1 /* 2 * TI HECC (CAN) device driver 3 * 4 * This driver supports TI's HECC (High End CAN Controller module) and the 5 * specs for the same is available at <http://www.ti.com> 6 * 7 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/ 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation version 2. 12 * 13 * This program is distributed as is WITHOUT ANY WARRANTY of any 14 * kind, whether express or implied; without even the implied warranty 15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 */ 19 20 /* 21 * Your platform definitions should specify module ram offsets and interrupt 22 * number to use as follows: 23 * 24 * static struct ti_hecc_platform_data am3517_evm_hecc_pdata = { 25 * .scc_hecc_offset = 0, 26 * .scc_ram_offset = 0x3000, 27 * .hecc_ram_offset = 0x3000, 28 * .mbx_offset = 0x2000, 29 * .int_line = 0, 30 * .revision = 1, 31 * .transceiver_switch = hecc_phy_control, 32 * }; 33 * 34 * Please see include/linux/can/platform/ti_hecc.h for description of 35 * above fields. 36 * 37 */ 38 39 #include <linux/module.h> 40 #include <linux/init.h> 41 #include <linux/kernel.h> 42 #include <linux/types.h> 43 #include <linux/interrupt.h> 44 #include <linux/errno.h> 45 #include <linux/netdevice.h> 46 #include <linux/skbuff.h> 47 #include <linux/platform_device.h> 48 #include <linux/clk.h> 49 #include <linux/io.h> 50 51 #include <linux/can/dev.h> 52 #include <linux/can/error.h> 53 #include <linux/can/led.h> 54 #include <linux/can/platform/ti_hecc.h> 55 56 #define DRV_NAME "ti_hecc" 57 #define HECC_MODULE_VERSION "0.7" 58 MODULE_VERSION(HECC_MODULE_VERSION); 59 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION 60 61 /* TX / RX Mailbox Configuration */ 62 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */ 63 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */ 64 65 /* 66 * Important Note: TX mailbox configuration 67 * TX mailboxes should be restricted to the number of SKB buffers to avoid 68 * maintaining SKB buffers separately. TX mailboxes should be a power of 2 69 * for the mailbox logic to work. Top mailbox numbers are reserved for RX 70 * and lower mailboxes for TX. 71 * 72 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT 73 * 4 (default) 2 74 * 8 3 75 * 16 4 76 */ 77 #define HECC_MB_TX_SHIFT 2 /* as per table above */ 78 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT) 79 80 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT) 81 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT) 82 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1) 83 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK) 84 #define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1)) 85 #define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX 86 87 /* 88 * Important Note: RX mailbox configuration 89 * RX mailboxes are further logically split into two - main and buffer 90 * mailboxes. The goal is to get all packets into main mailboxes as 91 * driven by mailbox number and receive priority (higher to lower) and 92 * buffer mailboxes are used to receive pkts while main mailboxes are being 93 * processed. This ensures in-order packet reception. 94 * 95 * Here are the recommended values for buffer mailbox. Note that RX mailboxes 96 * start after TX mailboxes: 97 * 98 * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes 99 * 28 12 8 100 * 16 20 4 101 */ 102 103 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) 104 #define HECC_RX_BUFFER_MBOX 12 /* as per table above */ 105 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) 106 #define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1)) 107 108 /* TI HECC module registers */ 109 #define HECC_CANME 0x0 /* Mailbox enable */ 110 #define HECC_CANMD 0x4 /* Mailbox direction */ 111 #define HECC_CANTRS 0x8 /* Transmit request set */ 112 #define HECC_CANTRR 0xC /* Transmit request */ 113 #define HECC_CANTA 0x10 /* Transmission acknowledge */ 114 #define HECC_CANAA 0x14 /* Abort acknowledge */ 115 #define HECC_CANRMP 0x18 /* Receive message pending */ 116 #define HECC_CANRML 0x1C /* Remote message lost */ 117 #define HECC_CANRFP 0x20 /* Remote frame pending */ 118 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */ 119 #define HECC_CANMC 0x28 /* Master control */ 120 #define HECC_CANBTC 0x2C /* Bit timing configuration */ 121 #define HECC_CANES 0x30 /* Error and status */ 122 #define HECC_CANTEC 0x34 /* Transmit error counter */ 123 #define HECC_CANREC 0x38 /* Receive error counter */ 