1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI HECC (CAN) device driver 4 * 5 * This driver supports TI's HECC (High End CAN Controller module) and the 6 * specs for the same is available at <http://www.ti.com> 7 * 8 * Copyright (C) 2009 Texas Instruments Incorporated - http://www.ti.com/ 9 * Copyright (C) 2019 Jeroen Hofstee <jhofstee@victronenergy.com> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/kernel.h> 14 #include <linux/types.h> 15 #include <linux/interrupt.h> 16 #include <linux/errno.h> 17 #include <linux/ethtool.h> 18 #include <linux/netdevice.h> 19 #include <linux/skbuff.h> 20 #include <linux/platform_device.h> 21 #include <linux/clk.h> 22 #include <linux/io.h> 23 #include <linux/of.h> 24 #include <linux/of_device.h> 25 #include <linux/regulator/consumer.h> 26 27 #include <linux/can/dev.h> 28 #include <linux/can/error.h> 29 #include <linux/can/rx-offload.h> 30 31 #define DRV_NAME "ti_hecc" 32 #define HECC_MODULE_VERSION "0.7" 33 MODULE_VERSION(HECC_MODULE_VERSION); 34 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION 35 36 /* TX / RX Mailbox Configuration */ 37 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */ 38 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */ 39 40 /* Important Note: TX mailbox configuration 41 * TX mailboxes should be restricted to the number of SKB buffers to avoid 42 * maintaining SKB buffers separately. TX mailboxes should be a power of 2 43 * for the mailbox logic to work. Top mailbox numbers are reserved for RX 44 * and lower mailboxes for TX. 45 * 46 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT 47 * 4 (default) 2 48 * 8 3 49 * 16 4 50 */ 51 #define HECC_MB_TX_SHIFT 2 /* as per table above */ 52 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT) 53 54 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT) 55 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT) 56 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1) 57 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK) 58 59 /* RX mailbox configuration 60 * 61 * The remaining mailboxes are used for reception and are delivered 62 * based on their timestamp, to avoid a hardware race when CANME is 63 * changed while CAN-bus traffic is being received. 64 */ 65 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) 66 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) 67 #define HECC_RX_LAST_MBOX (HECC_MAX_TX_MBOX) 68 69 /* TI HECC module registers */ 70 #define HECC_CANME 0x0 /* Mailbox enable */ 71 #define HECC_CANMD 0x4 /* Mailbox direction */ 72 #define HECC_CANTRS 0x8 /* Transmit request set */ 73 #define HECC_CANTRR 0xC /* Transmit request */ 74 #define HECC_CANTA 0x10 /* Transmission acknowledge */ 75 #define HECC_CANAA 0x14 /* Abort acknowledge */ 76 #define HECC_CANRMP 0x18 /* Receive message pending */ 77 #define HECC_CANRML 0x1C /* Receive message lost */ 78 #define HECC_CANRFP 0x20 /* Remote frame pending */ 79 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */ 80 #define HECC_CANMC 0x28 /* Master control */ 81 #define HECC_CANBTC 0x2C /* Bit timing configuration */ 82 #define HECC_CANES 0x30 /* Error and status */ 83 #define HECC_CANTEC 0x34 /* Transmit error counter */ 84 #define HECC_CANREC 0x38 /* Receive error counter */ 85 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */ 86 #define HECC_CANGIM 0x40 /* Global interrupt mask */ 87 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */ 88 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */ 89 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */ 90 #define HECC_CANOPC 0x50 /* Overwrite protection control */ 91 #define HECC_CANTIOC 0x54 /* Transmit I/O control */ 92 #define HECC_CANRIOC 0x58 /* Receive I/O control */ 93 #define HECC_CANLNT 0x5C /* HECC only: Local network time */ 94 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */ 95 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */ 96 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */ 97 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */ 98 99 /* TI HECC RAM registers */ 100 #define HECC_CANMOTS 0x80 /* Message object time stamp */ 101 102 /* Mailbox registers */ 103 #define HECC_CANMID 0x0 104 #define HECC_CANMCF 0x4 105 #define