1/* 2 * Janz MODULbus VMOD-ICAN3 CAN Interface Driver 3 * 4 * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu> 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License as published by the 8 * Free Software Foundation; either version 2 of the License, or (at your 9 * option) any later version. 10 */ 11 12#include <linux/kernel.h> 13#include <linux/module.h> 14#include <linux/interrupt.h> 15#include <linux/delay.h> 16#include <linux/platform_device.h> 17 18#include <linux/netdevice.h> 19#include <linux/can.h> 20#include <linux/can/dev.h> 21#include <linux/can/skb.h> 22#include <linux/can/error.h> 23 24#include <linux/mfd/janz.h> 25#include <asm/io.h> 26 27/* the DPM has 64k of memory, organized into 256x 256 byte pages */ 28#define DPM_NUM_PAGES 256 29#define DPM_PAGE_SIZE 256 30#define DPM_PAGE_ADDR(p) ((p) * DPM_PAGE_SIZE) 31 32/* JANZ ICAN3 "old-style" host interface queue page numbers */ 33#define QUEUE_OLD_CONTROL 0 34#define QUEUE_OLD_RB0 1 35#define QUEUE_OLD_RB1 2 36#define QUEUE_OLD_WB0 3 37#define QUEUE_OLD_WB1 4 38 39/* Janz ICAN3 "old-style" host interface control registers */ 40#define MSYNC_PEER 0x00 /* ICAN only */ 41#define MSYNC_LOCL 0x01 /* host only */ 42#define TARGET_RUNNING 0x02 43 44#define MSYNC_RB0 0x01 45#define MSYNC_RB1 0x02 46#define MSYNC_RBLW 0x04 47#define MSYNC_RB_MASK (MSYNC_RB0 | MSYNC_RB1) 48 49#define MSYNC_WB0 0x10 50#define MSYNC_WB1 0x20 51#define MSYNC_WBLW 0x40 52#define MSYNC_WB_MASK (MSYNC_WB0 | MSYNC_WB1) 53 54/* Janz ICAN3 "new-style" host interface queue page numbers */ 55#define QUEUE_TOHOST 5 56#define QUEUE_FROMHOST_MID 6 57#define QUEUE_FROMHOST_HIGH 7 58#define QUEUE_FROMHOST_LOW 8 59 60/* The first free page in the DPM is #9 */ 61#define DPM_FREE_START 9 62 63/* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */ 64#define DESC_VALID 0x80 65#define DESC_WRAP 0x40 66#define DESC_INTERRUPT 0x20 67#define DESC_IVALID 0x10 68#define DESC_LEN(len) (len) 69 70/* Janz ICAN3 Firmware Messages */ 71#define MSG_CONNECTI 0x02 72#define MSG_DISCONNECT 0x03 73#define MSG_IDVERS 0x04 74#define MSG_MSGLOST 0x05 75#define MSG_NEWHOSTIF 0x08 76#define MSG_INQUIRY 0x0a 77#define MSG_SETAFILMASK 0x10 78#define MSG_INITFDPMQUEUE 0x11 79#define MSG_HWCONF 0x12 80#define MSG_FMSGLOST 0x15 81#define MSG_CEVTIND 0x37 82#define MSG_CBTRREQ 0x41 83#define MSG_COFFREQ 0x42 84#define MSG_CONREQ 0x43 85#define MSG_CCONFREQ 0x47 86 87/* 88 * Janz ICAN3 CAN Inquiry Message Types 89 * 90 * NOTE: there appears to be a firmware bug here. You must send 91 * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED 92 * NOTE: response. The controller never responds to a message with 93 * NOTE: the INQUIRY_EXTENDED subspec :( 94 */ 95#define INQUIRY_STATUS 0x00 96#define INQUIRY_TERMINATION 0x01 97#define INQUIRY_EXTENDED 0x04 98 99/* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */ 100#define SETAFILMASK_REJECT 0x00 101#define SETAFILMASK_FASTIF 0x02 102 103/* Janz ICAN3 CAN Hardware Configuration Message Types */ 104#define HWCONF_TERMINATE_ON 0x01 105#define HWCONF_TERMINATE_OFF 0x00 106 107/* Janz ICAN3 CAN Event Indication Message Types */ 108#define CEVTIND_EI 0x01 109#define CEVTIND_DOI 0x02 110#define CEVTIND_LOST 0x04 111#define CEVTIND_FULL 0x08 112#define CEVTIND_BEI 0x10 113 114#define CEVTIND_CHIP_SJA1000 0x02 115 116#define ICAN3_BUSERR_QUOTA_MAX 255 117 118/* Janz ICAN3 CAN Frame Conversion */ 119#define ICAN3_SNGL 0x02 120#define ICAN3_ECHO 0x10 121#define ICAN3_EFF_RTR 0x40 122#define ICAN3_SFF_RTR 0x10 123#define ICAN3_EFF 0x80 124 125#define ICAN3_CAN_TYPE_MASK 0x0f 126#define ICAN3_CAN_TYPE_SFF 0x00 127#define ICAN3_CAN_TYPE_EFF 0x01 128 129#define ICAN3_CAN_DLC_MASK 0x0f 130 131/* 132 * SJA1000 Status and Error Register Definitions 133 * 134 * Copied from drivers/net/can/sja1000/sja1000.h 135 */ 136 137/* status register content */ 138#define SR_BS 0x80 139#define SR_ES 0x40 140#define SR_TS 0x20 141#define SR_RS 0x10 142#define SR_TCS 0x08 143#define SR_TBS 0x04 144#define SR_DOS 0x02 145#define SR_RBS 0x01 146 147#define SR_CRIT (SR_BS|SR_ES) 148 149/* ECC register */ 150#define ECC_SEG 0x1F 151#define ECC_DIR 0x20 152#define ECC_ERR 6 153#define ECC_BIT 0x00 154#define ECC_FORM 0x40 155#define ECC_STUFF 0x80 156#define ECC_MASK 0xc0 157 158/* Number of buffers for use in the "new-style" host interface */ 159#define ICAN3_NEW_BUFFERS 16 160 161/* Number of buffers for use in the "fast" host interface */ 162#define ICAN3_TX_BUFFERS 512 163#define ICAN3_RX_BUFFERS 1024 164 165/* SJA1000 Clock Input */ 166#define ICAN3_CAN_CLOCK 8000000 167 168/* Driver Name */ 169#define DRV_NAME "janz-ican3" 170 171/* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */ 172struct ican3_dpm_control { 173 /* window address register */ 174 u8 window_address; 175 u8 unused1; 176 177 /* 178 * Read access: clear interrupt from microcontroller 179 * Write access: send interrupt to microcontroller 180 */ 181 u8 interrupt; 182 u8 unused2; 183 184 /* write-only: reset all hardware on the module */ 185 u8 hwreset; 186 u8 unused3; 187 188 /* write-only: generate an interrupt to the TPU */ 189 u8 tpuinterrupt; 190}; 191 192struct ican3_dev { 193 194 /* must be the first member */ 195 struct can_priv can; 196 197 /* CAN network device */ 198 struct net_device *ndev; 199 struct napi_struct napi; 200 201 /* module number */ 202 unsigned int num; 203 204 /* base address of registers and IRQ */ 205 struct janz_cmodio_onboard_regs __iomem *ctrl; 206 struct ican3_dpm_control __iomem *dpmctrl; 207 void __iomem *dpm; 208 int irq; 209 210 /* CAN bus termination status */ 211 struct completion termination_comp; 212 bool termination_enabled; 213 214 /* CAN bus error status registers */ 215 struct completion buserror_comp; 216 struct can_berr_counter bec; 217 218 /* old and new style host interface */ 219 unsigned int iftype; 220 221 /* queue for echo packets */ 222 struct sk_buff_head echoq; 223 224 /* 225 * Any function which changes the current DPM page must hold this 226 * lock while it is performing data accesses. This ensures that the 227 * function will not be preempted and end up reading data from a 228 * different DPM page than it expects. 