bfin_can.c revision cfbf7586bc07cd6d14cd93ca56d8a3f90e248625
1/* 2 * Blackfin On-Chip CAN Driver 3 * 4 * Copyright 2004-2009 Analog Devices Inc. 5 * 6 * Enter bugs at http://blackfin.uclinux.org/ 7 * 8 * Licensed under the GPL-2 or later. 9 */ 10 11#include <linux/module.h> 12#include <linux/init.h> 13#include <linux/kernel.h> 14#include <linux/bitops.h> 15#include <linux/interrupt.h> 16#include <linux/errno.h> 17#include <linux/netdevice.h> 18#include <linux/skbuff.h> 19#include <linux/platform_device.h> 20 21#include <linux/can/dev.h> 22#include <linux/can/error.h> 23 24#include <asm/bfin_can.h> 25#include <asm/portmux.h> 26 27#define DRV_NAME "bfin_can" 28#define BFIN_CAN_TIMEOUT 100 29#define TX_ECHO_SKB_MAX 1 30 31/* 32 * bfin can private data 33 */ 34struct bfin_can_priv { 35 struct can_priv can; /* must be the first member */ 36 struct net_device *dev; 37 void __iomem *membase; 38 int rx_irq; 39 int tx_irq; 40 int err_irq; 41 unsigned short *pin_list; 42}; 43 44/* 45 * bfin can timing parameters 46 */ 47static struct can_bittiming_const bfin_can_bittiming_const = { 48 .name = DRV_NAME, 49 .tseg1_min = 1, 50 .tseg1_max = 16, 51 .tseg2_min = 1, 52 .tseg2_max = 8, 53 .sjw_max = 4, 54 /* 55 * Although the BRP field can be set to any value, it is recommended 56 * that the value be greater than or equal to 4, as restrictions 57 * apply to the bit timing configuration when BRP is less than 4. 58 */ 59 .brp_min = 4, 60 .brp_max = 1024, 61 .brp_inc = 1, 62}; 63 64static int bfin_can_set_bittiming(struct net_device *dev) 65{ 66 struct bfin_can_priv *priv = netdev_priv(dev); 67 struct bfin_can_regs __iomem *reg = priv->membase; 68 struct can_bittiming *bt = &priv->can.bittiming; 69 u16 clk, timing; 70 71 clk = bt->brp - 1; 72 timing = ((bt->sjw - 1) << 8) | (bt->prop_seg + bt->phase_seg1 - 1) | 73 ((bt->phase_seg2 - 1) << 4); 74 75 /* 76 * If the SAM bit is set, the input signal is oversampled three times 77 * at the SCLK rate. 78 */ 79 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 80 timing |= SAM; 81 82 bfin_write(®->clock, clk); 83 bfin_write(®->timing, timing); 84 85 dev_info(dev->dev.parent, "setting CLOCK=0x%04x TIMING=0x%04x\n", 86 clk, timing); 87 88 return 0; 89} 90 91static void bfin_can_set_reset_mode(struct net_device *dev) 92{ 93 struct bfin_can_priv *priv = netdev_priv(dev); 94 struct bfin_can_regs __iomem *reg = priv->membase; 95 int timeout = BFIN_CAN_TIMEOUT; 96 int i; 97 98 /* disable interrupts */ 99 bfin_write(®->mbim1, 0); 100 bfin_write(®->mbim2, 0); 101 bfin_write(®->gim, 0); 102 103 /* reset can and enter configuration mode */ 104 bfin_write(®->control, SRS | CCR); 105 SSYNC(); 106 bfin_write(®->control, CCR); 107 SSYNC(); 108 while (!