1 /* 2 * Core driver for the CC770 and AN82527 CAN controllers 3 * 4 * Copyright (C) 2009, 2011 Wolfgang Grandegger <wg@grandegger.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the version 2 of the GNU General Public License 8 * as published by the Free Software Foundation 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 17 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/kernel.h> 21 #include <linux/sched.h> 22 #include <linux/types.h> 23 #include <linux/fcntl.h> 24 #include <linux/interrupt.h> 25 #include <linux/ptrace.h> 26 #include <linux/string.h> 27 #include <linux/errno.h> 28 #include <linux/netdevice.h> 29 #include <linux/if_arp.h> 30 #include <linux/if_ether.h> 31 #include <linux/skbuff.h> 32 #include <linux/delay.h> 33 34 #include <linux/can.h> 35 #include <linux/can/dev.h> 36 #include <linux/can/error.h> 37 #include <linux/can/platform/cc770.h> 38 39 #include "cc770.h" 40 41 MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>"); 42 MODULE_LICENSE("GPL v2"); 43 MODULE_DESCRIPTION(KBUILD_MODNAME "CAN netdevice driver"); 44 45 /* 46 * The CC770 is a CAN controller from Bosch, which is 100% compatible 47 * with the AN82527 from Intel, but with "bugs" being fixed and some 48 * additional functionality, mainly: 49 * 50 * 1. RX and TX error counters are readable. 51 * 2. Support of silent (listen-only) mode. 52 * 3. Message object 15 can receive all types of frames, also RTR and EFF. 53 * 54 * Details are available from Bosch's "CC770_Product_Info_2007-01.pdf", 55 * which explains in detail the compatibility between the CC770 and the 56 * 82527. This driver use the additional functionality 3. on real CC770 57 * devices. Unfortunately, the CC770 does still not store the message 58 * identifier of received remote transmission request frames and 59 * therefore it's set to 0. 60 * 61 * The message objects 1..14 can be used for TX and RX while the message 62 * objects 15 is optimized for RX. It has a shadow register for reliable 63 * data reception under heavy bus load. Therefore it makes sense to use 64 * this message object for the needed use case. The frame type (EFF/SFF) 65 * for the message object 15 can be defined via kernel module parameter 66 * "msgobj15_eff". If not equal 0, it will receive 29-bit EFF frames, 67 * otherwise 11 bit SFF messages. 68 */ 69 static int msgobj15_eff; 70 module_param(msgobj15_eff, int, 0444); 71 MODULE_PARM_DESC(msgobj15_eff, "Extended 29-bit frames for message object 15 " 72 "(default: 11-bit standard frames)"); 73 74 static int i82527_compat; 75 module_param(i82527_compat, int, 0444); 76 MODULE_PARM_DESC(i82527_compat, "Strict Intel 82527 compatibility mode " 77 "without using additional functions"); 78 79 /* 80 * This driver uses the last 5 message objects 11..15. The definitions 81 * and structure below allows to configure and assign them to the real 82 * message object. 