janz-ican3.c revision 73615c8669ef1c497c942cae0d5079b95824332a
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/error.h> 22 23#include <linux/mfd/janz.h> 24#include <asm/io.h> 25 26/* the DPM has 64k of memory, organized into 256x 256 byte pages */ 27#define DPM_NUM_PAGES 256 28#define DPM_PAGE_SIZE 256 29#define DPM_PAGE_ADDR(p) ((p) * DPM_PAGE_SIZE) 30 31/* JANZ ICAN3 "old-style" host interface queue page numbers */ 32#define QUEUE_OLD_CONTROL 0 33#define QUEUE_OLD_RB0 1 34#define QUEUE_OLD_RB1 2 35#define QUEUE_OLD_WB0 3 36#define QUEUE_OLD_WB1 4 37 38/* Janz ICAN3 "old-style" host interface control registers */ 39#define MSYNC_PEER 0x00 /* ICAN only */ 40#define MSYNC_LOCL 0x01 /* host only */ 41#define TARGET_RUNNING 0x02 42 43#define MSYNC_RB0 0x01 44#define MSYNC_RB1 0x02 45#define MSYNC_RBLW 0x04 46#define MSYNC_RB_MASK (MSYNC_RB0 | MSYNC_RB1) 47 48#define MSYNC_WB0 0x10 49#define MSYNC_WB1 0x20 50#define MSYNC_WBLW 0x40 51#define MSYNC_WB_MASK (MSYNC_WB0 | MSYNC_WB1) 52 53/* Janz ICAN3 "new-style" host interface queue page numbers */ 54#define QUEUE_TOHOST 5 55#define QUEUE_FROMHOST_MID 6 56#define QUEUE_FROMHOST_HIGH 7 57#define QUEUE_FROMHOST_LOW 8 58 59/* The first free page in the DPM is #9 */ 60#define DPM_FREE_START 9 61 62/* Janz ICAN3 "new-style" and "fast" host interface descriptor flags */ 63#define DESC_VALID 0x80 64#define DESC_WRAP 0x40 65#define DESC_INTERRUPT 0x20 66#define DESC_IVALID 0x10 67#define DESC_LEN(len) (len) 68 69/* Janz ICAN3 Firmware Messages */ 70#define MSG_CONNECTI 0x02 71#define MSG_DISCONNECT 0x03 72#define MSG_IDVERS 0x04 73#define MSG_MSGLOST 0x05 74#define MSG_NEWHOSTIF 0x08 75#define MSG_INQUIRY 0x0a 76#define MSG_SETAFILMASK 0x10 77#define MSG_INITFDPMQUEUE 0x11 78#define MSG_HWCONF 0x12 79#define MSG_FMSGLOST 0x15 80#define MSG_CEVTIND 0x37 81#define MSG_CBTRREQ 0x41 82#define MSG_COFFREQ 0x42 83#define MSG_CONREQ 0x43 84#define MSG_CCONFREQ 0x47 85 86/* 87 * Janz ICAN3 CAN Inquiry Message Types 88 * 89 * NOTE: there appears to be a firmware bug here. You must send 90 * NOTE: INQUIRY_STATUS and expect to receive an INQUIRY_EXTENDED 91 * NOTE: response. The controller never responds to a message with 92 * NOTE: the INQUIRY_EXTENDED subspec :( 93 */ 94#define INQUIRY_STATUS 0x00 95#define INQUIRY_TERMINATION 0x01 96#define INQUIRY_EXTENDED 0x04 97 98/* Janz ICAN3 CAN Set Acceptance Filter Mask Message Types */ 99#define SETAFILMASK_REJECT 0x00 100#define SETAFILMASK_FASTIF 0x02 101 102/* Janz ICAN3 CAN Hardware Configuration Message Types */ 103#define HWCONF_TERMINATE_ON 0x01 104#define HWCONF_TERMINATE_OFF 0x00 105 106/* Janz ICAN3 CAN Event Indication Message Types */ 107#define CEVTIND_EI 0x01 108#define CEVTIND_DOI 0x02 109#define CEVTIND_LOST 0x04 110#define CEVTIND_FULL 0x08 111#define CEVTIND_BEI 0x10 112 113#define CEVTIND_CHIP_SJA1000 0x02 114 115#define ICAN3_BUSERR_QUOTA_MAX 255 116 117/* Janz ICAN3 CAN Frame Conversion */ 118#define ICAN3_SNGL 0x02 119#define ICAN3_ECHO 0x10 120#define ICAN3_EFF_RTR 0x40 121#define ICAN3_SFF_RTR 0x10 122#define ICAN3_EFF 0x80 123 124#define ICAN3_CAN_TYPE_MASK 0x0f 125#define ICAN3_CAN_TYPE_SFF 0x00 126#define ICAN3_CAN_TYPE_EFF 0x01 127 128#define ICAN3_CAN_DLC_MASK 0x0f 129 130/* 131 * SJA1000 Status and Error Register Definitions 132 * 133 * Copied from drivers/net/can/sja1000/sja1000.h 134 */ 135 136/* status register content */ 137#define SR_BS 0x80 138#define SR_ES 0x40 139#define SR_TS 0x20 140#define SR_RS 0x10 141#define SR_TCS 0x08 142#define SR_TBS 0x04 143#define SR_DOS 0x02 144#define SR_RBS 0x01 145 146#define SR_CRIT (SR_BS|SR_ES) 147 148/* ECC register */ 149#define ECC_SEG 0x1F 150#define ECC_DIR 0x20 151#define ECC_ERR 6 152#define ECC_BIT 0x00 153#define ECC_FORM 0x40 154#define ECC_STUFF 0x80 155#define ECC_MASK 0xc0 156 157/* Number of buffers for use in the "new-style" host interface */ 158#define ICAN3_NEW_BUFFERS 16 159 160/* Number of buffers for use in the "fast" host interface */ 161#define ICAN3_TX_BUFFERS 512 162#define ICAN3_RX_BUFFERS 1024 163 164/* SJA1000 Clock Input */ 165#define ICAN3_CAN_CLOCK 8000000 166 167/* Driver Name */ 168#define DRV_NAME "janz-ican3" 169 170/* DPM Control Registers -- starts at offset 0x100 in the MODULbus registers */ 171struct ican3_dpm_control { 172 /* window address register */ 173 u8 window_address; 174 u8 unused1; 175 176 /* 177 * Read access: clear interrupt from microcontroller 178 * Write access: send interrupt to microcontroller 179 */ 180 u8 interrupt; 181 u8 unused2; 182 183 /* write-only: reset all hardware on the module */ 184 u8 hwreset; 185 u8 unused3; 186 187 /* write-only: generate an interrupt to the TPU */ 188 u8 tpuinterrupt; 189}; 190 191struct ican3_dev { 192 193 /* must be the first member */ 194 struct can_priv can; 195 196 /* CAN network device */ 197 struct net_device *ndev; 198 struct napi_struct napi; 199 200 /* Device for printing */ 201 struct device *dev; 202 203 /* module number */ 204 unsigned int num; 205 206 /* base address of registers and IRQ */ 207 struct janz_cmodio_onboard_regs __iomem *ctrl; 208 struct ican3_dpm_control __iomem *dpmctrl; 209 void __iomem *dpm; 210 int irq; 211 212 /* CAN bus termination status */ 213 struct completion termination_comp; 214 bool termination_enabled; 215 216 /* CAN bus error status registers */ 217 struct completion buserror_comp; 218 struct can_berr_counter bec; 219 220 /* old and new style host interface */ 221 unsigned int iftype; 222 223 /* queue for echo packets */ 224 struct sk_buff_head echoq; 225 226 /* 227 * Any function which changes the current DPM page must hold this 228 * lock while it is performing data accesses. This ensures that the 229 * function will not be preempted and end up reading data from a 230 * different DPM page than it expects. 