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/kernel.h> 41 #include <linux/types.h> 42 #include <linux/interrupt.h> 43 #include <linux/errno.h> 44 #include <linux/netdevice.h> 45 #include <linux/skbuff.h> 46 #include <linux/platform_device.h> 47 #include <linux/clk.h> 48 #include <linux/io.h> 49 50 #include <linux/can/dev.h> 51 #include <linux/can/error.h> 52 #include <linux/can/led.h> 53 #include <linux/can/platform/ti_hecc.h> 54 55 #define DRV_NAME "ti_hecc" 56 #define HECC_MODULE_VERSION "0.7" 57 MODULE_VERSION(HECC_MODULE_VERSION); 58 #define DRV_DESC "TI High End CAN Controller Driver " HECC_MODULE_VERSION 59 60 /* TX / RX Mailbox Configuration */ 61 #define HECC_MAX_MAILBOXES 32 /* hardware mailboxes - do not change */ 62 #define MAX_TX_PRIO 0x3F /* hardware value - do not change */ 63 64 /* 65 * Important Note: TX mailbox configuration 66 * TX mailboxes should be restricted to the number of SKB buffers to avoid 67 * maintaining SKB buffers separately. TX mailboxes should be a power of 2 68 * for the mailbox logic to work. Top mailbox numbers are reserved for RX 69 * and lower mailboxes for TX. 70 * 71 * HECC_MAX_TX_MBOX HECC_MB_TX_SHIFT 72 * 4 (default) 2 73 * 8 3 74 * 16 4 75 */ 76 #define HECC_MB_TX_SHIFT 2 /* as per table above */ 77 #define HECC_MAX_TX_MBOX BIT(HECC_MB_TX_SHIFT) 78 79 #define HECC_TX_PRIO_SHIFT (HECC_MB_TX_SHIFT) 80 #define HECC_TX_PRIO_MASK (MAX_TX_PRIO << HECC_MB_TX_SHIFT) 81 #define HECC_TX_MB_MASK (HECC_MAX_TX_MBOX - 1) 82 #define HECC_TX_MASK ((HECC_MAX_TX_MBOX - 1) | HECC_TX_PRIO_MASK) 83 #define HECC_TX_MBOX_MASK (~(BIT(HECC_MAX_TX_MBOX) - 1)) 84 #define HECC_DEF_NAPI_WEIGHT HECC_MAX_RX_MBOX 85 86 /* 87 * Important Note: RX mailbox configuration 88 * RX mailboxes are further logically split into two - main and buffer 89 * mailboxes. The goal is to get all packets into main mailboxes as 90 * driven by mailbox number and receive priority (higher to lower) and 91 * buffer mailboxes are used to receive pkts while main mailboxes are being 92 * processed. This ensures in-order packet reception. 93 * 94 * Here are the recommended values for buffer mailbox. Note that RX mailboxes 95 * start after TX mailboxes: 96 * 97 * HECC_MAX_RX_MBOX HECC_RX_BUFFER_MBOX No of buffer mailboxes 98 * 28 12 8 99 * 16 20 4 100 */ 101 102 #define HECC_MAX_RX_MBOX (HECC_MAX_MAILBOXES - HECC_MAX_TX_MBOX) 103 #define HECC_RX_BUFFER_MBOX 12 /* as per table above */ 104 #define HECC_RX_FIRST_MBOX (HECC_MAX_MAILBOXES - 1) 105 #define HECC_RX_HIGH_MBOX_MASK (~(BIT(HECC_RX_BUFFER_MBOX) - 1)) 106 107 /* TI HECC module registers */ 108 #define HECC_CANME 0x0 /* Mailbox enable */ 109 #define HECC_CANMD 0x4 /* Mailbox direction */ 110 #define HECC_CANTRS 0x8 /* Transmit request set */ 111 #define HECC_CANTRR 0xC /* Transmit request */ 112 #define HECC_CANTA 0x10 /* Transmission acknowledge */ 113 #define HECC_CANAA 0x14 /* Abort acknowledge */ 114 #define HECC_CANRMP 0x18 /* Receive message pending */ 115 #define HECC_CANRML 0x1C /* Remote message lost */ 116 #define HECC_CANRFP 0x20 /* Remote frame pending */ 117 #define HECC_CANGAM 0x24 /* SECC only:Global acceptance mask */ 118 #define HECC_CANMC 0x28 /* Master control */ 119 #define HECC_CANBTC 0x2C /* Bit timing configuration */ 120 #define HECC_CANES 0x30 /* Error and status */ 121 #define HECC_CANTEC 0x34 /* Transmit error counter */ 122 #define HECC_CANREC 0x38 /* Receive error counter */ 123 #define HECC_CANGIF0 0x3C /* Global interrupt flag 0 */ 124 #define HECC_CANGIM 0x40 /* Global interrupt mask */ 125 #define HECC_CANGIF1 0x44 /* Global interrupt flag 1 */ 126 #define HECC_CANMIM 0x48 /* Mailbox interrupt mask */ 127 #define HECC_CANMIL 0x4C /* Mailbox interrupt level */ 128 #define HECC_CANOPC 0x50 /* Overwrite protection control */ 129 #define HECC_CANTIOC 0x54 /* Transmit I/O control */ 130 #define HECC_CANRIOC 0x58 /* Receive I/O control */ 131 #define HECC_CANLNT 0x5C /* HECC only: Local network time */ 132 #define HECC_CANTOC 0x60 /* HECC only: Time-out control */ 133 #define HECC_CANTOS 0x64 /* HECC only: Time-out status */ 134 #define HECC_CANTIOCE 0x68 /* SCC only:Enhanced TX I/O control */ 135 #define HECC_CANRIOCE 0x6C /* SCC only:Enhanced RX I/O control */ 136 137 /* Mailbox registers */ 138 #define HECC_CANMID 0x0 139 #define HECC_CANMCF 0x4 140 #define HECC_CANMDL 