83 */ 84 static unsigned char cc770_obj_flags[CC770_OBJ_MAX] = { 85 [CC770_OBJ_RX0] = CC770_OBJ_FLAG_RX, 86 [CC770_OBJ_RX1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_EFF, 87 [CC770_OBJ_RX_RTR0] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR, 88 [CC770_OBJ_RX_RTR1] = CC770_OBJ_FLAG_RX | CC770_OBJ_FLAG_RTR | 89 CC770_OBJ_FLAG_EFF, 90 [CC770_OBJ_TX] = 0, 91 }; 92 93 static const struct can_bittiming_const cc770_bittiming_const = { 94 .name = KBUILD_MODNAME, 95 .tseg1_min = 1, 96 .tseg1_max = 16, 97 .tseg2_min = 1, 98 .tseg2_max = 8, 99 .sjw_max = 4, 100 .brp_min = 1, 101 .brp_max = 64, 102 .brp_inc = 1, 103 }; 104 105 static inline int intid2obj(unsigned int intid) 106 { 107 if (intid == 2) 108 return 0; 109 else 110 return MSGOBJ_LAST + 2 - intid; 111 } 112 113 static void enable_all_objs(const struct net_device *dev) 114 { 115 struct cc770_priv *priv = netdev_priv(dev); 116 u8 msgcfg; 117 unsigned char obj_flags; 118 unsigned int o, mo; 119 120 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) { 121 obj_flags = priv->obj_flags[o]; 122 mo = obj2msgobj(o); 123 124 if (obj_flags & CC770_OBJ_FLAG_RX) { 125 /* 126 * We don't need extra objects for RTR and EFF if 127 * the additional CC770 functions are enabled. 128 */ 129 if (priv->control_normal_mode & CTRL_EAF) { 130 if (o > 0) 131 continue; 132 netdev_dbg(dev, "Message object %d for " 133 "RX data, RTR, SFF and EFF\n", mo); 134 } else { 135 netdev_dbg(dev, 136 "Message object %d for RX %s %s\n", 137 mo, obj_flags & CC770_OBJ_FLAG_RTR ? 138 "RTR" : "data", 139 obj_flags & CC770_OBJ_FLAG_EFF ? 140 "EFF" : "SFF"); 141 } 142 143 if (obj_flags & CC770_OBJ_FLAG_EFF) 144 msgcfg = MSGCFG_XTD; 145 else 146 msgcfg = 0; 147 if (obj_flags & CC770_OBJ_FLAG_RTR) 148 msgcfg |= MSGCFG_DIR; 149 150 cc770_write_reg(priv, msgobj[mo].config, msgcfg); 151 cc770_write_reg(priv, msgobj[mo].ctrl0, 152 MSGVAL_SET | TXIE_RES | 153 RXIE_SET | INTPND_RES); 154 155 if (obj_flags & CC770_OBJ_FLAG_RTR) 156 cc770_write_reg(priv, msgobj[mo].ctrl1, 157 NEWDAT_RES | CPUUPD_SET | 158 TXRQST_RES | RMTPND_RES); 159 else 160 cc770_write_reg(priv, msgobj[mo].ctrl1, 161 NEWDAT_RES | MSGLST_RES | 162 TXRQST_RES | RMTPND_RES); 163 } else { 164 netdev_dbg(dev, "Message object %d for " 165 "TX data, RTR, SFF and EFF\n", mo); 166 167 cc770_write_reg(priv, msgobj[mo].ctrl1, 168 RMTPND_RES | TXRQST_RES | 169 CPUUPD_RES | NEWDAT_RES); 170 cc770_write_reg(priv, msgobj[mo].ctrl0, 171 MSGVAL_RES | TXIE_RES | 172 RXIE_RES | INTPND_RES); 173 } 174 } 175 } 176 177 static void disable_all_objs(const struct cc770_priv *priv) 178 { 179 int o, mo; 180 181 for (o = 0; o < ARRAY_SIZE(priv->obj_flags); o++) { 182 mo = obj2msgobj(o); 183 184 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) { 185 if (o > 0 && priv->control_normal_mode & CTRL_EAF) 186 continue; 187 188 cc770_write_reg(priv, msgobj[mo].ctrl1, 189 NEWDAT_RES | MSGLST_RES | 190 TXRQST_RES | RMTPND_RES); 191 cc770_write_reg(priv, msgobj[mo].ctrl0, 192 MSGVAL_RES | TXIE_RES | 193 RXIE_RES | INTPND_RES); 194 } else { 195 /* Clear message object for send */ 196 cc770_write_reg(priv, msgobj[mo].ctrl1, 197 RMTPND_RES | TXRQST_RES | 198 CPUUPD_RES | NEWDAT_RES); 199 cc770_write_reg(priv, msgobj[mo].ctrl0, 200 MSGVAL_RES | TXIE_RES | 201 RXIE_RES | INTPND_RES); 202 } 203 } 204 } 205 206 static void set_reset_mode(struct net_device *dev) 207 { 208 struct cc770_priv *priv = netdev_priv(dev); 209 210 /* Enable configuration and puts chip in bus-off, disable