(bfin_read(®->control) & CCA)) { 109 udelay(10); 110 if (--timeout == 0) { 111 dev_err(dev->dev.parent, 112 "fail to enter configuration mode\n"); 113 BUG(); 114 } 115 } 116 117 /* 118 * All mailbox configurations are marked as inactive 119 * by writing to CAN Mailbox Configuration Registers 1 and 2 120 * For all bits: 0 - Mailbox disabled, 1 - Mailbox enabled 121 */ 122 bfin_write(®->mc1, 0); 123 bfin_write(®->mc2, 0); 124 125 /* Set Mailbox Direction */ 126 bfin_write(®->md1, 0xFFFF); /* mailbox 1-16 are RX */ 127 bfin_write(®->md2, 0); /* mailbox 17-32 are TX */ 128 129 /* RECEIVE_STD_CHL */ 130 for (i = 0; i < 2; i++) { 131 bfin_write(®->chl[RECEIVE_STD_CHL + i].id0, 0); 132 bfin_write(®->chl[RECEIVE_STD_CHL + i].id1, AME); 133 bfin_write(®->chl[RECEIVE_STD_CHL + i].dlc, 0); 134 bfin_write(®->msk[RECEIVE_STD_CHL + i].amh, 0x1FFF); 135 bfin_write(®->msk[RECEIVE_STD_CHL + i].aml, 0xFFFF); 136 } 137 138 /* RECEIVE_EXT_CHL */ 139 for (i = 0; i < 2; i++) { 140 bfin_write(®->chl[RECEIVE_EXT_CHL + i].id0, 0); 141 bfin_write(®->chl[RECEIVE_EXT_CHL + i].id1, AME | IDE); 142 bfin_write(®->chl[RECEIVE_EXT_CHL + i].dlc, 0); 143 bfin_write(®->msk[RECEIVE_EXT_CHL + i].amh, 0x1FFF); 144 bfin_write(®->msk[RECEIVE_EXT_CHL + i].aml, 0xFFFF); 145 } 146 147 bfin_write(®->mc2, BIT(TRANSMIT_CHL - 16)); 148 bfin_write(®->mc1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL)); 149 SSYNC(); 150 151 priv->can.state = CAN_STATE_STOPPED; 152} 153 154static void bfin_can_set_normal_mode(struct net_device *dev) 155{ 156 struct bfin_can_priv *priv = netdev_priv(dev); 157 struct bfin_can_regs __iomem *reg = priv->membase; 158 int timeout = BFIN_CAN_TIMEOUT; 159 160 /* 161 * leave configuration mode 162 */ 163 bfin_write(®->control, bfin_read(®->control) & ~CCR); 164 165 while (bfin_read(®->status) & CCA) { 166 udelay(10); 167 if (--timeout == 0) { 168 dev_err(dev->dev.parent, 169 "fail to leave configuration mode\n"); 170 BUG(); 171 } 172 } 173 174 /* 175 * clear _All_ tx and rx interrupts 176 */ 177 bfin_write(®->mbtif1, 0xFFFF); 178 bfin_write(®->mbtif2, 0xFFFF); 179 bfin_write(®->mbrif1, 0xFFFF); 180 bfin_write(®->mbrif2, 0xFFFF); 181 182 /* 183 * clear global interrupt status register 184 */ 185 bfin_write(®->gis, 0x7FF); /* overwrites with '1' */ 186 187 /* 188 * Initialize Interrupts 189 * - set bits in the mailbox interrupt mask register 190 * - global interrupt mask 191 */ 192 bfin_write(®->mbim1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL)); 193 bfin_write(®->mbim2, BIT(TRANSMIT_CHL - 16)); 194 195 bfin_write(®->gim, EPIM | BOIM | RMLIM); 196 SSYNC(); 197} 198 199static void bfin_can_start(struct net_device *dev) 200{ 201 struct bfin_can_priv *priv = netdev_priv(dev); 202 203 /* enter reset mode */ 204 if (priv->can.state != CAN_STATE_STOPPED) 205 bfin_can_set_reset_mode(dev); 206 207 /* leave reset mode */ 208 bfin_can_set_normal_mode(dev); 209} 210 211static int bfin_can_set_mode(struct net_device *dev, enum can_mode mode) 212{ 213 switch (mode) { 214 case CAN_MODE_START: 215 bfin_can_start(dev); 216 if (netif_queue_stopped(dev)) 217 netif_wake_queue(dev); 218 break; 219 220 default: 221 return -EOPNOTSUPP; 222 } 223 224 return 0; 225} 226 227static int bfin_can_start_xmit(struct sk_buff *skb, struct net_device *dev) 228{ 229 struct bfin_can_priv *priv = netdev_priv(dev); 230 struct bfin_can_regs __iomem *reg = priv->membase; 231 struct can_frame *cf = (struct can_frame *)skb->data; 232 u8 dlc = cf->can_dlc; 233 canid_t id = cf->can_id; 234 u8 *data = cf->data; 235 u16 val; 236 int i; 237 238 if (can_dropped_invalid_skb(dev, skb)) 239 return NETDEV_TX_OK; 240 241 netif_stop_queue(dev); 242 243 /* fill id */ 244 if (id & CAN_EFF_FLAG) { 245 bfin_write(®->chl[TRANSMIT_CHL].id0, id); 246 val = ((id & 0x1FFF0000) >> 16) | IDE; 247 } else 248 val = (id << 2); 249 if (id & CAN_RTR_FLAG) 250 val |= RTR; 251 bfin_write(®->chl[TRANSMIT_CHL].id1, val | AME); 252 253 /* fill payload */ 254 for (i = 0; i < 8; i += 2) { 255 val = ((7 - i) < dlc ? (data[7 - i]) : 0) + 256 ((6 - i) < dlc ? (data[6 - i] << 8) : 0); 257 bfin_write(®->chl[TRANSMIT_CHL].data[i], val); 258 } 259 260 /* fill data length code */ 261 bfin_write(®->chl[TRANSMIT_CHL].dlc, dlc); 262 263 can_put_echo_skb(skb, dev, 0); 264 265 /* set transmit request */ 266 bfin_write(®->trs2, BIT(TRANSMIT_CHL - 16)); 267 268 return 0; 269} 270 271static void bfin_can_rx(struct net_device *dev, u16 isrc) 272{ 273 struct bfin_can_priv *priv = netdev_priv(dev); 274 struct net_device_stats *stats = &dev->stats; 275 struct bfin_can_regs __iomem *reg = priv->membase; 276 struct can_frame *cf; 277 struct sk_buff *skb; 278 int obj; 279 int i; 280 u16 val; 281 282 skb = alloc_can_skb(dev, &cf); 283 if (skb == NULL) 284 return; 285 286 /* get id */ 287 if (isrc & BIT(RECEIVE_EXT_CHL)) { 288 /* extended frame format (EFF) */ 289 cf->can_id = ((bfin_read(®->chl[RECEIVE_EXT_CHL].id1) 290 & 0x1FFF) << 16) 291 + bfin_read(®->chl[RECEIVE_EXT_CHL].id0); 292 cf->can_id |= CAN_EFF_FLAG; 293 obj = RECEIVE_EXT_CHL; 294 } else { 295 /* standard frame format (SFF) */ 296 cf->can_id = (bfin_read(®->chl[RECEIVE_STD_CHL].id1) 297 & 0x1ffc) >> 2; 298 obj = RECEIVE_STD_CHL; 299 } 300 if (bfin_read(®->chl[obj].id1) & RTR) 301 cf->can_id |= CAN_RTR_FLAG; 302 303 /* get data length code */ 304 cf->can_dlc = get_can_dlc(bfin_read(®->chl[obj].dlc) & 0xF); 305 306 /* get payload */ 307 for (i = 0; i < 8; i += 2) { 308 val = bfin_read(®->chl[obj].data[i]); 309 cf->data[7 - i] = (7 - i) < cf->can_dlc ? val : 0; 310 cf->data[6 - i] = (6 - i) < cf->can_dlc ? (val >> 8) : 0; 311 } 312 313 netif_rx(skb); 314 315 stats->rx_packets++; 316 stats->rx_bytes += cf->can_dlc; 317} 318 319static int bfin_can_err(struct net_device *dev, u16 isrc, u16 status) 320{ 321 struct bfin_can_priv *priv = netdev_priv(dev); 322 struct bfin_can_regs __iomem *reg = priv->membase; 323 struct net_device_stats *stats = &dev->stats; 324 struct can_frame *cf; 325 struct sk_buff *skb; 326 enum can_state state = priv->can.state; 327 328 skb = alloc_can_err_skb(dev, &cf); 329 if (skb == NULL) 330 return -ENOMEM; 331 332 if (isrc & RMLIS) { 333 /* data overrun interrupt */ 334 dev_dbg(dev->dev.parent, "data overrun interrupt\n"); 335 cf->can_id |= CAN_ERR_CRTL; 336 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 337 stats->rx_over_errors++; 338 stats->rx_errors++; 339 } 340 341 if (isrc & BOIS) { 342 dev_dbg(dev->dev.parent, "bus-off