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 * Copyright (C) 2019 Jeroen Hofstee <jhofstee@victronenergy.com> 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License as 12 * published by the Free Software Foundation version 2. 13 * 14 * This program is distributed as is WITHOUT ANY WARRANTY of any 15 * kind, whether express or implied; without even the implied warranty 16 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17 * GNU General Public License for more details. 18 * 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/types.h> 24 #include <linux/interrupt.h> 25 #include <linux/errno.h> 26 #include <linux/netdevice.h> 27 #include <linux/skbuff.h> 28 #include <linux/platform_device.h> 29 #include <linux/clk.h> 30 #include <linux/io.h> 31 #include <linux/of.h> 32 #include <linux/of_device.h> 33 #include <linux/regulator/consumer.h> 34 35 #include <linux/can/dev.h> 36 #include <linux/can/error.h> 37 #include <linux/can/led.h> 38 #include <linux/can/rx-offload.h> 39 40 #define DRV_NAME "ti_hecc" 41 #define HECC_MODULE_VERSION "0.7" 42 MODULE_VERSION(HECC_MODULE_VERSION); 43 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION 44 45 /* TX / RX Mailbox Configuration */ 46 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */ 47 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */ 48 49 /* Important Note: TX mailbox configuration 50 * TX mailboxes should be restricted to the number of SKB buffers to avoid 51 * maintaining SKB buffers separately. TX mailboxes should be a power of 2 52 * for the mailbox logic to work. Top mailbox numbers are reserved for RX 53 * and lower mailboxes for TX. 54 * 55 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT 56 * 4 (default) 2 57 * 8 3 58 * 16 4 59 */ 60 #define HECC_MB_TX_SHIFT 2 /* as per table above */ 61 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT) 62 63 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT) 64 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT) 65 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1) 66 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK) 67 68 /* RX mailbox configuration 69 * 70 * The remaining mailboxes are used for reception and are delivered 71 * based on their timestamp, to avoid a hardware race when CANME is 72 * changed while CAN-bus traffic is being received. 73 */ 74 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) 75 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) 76 #define HECC_RX_LAST_MBOX (HECC_MAX_TX_MBOX) 77 78 /* TI HECC module registers */ 79 #define HECC_CANME 0x0 /* Mailbox enable */ 80 #define HECC_CANMD 0x4 /* Mailbox direction */ 81 #define HECC_CANTRS 0x8 /* Transmit request set */ 82 #define HECC_CANTRR 0xC /* Transmit request */ 83 #define HECC_CANTA 0x10 /* Transmission acknowledge */ 84 #define HECC_CANAA 0x14 /* Abort acknowledge */ 85 #define HECC_CANRMP 0x18 /* Receive message pending */ 86 #define HECC_CANRML 0x1C /* Receive message lost */ 87 #define HECC_CANRFP 0x20 /* Remote frame pending */ 88 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */ 89 #define HECC_CANMC 0x28 /* Master control */ 90 #define HECC_CANBTC 0x2C /* Bit timing configuration */ 91 #define HECC_CANES 0x30 /* Error and status */ 92 #define HECC_CANTEC 0x34 /* Transmit error counter */ 93 #define HECC_CANREC 0x38 /* Receive error counter */ 94 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */ 95 #define HECC_CANGIM 0x40 /* Global interrupt mask */ 96 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */ 97 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */ 98 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */ 99 #define HECC_CANOPC 0x50 /* Overwrite protection control */ 100 #define HECC_CANTIOC 0x54 /* Transmit I/O control */ 101 #define HECC_CANRIOC 0x58 /* Receive I/O control */ 102 #define HECC_CANLNT 0x5C /* HECC only: Local network time */ 103 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */ 104 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */ 105 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */ 106 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */ 107 108 /* TI HECC RAM registers */ 109 #define HECC_CANMOTS 0x80 /* Message object time stamp */ 110 111 /* Mailbox registers */ 112 #define HECC_CANMID 0x0 113 #define HECC_CANMCF 0x4 114 #define HECC_CANMDL 0x8 115 #define HECC_CANMDH 0xC 116 117 #define HECC_SET_REG 0xFFFFFFFF 118 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */ 119 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */ 120 121 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */ 122 #define HECC_CANMC_CCR BIT(12) /* Change config request */ 123 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */ 124 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */ 125 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */ 126 #define HECC_CANMC_SRES BIT(5) /* Software reset */ 127 128 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */ 129 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */ 130 131 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */ 132 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */ 133 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */ 134 135 #define HECC_CANES_FE BIT(24) /* form error */ 136 #define HECC_CANES_BE BIT(23) /* bit error */ 137 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */ 138 #define HECC_CANES_CRCE BIT(21) /* CRC error */ 139 #define HECC_CANES_SE BIT(20) /* stuff bit error */ 140 #define HECC_CANES_ACKE BIT(19) /* ack error */ 141 #define HECC_CANES_BO BIT(18) /* Bus off status */ 142 #define HECC_CANES_EP BIT(17) /* Error passive status */ 143 #define HECC_CANES_EW BIT(16) /* Error warning status */ 144 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */ 145 #define HECC_CANES_CCE BIT(4) /* Change config enabled */ 146 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */ 147 148 #define HECC_CANBTC_SAM BIT(7) /* sample points */ 149 150 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\ 151 HECC_CANES_CRCE | HECC_CANES_SE |\ 152 HECC_CANES_ACKE) 153 #define HECC_CANES_FLAGS (HECC_BUS_ERROR | HECC_CANES_BO |\ 154 HECC_CANES_EP | HECC_CANES_EW) 155 156 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */ 157 158 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */ 159 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */ 160 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */ 161 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */ 162 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */ 163 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */ 164 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */ 165 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */ 166 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */ 167 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */ 168 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */ 169 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */ 170 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */ 171 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */ 172 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */ 173 174 /* CAN Bittiming constants as per HECC specs */ 175 static const struct can_bittiming_const ti_hecc_bittiming_const = { 176 .name = DRV_NAME, 177 .tseg1_min = 1, 178 .tseg1_max = 16, 179 .tseg2_min = 1, 180 .tseg2_max = 8, 181 .sjw_max = 4, 182 .brp_min = 1, 183 .brp_max = 256, 184 .brp_inc = 1, 185 }; 186 187 struct ti_hecc_priv { 188 struct can_priv can; /* MUST be first member/field */ 189 struct can_rx_offload offload; 190 struct net_device *ndev; 191 struct clk *clk; 192 void __iomem *base; 193 void __iomem *hecc_ram; 194 void __iomem *mbx; 195 bool use_hecc1int; 196 spinlock_t mbx_lock; /* CANME register needs protection */ 197 u32 tx_head; 198 u32 tx_tail; 199 struct regulator *reg_xceiver; 200 }; 201 202 static inline int get_tx_head_mb(struct ti_hecc_priv *priv) 203 { 204 return priv->tx_head & HECC_TX_MB_MASK; 205 } 206 207 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv) 208 { 209 return priv->tx_tail & HECC_TX_MB_MASK; 210 } 211 212 static inline int get_tx_head_prio(struct ti_hecc_priv *priv) 213 { 214 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO; 215 } 216 217 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val) 218 { 219 __raw_writel(val, priv->hecc_ram + mbxno * 4); 220 } 221 222 static inline u32 hecc_read_stamp(struct ti_hecc_priv *priv, u32 mbxno) 223 { 224 