HECC_CANMDL 0x8 106 #define HECC_CANMDH 0xC 107 108 #define HECC_SET_REG 0xFFFFFFFF 109 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */ 110 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */ 111 112 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */ 113 #define HECC_CANMC_CCR BIT(12) /* Change config request */ 114 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */ 115 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */ 116 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */ 117 #define HECC_CANMC_SRES BIT(5) /* Software reset */ 118 119 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */ 120 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */ 121 122 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */ 123 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */ 124 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */ 125 126 #define HECC_CANES_FE BIT(24) /* form error */ 127 #define HECC_CANES_BE BIT(23) /* bit error */ 128 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */ 129 #define HECC_CANES_CRCE BIT(21) /* CRC error */ 130 #define HECC_CANES_SE BIT(20) /* stuff bit error */ 131 #define HECC_CANES_ACKE BIT(19) /* ack error */ 132 #define HECC_CANES_BO BIT(18) /* Bus off status */ 133 #define HECC_CANES_EP BIT(17) /* Error passive status */ 134 #define HECC_CANES_EW BIT(16) /* Error warning status */ 135 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */ 136 #define HECC_CANES_CCE BIT(4) /* Change config enabled */ 137 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */ 138 139 #define HECC_CANBTC_SAM BIT(7) /* sample points */ 140 141 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\ 142 HECC_CANES_CRCE | HECC_CANES_SE |\ 143 HECC_CANES_ACKE) 144 #define HECC_CANES_FLAGS (HECC_BUS_ERROR | HECC_CANES_BO |\ 145 HECC_CANES_EP | HECC_CANES_EW) 146 147 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */ 148 149 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */ 150 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */ 151 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */ 152 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */ 153 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */ 154 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */ 155 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */ 156 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */ 157 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */ 158 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */ 159 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */ 160 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */ 161 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */ 162 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */ 163 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */ 164 165 /* CAN Bittiming constants as per HECC specs */ 166 static const struct can_bittiming_const ti_hecc_bittiming_const = { 167 .name = DRV_NAME, 168 .tseg1_min = 1, 169 .tseg1_max = 16, 170 .tseg2_min = 1, 171 .tseg2_max = 8, 172 .sjw_max = 4, 173 .brp_min = 1, 174 .brp_max = 256, 175 .brp_inc = 1, 176 }; 177 178 struct ti_hecc_priv { 179 struct can_priv can; /* MUST be first member/field */ 180 struct can_rx_offload offload; 181 struct net_device *ndev; 182 struct clk *clk; 183 void __iomem *base; 184 void __iomem *hecc_ram; 185 void __iomem *mbx; 186 bool use_hecc1int; 187 spinlock_t mbx_lock; /* CANME register needs protection */ 188 u32 tx_head; 189 u32 tx_tail; 190 struct regulator *reg_xceiver; 191 }; 192 193 static inline int get_tx_head_mb(struct ti_hecc_priv *priv) 194 { 195 return priv->tx_head & HECC_TX_MB_MASK; 196 } 197 198 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv) 199 { 200 return priv->tx_tail & HECC_TX_MB_MASK; 201 } 202 203 static inline int get_tx_head_prio(struct ti_hecc_priv *priv) 204 { 205 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO; 206 } 207 208 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val) 209 { 210 __raw_writel(val, priv->hecc_ram + mbxno * 4); 211 } 212 213 static inline u32 hecc_read_stamp(struct ti_hecc_priv *priv, u32 mbxno) 214 { 215 return __raw_readl(priv->hecc_ram + HECC_CANMOTS + mbxno * 4); 216 } 