231 */ 232 spinlock_t lock; 233 234 /* new host interface */ 235 unsigned int rx_int; 236 unsigned int rx_num; 237 unsigned int tx_num; 238 239 /* fast host interface */ 240 unsigned int fastrx_start; 241 unsigned int fastrx_num; 242 unsigned int fasttx_start; 243 unsigned int fasttx_num; 244 245 /* first free DPM page */ 246 unsigned int free_page; 247}; 248 249struct ican3_msg { 250 u8 control; 251 u8 spec; 252 __le16 len; 253 u8 data[252]; 254}; 255 256struct ican3_new_desc { 257 u8 control; 258 u8 pointer; 259}; 260 261struct ican3_fast_desc { 262 u8 control; 263 u8 command; 264 u8 data[14]; 265}; 266 267/* write to the window basic address register */ 268static inline void ican3_set_page(struct ican3_dev *mod, unsigned int page) 269{ 270 BUG_ON(page >= DPM_NUM_PAGES); 271 iowrite8(page, &mod->dpmctrl->window_address); 272} 273 274/* 275 * ICAN3 "old-style" host interface 276 */ 277 278/* 279 * Receive a message from the ICAN3 "old-style" firmware interface 280 * 281 * LOCKING: must hold mod->lock 282 * 283 * returns 0 on success, -ENOMEM when no message exists 284 */ 285static int ican3_old_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 286{ 287 unsigned int mbox, mbox_page; 288 u8 locl, peer, xord; 289 290 /* get the MSYNC registers */ 291 ican3_set_page(mod, QUEUE_OLD_CONTROL); 292 peer = ioread8(mod->dpm + MSYNC_PEER); 293 locl = ioread8(mod->dpm + MSYNC_LOCL); 294 xord = locl ^ peer; 295 296 if ((xord & MSYNC_RB_MASK) == 0x00) { 297 dev_dbg(mod->dev, "no mbox for reading\n"); 298 return -ENOMEM; 299 } 300 301 /* find the first free mbox to read */ 302 if ((xord & MSYNC_RB_MASK) == MSYNC_RB_MASK) 303 mbox = (xord & MSYNC_RBLW) ? MSYNC_RB0 : MSYNC_RB1; 304 else 305 mbox = (xord & MSYNC_RB0) ? MSYNC_RB0 : MSYNC_RB1; 306 307 /* copy the message */ 308 mbox_page = (mbox == MSYNC_RB0) ? QUEUE_OLD_RB0 : QUEUE_OLD_RB1; 309 ican3_set_page(mod, mbox_page); 310 memcpy_fromio(msg, mod->dpm, sizeof(*msg)); 311 312 /* 313 * notify the firmware that the read buffer is available 314 * for it to fill again 315 */ 316 locl ^= mbox; 317 318 ican3_set_page(mod, QUEUE_OLD_CONTROL); 319 iowrite8(locl, mod->dpm + MSYNC_LOCL); 320 return 0; 321} 322 323/* 324 * Send a message through the "old-style" firmware interface 325 * 326 * LOCKING: must hold mod->lock 327 * 328 * returns 0 on success, -ENOMEM when no free space exists 329 */ 330static int ican3_old_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 331{ 332 unsigned int mbox, mbox_page; 333 u8 locl, peer, xord; 334 335 /* get the MSYNC registers */ 336 ican3_set_page(mod, QUEUE_OLD_CONTROL); 337 peer = ioread8(mod->dpm + MSYNC_PEER); 338 locl = ioread8(mod->dpm + MSYNC_LOCL); 339 xord = locl ^ peer; 340 341 if ((xord & MSYNC_WB_MASK) == MSYNC_WB_MASK) { 342 dev_err(mod->dev, "no mbox for writing\n"); 343 return -ENOMEM; 344 } 345 346 /* calculate a free mbox to use */ 347 mbox = (xord & MSYNC_WB0) ? MSYNC_WB1 : MSYNC_WB0; 348 349 /* copy the message to the DPM */ 350 mbox_page = (mbox == MSYNC_WB0) ? QUEUE_OLD_WB0 : QUEUE_OLD_WB1; 351 ican3_set_page(mod, mbox_page); 352 memcpy_toio(mod->dpm, msg, sizeof(*msg)); 353 354 locl ^= mbox; 355 if (mbox == MSYNC_WB1) 356 locl |= MSYNC_WBLW; 357 358 ican3_set_page(mod, QUEUE_OLD_CONTROL); 359 iowrite8(locl, mod->dpm + MSYNC_LOCL); 360 return 0; 361} 362 363/* 364 * ICAN3 "new-style" Host Interface Setup 365 */ 366 367static void ican3_init_new_host_interface(struct ican3_dev *mod) 368{ 369 struct ican3_new_desc desc; 370 unsigned long flags; 371 void __iomem *dst; 372 int i; 373 374 spin_lock_irqsave(&mod->lock, flags); 375 376 /* setup the internal datastructures for RX */ 377 mod->rx_num = 0; 378 mod->rx_int = 0; 379 380 /* tohost queue descriptors are in page 5 */ 381 ican3_set_page(mod, QUEUE_TOHOST); 382 dst = mod->dpm; 383 384 /* initialize the tohost (rx) queue descriptors: pages 9-24 */ 385 for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { 386 desc.control = DESC_INTERRUPT | DESC_LEN(1); /* I L=1 */ 387 desc.pointer = mod->free_page; 388 389 /* set wrap flag on last buffer */ 390 if (i == ICAN3_NEW_BUFFERS - 1) 391 desc.control |= DESC_WRAP; 392 393 memcpy_toio(dst, &desc, sizeof(desc)); 394 dst += sizeof(desc); 395 mod->free_page++; 396 } 397 398 /* fromhost (tx) mid queue descriptors are in page 6 */ 399 ican3_set_page(mod, QUEUE_FROMHOST_MID); 400 dst = mod->dpm; 401 402 /* setup the internal datastructures for TX */ 403 mod->tx_num = 0; 404 405 /* initialize the fromhost mid queue descriptors: pages 25-40 */ 406 for (i = 0; i < ICAN3_NEW_BUFFERS; i++) { 407 desc.control = DESC_VALID | DESC_LEN(1); /* V L=1 */ 408 desc.pointer = mod->free_page; 409 410 /* set wrap flag on last buffer */ 411 if (i == ICAN3_NEW_BUFFERS - 1) 412 desc.control |= DESC_WRAP; 413 414 memcpy_toio(dst, &desc, sizeof(desc)); 415 dst += sizeof(desc); 416 mod->free_page++; 417 } 418 419 /* fromhost hi queue descriptors are in page 7 */ 420 ican3_set_page(mod, QUEUE_FROMHOST_HIGH); 421 dst = mod->dpm; 422 423 /* initialize only a single buffer in the fromhost hi queue (unused) */ 424 desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ 425 desc.pointer = mod->free_page; 426 memcpy_toio(dst, &desc, sizeof(desc)); 427 mod->free_page++; 428 429 /* fromhost low queue descriptors are in page 8 */ 430 ican3_set_page(mod, QUEUE_FROMHOST_LOW); 431 dst = mod->dpm; 432 433 /* initialize only a single buffer in the fromhost low queue (unused) */ 434 desc.control = DESC_VALID | DESC_WRAP | DESC_LEN(1); /* VW L=1 */ 435 desc.pointer = mod->free_page; 436 memcpy_toio(dst, &desc, sizeof(desc)); 437 mod->free_page++; 438 439 spin_unlock_irqrestore(&mod->lock, flags); 440} 441 442/* 443 * ICAN3 Fast Host Interface Setup 444 */ 445 446static void ican3_init_fast_host_interface(struct ican3_dev *mod) 447{ 448 struct ican3_fast_desc desc; 449 unsigned long flags; 450 unsigned int addr; 451 void __iomem *dst; 452 int i; 453 454 spin_lock_irqsave(&mod->lock, flags); 455 456 /* save the start recv page */ 457 mod->fastrx_start = mod->free_page; 458 mod->fastrx_num = 0; 459 460 /* build a single fast tohost queue descriptor */ 461 memset(&desc, 0, sizeof(desc)); 462 desc.control = 0x00; 463 desc.command = 1; 464 465 /* build the tohost queue descriptor ring in memory */ 466 addr = 0; 467 for (i = 0; i < ICAN3_RX_BUFFERS; i++) { 468 469 /* set the wrap bit on the last buffer */ 470 if (i == ICAN3_RX_BUFFERS - 1) 471 desc.control |= DESC_WRAP; 472 473 /* switch to the correct page */ 474 ican3_set_page(mod, mod->free_page); 475 476 /* copy the descriptor to the DPM */ 477 dst = mod->dpm + addr; 478 memcpy_toio(dst, &desc, sizeof(desc)); 479 addr += sizeof(desc); 480 481 /* move to the next page if necessary */ 482 if (addr >= DPM_PAGE_SIZE) { 483 addr = 0; 484 mod->free_page++; 485 } 486 } 487 488 /* make sure we page-align the next queue */ 489 if (addr != 0) 490 mod->free_page++; 491 492 /* save the start xmit page */ 493 mod->fasttx_start = mod->free_page; 494 mod->fasttx_num = 0; 495 496 /* build a single fast fromhost queue descriptor */ 497 memset(&desc, 0, sizeof(desc)); 498 desc.control = DESC_VALID; 499 desc.command = 1; 500 501 /* build the fromhost queue descriptor ring in memory */ 502 addr = 0; 503 for (i = 0; i < ICAN3_TX_BUFFERS; i++) { 504 505 /* set the wrap bit on the last buffer */ 506 if (i == ICAN3_TX_BUFFERS - 1) 507 desc.control |= DESC_WRAP; 508 509 /* switch to the correct page */ 510 ican3_set_page(mod, mod->free_page); 511 512 /* copy the descriptor to the DPM */ 513 dst = mod->dpm + addr; 514 memcpy_toio(dst, &desc, sizeof(desc)); 515 addr += sizeof(desc); 516 517 /* move to the next page if necessary */ 518 if (addr >= DPM_PAGE_SIZE) { 519 addr = 0; 520 mod->free_page++; 521 } 522 } 523 524 spin_unlock_irqrestore(&mod->lock, flags); 525} 526 527/* 528 * ICAN3 "new-style" Host Interface Message Helpers 529 */ 530 531/* 532 * LOCKING: must hold mod->lock 533 */ 534static int ican3_new_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 535{ 536 struct ican3_new_desc desc; 537 void __iomem *desc_addr = mod->dpm + (mod->tx_num * sizeof(desc)); 538 539 /* switch to the fromhost mid queue, and read the buffer descriptor */ 540 ican3_set_page(mod, QUEUE_FROMHOST_MID); 541 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 542 543 if (!