229 */ 230 spinlock_t lock; 231 232 /* new host interface */ 233 unsigned int rx_int; 234 unsigned int rx_num; 235 unsigned int tx_num; 236 237 /* fast host interface */ 238 unsigned int fastrx_start; 239 unsigned int fastrx_num; 240 unsigned int fasttx_start; 241 unsigned int fasttx_num; 242 243 /* first free DPM page */ 244 unsigned int free_page; 245}; 246 247struct ican3_msg { 248 u8 control; 249 u8 spec; 250 __le16 len; 251 u8 data[252]; 252}; 253 254struct ican3_new_desc { 255 u8 control; 256 u8 pointer; 257}; 258 259struct ican3_fast_desc { 260 u8 control; 261 u8 command; 262 u8 data[14]; 263}; 264 265/* write to the window basic address register */ 266static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page) 267{ 268 BUG_ON(page >= DPM_NUM_PAGES); 269 iowrite8(page, &mod->dpmctrl->window_address); 270} 271 272/* 273 * ICAN3 "old-style" host interface 274 */ 275 276/* 277 * Receive a message from the ICAN3 "old-style" firmware interface 278 * 279 * LOCKING: must hold mod->lock 280 * 281 * returns 0 on success, -ENOMEM when no message exists 282 */ 283static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 284{ 285 unsigned int mbox, mbox_page; 286 u8 locl, peer, xord; 287 288 /* get the MSYNC registers */ 289 ican3_set_page(mod, QUEUE_OLD_CONTROL); 290 peer = ioread8(mod->dpm + MSYNC_PEER); 291 locl = ioread8(mod->dpm + MSYNC_LOCL); 292 xord = locl ^ peer; 293 294 if ((xord & MSYNC_RB_MASK) == 0x00) { 295 netdev_dbg(mod->ndev, "no mbox for reading\n"); 296 return -ENOMEM; 297 } 298 299 /* find the first free mbox to read */ 300 if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK) 301 mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1; 302 else 303 mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1; 304 305 /* copy the message */ 306 mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1; 307 ican3_set_page(mod, mbox_page); 308 memcpy_fromio(msg, mod->dpm, sizeof(*msg)); 309 310 /* 311 * notify the firmware that the read buffer is available 312 * for it to fill again 313 */ 314 locl ^= mbox; 315 316 ican3_set_page(mod, QUEUE_OLD_CONTROL); 317 iowrite8(locl, mod->dpm + MSYNC_LOCL); 318 return 0; 319} 320 321/* 322 * Send a message through the "old-style" firmware interface 323 * 324 * LOCKING: must hold mod->lock 325 * 326 * returns 0 on success, -ENOMEM when no free space exists 327 */ 328static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 329{ 330 unsigned int mbox, mbox_page; 331 u8 locl, peer, xord; 332 333 /* get the MSYNC registers */ 334 ican3_set_page(mod, QUEUE_OLD_CONTROL); 335 peer = ioread8(mod->dpm + MSYNC_PEER); 336 locl = ioread8(mod->dpm + MSYNC_LOCL); 337 xord = locl ^ peer; 338 339 if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) { 340 netdev_err(mod->ndev, "no mbox for writing\n"); 341 return -ENOMEM; 342 } 343 344 /* calculate a free mbox to use */ 345 mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0; 346 347 /* copy the message to the DPM */ 348 mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1; 349 ican3_set_page(mod, mbox_page); 350 memcpy_toio(mod->dpm, msg, sizeof(*msg)); 351 352 locl ^= mbox; 353 if (mbox == MSYNC_WB1) 354 locl |= MSYNC_WBLW; 355 356 ican3_set_page(mod, QUEUE_OLD_CONTROL); 357 iowrite8(locl, mod->dpm + MSYNC_LOCL); 358 return 0; 359} 360 361/* 362 * ICAN3 "new-style" Host Interface Setup 363 */ 364 365static void ican3_init_new_host_interface(struct ican3_dev *mod) 366{ 367 struct ican3_new_desc desc; 368 unsigned long flags; 369 void __iomem *dst; 370 int i; 371 372 spin_lock_irqsave(&mod->lock, flags); 373 374 /* setup the internal datastructures for RX */ 375 mod->rx_num = 0; 376 mod->rx_int = 0; 377 378 /* tohost queue descriptors are in page 5 */ 379 ican3_set_page(mod, QUEUE_TOHOST); 380 dst = mod->dpm; 381 382 /* initialize the tohost (rx) queue descriptors: pages 9-24 */ 383 for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { 384 desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */ 385 desc.pointer = mod->free_page; 386 387 /* set wrap flag on last buffer */ 388 if (i == ICAN3_NEW_BUFFERS - 1) 389 desc.control |= DESC_WRAP; 390 391 memcpy_toio(dst, &desc, sizeof(desc)); 392 dst += sizeof(desc); 393 mod->free_page++; 394 } 395 396 /* fromhost (tx) mid queue descriptors are in page 6 */ 397 ican3_set_page(mod, QUEUE_FROMHOST_MID); 398 dst = mod->dpm; 399 400 /* setup the internal datastructures for TX */ 401 mod->tx_num = 0; 402 403 /* initialize the fromhost mid queue descriptors: pages 25-40 */ 404 for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { 405 desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */ 406 desc.pointer = mod->free_page; 407 408 /* set wrap flag on last buffer */ 409 if (i == ICAN3_NEW_BUFFERS - 1) 410 desc.control |= DESC_WRAP; 411 412 memcpy_toio(dst, &desc, sizeof(desc)); 413 dst += sizeof(desc); 414 mod->free_page++; 415 } 416 417 /* fromhost hi queue descriptors are in page 7 */ 418 ican3_set_page(mod, QUEUE_FROMHOST_HIGH); 419 dst = mod->dpm; 420 421 /* initialize only a single buffer in the fromhost hi queue (unused) */ 422 desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ 423 desc.pointer = mod->free_page; 424 memcpy_toio(dst, &desc, sizeof(desc)); 425 mod->free_page++; 426 427 /* fromhost low queue descriptors are in page 8 */ 428 ican3_set_page(mod, QUEUE_FROMHOST_LOW); 429 dst = mod->dpm; 430 431 /* initialize only a single buffer in the fromhost low queue (unused) */ 432 desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ 433 desc.pointer = mod->free_page; 434 memcpy_toio(dst, &desc, sizeof(desc)); 435 mod->free_page++; 436 437 spin_unlock_irqrestore(&mod->lock, flags); 438} 439 440/* 441 * ICAN3 Fast Host Interface Setup 442 */ 443 444static void ican3_init_fast_host_interface(struct ican3_dev *mod) 445{ 446 struct ican3_fast_desc desc; 447 unsigned long flags; 448 unsigned int addr; 449 void __iomem *dst; 450 int i; 451 452 spin_lock_irqsave(&mod->lock, flags); 453 454 /* save the start recv page */ 455 mod->fastrx_start = mod->free_page; 456 mod->fastrx_num = 0; 457 458 /* build a single fast tohost queue descriptor */ 459 memset(&desc, 0, sizeof(desc)); 460 desc.control = 0x00; 461 desc.command = 1; 462 463 /* build the tohost queue descriptor ring in memory */ 464 addr = 0; 465 for (i = 0; i < ICAN3_RX_BUFFERS; i++) { 466 467 /* set the wrap bit on the last buffer */ 468 if (i == ICAN3_RX_BUFFERS - 1) 469 desc.control |= DESC_WRAP; 470 471 /* switch to the correct page */ 472 ican3_set_page(mod, mod->free_page); 473 474 /* copy the descriptor to the DPM */ 475 dst = mod->dpm + addr; 476 memcpy_toio(dst, &desc, sizeof(desc)); 477 addr += sizeof(desc); 478 479 /* move to the next page if necessary */ 480 if (addr >= DPM_PAGE_SIZE) { 481 addr = 0; 482 mod->free_page++; 483 } 484 } 485 486 /* make sure we page-align the next queue */ 487 if (addr != 0) 488 mod->free_page++; 489 490 /* save the start xmit page */ 491 mod->fasttx_start = mod->free_page; 492 mod->fasttx_num = 0; 493 494 /* build a single fast fromhost queue descriptor */ 495 memset(&desc, 0, sizeof(desc)); 496 desc.control = DESC_VALID; 497 desc.command = 1; 498 499 /* build the fromhost queue descriptor ring in memory */ 500 addr = 0; 501 for (i = 0; i < ICAN3_TX_BUFFERS; i++) { 502 503 /* set the wrap bit on the last buffer */ 504 if (i == ICAN3_TX_BUFFERS - 1) 505 desc.control |= DESC_WRAP; 506 507 /* switch to the correct page */ 508 ican3_set_page(mod, mod->free_page); 509 510 /* copy the descriptor to the DPM */ 511 dst = mod->dpm + addr; 512 memcpy_toio(dst, &desc, sizeof(desc)); 513 addr += sizeof(desc); 514 515 /* move to the next page if necessary */ 516 if (addr >= DPM_PAGE_SIZE) { 517 addr = 0; 518 mod->free_page++; 519 } 520 } 521 522 spin_unlock_irqrestore(&mod->lock, flags); 523} 524 525/* 526 * ICAN3 "new-style" Host Interface Message Helpers 527 */ 528 529/* 530 * LOCKING: must hold mod->lock 531 */ 532static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 533{ 534 struct ican3_new_desc desc; 535 void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc)); 536 537 /* switch to the fromhost mid queue, and read the buffer descriptor */ 538 ican3_set_page(mod, QUEUE_FROMHOST_MID); 539 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 540 541 if (!(desc.control & DESC_VALID)) { 542 netdev_dbg(mod->ndev, "%s: no free buffers\n", __func__); 543 return -ENOMEM; 544 } 545 546 /* switch to the data page, copy the data */ 547 ican3_set_page(mod, desc.pointer); 548 memcpy_toio(mod->dpm, msg, sizeof(*msg)); 549 550 /* switch back to the descriptor, set the valid bit, write it back */ 551 ican3_set_page(mod, QUEUE_FROMHOST_MID); 552 desc.control ^= DESC_VALID; 553 memcpy_toio(desc_addr, &desc, sizeof(desc)); 554 555 /* update the tx number */ 556 mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1); 557 return 0; 558} 559 560/* 561 * LOCKING: must hold mod->lock 562 */ 563static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 564{ 565 struct ican3_new_desc desc; 566 void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc)); 567 568 /* switch to the tohost queue, and read the buffer descriptor */ 569 ican3_set_page(mod, QUEUE_TOHOST); 570 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 571 572 if (!(desc.control & DESC_VALID)) { 573 netdev_dbg(mod->ndev, "%s: no buffers to recv\n", __func__); 574 return -ENOMEM; 575 } 576 577 /* switch to the data page, copy the data */ 578 ican3_set_page(mod, desc.pointer); 579 memcpy_fromio(msg, mod->dpm, sizeof(*msg)); 580 581 /* switch back to the descriptor, toggle the valid bit, write it back */ 582 ican3_set_page(mod, QUEUE_TOHOST); 583 desc.control ^= DESC_VALID; 584 memcpy_toio(desc_addr, &desc, sizeof(desc)); 585 586 /* update the rx number */ 587 mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1); 588 return 0; 589} 590 591/* 592 * Message Send / Recv Helpers 593 */ 594 595static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 596{ 597 unsigned long flags; 598 int ret; 599 600 spin_lock_irqsave(&mod->lock, flags); 601 602 if (mod->iftype == 0) 603 ret = ican3_old_send_msg(mod, msg); 604 else 605 ret = ican3_new_send_msg(mod, msg); 606 607 spin_unlock_irqrestore(&mod->lock, flags); 608 return ret; 609} 610 611static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 612{ 613 unsigned long flags; 614 int ret; 615 616 spin_lock_irqsave(&mod->lock, flags); 617 618 if (mod->iftype == 0) 619 ret = ican3_old_recv_msg(mod, msg); 620 else 621 ret = ican3_new_recv_msg(mod, msg); 622 623 spin_unlock_irqrestore(&mod->lock, flags); 624 return ret; 625} 626 627/* 628 * Quick Pre-constructed Messages 629 */ 630 631static int ican3_msg_connect(struct ican3_dev *mod) 632{ 633 struct ican3_msg msg; 634 635 memset(&msg, 0, sizeof(msg)); 636 msg.spec = MSG_CONNECTI; 637 msg.len = cpu_to_le16(0); 638 639 return ican3_send_msg(mod, &msg); 640} 641 642static int ican3_msg_disconnect(struct ican3_dev *mod) 643{ 644 struct ican3_msg msg; 645 646 memset(&msg, 0, sizeof(msg)); 647 msg.spec = MSG_DISCONNECT; 648 msg.len = cpu_to_le16(0); 649 650 return ican3_send_msg(mod, &msg); 651} 652 653static int ican3_msg_newhostif(struct ican3_dev *mod) 654{ 655 struct ican3_msg msg; 656 int ret; 657 658 memset(&msg, 0, sizeof(msg)); 659 msg.spec = MSG_NEWHOSTIF; 660 msg.len = cpu_to_le16(0); 661 662 /* If we're not using the old interface, switching seems bogus */ 663 WARN_ON(mod->iftype != 0); 664 665 ret = ican3_send_msg(mod, &msg); 666 if (ret) 667 return ret; 668 669 /* mark the module as using the new host interface */ 670 mod->iftype = 1; 671 return 0; 672} 673 674static int ican3_msg_fasthostif(struct ican3_dev *mod) 675{ 676 struct ican3_msg msg; 677 unsigned int addr; 678 679 memset(&msg, 0, sizeof(msg)); 680 msg.spec = MSG_INITFDPMQUEUE; 681 msg.len = cpu_to_le16(8); 682 683 /* write the tohost queue start address */ 684 addr = DPM_PAGE_ADDR(mod->fastrx_start); 685 msg.data[0] = addr & 0xff; 686 msg.data[1] = (addr >> 8) & 0xff; 687 msg.data[2] = (addr >> 16) & 0xff; 688 msg.data[3] = (addr >> 24) & 0xff; 689 690 /* write the fromhost queue start address */ 691 addr = DPM_PAGE_ADDR(mod->fasttx_start); 692 msg.data[4] = addr & 0xff; 693 msg.data[5] = (addr >> 8) & 0xff; 694 msg.data[6] = (addr >> 16) & 0xff; 695 msg.data[7] = (addr >> 24) & 0xff; 696 697 /* If we're not using the new interface yet, we cannot do this */ 698 WARN_ON(mod->iftype != 1); 699 700 return ican3_send_msg(mod, &msg); 701} 702 703/* 704 * Setup the CAN filter to either accept or reject all 705 * messages from the CAN bus. 706 */ 707static int ican3_set_id_filter(struct ican3_dev *mod, bool accept) 708{ 709 struct ican3_msg msg; 710 int ret; 711 712 /* Standard Frame Format */ 713 memset(&msg, 0, sizeof(msg)); 714 msg.spec = MSG_SETAFILMASK; 715 msg.len = cpu_to_le16(5); 716 msg.data[0] = 0x00; /* IDLo LSB */ 717 msg.data[1] = 0x00; /* IDLo MSB */ 718 msg.data[2] = 0xff; /* IDHi LSB */ 719 msg.data[3] = 0x07; /* IDHi MSB */ 720 721 /* accept all frames for fast host if, or reject all frames */ 722 msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; 723 724 ret = ican3_send_msg(mod, &msg); 725 if (ret) 726 return ret; 727 728 /* Extended Frame Format */ 729 memset(&msg, 0, sizeof(msg)); 730 msg.spec = MSG_SETAFILMASK; 731 msg.len = cpu_to_le16(13); 732 msg.data[0] = 0; /* MUX = 0 */ 733 msg.data[1] = 0x00; /* IDLo LSB */ 734 msg.data[2] = 0x00; 735 msg.data[3] = 0x00; 736 msg.data[4] = 0x20; /* IDLo MSB */ 737 msg.data[5] = 0xff; /* IDHi LSB */ 738 msg.data[6] = 0xff; 739 msg.data[7] = 0xff; 740 msg.data[8] = 0x3f; /* IDHi MSB */ 741 742 /* accept all frames for fast host if, or reject all frames */ 743 msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; 744 745 return ican3_send_msg(mod, &msg); 746} 747 748/* 749 * Bring the CAN bus online or offline 750 */ 751static int ican3_set_bus_state(struct ican3_dev *mod, bool on) 752{ 753 struct ican3_msg msg; 754 755 memset(&msg, 0, sizeof(msg)); 756 msg.spec = on ? MSG_CONREQ : MSG_COFFREQ; 757 msg.len = cpu_to_le16(0); 758 759 return ican3_send_msg(mod, &msg); 760} 761 762static int ican3_set_termination(struct ican3_dev *mod, bool on) 763{ 764 struct ican3_msg msg; 765 766 memset(&msg, 0, sizeof(msg)); 767 msg.spec = MSG_HWCONF; 768 msg.len = cpu_to_le16(2); 769 msg.data[0] = 0x00; 770 msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF; 771 772 return ican3_send_msg(mod, &msg); 773} 774 775static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec) 776{ 777 struct ican3_msg msg; 778 779 memset(&msg, 0, sizeof(msg)); 780 msg.spec = MSG_INQUIRY; 781 msg.len = cpu_to_le16(2); 782 msg.data[0] = subspec; 783 msg.data[1] = 0x00; 784 785 return ican3_send_msg(mod, &msg); 786} 787 788static int ican3_set_buserror(struct ican3_dev *mod, u8 quota) 789{ 790 struct ican3_msg msg; 791 792 memset(&msg, 0, sizeof(msg)); 793 msg.spec = MSG_CCONFREQ; 794 msg.len = cpu_to_le16(2); 795 msg.data[0] = 0x00; 796 msg.data[1] = quota; 797 798 return ican3_send_msg(mod, &msg); 799} 800 801/* 802 * ICAN3 to Linux CAN Frame Conversion 803 */ 804 805static void ican3_to_can_frame(struct ican3_dev *mod, 806 struct ican3_fast_desc *desc, 807 struct can_frame *cf) 808{ 809 if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) { 810 if (desc->data[1] & ICAN3_SFF_RTR) 811 cf->can_id |= CAN_RTR_FLAG; 812 813 cf->can_id |= desc->data[0] << 3; 814 cf->can_id |= (desc->data[1] & 0xe0) >> 5; 815 cf->can_dlc = get_can_dlc(desc->data[1] & ICAN3_CAN_DLC_MASK); 816 memcpy(cf->data, &desc->data[2], cf->can_dlc); 817 } else { 818 cf->can_dlc = get_can_dlc(desc->data[0] & ICAN3_CAN_DLC_MASK); 819 if (desc->data[0] & ICAN3_EFF_RTR) 820 cf->can_id |= CAN_RTR_FLAG; 821 822 if (desc->data[0] & ICAN3_EFF) { 823 cf->can_id |= CAN_EFF_FLAG; 824 cf->can_id |= desc->data[2] << 21; /* 28-21 */ 825 cf->can_id |= desc->data[3] << 13; /* 20-13 */ 826 cf->can_id |= desc->data[4] << 5; /* 12-5 */ 827 cf->can_id |= (desc->data[5] & 0xf8) >> 3; 828 } else { 829 cf->can_id |= desc->data[2] << 3; /* 10-3 */ 830 cf->can_id |= desc->data[3] >> 5; /* 2-0 */ 831 } 832 833 memcpy(cf->data, &desc->data[6], cf->can_dlc); 834 } 835} 836 837static void can_frame_to_ican3(struct ican3_dev *mod, 838 struct can_frame *cf, 839 struct ican3_fast_desc *desc) 840{ 841 /* clear out any stale data in the descriptor */ 842 memset(desc->data, 0, sizeof(desc->data)); 843 844 /* we always use the extended format, with the ECHO flag set */ 845 desc->command = ICAN3_CAN_TYPE_EFF; 846 desc->data[0] |= cf->can_dlc; 847 desc->data[1] |= ICAN3_ECHO; 848 849 /* support single transmission (no retries) mode */ 850 if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) 851 desc->data[1] |= ICAN3_SNGL; 852 853 if (cf->can_id & CAN_RTR_FLAG) 854 desc->data[0] |= ICAN3_EFF_RTR; 855 856 /* pack the id into the correct places */ 857 if (cf->can_id & CAN_EFF_FLAG) { 858 desc->data[0] |= ICAN3_EFF; 859 desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */ 860 desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */ 861 desc->data[4] = (cf->can_id & 0x00001fe0) >> 5; /* 12-5 */ 862 desc->data[5] = (cf->can_id & 0x0000001f) << 3; /* 4-0 */ 863 } else { 864 desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */ 865 desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0 */ 866 } 867 868 /* copy the data bits into the descriptor */ 869 memcpy(&desc->data[6], cf->data, cf->can_dlc); 870} 871 872/* 873 * Interrupt Handling 874 */ 875 876/* 877 * Handle an ID + Version message response from the firmware. We never generate 878 * this message in production code, but it is very useful when debugging to be 879 * able to display this message. 880 */ 881static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg) 882{ 883 netdev_dbg(mod->ndev, "IDVERS response: %s\n", msg->data); 884} 885 886static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg) 887{ 888 struct net_device *dev = mod->ndev; 889 struct net_device_stats *stats = &dev->stats; 890 struct can_frame *cf; 891 struct sk_buff *skb; 892 893 /* 894 * Report that communication messages with the microcontroller firmware 895 * are being lost. These are never CAN frames, so we do not generate an 896 * error frame for userspace 897 */ 898 if (msg->spec == MSG_MSGLOST) { 899 netdev_err(mod->ndev, "lost %d control messages\n", msg->data[0]); 900 return; 901 } 902 903 /* 904 * Oops, this indicates that we have lost messages in the fast queue, 905 * which are exclusively CAN messages. Our driver isn't reading CAN 906 * frames fast enough. 907 * 908 * We'll pretend that the SJA1000 told us that it ran out of buffer 909 * space, because there is not a better message for this. 910 */ 911 skb = alloc_can_err_skb(dev, &cf); 912 if (skb) { 913 cf->can_id |= CAN_ERR_CRTL; 914 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 915 stats->rx_over_errors++; 916 stats->rx_errors++; 917 netif_rx(skb); 918 } 919} 920 921/* 922 * Handle CAN Event Indication Messages from the firmware 923 * 924 * The ICAN3 firmware provides the values of some SJA1000 registers when it 925 * generates this message. The code below is largely copied from the 926 * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary 927 */ 928static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg) 929{ 930 struct net_device *dev = mod->ndev; 931 struct net_device_stats *stats = &dev->stats; 932 enum can_state state = mod->can.state; 933 u8 isrc, ecc, status, rxerr, txerr; 934 struct can_frame *cf; 935 struct sk_buff *skb; 936 937 /* we can only handle the SJA1000 part */ 938 if (msg->data[1] != CEVTIND_CHIP_SJA1000) { 939 netdev_err(mod->ndev, "unable to handle errors on non-SJA1000\n"); 940 return -ENODEV; 941 } 942 943 /* check the message length for sanity */ 944 if (le16_to_cpu(msg->len) < 6) { 945 netdev_err(mod->ndev, "error message too short\n"); 946 return -EINVAL; 947 } 948 949 isrc = msg->data[0]; 950 ecc = msg->data[2]; 951 status = msg->data[3]; 952 rxerr = msg->data[4]; 953 txerr = msg->data[5]; 954 955 /* 956 * This hardware lacks any support other than bus error messages to 957 * determine if packet transmission has failed. 958 * 959 * When TX errors happen, one echo skb needs to be dropped from the 960 * front of the queue. 961 * 962 * A small bit of code is duplicated here and below, to avoid error 963 * skb allocation when it will just be freed immediately. 964 */ 965 if (isrc == CEVTIND_BEI) { 966 int ret; 967 netdev_dbg(mod->ndev, "bus error interrupt\n"); 968 969 /* TX error */ 970 if (!