drivers/net/can/spi/hi311x.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
   3  *
   4  * Copyright(C) Timesys Corporation 2016
   5  *
   6  * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
   7  * Copyright 2009 Christian Pellegrin EVOL S.r.l.
   8  * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
   9  * Copyright 2006 Arcom Control Systems Ltd.
  10  *
  11  * Based on CAN bus driver for the CCAN controller written by
  12  * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
  13  * - Simon Kallweit, intefo AG
  14  * Copyright 2007
  15  */
  16
  17 #include <linux/can/core.h>
  18 #include <linux/can/dev.h>
  19 #include <linux/can/led.h>
  20 #include <linux/clk.h>
  21 #include <linux/completion.h>
  22 #include <linux/delay.h>
  23 #include <linux/device.h>
  24 #include <linux/freezer.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/io.h>
  27 #include <linux/kernel.h>
  28 #include <linux/module.h>
  29 #include <linux/netdevice.h>
  30 #include <linux/of.h>
  31 #include <linux/of_device.h>
  32 #include <linux/platform_device.h>
  33 #include <linux/regulator/consumer.h>
  34 #include <linux/slab.h>
  35 #include <linux/spi/spi.h>
  36 #include <linux/uaccess.h>
  37
  38 #define HI3110_MASTER_RESET 0x56
  39 #define HI3110_READ_CTRL0 0xD2
  40 #define HI3110_READ_CTRL1 0xD4
  41 #define HI3110_READ_STATF 0xE2
  42 #define HI3110_WRITE_CTRL0 0x14
  43 #define HI3110_WRITE_CTRL1 0x16
  44 #define HI3110_WRITE_INTE 0x1C
  45 #define HI3110_WRITE_BTR0 0x18
  46 #define HI3110_WRITE_BTR1 0x1A
  47 #define HI3110_READ_BTR0 0xD6
  48 #define HI3110_READ_BTR1 0xD8
  49 #define HI3110_READ_INTF 0xDE
  50 #define HI3110_READ_ERR 0xDC
  51 #define HI3110_READ_FIFO_WOTIME 0x48
  52 #define HI3110_WRITE_FIFO 0x12
  53 #define HI3110_READ_MESSTAT 0xDA
  54 #define HI3110_READ_REC 0xEA
  55 #define HI3110_READ_TEC 0xEC
  56
  57 #define HI3110_CTRL0_MODE_MASK (7 << 5)
  58 #define HI3110_CTRL0_NORMAL_MODE (0 << 5)
  59 #define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
  60 #define HI3110_CTRL0_MONITOR_MODE (2 << 5)
  61 #define HI3110_CTRL0_SLEEP_MODE (3 << 5)
  62 #define HI3110_CTRL0_INIT_MODE (4 << 5)
  63
  64 #define HI3110_CTRL1_TXEN BIT(7)
  65
  66 #define HI3110_INT_RXTMP BIT(7)
  67 #define HI3110_INT_RXFIFO BIT(6)
  68 #define HI3110_INT_TXCPLT BIT(5)
  69 #define HI3110_INT_BUSERR BIT(4)
  70 #define HI3110_INT_MCHG BIT(3)
  71 #define HI3110_INT_WAKEUP BIT(2)
  72 #define HI3110_INT_F1MESS BIT(1)
  73 #define HI3110_INT_F0MESS BIT(0)
  74
  75 #define HI3110_ERR_BUSOFF BIT(7)
  76 #define HI3110_ERR_TXERRP BIT(6)
  77 #define HI3110_ERR_RXERRP BIT(5)
  78 #define HI3110_ERR_BITERR BIT(4)
  79 #define HI3110_ERR_FRMERR BIT(3)
  80 #define HI3110_ERR_CRCERR BIT(2)
  81 #define HI3110_ERR_ACKERR BIT(1)
  82 #define HI3110_ERR_STUFERR BIT(0)
  83 #define HI3110_ERR_PROTOCOL_MASK (0x1F)
  84 #define HI3110_ERR_PASSIVE_MASK (0x60)
  85
  86 #define HI3110_STAT_RXFMTY BIT(1)
  87 #define HI3110_STAT_BUSOFF BIT(2)
  88 #define HI3110_STAT_ERRP BIT(3)
  89 #define HI3110_STAT_ERRW BIT(4)
  90 #define HI3110_STAT_TXMTY BIT(7)
  91
  92 #define HI3110_BTR0_SJW_SHIFT 6
  93 #define HI3110_BTR0_BRP_SHIFT 0
  94
  95 #define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
  96 #define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
  97 #define HI3110_BTR1_TSEG2_SHIFT 4
  98 #define HI3110_BTR1_TSEG1_SHIFT 0
  99