(desc.control & DESC_VALID)) { 544 dev_dbg(mod->dev, "%s: no free buffers\n", __func__); 545 return -ENOMEM; 546 } 547 548 /* switch to the data page, copy the data */ 549 ican3_set_page(mod, desc.pointer); 550 memcpy_toio(mod->dpm, msg, sizeof(*msg)); 551 552 /* switch back to the descriptor, set the valid bit, write it back */ 553 ican3_set_page(mod, QUEUE_FROMHOST_MID); 554 desc.control ^= DESC_VALID; 555 memcpy_toio(desc_addr, &desc, sizeof(desc)); 556 557 /* update the tx number */ 558 mod->tx_num = (desc.control & DESC_WRAP) ? 0 : (mod->tx_num + 1); 559 return 0; 560} 561 562/* 563 * LOCKING: must hold mod->lock 564 */ 565static int ican3_new_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 566{ 567 struct ican3_new_desc desc; 568 void __iomem *desc_addr = mod->dpm + (mod->rx_num * sizeof(desc)); 569 570 /* switch to the tohost queue, and read the buffer descriptor */ 571 ican3_set_page(mod, QUEUE_TOHOST); 572 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 573 574 if (!(desc.control & DESC_VALID)) { 575 dev_dbg(mod->dev, "%s: no buffers to recv\n", __func__); 576 return -ENOMEM; 577 } 578 579 /* switch to the data page, copy the data */ 580 ican3_set_page(mod, desc.pointer); 581 memcpy_fromio(msg, mod->dpm, sizeof(*msg)); 582 583 /* switch back to the descriptor, toggle the valid bit, write it back */ 584 ican3_set_page(mod, QUEUE_TOHOST); 585 desc.control ^= DESC_VALID; 586 memcpy_toio(desc_addr, &desc, sizeof(desc)); 587 588 /* update the rx number */ 589 mod->rx_num = (desc.control & DESC_WRAP) ? 0 : (mod->rx_num + 1); 590 return 0; 591} 592 593/* 594 * Message Send / Recv Helpers 595 */ 596 597static int ican3_send_msg(struct ican3_dev *mod, struct ican3_msg *msg) 598{ 599 unsigned long flags; 600 int ret; 601 602 spin_lock_irqsave(&mod->lock, flags); 603 604 if (mod->iftype == 0) 605 ret = ican3_old_send_msg(mod, msg); 606 else 607 ret = ican3_new_send_msg(mod, msg); 608 609 spin_unlock_irqrestore(&mod->lock, flags); 610 return ret; 611} 612 613static int ican3_recv_msg(struct ican3_dev *mod, struct ican3_msg *msg) 614{ 615 unsigned long flags; 616 int ret; 617 618 spin_lock_irqsave(&mod->lock, flags); 619 620 if (mod->iftype == 0) 621 ret = ican3_old_recv_msg(mod, msg); 622 else 623 ret = ican3_new_recv_msg(mod, msg); 624 625 spin_unlock_irqrestore(&mod->lock, flags); 626 return ret; 627} 628 629/* 630 * Quick Pre-constructed Messages 631 */ 632 633static int ican3_msg_connect(struct ican3_dev *mod) 634{ 635 struct ican3_msg msg; 636 637 memset(&msg, 0, sizeof(msg)); 638 msg.spec = MSG_CONNECTI; 639 msg.len = cpu_to_le16(0); 640 641 return ican3_send_msg(mod, &msg); 642} 643 644static int ican3_msg_disconnect(struct ican3_dev *mod) 645{ 646 struct ican3_msg msg; 647 648 memset(&msg, 0, sizeof(msg)); 649 msg.spec = MSG_DISCONNECT; 650 msg.len = cpu_to_le16(0); 651 652 return ican3_send_msg(mod, &msg); 653} 654 655static int ican3_msg_newhostif(struct ican3_dev *mod) 656{ 657 struct ican3_msg msg; 658 int ret; 659 660 memset(&msg, 0, sizeof(msg)); 661 msg.spec = MSG_NEWHOSTIF; 662 msg.len = cpu_to_le16(0); 663 664 /* If we're not using the old interface, switching seems bogus */ 665 WARN_ON(mod->iftype != 0); 666 667 ret = ican3_send_msg(mod, &msg); 668 if (ret) 669 return ret; 670 671 /* mark the module as using the new host interface */ 672 mod->iftype = 1; 673 return 0; 674} 675 676static int ican3_msg_fasthostif(struct ican3_dev *mod) 677{ 678 struct ican3_msg msg; 679 unsigned int addr; 680 681 memset(&msg, 0, sizeof(msg)); 682 msg.spec = MSG_INITFDPMQUEUE; 683 msg.len = cpu_to_le16(8); 684 685 /* write the tohost queue start address */ 686 addr = DPM_PAGE_ADDR(mod->fastrx_start); 687 msg.data[0] = addr & 0xff; 688 msg.data[1] = (addr >> 8) & 0xff; 689 msg.data[2] = (addr >> 16) & 0xff; 690 msg.data[3] = (addr >> 24) & 0xff; 691 692 /* write the fromhost queue start address */ 693 addr = DPM_PAGE_ADDR(mod->fasttx_start); 694 msg.data[4] = addr & 0xff; 695 msg.data[5] = (addr >> 8) & 0xff; 696 msg.data[6] = (addr >> 16) & 0xff; 697 msg.data[7] = (addr >> 24) & 0xff; 698 699 /* If we're not using the new interface yet, we cannot do this */ 700 WARN_ON(mod->iftype != 1); 701 702 return ican3_send_msg(mod, &msg); 703} 704 705/* 706 * Setup the CAN filter to either accept or reject all 707 * messages from the CAN bus. 708 */ 709static int ican3_set_id_filter(struct ican3_dev *mod, bool accept) 710{ 711 struct ican3_msg msg; 712 int ret; 713 714 /* Standard Frame Format */ 715 memset(&msg, 0, sizeof(msg)); 716 msg.spec = MSG_SETAFILMASK; 717 msg.len = cpu_to_le16(5); 718 msg.data[0] = 0x00; /* IDLo LSB */ 719 msg.data[1] = 0x00; /* IDLo MSB */ 720 msg.data[2] = 0xff; /* IDHi LSB */ 721 msg.data[3] = 0x07; /* IDHi MSB */ 722 723 /* accept all frames for fast host if, or reject all frames */ 724 msg.data[4] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; 725 726 ret = ican3_send_msg(mod, &msg); 727 if (ret) 728 return ret; 729 730 /* Extended Frame Format */ 731 memset(&msg, 0, sizeof(msg)); 732 msg.spec = MSG_SETAFILMASK; 733 msg.len = cpu_to_le16(13); 734 msg.data[0] = 0; /* MUX = 0 */ 735 msg.data[1] = 0x00; /* IDLo LSB */ 736 msg.data[2] = 0x00; 737 msg.data[3] = 0x00; 738 msg.data[4] = 0x20; /* IDLo MSB */ 739 msg.data[5] = 0xff; /* IDHi LSB */ 740 msg.data[6] = 0xff; 741 msg.data[7] = 0xff; 742 msg.data[8] = 0x3f; /* IDHi MSB */ 743 744 /* accept all frames for fast host if, or reject all frames */ 745 msg.data[9] = accept ? SETAFILMASK_FASTIF : SETAFILMASK_REJECT; 746 747 return ican3_send_msg(mod, &msg); 748} 749 750/* 751 * Bring the CAN bus online or offline 752 */ 753static int ican3_set_bus_state(struct ican3_dev *mod, bool on) 754{ 755 struct ican3_msg msg; 756 757 memset(&msg, 0, sizeof(msg)); 758 msg.spec = on ? MSG_CONREQ : MSG_COFFREQ; 759 msg.len = cpu_to_le16(0); 760 761 return ican3_send_msg(mod, &msg); 762} 763 764static int