0x8 141 #define HECC_CANMDH 0xC 142 143 #define HECC_SET_REG 0xFFFFFFFF 144 #define HECC_CANID_MASK 0x3FF /* 18 bits mask for extended id's */ 145 #define HECC_CCE_WAIT_COUNT 100 /* Wait for ~1 sec for CCE bit */ 146 147 #define HECC_CANMC_SCM BIT(13) /* SCC compat mode */ 148 #define HECC_CANMC_CCR BIT(12) /* Change config request */ 149 #define HECC_CANMC_PDR BIT(11) /* Local Power down - for sleep mode */ 150 #define HECC_CANMC_ABO BIT(7) /* Auto Bus On */ 151 #define HECC_CANMC_STM BIT(6) /* Self test mode - loopback */ 152 #define HECC_CANMC_SRES BIT(5) /* Software reset */ 153 154 #define HECC_CANTIOC_EN BIT(3) /* Enable CAN TX I/O pin */ 155 #define HECC_CANRIOC_EN BIT(3) /* Enable CAN RX I/O pin */ 156 157 #define HECC_CANMID_IDE BIT(31) /* Extended frame format */ 158 #define HECC_CANMID_AME BIT(30) /* Acceptance mask enable */ 159 #define HECC_CANMID_AAM BIT(29) /* Auto answer mode */ 160 161 #define HECC_CANES_FE BIT(24) /* form error */ 162 #define HECC_CANES_BE BIT(23) /* bit error */ 163 #define HECC_CANES_SA1 BIT(22) /* stuck at dominant error */ 164 #define HECC_CANES_CRCE BIT(21) /* CRC error */ 165 #define HECC_CANES_SE BIT(20) /* stuff bit error */ 166 #define HECC_CANES_ACKE BIT(19) /* ack error */ 167 #define HECC_CANES_BO BIT(18) /* Bus off status */ 168 #define HECC_CANES_EP BIT(17) /* Error passive status */ 169 #define HECC_CANES_EW BIT(16) /* Error warning status */ 170 #define HECC_CANES_SMA BIT(5) /* suspend mode ack */ 171 #define HECC_CANES_CCE BIT(4) /* Change config enabled */ 172 #define HECC_CANES_PDA BIT(3) /* Power down mode ack */ 173 174 #define HECC_CANBTC_SAM BIT(7) /* sample points */ 175 176 #define HECC_BUS_ERROR (HECC_CANES_FE | HECC_CANES_BE |\ 177 HECC_CANES_CRCE | HECC_CANES_SE |\ 178 HECC_CANES_ACKE) 179 180 #define HECC_CANMCF_RTR BIT(4) /* Remote transmit request */ 181 182 #define HECC_CANGIF_MAIF BIT(17) /* Message alarm interrupt */ 183 #define HECC_CANGIF_TCOIF BIT(16) /* Timer counter overflow int */ 184 #define HECC_CANGIF_GMIF BIT(15) /* Global mailbox interrupt */ 185 #define HECC_CANGIF_AAIF BIT(14) /* Abort ack interrupt */ 186 #define HECC_CANGIF_WDIF BIT(13) /* Write denied interrupt */ 187 #define HECC_CANGIF_WUIF BIT(12) /* Wake up interrupt */ 188 #define HECC_CANGIF_RMLIF BIT(11) /* Receive message lost interrupt */ 189 #define HECC_CANGIF_BOIF BIT(10) /* Bus off interrupt */ 190 #define HECC_CANGIF_EPIF BIT(9) /* Error passive interrupt */ 191 #define HECC_CANGIF_WLIF BIT(8) /* Warning level interrupt */ 192 #define HECC_CANGIF_MBOX_MASK 0x1F /* Mailbox number mask */ 193 #define HECC_CANGIM_I1EN BIT(1) /* Int line 1 enable */ 194 #define HECC_CANGIM_I0EN BIT(0) /* Int line 0 enable */ 195 #define HECC_CANGIM_DEF_MASK 0x700 /* only busoff/warning/passive */ 196 #define HECC_CANGIM_SIL BIT(2) /* system interrupts to int line 1 */ 197 198 /* CAN Bittiming constants as per HECC specs */ 199 static const struct can_bittiming_const ti_hecc_bittiming_const = { 200 .name = DRV_NAME, 201 .tseg1_min = 1, 202 .tseg1_max = 16, 203 .tseg2_min = 1, 204 .tseg2_max = 8, 205 .sjw_max = 4, 206 .brp_min = 1, 207 .brp_max = 256, 208 .brp_inc = 1, 209 }; 210 211 struct ti_hecc_priv { 212 struct can_priv can; /* MUST be first member/field */ 213 struct napi_struct napi; 214 struct net_device *ndev; 215 struct clk *clk; 216 void __iomem *base; 217 u32 scc_ram_offset; 218 u32 hecc_ram_offset; 219 u32 mbx_offset; 220 u32 int_line; 221 spinlock_t mbx_lock; /* CANME register needs protection */ 222 u32 tx_head; 223 u32 tx_tail; 224 u32 rx_next; 225 void (*transceiver_switch)(int); 226 }; 227 228 static inline int get_tx_head_mb(struct ti_hecc_priv *priv) 229 { 230 return priv->tx_head & HECC_TX_MB_MASK; 231 } 232 233 static inline int get_tx_tail_mb(struct ti_hecc_priv *priv) 234 { 235 return priv->tx_tail & HECC_TX_MB_MASK; 236 } 237 238 static inline int get_tx_head_prio(struct ti_hecc_priv *priv) 239 { 240 return (priv->tx_head >> HECC_TX_PRIO_SHIFT) & MAX_TX_PRIO; 241 } 242 243 static inline void hecc_write_lam(struct ti_hecc_priv *priv, u32 mbxno, u32 val) 244 { 245 __raw_writel(val, priv->base + priv->hecc_ram_offset + mbxno * 4); 246 } 247 248 static inline void hecc_write_mbx(struct ti_hecc_priv *priv, u32 mbxno, 249 u32 reg, u32 val) 250 { 251 __raw_writel(val, priv->base + priv->mbx_offset + mbxno * 0x10 + 252 reg); 253 } 254 255 static inline u32 hecc_read_mbx(struct ti_hecc_priv *priv, u32 mbxno, u32 reg) 256 { 257 return __raw_readl(priv->base + priv->mbx_offset + mbxno * 0x10 + 258 reg); 259 } 260 261 static inline void hecc_write(struct ti_hecc_priv *priv, u32 reg, u32 val) 262 { 263 __raw_writel(val, priv->base + reg); 264 } 265 266 static inline u32 hecc_read(struct ti_hecc_priv *priv, int reg) 267 { 268 return __raw_readl(priv->base + reg); 269 } 270 271 static inline void hecc_set_bit(struct ti_hecc_priv *priv, int reg, 272 u32 bit_mask) 273 { 274 hecc_write(priv, reg, hecc_read(priv, reg) | bit_mask); 275 } 276 277 static inline void hecc_clear_bit(struct ti_hecc_priv *priv, int reg, 278 u32 bit_mask) 279 { 280 hecc_write(priv, reg, hecc_read(priv, reg) & ~bit_mask); 281 } 282 283 static inline u32 hecc_get_bit(struct ti_hecc_priv *priv, int reg, u32 bit_mask) 284 { 285 return (hecc_read(priv, reg) & bit_mask) ? 1 : 0; 286 } 287 288 static int ti_hecc_set_btc(struct ti_hecc_priv *priv) 289 { 290 struct can_bittiming *bit_timing = &priv->can.bittiming; 291 u32 can_btc; 292 293 can_btc = (bit_timing->phase_seg2 - 1) & 0x7; 294 can_btc |= ((bit_timing->phase_seg1 + bit_timing->prop_seg - 1) 295 & 0xF) << 3; 296 if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES) { 297 if (bit_timing->brp > 4) 298 can_btc |= HECC_CANBTC_SAM; 299 else 300 netdev_warn(priv->ndev, "WARN: Triple" 301 "sampling not set due to h/w limitations"); 302 } 303 can_btc |= ((bit_timing->sjw - 1) & 0x3) << 8; 304 can_btc |= ((bit_timing->brp - 1) & 0xFF) << 16; 305 306 /* ERM being set to 0 by default meaning resync at falling edge */ 307 308 hecc_write(priv, HECC_CANBTC, can_btc); 309 netdev_info(priv->ndev, "setting CANBTC=%#x\n", can_btc); 310 311 return 0; 312 } 313 314 static void ti_hecc_transceiver_switch(const struct ti_hecc_priv *priv, 315 int on) 316 { 317 if (priv->transceiver_switch) 318 priv->transceiver_switch(on); 319 } 320 321 static void ti_hecc_reset(struct net_device *ndev) 322 { 323 u32 cnt; 324 struct ti_hecc_priv *priv = netdev_priv(ndev); 325 326 netdev_dbg(ndev, "resetting hecc ...\n"); 327 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SRES); 328 329 /* Set change control request and wait till enabled */ 330 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 331 332 /* 333 * INFO: It has been observed that at times CCE bit may not be 334 * set and hw seems to be ok even if this bit is not set so 335 * timing out with a timing of 1ms to respect the specs 336 */ 337 cnt = HECC_CCE_WAIT_COUNT; 338 while (!hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 339 --cnt; 340 udelay(10); 341 } 342 343 /* 344 * Note: On HECC, BTC can be programmed only in initialization mode, so 345 * it is expected that the can bittiming parameters are set via ip 346 * utility before the device is opened 347 */ 348 ti_hecc_set_btc(priv); 349 350 /* Clear CCR (and CANMC register) and wait for CCE = 0 enable */ 351 hecc_write(priv, HECC_CANMC, 0); 352 353 /* 354 * INFO: CAN net stack handles bus off and hence disabling auto-bus-on 355 * hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_ABO); 356 */ 357 358 /* 359 * INFO: It has been observed that at times CCE bit may not be 360 * set and hw seems to be ok even if this bit is not set so 361 */ 362 cnt = HECC_CCE_WAIT_COUNT; 363 while (hecc_get_bit(priv, HECC_CANES, HECC_CANES_CCE) && cnt != 0) { 364 --cnt; 365 udelay(10); 366 } 367 368 /* Enable TX and RX I/O Control pins */ 369 hecc_write(priv, HECC_CANTIOC, HECC_CANTIOC_EN); 370 hecc_write(priv, HECC_CANRIOC, HECC_CANRIOC_EN); 371 372 /* Clear registers for clean operation */ 373 hecc_write(priv, HECC_CANTA, HECC_SET_REG); 374 hecc_write(priv, HECC_CANRMP, HECC_SET_REG); 375 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 376 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 377 hecc_write(priv, HECC_CANME, 0); 378 hecc_write(priv, HECC_CANMD, 0); 379 380 /* SCC compat mode NOT supported (and not needed too) */ 381 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_SCM); 382 } 383 384 static void ti_hecc_start(struct net_device *ndev) 385 { 386 struct ti_hecc_priv *priv = netdev_priv(ndev); 387 u32 cnt, mbxno, mbx_mask; 388 389 /* put HECC in initialization mode and set btc */ 390 ti_hecc_reset(ndev); 391 392 priv->tx_head = priv->tx_tail = HECC_TX_MASK; 393 priv->rx_next = HECC_RX_FIRST_MBOX; 394 395 /* Enable local and global acceptance mask registers */ 396 hecc_write(priv, HECC_CANGAM, HECC_SET_REG); 397 398 /* Prepare configured mailboxes to receive messages */ 399 for (cnt = 0; cnt < HECC_MAX_RX_MBOX; cnt++) { 400 mbxno = HECC_MAX_MAILBOXES - 1 - cnt; 401 mbx_mask = BIT(mbxno); 402 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 403 hecc_write_mbx(priv, mbxno, HECC_CANMID, HECC_CANMID_AME); 404 hecc_write_lam(priv, mbxno, HECC_SET_REG); 405 hecc_set_bit(priv, HECC_CANMD, mbx_mask); 406 hecc_set_bit(priv, HECC_CANME, mbx_mask); 407 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 408 } 409 410 /* Prevent message over-write & Enable interrupts */ 411 hecc_write(priv, HECC_CANOPC, HECC_SET_REG); 412 if (priv->int_line) { 413 hecc_write(priv, HECC_CANMIL, HECC_SET_REG); 414 hecc_write(priv, HECC_CANGIM, HECC_CANGIM_DEF_MASK | 415 HECC_CANGIM_I1EN | HECC_CANGIM_SIL); 416 } else { 417 hecc_write(priv, HECC_CANMIL, 0); 418 hecc_write(priv, HECC_CANGIM, 419 HECC_CANGIM_DEF_MASK | HECC_CANGIM_I0EN); 420 } 421 priv->can.state = CAN_STATE_ERROR_ACTIVE; 422 } 423 424 static void ti_hecc_stop(struct net_device *ndev) 425 { 426 struct ti_hecc_priv *priv = netdev_priv(ndev); 427 428 /* Disable interrupts and disable mailboxes */ 429 hecc_write(priv, HECC_CANGIM, 0); 430 hecc_write(priv, HECC_CANMIM, 0); 431 hecc_write(priv, HECC_CANME, 0); 432 priv->can.state = CAN_STATE_STOPPED; 433 } 434 435 static int ti_hecc_do_set_mode(struct net_device *ndev, enum can_mode mode) 436 { 437 int ret = 0; 438 439 switch (mode) { 440 case CAN_MODE_START: 441 ti_hecc_start(ndev); 442 netif_wake_queue(ndev); 443 break; 444 default: 445 ret = -EOPNOTSUPP; 446 break; 447 } 448 449 return ret; 450 } 451 452 static int ti_hecc_get_berr_counter(const struct net_device *ndev, 453 struct can_berr_counter *bec) 454 { 455 struct ti_hecc_priv *priv = netdev_priv(ndev); 456 457 bec->txerr = hecc_read(priv, HECC_CANTEC); 458 bec->rxerr = hecc_read(priv, HECC_CANREC); 459 460 return 0; 461 } 462 463 /* 464 * ti_hecc_xmit: HECC Transmit 465 * 466 * The transmit mailboxes start from 0 to HECC_MAX_TX_MBOX. In HECC the 467 * priority of the mailbox for tranmission is dependent upon priority setting 468 * field in mailbox registers. The mailbox with highest value in priority field 469 * is transmitted first. Only when two mailboxes have the same value in 470 * priority field the highest numbered mailbox is transmitted first. 471 * 472 * To utilize the HECC priority feature as described above we start with the 473 * highest numbered mailbox with highest priority level and move on to the next 474 * mailbox with the same priority level and so on. Once we loop through all the 475 * transmit mailboxes we choose the next priority level (lower) and so on 476 * until we reach the lowest priority level on the lowest numbered mailbox 477 * when we stop transmission until all mailboxes are transmitted and then 478 * restart at highest numbered mailbox with highest priority. 479 * 480 * Two counters (head and tail) are used to track the next mailbox to transmit 481 * and to track the echo buffer for already transmitted mailbox. The queue 482 * is stopped when all the mailboxes are busy or when there is a priority 483 * value roll-over happens. 484 */ 485 static netdev_tx_t ti_hecc_xmit(struct sk_buff *skb, struct net_device *ndev) 486 { 487 struct ti_hecc_priv *priv = netdev_priv(ndev); 488 struct can_frame *cf = (struct can_frame *)skb->data; 489 u32 mbxno, mbx_mask, data; 490 unsigned long flags; 491 492 if (can_dropped_invalid_skb(ndev, skb)) 493 return NETDEV_TX_OK; 494 495 mbxno = get_tx_head_mb(priv); 496 mbx_mask = BIT(mbxno); 497 spin_lock_irqsave(&priv->mbx_lock, flags); 498 if (unlikely(hecc_read(priv, HECC_CANME) & mbx_mask)) { 499 spin_unlock_irqrestore(&priv->mbx_lock, flags); 500 netif_stop_queue(ndev); 501 netdev_err(priv->ndev, 502 "BUG: TX mbx not ready tx_head=%08X, tx_tail=%08X\n", 503 priv->tx_head, priv->tx_tail); 504 return NETDEV_TX_BUSY; 505 } 506 spin_unlock_irqrestore(&priv->mbx_lock, flags); 507 508 /* Prepare mailbox for transmission */ 509 data = cf->can_dlc | (get_tx_head_prio(priv) << 8); 510 if (cf->can_id & CAN_RTR_FLAG) /* Remote transmission request */ 511 data |= HECC_CANMCF_RTR; 