mode interrupt\n"); 343 state = CAN_STATE_BUS_OFF; 344 cf->can_id |= CAN_ERR_BUSOFF; 345 can_bus_off(dev); 346 } 347 348 if (isrc & EPIS) { 349 /* error passive interrupt */ 350 dev_dbg(dev->dev.parent, "error passive interrupt\n"); 351 state = CAN_STATE_ERROR_PASSIVE; 352 } 353 354 if ((isrc & EWTIS) || (isrc & EWRIS)) { 355 dev_dbg(dev->dev.parent, 356 "Error Warning Transmit/Receive Interrupt\n"); 357 state = CAN_STATE_ERROR_WARNING; 358 } 359 360 if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING || 361 state == CAN_STATE_ERROR_PASSIVE)) { 362 u16 cec = bfin_read(®->cec); 363 u8 rxerr = cec; 364 u8 txerr = cec >> 8; 365 366 cf->can_id |= CAN_ERR_CRTL; 367 if (state == CAN_STATE_ERROR_WARNING) { 368 priv->can.can_stats.error_warning++; 369 cf->data[1] = (txerr > rxerr) ? 370 CAN_ERR_CRTL_TX_WARNING : 371 CAN_ERR_CRTL_RX_WARNING; 372 } else { 373 priv->can.can_stats.error_passive++; 374 cf->data[1] = (txerr > rxerr) ? 375 CAN_ERR_CRTL_TX_PASSIVE : 376 CAN_ERR_CRTL_RX_PASSIVE; 377 } 378 } 379 380 if (status) { 381 priv->can.can_stats.bus_error++; 382 383 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 384 385 if (status & BEF) 386 cf->data[2] |= CAN_ERR_PROT_BIT; 387 else if (status & FER) 388 cf->data[2] |= CAN_ERR_PROT_FORM; 389 else if (status & SER) 390 cf->data[2] |= CAN_ERR_PROT_STUFF; 391 else 392 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 393 } 394 395 priv->can.state = state; 396 397 netif_rx(skb); 398 399 stats->rx_packets++; 400 stats->rx_bytes += cf->can_dlc; 401 402 return 0; 403} 404 405irqreturn_t bfin_can_interrupt(int irq, void *dev_id) 406{ 407 struct net_device *dev = dev_id; 408 struct bfin_can_priv *priv = netdev_priv(dev); 409 struct bfin_can_regs __iomem *reg = priv->membase; 410 struct net_device_stats *stats = &dev->stats; 411 u16 status, isrc; 412 413 if ((irq == priv->tx_irq) && bfin_read(®->mbtif2)) { 414 /* transmission complete interrupt */ 415 bfin_write(®->mbtif2, 0xFFFF); 416 stats->tx_packets++; 417 stats->tx_bytes += bfin_read(®->chl[TRANSMIT_CHL].dlc); 418 can_get_echo_skb(dev, 0); 419 netif_wake_queue(dev); 420 } else if ((irq == priv->rx_irq) && bfin_read(®->mbrif1)) { 421 /* receive interrupt */ 422 isrc = bfin_read(®->mbrif1); 423 bfin_write(®->mbrif1, 0xFFFF); 424 bfin_can_rx(dev, isrc); 425 } else if ((irq == priv->err_irq) && bfin_read(®->gis)) { 426 /* error interrupt */ 427 isrc = bfin_read(®->gis); 428 status = bfin_read(®->esr); 429 bfin_write(®->gis, 0x7FF); 430 bfin_can_err(dev, isrc, status); 431 } else { 432 return IRQ_NONE; 433 } 434 435 return IRQ_HANDLED; 436} 437 438static int bfin_can_open(struct net_device *dev) 439{ 440 struct bfin_can_priv *priv = netdev_priv(dev); 441 int err; 442 443 /* set chip into reset mode */ 444 bfin_can_set_reset_mode(dev); 445 446 /* common open */ 447 err = open_candev(dev); 448 if (err) 449 goto exit_open; 450 451 /* register interrupt handler */ 452 err = request_irq(priv->rx_irq, &bfin_can_interrupt, 0, 453 "bfin-can-rx", dev); 454 if (err) 455 goto exit_rx_irq; 