124 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */ 125 #define HECC_CANGIM 0x40 /* Global interrupt mask */ 126 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */ 127 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */ 128 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */ 129 #define HECC_CANOPC 0x50 /* Overwrite protection control */ 130 #define HECC_CANTIOC 0x54 /* Transmit I/O control */ 131 #define HECC_CANRIOC 0x58 /* Receive I/O control */ 132 #define HECC_CANLNT 0x5C /* HECC only: Local network time */ 133 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */ 134 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */ 135 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */ 136 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */ 137 138 /* Mailbox registers */ 139 #define HECC_CANMID 0x0 140 #define HECC_CANMCF 0x4 141 #define HECC_CANMDL 0x8 142 #define HECC_CANMDH 0xC 143 144 #define HECC_SET_REG 0xFFFFFFFF 145 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */ 146 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */ 147 148 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */ 149 #define HECC_CANMC_CCR BIT(12) /* Change config request */ 150 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */ 151 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */ 152 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */ 153 #define HECC_CANMC_SRES BIT(5) /* Software reset */ 154 155 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */ 156 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */ 157 158 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */ 159 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */ 160 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */ 161 162 #define HECC_CANES_FE BIT(24) /* form error */ 163 #define HECC_CANES_BE BIT(23) /* bit error */ 164 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */ 165 #define HECC_CANES_CRCE BIT(21) /* CRC error */ 166 #define HECC_CANES_SE BIT(20) /* stuff bit error */ 167 #define HECC_CANES_ACKE BIT(19) /* ack error */ 168 #define HECC_CANES_BO BIT(18) /* Bus off status */ 169 #define HECC_CANES_EP BIT(17) /* Error passive status */ 170 #define HECC_CANES_EW BIT(16) /* Error warning status */ 171 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */ 172 #define HECC_CANES_CCE BIT(4) /* Change config enabled */ 173 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */ 174 175 #define HECC_CANBTC_SAM BIT(7) /* sample points */ 176 177 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\ 178 HECC_CANES_CRCE | HECC_CANES_SE |\ 179 HECC_CANES_ACKE) 180 181 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */ 182 183 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */ 184 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */ 185 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */ 186 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */ 187 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */ 188 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */ 189 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */ 190 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */ 191 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */ 192 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */ 193 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */ 194 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */ 195 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */ 196 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */ 197 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */ 198 199 /* CAN Bittiming constants as per HECC specs */ 200 static const struct can_bittiming_const ti_hecc_bittiming_const = { 201 .name = DRV_NAME, 202 .tseg1_min = 1, 203 .tseg1_max = 16, 204 .tseg2_min = 1, 205 .tseg2_max = 8, 206 .sjw_max = 4, 207 .brp_min = 1, 208 .brp_max = 256, 209 .brp_inc = 1, 210 }; 211 212 struct ti_hecc_priv { 213 struct can_priv can; /* MUST be first member/field */ 214 struct napi_struct napi; 215 struct net_device *ndev; 216 struct clk *clk; 217 void __iomem *base; 218 u32 scc_ram_offset; 219 u32 hecc_ram_offset; 220 u32 mbx_offset; 221 u32 int_line; 222 spinlock_t mbx_lock; /* CANME register needs protection */ 223 u32 tx_head; 224 u32 tx_tail; 225 u32 rx_next; 226 void (*transceiver_switch)(int); 227 }; 228 229 static inline int get_tx_head_mb(struct ti_hecc_priv *priv) 230 { 231 return priv->tx_head & HECC_TX_MB_MASK; 