 100 #define HI3110_FIFO_WOTIME_TAG_OFF 0
 101 #define HI3110_FIFO_WOTIME_ID_OFF 1
 102 #define HI3110_FIFO_WOTIME_DLC_OFF 5
 103 #define HI3110_FIFO_WOTIME_DAT_OFF 6
 104
 105 #define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
 106 #define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
 107
 108 #define HI3110_FIFO_TAG_OFF 0
 109 #define HI3110_FIFO_ID_OFF 1
 110 #define HI3110_FIFO_STD_DLC_OFF 3
 111 #define HI3110_FIFO_STD_DATA_OFF 4
 112 #define HI3110_FIFO_EXT_DLC_OFF 5
 113 #define HI3110_FIFO_EXT_DATA_OFF 6
 114
 115 #define HI3110_CAN_MAX_DATA_LEN 8
 116 #define HI3110_RX_BUF_LEN 15
 117 #define HI3110_TX_STD_BUF_LEN 12
 118 #define HI3110_TX_EXT_BUF_LEN 14
 119 #define HI3110_CAN_FRAME_MAX_BITS 128
 120 #define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
 121
 122 #define HI3110_TX_ECHO_SKB_MAX 1
 123
 124 #define HI3110_OST_DELAY_MS (10)
 125
 126 #define DEVICE_NAME "hi3110"
 127
 128 static const struct can_bittiming_const hi3110_bittiming_const = {
 129         .name = DEVICE_NAME,
 130         .tseg1_min = 2,
 131         .tseg1_max = 16,
 132         .tseg2_min = 2,
 133         .tseg2_max = 8,
 134         .sjw_max = 4,
 135         .brp_min = 1,
 136         .brp_max = 64,
 137         .brp_inc = 1,
 138 };
 139
 140 enum hi3110_model {
 141         CAN_HI3110_HI3110 = 0x3110,
 142 };
 143
 144 struct hi3110_priv {
 145         struct can_priv can;
 146         struct net_device *net;
 147         struct spi_device *spi;
 148         enum hi3110_model model;
 149
 150         struct mutex hi3110_lock; /* SPI device lock */
 151
 152         u8 *spi_tx_buf;
 153         u8 *spi_rx_buf;
 154
 155         struct sk_buff *tx_skb;
 156         int tx_len;
 157
 158         struct workqueue_struct *wq;
 159         struct work_struct tx_work;
 160         struct work_struct restart_work;
 161
 162         int force_quit;
 163         int after_suspend;
 164 #define HI3110_AFTER_SUSPEND_UP 1
 165 #define HI3110_AFTER_SUSPEND_DOWN 2
 166 #define HI3110_AFTER_SUSPEND_POWER 4
 167 #define HI3110_AFTER_SUSPEND_RESTART 8
 168         int restart_tx;
 169         struct regulator *power;
 170         struct regulator *transceiver;
 171         struct clk *clk;
 172 };
 173
 174 static void hi3110_clean(struct net_device *net)
 175 {
 176         struct hi3110_priv *priv = netdev_priv(net);
 177
 178         if (priv->tx_skb || priv->tx_len)
 179                 net->stats.tx_errors++;
 180         dev_kfree_skb(priv->tx_skb);
 181         if (priv->tx_len)
 182                 can_free_echo_skb(priv->net, 0);
 183         priv->tx_skb = NULL;
 184         priv->tx_len = 0;
 185 }
 186
 187 /* Note about handling of error return of hi3110_spi_trans: accessing
 188  * registers via SPI is not really different conceptually than using
 189  * normal I/O assembler instructions, although it's much more
 190  * complicated from a practical POV. So it's not advisable to always
 191  * check the return value of this function. Imagine that every
 192  * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
 193  * error();", it would be a great mess (well there are some situation
 194  * when exception handling C++ like could be useful after all). So we
 195  * just check that transfers are OK at the beginning of our
 196  * conversation with the chip and to avoid doing really nasty things
 197  * (like injecting bogus packets in the network stack).