return __raw_readl(priv->hecc_ram + HECC_CANMOTS + mbxno * 4); 225 } 226 227 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, 228 u32 reg, u32 val) 229 { 230 __raw_writel(val, priv->mbx + mbxno * 0x10 + reg); 231 } 232 233 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) 234 { 235 return __raw_readl(priv->mbx + mbxno * 0x10 + reg); 236 } 237 238 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val) 239 { 240 __raw_writel(val, priv->base + reg); 241 } 242 243 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg) 244 { 245 return __raw_readl(priv->base + reg); 246 } 247 248 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg, 249 u32 bit_mask) 250 { 251 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask); 252 } 253 254 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg, 255 u32 bit_mask) 256 { 257 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask); 258 } 259 260 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask) 261 { 262 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0; 263 } 264 265 static int ti_hecc_set_btc(struct ti_hecc_priv *priv) 266 { 267 struct can_bittiming *bit_timing = &priv->can.bittiming; 268 u32 can_btc; 269 270 can_btc = (bit_timing->phase_seg2 - 1) & 0x7; 271 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1) 272 & 0xF) << 3; 273 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) { 274 if (bit_timing->brp > 4) 275 can_btc |= HECC_CANBTC_SAM; 276 else 277 netdev_warn(priv->ndev, 278 "WARN: Triple sampling not set due to h/w limitations"); 279 } 280 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8; 281 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16; 282 283 /* ERM being set to 0 by default meaning resync at falling edge */ 284 285 hecc_write(priv, HECC_CANBTC, can_btc); 286 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc); 287 288 return 0; 289 } 290 291 static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv, 292 int on) 293 { 294 if (!priv->reg_xceiver) 295 return 0; 296 297 if (on) 298 return regulator_enable(priv->reg_xceiver); 299 else 300 return regulator_disable(priv->reg_xceiver); 301 } 302 303 static void ti_hecc_reset(struct net_device *ndev) 304 { 305 u32 cnt; 306 struct ti_hecc_priv *priv = netdev_priv(ndev); 307 308 netdev_dbg(ndev, "resetting hecc ...\n"); 309 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES); 310 311 /* Set change control request and wait till enabled */ 312 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 313 314 /* INFO: It has been observed that at times CCE bit may not be 315 * set and hw seems to be ok even if this bit is not set so 316 * timing out with a timing of 1ms to respect the specs 317 */ 318 cnt = HECC_CCE_WAIT_COUNT; 319 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 320 --cnt; 321 udelay(10); 322 } 323 324 /* Note: On HECC, BTC can be programmed only in initialization mode, so 325 * it is expected that the can bittiming parameters are set via ip 326 * utility before the device is opened 327 */ 328 ti_hecc_set_btc(priv); 329 330 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */ 331 hecc_write(priv, HECC_CANMC, 0); 332 333 /* INFO: CAN net stack handles bus off and hence disabling auto-bus-on 334 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO); 335 */ 336 337 /* INFO: It has been observed that at times CCE bit may not be 338 * set and hw seems to be ok even if this bit is not set so 339 */ 340 cnt = HECC_CCE_WAIT_COUNT; 341 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 342 --cnt; 343 udelay(10); 344 } 345 346 /* Enable TX and RX I/O Control pins */ 347 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN); 348 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN); 349 350 /* Clear registers for clean operation */ 351 hecc_write(priv, HECC_CANTA, HECC_SET_REG); 352 hecc_write(priv, HECC_CANRMP, HECC_SET_REG); 353 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 354 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 355 hecc_write(priv, HECC_CANME, 0); 356 hecc_write(priv, HECC_CANMD, 0); 357 358 /* SCC compat mode NOT supported (and not needed too) */ 359 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM); 360 } 361 362 static void ti_hecc_start(struct