ican3_set_termination(struct ican3_dev *mod, bool on) 765{ 766 struct ican3_msg msg; 767 768 memset(&msg, 0, sizeof(msg)); 769 msg.spec = MSG_HWCONF; 770 msg.len = cpu_to_le16(2); 771 msg.data[0] = 0x00; 772 msg.data[1] = on ? HWCONF_TERMINATE_ON : HWCONF_TERMINATE_OFF; 773 774 return ican3_send_msg(mod, &msg); 775} 776 777static int ican3_send_inquiry(struct ican3_dev *mod, u8 subspec) 778{ 779 struct ican3_msg msg; 780 781 memset(&msg, 0, sizeof(msg)); 782 msg.spec = MSG_INQUIRY; 783 msg.len = cpu_to_le16(2); 784 msg.data[0] = subspec; 785 msg.data[1] = 0x00; 786 787 return ican3_send_msg(mod, &msg); 788} 789 790static int ican3_set_buserror(struct ican3_dev *mod, u8 quota) 791{ 792 struct ican3_msg msg; 793 794 memset(&msg, 0, sizeof(msg)); 795 msg.spec = MSG_CCONFREQ; 796 msg.len = cpu_to_le16(2); 797 msg.data[0] = 0x00; 798 msg.data[1] = quota; 799 800 return ican3_send_msg(mod, &msg); 801} 802 803/* 804 * ICAN3 to Linux CAN Frame Conversion 805 */ 806 807static void ican3_to_can_frame(struct ican3_dev *mod, 808 struct ican3_fast_desc *desc, 809 struct can_frame *cf) 810{ 811 if ((desc->command & ICAN3_CAN_TYPE_MASK) == ICAN3_CAN_TYPE_SFF) { 812 if (desc->data[1] & ICAN3_SFF_RTR) 813 cf->can_id |= CAN_RTR_FLAG; 814 815 cf->can_id |= desc->data[0] << 3; 816 cf->can_id |= (desc->data[1] & 0xe0) >> 5; 817 cf->can_dlc = get_can_dlc(desc->data[1] & ICAN3_CAN_DLC_MASK); 818 memcpy(cf->data, &desc->data[2], cf->can_dlc); 819 } else { 820 cf->can_dlc = get_can_dlc(desc->data[0] & ICAN3_CAN_DLC_MASK); 821 if (desc->data[0] & ICAN3_EFF_RTR) 822 cf->can_id |= CAN_RTR_FLAG; 823 824 if (desc->data[0] & ICAN3_EFF) { 825 cf->can_id |= CAN_EFF_FLAG; 826 cf->can_id |= desc->data[2] << 21; /* 28-21 */ 827 cf->can_id |= desc->data[3] << 13; /* 20-13 */ 828 cf->can_id |= desc->data[4] << 5; /* 12-5 */ 829 cf->can_id |= (desc->data[5] & 0xf8) >> 3; 830 } else { 831 cf->can_id |= desc->data[2] << 3; /* 10-3 */ 832 cf->can_id |= desc->data[3] >> 5; /* 2-0 */ 833 } 834 835 memcpy(cf->data, &desc->data[6], cf->can_dlc); 836 } 837} 838 839static void can_frame_to_ican3(struct ican3_dev *mod, 840 struct can_frame *cf, 841 struct ican3_fast_desc *desc) 842{ 843 /* clear out any stale data in the descriptor */ 844 memset(desc->data, 0, sizeof(desc->data)); 845 846 /* we always use the extended format, with the ECHO flag set */ 847 desc->command = ICAN3_CAN_TYPE_EFF; 848 desc->data[0] |= cf->can_dlc; 849 desc->data[1] |= ICAN3_ECHO; 850 851 /* support single transmission (no retries) mode */ 852 if (mod->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT) 853 desc->data[1] |= ICAN3_SNGL; 854 855 if (cf->can_id & CAN_RTR_FLAG) 856 desc->data[0] |= ICAN3_EFF_RTR; 857 858 /* pack the id into the correct places */ 859 if (cf->can_id & CAN_EFF_FLAG) { 860 desc->data[0] |= ICAN3_EFF; 861 desc->data[2] = (cf->can_id & 0x1fe00000) >> 21; /* 28-21 */ 862 desc->data[3] = (cf->can_id & 0x001fe000) >> 13; /* 20-13 */ 863 desc->data[4] = (cf->can_id & 0x00001fe0) >> 5; /* 12-5 */ 864 desc->data[5] = (cf->can_id & 0x0000001f) << 3; /* 4-0 */ 865 } else { 866 desc->data[2] = (cf->can_id & 0x7F8) >> 3; /* bits 10-3 */ 867 desc->data[3] = (cf->can_id & 0x007) << 5; /* bits 2-0 */ 868 } 869 870 /* copy the data bits into the descriptor */ 871 memcpy(&desc->data[6], cf->data, cf->can_dlc); 872} 873 874/* 875 * Interrupt Handling 876 */ 877 878/* 879 * Handle an ID + Version message response from the firmware. We never generate 880 * this message in production code, but it is very useful when debugging to be 881 * able to display this message. 882 */ 883static void ican3_handle_idvers(struct ican3_dev *mod, struct ican3_msg *msg) 884{ 885 dev_dbg(mod->dev, "IDVERS response: %s\n", msg->data); 886} 887 888static void ican3_handle_msglost(struct ican3_dev *mod, struct ican3_msg *msg) 889{ 890 struct net_device *dev = mod->ndev; 891 struct net_device_stats *stats = &dev->stats; 892 struct can_frame *cf; 893 struct sk_buff *skb; 894 895 /* 896 * Report that communication messages with the microcontroller firmware 897 * are being lost. These are never CAN frames, so we do not generate an 898 * error frame for userspace 899 */ 900 if (msg->spec == MSG_MSGLOST) { 901 dev_err(mod->dev, "lost %d control messages\n", msg->data[0]); 902 return; 903 } 904 905 /* 906 * Oops, this indicates that we have lost messages in the fast queue, 907 * which are exclusively CAN messages. Our driver isn't reading CAN 908 * frames fast enough. 909 * 910 * We'll pretend that the SJA1000 told us that it ran out of buffer 911 * space, because there is not a better message for this. 912 */ 913 skb = alloc_can_err_skb(dev, &cf); 914 if (skb) { 915 cf->can_id |= CAN_ERR_CRTL; 916 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 917 stats->rx_over_errors++; 918 stats->rx_errors++; 919 netif_rx(skb); 920 } 921} 922 923/* 924 * Handle CAN Event Indication Messages from the firmware 925 * 926 * The ICAN3 firmware provides the values of some SJA1000 registers when it 927 * generates this message. The code below is largely copied from the 928 * drivers/net/can/sja1000/sja1000.c file, and adapted as necessary 929 */ 930static int ican3_handle_cevtind(struct ican3_dev *mod, struct ican3_msg *msg) 931{ 932 struct net_device *dev = mod->ndev; 933 struct net_device_stats *stats = &dev->stats; 934 enum can_state state = mod->can.state; 935 u8 isrc, ecc, status, rxerr, txerr; 936 struct can_frame *cf; 937 struct sk_buff *skb; 938 939 /* we can only handle the SJA1000 part */ 940 if (msg->data[1] != CEVTIND_CHIP_SJA1000) { 941 dev_err(mod->dev, "unable to handle errors on non-SJA1000\n"); 942 return -ENODEV; 943 } 944 945 /* check the message length for sanity */ 946 if (le16_to_cpu(msg->len) < 6) { 947 dev_err(mod->dev, "error message too short\n"); 948 return -EINVAL; 949 } 950 951 isrc = msg->data[0]; 952 ecc = msg->data[2]; 953 status = msg->data[3]; 954 rxerr = msg->data[4]; 955 txerr = msg->data[5]; 956 957 /* 958 * This hardware lacks any support other than bus error messages to 959 * determine if packet transmission has failed. 960 * 961 * When TX errors happen, one echo skb needs to be dropped from the 962 * front of the queue. 963 * 964 * A small bit of code is duplicated here and below, to avoid error 965 * skb allocation when it will just be freed immediately. 966 */ 967 if (isrc == CEVTIND_BEI) { 968 int ret; 969 dev_dbg(mod->dev, "bus error interrupt\n"); 970 971 /* TX error */ 972 if (!