 198  */
 199 static int hi3110_spi_trans(struct spi_device *spi, int len)
 200 {
 201         struct hi3110_priv *priv = spi_get_drvdata(spi);
 202         struct spi_transfer t = {
 203                 .tx_buf = priv->spi_tx_buf,
 204                 .rx_buf = priv->spi_rx_buf,
 205                 .len = len,
 206                 .cs_change = 0,
 207         };
 208         struct spi_message m;
 209         int ret;
 210
 211         spi_message_init(&m);
 212         spi_message_add_tail(&t, &m);
 213
 214         ret = spi_sync(spi, &m);
 215
 216         if (ret)
 217                 dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
 218         return ret;
 219 }
 220
 221 static u8 hi3110_cmd(struct spi_device *spi, u8 command)
 222 {
 223         struct hi3110_priv *priv = spi_get_drvdata(spi);
 224
 225         priv->spi_tx_buf[0] = command;
 226         dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
 227
 228         return hi3110_spi_trans(spi, 1);
 229 }
 230
 231 static u8 hi3110_read(struct spi_device *spi, u8 command)
 232 {
 233         struct hi3110_priv *priv = spi_get_drvdata(spi);
 234         u8 val = 0;
 235
 236         priv->spi_tx_buf[0] = command;
 237         hi3110_spi_trans(spi, 2);
 238         val = priv->spi_rx_buf[1];
 239
 240         return val;
 241 }
 242
 243 static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
 244 {
 245         struct hi3110_priv *priv = spi_get_drvdata(spi);
 246
 247         priv->spi_tx_buf[0] = reg;
 248         priv->spi_tx_buf[1] = val;
 249         hi3110_spi_trans(spi, 2);
 250 }
 251
 252 static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
 253 {
 254         struct hi3110_priv *priv = spi_get_drvdata(spi);
 255
 256         priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
 257         memcpy(priv->spi_tx_buf + 1, buf, len);
 258         hi3110_spi_trans(spi, len + 1);
 259 }
 260
 261 static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
 262 {
 263         u8 buf[HI3110_TX_EXT_BUF_LEN];
 264
 265         buf[HI3110_FIFO_TAG_OFF] = 0;
 266
 267         if (frame->can_id & CAN_EFF_FLAG) {
 268                 /* Extended frame */
 269                 buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
 270                 buf[HI3110_FIFO_ID_OFF + 1] =
 271                         (((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
 272                         HI3110_EFF_FLAGS |
 273                         (((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
 274                 buf[HI3110_FIFO_ID_OFF + 2] =
 275                         (frame->can_id & CAN_EFF_MASK) >> 7;
 276                 buf[HI3110_FIFO_ID_OFF + 3] =
 277                         ((frame->can_id & CAN_EFF_MASK) << 1) |
 278                         ((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
 279
 280                 buf[HI3110_FIFO_EXT_DLC_OFF] = frame->can_dlc;
 281
 282                 memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
 283                        frame->data, frame->can_dlc);
 284
 285                 hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
 286                                    (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
 287         } else {
 288                 /* Standard frame */
 289                 buf[HI3110_FIFO_ID_OFF] =   (frame->can_id & CAN_SFF_MASK) >> 3;
 290                 buf[HI3110_FIFO_ID_OFF + 1] =
 291                         ((frame->can_id & CAN_SFF_MASK) << 5) |
 292                         ((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
 293
 294                 buf[HI3110_FIFO_STD_DLC_OFF] = frame->can_dlc;
 295
 296                 memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
 297                        frame->data, frame->can_dlc);
 298
 299                 hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
 300                                    (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
 301         }
 302 }
 303
 304 static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
 305 {
 306         struct hi3110_priv *priv = spi_get_drvdata(spi);
 307
 308         priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
 309         hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
 310         memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
 311 }
 312