512 hecc_write_mbx(priv, mbxno, HECC_CANMCF, data); 513 514 if (cf->can_id & CAN_EFF_FLAG) /* Extended frame format */ 515 data = (cf->can_id & CAN_EFF_MASK) | HECC_CANMID_IDE; 516 else /* Standard frame format */ 517 data = (cf->can_id & CAN_SFF_MASK) << 18; 518 hecc_write_mbx(priv, mbxno, HECC_CANMID, data); 519 hecc_write_mbx(priv, mbxno, HECC_CANMDL, 520 be32_to_cpu(*(__be32 *)(cf->data))); 521 if (cf->can_dlc > 4) 522 hecc_write_mbx(priv, mbxno, HECC_CANMDH, 523 be32_to_cpu(*(__be32 *)(cf->data + 4))); 524 else 525 *(u32 *)(cf->data + 4) = 0; 526 can_put_echo_skb(skb, ndev, mbxno); 527 528 spin_lock_irqsave(&priv->mbx_lock, flags); 529 --priv->tx_head; 530 if ((hecc_read(priv, HECC_CANME) & BIT(get_tx_head_mb(priv))) || 531 (priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK) { 532 netif_stop_queue(ndev); 533 } 534 hecc_set_bit(priv, HECC_CANME, mbx_mask); 535 spin_unlock_irqrestore(&priv->mbx_lock, flags); 536 537 hecc_clear_bit(priv, HECC_CANMD, mbx_mask); 538 hecc_set_bit(priv, HECC_CANMIM, mbx_mask); 539 hecc_write(priv, HECC_CANTRS, mbx_mask); 540 541 return NETDEV_TX_OK; 542 } 543 544 static int ti_hecc_rx_pkt(struct ti_hecc_priv *priv, int mbxno) 545 { 546 struct net_device_stats *stats = &priv->ndev->stats; 547 struct can_frame *cf; 548 struct sk_buff *skb; 549 u32 data, mbx_mask; 550 unsigned long flags; 551 552 skb = alloc_can_skb(priv->ndev, &cf); 553 if (!skb) { 554 if (printk_ratelimit()) 555 netdev_err(priv->ndev, 556 "ti_hecc_rx_pkt: alloc_can_skb() failed\n"); 557 return -ENOMEM; 558 } 559 560 mbx_mask = BIT(mbxno); 561 data = hecc_read_mbx(priv, mbxno, HECC_CANMID); 562 if (data & HECC_CANMID_IDE) 563 cf->can_id = (data & CAN_EFF_MASK) | CAN_EFF_FLAG; 564 else 565 cf->can_id = (data >> 18) & CAN_SFF_MASK; 566 data = hecc_read_mbx(priv, mbxno, HECC_CANMCF); 567 if (data & HECC_CANMCF_RTR) 568 cf->can_id |= CAN_RTR_FLAG; 569 cf->can_dlc = get_can_dlc(data & 0xF); 570 data = hecc_read_mbx(priv, mbxno, HECC_CANMDL); 571 *(__be32 *)(cf->data) = cpu_to_be32(data); 572 if (cf->can_dlc > 4) { 573 data = hecc_read_mbx(priv, mbxno, HECC_CANMDH); 574 *(__be32 *)(cf->data + 4) = cpu_to_be32(data); 575 } 576 spin_lock_irqsave(&priv->mbx_lock, flags); 577 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 578 hecc_write(priv, HECC_CANRMP, mbx_mask); 579 /* enable mailbox only if it is part of rx buffer mailboxes */ 580 if (priv->rx_next < HECC_RX_BUFFER_MBOX) 581 hecc_set_bit(priv, HECC_CANME, mbx_mask); 582 spin_unlock_irqrestore(&priv->mbx_lock, flags); 583 584 stats->rx_bytes += cf->can_dlc; 585 can_led_event(priv->ndev, CAN_LED_EVENT_RX); 586 netif_receive_skb(skb); 587 stats->rx_packets++; 588 589 return 0; 590 } 591 592 /* 593 * ti_hecc_rx_poll - HECC receive pkts 594 * 595 * The receive mailboxes start from highest numbered mailbox till last xmit 596 * mailbox. On CAN frame reception the hardware places the data into highest 597 * numbered mailbox that matches the CAN ID filter. Since all receive mailboxes 598 * have same filtering (ALL CAN frames) packets will arrive in the highest 599 * available RX mailbox and we need to ensure in-order packet reception. 600 * 601 * To ensure the packets are received in the right order we logically divide 602 * the RX mailboxes into main and buffer mailboxes. Packets are received as per 603 * mailbox priotity (higher to lower) in the main bank and once it is full we 604 * disable further reception into main mailboxes. While the main mailboxes are 605 * processed in NAPI, further packets are received in buffer mailboxes. 606 * 607 * We maintain a RX next mailbox counter to process packets and once all main 608 * mailboxe packets are passed to the upper stack we enable all of them but 609 * continue to process packets received in buffer mailboxes. With each packet 610 * received from buffer mailbox we enable it immediately so as to handle the 611 * overflow from higher mailboxes. 