217 218 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, 219 u32 reg, u32 val) 220 { 221 __raw_writel(val, priv->mbx + mbxno * 0x10 + reg); 222 } 223 224 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) 225 { 226 return __raw_readl(priv->mbx + mbxno * 0x10 + reg); 227 } 228 229 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val) 230 { 231 __raw_writel(val, priv->base + reg); 232 } 233 234 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg) 235 { 236 return __raw_readl(priv->base + reg); 237 } 238 239 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg, 240 u32 bit_mask) 241 { 242 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask); 243 } 244 245 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg, 246 u32 bit_mask) 247 { 248 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask); 249 } 250 251 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask) 252 { 253 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0; 254 } 255 256 static int ti_hecc_set_btc(struct ti_hecc_priv *priv) 257 { 258 struct can_bittiming *bit_timing = &priv->can.bittiming; 259 u32 can_btc; 260 261 can_btc = (bit_timing->phase_seg2 - 1) & 0x7; 262 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1) 263 & 0xF) << 3; 264 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) { 265 if (bit_timing->brp > 4) 266 can_btc |= HECC_CANBTC_SAM; 267 else 268 netdev_warn(priv->ndev, 269 "WARN: Triple sampling not set due to h/w limitations"); 270 } 271 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8; 272 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16; 273 274 /* ERM being set to 0 by default meaning resync at falling edge */ 275 276 hecc_write(priv, HECC_CANBTC, can_btc); 277 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc); 278 279 return 0; 280 } 281 282 static int ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv, 283 int on) 284 { 285 if (!priv->reg_xceiver) 286 return 0; 287 288 if (on) 289 return regulator_enable(priv->reg_xceiver); 290 else 291 return regulator_disable(priv->reg_xceiver); 292 } 293 294 static void ti_hecc_reset(struct net_device *ndev) 295 { 296 u32 cnt; 297 struct ti_hecc_priv *priv = netdev_priv(ndev); 298 299 netdev_dbg(ndev, "resetting hecc ...\n"); 300 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES); 301 302 /* Set change control request and wait till enabled */ 303 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 304 305 /* INFO: It has been observed that at times CCE bit may not be 306 * set and hw seems to be ok even if this bit is not set so 307 * timing out with a timing of 1ms to respect the specs 308 */ 309 cnt = HECC_CCE_WAIT_COUNT; 310 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 311 --cnt; 312 udelay(10); 313 } 314 315 /* Note: On HECC, BTC can be programmed only in initialization mode, so 316 * it is expected that the can bittiming parameters are set via ip 317 * utility before the device is opened 318 */ 319 ti_hecc_set_btc(priv); 320 321 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */ 322 hecc_write(priv, HECC_CANMC, 0); 323 324 /* INFO: CAN net stack handles bus off and hence disabling auto-bus-on 325 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO); 326 */ 327 328 /* INFO: It has been observed that at times CCE bit may not be 329 * set and hw seems to be ok even if this bit is not set so 330 */ 331 cnt = HECC_CCE_WAIT_COUNT; 332 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 333 --cnt; 334 udelay(10); 335 } 336 337 /* Enable TX and RX I/O Control pins */ 338 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN); 339 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN); 340 341 /* Clear registers for clean operation */ 342 hecc_write(priv, HECC_CANTA, HECC_SET_REG); 343 hecc_write(priv, HECC_CANRMP, HECC_SET_REG); 344 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 345 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 346 hecc_write(priv, HECC_CANME, 0); 347 hecc_write(priv, HECC_CANMD, 0); 348 349 /* SCC compat mode NOT supported (and not needed too) */ 350 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM); 351 } 352 353 static void ti_hecc_start(struct net_device *ndev) 354 { 355 struct