456 err = request_irq(priv->tx_irq, &bfin_can_interrupt, 0, 457 "bfin-can-tx", dev); 458 if (err) 459 goto exit_tx_irq; 460 err = request_irq(priv->err_irq, &bfin_can_interrupt, 0, 461 "bfin-can-err", dev); 462 if (err) 463 goto exit_err_irq; 464 465 bfin_can_start(dev); 466 467 netif_start_queue(dev); 468 469 return 0; 470 471exit_err_irq: 472 free_irq(priv->tx_irq, dev); 473exit_tx_irq: 474 free_irq(priv->rx_irq, dev); 475exit_rx_irq: 476 close_candev(dev); 477exit_open: 478 return err; 479} 480 481static int bfin_can_close(struct net_device *dev) 482{ 483 struct bfin_can_priv *priv = netdev_priv(dev); 484 485 netif_stop_queue(dev); 486 bfin_can_set_reset_mode(dev); 487 488 close_candev(dev); 489 490 free_irq(priv->rx_irq, dev); 491 free_irq(priv->tx_irq, dev); 492 free_irq(priv->err_irq, dev); 493 494 return 0; 495} 496 497struct net_device *alloc_bfin_candev(void) 498{ 499 struct net_device *dev; 500 struct bfin_can_priv *priv; 501 502 dev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX); 503 if (!dev) 504 return NULL; 505 506 priv = netdev_priv(dev); 507 508 priv->dev = dev; 509 priv->can.bittiming_const = &bfin_can_bittiming_const; 510 priv->can.do_set_bittiming = bfin_can_set_bittiming; 511 priv->can.do_set_mode = bfin_can_set_mode; 512 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 513 514 return dev; 515} 516 517static const struct net_device_ops bfin_can_netdev_ops = { 518 .ndo_open = bfin_can_open, 519 .ndo_stop = bfin_can_close, 520 .ndo_start_xmit = bfin_can_start_xmit, 521}; 522 523static int __devinit bfin_can_probe(struct platform_device *pdev) 524{ 525 int err; 526 struct net_device *dev; 527 struct bfin_can_priv *priv; 528 struct resource *res_mem, *rx_irq, *tx_irq, *err_irq; 529 unsigned short *pdata; 530 531 pdata = pdev->dev.platform_data; 532 if (!pdata) { 533 dev_err(&pdev->dev, "No platform data provided!\n"); 534 err = -EINVAL; 535 goto exit; 536 } 537 538 res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 539 rx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 540 tx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 1); 541 err_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 2); 542 if (!res_mem || !rx_irq || !tx_irq || !err_irq) { 543 err = -EINVAL; 544 goto exit; 545 } 546 547 if (!request_mem_region(res_mem->start, resource_size(res_mem), 548 dev_name(&pdev->dev))) { 549 err = -EBUSY; 550 goto exit; 551 } 552 553 /* request peripheral pins */ 554 err = peripheral_request_list(pdata, dev_name(&pdev->dev)); 555 if (err) 556 goto exit_mem_release; 557 558 dev = alloc_bfin_candev(); 559 if (!dev) { 560 err = -ENOMEM; 561 goto exit_peri_pin_free; 562 } 563 564 priv = netdev_priv(dev); 565 priv->membase = (void __iomem *)res_mem->start; 566 priv->rx_irq = rx_irq->start; 567 priv->tx_irq = tx_irq->start; 568 priv->err_irq = err_irq->start; 569 priv->pin_list = pdata; 570 priv->can.clock.freq = get_sclk(); 571 572 dev_set_drvdata(&pdev->dev, dev); 573 SET_NETDEV_DEV(dev, &pdev->dev); 574 575 dev->flags |= IFF_ECHO; /* we support local