232 } 233 234 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv) 235 { 236 return priv->tx_tail & HECC_TX_MB_MASK; 237 } 238 239 static inline int get_tx_head_prio(struct ti_hecc_priv *priv) 240 { 241 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO; 242 } 243 244 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val) 245 { 246 __raw_writel(val, priv->base + priv->hecc_ram_offset + mbxno * 4); 247 } 248 249 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, 250 u32 reg, u32 val) 251 { 252 __raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 + 253 reg); 254 } 255 256 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) 257 { 258 return __raw_readl(priv->base + priv->mbx_offset + mbxno * 0x10 + 259 reg); 260 } 261 262 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val) 263 { 264 __raw_writel(val, priv->base + reg); 265 } 266 267 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg) 268 { 269 return __raw_readl(priv->base + reg); 270 } 271 272 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg, 273 u32 bit_mask) 274 { 275 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask); 276 } 277 278 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg, 279 u32 bit_mask) 280 { 281 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask); 282 } 283 284 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask) 285 { 286 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0; 287 } 288 289 static int ti_hecc_get_state(const struct net_device *ndev, 290 enum can_state *state) 291 { 292 struct ti_hecc_priv *priv = netdev_priv(ndev); 293 294 *state = priv->can.state; 295 return 0; 296 } 297 298 static int ti_hecc_set_btc(struct ti_hecc_priv *priv) 299 { 300 struct can_bittiming *bit_timing = &priv->can.bittiming; 301 u32 can_btc; 302 303 can_btc = (bit_timing->phase_seg2 - 1) & 0x7; 304 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1) 305 & 0xF) << 3; 306 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) { 307 if (bit_timing->brp > 4) 308 can_btc |= HECC_CANBTC_SAM; 309 else 310 netdev_warn(priv->ndev, "WARN: Triple" 311 "sampling not set due to h/w limitations"); 312 } 313 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8; 314 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16; 315 316 /* ERM being set to 0 by default meaning resync at falling edge */ 317 318 hecc_write(priv, HECC_CANBTC, can_btc); 319 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc); 320 321 return 0; 322 } 323 324 static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv, 325 int on) 326 { 327 if (priv->transceiver_switch) 328 priv->transceiver_switch(on); 329 } 330 331 static void ti_hecc_reset(struct net_device *ndev) 332 { 333 u32 cnt; 334 struct ti_hecc_priv *priv = netdev_priv(ndev); 335 336 netdev_dbg(ndev, "resetting hecc ...\n"); 337 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES); 338 339 /* Set change control request and wait till enabled */ 340 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 341 342 /* 343 * INFO: It has been observed that at times CCE bit may not be 344 * set and hw seems to be ok even if this bit is not set so 345 * timing out with a timing of 1ms to respect the specs 346 */ 347 cnt = HECC_CCE_WAIT_COUNT; 348 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 349 --cnt; 350 udelay(10); 351 } 352 353 /* 354 * Note: On HECC, BTC can be programmed only in initialization mode, so 355 * it is expected that the can bittiming parameters are set via ip 356 * utility before the device is opened 357 */ 358 ti_hecc_set_btc(priv); 359 360 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */ 361 hecc_write(priv, HECC_CANMC, 0); 362 363 /* 364 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on 365 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO); 366 */ 367 368 /* 369 * INFO: It has been observed that at times CCE bit may not be 370 * set and hw seems to be ok even if this bit is not set so 371 */ 372 cnt = HECC_CCE_WAIT_COUNT; 373 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 374 --cnt; 375 udelay(10); 376 } 377 378 /* Enable TX and RX I/O Control pins */ 379 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN); 380 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN); 381 382 /* Clear registers for clean operation */ 383 hecc_write(priv, HECC_CANTA, HECC_SET_REG); 384 hecc_write(priv, HECC_CANRMP, HECC_SET_REG); 385 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 386 