(ecc & ECC_DIR)) { 971 kfree_skb(skb_dequeue(&mod->echoq)); 972 stats->tx_errors++; 973 } else { 974 stats->rx_errors++; 975 } 976 977 /* 978 * The controller automatically disables bus-error interrupts 979 * and therefore we must re-enable them. 980 */ 981 ret = ican3_set_buserror(mod, 1); 982 if (ret) { 983 netdev_err(mod->ndev, "unable to re-enable bus-error\n"); 984 return ret; 985 } 986 987 /* bus error reporting is off, return immediately */ 988 if (!(mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) 989 return 0; 990 } 991 992 skb = alloc_can_err_skb(dev, &cf); 993 if (skb == NULL) 994 return -ENOMEM; 995 996 /* data overrun interrupt */ 997 if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) { 998 netdev_dbg(mod->ndev, "data overrun interrupt\n"); 999 cf->can_id |= CAN_ERR_CRTL; 1000 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 1001 stats->rx_over_errors++; 1002 stats->rx_errors++; 1003 } 1004 1005 /* error warning + passive interrupt */ 1006 if (isrc == CEVTIND_EI) { 1007 netdev_dbg(mod->ndev, "error warning + passive interrupt\n"); 1008 if (status & SR_BS) { 1009 state = CAN_STATE_BUS_OFF; 1010 cf->can_id |= CAN_ERR_BUSOFF; 1011 mod->can.can_stats.bus_off++; 1012 can_bus_off(dev); 1013 } else if (status & SR_ES) { 1014 if (rxerr >= 128 || txerr >= 128) 1015 state = CAN_STATE_ERROR_PASSIVE; 1016 else 1017 state = CAN_STATE_ERROR_WARNING; 1018 } else { 1019 state = CAN_STATE_ERROR_ACTIVE; 1020 } 1021 } 1022 1023 /* bus error interrupt */ 1024 if (isrc == CEVTIND_BEI) { 1025 mod->can.can_stats.bus_error++; 1026 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 1027 1028 switch (ecc & ECC_MASK) { 1029 case ECC_BIT: 1030 cf->data[2] |= CAN_ERR_PROT_BIT; 1031 break; 1032 case ECC_FORM: 1033 cf->data[2] |= CAN_ERR_PROT_FORM; 1034 break; 1035 case ECC_STUFF: 1036 cf->data[2] |= CAN_ERR_PROT_STUFF; 1037 break; 1038 default: 1039 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 1040 cf->data[3] = ecc & ECC_SEG; 1041 break; 1042 } 1043 1044 if (!(ecc & ECC_DIR)) 1045 cf->data[2] |= CAN_ERR_PROT_TX; 1046 1047 cf->data[6] = txerr; 1048 cf->data[7] = rxerr; 1049 } 1050 1051 if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING || 1052 state == CAN_STATE_ERROR_PASSIVE)) { 1053 cf->can_id |= CAN_ERR_CRTL; 1054 if (state == CAN_STATE_ERROR_WARNING) { 1055 mod->can.can_stats.error_warning++; 1056 cf->data[1] = (txerr > rxerr) ? 1057 CAN_ERR_CRTL_TX_WARNING : 1058 CAN_ERR_CRTL_RX_WARNING; 1059 } else { 1060 mod->can.can_stats.error_passive++; 1061 cf->data[1] = (txerr > rxerr) ? 1062 CAN_ERR_CRTL_TX_PASSIVE : 1063 CAN_ERR_CRTL_RX_PASSIVE; 1064 } 1065 1066 cf->data[6] = txerr; 1067 cf->data[7] = rxerr; 1068 } 1069 1070 mod->can.state = state; 1071 netif_rx(skb); 1072 return 0; 1073} 1074 1075static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg) 1076{ 1077 switch (msg->data[0]) { 1078 case INQUIRY_STATUS: 1079 case INQUIRY_EXTENDED: 1080 mod->bec.rxerr = msg->data[5]; 1081 mod->bec.txerr = msg->data[6]; 1082 complete(&mod->buserror_comp); 1083 break; 1084 case INQUIRY_TERMINATION: 1085 mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON; 1086 complete(&mod->termination_comp); 1087 break; 1088 default: 1089 netdev_err(mod->ndev, "received an unknown inquiry response\n"); 1090 break; 1091 } 1092} 1093 1094static void ican3_handle_unknown_message(struct ican3_dev *mod, 1095 struct ican3_msg *msg) 1096{ 1097 netdev_warn(mod->ndev, "received unknown message: spec 0x%.2x length %d\n", 1098 msg->spec, le16_to_cpu(msg->len)); 1099} 1100 1101/* 1102 * Handle a control message from the firmware 1103 */ 1104static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg) 1105{ 1106 netdev_dbg(mod->ndev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__, 1107 mod->num, msg->spec, le16_to_cpu(msg->len)); 1108 1109 switch (msg->spec) { 1110 case MSG_IDVERS: 1111 ican3_handle_idvers(mod, msg); 1112 break; 1113 case MSG_MSGLOST: 1114 case MSG_FMSGLOST: 1115 ican3_handle_msglost(mod, msg); 1116 break; 1117 case MSG_CEVTIND: 1118 ican3_handle_cevtind(mod, msg); 1119 break; 1120 case MSG_INQUIRY: 1121 ican3_handle_inquiry(mod, msg); 1122 break; 1123 default: 1124 ican3_handle_unknown_message(mod, msg); 1125 break; 1126 } 1127} 1128 1129/* 1130 * The ican3 needs to store all echo skbs, and therefore cannot 1131 * use the generic infrastructure for this. 1132 */ 1133static void ican3_put_echo_skb(struct ican3_dev *mod, struct sk_buff *skb) 1134{ 1135 skb = can_create_echo_skb(skb); 1136 if (!skb) 1137 return; 1138 1139 /* save this skb for tx interrupt echo handling */ 1140 skb_queue_tail(&mod->echoq, skb); 1141} 1142 1143static unsigned int ican3_get_echo_skb(struct ican3_dev *mod) 1144{ 1145 struct sk_buff *skb = skb_dequeue(&mod->echoq); 1146 struct can_frame *cf; 1147 u8 dlc; 1148 1149 /* this should never trigger unless there is a driver bug */ 1150 if (!skb) { 1151 netdev_err(mod->ndev, "BUG: echo skb not occupied\n"); 1152 return 0; 1153 } 1154 1155 cf = (struct can_frame *)skb->data; 1156 dlc = cf->can_dlc; 1157 1158 /* check flag whether this packet has to be looped back */ 1159 if (skb->pkt_type != PACKET_LOOPBACK) { 1160 kfree_skb(skb); 1161 return dlc; 1162 } 1163 1164 skb->protocol = htons(ETH_P_CAN); 1165 skb->pkt_type = PACKET_BROADCAST; 1166 skb->ip_summed = CHECKSUM_UNNECESSARY; 1167 skb->dev = mod->ndev; 1168 netif_receive_skb(skb); 1169 return dlc; 1170} 1171 1172/* 1173 * Compare an skb with an existing echo skb 1174 * 1175 * This function will be used on devices which have a hardware loopback. 1176 * On these devices, this function can be used to compare a received skb 1177 * with the saved echo skbs so that the hardware echo skb can be dropped. 1178 * 1179 * Returns true if the skb's are identical, false otherwise. 1180 */ 1181static bool ican3_echo_skb_matches(struct ican3_dev *mod, struct sk_buff *skb) 1182{ 1183 struct can_frame *cf = (struct can_frame *)skb->data; 1184 struct sk_buff *echo_skb = skb_peek(&mod->echoq); 1185 struct can_frame *echo_cf; 1186 1187 if (!echo_skb) 1188 return false; 1189 1190 echo_cf = (struct can_frame *)echo_skb->data; 1191 if (cf->can_id != echo_cf->can_id) 1192 return false; 1193 1194 if (cf->can_dlc != echo_cf->can_dlc) 1195 return false; 1196 1197 return memcmp(cf->data, echo_cf->data, cf->can_dlc) == 0; 1198} 1199 1200/* 1201 * Check that there is room in the TX ring to transmit another skb 1202 * 1203 * LOCKING: must hold mod->lock 1204 */ 1205static bool ican3_txok(struct ican3_dev *mod) 1206{ 1207 struct ican3_fast_desc __iomem *desc; 1208 u8 control; 1209 1210 /* check that we have echo queue space */ 1211 if (skb_queue_len(&mod->echoq) >= ICAN3_TX_BUFFERS) 1212 return false; 1213 1214 /* copy the control bits of the descriptor */ 1215 ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); 1216 desc = mod->dpm + ((mod->fasttx_num % 16) * sizeof(*desc)); 1217 control = ioread8(&desc->control); 1218 1219 /* if the control bits are not valid, then we have no more space */ 1220 if (!