interrupts */ 211 cc770_write_reg(priv, control, CTRL_CCE | CTRL_INI); 212 213 priv->can.state = CAN_STATE_STOPPED; 214 215 /* Clear interrupts */ 216 cc770_read_reg(priv, interrupt); 217 218 /* Clear status register */ 219 cc770_write_reg(priv, status, 0); 220 221 /* Disable all used message objects */ 222 disable_all_objs(priv); 223 } 224 225 static void set_normal_mode(struct net_device *dev) 226 { 227 struct cc770_priv *priv = netdev_priv(dev); 228 229 /* Clear interrupts */ 230 cc770_read_reg(priv, interrupt); 231 232 /* Clear status register and pre-set last error code */ 233 cc770_write_reg(priv, status, STAT_LEC_MASK); 234 235 /* Enable all used message objects*/ 236 enable_all_objs(dev); 237 238 /* 239 * Clear bus-off, interrupts only for errors, 240 * not for status change 241 */ 242 cc770_write_reg(priv, control, priv->control_normal_mode); 243 244 priv->can.state = CAN_STATE_ERROR_ACTIVE; 245 } 246 247 static void chipset_init(struct cc770_priv *priv) 248 { 249 int mo, id, data; 250 251 /* Enable configuration and put chip in bus-off, disable interrupts */ 252 cc770_write_reg(priv, control, (CTRL_CCE | CTRL_INI)); 253 254 /* Set CLKOUT divider and slew rates */ 255 cc770_write_reg(priv, clkout, priv->clkout); 256 257 /* Configure CPU interface / CLKOUT enable */ 258 cc770_write_reg(priv, cpu_interface, priv->cpu_interface); 259 260 /* Set bus configuration */ 261 cc770_write_reg(priv, bus_config, priv->bus_config); 262 263 /* Clear interrupts */ 264 cc770_read_reg(priv, interrupt); 265 266 /* Clear status register */ 267 cc770_write_reg(priv, status, 0); 268 269 /* Clear and invalidate message objects */ 270 for (mo = MSGOBJ_FIRST; mo <= MSGOBJ_LAST; mo++) { 271 cc770_write_reg(priv, msgobj[mo].ctrl0, 272 INTPND_UNC | RXIE_RES | 273 TXIE_RES | MSGVAL_RES); 274 cc770_write_reg(priv, msgobj[mo].ctrl0, 275 INTPND_RES | RXIE_RES | 276 TXIE_RES | MSGVAL_RES); 277 cc770_write_reg(priv, msgobj[mo].ctrl1, 278 NEWDAT_RES | MSGLST_RES | 279 TXRQST_RES | RMTPND_RES); 280 for (data = 0; data < 8; data++) 281 cc770_write_reg(priv, msgobj[mo].data[data], 0); 282 for (id = 0; id < 4; id++) 283 cc770_write_reg(priv, msgobj[mo].id[id], 0); 284 cc770_write_reg(priv, msgobj[mo].config, 0); 285 } 286 287 /* Set all global ID masks to "don't care" */ 288 cc770_write_reg(priv, global_mask_std[0], 0); 289 cc770_write_reg(priv, global_mask_std[1], 0); 290 cc770_write_reg(priv, global_mask_ext[0], 0); 291 cc770_write_reg(priv, global_mask_ext[1], 0); 292 cc770_write_reg(priv, global_mask_ext[2], 0); 293 cc770_write_reg(priv, global_mask_ext[3], 0); 294 295 } 296 297 static int cc770_probe_chip(struct net_device *dev) 298 { 299 struct cc770_priv *priv = netdev_priv(dev); 300 301 /* Enable configuration, put chip in bus-off, disable ints */ 302 cc770_write_reg(priv, control, CTRL_CCE | CTRL_EAF | CTRL_INI); 303 /* Configure cpu interface / CLKOUT disable */ 304 cc770_write_reg(priv, cpu_interface, priv->cpu_interface); 305 306 /* 307 * Check if hardware reset is still inactive or maybe there 308 * is no chip in this address space 309 */ 310 if (cc770_read_reg(priv, cpu_interface) & CPUIF_RST) { 311 netdev_info(dev, "probing @0x%p failed (reset)\n", 312 priv->reg_base); 313 return -ENODEV; 314 } 315 316 /* Write and read back test pattern (some arbitrary values) */ 317 cc770_write_reg(priv, msgobj[1].data[1], 0x25); 318 cc770_write_reg(priv, msgobj[2].data[3], 0x52); 319 cc770_write_reg(priv, msgobj[10].data[6], 0xc3); 320 if ((cc770_read_reg(priv, msgobj[1].data[1]) != 0x25) || 321 (cc770_read_reg(priv, msgobj[2].data[3]) != 0x52) || 322 (cc770_read_reg(priv, msgobj[10].data[6]) != 0xc3)) { 323 netdev_info(dev, "probing @0x%p failed (pattern)\n", 324 priv->reg_base); 325 return -ENODEV; 326 } 327 328 /* Check if this chip is a CC770 supporting additional functions */ 329 if (cc770_read_reg(priv, control) & CTRL_EAF) 330 priv->control_normal_mode |= CTRL_EAF; 331 332 return 0; 333 } 334 335 static void cc770_start(struct net_device *dev) 336 { 337 struct cc770_priv *priv = netdev_priv(dev); 338 339 /* leave reset mode */ 340 if (priv->can.state != CAN_STATE_STOPPED) 341 set_reset_mode(dev); 342 343 /* leave reset mode */ 344 set_normal_mode(dev); 345 } 346 347 static int cc770_set_mode(struct net_device *dev, enum can_mode mode) 348 { 349 switch (mode) { 350 case CAN_MODE_START: 351 cc770_start(dev); 352 netif_wake_queue(dev); 353 break; 354 355 default: 356 return -EOPNOTSUPP; 357 } 358 359 return 0; 360 } 361 362 static int cc770_set_bittiming(struct net_device *dev) 363 { 364 struct cc770_priv *priv = netdev_priv(dev); 365 struct can_bittiming *bt = &priv->can.bittiming; 366 u8 btr0, btr1; 367 368 btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6); 369 btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) | 370 (((bt->phase_seg2 - 1) & 0x7) << 4); 371 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) 372 btr1 |= 0x80; 373 374 netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1); 375 376 cc770_write_reg(priv, bit_timing_0, btr0); 377 cc770_write_reg(priv, bit_timing_1, btr1); 378 379 return 0; 380 } 381 382 static int cc770_get_berr_counter(const struct net_device *dev, 383 struct can_berr_counter *bec) 384 { 385 struct cc770_priv *priv = netdev_priv(dev); 386 387 bec->txerr = cc770_read_reg(priv, tx_error_counter); 388 bec->rxerr = cc770_read_reg(priv, rx_error_counter); 389 390 return 0; 391 } 392 393 static void cc770_tx(struct net_device *dev, int mo) 394 { 395 struct cc770_priv *priv = netdev_priv(dev); 396 struct can_frame *cf = (struct can_frame *)priv->tx_skb->data; 397 u8 dlc, rtr; 398 u32 id; 399 int i; 400 401 dlc = cf->can_dlc; 402 id = cf->can_id; 403 rtr = cf->can_id & CAN_RTR_FLAG ? 0 : MSGCFG_DIR; 404 405 cc770_write_reg(priv, msgobj[mo].ctrl0, 406 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES); 407 cc770_write_reg(priv, msgobj[mo].ctrl1, 408 RMTPND_RES | TXRQST_RES | CPUUPD_SET | NEWDAT_RES); 409 410 if (id & CAN_EFF_FLAG) { 411 id &= CAN_EFF_MASK; 412 cc770_write_reg(priv, msgobj[mo].config, 413 (dlc << 4) | rtr | MSGCFG_XTD); 414 cc770_write_reg(priv, msgobj[mo].id[3], id << 3); 415 cc770_write_reg(priv, msgobj[mo].id[2], id >> 5); 416 cc770_write_reg(priv, msgobj[mo].id[1], id >> 13); 417 cc770_write_reg(priv, msgobj[mo].id[0], id >> 21); 418 } else { 419 id &= CAN_SFF_MASK; 420 cc770_write_reg(priv, msgobj[mo].config, (dlc << 4) | rtr); 421 cc770_write_reg(priv, msgobj[mo].id[0], id >> 3); 422 cc770_write_reg(priv, msgobj[mo].id[1], id << 5); 423 } 424 425 for (i = 0; i < dlc; i++) 426 cc770_write_reg(priv, msgobj[mo].data[i], cf->data[i]); 427 428 cc770_write_reg(priv, msgobj[mo].ctrl1, 429 RMTPND_UNC | TXRQST_SET | CPUUPD_RES | NEWDAT_UNC); 430 cc770_write_reg(priv, msgobj[mo].ctrl0, 431 MSGVAL_SET | TXIE_SET | RXIE_SET | INTPND_UNC); 432 } 433 434 static netdev_tx_t cc770_start_xmit(struct sk_buff *skb, struct net_device *dev) 435 { 436 struct cc770_priv *priv = netdev_priv(dev); 437 unsigned int mo = obj2msgobj(CC770_OBJ_TX); 438 439 if (can_dropped_invalid_skb(dev, skb)) 440 return NETDEV_TX_OK; 441 442 netif_stop_queue(dev); 443 444 if ((cc770_read_reg(priv, 445 msgobj[mo].ctrl1) & TXRQST_UNC) == TXRQST_SET) { 446 netdev_err(dev, "TX register is still occupied!\n"); 447 return NETDEV_TX_BUSY; 448 } 449 450 priv->tx_skb = skb; 451 cc770_tx(dev, mo); 452 453 return NETDEV_TX_OK; 454 } 455 456 static void cc770_rx(struct net_device *dev, unsigned int mo, u8 ctrl1) 457 { 458 struct cc770_priv *priv = netdev_priv(dev); 459 struct net_device_stats *stats = &dev->stats; 460 struct can_frame *cf; 461 struct sk_buff *skb; 462 u8 config; 463 u32 id; 464 int i; 465 466 skb = alloc_can_skb(dev, &cf); 467 if (!skb) 468 return; 469 470 config = cc770_read_reg(priv, msgobj[mo].config); 471 472 if (ctrl1 & RMTPND_SET) { 473 /* 474 * Unfortunately, the chip does not store the real message 475 * identifier of the received remote transmission request 476 * frame. Therefore we set it to 0. 477 */ 478 cf->can_id = CAN_RTR_FLAG; 479 if (config & MSGCFG_XTD) 480 cf->can_id |= CAN_EFF_FLAG; 481 cf->can_dlc = 0; 482 } else { 483 if (config & MSGCFG_XTD) { 484 id = cc770_read_reg(priv, msgobj[mo].id[3]); 485 id |= cc770_read_reg(priv, msgobj[mo].id[2]) << 8; 486 id |= cc770_read_reg(priv, msgobj[mo].id[1]) << 16; 487 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 24; 488 id >>= 3; 489 id |= CAN_EFF_FLAG; 490 } else { 491 id = cc770_read_reg(priv, msgobj[mo].id[1]); 492 id |= cc770_read_reg(priv, msgobj[mo].id[0]) << 8; 493 id >>= 5; 494 } 495 496 cf->can_id = id; 497 cf->can_dlc = get_can_dlc((config & 0xf0) >> 4); 498 for (i = 0; i < cf->can_dlc; i++) 499 cf->data[i] = cc770_read_reg(priv, msgobj[mo].data[i]); 500 } 501 502 stats->rx_packets++; 503 stats->rx_bytes += cf->can_dlc; 504 netif_rx(skb); 505 } 506 507 static int cc770_err(struct net_device *dev, u8 status) 508 { 509 struct cc770_priv *priv = netdev_priv(dev); 510 struct net_device_stats *stats = &dev->stats; 511 struct can_frame *cf; 512 struct sk_buff *skb; 513 u8 lec; 514 515 netdev_dbg(dev, "status interrupt (%#x)\n", status); 516 517 skb = alloc_can_err_skb(dev, &cf); 518 if (!skb) 519 return -ENOMEM; 520 521 /* Use extended functions of the CC770 */ 522 if (priv->control_normal_mode & CTRL_EAF) { 523 cf->data[6] = cc770_read_reg(priv, tx_error_counter); 524 cf->data[7] = cc770_read_reg(priv, rx_error_counter); 525 } 526 527 if (status & STAT_BOFF) { 528 /* Disable interrupts */ 529 cc770_write_reg(priv, control, CTRL_INI); 530 cf->can_id |= CAN_ERR_BUSOFF; 531 priv->can.state = CAN_STATE_BUS_OFF; 532 priv->can.can_stats.bus_off++; 533 can_bus_off(dev); 534 } else if (status & STAT_WARN) { 535 cf->can_id |= CAN_ERR_CRTL; 536 /* Only the CC770 does show error passive */ 537 if (cf->data[7] > 127) { 538 cf->data[1] = CAN_ERR_CRTL_RX_PASSIVE | 539 CAN_ERR_CRTL_TX_PASSIVE; 540 priv->can.state = CAN_STATE_ERROR_PASSIVE; 541 priv->can.can_stats.error_passive++; 542 } else { 543 cf->data[1] = CAN_ERR_CRTL_RX_WARNING | 544 CAN_ERR_CRTL_TX_WARNING; 545 priv->can.state = CAN_STATE_ERROR_WARNING; 546 priv->can.can_stats.error_warning++; 547 } 548 } else { 549 /* Back to error avtive */ 550 cf->can_id |= CAN_ERR_PROT; 551 cf->data[2] = CAN_ERR_PROT_ACTIVE; 552 priv->can.state = CAN_STATE_ERROR_ACTIVE; 553 } 554 555 lec = status & STAT_LEC_MASK; 556 if (lec < 7 && lec > 0) { 557 if (lec == STAT_LEC_ACK) { 558 cf->can_id |= CAN_ERR_ACK; 559 } else { 560 cf->can_id |= CAN_ERR_PROT; 561 switch (lec) { 562 case STAT_LEC_STUFF: 563 cf->data[2] |= CAN_ERR_PROT_STUFF; 564 break; 565 case STAT_LEC_FORM: 566 cf->data[2] |= CAN_ERR_PROT_FORM; 567 break; 568 case STAT_LEC_BIT1: 569 cf->data[2] |= CAN_ERR_PROT_BIT1; 570 break; 571 case STAT_LEC_BIT0: 572 cf->data[2] |= CAN_ERR_PROT_BIT0; 573 break; 574 case STAT_LEC_CRC: 575 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; 576 break; 577 } 578 } 579 } 580 581 582 stats->rx_packets++; 583 stats->rx_bytes += cf->can_dlc; 584 netif_rx(skb); 585 586 return 0; 587 } 588 589 static int cc770_status_interrupt(struct net_device *dev) 590 { 591 struct cc770_priv *priv = netdev_priv(dev); 592 u8 status; 593 594 status = cc770_read_reg(priv, status); 595 /* Reset the status register including RXOK and TXOK */ 596 cc770_write_reg(priv, status, STAT_LEC_MASK); 597 598 if (status & (STAT_WARN | STAT_BOFF) || 599 (status & STAT_LEC_MASK) != STAT_LEC_MASK) { 600 cc770_err(dev, status); 601 return status & STAT_BOFF; 602 } 603 604 return 0; 605 } 606 607 static void cc770_rx_interrupt(struct net_device *dev, unsigned int o) 608 { 609 struct cc770_priv *priv = netdev_priv(dev); 610 struct net_device_stats *stats = &dev->stats; 611 unsigned int mo = obj2msgobj(o); 612 u8 ctrl1; 613 int n = CC770_MAX_MSG; 614 615 while (n--) { 616 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1); 617 618 if (!(ctrl1 & NEWDAT_SET)) { 619 /* Check for RTR if additional functions are enabled */ 620 if (priv->control_normal_mode & CTRL_EAF) { 621 if (!(cc770_read_reg(priv, msgobj[mo].ctrl0) & 622 INTPND_SET)) 623 break; 624 } else { 625 break; 626 } 627 } 628 629 if (ctrl1 & MSGLST_SET) { 630 stats->rx_over_errors++; 631 stats->rx_errors++; 632 } 633 if (mo < MSGOBJ_LAST) 634 cc770_write_reg(priv, msgobj[mo].ctrl1, 635 NEWDAT_RES | MSGLST_RES | 636 TXRQST_UNC | RMTPND_UNC); 637 cc770_rx(dev, mo, ctrl1); 638 639 cc770_write_reg(priv, msgobj[mo].ctrl0, 640 MSGVAL_SET | TXIE_RES | 641 RXIE_SET | INTPND_RES); 642 cc770_write_reg(priv, msgobj[mo].ctrl1, 643 NEWDAT_RES | MSGLST_RES | 644 TXRQST_RES | RMTPND_RES); 645 } 646 } 647 648 static void cc770_rtr_interrupt(struct net_device *dev, unsigned int o) 649 { 650 struct cc770_priv *priv = netdev_priv(dev); 651 unsigned int mo = obj2msgobj(o); 652 u8 ctrl0, ctrl1; 653 int n = CC770_MAX_MSG; 654 655 while (n--) { 656 ctrl0 = cc770_read_reg(priv, msgobj[mo].ctrl0); 657 if (!