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 387 hecc_write(priv, HECC_CANME, 0); 388 hecc_write(priv, HECC_CANMD, 0); 389 390 /* SCC compat mode NOT supported (and not needed too) */ 391 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM); 392 } 393 394 static void ti_hecc_start(struct net_device *ndev) 395 { 396 struct ti_hecc_priv *priv = netdev_priv(ndev); 397 u32 cnt, mbxno, mbx_mask; 398 399 /* put HECC in initialization mode and set btc */ 400 ti_hecc_reset(ndev); 401 402 priv->tx_head = priv->tx_tail = HECC_TX_MASK; 403 priv->rx_next = HECC_RX_FIRST_MBOX; 404 405 /* Enable local and global acceptance mask registers */ 406 hecc_write(priv, HECC_CANGAM, HECC_SET_REG); 407 408 /* Prepare configured mailboxes to receive messages */ 409 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) { 410 mbxno = HECC_MAX_MAILBOXES - 1 - cnt; 411 mbx_mask = BIT(mbxno); 412 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 413 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME); 414 hecc_write_lam(priv, mbxno, HECC_SET_REG); 415 hecc_set_bit(priv, HECC_CANMD, mbx_mask); 416 hecc_set_bit(priv, HECC_CANME, mbx_mask); 417 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 418 } 419 420 /* Prevent message over-write & Enable interrupts */ 421 hecc_write(priv, HECC_CANOPC, HECC_SET_REG); 422 if (priv->int_line) { 423 hecc_write(priv, HECC_CANMIL, HECC_SET_REG); 424 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK | 425 HECC_CANGIM_I1EN | HECC_CANGIM_SIL); 426 } else { 427 hecc_write(priv, HECC_CANMIL, 0); 428 hecc_write(priv, HECC_CANGIM, 429 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN); 430 } 431 priv->can.state = CAN_STATE_ERROR_ACTIVE; 432 } 433 434 static void ti_hecc_stop(struct net_device *ndev) 435 { 436 struct ti_hecc_priv *priv = netdev_priv(ndev); 437 438 /* Disable interrupts and disable mailboxes */ 439 hecc_write(priv, HECC_CANGIM, 0); 440 hecc_write(priv, HECC_CANMIM, 0); 441 hecc_write(priv, HECC_CANME, 0); 442 priv->can.state = CAN_STATE_STOPPED; 443 } 444 445 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode) 446 { 447 int ret = 0; 448 449 switch (mode) { 450 case CAN_MODE_START: 451 ti_hecc_start(ndev); 452 netif_wake_queue(ndev); 453 break; 454 default: 455 ret = -EOPNOTSUPP; 456 break; 457 } 458 459 return ret; 460 } 461 462 static int ti_hecc_get_berr_counter(const struct net_device *ndev, 463 struct can_berr_counter *bec) 464 { 465 struct ti_hecc_priv *priv = netdev_priv(ndev); 466 467 bec->txerr = hecc_read(priv, HECC_CANTEC); 468 bec->rxerr = hecc_read(priv, HECC_CANREC); 469 470 return 0; 471 } 472 473 /* 474 * ti_hecc_xmit: HECC Transmit 475 * 476 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the 477 * priority of the mailbox for tranmission is dependent upon priority setting 478 * field in mailbox registers. The mailbox with highest value in priority field 479 * is transmitted first. Only when two mailboxes have the same value in 480 * priority field the highest numbered mailbox is transmitted first. 481 * 482 * To utilize the HECC priority feature as described above we start with the 483 * highest numbered mailbox with highest priority level and move on to the next 484 * mailbox with the same priority level and so on. Once we loop through all the 485 * transmit mailboxes we choose the next priority level (lower) and so on 486 * until we reach the lowest priority level on the lowest numbered mailbox 487 * when we stop transmission until all mailboxes are transmitted and then 488 * restart at highest numbered mailbox with highest priority. 489 * 490 * Two counters (head and tail) are used to track the next mailbox to transmit 491 * and to track the echo buffer for already transmitted mailbox. The queue 492 * is stopped when all the mailboxes are busy or when there is a priority 493 * value roll-over happens. 