(control & DESC_VALID)) 1221 return false; 1222 1223 return true; 1224} 1225 1226/* 1227 * Receive one CAN frame from the hardware 1228 * 1229 * CONTEXT: must be called from user context 1230 */ 1231static int ican3_recv_skb(struct ican3_dev *mod) 1232{ 1233 struct net_device *ndev = mod->ndev; 1234 struct net_device_stats *stats = &ndev->stats; 1235 struct ican3_fast_desc desc; 1236 void __iomem *desc_addr; 1237 struct can_frame *cf; 1238 struct sk_buff *skb; 1239 unsigned long flags; 1240 1241 spin_lock_irqsave(&mod->lock, flags); 1242 1243 /* copy the whole descriptor */ 1244 ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); 1245 desc_addr = mod->dpm + ((mod->fastrx_num % 16) * sizeof(desc)); 1246 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 1247 1248 spin_unlock_irqrestore(&mod->lock, flags); 1249 1250 /* check that we actually have a CAN frame */ 1251 if (!(desc.control & DESC_VALID)) 1252 return -ENOBUFS; 1253 1254 /* allocate an skb */ 1255 skb = alloc_can_skb(ndev, &cf); 1256 if (unlikely(skb == NULL)) { 1257 stats->rx_dropped++; 1258 goto err_noalloc; 1259 } 1260 1261 /* convert the ICAN3 frame into Linux CAN format */ 1262 ican3_to_can_frame(mod, &desc, cf); 1263 1264 /* 1265 * If this is an ECHO frame received from the hardware loopback 1266 * feature, use the skb saved in the ECHO stack instead. This allows 1267 * the Linux CAN core to support CAN_RAW_RECV_OWN_MSGS correctly. 1268 * 1269 * Since this is a confirmation of a successfully transmitted packet 1270 * sent from this host, update the transmit statistics. 1271 * 1272 * Also, the netdevice queue needs to be allowed to send packets again. 1273 */ 1274 if (ican3_echo_skb_matches(mod, skb)) { 1275 stats->tx_packets++; 1276 stats->tx_bytes += ican3_get_echo_skb(mod); 1277 kfree_skb(skb); 1278 goto err_noalloc; 1279 } 1280 1281 /* update statistics, receive the skb */ 1282 stats->rx_packets++; 1283 stats->rx_bytes += cf->can_dlc; 1284 netif_receive_skb(skb); 1285 1286err_noalloc: 1287 /* toggle the valid bit and return the descriptor to the ring */ 1288 desc.control ^= DESC_VALID; 1289 1290 spin_lock_irqsave(&mod->lock, flags); 1291 1292 ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); 1293 memcpy_toio(desc_addr, &desc, 1); 1294 1295 /* update the next buffer pointer */ 1296 mod->fastrx_num = (desc.control & DESC_WRAP) ? 0 1297 : (mod->fastrx_num + 1); 1298 1299 /* there are still more buffers to process */ 1300 spin_unlock_irqrestore(&mod->lock, flags); 1301 return 0; 1302} 1303 1304static int ican3_napi(struct napi_struct *napi, int budget) 1305{ 1306 struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi); 1307 unsigned long flags; 1308 int received = 0; 1309 int ret; 1310 1311 /* process all communication messages */ 1312 while (true) { 1313 struct ican3_msg uninitialized_var(msg); 1314 ret = ican3_recv_msg(mod, &msg); 1315 if (ret) 1316 break; 1317 1318 ican3_handle_message(mod, &msg); 1319 } 1320 1321 /* process all CAN frames from the fast interface */ 1322 while (received < budget) { 1323 ret = ican3_recv_skb(mod); 1324 if (ret) 1325 break; 1326 1327 received++; 1328 } 1329 1330 /* We have processed all packets that the adapter had, but it 1331 * was less than our budget, stop polling */ 1332 if (received < budget) 1333 napi_complete(napi); 1334 1335 spin_lock_irqsave(&mod->lock, flags); 1336 1337 /* Wake up the transmit queue if necessary */ 1338 if (netif_queue_stopped(mod->ndev) && ican3_txok(mod)) 1339 netif_wake_queue(mod->ndev); 1340 1341 spin_unlock_irqrestore(&mod->lock, flags); 1342 1343 /* re-enable interrupt generation */ 1344 iowrite8(1 << mod->num, &mod->ctrl->int_enable); 1345 return received; 1346} 1347 1348static irqreturn_t ican3_irq(int irq, void *dev_id) 1349{ 1350 struct ican3_dev *mod = dev_id; 1351 u8 stat; 1352 1353 /* 1354 * The interrupt status register on this device reports interrupts 1355 * as zeroes instead of using ones like most other devices 1356 */ 1357 stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num); 1358 if (stat == (1 << mod->num)) 1359 return IRQ_NONE; 1360 1361 /* clear the MODULbus interrupt from the microcontroller */ 1362 ioread8(&mod->dpmctrl->interrupt); 1363 1364 /* disable interrupt generation, schedule the NAPI poller */ 1365 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1366 napi_schedule(&mod->napi); 1367 return IRQ_HANDLED; 1368} 1369 1370/* 1371 * Firmware reset, startup, and shutdown 1372 */ 1373 1374/* 1375 * Reset an ICAN module to its power-on state 1376 * 1377 * CONTEXT: no network device registered 1378 */ 1379static int ican3_reset_module(struct ican3_dev *mod) 1380{ 1381 unsigned long start; 1382 u8 runold, runnew; 1383 1384 /* disable interrupts so no more work is scheduled */ 1385 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1386 1387 /* the first unallocated page in the DPM is #9 */ 1388 mod->free_page = DPM_FREE_START; 1389 1390 ican3_set_page(mod, QUEUE_OLD_CONTROL); 1391 runold = ioread8(mod->dpm + TARGET_RUNNING); 1392 1393 /* reset the module */ 1394 iowrite8(0x00, &mod->dpmctrl->hwreset); 1395 1396 /* wait until the module has finished resetting and is running */ 1397 start = jiffies; 1398 do { 1399 ican3_set_page(mod, QUEUE_OLD_CONTROL); 1400 runnew = ioread8(mod->dpm + TARGET_RUNNING); 1401 if (runnew == (runold ^ 0xff)) 1402 return 0; 1403 1404 msleep(10); 1405 } while (time_before(jiffies, start + HZ / 4)); 1406 1407 netdev_err(mod->ndev, "failed to reset CAN module\n"); 1408 return -ETIMEDOUT; 1409} 1410 1411static void ican3_shutdown_module(struct ican3_dev *mod) 1412{ 1413 ican3_msg_disconnect(mod); 1414 ican3_reset_module(mod); 1415} 1416 1417/* 1418 * Startup an ICAN module, bringing it into fast mode 1419 */ 1420static int ican3_startup_module(struct ican3_dev *mod) 1421{ 1422 int ret; 1423 1424 ret = ican3_reset_module(mod); 1425 if (ret) { 1426 netdev_err(mod->ndev, "unable to reset module\n"); 1427 return ret; 1428 } 1429 1430 /* re-enable interrupts so we can send messages */ 1431 iowrite8(1 << mod->num, &mod->ctrl->int_enable); 1432 1433 ret = ican3_msg_connect(mod); 1434 if (ret) { 1435 netdev_err(mod->ndev, "unable to connect to module\n"); 1436 return ret; 1437 } 1438 1439 ican3_init_new_host_interface(mod); 1440 ret = ican3_msg_newhostif(mod); 1441 if (ret) { 1442 netdev_err(mod->ndev, "unable to switch