ti_hecc_priv *priv = netdev_priv(ndev); 356 u32 cnt, mbxno, mbx_mask; 357 358 /* put HECC in initialization mode and set btc */ 359 ti_hecc_reset(ndev); 360 361 priv->tx_head = HECC_TX_MASK; 362 priv->tx_tail = HECC_TX_MASK; 363 364 /* Enable local and global acceptance mask registers */ 365 hecc_write(priv, HECC_CANGAM, HECC_SET_REG); 366 367 /* Prepare configured mailboxes to receive messages */ 368 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) { 369 mbxno = HECC_MAX_MAILBOXES - 1 - cnt; 370 mbx_mask = BIT(mbxno); 371 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 372 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME); 373 hecc_write_lam(priv, mbxno, HECC_SET_REG); 374 hecc_set_bit(priv, HECC_CANMD, mbx_mask); 375 hecc_set_bit(priv, HECC_CANME, mbx_mask); 376 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 377 } 378 379 /* Enable tx interrupts */ 380 hecc_set_bit(priv, HECC_CANMIM, BIT(HECC_MAX_TX_MBOX) - 1); 381 382 /* Prevent message over-write to create a rx fifo, but not for 383 * the lowest priority mailbox, since that allows detecting 384 * overflows instead of the hardware silently dropping the 385 * messages. 386 */ 387 mbx_mask = ~BIT(HECC_RX_LAST_MBOX); 388 hecc_write(priv, HECC_CANOPC, mbx_mask); 389 390 /* Enable interrupts */ 391 if (priv->use_hecc1int) { 392 hecc_write(priv, HECC_CANMIL, HECC_SET_REG); 393 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK | 394 HECC_CANGIM_I1EN | HECC_CANGIM_SIL); 395 } else { 396 hecc_write(priv, HECC_CANMIL, 0); 397 hecc_write(priv, HECC_CANGIM, 398 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN); 399 } 400 priv->can.state = CAN_STATE_ERROR_ACTIVE; 401 } 402 403 static void ti_hecc_stop(struct net_device *ndev) 404 { 405 struct ti_hecc_priv *priv = netdev_priv(ndev); 406 407 /* Disable the CPK; stop sending, erroring and acking */ 408 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 409 410 /* Disable interrupts and disable mailboxes */ 411 hecc_write(priv, HECC_CANGIM, 0); 412 hecc_write(priv, HECC_CANMIM, 0); 413 hecc_write(priv, HECC_CANME, 0); 414 priv->can.state = CAN_STATE_STOPPED; 415 } 416 417 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode) 418 { 419 int ret = 0; 420 421 switch (mode) { 422 case CAN_MODE_START: 423 ti_hecc_start(ndev); 424 netif_wake_queue(ndev); 425 break; 426 default: 427 ret = -EOPNOTSUPP; 428 break; 429 } 430 431 return ret; 432 } 433 434 static int ti_hecc_get_berr_counter(const struct net_device *ndev, 435 struct can_berr_counter *bec) 436 { 437 struct ti_hecc_priv *priv = netdev_priv(ndev); 438 439 bec->txerr = hecc_read(priv, HECC_CANTEC); 440 bec->rxerr = hecc_read(priv, HECC_CANREC); 441 442 return 0; 443 } 444 445 /* ti_hecc_xmit: HECC Transmit 446 * 447 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the 448 * priority of the mailbox for transmission is dependent upon priority setting 449 * field in mailbox registers. The mailbox with highest value in priority field 450 * is transmitted first. Only when two mailboxes have the same value in 451 * priority field the highest numbered mailbox is transmitted first. 452 * 453 * To utilize the HECC priority feature as described above we start with the 454 * highest numbered mailbox with highest priority level and move on to the next 455 * mailbox with the same priority level and so on. Once we loop through all the 456 * transmit mailboxes we choose the next priority level (lower) and so on 457 * until we reach the lowest priority level on the lowest numbered mailbox 458 * when we stop transmission until all mailboxes are transmitted and then 459 * restart at highest numbered mailbox with highest priority. 460 * 461 * Two counters (head and tail) are used to track the next mailbox to transmit 462 * and to track the echo buffer for already transmitted mailbox. The queue 463 * is stopped when all the mailboxes are busy or when there is a priority 464 * value roll-over happens. 