612 */ 613 static int ti_hecc_rx_poll(struct napi_struct *napi, int quota) 614 { 615 struct net_device *ndev = napi->dev; 616 struct ti_hecc_priv *priv = netdev_priv(ndev); 617 u32 num_pkts = 0; 618 u32 mbx_mask; 619 unsigned long pending_pkts, flags; 620 621 if (!netif_running(ndev)) 622 return 0; 623 624 while ((pending_pkts = hecc_read(priv, HECC_CANRMP)) && 625 num_pkts < quota) { 626 mbx_mask = BIT(priv->rx_next); /* next rx mailbox to process */ 627 if (mbx_mask & pending_pkts) { 628 if (ti_hecc_rx_pkt(priv, priv->rx_next) < 0) 629 return num_pkts; 630 ++num_pkts; 631 } else if (priv->rx_next > HECC_RX_BUFFER_MBOX) { 632 break; /* pkt not received yet */ 633 } 634 --priv->rx_next; 635 if (priv->rx_next == HECC_RX_BUFFER_MBOX) { 636 /* enable high bank mailboxes */ 637 spin_lock_irqsave(&priv->mbx_lock, flags); 638 mbx_mask = hecc_read(priv, HECC_CANME); 639 mbx_mask |= HECC_RX_HIGH_MBOX_MASK; 640 hecc_write(priv, HECC_CANME, mbx_mask); 641 spin_unlock_irqrestore(&priv->mbx_lock, flags); 642 } else if (priv->rx_next == HECC_MAX_TX_MBOX - 1) { 643 priv->rx_next = HECC_RX_FIRST_MBOX; 644 break; 645 } 646 } 647 648 /* Enable packet interrupt if all pkts are handled */ 649 if (hecc_read(priv, HECC_CANRMP) == 0) { 650 napi_complete(napi); 651 /* Re-enable RX mailbox interrupts */ 652 mbx_mask = hecc_read(priv, HECC_CANMIM); 653 mbx_mask |= HECC_TX_MBOX_MASK; 654 hecc_write(priv, HECC_CANMIM, mbx_mask); 655 } 656 657 return num_pkts; 658 } 659 660 static int ti_hecc_error(struct net_device *ndev, int int_status, 661 int err_status) 662 { 663 struct ti_hecc_priv *priv = netdev_priv(ndev); 664 struct net_device_stats *stats = &ndev->stats; 665 struct can_frame *cf; 666 struct sk_buff *skb; 667 668 /* propagate the error condition to the can stack */ 669 skb = alloc_can_err_skb(ndev, &cf); 670 if (!skb) { 671 if (printk_ratelimit()) 672 netdev_err(priv->ndev, 673 "ti_hecc_error: alloc_can_err_skb() failed\n"); 674 return -ENOMEM; 675 } 676 677 if (int_status & HECC_CANGIF_WLIF) { /* warning level int */ 678 if ((int_status & HECC_CANGIF_BOIF) == 0) { 679 priv->can.state = CAN_STATE_ERROR_WARNING; 680 ++priv->can.can_stats.error_warning; 681 cf->can_id |= CAN_ERR_CRTL; 682 if (hecc_read(priv, HECC_CANTEC) > 96) 683 cf->data[1] |= CAN_ERR_CRTL_TX_WARNING; 684 if (hecc_read(priv, HECC_CANREC) > 96) 685 cf->data[1] |= CAN_ERR_CRTL_RX_WARNING; 686 } 687 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EW); 688 netdev_dbg(priv->ndev, "Error Warning interrupt\n"); 689 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 690 } 691 692 if (int_status & HECC_CANGIF_EPIF) { /* error passive int */ 693 if ((int_status & HECC_CANGIF_BOIF) == 0) { 694 priv->can.state = CAN_STATE_ERROR_PASSIVE; 695 ++priv->can.can_stats.error_passive; 696 cf->can_id |= CAN_ERR_CRTL; 697 if (hecc_read(priv, HECC_CANTEC) > 127) 698 cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE; 699 if (hecc_read(priv, HECC_CANREC) > 127) 700 cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE; 701 } 702 hecc_set_bit(priv, HECC_CANES, HECC_CANES_EP); 703 netdev_dbg(priv->ndev, "Error passive interrupt\n"); 704 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 705 } 706 707 /* 708 * Need to check busoff condition in error status register too to 709 * ensure warning interrupts don't hog the system 710 */ 711 if ((int_status & HECC_CANGIF_BOIF) || (err_status & HECC_CANES_BO)) { 712 priv->can.state = CAN_STATE_BUS_OFF; 713 cf->can_id |= CAN_ERR_BUSOFF; 714 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BO); 715 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_CCR); 716 /* Disable all interrupts in bus-off to avoid int hog */ 717 hecc_write(priv, HECC_CANGIM, 0); 718 ++priv->can.can_stats.bus_off; 719 can_bus_off(ndev); 720 } 721 722 if (err_status & HECC_BUS_ERROR) { 723 ++priv->can.can_stats.bus_error; 724 cf->can_id |= CAN_ERR_BUSERROR | CAN_ERR_PROT; 725 cf->data[2] |= CAN_ERR_PROT_UNSPEC; 726 if (err_status & HECC_CANES_FE) { 727 hecc_set_bit(priv, HECC_CANES, HECC_CANES_FE); 728 cf->data[2] |= CAN_ERR_PROT_FORM; 729 } 730 if (err_status & HECC_CANES_BE) { 731 hecc_set_bit(priv, HECC_CANES, HECC_CANES_BE); 732 cf->data[2] |= CAN_ERR_PROT_BIT; 733 } 734 if (err_status & HECC_CANES_SE) { 735 hecc_set_bit(priv, HECC_CANES, HECC_CANES_SE); 736 cf->data[2] |= CAN_ERR_PROT_STUFF; 737 } 738 if (err_status & HECC_CANES_CRCE) { 739 hecc_set_bit(priv, HECC_CANES, HECC_CANES_CRCE); 740 cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ | 741 CAN_ERR_PROT_LOC_CRC_DEL; 742 } 743 if (err_status & HECC_CANES_ACKE) { 744 hecc_set_bit(priv, HECC_CANES, HECC_CANES_ACKE); 745 cf->data[3] |= CAN_ERR_PROT_LOC_ACK | 746 CAN_ERR_PROT_LOC_ACK_DEL; 747 } 748 } 749 750 stats->rx_packets++; 