(ecc & ECC_DIR)) { 973 kfree_skb(skb_dequeue(&mod->echoq)); 974 stats->tx_errors++; 975 } else { 976 stats->rx_errors++; 977 } 978 979 /* 980 * The controller automatically disables bus-error interrupts 981 * and therefore we must re-enable them. 982 */ 983 ret = ican3_set_buserror(mod, 1); 984 if (ret) { 985 dev_err(mod->dev, "unable to re-enable bus-error\n"); 986 return ret; 987 } 988 989 /* bus error reporting is off, return immediately */ 990 if (!(mod->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) 991 return 0; 992 } 993 994 skb = alloc_can_err_skb(dev, &cf); 995 if (skb == NULL) 996 return -ENOMEM; 997 998 /* data overrun interrupt */ 999 if (isrc == CEVTIND_DOI || isrc == CEVTIND_LOST) { 1000 dev_dbg(mod->dev, "data overrun interrupt\n"); 1001 cf->can_id |= CAN_ERR_CRTL; 1002 cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW; 1003 stats->rx_over_errors++; 1004 stats->rx_errors++; 1005 } 1006 1007 /* error warning + passive interrupt */ 1008 if (isrc == CEVTIND_EI) { 1009 dev_dbg(mod->dev, "error warning + passive interrupt\n"); 1010 if (status & SR_BS) { 1011 state = CAN_STATE_BUS_OFF; 1012 cf->can_id |= CAN_ERR_BUSOFF; 1013 can_bus_off(dev); 1014 } else if (status & SR_ES) { 1015 if (rxerr >= 128 || txerr >= 128) 1016 state = CAN_STATE_ERROR_PASSIVE; 1017 else 1018 state = CAN_STATE_ERROR_WARNING; 1019 } else { 1020 state = CAN_STATE_ERROR_ACTIVE; 1021 } 1022 } 1023 1024 /* bus error interrupt */ 1025 if (isrc == CEVTIND_BEI) { 1026 mod->can.can_stats.bus_error++; 1027 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR; 1028 1029 switch (ecc & ECC_MASK) { 1030 case ECC_BIT: 1031 cf->data[2] |= CAN_ERR_PROT_BIT; 1032 break; 1033 case ECC_FORM: 1034 cf->data[2] |= CAN_ERR_PROT_FORM; 1035 break; 1036 case ECC_STUFF: 1037 cf->data[2] |= CAN_ERR_PROT_STUFF; 1038 break; 1039 default: 1040 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 1041 cf->data[3] = ecc & ECC_SEG; 1042 break; 1043 } 1044 1045 if (!(ecc & ECC_DIR)) 1046 cf->data[2] |= CAN_ERR_PROT_TX; 1047 1048 cf->data[6] = txerr; 1049 cf->data[7] = rxerr; 1050 } 1051 1052 if (state != mod->can.state && (state == CAN_STATE_ERROR_WARNING || 1053 state == CAN_STATE_ERROR_PASSIVE)) { 1054 cf->can_id |= CAN_ERR_CRTL; 1055 if (state == CAN_STATE_ERROR_WARNING) { 1056 mod->can.can_stats.error_warning++; 1057 cf->data[1] = (txerr > rxerr) ? 1058 CAN_ERR_CRTL_TX_WARNING : 1059 CAN_ERR_CRTL_RX_WARNING; 1060 } else { 1061 mod->can.can_stats.error_passive++; 1062 cf->data[1] = (txerr > rxerr) ? 1063 CAN_ERR_CRTL_TX_PASSIVE : 1064 CAN_ERR_CRTL_RX_PASSIVE; 1065 } 1066 1067 cf->data[6] = txerr; 1068 cf->data[7] = rxerr; 1069 } 1070 1071 mod->can.state = state; 1072 netif_rx(skb); 1073 return 0; 1074} 1075 1076static void ican3_handle_inquiry(struct ican3_dev *mod, struct ican3_msg *msg) 1077{ 1078 switch (msg->data[0]) { 1079 case INQUIRY_STATUS: 1080 case INQUIRY_EXTENDED: 1081 mod->bec.rxerr = msg->data[5]; 1082 mod->bec.txerr = msg->data[6]; 1083 complete(&mod->buserror_comp); 1084 break; 1085 case INQUIRY_TERMINATION: 1086 mod->termination_enabled = msg->data[6] & HWCONF_TERMINATE_ON; 1087 complete(&mod->termination_comp); 1088 break; 1089 default: 1090 dev_err(mod->dev, "received an unknown inquiry response\n"); 1091 break; 1092 } 1093} 1094 1095static void ican3_handle_unknown_message(struct ican3_dev *mod, 1096 struct ican3_msg *msg) 1097{ 1098 dev_warn(mod->dev, "received unknown message: spec 0x%.2x length %d\n", 1099 msg->spec, le16_to_cpu(msg->len)); 1100} 1101 1102/* 1103 * Handle a control message from the firmware 1104 */ 1105static void ican3_handle_message(struct ican3_dev *mod, struct ican3_msg *msg) 1106{ 1107 dev_dbg(mod->dev, "%s: modno %d spec 0x%.2x len %d bytes\n", __func__, 1108 mod->num, msg->spec, le16_to_cpu(msg->len)); 1109 1110 switch (msg->spec) { 1111 case MSG_IDVERS: 1112 ican3_handle_idvers(mod, msg); 1113 break; 1114 case MSG_MSGLOST: 1115 case MSG_FMSGLOST: 1116 ican3_handle_msglost(mod, msg); 1117 break; 1118 case MSG_CEVTIND: 1119 ican3_handle_cevtind(mod, msg); 1120 break; 1121 case MSG_INQUIRY: 1122 ican3_handle_inquiry(mod, msg); 1123 break; 1124 default: 1125 ican3_handle_unknown_message(mod, msg); 1126 break; 1127 } 1128} 1129 1130/* 1131 * The ican3 needs to store all echo skbs, and therefore cannot 1132 * use the generic infrastructure for this. 1133 */ 1134static void ican3_put_echo_skb(struct ican3_dev *mod, struct sk_buff *skb) 1135{ 1136 struct sock *srcsk = skb->sk; 1137 1138 if (atomic_read(&skb->users) != 1) { 1139 struct sk_buff *old_skb = skb; 1140 1141 skb = skb_clone(old_skb, GFP_ATOMIC); 1142 kfree_skb(old_skb); 1143 if (!skb) 1144 return; 1145 } else { 1146 skb_orphan(skb); 1147 } 1148 1149 skb->sk = srcsk; 1150 1151 /* save this skb for tx interrupt echo handling */ 1152 skb_queue_tail(&mod->echoq, skb); 1153} 1154 1155static unsigned int ican3_get_echo_skb(struct ican3_dev *mod) 1156{ 1157 struct sk_buff *skb = skb_dequeue(&mod->echoq); 1158 struct can_frame *cf; 1159 u8 dlc; 1160 1161 /* this should never trigger unless there is a driver bug */ 1162 if (!skb) { 1163 netdev_err(mod->ndev, "BUG: echo skb not occupied\n"); 1164 return 0; 1165 } 1166 1167 cf = (struct can_frame *)skb->data; 1168 dlc = cf->can_dlc; 1169 1170 /* check flag whether this packet has to be looped back */ 1171 if (skb->pkt_type != PACKET_LOOPBACK) { 1172 kfree_skb(skb); 1173 return dlc; 1174 } 1175 1176 skb->protocol = htons(ETH_P_CAN); 1177 skb->pkt_type = PACKET_BROADCAST; 1178 skb->ip_summed = CHECKSUM_UNNECESSARY; 1179 skb->dev = mod->ndev; 1180 netif_receive_skb(skb); 1181 return dlc; 1182} 1183 1184/* 1185 * Compare an skb with an existing echo skb 1186 * 1187 * This function will be used on devices which have a hardware loopback. 1188 * On these devices, this function can be used to compare a received skb 1189 * with the saved echo skbs so that the hardware echo skb can be dropped. 1190 * 1191 * Returns true if the skb's are identical, false otherwise. 1192 */ 1193static bool ican3_echo_skb_matches(struct ican3_dev *mod, struct sk_buff *skb) 1194{ 1195 struct can_frame *cf = (struct can_frame *)skb->data; 1196 struct sk_buff *echo_skb = skb_peek(&mod->echoq); 1197 struct can_frame *echo_cf; 1198 1199 if (!echo_skb) 1200 return false; 1201 1202 echo_cf = (struct can_frame *)echo_skb->data; 1203 if (cf->can_id != echo_cf->can_id) 1204 return false; 1205 1206 if (cf->can_dlc != echo_cf->can_dlc) 1207 return false; 1208 1209 return memcmp(cf->data, echo_cf->data, cf->can_dlc) == 0; 1210} 1211 1212/* 1213 * Check that there is room in the TX ring to transmit another skb 1214 * 1215 * LOCKING: must hold mod->lock 1216 */ 1217static bool ican3_txok(struct ican3_dev *mod) 1218{ 1219 struct ican3_fast_desc __iomem *desc; 1220 u8 control; 1221 1222 /* check that we have echo queue space */ 1223 if (skb_queue_len(&mod->echoq) >= ICAN3_TX_BUFFERS) 1224 return false; 1225 1226 /* copy the control bits of the descriptor */ 1227 ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); 1228 desc = mod->dpm + ((mod->fasttx_num % 16) * sizeof(*desc)); 1229 control = ioread8(&desc->control); 1230 1231 /* if the control bits are not valid, then we have no more space */ 1232 if (!