494 */ 495 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev) 496 { 497 struct ti_hecc_priv *priv = netdev_priv(ndev); 498 struct can_frame *cf = (struct can_frame *)skb->data; 499 u32 mbxno, mbx_mask, data; 500 unsigned long flags; 501 502 if (can_dropped_invalid_skb(ndev, skb)) 503 return NETDEV_TX_OK; 504 505 mbxno = get_tx_head_mb(priv); 506 mbx_mask = BIT(mbxno); 507 spin_lock_irqsave(&priv->mbx_lock, flags); 508 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) { 509 spin_unlock_irqrestore(&priv->mbx_lock, flags); 510 netif_stop_queue(ndev); 511 netdev_err(priv->ndev, 512 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n", 513 priv->tx_head, priv->tx_tail); 514 return NETDEV_TX_BUSY; 515 } 516 spin_unlock_irqrestore(&priv->mbx_lock, flags); 517 518 /* Prepare mailbox for transmission */ 519 data = cf->can_dlc | (get_tx_head_prio(priv) << 8); 520 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ 521 data |= HECC_CANMCF_RTR; 522 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data); 523 524 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ 525 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE; 526 else /* Standard frame format */ 527 data = (cf->can_id & CAN_SFF_MASK) << 18; 528 hecc_write_mbx(priv, mbxno, HECC_CANMID, data); 529 hecc_write_mbx(priv, mbxno, HECC_CANMDL, 530 be32_to_cpu(*(u32 *)(cf->data))); 531 if (cf->can_dlc > 4) 532 hecc_write_mbx(priv, mbxno, HECC_CANMDH, 533 be32_to_cpu(*(u32 *)(cf->data + 4))); 534 else 535 *(u32 *)(cf->data + 4) = 0; 536 can_put_echo_skb(skb, ndev, mbxno); 537 538 spin_lock_irqsave(&priv->mbx_lock, flags); 539 --priv->tx_head; 540 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) || 541 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) { 542 netif_stop_queue(ndev); 543 } 544 hecc_set_bit(priv, HECC_CANME, mbx_mask); 545 spin_unlock_irqrestore(&priv->mbx_lock, flags); 546 547 hecc_clear_bit(priv, HECC_CANMD, mbx_mask); 548 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 549 hecc_write(priv, HECC_CANTRS, mbx_mask); 550 551 return NETDEV_TX_OK; 552 } 553 554 static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno) 555 { 556 struct net_device_stats *stats = &priv->ndev->stats; 557 struct can_frame *cf; 558 struct sk_buff *skb; 559 u32 data, mbx_mask; 560 unsigned long flags; 561 562 skb = alloc_can_skb(priv->ndev, &cf); 563 if (!skb) { 564 if (printk_ratelimit()) 565 netdev_err(priv->ndev, 566 "ti_hecc_rx_pkt: alloc_can_skb() failed\n"); 567 return -ENOMEM; 568 } 569 570 mbx_mask = BIT(mbxno); 571 data = hecc_read_mbx(priv, mbxno, HECC_CANMID); 572 if (data & HECC_CANMID_IDE) 573 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; 574 else 575 cf->can_id = (data >> 18) & CAN_SFF_MASK; 576 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF); 577 if (data & HECC_CANMCF_RTR) 578 cf->can_id |= CAN_RTR_FLAG; 579 cf->can_dlc = get_can_dlc(data & 0xF); 580 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); 581 *(u32 *)(cf->data) = cpu_to_be32(data); 582 if (cf->can_dlc > 4) { 583 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); 584 *(u32 *)(cf->data + 4) = cpu_to_be32(data); 585 } else { 586 *(u32 *)(cf->data + 4) = 0; 587 } 588 spin_lock_irqsave(&priv->mbx_lock, flags); 589 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 590 hecc_write(priv, HECC_CANRMP, mbx_mask); 591 /* enable mailbox only if it is part of rx buffer mailboxes */ 592 if (priv->rx_next < HECC_RX_BUFFER_MBOX) 593 hecc_set_bit(priv, HECC_CANME, mbx_mask); 594 spin_unlock_irqrestore(&priv->mbx_lock, flags); 595 596 stats->rx_bytes += cf->can_dlc; 597 can_led_event(priv->ndev, CAN_LED_EVENT_RX); 598 netif_receive_skb(skb); 599 stats->rx_packets++; 600 601 return 0; 602 } 603 604 /* 605 * ti_hecc_rx_poll - HECC receive pkts 606 * 607 * The receive mailboxes start from highest numbered mailbox till last xmit 608 * mailbox. On CAN frame reception the hardware places the data into highest 609 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes 610 * have same filtering (ALL CAN frames) packets will arrive in the highest 611 * available RX mailbox and we need to ensure in-order packet reception. 612 * 613 * To ensure the packets are received in the right order we logically divide 614 * the RX mailboxes into main and buffer mailboxes. Packets are received as per 615 * mailbox priotity (higher to lower) in the main bank and once it is full we 616 * disable further reception into main mailboxes. While the main mailboxes are 617 * processed in NAPI, further packets are received in buffer mailboxes. 618 * 619 * We maintain a RX next mailbox counter to process packets and once all main 620 * mailboxe packets are passed to the upper stack we enable all of them but 621 * continue to process packets received in buffer mailboxes. With each packet 622 * received from buffer mailbox we enable it immediately so as to handle the 623 * overflow from higher mailboxes. 