465 */ 466 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev) 467 { 468 struct ti_hecc_priv *priv = netdev_priv(ndev); 469 struct can_frame *cf = (struct can_frame *)skb->data; 470 u32 mbxno, mbx_mask, data; 471 unsigned long flags; 472 473 if (can_dev_dropped_skb(ndev, skb)) 474 return NETDEV_TX_OK; 475 476 mbxno = get_tx_head_mb(priv); 477 mbx_mask = BIT(mbxno); 478 spin_lock_irqsave(&priv->mbx_lock, flags); 479 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) { 480 spin_unlock_irqrestore(&priv->mbx_lock, flags); 481 netif_stop_queue(ndev); 482 netdev_err(priv->ndev, 483 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n", 484 priv->tx_head, priv->tx_tail); 485 return NETDEV_TX_BUSY; 486 } 487 spin_unlock_irqrestore(&priv->mbx_lock, flags); 488 489 /* Prepare mailbox for transmission */ 490 data = cf->len | (get_tx_head_prio(priv) << 8); 491 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ 492 data |= HECC_CANMCF_RTR; 493 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data); 494 495 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ 496 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE; 497 else /* Standard frame format */ 498 data = (cf->can_id & CAN_SFF_MASK) << 18; 499 hecc_write_mbx(priv, mbxno, HECC_CANMID, data); 500 hecc_write_mbx(priv, mbxno, HECC_CANMDL, 501 be32_to_cpu(*(__be32 *)(cf->data))); 502 if (cf->len > 4) 503 hecc_write_mbx(priv, mbxno, HECC_CANMDH, 504 be32_to_cpu(*(__be32 *)(cf->data + 4))); 505 else 506 *(u32 *)(cf->data + 4) = 0; 507 can_put_echo_skb(skb, ndev, mbxno, 0); 508 509 spin_lock_irqsave(&priv->mbx_lock, flags); 510 --priv->tx_head; 511 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) || 512 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) { 513 netif_stop_queue(ndev); 514 } 515 hecc_set_bit(priv, HECC_CANME, mbx_mask); 516 spin_unlock_irqrestore(&priv->mbx_lock, flags); 517 518 hecc_write(priv, HECC_CANTRS, mbx_mask); 519 520 return NETDEV_TX_OK; 521 } 522 523 static inline 524 struct ti_hecc_priv *rx_offload_to_priv(struct can_rx_offload *offload) 525 { 526 return container_of(offload, struct ti_hecc_priv, offload); 527 } 528 529 static struct sk_buff *ti_hecc_mailbox_read(struct can_rx_offload *offload, 530 unsigned int mbxno, u32 *timestamp, 531 bool drop) 532 { 533 struct ti_hecc_priv *priv = rx_offload_to_priv(offload); 534 struct sk_buff *skb; 535 struct can_frame *cf; 536 u32 data, mbx_mask; 537 538 mbx_mask = BIT(mbxno); 539 540 if (unlikely(drop)) { 541 skb = ERR_PTR(-ENOBUFS); 542 goto mark_as_read; 543 } 544 545 skb = alloc_can_skb(offload->dev, &cf); 546 if (unlikely(!skb)) { 547 skb = ERR_PTR(-ENOMEM); 548 goto mark_as_read; 549 } 550 551 data = hecc_read_mbx(priv, mbxno, HECC_CANMID); 552 if (data & HECC_CANMID_IDE) 553 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; 554 else 555 cf->can_id = (data >> 18) & CAN_SFF_MASK; 556 557 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF); 558 if (data & HECC_CANMCF_RTR) 559 cf->can_id |= CAN_RTR_FLAG; 560 cf->len = can_cc_dlc2len(data & 0xF); 561 562 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); 563 *(__be32 *)(cf->data) = cpu_to_be32(data); 564 if (cf->len > 4) { 565 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); 566 *(__be32 *)(cf->data + 4) = cpu_to_be32(data); 567 } 568 569 *timestamp = hecc_read_stamp(priv, mbxno); 570 571 /* Check for FIFO overrun. 572 * 573 * All but the last RX mailbox have activated overwrite 574 * protection. So skip check for overrun, if we're not 575 * handling the last RX mailbox. 576 * 577 * As the overwrite protection for the last RX mailbox is 578 * disabled, the CAN core might update while we're reading 579 * it. This means the skb might be inconsistent. 580 * 581 * Return an error to let rx-offload discard this CAN frame. 582 */ 583 if (unlikely(mbxno == HECC_RX_LAST_MBOX && 584 hecc_read(priv, HECC_CANRML) & mbx_mask)) 585 skb = ERR_PTR(-ENOBUFS); 586 587 mark_as_read: 588 hecc_write(priv, HECC_CANRMP, mbx_mask); 589 590 return skb; 591 } 592 593 static int ti_hecc_error(struct net_device *ndev, int int_status, 594 int err_status) 595 { 596 struct ti_hecc_priv *priv = netdev_priv(ndev); 597 struct can_frame *cf; 598 struct sk_buff *skb; 599 u32 timestamp; 600 int err; 601 602 if (err_status & HECC_BUS_ERROR) { 603 /* propagate the error condition to the can stack */ 604 skb = alloc_can_err_skb(ndev, &cf); 605 if (!skb) { 606 if (net_ratelimit()) 607 netdev_err(priv->ndev, 608 "%s: alloc_can_err_skb() failed\n", 