(control & DESC_VALID)) 1233 return false; 1234 1235 return true; 1236} 1237 1238/* 1239 * Receive one CAN frame from the hardware 1240 * 1241 * CONTEXT: must be called from user context 1242 */ 1243static int ican3_recv_skb(struct ican3_dev *mod) 1244{ 1245 struct net_device *ndev = mod->ndev; 1246 struct net_device_stats *stats = &ndev->stats; 1247 struct ican3_fast_desc desc; 1248 void __iomem *desc_addr; 1249 struct can_frame *cf; 1250 struct sk_buff *skb; 1251 unsigned long flags; 1252 1253 spin_lock_irqsave(&mod->lock, flags); 1254 1255 /* copy the whole descriptor */ 1256 ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); 1257 desc_addr = mod->dpm + ((mod->fastrx_num % 16) * sizeof(desc)); 1258 memcpy_fromio(&desc, desc_addr, sizeof(desc)); 1259 1260 spin_unlock_irqrestore(&mod->lock, flags); 1261 1262 /* check that we actually have a CAN frame */ 1263 if (!(desc.control & DESC_VALID)) 1264 return -ENOBUFS; 1265 1266 /* allocate an skb */ 1267 skb = alloc_can_skb(ndev, &cf); 1268 if (unlikely(skb == NULL)) { 1269 stats->rx_dropped++; 1270 goto err_noalloc; 1271 } 1272 1273 /* convert the ICAN3 frame into Linux CAN format */ 1274 ican3_to_can_frame(mod, &desc, cf); 1275 1276 /* 1277 * If this is an ECHO frame received from the hardware loopback 1278 * feature, use the skb saved in the ECHO stack instead. This allows 1279 * the Linux CAN core to support CAN_RAW_RECV_OWN_MSGS correctly. 1280 * 1281 * Since this is a confirmation of a successfully transmitted packet 1282 * sent from this host, update the transmit statistics. 1283 * 1284 * Also, the netdevice queue needs to be allowed to send packets again. 1285 */ 1286 if (ican3_echo_skb_matches(mod, skb)) { 1287 stats->tx_packets++; 1288 stats->tx_bytes += ican3_get_echo_skb(mod); 1289 kfree_skb(skb); 1290 goto err_noalloc; 1291 } 1292 1293 /* update statistics, receive the skb */ 1294 stats->rx_packets++; 1295 stats->rx_bytes += cf->can_dlc; 1296 netif_receive_skb(skb); 1297 1298err_noalloc: 1299 /* toggle the valid bit and return the descriptor to the ring */ 1300 desc.control ^= DESC_VALID; 1301 1302 spin_lock_irqsave(&mod->lock, flags); 1303 1304 ican3_set_page(mod, mod->fastrx_start + (mod->fastrx_num / 16)); 1305 memcpy_toio(desc_addr, &desc, 1); 1306 1307 /* update the next buffer pointer */ 1308 mod->fastrx_num = (desc.control & DESC_WRAP) ? 0 1309 : (mod->fastrx_num + 1); 1310 1311 /* there are still more buffers to process */ 1312 spin_unlock_irqrestore(&mod->lock, flags); 1313 return 0; 1314} 1315 1316static int ican3_napi(struct napi_struct *napi, int budget) 1317{ 1318 struct ican3_dev *mod = container_of(napi, struct ican3_dev, napi); 1319 unsigned long flags; 1320 int received = 0; 1321 int ret; 1322 1323 /* process all communication messages */ 1324 while (true) { 1325 struct ican3_msg uninitialized_var(msg); 1326 ret = ican3_recv_msg(mod, &msg); 1327 if (ret) 1328 break; 1329 1330 ican3_handle_message(mod, &msg); 1331 } 1332 1333 /* process all CAN frames from the fast interface */ 1334 while (received < budget) { 1335 ret = ican3_recv_skb(mod); 1336 if (ret) 1337 break; 1338 1339 received++; 1340 } 1341 1342 /* We have processed all packets that the adapter had, but it 1343 * was less than our budget, stop polling */ 1344 if (received < budget) 1345 napi_complete(napi); 1346 1347 spin_lock_irqsave(&mod->lock, flags); 1348 1349 /* Wake up the transmit queue if necessary */ 1350 if (netif_queue_stopped(mod->ndev) && ican3_txok(mod)) 1351 netif_wake_queue(mod->ndev); 1352 1353 spin_unlock_irqrestore(&mod->lock, flags); 1354 1355 /* re-enable interrupt generation */ 1356 iowrite8(1 << mod->num, &mod->ctrl->int_enable); 1357 return received; 1358} 1359 1360static irqreturn_t ican3_irq(int irq, void *dev_id) 1361{ 1362 struct ican3_dev *mod = dev_id; 1363 u8 stat; 1364 1365 /* 1366 * The interrupt status register on this device reports interrupts 1367 * as zeroes instead of using ones like most other devices 1368 */ 1369 stat = ioread8(&mod->ctrl->int_disable) & (1 << mod->num); 1370 if (stat == (1 << mod->num)) 1371 return IRQ_NONE; 1372 1373 /* clear the MODULbus interrupt from the microcontroller */ 1374 ioread8(&mod->dpmctrl->interrupt); 1375 1376 /* disable interrupt generation, schedule the NAPI poller */ 1377 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1378 napi_schedule(&mod->napi); 1379 return IRQ_HANDLED; 1380} 1381 1382/* 1383 * Firmware reset, startup, and shutdown 1384 */ 1385 1386/* 1387 * Reset an ICAN module to its power-on state 1388 * 1389 * CONTEXT: no network device registered 1390 */ 1391static int ican3_reset_module(struct ican3_dev *mod) 1392{ 1393 unsigned long start; 1394 u8 runold, runnew; 1395 1396 /* disable interrupts so no more work is scheduled */ 1397 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1398 1399 /* the first unallocated page in the DPM is #9 */ 1400 mod->free_page = DPM_FREE_START; 1401 1402 ican3_set_page(mod, QUEUE_OLD_CONTROL); 1403 runold = ioread8(mod->dpm + TARGET_RUNNING); 1404 1405 /* reset the module */ 1406 iowrite8(0x00, &mod->dpmctrl->hwreset); 1407 1408 /* wait until the module has finished resetting and is running */ 1409 start = jiffies; 1410 do { 1411 ican3_set_page(mod, QUEUE_OLD_CONTROL); 1412 runnew = ioread8(mod->dpm + TARGET_RUNNING); 1413 if (runnew == (runold ^ 0xff)) 1414 return 0; 1415 1416 msleep(10); 1417 } while (time_before(jiffies, start + HZ / 4)); 1418 1419 dev_err(mod->dev, "failed to reset CAN module\n"); 1420 return -ETIMEDOUT; 1421} 1422 1423static void ican3_shutdown_module(struct ican3_dev *mod) 1424{ 1425 ican3_msg_disconnect(mod); 1426 ican3_reset_module(mod); 1427} 1428 1429/* 1430 * Startup an ICAN module, bringing it into fast mode 1431 */ 1432static int ican3_startup_module(struct ican3_dev *mod) 1433{ 1434 int ret; 1435 1436 ret = ican3_reset_module(mod); 1437 if (ret) { 1438 dev_err(mod->dev, "unable to reset module\n"); 1439 return ret; 1440 } 1441 1442 /* re-enable interrupts so we can send messages */ 1443 iowrite8(1 << mod->num, &mod->ctrl->int_enable); 1444 1445 ret = ican3_msg_connect(mod); 1446 if (ret) { 1447 dev_err(mod->dev, "unable to connect to module\n"); 1448 return ret; 1449 } 1450 1451 ican3_init_new_host_interface(mod); 1452 ret = ican3_msg_newhostif(mod); 1453 if (ret) { 1454 dev_err(mod->dev, "unable to switch to new-style