 313 static void hi3110_hw_rx(struct spi_device *spi)
 314 {
 315         struct hi3110_priv *priv = spi_get_drvdata(spi);
 316         struct sk_buff *skb;
 317         struct can_frame *frame;
 318         u8 buf[HI3110_RX_BUF_LEN - 1];
 319
 320         skb = alloc_can_skb(priv->net, &frame);
 321         if (!skb) {
 322                 priv->net->stats.rx_dropped++;
 323                 return;
 324         }
 325
 326         hi3110_hw_rx_frame(spi, buf);
 327         if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
 328                 /* IDE is recessive (1), indicating extended 29-bit frame */
 329                 frame->can_id = CAN_EFF_FLAG;
 330                 frame->can_id |=
 331                         (buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
 332                         (((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
 333                         ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
 334                         (buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
 335                         (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
 336         } else {
 337                 /* IDE is dominant (0), frame indicating standard 11-bit */
 338                 frame->can_id =
 339                         (buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
 340                         ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
 341         }
 342
 343         /* Data length */
 344         frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
 345
 346         if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
 347                 frame->can_id |= CAN_RTR_FLAG;
 348         else
 349                 memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
 350                        frame->can_dlc);
 351
 352         priv->net->stats.rx_packets++;
 353         priv->net->stats.rx_bytes += frame->can_dlc;
 354
 355         can_led_event(priv->net, CAN_LED_EVENT_RX);
 356
 357         netif_rx_ni(skb);
 358 }
 359
 360 static void hi3110_hw_sleep(struct spi_device *spi)
 361 {
 362         hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
 363 }
 364
 365 static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
 366                                           struct net_device *net)
 367 {
 368         struct hi3110_priv *priv = netdev_priv(net);
 369         struct spi_device *spi = priv->spi;
 370
 371         if (priv->tx_skb || priv->tx_len) {
 372                 dev_err(&spi->dev, "hard_xmit called while tx busy\n");
 373                 return NETDEV_TX_BUSY;
 374         }
 375
 376         if (can_dropped_invalid_skb(net, skb))
 377                 return NETDEV_TX_OK;
 378
 379         netif_stop_queue(net);
 380         priv->tx_skb = skb;
 381         queue_work(priv->wq, &priv->tx_work);
 382
 383         return NETDEV_TX_OK;
 384 }
 385
 386 static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
 387 {
 388         struct hi3110_priv *priv = netdev_priv(net);
 389
 390         switch (mode) {
 391         case CAN_MODE_START:
 392                 hi3110_clean(net);
 393                 /* We have to delay work since SPI I/O may sleep */
 394                 priv->can.state = CAN_STATE_ERROR_ACTIVE;
 395                 priv->restart_tx = 1;
 396                 if (priv->can.restart_ms == 0)
 397                         priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
 398                 queue_work(priv->wq, &priv->restart_work);
 399                 break;
 400         default:
 401                 return -EOPNOTSUPP;
 402         }
 403
 404         return 0;
 405 }
 406
 407 static int hi3110_get_berr_counter(const struct net_device *net,
 408                                    struct can_berr_counter *bec)
 409 {
 410         struct hi3110_priv *priv = netdev_priv(net);
 411         struct spi_device *spi = priv->spi;
 412
 413         mutex_lock(&priv->hi3110_lock);
 414         bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
 415         bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
 416         mutex_unlock(&priv->hi3110_lock);
 417
 418         return 0;
 419 }
 420
 421 static int hi3110_set_normal_mode(struct spi_device *spi)
 422 {
 423         struct hi3110_priv *priv = spi_get_drvdata(spi);
 424         u8 reg = 0;
 425