net_device *ndev) 363 { 364 struct ti_hecc_priv *priv = netdev_priv(ndev); 365 u32 cnt, mbxno, mbx_mask; 366 367 /* put HECC in initialization mode and set btc */ 368 ti_hecc_reset(ndev); 369 370 priv->tx_head = HECC_TX_MASK; 371 priv->tx_tail = HECC_TX_MASK; 372 373 /* Enable local and global acceptance mask registers */ 374 hecc_write(priv, HECC_CANGAM, HECC_SET_REG); 375 376 /* Prepare configured mailboxes to receive messages */ 377 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) { 378 mbxno = HECC_MAX_MAILBOXES - 1 - cnt; 379 mbx_mask = BIT(mbxno); 380 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 381 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME); 382 hecc_write_lam(priv, mbxno, HECC_SET_REG); 383 hecc_set_bit(priv, HECC_CANMD, mbx_mask); 384 hecc_set_bit(priv, HECC_CANME, mbx_mask); 385 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 386 } 387 388 /* Enable tx interrupts */ 389 hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1); 390 391 /* Prevent message over-write to create a rx fifo, but not for 392 * the lowest priority mailbox, since that allows detecting 393 * overflows instead of the hardware silently dropping the 394 * messages. 395 */ 396 mbx_mask = ~BIT(HECC_RX_LAST_MBOX); 397 hecc_write(priv, HECC_CANOPC, mbx_mask); 398 399 /* Enable interrupts */ 400 if (priv->use_hecc1int) { 401 hecc_write(priv, HECC_CANMIL, HECC_SET_REG); 402 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK | 403 HECC_CANGIM_I1EN | HECC_CANGIM_SIL); 404 } else { 405 hecc_write(priv, HECC_CANMIL, 0); 406 hecc_write(priv, HECC_CANGIM, 407 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN); 408 } 409 priv->can.state = CAN_STATE_ERROR_ACTIVE; 410 } 411 412 static void ti_hecc_stop(struct net_device *ndev) 413 { 414 struct ti_hecc_priv *priv = netdev_priv(ndev); 415 416 /* Disable the CPK; stop sending, erroring and acking */ 417 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 418 419 /* Disable interrupts and disable mailboxes */ 420 hecc_write(priv, HECC_CANGIM, 0); 421 hecc_write(priv, HECC_CANMIM, 0); 422 hecc_write(priv, HECC_CANME, 0); 423 priv->can.state = CAN_STATE_STOPPED; 424 } 425 426 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode) 427 { 428 int ret = 0; 429 430 switch (mode) { 431 case CAN_MODE_START: 432 ti_hecc_start(ndev); 433 netif_wake_queue(ndev); 434 break; 435 default: 436 ret = -EOPNOTSUPP; 437 break; 438 } 439 440 return ret; 441 } 442 443 static int ti_hecc_get_berr_counter(const struct net_device *ndev, 444 struct can_berr_counter *bec) 445 { 446 struct ti_hecc_priv *priv = netdev_priv(ndev); 447 448 bec->txerr = hecc_read(priv, HECC_CANTEC); 449 bec->rxerr = hecc_read(priv, HECC_CANREC); 450 451 return 0; 452 } 453 454 /* ti_hecc_xmit: HECC Transmit 455 * 456 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the 457 * priority of the mailbox for transmission is dependent upon priority setting 458 * field in mailbox registers. The mailbox with highest value in priority field 459 * is transmitted first. Only when two mailboxes have the same value in 460 * priority field the highest numbered mailbox is transmitted first. 461 * 462 * To utilize the HECC priority feature as described above we start with the 463 * highest numbered mailbox with highest priority level and move on to the next 464 * mailbox with the same priority level and so on. Once we loop through all the 465 * transmit mailboxes we choose the next priority level (lower) and so on 466 * until we reach the lowest priority level on the lowest numbered mailbox 467 * when we stop transmission until all mailboxes are transmitted and then 468 * restart at highest numbered mailbox with highest priority. 469 * 470 * Two counters (head and tail) are used to track the next mailbox to transmit 471 * and to track the echo buffer for already transmitted mailbox. The queue 472 * is stopped when all the mailboxes are busy or when there is a priority 473 * value roll-over happens. 