interface\n"); 1455 return ret; 1456 } 1457 1458 /* default to "termination on" */ 1459 ret = ican3_set_termination(mod, true); 1460 if (ret) { 1461 dev_err(mod->dev, "unable to enable termination\n"); 1462 return ret; 1463 } 1464 1465 /* default to "bus errors enabled" */ 1466 ret = ican3_set_buserror(mod, 1); 1467 if (ret) { 1468 dev_err(mod->dev, "unable to set bus-error\n"); 1469 return ret; 1470 } 1471 1472 ican3_init_fast_host_interface(mod); 1473 ret = ican3_msg_fasthostif(mod); 1474 if (ret) { 1475 dev_err(mod->dev, "unable to switch to fast host interface\n"); 1476 return ret; 1477 } 1478 1479 ret = ican3_set_id_filter(mod, true); 1480 if (ret) { 1481 dev_err(mod->dev, "unable to set acceptance filter\n"); 1482 return ret; 1483 } 1484 1485 return 0; 1486} 1487 1488/* 1489 * CAN Network Device 1490 */ 1491 1492static int ican3_open(struct net_device *ndev) 1493{ 1494 struct ican3_dev *mod = netdev_priv(ndev); 1495 int ret; 1496 1497 /* open the CAN layer */ 1498 ret = open_candev(ndev); 1499 if (ret) { 1500 dev_err(mod->dev, "unable to start CAN layer\n"); 1501 return ret; 1502 } 1503 1504 /* bring the bus online */ 1505 ret = ican3_set_bus_state(mod, true); 1506 if (ret) { 1507 dev_err(mod->dev, "unable to set bus-on\n"); 1508 close_candev(ndev); 1509 return ret; 1510 } 1511 1512 /* start up the network device */ 1513 mod->can.state = CAN_STATE_ERROR_ACTIVE; 1514 netif_start_queue(ndev); 1515 1516 return 0; 1517} 1518 1519static int ican3_stop(struct net_device *ndev) 1520{ 1521 struct ican3_dev *mod = netdev_priv(ndev); 1522 int ret; 1523 1524 /* stop the network device xmit routine */ 1525 netif_stop_queue(ndev); 1526 mod->can.state = CAN_STATE_STOPPED; 1527 1528 /* bring the bus offline, stop receiving packets */ 1529 ret = ican3_set_bus_state(mod, false); 1530 if (ret) { 1531 dev_err(mod->dev, "unable to set bus-off\n"); 1532 return ret; 1533 } 1534 1535 /* drop all outstanding echo skbs */ 1536 skb_queue_purge(&mod->echoq); 1537 1538 /* close the CAN layer */ 1539 close_candev(ndev); 1540 return 0; 1541} 1542 1543static int ican3_xmit(struct sk_buff *skb, struct net_device *ndev) 1544{ 1545 struct ican3_dev *mod = netdev_priv(ndev); 1546 struct can_frame *cf = (struct can_frame *)skb->data; 1547 struct ican3_fast_desc desc; 1548 void __iomem *desc_addr; 1549 unsigned long flags; 1550 1551 if (can_dropped_invalid_skb(ndev, skb)) 1552 return NETDEV_TX_OK; 1553 1554 spin_lock_irqsave(&mod->lock, flags); 1555 1556 /* check that we can actually transmit */ 1557 if (!ican3_txok(mod)) { 1558 dev_err(mod->dev, "BUG: no free descriptors\n"); 1559 spin_unlock_irqrestore(&mod->lock, flags); 1560 return NETDEV_TX_BUSY; 1561 } 1562 1563 /* copy the control bits of the descriptor */ 1564 ican3_set_page(mod, mod->fasttx_start + (mod->fasttx_num / 16)); 1565 desc_addr = mod->dpm + ((mod->fasttx_num % 16) * sizeof(desc)); 1566 memset(&desc, 0, sizeof(desc)); 1567 memcpy_fromio(&desc, desc_addr, 1); 1568 1569 /* convert the Linux CAN frame into ICAN3 format */ 1570 can_frame_to_ican3(mod, cf, &desc); 1571 1572 /* 1573 * This hardware doesn't have TX-done notifications, so we'll try and 1574 * emulate it the best we can using ECHO skbs. Add the skb to the ECHO 1575 * stack. Upon packet reception, check if the ECHO skb and received 1576 * skb match, and use that to wake the queue. 1577 */ 1578 ican3_put_echo_skb(mod, skb); 1579 1580 /* 1581 * the programming manual says that you must set the IVALID bit, then 1582 * interrupt, then set the valid bit. Quite weird, but it seems to be 1583 * required for this to work 1584 */ 1585 desc.control |= DESC_IVALID; 1586 memcpy_toio(desc_addr, &desc, sizeof(desc)); 1587 1588 /* generate a MODULbus interrupt to the microcontroller */ 1589 iowrite8(0x01, &mod->dpmctrl->interrupt); 1590 1591 desc.control ^= DESC_VALID; 1592 memcpy_toio(desc_addr, &desc, sizeof(desc)); 1593 1594 /* update the next buffer pointer */ 1595 mod->fasttx_num = (desc.control & DESC_WRAP) ? 0 1596 : (mod->fasttx_num + 1); 1597 1598 /* if there is no free descriptor space, stop the transmit queue */ 1599 if (!ican3_txok(mod)) 1600 netif_stop_queue(ndev); 1601 1602 spin_unlock_irqrestore(&mod->lock, flags); 1603 return NETDEV_TX_OK; 1604} 1605 1606static const struct net_device_ops ican3_netdev_ops = { 1607 .ndo_open = ican3_open, 1608 .ndo_stop = ican3_stop, 1609 .ndo_start_xmit = ican3_xmit, 1610}; 1611 1612/* 1613 * Low-level CAN Device 1614 */ 1615 1616/* This structure was stolen from drivers/net/can/sja1000/sja1000.c */ 1617static const struct can_bittiming_const ican3_bittiming_const = { 1618 .name = DRV_NAME, 1619 .tseg1_min = 1, 1620 .tseg1_max = 16, 1621 .tseg2_min = 1, 1622 .tseg2_max = 8, 1623 .sjw_max = 4, 1624 .brp_min = 1, 1625 .brp_max = 64, 1626 .brp_inc = 1, 1627}; 1628 1629/* 1630 * This routine was stolen from drivers/net/can/sja1000/sja1000.c 1631 * 1632 * The bittiming register command for the ICAN3 just sets the bit timing 1633 * registers on the SJA1000 chip directly 1634 */ 1635static int ican3_set_bittiming(struct net_device *ndev) 1636{ 1637 struct ican3_dev *mod = netdev_priv(ndev); 1638 struct can_bittiming *bt = &mod->can.bittiming; 1639 struct ican3_msg msg; 1640 u8 btr0, btr1; 1641 1642 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 1643 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 1644 (((bt->phase_seg2 - 1) & 0x7) << 4); 1645 if (mod->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 1646 btr1 |= 0x80; 1647 1648 memset(&msg, 0, sizeof(msg)); 1649 msg.spec = MSG_CBTRREQ; 1650 msg.len = cpu_to_le16(4); 1651 msg.data[0] = 0x00; 1652 msg.data[1] = 0x00; 1653 msg.data[2] = btr0; 1654 msg.data[3] = btr1; 1655 1656 return ican3_send_msg(mod, &msg); 1657} 1658 1659static int ican3_set_mode(struct net_device *ndev, enum can_mode mode) 1660{ 1661 struct ican3_dev *mod = netdev_priv(ndev); 1662 int ret; 1663 1664 if (mode != CAN_MODE_START) 1665 return -ENOTSUPP; 1666 1667 /* bring the bus online */ 1668 ret = ican3_set_bus_state(mod, true); 1669 if (ret) { 1670 dev_err(mod->dev, "unable to set bus-on\n"); 1671 return ret; 1672 } 1673 1674 /* start up the network device */ 1675 mod->can.state = CAN_STATE_ERROR_ACTIVE; 1676 1677 if (netif_queue_stopped(ndev)) 1678 netif_wake_queue(ndev); 1679 1680 return 0; 1681} 1682 1683static int ican3_get_berr_counter(const struct net_device *ndev, 1684 struct can_berr_counter *bec) 1685{ 1686 struct ican3_dev *mod = netdev_priv(ndev); 1687 int ret; 1688 1689 ret = ican3_send_inquiry(mod, INQUIRY_STATUS); 1690 if (ret) 1691 return ret; 1692 1693 ret = wait_for_completion_timeout(&mod->buserror_comp, HZ); 1694 if (ret == 0) { 1695 dev_info(mod->dev, "%s