(ctrl0 & INTPND_SET)) 658 break; 659 660 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1); 661 cc770_rx(dev, mo, ctrl1); 662 663 cc770_write_reg(priv, msgobj[mo].ctrl0, 664 MSGVAL_SET | TXIE_RES | 665 RXIE_SET | INTPND_RES); 666 cc770_write_reg(priv, msgobj[mo].ctrl1, 667 NEWDAT_RES | CPUUPD_SET | 668 TXRQST_RES | RMTPND_RES); 669 } 670 } 671 672 static void cc770_tx_interrupt(struct net_device *dev, unsigned int o) 673 { 674 struct cc770_priv *priv = netdev_priv(dev); 675 struct net_device_stats *stats = &dev->stats; 676 unsigned int mo = obj2msgobj(o); 677 struct can_frame *cf; 678 u8 ctrl1; 679 680 ctrl1 = cc770_read_reg(priv, msgobj[mo].ctrl1); 681 682 cc770_write_reg(priv, msgobj[mo].ctrl0, 683 MSGVAL_RES | TXIE_RES | RXIE_RES | INTPND_RES); 684 cc770_write_reg(priv, msgobj[mo].ctrl1, 685 RMTPND_RES | TXRQST_RES | MSGLST_RES | NEWDAT_RES); 686 687 if (unlikely(!priv->tx_skb)) { 688 netdev_err(dev, "missing tx skb in tx interrupt\n"); 689 return; 690 } 691 692 if (unlikely(ctrl1 & MSGLST_SET)) { 693 stats->rx_over_errors++; 694 stats->rx_errors++; 695 } 696 697 /* When the CC770 is sending an RTR message and it receives a regular 698 * message that matches the id of the RTR message, it will overwrite the 699 * outgoing message in the TX register. When this happens we must 700 * process the received message and try to transmit the outgoing skb 701 * again. 702 */ 703 if (unlikely(ctrl1 & NEWDAT_SET)) { 704 cc770_rx(dev, mo, ctrl1); 705 cc770_tx(dev, mo); 706 return; 707 } 708 709 cf = (struct can_frame *)priv->tx_skb->data; 710 stats->tx_bytes += cf->can_dlc; 711 stats->tx_packets++; 712 713 can_put_echo_skb(priv->tx_skb, dev, 0); 714 can_get_echo_skb(dev, 0); 715 priv->tx_skb = NULL; 716 717 netif_wake_queue(dev); 718 } 719 720 static irqreturn_t cc770_interrupt(int irq, void *dev_id) 721 { 722 struct net_device *dev = (struct net_device *)dev_id; 723 struct cc770_priv *priv = netdev_priv(dev); 724 u8 intid; 725 int o, n = 0; 726 727 /* Shared interrupts and IRQ off? */ 728 if (priv->can.state == CAN_STATE_STOPPED) 729 return IRQ_NONE; 730 731 if (priv->pre_irq) 732 priv->pre_irq(priv); 733 734 while (n < CC770_MAX_IRQ) { 735 /* Read the highest pending interrupt request */ 736 intid = cc770_read_reg(priv, interrupt); 737 if (!intid) 738 break; 739 n++; 740 741 if (intid == 1) { 742 /* Exit in case of bus-off */ 743 if (cc770_status_interrupt(dev)) 744 break; 745 } else { 746 o = intid2obj(intid); 747 748 if (o >= CC770_OBJ_MAX) { 749 netdev_err(dev, "Unexpected interrupt id %d\n", 750 intid); 751 continue; 752 } 753 754 if (priv->obj_flags[o] & CC770_OBJ_FLAG_RTR) 755 cc770_rtr_interrupt(dev, o); 756 else if (priv->obj_flags[o] & CC770_OBJ_FLAG_RX) 757 cc770_rx_interrupt(dev, o); 758 else 759 cc770_tx_interrupt(dev, o); 760 } 761 } 762 763 if (priv->post_irq) 764 priv->post_irq(priv); 765 766 if (n >= CC770_MAX_IRQ) 767 netdev_dbg(dev, "%d messages handled in ISR", n); 768 769 return (n) ? IRQ_HANDLED : IRQ_NONE; 770 } 771 772 static int cc770_open(struct net_device *dev) 773 { 774 struct cc770_priv *priv = netdev_priv(dev); 775 int err; 776 777 /* set chip into reset mode */ 778 set_reset_mode(dev); 779 780 /* common open */ 781 err = open_candev(dev); 782 if (err) 783 return err; 784 785 err = request_irq(dev->irq, &cc770_interrupt, priv->irq_flags, 786 dev->name, dev); 787 if (err) { 788 close_candev(dev); 789 return -EAGAIN; 790 } 791 792 /* init and start chip */ 793 cc770_start(dev); 794 795 netif_start_queue(dev); 796 797 return 0; 798 } 799 800 static int cc770_close(struct net_device *dev) 801 { 802 netif_stop_queue(dev); 803 set_reset_mode(dev); 804 805 free_irq(dev->irq, dev); 806 close_candev(dev); 807 808 return 0; 809 } 810 811 struct net_device *alloc_cc770dev(int sizeof_priv) 812 { 813 struct net_device *dev; 814 struct cc770_priv *priv; 815 816 dev = alloc_candev(sizeof(struct cc770_priv) + sizeof_priv, 817 CC770_ECHO_SKB_MAX); 818 if (!dev) 819 return NULL; 820 821 priv = netdev_priv(dev); 822 823 priv->dev = dev; 824 priv->can.bittiming_const = &cc770_bittiming_const; 825 priv->can.do_set_bittiming = cc770_set_bittiming; 826 priv->can.do_set_mode = cc770_set_mode; 827 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 828 priv->tx_skb = NULL; 829 830 memcpy(priv->obj_flags, cc770_obj_flags, sizeof(cc770_obj_flags)); 831 832 if (sizeof_priv) 833 priv->priv = (void *)priv + sizeof(struct cc770_priv); 834 835 return dev; 836 } 837 EXPORT_SYMBOL_GPL(alloc_cc770dev); 838 839 void free_cc770dev(struct net_device *dev) 840 { 841 free_candev(dev); 842 } 843 EXPORT_SYMBOL_GPL(free_cc770dev); 844 845 static const struct net_device_ops cc770_netdev_ops = { 846 .ndo_open = cc770_open, 847 .ndo_stop = cc770_close, 848 .ndo_start_xmit = cc770_start_xmit, 849 .ndo_change_mtu = can_change_mtu, 850 }; 851 852 int register_cc770dev(struct net_device *dev) 853 { 854 struct cc770_priv *priv = netdev_priv(dev); 855 int err; 856 857 err = cc770_probe_chip(dev); 858 if (err) 859 return err; 860 861 dev->netdev_ops = &cc770_netdev_ops; 862 863 dev->flags |= IFF_ECHO; /* we support local echo */ 864 865 /* Should we use additional functions? */ 866 if (!i82527_compat && priv->control_normal_mode & CTRL_EAF) { 867 priv->can.do_get_berr_counter = cc770_get_berr_counter; 868 priv->control_normal_mode = CTRL_IE | CTRL_EAF | CTRL_EIE; 869 netdev_dbg(dev, "i82527 mode with additional functions\n"); 870 } else { 871 priv->control_normal_mode = CTRL_IE | CTRL_EIE; 872 netdev_dbg(dev, "strict i82527 compatibility mode\n"); 873 } 874 875 chipset_init(priv); 876 set_reset_mode(dev); 877 878 return register_candev(dev); 879 } 880 EXPORT_SYMBOL_GPL(register_cc770dev); 881 882 void unregister_cc770dev(struct net_device *dev) 883 { 884 set_reset_mode(dev); 885 unregister_candev(dev); 886 } 887 EXPORT_SYMBOL_GPL(unregister_cc770dev); 888 889 static __init int cc770_init(void) 890 { 891 if (msgobj15_eff) { 892 cc770_obj_flags[CC770_OBJ_RX0] |= CC770_OBJ_FLAG_EFF; 893 cc770_obj_flags[CC770_OBJ_RX1] &= ~CC770_OBJ_FLAG_EFF; 894 } 895 896 pr_info("CAN netdevice driver\n"); 897 898 return 0; 899 } 900 module_init(cc770_init); 901 902 static __exit void cc770_exit(void) 903 { 904 pr_info("driver removed\n"); 905 } 906 module_exit(cc770_exit); 907