echo */ 576 dev->netdev_ops = &bfin_can_netdev_ops; 577 578 bfin_can_set_reset_mode(dev); 579 580 err = register_candev(dev); 581 if (err) { 582 dev_err(&pdev->dev, "registering failed (err=%d)\n", err); 583 goto exit_candev_free; 584 } 585 586 dev_info(&pdev->dev, 587 "%s device registered" 588 "(®_base=%p, rx_irq=%d, tx_irq=%d, err_irq=%d, sclk=%d)\n", 589 DRV_NAME, (void *)priv->membase, priv->rx_irq, 590 priv->tx_irq, priv->err_irq, priv->can.clock.freq); 591 return 0; 592 593exit_candev_free: 594 free_candev(dev); 595exit_peri_pin_free: 596 peripheral_free_list(pdata); 597exit_mem_release: 598 release_mem_region(res_mem->start, resource_size(res_mem)); 599exit: 600 return err; 601} 602 603static int __devexit bfin_can_remove(struct platform_device *pdev) 604{ 605 struct net_device *dev = dev_get_drvdata(&pdev->dev); 606 struct bfin_can_priv *priv = netdev_priv(dev); 607 struct resource *res; 608 609 bfin_can_set_reset_mode(dev); 610 611 unregister_candev(dev); 612 613 dev_set_drvdata(&pdev->dev, NULL); 614 615 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 616 release_mem_region(res->start, resource_size(res)); 617 618 peripheral_free_list(priv->pin_list); 619 620 free_candev(dev); 621 return 0; 622} 623 624#ifdef CONFIG_PM 625static int bfin_can_suspend(struct platform_device *pdev, pm_message_t mesg) 626{ 627 struct net_device *dev = dev_get_drvdata(&pdev->dev); 628 struct bfin_can_priv *priv = netdev_priv(dev); 629 struct bfin_can_regs __iomem *reg = priv->membase; 630 int timeout = BFIN_CAN_TIMEOUT; 631 632 if (netif_running(dev)) { 633 /* enter sleep mode */ 634 bfin_write(®->control, bfin_read(®->control) | SMR); 635 SSYNC(); 636 while (!(bfin_read(®->intr) & SMACK)) { 637 udelay(10); 638 if (--timeout == 0) { 639 dev_err(dev->dev.parent, 640 "fail to enter sleep mode\n"); 641 BUG(); 642 } 643 } 644 } 645 646 return 0; 647} 648 649static int bfin_can_resume(struct platform_device *pdev) 650{ 651 struct net_device *dev = dev_get_drvdata(&pdev->dev); 652 struct bfin_can_priv *priv = netdev_priv(dev); 653 struct bfin_can_regs __iomem *reg = priv->membase; 654 655 if (netif_running(dev)) { 656 /* leave sleep mode */ 657 bfin_write(®->intr, 0); 658 SSYNC(); 659 } 660 661 return 0; 662} 663#else 664#define bfin_can_suspend NULL 665#define bfin_can_resume NULL 666#endif /* CONFIG_PM */ 667 668static struct platform_driver bfin_can_driver = { 669 .probe = bfin_can_probe, 670 .remove = __devexit_p(bfin_can_remove), 671 .suspend = bfin_can_suspend, 672 .resume = bfin_can_resume, 673 .driver = { 674 .name = DRV_NAME, 675 .owner = THIS_MODULE, 676 }, 677}; 678 679static int __init bfin_can_init(void) 680{ 681 return platform_driver_register(&bfin_can_driver); 682} 683module_init(bfin_can_init); 684 685static void __exit bfin_can_exit(void) 686{ 687 platform_driver_unregister(&bfin_can_driver); 688} 689module_exit(bfin_can_exit); 690 691MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); 692MODULE_LICENSE("GPL"); 693MODULE_DESCRIPTION("Blackfin on-chip CAN netdevice driver"); 694