timed out\n", __func__); 1696 return -ETIMEDOUT; 1697 } 1698 1699 bec->rxerr = mod->bec.rxerr; 1700 bec->txerr = mod->bec.txerr; 1701 return 0; 1702} 1703 1704/* 1705 * Sysfs Attributes 1706 */ 1707 1708static ssize_t ican3_sysfs_show_term(struct device *dev, 1709 struct device_attribute *attr, 1710 char *buf) 1711{ 1712 struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); 1713 int ret; 1714 1715 ret = ican3_send_inquiry(mod, INQUIRY_TERMINATION); 1716 if (ret) 1717 return ret; 1718 1719 ret = wait_for_completion_timeout(&mod->termination_comp, HZ); 1720 if (ret == 0) { 1721 dev_info(mod->dev, "%s timed out\n", __func__); 1722 return -ETIMEDOUT; 1723 } 1724 1725 return snprintf(buf, PAGE_SIZE, "%u\n", mod->termination_enabled); 1726} 1727 1728static ssize_t ican3_sysfs_set_term(struct device *dev, 1729 struct device_attribute *attr, 1730 const char *buf, size_t count) 1731{ 1732 struct ican3_dev *mod = netdev_priv(to_net_dev(dev)); 1733 unsigned long enable; 1734 int ret; 1735 1736 if (kstrtoul(buf, 0, &enable)) 1737 return -EINVAL; 1738 1739 ret = ican3_set_termination(mod, enable); 1740 if (ret) 1741 return ret; 1742 1743 return count; 1744} 1745 1746static DEVICE_ATTR(termination, S_IWUSR | S_IRUGO, ican3_sysfs_show_term, 1747 ican3_sysfs_set_term); 1748 1749static struct attribute *ican3_sysfs_attrs[] = { 1750 &dev_attr_termination.attr, 1751 NULL, 1752}; 1753 1754static struct attribute_group ican3_sysfs_attr_group = { 1755 .attrs = ican3_sysfs_attrs, 1756}; 1757 1758/* 1759 * PCI Subsystem 1760 */ 1761 1762static int ican3_probe(struct platform_device *pdev) 1763{ 1764 struct janz_platform_data *pdata; 1765 struct net_device *ndev; 1766 struct ican3_dev *mod; 1767 struct resource *res; 1768 struct device *dev; 1769 int ret; 1770 1771 pdata = dev_get_platdata(&pdev->dev); 1772 if (!pdata) 1773 return -ENXIO; 1774 1775 dev_dbg(&pdev->dev, "probe: module number %d\n", pdata->modno); 1776 1777 /* save the struct device for printing */ 1778 dev = &pdev->dev; 1779 1780 /* allocate the CAN device and private data */ 1781 ndev = alloc_candev(sizeof(*mod), 0); 1782 if (!ndev) { 1783 dev_err(dev, "unable to allocate CANdev\n"); 1784 ret = -ENOMEM; 1785 goto out_return; 1786 } 1787 1788 platform_set_drvdata(pdev, ndev); 1789 mod = netdev_priv(ndev); 1790 mod->ndev = ndev; 1791 mod->dev = &pdev->dev; 1792 mod->num = pdata->modno; 1793 netif_napi_add(ndev, &mod->napi, ican3_napi, ICAN3_RX_BUFFERS); 1794 skb_queue_head_init(&mod->echoq); 1795 spin_lock_init(&mod->lock); 1796 init_completion(&mod->termination_comp); 1797 init_completion(&mod->buserror_comp); 1798 1799 /* setup device-specific sysfs attributes */ 1800 ndev->sysfs_groups[0] = &ican3_sysfs_attr_group; 1801 1802 /* the first unallocated page in the DPM is 9 */ 1803 mod->free_page = DPM_FREE_START; 1804 1805 ndev->netdev_ops = &ican3_netdev_ops; 1806 ndev->flags |= IFF_ECHO; 1807 SET_NETDEV_DEV(ndev, &pdev->dev); 1808 1809 mod->can.clock.freq = ICAN3_CAN_CLOCK; 1810 mod->can.bittiming_const = &ican3_bittiming_const; 1811 mod->can.do_set_bittiming = ican3_set_bittiming; 1812 mod->can.do_set_mode = ican3_set_mode; 1813 mod->can.do_get_berr_counter = ican3_get_berr_counter; 1814 mod->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES 1815 | CAN_CTRLMODE_BERR_REPORTING 1816 | CAN_CTRLMODE_ONE_SHOT; 1817 1818 /* find our IRQ number */ 1819 mod->irq = platform_get_irq(pdev, 0); 1820 if (mod->irq < 0) { 1821 dev_err(dev, "IRQ line not found\n"); 1822 ret = -ENODEV; 1823 goto out_free_ndev; 1824 } 1825 1826 ndev->irq = mod->irq; 1827 1828 /* get access to the MODULbus registers for this module */ 1829 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1830 if (!res) { 1831 dev_err(dev, "MODULbus registers not found\n"); 1832 ret = -ENODEV; 1833 goto out_free_ndev; 1834 } 1835 1836 mod->dpm = ioremap(res->start, resource_size(res)); 1837 if (!mod->dpm) { 1838 dev_err(dev, "MODULbus registers not ioremap\n"); 1839 ret = -ENOMEM; 1840 goto out_free_ndev; 1841 } 1842 1843 mod->dpmctrl = mod->dpm + DPM_PAGE_SIZE; 1844 1845 /* get access to the control registers for this module */ 1846 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 1847 if (!res) { 1848 dev_err(dev, "CONTROL registers not found\n"); 1849 ret = -ENODEV; 1850 goto out_iounmap_dpm; 1851 } 1852 1853 mod->ctrl = ioremap(res->start, resource_size(res)); 1854 if (!mod->ctrl) { 1855 dev_err(dev, "CONTROL registers not ioremap\n"); 1856 ret = -ENOMEM; 1857 goto out_iounmap_dpm; 1858 } 1859 1860 /* disable our IRQ, then hookup the IRQ handler */ 1861 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1862 ret = request_irq(mod->irq, ican3_irq, IRQF_SHARED, DRV_NAME, mod); 1863 if (ret) { 1864 dev_err(dev, "unable to request IRQ\n"); 1865 goto out_iounmap_ctrl; 1866 } 1867 1868 /* reset and initialize the CAN controller into fast mode */ 1869 napi_enable(&mod->napi); 1870 ret = ican3_startup_module(mod); 1871 if (ret) { 1872 dev_err(dev, "%s: unable to start CANdev\n", __func__); 1873 goto out_free_irq; 1874 } 1875 1876 /* register with the Linux CAN layer */ 1877 ret = register_candev(ndev); 1878 if (ret) { 1879 dev_err(dev, "%s: unable to register CANdev\n", __func__); 1880 goto out_free_irq; 1881 } 1882 1883 dev_info(dev, "module %d: registered CAN device\n", pdata->modno); 1884 return 0; 1885 1886out_free_irq: 1887 napi_disable(&mod->napi); 1888 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1889 free_irq(mod->irq, mod); 1890out_iounmap_ctrl: 1891 iounmap(mod->ctrl); 1892out_iounmap_dpm: 1893 iounmap(mod->dpm); 1894out_free_ndev: 1895 free_candev(ndev); 1896out_return: 1897 return ret; 1898} 1899 1900static int ican3_remove(struct platform_device *pdev) 1901{ 1902 struct net_device *ndev = platform_get_drvdata(pdev); 1903 struct ican3_dev *mod = netdev_priv(ndev); 1904 1905 /* unregister the netdevice, stop interrupts */ 1906 unregister_netdev(ndev); 1907 napi_disable(&mod->napi); 1908 iowrite8(1 << mod->num, &mod->ctrl->int_disable); 1909 free_irq(mod->irq, mod); 1910 1911 /* put the module into reset */ 1912 ican3_shutdown_module(mod); 1913 1914 /* unmap all registers */ 1915 iounmap(mod->ctrl); 1916 iounmap(mod->dpm); 1917 1918 free_candev(ndev); 1919 1920 return 0; 1921} 1922 1923static struct platform_driver ican3_driver = { 1924 .driver = { 1925 .name = DRV_NAME, 1926 .owner = THIS_MODULE, 1927 }, 1928 .probe = ican3_probe, 1929 .remove = ican3_remove, 1930}; 1931 1932module_platform_driver(ican3_driver); 1933 1934MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); 1935MODULE_DESCRIPTION("Janz MODULbus VMOD-ICAN3 Driver"); 1936MODULE_LICENSE("GPL"); 1937MODULE_ALIAS("platform:janz-ican3"); 1938