609 __func__); 610 return -ENOMEM; 611 } 612 613 ++priv->can.can_stats.bus_error; 614 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; 615 if (err_status & HECC_CANES_FE) 616 cf->data[2] |= CAN_ERR_PROT_FORM; 617 if (err_status & HECC_CANES_BE) 618 cf->data[2] |= CAN_ERR_PROT_BIT; 619 if (err_status & HECC_CANES_SE) 620 cf->data[2] |= CAN_ERR_PROT_STUFF; 621 if (err_status & HECC_CANES_CRCE) 622 cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ; 623 if (err_status & HECC_CANES_ACKE) 624 cf->data[3] = CAN_ERR_PROT_LOC_ACK; 625 626 timestamp = hecc_read(priv, HECC_CANLNT); 627 err = can_rx_offload_queue_timestamp(&priv->offload, skb, 628 timestamp); 629 if (err) 630 ndev->stats.rx_fifo_errors++; 631 } 632 633 hecc_write(priv, HECC_CANES, HECC_CANES_FLAGS); 634 635 return 0; 636 } 637 638 static void ti_hecc_change_state(struct net_device *ndev, 639 enum can_state rx_state, 640 enum can_state tx_state) 641 { 642 struct ti_hecc_priv *priv = netdev_priv(ndev); 643 struct can_frame *cf; 644 struct sk_buff *skb; 645 u32 timestamp; 646 int err; 647 648 skb = alloc_can_err_skb(priv->ndev, &cf); 649 if (unlikely(!skb)) { 650 priv->can.state = max(tx_state, rx_state); 651 return; 652 } 653 654 can_change_state(priv->ndev, cf, tx_state, rx_state); 655 656 if (max(tx_state, rx_state) != CAN_STATE_BUS_OFF) { 657 cf->can_id |= CAN_ERR_CNT; 658 cf->data[6] = hecc_read(priv, HECC_CANTEC); 659 cf->data[7] = hecc_read(priv, HECC_CANREC); 660 } 661 662 timestamp = hecc_read(priv, HECC_CANLNT); 663 err = can_rx_offload_queue_timestamp(&priv->offload, skb, timestamp); 664 if (err) 665 ndev->stats.rx_fifo_errors++; 666 } 667 668 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id) 669 { 670 struct net_device *ndev = (struct net_device *)dev_id; 671 struct ti_hecc_priv *priv = netdev_priv(ndev); 672 struct net_device_stats *stats = &ndev->stats; 673 u32 mbxno, mbx_mask, int_status, err_status, stamp; 674 unsigned long flags, rx_pending; 675 u32 handled = 0; 676 677 int_status = hecc_read(priv, 678 priv->use_hecc1int ? 679 HECC_CANGIF1 : HECC_CANGIF0); 680 681 if (!int_status) 682 return IRQ_NONE; 683 684 err_status = hecc_read(priv, HECC_CANES); 685 if (unlikely(err_status & HECC_CANES_FLAGS)) 686 ti_hecc_error(ndev, int_status, err_status); 687 688 if (unlikely(int_status & HECC_CANGIM_DEF_MASK)) { 689 enum can_state rx_state, tx_state; 690 u32 rec = hecc_read(priv, HECC_CANREC); 691 u32 tec = hecc_read(priv, HECC_CANTEC); 692 693 if (int_status & HECC_CANGIF_WLIF) { 694 handled |= HECC_CANGIF_WLIF; 695 rx_state = rec >= tec ? CAN_STATE_ERROR_WARNING : 0; 696 tx_state = rec <= tec ? CAN_STATE_ERROR_WARNING : 0; 697 netdev_dbg(priv->ndev, "Error Warning interrupt\n"); 698 ti_hecc_change_state(ndev, rx_state, tx_state); 699 } 700 701 if (int_status & HECC_CANGIF_EPIF) { 702 handled |= HECC_CANGIF_EPIF; 703 rx_state = rec >= tec ? CAN_STATE_ERROR_PASSIVE : 0; 704 tx_state = rec <= tec ? CAN_STATE_ERROR_PASSIVE : 0; 705 netdev_dbg(priv->ndev, "Error passive interrupt\n"); 706 ti_hecc_change_state(ndev, rx_state, tx_state); 707 } 708 709 if (int_status & HECC_CANGIF_BOIF) { 710 handled |= HECC_CANGIF_BOIF; 711 rx_state = CAN_STATE_BUS_OFF; 712 tx_state = CAN_STATE_BUS_OFF; 713 netdev_dbg(priv->ndev, "Bus off interrupt\n"); 714 715 /* Disable all interrupts */ 716 hecc_write(priv, HECC_CANGIM, 0); 717 can_bus_off(ndev); 718 ti_hecc_change_state(ndev, rx_state, tx_state); 719 } 720 } else if (unlikely(priv->can.state != CAN_STATE_ERROR_ACTIVE)) { 721 enum can_state new_state, tx_state, rx_state; 722 u32 rec = hecc_read(priv, HECC_CANREC); 723 u32 tec = hecc_read(priv, HECC_CANTEC); 724 725 if (rec >= 128 || tec >= 128) 726 new_state = CAN_STATE_ERROR_PASSIVE; 727 else if (rec >= 96 || tec >= 96) 728 new_state = CAN_STATE_ERROR_WARNING; 729 else 730 new_state = CAN_STATE_ERROR_ACTIVE; 731 732 if (new_state < priv->can.state) { 733 rx_state = rec >= tec ? new_state : 0; 734 tx_state = rec <= tec ? new_state : 0; 735 ti_hecc_change_state(ndev, rx_state, tx_state); 736 } 737 } 738 739 if (int_status & HECC_CANGIF_GMIF) { 740 while (priv->tx_tail - priv->tx_head > 0) { 741 mbxno = get_tx_tail_mb(priv); 742 mbx_mask = BIT(mbxno); 743 if (!