474 */ 475 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev) 476 { 477 struct ti_hecc_priv *priv = netdev_priv(ndev); 478 struct can_frame *cf = (struct can_frame *)skb->data; 479 u32 mbxno, mbx_mask, data; 480 unsigned long flags; 481 482 if (can_dropped_invalid_skb(ndev, skb)) 483 return NETDEV_TX_OK; 484 485 mbxno = get_tx_head_mb(priv); 486 mbx_mask = BIT(mbxno); 487 spin_lock_irqsave(&priv->mbx_lock, flags); 488 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) { 489 spin_unlock_irqrestore(&priv->mbx_lock, flags); 490 netif_stop_queue(ndev); 491 netdev_err(priv->ndev, 492 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n", 493 priv->tx_head, priv->tx_tail); 494 return NETDEV_TX_BUSY; 495 } 496 spin_unlock_irqrestore(&priv->mbx_lock, flags); 497 498 /* Prepare mailbox for transmission */ 499 data = cf->len | (get_tx_head_prio(priv) << 8); 500 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ 501 data |= HECC_CANMCF_RTR; 502 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data); 503 504 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ 505 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE; 506 else /* Standard frame format */ 507 data = (cf->can_id & CAN_SFF_MASK) << 18; 508 hecc_write_mbx(priv, mbxno, HECC_CANMID, data); 509 hecc_write_mbx(priv, mbxno, HECC_CANMDL, 510 be32_to_cpu(*(__be32 *)(cf->data))); 511 if (cf->len > 4) 512 hecc_write_mbx(priv, mbxno, HECC_CANMDH, 513 be32_to_cpu(*(__be32 *)(cf->data + 4))); 514 else 515 *(u32 *)(cf->data + 4) = 0; 516 can_put_echo_skb(skb, ndev, mbxno); 517 518 spin_lock_irqsave(&priv->mbx_lock, flags); 519 --priv->tx_head; 520 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) || 521 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) { 522 netif_stop_queue(ndev); 523 } 524 hecc_set_bit(priv, HECC_CANME, mbx_mask); 525 spin_unlock_irqrestore(&priv->mbx_lock, flags); 526 527 hecc_write(priv, HECC_CANTRS, mbx_mask); 528 529 return NETDEV_TX_OK; 530 } 531 532 static inline 533 struct ti_hecc_priv *rx_offload_to_priv(struct can_rx_offload *offload) 534 { 535 return container_of(offload, struct ti_hecc_priv, offload); 536 } 537 538 static struct sk_buff *ti_hecc_mailbox_read(struct can_rx_offload *offload, 539 unsigned int mbxno, u32 *timestamp, 540 bool drop) 541 { 542 struct ti_hecc_priv *priv = rx_offload_to_priv(offload); 543 struct sk_buff *skb; 544 struct can_frame *cf; 545 u32 data, mbx_mask; 546 547 mbx_mask = BIT(mbxno); 548 549 if (unlikely(drop)) { 550 skb = ERR_PTR(-ENOBUFS); 551 goto mark_as_read; 552 } 553 554 skb = alloc_can_skb(offload->dev, &cf); 555 if (unlikely(!skb)) { 556 skb = ERR_PTR(-ENOMEM); 557 goto mark_as_read; 558 } 559 560 data = hecc_read_mbx(priv, mbxno, HECC_CANMID); 561 if (data & HECC_CANMID_IDE) 562 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; 563 else 564 cf->can_id = (data >> 18) & CAN_SFF_MASK; 565 566 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF); 567 if (data & HECC_CANMCF_RTR) 568 cf->can_id |= CAN_RTR_FLAG; 569 cf->len = can_cc_dlc2len(data & 0xF); 570 571 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); 572 *(__be32 *)(cf->data) = cpu_to_be32(data); 573 if (cf->len > 4) { 574 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); 575 *(__be32 *)(cf->data + 4) = cpu_to_be32(data); 576 } 577 578 *timestamp = hecc_read_stamp(priv, mbxno); 579 580 /* Check for FIFO overrun. 581 * 582 * All but the last RX mailbox have activated overwrite 583 * protection. So skip check for overrun, if we're not 584 * handling the last RX mailbox. 585 * 586 * As the overwrite protection for the last RX mailbox is 587 * disabled, the CAN core might update while we're reading 588 * it. This means the skb might be inconsistent. 589 * 590 * Return an error to let rx-offload discard this CAN frame. 591 */ 592 if (unlikely(mbxno == HECC_RX_LAST_MBOX && 593 hecc_read(priv, HECC_CANRML) & mbx_mask)) 594 skb = ERR_PTR(-ENOBUFS); 595 596 mark_as_read: 597 hecc_write(priv, HECC_CANRMP, mbx_mask); 598 599 return skb; 600 } 601 602 static int ti_hecc_error(struct net_device *ndev, int int_status, 603 int err_status) 604 { 605 struct ti_hecc_priv *priv = netdev_priv(ndev); 606 struct can_frame *cf; 607 struct sk_buff *skb; 608 u32 timestamp; 609 int err; 610 611 if (err_status & HECC_BUS_ERROR) { 612 /* propagate the error condition to the can stack */ 613 skb = alloc_can_err_skb(ndev, &cf); 614 if (!skb) { 615 if (net_ratelimit()) 616 netdev_err(priv->ndev, 617 "%s: alloc_can_err_skb() failed\n", 618 __func__); 619 return -ENOMEM; 620 } 621 622 ++priv->can.can_stats.bus_error; 623 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; 624 if (err_status & HECC_CANES_FE) 625 cf->data[2] |= CAN_ERR_PROT_FORM; 626 if (err_status & HECC_CANES_BE) 627 cf->data[2] |= CAN_ERR_PROT_BIT; 628 if (err_status & HECC_CANES_SE) 629 cf->data[2] |= CAN_ERR_PROT_STUFF; 630 if (err_status & HECC_CANES_CRCE) 631 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; 632 if (err_status & HECC_CANES_ACKE) 633 cf->data[3] = CAN_ERR_PROT_LOC_ACK; 634 635 timestamp = hecc_read(priv, HECC_CANLNT); 636 err = can_rx_offload_queue_sorted(&priv->offload, skb, 637 timestamp); 638 if (err) 639 ndev->stats.rx_fifo_errors++; 640 } 641 642 hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS); 643 644 return 0; 645 } 646 647 static void ti_hecc_change_state(struct net_device *ndev, 648 enum can_state rx_state, 649 enum can_state tx_state) 650 { 651 struct ti_hecc_priv *priv = netdev_priv(ndev); 652 struct can_frame *cf; 653 struct sk_buff *skb; 654 u32 timestamp; 655 int err; 656 657 skb = alloc_can_err_skb(priv->ndev, &cf); 658 if (unlikely(!skb)) { 659 priv->can.state = max(tx_state, rx_state); 660 return; 661 } 662 663 can_change_state(priv->ndev, cf, tx_state, rx_state); 664 665 if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) { 666 cf->data[6] = hecc_read(priv, HECC_CANTEC); 667 cf->data[7] = hecc_read(priv, HECC_CANREC); 668 } 669 670 timestamp = hecc_read(priv, HECC_CANLNT); 671 err = can_rx_offload_queue_sorted(&priv->offload, skb, timestamp); 672 if (err) 673 ndev->stats.rx_fifo_errors++; 674 } 675 676 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id) 677 { 678 struct net_device *ndev = (struct net_device *)dev_id; 679 struct ti_hecc_priv *priv = netdev_priv(ndev); 680 struct net_device_stats *stats = &ndev->stats; 681 u32 mbxno, mbx_mask, int_status, err_status, stamp; 682 unsigned long flags, rx_pending; 683 u32 handled = 0; 684 685 int_status = hecc_read(priv, 686 priv->use_hecc1int ? 687 HECC_CANGIF1 : HECC_CANGIF0); 688 689 if (!int_status) 690 return IRQ_NONE; 691 692 err_status = hecc_read(priv, HECC_CANES); 693 if (unlikely(err_status & HECC_CANES_FLAGS)) 694 ti_hecc_error(ndev, int_status, err_status); 695 696 if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) { 697 enum can_state rx_state, tx_state; 698 u32 rec = hecc_read(priv, HECC_CANREC); 699 u32 tec = hecc_read(priv, HECC_CANTEC); 700 701 if (int_status & HECC_CANGIF_WLIF) { 702 handled |= HECC_CANGIF_WLIF; 703 rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0; 704 tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0; 705 netdev_dbg(priv->ndev, "Error Warning interrupt\n"); 706 ti_hecc_change_state(ndev, rx_state, tx_state); 707 } 708 709 if (int_status & HECC_CANGIF_EPIF) { 710 handled |= HECC_CANGIF_EPIF; 711 rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0; 712 tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0; 713 netdev_dbg(priv->ndev, "Error passive interrupt\n"); 714 ti_hecc_change_state(ndev, rx_state, tx_state); 715 } 716 717 if (int_status & HECC_CANGIF_BOIF) { 718 handled |= HECC_CANGIF_BOIF; 719 rx_state = CAN_STATE_BUS_OFF; 720 tx_state = CAN_STATE_BUS_OFF; 721 netdev_dbg(priv->ndev, "Bus off interrupt\n"); 722 723 /* Disable all interrupts */ 724 hecc_write(priv, HECC_CANGIM, 0); 725 can_bus_off(ndev); 726 ti_hecc_change_state(ndev, rx_state, tx_state); 727 } 728 } else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) { 729 enum can_state new_state, tx_state, rx_state; 730 u32 rec = hecc_read(priv, HECC_CANREC); 731 u32 tec = hecc_read(priv, HECC_CANTEC); 732 733 if (rec >= 128 || tec >= 128) 734 new_state = CAN_STATE_ERROR_PASSIVE; 735 else if (rec >= 96 || tec >= 96) 736 new_state = CAN_STATE_ERROR_WARNING; 737 else 738 new_state = CAN_STATE_ERROR_ACTIVE; 739 740 if (new_state < priv->can.state) { 741 rx_state = rec >= tec ? new_state : 0; 742 tx_state = rec <= tec ? new_state : 0; 743 ti_hecc_change_state(ndev, rx_state, tx_state); 744 } 745 } 746 747 if (int_status & HECC_CANGIF_GMIF) { 748 while (priv->tx_tail - priv->tx_head > 0) { 749 mbxno = get_tx_tail_mb(priv); 750 mbx_mask = BIT(mbxno); 751 if (!