751 stats->rx_bytes += cf->can_dlc; 752 netif_rx(skb); 753 754 return 0; 755 } 756 757 static irqreturn_t ti_hecc_interrupt(int irq, void *dev_id) 758 { 759 struct net_device *ndev = (struct net_device *)dev_id; 760 struct ti_hecc_priv *priv = netdev_priv(ndev); 761 struct net_device_stats *stats = &ndev->stats; 762 u32 mbxno, mbx_mask, int_status, err_status; 763 unsigned long ack, flags; 764 765 int_status = hecc_read(priv, 766 (priv->int_line) ? HECC_CANGIF1 : HECC_CANGIF0); 767 768 if (!int_status) 769 return IRQ_NONE; 770 771 err_status = hecc_read(priv, HECC_CANES); 772 if (err_status & (HECC_BUS_ERROR | HECC_CANES_BO | 773 HECC_CANES_EP | HECC_CANES_EW)) 774 ti_hecc_error(ndev, int_status, err_status); 775 776 if (int_status & HECC_CANGIF_GMIF) { 777 while (priv->tx_tail - priv->tx_head > 0) { 778 mbxno = get_tx_tail_mb(priv); 779 mbx_mask = BIT(mbxno); 780 if (!(mbx_mask & hecc_read(priv, HECC_CANTA))) 781 break; 782 hecc_clear_bit(priv, HECC_CANMIM, mbx_mask); 783 hecc_write(priv, HECC_CANTA, mbx_mask); 784 spin_lock_irqsave(&priv->mbx_lock, flags); 785 hecc_clear_bit(priv, HECC_CANME, mbx_mask); 786 spin_unlock_irqrestore(&priv->mbx_lock, flags); 787 stats->tx_bytes += hecc_read_mbx(priv, mbxno, 788 HECC_CANMCF) & 0xF; 789 stats->tx_packets++; 790 can_led_event(ndev, CAN_LED_EVENT_TX); 791 can_get_echo_skb(ndev, mbxno); 792 --priv->tx_tail; 793 } 794 795 /* restart queue if wrap-up or if queue stalled on last pkt */ 796 if (((priv->tx_head == priv->tx_tail) && 797 ((priv->tx_head & HECC_TX_MASK) != HECC_TX_MASK)) || 798 (((priv->tx_tail & HECC_TX_MASK) == HECC_TX_MASK) && 799 ((priv->tx_head & HECC_TX_MASK) == HECC_TX_MASK))) 800 netif_wake_queue(ndev); 801 802 /* Disable RX mailbox interrupts and let NAPI reenable them */ 803 if (hecc_read(priv, HECC_CANRMP)) { 804 ack = hecc_read(priv, HECC_CANMIM); 805 ack &= BIT(HECC_MAX_TX_MBOX) - 1; 806 hecc_write(priv, HECC_CANMIM, ack); 807 napi_schedule(&priv->napi); 808 } 809 } 810 811 /* clear all interrupt conditions - read back to avoid spurious ints */ 812 if (priv->int_line) { 813 hecc_write(priv, HECC_CANGIF1, HECC_SET_REG); 814 int_status = hecc_read(priv, HECC_CANGIF1); 815 } else { 816 hecc_write(priv, HECC_CANGIF0, HECC_SET_REG); 817 int_status = hecc_read(priv, HECC_CANGIF0); 818 } 819 820 return IRQ_HANDLED; 821 } 822 823 static int ti_hecc_open(struct net_device *ndev) 824 { 825 struct ti_hecc_priv *priv = netdev_priv(ndev); 826 int err; 827 828 err = request_irq(ndev->irq, ti_hecc_interrupt, IRQF_SHARED, 829 ndev->name, ndev); 830 if (err) { 831 netdev_err(ndev, "error requesting interrupt\n"); 832 return err; 833 } 834 835 ti_hecc_transceiver_switch(priv, 1); 836 837 /* Open common can device */ 838 err = open_candev(ndev); 839 if (err) { 840 netdev_err(ndev, "open_candev() failed %d\n", err); 841 ti_hecc_transceiver_switch(priv, 0); 842 free_irq(ndev->irq, ndev); 843 return err; 844 } 845 846 can_led_event(ndev, CAN_LED_EVENT_OPEN); 847 848 ti_hecc_start(ndev); 849 napi_enable(&priv->napi); 850 netif_start_queue(ndev); 851 852 return 0; 853 } 854 855 static int ti_hecc_close(struct net_device *ndev) 856 { 857 struct ti_hecc_priv *priv = netdev_priv(ndev); 858 859 netif_stop_queue(ndev); 860 napi_disable(&priv->napi); 861 ti_hecc_stop(ndev); 862 free_irq(ndev->irq, ndev); 863 close_candev(ndev); 864 ti_hecc_transceiver_switch(priv, 0); 865 866 can_led_event(ndev, CAN_LED_EVENT_STOP); 867 868 return 0; 869 } 870 871 static const struct net_device_ops ti_hecc_netdev_ops = { 872 .ndo_open = ti_hecc_open, 873 .ndo_stop = ti_hecc_close, 874 .ndo_start_xmit = ti_hecc_xmit, 875 .ndo_change_mtu = can_change_mtu, 876 }; 877 878 static int ti_hecc_probe(struct platform_device *pdev) 879 { 880 struct net_device *ndev = (struct net_device *)0; 881 struct ti_hecc_priv *priv; 882 struct ti_hecc_platform_data *pdata; 883 struct resource *mem, *irq; 884 void __iomem *addr; 885 int err = -ENODEV; 886 887 pdata = dev_get_platdata(&pdev->dev); 888 if (!pdata) { 889 dev_err(&pdev->dev, "No platform data\n"); 890 goto probe_exit; 891 } 892 893 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 894 if (!mem) { 895 dev_err(&pdev->dev, "No mem resources\n"); 896 goto probe_exit; 897 } 898 irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 899 if (!irq) { 900 dev_err(&pdev->dev, "No irq resource\n"); 