to new-style interface\n"); 1443 return ret; 1444 } 1445 1446 /* default to "termination on" */ 1447 ret = ican3_set_termination(mod, true); 1448 if (ret) { 1449 netdev_err(mod->ndev, "unable to enable termination\n"); 1450 return ret; 1451 } 1452 1453 /* default to "bus errors enabled" */ 1454 ret = ican3_set_buserror(mod, 1); 1455 if (ret) { 1456 netdev_err(mod->ndev, "unable to set bus-error\n"); 1457 return ret; 1458 } 1459 1460 ican3_init_fast_host_interface(mod); 1461 ret = ican3_msg_fasthostif(mod); 1462 if (ret) { 1463 netdev_err(mod->ndev, "unable to switch to fast host interface\n"); 1464 return ret; 1465 } 1466 1467 ret = ican3_set_id_filter(mod, true); 1468 if (ret) { 1469 netdev_err(mod->ndev, "unable to set acceptance filter\n"); 1470 return ret; 1471 } 1472 1473 return 0; 1474} 1475 1476/* 1477 * CAN Network Device 1478 */ 1479 1480static int ican3_open(struct net_device *ndev) 1481{ 1482 struct ican3_dev *mod = netdev_priv(ndev); 1483 int ret; 1484 1485 /* open the CAN layer */ 1486 ret = open_candev(ndev); 1487 if (ret) { 1488 netdev_err(mod->ndev, "unable to start CAN layer\n"); 1489 return ret; 1490 } 1491 1492 /* bring the bus online */ 1493 ret = ican3_set_bus_state(mod, true); 1494 if (ret) { 1495 netdev_err(mod->ndev, "unable to set bus-on\n"); 1496 close_candev(ndev); 1497 return ret; 1498 } 1499 1500 /* start up the network device */ 1501 mod->can.state = CAN_STATE_ERROR_ACTIVE; 1502 netif_start_queue(ndev); 1503 1504 return 0; 1505} 1506 1507static int ican3_stop(struct net_device *ndev) 1508{ 1509 struct ican3_dev *mod = netdev_priv(ndev); 1510 int ret; 1511 1512 /* stop the network device xmit routine */ 1513 netif_stop_queue(ndev); 1514 mod->can.state = CAN_STATE_STOPPED; 1515 1516 /* bring the bus offline, stop receiving packets */ 1517 ret = ican3_set_bus_state(mod, false); 1518 if (ret) { 1519 netdev_err(mod->ndev, "unable to set bus-off\n"); 1520 return ret; 1521 } 1522 1523 /* drop all outstanding echo skbs */ 1524 skb_queue_purge(&mod->echoq); 1525 1526 /* close the CAN layer */ 1527 close_candev(ndev); 1528 return 0; 1529} 1530 1531static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev) 1532{ 1533 struct ican3_dev *mod = netdev_priv(ndev); 1534 struct can_frame *cf = (struct can_frame *)skb->data; 1535 struct ican3_fast_desc desc; 1536 void __iomem *desc_addr; 1537 unsigned long flags; 1538 1539 if (can_dropped_invalid_skb(ndev, skb)) 1540 return NETDEV_TX_OK; 1541 1542 spin_lock_irqsave(&mod->lock, flags); 1543 1544 /* check that we can actually transmit */ 1545 if (!ican3_txok(mod)) { 1546 netdev_err(mod->ndev, "BUG: no free descriptors\n"); 1547 spin_unlock_irqrestore(&mod->lock, flags); 1548 return NETDEV_TX_BUSY; 1549 } 1550 1551 /* copy the control bits of the descriptor */ 1552 ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); 1553 desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc)); 1554 memset(&desc, 0, sizeof(desc)); 1555 memcpy_fromio(&desc, desc_addr, 1); 1556 1557 /* convert the Linux CAN frame into ICAN3 format */ 1558 can_frame_to_ican3(mod, cf, &desc); 1559 1560 /* 1561 * This hardware doesn't have TX-done notifications, so we'll try and 1562 * emulate it the best we can using ECHO skbs. Add the skb to the ECHO 1563 * stack. Upon packet reception, check if the ECHO skb and received 1564 * skb match, and use that to wake the queue. 1565 */ 1566 ican3_put_echo_skb(mod, skb); 1567 1568 /* 1569 * the programming manual says that you must set the IVALID bit, then 1570 * interrupt, then set the valid bit. Quite weird, but it seems to be 1571 * required for this to work 1572 */ 1573 desc.control |= DESC_IVALID; 1574 memcpy_toio(desc_addr, &desc, sizeof(desc)); 1575 1576 /* generate a MODULbus interrupt to the microcontroller */ 1577 iowrite8(0x01, &mod->dpmctrl->interrupt); 1578 1579 desc.control ^= DESC_VALID; 1580 memcpy_toio(desc_addr, &desc, sizeof(desc)); 1581 1582 /* update the next buffer pointer */ 1583 mod->fasttx_num = (desc.control & DESC_WRAP) ? 0 1584 : (mod->fasttx_num + 1); 1585 1586 /* if there is no free descriptor space, stop the transmit queue */ 1587 if (!ican3_txok(mod)) 1588 netif_stop_queue(ndev); 1589 1590 spin_unlock_irqrestore(&mod->lock, flags); 1591 return NETDEV_TX_OK; 1592} 1593 1594static const struct net_device_ops ican3_netdev_ops = { 1595 .ndo_open = ican3_open, 1596 .ndo_stop = ican3_stop, 1597 .ndo_start_xmit = ican3_xmit, 1598 .ndo_change_mtu = can_change_mtu, 1599}; 1600 1601/* 1602 * Low-level CAN Device 1603 */ 1604 1605/* This structure was stolen from drivers/net/can/sja1000/sja1000.c */ 1606static const struct can_bittiming_const ican3_bittiming_const = { 1607 .name = DRV_NAME, 1608 .tseg1_min = 1, 1609 .tseg1_max = 16, 1610 .tseg2_min = 1, 1611 .tseg2_max = 8, 1612 .sjw_max = 4, 1613 .brp_min = 1, 1614 .brp_max = 64, 1615 .brp_inc = 1, 1616}; 1617 1618/* 1619 * This routine was stolen from drivers/net/can/sja1000/sja1000.c 1620 * 1621 * The bittiming register command for the ICAN3 just sets the bit timing 1622 * registers on the SJA1000 chip directly 1623 */ 1624static int ican3_set_bittiming(struct net_device *ndev) 1625{ 1626 struct ican3_dev *mod = netdev_priv(ndev); 1627 struct can_bittiming *bt = &mod->can.bittiming; 1628 struct ican3_msg msg; 1629 u8 btr0, btr1; 1630 1631 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 1632 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 1633 (((bt->phase_seg2 - 1) & 0x7) << 4); 1634 if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 1635 btr1 |= 0x80; 1636 1637 memset(&msg, 0, sizeof(msg)); 1638 msg.spec = MSG_CBTRREQ; 1639 msg.len = cpu_to_le16(4); 1640 msg.data[0] = 0x00; 1641 msg.data[1] = 0x00; 1642 msg.data[2] = btr0; 1643 msg.data[3] = btr1; 1644 1645 return ican3_send_msg(mod, &msg); 1646} 1647 1648static int ican3_set_mode(struct net_device *ndev, enum can_mode mode) 1649{ 1650 struct ican3_dev *mod = netdev_priv(ndev); 1651 int ret; 1652 1653 if (mode != CAN_MODE_START) 1654 return -ENOTSUPP; 1655 1656 /* bring the bus online */ 1657 ret = ican3_set_bus_state(mod, true); 1658 if (ret) { 1659 netdev_err(ndev, "unable to set bus-on\n"); 1660 return ret; 1661 } 1662 1663 /* start up the network device */ 1664 mod->can.state = CAN_STATE_ERROR_ACTIVE; 1665 1666 if (netif_queue_stopped(ndev)) 1667 netif_wake_queue(ndev); 1668 1669 return 0; 1670} 1671 1672static int ican3_get_berr_counter(const struct net_device *ndev, 1673 struct can_berr_counter *bec) 1674{ 1675 struct ican3_dev *mod = netdev_priv(ndev); 1676 int ret; 1677 1678 ret = ican3_send_inquiry(mod, INQUIRY_STATUS); 1679 if (ret) 1680 return ret; 1681 1682 if (!wait_for_completion_timeout(&mod->buserror_comp, HZ)) { 