(mbx_mask & hecc_read(priv, HECC_CANTA))) 752 break; 753 hecc_write(priv, HECC_CANTA, mbx_mask); 754 spin_lock_irqsave(&priv->mbx_lock, flags); 755 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 756 spin_unlock_irqrestore(&priv->mbx_lock, flags); 757 stamp = hecc_read_stamp(priv, mbxno); 758 stats->tx_bytes += 759 can_rx_offload_get_echo_skb(&priv->offload, 760 mbxno, stamp); 761 stats->tx_packets++; 762 can_led_event(ndev, CAN_LED_EVENT_TX); 763 --priv->tx_tail; 764 } 765 766 /* restart queue if wrap-up or if queue stalled on last pkt */ 767 if ((priv->tx_head == priv->tx_tail && 768 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) || 769 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) && 770 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK))) 771 netif_wake_queue(ndev); 772 773 /* offload RX mailboxes and let NAPI deliver them */ 774 while ((rx_pending = hecc_read(priv, HECC_CANRMP))) { 775 can_rx_offload_irq_offload_timestamp(&priv->offload, 776 rx_pending); 777 } 778 } 779 780 /* clear all interrupt conditions - read back to avoid spurious ints */ 781 if (priv->use_hecc1int) { 782 hecc_write(priv, HECC_CANGIF1, handled); 783 int_status = hecc_read(priv, HECC_CANGIF1); 784 } else { 785 hecc_write(priv, HECC_CANGIF0, handled); 786 int_status = hecc_read(priv, HECC_CANGIF0); 787 } 788 789 return IRQ_HANDLED; 790 } 791 792 static int ti_hecc_open(struct net_device *ndev) 793 { 794 struct ti_hecc_priv *priv = netdev_priv(ndev); 795 int err; 796 797 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED, 798 ndev->name, ndev); 799 if (err) { 800 netdev_err(ndev, "error requesting interrupt\n"); 801 return err; 802 } 803 804 ti_hecc_transceiver_switch(priv, 1); 805 806 /* Open common can device */ 807 err = open_candev(ndev); 808 if (err) { 809 netdev_err(ndev, "open_candev() failed %d\n", err); 810 ti_hecc_transceiver_switch(priv, 0); 811 free_irq(ndev->irq, ndev); 812 return err; 813 } 814 815 can_led_event(ndev, CAN_LED_EVENT_OPEN); 816 817 ti_hecc_start(ndev); 818 can_rx_offload_enable(&priv->offload); 819 netif_start_queue(ndev); 820 821 return 0; 822 } 823 824 static int ti_hecc_close(struct net_device *ndev) 825 { 826 struct ti_hecc_priv *priv = netdev_priv(ndev); 827 828 netif_stop_queue(ndev); 829 can_rx_offload_disable(&priv->offload); 830 ti_hecc_stop(ndev); 831 free_irq(ndev->irq, ndev); 832 close_candev(ndev); 833 ti_hecc_transceiver_switch(priv, 0); 834 835 can_led_event(ndev, CAN_LED_EVENT_STOP); 836 837 return 0; 838 } 839 840 static const struct net_device_ops ti_hecc_netdev_ops = { 841 .ndo_open = ti_hecc_open, 842 .ndo_stop = ti_hecc_close, 843 .ndo_start_xmit = ti_hecc_xmit, 844 .ndo_change_mtu = can_change_mtu, 845 }; 846 847 static const struct of_device_id ti_hecc_dt_ids[] = { 848 { 849 .compatible = "ti,am3517-hecc", 850 }, 851 { } 852 }; 853 MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids); 854 855 static int ti_hecc_probe(struct platform_device *pdev) 856 { 857 struct net_device *ndev = (struct net_device *)0; 858 struct ti_hecc_priv *priv; 859 struct device_node *np = pdev->dev.of_node; 860 struct resource *irq; 861 struct regulator *reg_xceiver; 862 int err = -ENODEV; 863 864 if (!IS_ENABLED(CONFIG_OF) || !np) 865 return -EINVAL; 866 867 reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver"); 868 if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER) 869 return -EPROBE_DEFER; 870 else if (IS_ERR(reg_xceiver)) 871 reg_xceiver = NULL; 872 873 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); 874 if (!ndev) { 875 dev_err(&pdev->dev, "alloc_candev failed\n"); 876 return -ENOMEM; 877 } 878 priv = netdev_priv(ndev); 879 880 /* handle hecc memory */ 881 priv->base = devm_platform_ioremap_resource_byname(pdev, "hecc"); 882 if (IS_ERR(priv->base)) { 883 dev_err(&pdev->dev, "hecc ioremap failed\n"); 884 err = PTR_ERR(priv->base); 885 goto probe_exit_candev; 886 } 887 888 /* handle hecc-ram memory */ 889 priv->hecc_ram = devm_platform_ioremap_resource_byname(pdev, 890 "hecc-ram"); 891 if (IS_ERR(priv->hecc_ram)) { 892 dev_err(&pdev->dev, "hecc-ram ioremap failed\n"); 893 err = PTR_ERR(priv->hecc_ram); 894 goto probe_exit_candev; 895 } 896 897 /* handle mbx memory */ 898 priv->mbx = devm_platform_ioremap_resource_byname(pdev, "mbx"); 899 if (IS_ERR(priv->mbx)) { 900 dev_err(&pdev->dev, "mbx ioremap failed\n"); 901 err = PTR_ERR(priv->mbx); 902 goto probe_exit_candev; 903 } 904 905 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 906 if (!irq) { 907 dev_err(&pdev->dev, "No irq resource\n"); 908 goto probe_exit_candev; 909 } 910 911 priv->ndev = ndev; 912 priv->reg_xceiver = reg_xceiver; 913 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int"); 914 915 priv->can.bittiming_const = &ti_hecc_bittiming_const; 916 priv->can.do_set_mode = ti_hecc_do_set_mode; 917 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter; 918 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 919 920 spin_lock_init(&priv->mbx_lock); 921 ndev->irq = irq->start; 922 ndev->flags |= IFF_ECHO; 923 platform_set_drvdata(pdev, ndev); 924 SET_NETDEV_DEV(ndev, &pdev->dev); 925 ndev->netdev_ops = &ti_hecc_netdev_ops; 926 927 priv->clk = clk_get(&pdev->dev, "hecc_ck"); 928 if (IS_ERR(priv->clk)) { 929 dev_err(&pdev->dev, "No clock available\n"); 930 err = PTR_ERR(priv->clk); 931 priv->clk = NULL; 932 goto probe_exit_candev; 933 } 934 priv->can.clock.freq = clk_get_rate(priv->clk); 935 936 err = clk_prepare_enable(priv->clk); 937 if (err) { 938 dev_err(&pdev->dev, "clk_prepare_enable() failed\n"); 939 goto probe_exit_release_clk; 940 } 941 942 priv->offload.mailbox_read = ti_hecc_mailbox_read; 943 priv->offload.mb_first = HECC_RX_FIRST_MBOX; 944 priv->offload.mb_last = HECC_RX_LAST_MBOX; 945 err = can_rx_offload_add_timestamp(ndev, &priv->offload); 946 if (err) { 947 dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n"); 948 goto probe_exit_disable_clk; 949 } 950 951 err = register_candev(ndev); 952 if (err) { 953 dev_err(&pdev->dev, "register_candev() failed\n"); 954 goto probe_exit_offload; 955 } 956 957 devm_can_led_init(ndev); 958 959 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", 960 priv->base, (u32)ndev->irq); 961 962 return 0; 963 964 probe_exit_offload: 965 can_rx_offload_del(&priv->offload); 966 probe_exit_disable_clk: 967 clk_disable_unprepare(priv->clk); 968 probe_exit_release_clk: 969 clk_put(priv->clk); 970 probe_exit_candev: 971 free_candev(ndev); 972 973 return err; 974 } 975 976 static int ti_hecc_remove(struct platform_device *pdev) 977 { 978 struct net_device *ndev = platform_get_drvdata(pdev); 979 struct ti_hecc_priv *priv = netdev_priv(ndev); 980 981 unregister_candev(ndev); 982 clk_disable_unprepare(priv->clk); 983 clk_put(priv->clk); 984 can_rx_offload_del(&priv->offload); 985 free_candev(ndev); 986 987 return 0; 988 } 989 990 #ifdef CONFIG_PM 991 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state) 992 { 993 struct net_device *dev = platform_get_drvdata(pdev); 994 struct ti_hecc_priv *priv = netdev_priv(dev); 995 996 if (netif_running(dev)) { 997 netif_stop_queue(dev); 998 netif_device_detach(dev); 999 } 1000 1001 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1002 priv->can.state = CAN_STATE_SLEEPING; 1003 1004 clk_disable_unprepare(priv->clk); 1005 1006 return 0; 1007 } 1008 1009 static int ti_hecc_resume(struct platform_device *pdev) 1010 { 1011 struct net_device *dev = platform_get_drvdata(pdev); 1012 struct ti_hecc_priv *priv = netdev_priv(dev); 1013 int err; 1014 1015 err = clk_prepare_enable(priv->clk); 1016 if (err) 1017 return err; 1018 1019 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1020 priv->can.state = CAN_STATE_ERROR_ACTIVE; 1021 1022 if (netif_running(dev)) { 1023 netif_device_attach(dev); 1024 netif_start_queue(dev); 1025 } 1026 1027 return 0; 1028 } 1029 #else 1030 #define ti_hecc_suspend NULL 1031 #define ti_hecc_resume NULL 1032 #endif 1033 1034 /* TI HECC netdevice driver: platform driver structure */ 1035 static struct platform_driver ti_hecc_driver = { 1036 .driver = { 1037 .name = DRV_NAME, 1038 .of_match_table = ti_hecc_dt_ids, 1039 }, 1040 .probe = ti_hecc_probe, 1041 .remove = ti_hecc_remove, 1042 .suspend = ti_hecc_suspend, 1043 .resume = ti_hecc_resume, 1044 }; 1045 1046 module_platform_driver(ti_hecc_driver); 1047 1048 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); 1049 MODULE_LICENSE("GPL v2"); 1050 MODULE_DESCRIPTION(DRV_DESC); 1051 MODULE_ALIAS("platform:" DRV_NAME); 1052