624 */ 625 static int ti_hecc_rx_poll(struct napi_struct *napi, int quota) 626 { 627 struct net_device *ndev = napi->dev; 628 struct ti_hecc_priv *priv = netdev_priv(ndev); 629 u32 num_pkts = 0; 630 u32 mbx_mask; 631 unsigned long pending_pkts, flags; 632 633 if (!netif_running(ndev)) 634 return 0; 635 636 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) && 637 num_pkts < quota) { 638 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */ 639 if (mbx_mask & pending_pkts) { 640 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0) 641 return num_pkts; 642 ++num_pkts; 643 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) { 644 break; /* pkt not received yet */ 645 } 646 --priv->rx_next; 647 if (priv->rx_next == HECC_RX_BUFFER_MBOX) { 648 /* enable high bank mailboxes */ 649 spin_lock_irqsave(&priv->mbx_lock, flags); 650 mbx_mask = hecc_read(priv, HECC_CANME); 651 mbx_mask |= HECC_RX_HIGH_MBOX_MASK; 652 hecc_write(priv, HECC_CANME, mbx_mask); 653 spin_unlock_irqrestore(&priv->mbx_lock, flags); 654 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) { 655 priv->rx_next = HECC_RX_FIRST_MBOX; 656 break; 657 } 658 } 659 660 /* Enable packet interrupt if all pkts are handled */ 661 if (hecc_read(priv, HECC_CANRMP) == 0) { 662 napi_complete(napi); 663 /* Re-enable RX mailbox interrupts */ 664 mbx_mask = hecc_read(priv, HECC_CANMIM); 665 mbx_mask |= HECC_TX_MBOX_MASK; 666 hecc_write(priv, HECC_CANMIM, mbx_mask); 667 } 668 669 return num_pkts; 670 } 671 672 static int ti_hecc_error(struct net_device *ndev, int int_status, 673 int err_status) 674 { 675 struct ti_hecc_priv *priv = netdev_priv(ndev); 676 struct net_device_stats *stats = &ndev->stats; 677 struct can_frame *cf; 678 struct sk_buff *skb; 679 680 /* propagate the error condition to the can stack */ 681 skb = alloc_can_err_skb(ndev, &cf); 682 if (!skb) { 683 if (printk_ratelimit()) 684 netdev_err(priv->ndev, 685 "ti_hecc_error: alloc_can_err_skb() failed\n"); 686 return -ENOMEM; 687 } 688 689 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */ 690 if ((int_status & HECC_CANGIF_BOIF) == 0) { 691 priv->can.state = CAN_STATE_ERROR_WARNING; 692 ++priv->can.can_stats.error_warning; 693 cf->can_id |= CAN_ERR_CRTL; 694 if (hecc_read(priv, HECC_CANTEC) > 96) 695 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING; 696 if (hecc_read(priv, HECC_CANREC) > 96) 697 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING; 698 } 699 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW); 700 netdev_dbg(priv->ndev, "Error Warning interrupt\n"); 701 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 702 } 703 704 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */ 705 if ((int_status & HECC_CANGIF_BOIF) == 0) { 706 priv->can.state = CAN_STATE_ERROR_PASSIVE; 707 ++priv->can.can_stats.error_passive; 708 cf->can_id |= CAN_ERR_CRTL; 709 if (hecc_read(priv, HECC_CANTEC) > 127) 710 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; 711 if (hecc_read(priv, HECC_CANREC) > 127) 712 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; 713 } 714 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP); 715 netdev_dbg(priv->ndev, "Error passive interrupt\n"); 716 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 717 } 718 719 /* 720 * Need to check busoff condition in error status register too to 721 * ensure warning interrupts don't hog the system 722 */ 723 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) { 724 priv->can.state = CAN_STATE_BUS_OFF; 725 cf->can_id |= CAN_ERR_BUSOFF; 726 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO); 727 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 728 /* Disable all interrupts in bus-off to avoid int hog */ 729 hecc_write(priv, HECC_CANGIM, 0); 730 can_bus_off(ndev); 731 } 732 733 if (err_status & HECC_BUS_ERROR) { 734 ++priv->can.can_stats.bus_error; 735 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; 736 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 737 if (err_status & HECC_CANES_FE) { 738 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE); 739 cf->data[2] |= CAN_ERR_PROT_FORM; 740 } 741 if (err_status & HECC_CANES_BE) { 742 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE); 743 cf->data[2] |= CAN_ERR_PROT_BIT; 744 } 745 if (err_status & HECC_CANES_SE) { 746 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE); 747 cf->data[2] |= CAN_ERR_PROT_STUFF; 748 } 749 if (err_status & HECC_CANES_CRCE) { 750 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE); 751 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ | 752 CAN_ERR_PROT_LOC_CRC_DEL; 753 } 754 if (err_status & HECC_CANES_ACKE) { 755 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE); 756 cf->data[3] |= CAN_ERR_PROT_LOC_ACK | 757 CAN_ERR_PROT_LOC_ACK_DEL; 758 } 759 } 760 761 netif_rx(skb); 762 stats->rx_packets++; 763 stats->rx_bytes += cf->can_dlc; 764 765 return 0; 766 } 767 768 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id) 769 { 770 struct net_device *ndev = (struct net_device *)dev_id; 771 struct ti_hecc_priv *priv = netdev_priv(ndev); 772 struct net_device_stats *stats = &ndev->stats; 773 u32 mbxno, mbx_mask, int_status, err_status; 774 unsigned long ack, flags; 775 776 int_status = hecc_read(priv, 777 (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0); 778 779 if (!int_status) 780 return IRQ_NONE; 781 782 err_status = hecc_read(priv, HECC_CANES); 783 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO | 784 HECC_CANES_EP | HECC_CANES_EW)) 785 ti_hecc_error(ndev, int_status, err_status); 786 787 if (int_status & HECC_CANGIF_GMIF) { 788 while (priv->tx_tail - priv->tx_head > 0) { 789 mbxno = get_tx_tail_mb(priv); 790 mbx_mask = BIT(mbxno); 791 if (!(mbx_mask & hecc_read(priv, HECC_CANTA))) 792 break; 793 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask); 794 hecc_write(priv, HECC_CANTA, mbx_mask); 795 spin_lock_irqsave(&priv->mbx_lock, flags); 796 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 797 spin_unlock_irqrestore(&priv->mbx_lock, flags); 798 stats->tx_bytes += hecc_read_mbx(priv, mbxno, 799 HECC_CANMCF) & 0xF; 800 stats->tx_packets++; 801 can_led_event(ndev, CAN_LED_EVENT_TX); 802 can_get_echo_skb(ndev, mbxno); 803 --priv->tx_tail; 804 } 805 806 /* restart queue if wrap-up or if queue stalled on last pkt */ 807 if (((priv->tx_head == priv->tx_tail) && 808 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) || 809 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) && 810 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK))) 811 netif_wake_queue(ndev); 812 813 /* Disable RX mailbox interrupts and let NAPI reenable them */ 814 if (hecc_read(priv, HECC_CANRMP)) { 815 ack = hecc_read(priv, HECC_CANMIM); 816 ack &= BIT(HECC_MAX_TX_MBOX) - 1; 817 hecc_write(priv, HECC_CANMIM, ack); 818 napi_schedule(&priv->napi); 819 } 820 } 821 822 /* clear all interrupt conditions - read back to avoid spurious ints */ 823 if (priv->int_line) { 824 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 825 int_status = hecc_read(priv, HECC_CANGIF1); 826 } else { 827 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 828 int_status = hecc_read(priv, HECC_CANGIF0); 829 } 830 831 return IRQ_HANDLED; 832 } 833 834 static int ti_hecc_open(struct net_device *ndev) 835 { 836 struct ti_hecc_priv *priv = netdev_priv(ndev); 837 int err; 838 839 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED, 840 ndev->name, ndev); 841 if (err) { 842 netdev_err(ndev, "error requesting interrupt\n"); 843 return err; 844 } 845 846 ti_hecc_transceiver_switch(priv, 1); 847 848 /* Open common can device */ 849 err = open_candev(ndev); 850 if (err) { 851 netdev_err(ndev, "open_candev() failed %d\n", err); 852 ti_hecc_transceiver_switch(priv, 0); 853 free_irq(ndev->irq, ndev); 854 return err; 855 } 856 857 can_led_event(ndev, CAN_LED_EVENT_OPEN); 858 859 ti_hecc_start(ndev); 860 napi_enable(&priv->napi); 861 netif_start_queue(ndev); 862 863 return 0; 864 } 865 866 static int ti_hecc_close(struct net_device *ndev) 867 { 868 struct ti_hecc_priv *priv = netdev_priv(ndev); 869 870 netif_stop_queue(ndev); 871 napi_disable(&priv->napi); 872 ti_hecc_stop(ndev); 873 free_irq(ndev->irq, ndev); 874 close_candev(ndev); 875 ti_hecc_transceiver_switch(priv, 0); 876 877 can_led_event(ndev, CAN_LED_EVENT_STOP); 878 879 return 0; 880 } 881 882 static const struct net_device_ops ti_hecc_netdev_ops = { 883 .ndo_open = ti_hecc_open, 884 .ndo_stop = ti_hecc_close, 885 .ndo_start_xmit = ti_hecc_xmit, 886 }; 887 888 static int ti_hecc_probe(struct platform_device *pdev) 889 { 890 struct net_device *ndev = (struct net_device *)0; 891 struct ti_hecc_priv *priv; 892 struct ti_hecc_platform_data *pdata; 893 struct resource *mem, *irq; 894 void __iomem *addr; 895 int err = -ENODEV; 896 897 pdata = pdev->dev.platform_data; 898 if (!pdata) { 899 dev_err(&pdev->dev, "No platform data\n"); 900 goto probe_exit; 901 } 902 903 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 904 if (!mem) { 905 dev_err(&pdev->dev, "No mem resources\n"); 906 goto probe_exit; 907 } 908 