx_spi_suspend, 1789 .resume = pxa2xx_spi_resume, 1790 }; 1791 #endif 1792 1793 static struct platform_driver driver = { 1794 .driver = { 1795 .name = "pxa2xx-spi", 1796 .owner = THIS_MODULE, 1797 #ifdef CONFIG_PM 1798 .pm = &pxa2xx_spi_pm_ops, 1799 #endif 1800 }, 1801 .probe = pxa2xx_spi_probe, 1802 .remove = pxa2xx_spi_remove, 1803 .shutdown = pxa2xx_spi_shutdown, 1804 }; 1805 1806 static int __init pxa2xx_spi_init(void) 1807 { 1808 return platform_driver_register(&driver); 1809 } 1810 subsys_initcall(pxa2xx_spi_init); 1811 1812 static void __exit pxa2xx_spi_exit(void) 1813 { 1814 platform_driver_unregister(&driver); 1815 } 1816 module_exit(pxa2xx_spi_exit); 1817