901 goto probe_exit; 902 } 903 if (!request_mem_region(mem->start, resource_size(mem), pdev->name)) { 904 dev_err(&pdev->dev, "HECC region already claimed\n"); 905 err = -EBUSY; 906 goto probe_exit; 907 } 908 addr = ioremap(mem->start, resource_size(mem)); 909 if (!addr) { 910 dev_err(&pdev->dev, "ioremap failed\n"); 911 err = -ENOMEM; 912 goto probe_exit_free_region; 913 } 914 915 ndev = alloc_candev(sizeof(struct ti_hecc_priv), HECC_MAX_TX_MBOX); 916 if (!ndev) { 917 dev_err(&pdev->dev, "alloc_candev failed\n"); 918 err = -ENOMEM; 919 goto probe_exit_iounmap; 920 } 921 922 priv = netdev_priv(ndev); 923 priv->ndev = ndev; 924 priv->base = addr; 925 priv->scc_ram_offset = pdata->scc_ram_offset; 926 priv->hecc_ram_offset = pdata->hecc_ram_offset; 927 priv->mbx_offset = pdata->mbx_offset; 928 priv->int_line = pdata->int_line; 929 priv->transceiver_switch = pdata->transceiver_switch; 930 931 priv->can.bittiming_const = &ti_hecc_bittiming_const; 932 priv->can.do_set_mode = ti_hecc_do_set_mode; 933 priv->can.do_get_berr_counter = ti_hecc_get_berr_counter; 934 priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES; 935 936 spin_lock_init(&priv->mbx_lock); 937 ndev->irq = irq->start; 938 ndev->flags |= IFF_ECHO; 939 platform_set_drvdata(pdev, ndev); 940 SET_NETDEV_DEV(ndev, &pdev->dev); 941 ndev->netdev_ops = &ti_hecc_netdev_ops; 942 943 priv->clk = clk_get(&pdev->dev, "hecc_ck"); 944 if (IS_ERR(priv->clk)) { 945 dev_err(&pdev->dev, "No clock available\n"); 946 err = PTR_ERR(priv->clk); 947 priv->clk = NULL; 948 goto probe_exit_candev; 949 } 950 priv->can.clock.freq = clk_get_rate(priv->clk); 951 netif_napi_add(ndev, &priv->napi, ti_hecc_rx_poll, 952 HECC_DEF_NAPI_WEIGHT); 953 954 clk_enable(priv->clk); 955 err = register_candev(ndev); 956 if (err) { 957 dev_err(&pdev->dev, "register_candev() failed\n"); 958 goto probe_exit_clk; 959 } 960 961 devm_can_led_init(ndev); 962 963 dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%u)\n", 964 priv->base, (u32) ndev->irq); 965 966 return 0; 967 968 probe_exit_clk: 969 clk_put(priv->clk); 970 probe_exit_candev: 971 free_candev(ndev); 972 probe_exit_iounmap: 973 iounmap(addr); 974 probe_exit_free_region: 975 release_mem_region(mem->start, resource_size(mem)); 976 probe_exit: 977 return err; 978 } 979 980 static int ti_hecc_remove(struct platform_device *pdev) 981 { 982 struct resource *res; 983 struct net_device *ndev = platform_get_drvdata(pdev); 984 struct ti_hecc_priv *priv = netdev_priv(ndev); 985 986 unregister_candev(ndev); 987 clk_disable(priv->clk); 988 clk_put(priv->clk); 989 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 990 iounmap(priv->base); 991 release_mem_region(res->start, resource_size(res)); 992 free_candev(ndev); 993 994 return 0; 995 } 996 997 998 #ifdef CONFIG_PM 999 static int ti_hecc_suspend(struct platform_device *pdev, pm_message_t state) 1000 { 1001 struct net_device *dev = platform_get_drvdata(pdev); 1002 struct ti_hecc_priv *priv = netdev_priv(dev); 1003 1004 if (netif_running(dev)) { 1005 netif_stop_queue(dev); 1006 netif_device_detach(dev); 1007 } 1008 1009 hecc_set_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1010 priv->can.state = CAN_STATE_SLEEPING; 1011 1012 clk_disable(priv->clk); 1013 1014 return 0; 1015 } 1016 1017 static int ti_hecc_resume(struct platform_device *pdev) 1018 { 1019 struct net_device *dev = platform_get_drvdata(pdev); 1020 struct ti_hecc_priv *priv = netdev_priv(dev); 1021 1022 clk_enable(priv->clk); 1023 1024 hecc_clear_bit(priv, HECC_CANMC, HECC_CANMC_PDR); 1025 priv->can.state = CAN_STATE_ERROR_ACTIVE; 1026 1027 if (netif_running(dev)) { 1028 netif_device_attach(dev); 1029 netif_start_queue(dev); 1030 } 1031 1032 return 0; 1033 } 1034 #else 1035 #define ti_hecc_suspend NULL 1036 #define ti_hecc_resume NULL 1037 #endif 1038 1039 /* TI HECC netdevice driver: platform driver structure */ 1040 static struct platform_driver ti_hecc_driver = { 1041 .driver = { 1042 .name = DRV_NAME, 1043 }, 1044 .probe = ti_hecc_probe, 1045 .remove = ti_hecc_remove, 1046 .suspend = ti_hecc_suspend, 1047 .resume = ti_hecc_resume, 1048 }; 1049 1050 module_platform_driver(ti_hecc_driver); 1051 1052 MODULE_AUTHOR("Anant Gole <anantgole@ti.com>"); 1053 MODULE_LICENSE("GPL v2"); 1054 MODULE_DESCRIPTION(DRV_DESC); 1055 MODULE_ALIAS("platform:" DRV_NAME); 1056