1683 netdev_info(mod->ndev, "%s timed out\n", __func__); 1684 return -ETIMEDOUT; 1685 } 1686 1687 bec->rxerr = mod->bec.rxerr; 1688 bec->txerr = mod->bec.txerr; 1689 return 0; 1690} 1691 1692/* 1693 * Sysfs Attributes 1694 */ 1695 1696static ssize_t ican3_sysfs_show_term(struct device *dev, 1697 struct device_attribute *attr, 1698 char *buf) 1699{ 1700 struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); 1701 int ret; 1702 1703 ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION); 1704 if (ret) 1705 return ret; 1706 1707 if (!wait_for_completion_timeout(&mod->termination_comp, HZ)) { 1708 netdev_info(mod->ndev, "%s timed out\n", __func__); 1709 return -ETIMEDOUT; 1710 } 1711 1712 return snprintf(buf, PAGE_SIZE, "%u\n", mod->termination_enabled); 1713} 1714 1715static ssize_t ican3_sysfs_set_term(struct device *dev, 1716 struct device_attribute *attr, 1717 const char *buf, size_t count) 1718{ 1719 struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); 1720 unsigned long enable; 1721 int ret; 1722 1723 if (kstrtoul(buf, 0, &enable)) 1724 return -EINVAL; 1725 1726 ret = ican3_set_termination(mod, enable); 1727 if (ret) 1728 return ret; 1729 1730 return count; 1731} 1732 1733static DEVICE_ATTR(termination, S_IWUSR | S_IRUGO, ican3_sysfs_show_term, 1734 ican3_sysfs_set_term); 1735 1736static struct attribute *ican3_sysfs_attrs[] = { 1737 &dev_attr_termination.attr, 1738 NULL, 1739}; 1740 1741static struct attribute_group ican3_sysfs_attr_group = { 1742 .attrs = ican3_sysfs_attrs, 1743}; 1744 1745/* 1746 * PCI Subsystem 1747 */ 1748 1749static int ican3_probe(struct platform_device *pdev) 1750{ 1751 struct janz_platform_data *pdata; 1752 struct net_device *ndev; 1753 struct ican3_dev *mod; 1754 struct resource *res; 1755 struct device *dev; 1756 int ret; 1757 1758 pdata = dev_get_platdata(&pdev->dev); 1759 if (!pdata) 1760 return -ENXIO; 1761 1762 dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno); 1763 1764 /* save the struct device for printing */ 1765 dev = &pdev->dev; 1766 1767 /* allocate the CAN device and private data */ 1768 ndev = alloc_candev(sizeof(*mod), 0); 1769 if (!ndev) { 1770 dev_err(dev, "unable to allocate CANdev\n"); 1771 ret = -ENOMEM; 1772 goto out_return; 1773 } 1774 1775 platform_set_drvdata(pdev, ndev); 1776 mod = netdev_priv(ndev); 1777 mod->ndev = ndev; 1778 mod->num = pdata->modno; 1779 netif_napi_add(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS); 1780 skb_queue_head_init(&mod->echoq); 1781 spin_lock_init(&mod->lock); 1782 init_completion(&mod->termination_comp); 1783 init_completion(&mod->buserror_comp); 1784 1785 /* setup device-specific sysfs attributes */ 1786 ndev->sysfs_groups[0] = &ican3_sysfs_attr_group; 1787 1788 /* the first unallocated page in the DPM is 9 */ 1789 mod->free_page = DPM_FREE_START; 1790 1791 ndev->netdev_ops = &ican3_netdev_ops; 1792 ndev->flags |= IFF_ECHO; 1793 SET_NETDEV_DEV(ndev, &pdev->dev); 1794 1795 mod->can.clock.freq = ICAN3_CAN_CLOCK; 1796 mod->can.bittiming_const = &ican3_bittiming_const; 1797 mod->can.do_set_bittiming = ican3_set_bittiming; 1798 mod->can.do_set_mode = ican3_set_mode; 1799 mod->can.do_get_berr_counter = ican3_get_berr_counter; 1800 mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES 1801 | CAN_CTRLMODE_BERR_REPORTING 1802 | CAN_CTRLMODE_ONE_SHOT; 1803 1804 /* find our IRQ number */ 1805 mod->irq = platform_get_irq(pdev, 0); 1806 if (mod->irq < 0) { 1807 dev_err(dev, "IRQ line not found\n"); 1808 ret = -ENODEV; 1809 goto out_free_ndev; 1810 } 1811 1812 ndev->irq = mod->irq; 1813 1814 /* get access to the MODULbus registers for this module */ 1815 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1816 if (!res) { 1817 dev_err(dev, "MODULbus registers not found\n"); 1818 ret = -ENODEV; 1819 goto out_free_ndev; 1820 } 1821 1822 mod->dpm = ioremap(res->start, resource_size(res)); 1823 if (!mod->dpm) { 1824 dev_err(dev, "MODULbus registers not ioremap\n"); 1825 ret = -ENOMEM; 1826 goto out_free_ndev; 1827 } 1828 1829 mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE; 1830 1831 /* get access to the control registers for this module */ 1832 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 1833 if (!res) { 1834 dev_err(dev, "CONTROL registers not found\n"); 1835 ret = -ENODEV; 1836 goto out_iounmap_dpm; 1837 } 1838 1839 mod->ctrl = ioremap(res->start, resource_size(res)); 1840 if (!mod->ctrl) { 1841 dev_err(dev, "CONTROL registers not ioremap\n"); 1842 ret = -ENOMEM; 1843 goto out_iounmap_dpm; 1844 } 1845 1846 /* disable our IRQ, then hookup the IRQ handler */ 1847 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1848 ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod); 1849 if (ret) { 1850 dev_err(dev, "unable to request IRQ\n"); 1851 goto out_iounmap_ctrl; 1852 } 1853 1854 /* reset and initialize the CAN controller into fast mode */ 1855 napi_enable(&mod->napi); 1856 ret = ican3_startup_module(mod); 1857 if (ret) { 1858 dev_err(dev, "%s: unable to start CANdev\n", __func__); 1859 goto out_free_irq; 1860 } 1861 1862 /* register with the Linux CAN layer */ 1863 ret = register_candev(ndev); 1864 if (ret) { 1865 dev_err(dev, "%s: unable to register CANdev\n", __func__); 1866 goto out_free_irq; 1867 } 1868 1869 dev_info(dev, "module %d: registered CAN device\n", pdata->modno); 1870 return 0; 1871 1872out_free_irq: 1873 napi_disable(&mod->napi); 1874 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1875 free_irq(mod->irq, mod); 1876out_iounmap_ctrl: 1877 iounmap(mod->ctrl); 1878out_iounmap_dpm: 1879 iounmap(mod->dpm); 1880out_free_ndev: 1881 free_candev(ndev); 1882out_return: 1883 return ret; 1884} 1885 1886static int ican3_remove(struct platform_device *pdev) 1887{ 1888 struct net_device *ndev = platform_get_drvdata(pdev); 1889 struct ican3_dev *mod = netdev_priv(ndev); 1890 1891 /* unregister the netdevice, stop interrupts */ 1892 unregister_netdev(ndev); 1893 napi_disable(&mod->napi); 1894 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1895 free_irq(mod->irq, mod); 1896 1897 /* put the module into reset */ 1898 ican3_shutdown_module(mod); 1899 1900 /* unmap all registers */ 1901 iounmap(mod->ctrl); 1902 iounmap(mod->dpm); 1903 1904 free_candev(ndev); 1905 1906 return 0; 1907} 1908 1909static struct platform_driver ican3_driver = { 1910 .driver = { 1911 .name = DRV_NAME, 1912 }, 1913 .probe = ican3_probe, 1914 .remove = ican3_remove, 1915}; 1916 1917module_platform_driver(ican3_driver); 1918 1919MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); 1920MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver"); 1921MODULE_LICENSE("GPL"); 1922MODULE_ALIAS("platform:janz-ican3"); 1923