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 909 if (!irq) { 910 dev_err(&pdev->dev, "No irq resource\n"); 911 goto probe_exit; 912 } 913 if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) { 914 dev_err(&pdev->dev, "HECC region already claimed\n"); 915 err = -EBUSY; 916 goto probe_exit; 917 } 918 addr = ioremap(mem->start, resource_size(mem)); 919 if (!addr) { 920 dev_err(&pdev->dev, "ioremap failed\n"); 921 err = -ENOMEM; 922 goto probe_exit_free_region; 923 } 924 925 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); 926 if (!ndev) { 927 dev_err(&pdev->dev, "alloc_candev failed\n"); 928 err = -ENOMEM; 929 goto probe_exit_iounmap; 930 } 931 932 priv = netdev_priv(ndev); 933 priv->ndev = ndev; 934 priv->base = addr; 935 priv->scc_ram_offset = pdata->scc_ram_offset; 936 priv->hecc_ram_offset = pdata->hecc_ram_offset; 937 priv->mbx_offset = pdata->mbx_offset; 938 priv->int_line = pdata->int_line; 939 priv->transceiver_switch = pdata->transceiver_switch; 940 941 priv->can.bittiming_const = &ti_hecc_bittiming_const; 942 priv->can.do_set_mode = ti_hecc_do_set_mode; 943 priv->can.do_get_state = ti_hecc_get_state; 944 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter; 945 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 946 947 spin_lock_init(&priv->mbx_lock); 948 ndev->irq = irq->start; 949 ndev->flags |= IFF_ECHO; 950 platform_set_drvdata(pdev, ndev); 951 SET_NETDEV_DEV(ndev, &pdev->dev); 952 ndev->netdev_ops = &ti_hecc_netdev_ops; 953 954 priv->clk = clk_get(&pdev->dev, "hecc_ck"); 955 if (IS_ERR(priv->clk)) { 956 dev_err(&pdev->dev, "No clock available\n"); 957 err = PTR_ERR(priv->clk); 958 priv->clk = NULL; 959 goto probe_exit_candev; 960 } 961 priv->can.clock.freq = clk_get_rate(priv->clk); 962 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll, 963 HECC_DEF_NAPI_WEIGHT); 964 965 clk_enable(priv->clk); 966 err = register_candev(ndev); 967 if (err) { 968 dev_err(&pdev->dev, "register_candev() failed\n"); 969 goto probe_exit_clk; 970 } 971 972 devm_can_led_init(ndev); 973 974 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", 975 priv->base, (u32) ndev->irq); 976 977 return 0; 978 979 probe_exit_clk: 980 clk_put(priv->clk); 981 probe_exit_candev: 982 free_candev(ndev); 983 probe_exit_iounmap: 984 iounmap(addr); 985 probe_exit_free_region: 986 release_mem_region(mem->start, resource_size(mem)); 987 probe_exit: 988 return err; 989 } 990 991 static int ti_hecc_remove(struct platform_device *pdev) 992 { 993 struct resource *res; 994 struct net_device *ndev = platform_get_drvdata(pdev); 995 struct ti_hecc_priv *priv = netdev_priv(ndev); 996 997 unregister_candev(ndev); 998 clk_disable(priv->clk); 999 clk_put(priv->clk); 1000 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1001 iounmap(priv->base); 1002 release_mem_region(res->start, resource_size(res)); 1003 free_candev(ndev); 1004 1005 return 0; 1006 } 1007 1008 1009 #ifdef CONFIG_PM 1010 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state) 1011 { 1012 struct net_device *dev = platform_get_drvdata(pdev); 1013 struct ti_hecc_priv *priv = netdev_priv(dev); 1014 1015 if (netif_running(dev)) { 1016 netif_stop_queue(dev); 1017 netif_device_detach(dev); 1018 } 1019 1020 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1021 priv->can.state = CAN_STATE_SLEEPING; 1022 1023 clk_disable(priv->clk); 1024 1025 return 0; 1026 } 1027 1028 static int ti_hecc_resume(struct platform_device *pdev) 1029 { 1030 struct net_device *dev = platform_get_drvdata(pdev); 1031 struct ti_hecc_priv *priv = netdev_priv(dev); 1032 1033 clk_enable(priv->clk); 1034 1035 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1036 priv->can.state = CAN_STATE_ERROR_ACTIVE; 1037 1038 if (netif_running(dev)) { 1039 netif_device_attach(dev); 1040 netif_start_queue(dev); 1041 } 1042 1043 return 0; 1044 } 1045 #else 1046 #define ti_hecc_suspend NULL 1047 #define ti_hecc_resume NULL 1048 #endif 1049 1050 /* TI HECC netdevice driver: platform driver structure */ 1051 static struct platform_driver ti_hecc_driver = { 1052 .driver = { 1053 .name = DRV_NAME, 1054 .owner = THIS_MODULE, 1055 }, 1056 .probe = ti_hecc_probe, 1057 .remove = ti_hecc_remove, 1058 .suspend = ti_hecc_suspend, 1059 .resume = ti_hecc_resume, 1060 }; 1061 1062 module_platform_driver(ti_hecc_driver); 1063 1064 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); 1065 MODULE_LICENSE("GPL v2"); 1066 MODULE_DESCRIPTION(DRV_DESC); 1067 MODULE_ALIAS("platform:" DRV_NAME); 1068