(mbx_mask & hecc_read(priv, HECC_CANTA))) 744 break; 745 hecc_write(priv, HECC_CANTA, mbx_mask); 746 spin_lock_irqsave(&priv->mbx_lock, flags); 747 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 748 spin_unlock_irqrestore(&priv->mbx_lock, flags); 749 stamp = hecc_read_stamp(priv, mbxno); 750 stats->tx_bytes += 751 can_rx_offload_get_echo_skb(&priv->offload, 752 mbxno, stamp, NULL); 753 stats->tx_packets++; 754 --priv->tx_tail; 755 } 756 757 /* restart queue if wrap-up or if queue stalled on last pkt */ 758 if ((priv->tx_head == priv->tx_tail && 759 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) || 760 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) && 761 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK))) 762 netif_wake_queue(ndev); 763 764 /* offload RX mailboxes and let NAPI deliver them */ 765 while ((rx_pending = hecc_read(priv, HECC_CANRMP))) { 766 can_rx_offload_irq_offload_timestamp(&priv->offload, 767 rx_pending); 768 } 769 } 770 771 /* clear all interrupt conditions - read back to avoid spurious ints */ 772 if (priv->use_hecc1int) { 773 hecc_write(priv, HECC_CANGIF1, handled); 774 int_status = hecc_read(priv, HECC_CANGIF1); 775 } else { 776 hecc_write(priv, HECC_CANGIF0, handled); 777 int_status = hecc_read(priv, HECC_CANGIF0); 778 } 779 780 can_rx_offload_irq_finish(&priv->offload); 781 782 return IRQ_HANDLED; 783 } 784 785 static int ti_hecc_open(struct net_device *ndev) 786 { 787 struct ti_hecc_priv *priv = netdev_priv(ndev); 788 int err; 789 790 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED, 791 ndev->name, ndev); 792 if (err) { 793 netdev_err(ndev, "error requesting interrupt\n"); 794 return err; 795 } 796 797 ti_hecc_transceiver_switch(priv, 1); 798 799 /* Open common can device */ 800 err = open_candev(ndev); 801 if (err) { 802 netdev_err(ndev, "open_candev() failed %d\n", err); 803 ti_hecc_transceiver_switch(priv, 0); 804 free_irq(ndev->irq, ndev); 805 return err; 806 } 807 808 ti_hecc_start(ndev); 809 can_rx_offload_enable(&priv->offload); 810 netif_start_queue(ndev); 811 812 return 0; 813 } 814 815 static int ti_hecc_close(struct net_device *ndev) 816 { 817 struct ti_hecc_priv *priv = netdev_priv(ndev); 818 819 netif_stop_queue(ndev); 820 can_rx_offload_disable(&priv->offload); 821 ti_hecc_stop(ndev); 822 free_irq(ndev->irq, ndev); 823 close_candev(ndev); 824 ti_hecc_transceiver_switch(priv, 0); 825 826 return 0; 827 } 828 829 static const struct net_device_ops ti_hecc_netdev_ops = { 830 .ndo_open = ti_hecc_open, 831 .ndo_stop = ti_hecc_close, 832 .ndo_start_xmit = ti_hecc_xmit, 833 .ndo_change_mtu = can_change_mtu, 834 }; 835 836 static const struct ethtool_ops ti_hecc_ethtool_ops = { 837 .get_ts_info = ethtool_op_get_ts_info, 838 }; 839 840 static const struct of_device_id ti_hecc_dt_ids[] = { 841 { 842 .compatible = "ti,am3517-hecc", 843 }, 844 { } 845 }; 846 MODULE_DEVICE_TABLE(of, ti_hecc_dt_ids); 847 848 static int ti_hecc_probe(struct platform_device *pdev) 849 { 850 struct net_device *ndev = (struct net_device *)0; 851 struct ti_hecc_priv *priv; 852 struct device_node *np = pdev->dev.of_node; 853 struct regulator *reg_xceiver; 854 int err = -ENODEV; 855 856 if (!IS_ENABLED(CONFIG_OF) || !np) 857 return -EINVAL; 858 859 reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver"); 860 if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER) 861 return -EPROBE_DEFER; 862 else if (IS_ERR(reg_xceiver)) 863 reg_xceiver = NULL; 864 865 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); 866 if (!ndev) { 867 dev_err(&pdev->dev, "alloc_candev failed\n"); 868 return -ENOMEM; 869 } 870 priv = netdev_priv(ndev); 871 872 /* handle hecc memory */ 873 priv->base = devm_platform_ioremap_resource_byname(pdev, "hecc"); 874 if (IS_ERR(priv->base)) { 875 dev_err(&pdev->dev, "hecc ioremap failed\n"); 876 err = PTR_ERR(priv->base); 877 goto probe_exit_candev; 878 } 879 880 /* handle hecc-ram memory */ 881 priv->hecc_ram = devm_platform_ioremap_resource_byname(pdev, 882 "hecc-ram"); 883 if (IS_ERR(priv->hecc_ram)) { 884 dev_err(&pdev->dev, "hecc-ram ioremap failed\n"); 885 err = PTR_ERR(priv->hecc_ram); 886 goto probe_exit_candev; 887 } 888 889 /* handle mbx memory */ 890 priv->mbx = devm_platform_ioremap_resource_byname(pdev, "mbx"); 891 if (IS_ERR(priv->mbx)) { 892 dev_err(&pdev->dev, "mbx ioremap failed\n"); 893 err = PTR_ERR(priv->mbx); 894 goto probe_exit_candev; 895 } 896 897 ndev->irq = platform_get_irq(pdev, 0); 898 if (ndev->irq < 0) { 899 err = ndev->irq; 900 goto probe_exit_candev; 901 } 902 903 priv->ndev = ndev; 904 priv->reg_xceiver = reg_xceiver; 905 priv->use_hecc1int = of_property_read_bool(np, "ti,use-hecc1int"); 906 907 priv->can.bittiming_const = &ti_hecc_bittiming_const; 908 priv->can.do_set_mode = ti_hecc_do_set_mode; 909 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter; 910 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 911 912 spin_lock_init(&priv->mbx_lock); 913 ndev->flags |= IFF_ECHO; 914 platform_set_drvdata(pdev, ndev); 915 SET_NETDEV_DEV(ndev, &pdev->dev); 916 ndev->netdev_ops = &ti_hecc_netdev_ops; 917 ndev->ethtool_ops = &ti_hecc_ethtool_ops; 918 919 priv->clk = clk_get(&pdev->dev, "hecc_ck"); 920 if (IS_ERR(priv->clk)) { 921 dev_err(&pdev->dev, "No clock available\n"); 922 err = PTR_ERR(priv->clk); 923 priv->clk = NULL; 924 goto probe_exit_candev; 925 } 926 priv->can.clock.freq = clk_get_rate(priv->clk); 927 928 err = clk_prepare_enable(priv->clk); 929 if (err) { 930 dev_err(&pdev->dev, "clk_prepare_enable() failed\n"); 931 goto probe_exit_release_clk; 932 } 933 934 priv->offload.mailbox_read = ti_hecc_mailbox_read; 935 priv->offload.mb_first = HECC_RX_FIRST_MBOX; 936 priv->offload.mb_last = HECC_RX_LAST_MBOX; 937 err = can_rx_offload_add_timestamp(ndev, &priv->offload); 938 if (err) { 939 dev_err(&pdev->dev, "can_rx_offload_add_timestamp() failed\n"); 940 goto probe_exit_disable_clk; 941 } 942 943 err = register_candev(ndev); 944 if (err) { 945 dev_err(&pdev->dev, "register_candev() failed\n"); 946 goto probe_exit_offload; 947 } 948 949 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", 950 priv->base, (u32)ndev->irq); 951 952 return 0; 953 954 probe_exit_offload: 955 can_rx_offload_del(&priv->offload); 956 probe_exit_disable_clk: 957 clk_disable_unprepare(priv->clk); 958 probe_exit_release_clk: 959 clk_put(priv->clk); 960 probe_exit_candev: 961 free_candev(ndev); 962 963 return err; 964 } 965 966 static int ti_hecc_remove(struct platform_device *pdev) 967 { 968 struct net_device *ndev = platform_get_drvdata(pdev); 969 struct ti_hecc_priv *priv = netdev_priv(ndev); 970 971 unregister_candev(ndev); 972 clk_disable_unprepare(priv->clk); 973 clk_put(priv->clk); 974 can_rx_offload_del(&priv->offload); 975 free_candev(ndev); 976 977 return 0; 978 } 979 980 #ifdef CONFIG_PM 981 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state) 982 { 983 struct net_device *dev = platform_get_drvdata(pdev); 984 struct ti_hecc_priv *priv = netdev_priv(dev); 985 986 if (netif_running(dev)) { 987 netif_stop_queue(dev); 988 netif_device_detach(dev); 989 } 990 991 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 992 priv->can.state = CAN_STATE_SLEEPING; 993 994 clk_disable_unprepare(priv->clk); 995 996 return 0; 997 } 998 999 static int ti_hecc_resume(struct platform_device *pdev) 1000 { 1001 struct net_device *dev = platform_get_drvdata(pdev); 1002 struct ti_hecc_priv *priv = netdev_priv(dev); 1003 int err; 1004 1005 err = clk_prepare_enable(priv->clk); 1006 if (err) 1007 return err; 1008 1009 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1010 priv->can.state = CAN_STATE_ERROR_ACTIVE; 1011 1012 if (netif_running(dev)) { 1013 netif_device_attach(dev); 1014 netif_start_queue(dev); 1015 } 1016 1017 return 0; 1018 } 1019 #else 1020 #define ti_hecc_suspend NULL 1021 #define ti_hecc_resume NULL 1022 #endif 1023 1024 /* TI HECC netdevice driver: platform driver structure */ 1025 static struct platform_driver ti_hecc_driver = { 1026 .driver = { 1027 .name = DRV_NAME, 1028 .of_match_table = ti_hecc_dt_ids, 1029 }, 1030 .probe = ti_hecc_probe, 1031 .remove = ti_hecc_remove, 1032 .suspend = ti_hecc_suspend, 1033 .resume = ti_hecc_resume, 1034 }; 1035 1036 module_platform_driver(ti_hecc_driver); 1037 1038 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); 1039 MODULE_LICENSE("GPL v2"); 1040 MODULE_DESCRIPTION(DRV_DESC); 1041 MODULE_ALIAS("platform:" DRV_NAME); 1042