 426         hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
 427                      HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
 428
 429         /* Enable TX */
 430         hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
 431
 432         if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 433                 reg = HI3110_CTRL0_LOOPBACK_MODE;
 434         else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 435                 reg = HI3110_CTRL0_MONITOR_MODE;
 436         else
 437                 reg = HI3110_CTRL0_NORMAL_MODE;
 438
 439         hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
 440
 441         /* Wait for the device to enter the mode */
 442         mdelay(HI3110_OST_DELAY_MS);
 443         reg = hi3110_read(spi, HI3110_READ_CTRL0);
 444         if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
 445                 return -EBUSY;
 446
 447         priv->can.state = CAN_STATE_ERROR_ACTIVE;
 448         return 0;
 449 }
 450
 451 static int hi3110_do_set_bittiming(struct net_device *net)
 452 {
 453         struct hi3110_priv *priv = netdev_priv(net);
 454         struct can_bittiming *bt = &priv->can.bittiming;
 455         struct spi_device *spi = priv->spi;
 456
 457         hi3110_write(spi, HI3110_WRITE_BTR0,
 458                      ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
 459                      ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
 460
 461         hi3110_write(spi, HI3110_WRITE_BTR1,
 462                      (priv->can.ctrlmode &
 463                       CAN_CTRLMODE_3_SAMPLES ?
 464                       HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
 465                      ((bt->phase_seg1 + bt->prop_seg - 1)
 466                       << HI3110_BTR1_TSEG1_SHIFT) |
 467                      ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
 468
 469         dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
 470                 hi3110_read(spi, HI3110_READ_BTR0),
 471                 hi3110_read(spi, HI3110_READ_BTR1));
 472
 473         return 0;
 474 }
 475
 476 static int hi3110_setup(struct net_device *net)
 477 {
 478         hi3110_do_set_bittiming(net);
 479         return 0;
 480 }
 481
 482 static int hi3110_hw_reset(struct spi_device *spi)
 483 {
 484         u8 reg;
 485         int ret;
 486
 487         /* Wait for oscillator startup timer after power up */
 488         mdelay(HI3110_OST_DELAY_MS);
 489
 490         ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
 491         if (ret)
 492                 return ret;
 493
 494         /* Wait for oscillator startup timer after reset */
 495         mdelay(HI3110_OST_DELAY_MS);
 496
 497         reg = hi3110_read(spi, HI3110_READ_CTRL0);
 498         if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
 499                 return -ENODEV;
 500
 501         /* As per the datasheet it appears the error flags are
 502          * not cleared on reset. Explicitly clear them by performing a read
 503          */
 504         hi3110_read(spi, HI3110_READ_ERR);
 505
 506         return 0;
 507 }
 508
 509 static int hi3110_hw_probe(struct spi_device *spi)
 510 {
 511         u8 statf;
 512
 513         hi3110_hw_reset(spi);
 514
 515         /* Confirm correct operation by checking against reset values
 516          * in datasheet
 517          */
 518         statf = hi3110_read(spi, HI3110_READ_STATF);
 519
 520         dev_dbg(&spi->dev, "statf: %02X\n", statf);
 521
 522         if (statf != 0x82)
 523                 return -ENODEV;
 524
 525         return 0;
 526 }
 527
 528 static int hi3110_power_enable(struct regulator *reg, int enable)
 529 {
 530         if (IS_ERR_OR_NULL(reg))
 531                 return 0;
 532
 533         if (enable)
 534                 return regulator_enable(reg);
 535         else
 536                 return regulator_disable(reg);
 537 }
 538
 539 static int hi3110_stop(struct net_device *net)
 540 {
 541         struct hi3110_priv *priv = netdev_priv(net);
 542         struct spi_device *spi = priv->spi;
 543
 544         close_candev(net);
 545
 546         priv->force_quit = 1;
 547         free_irq(spi->irq, priv);
 548         destroy_workqueue(priv->wq);
 549         priv->wq = NULL;
 550
 551         mutex_lock(&priv->hi3110_lock);
 552
 553         /* Disable transmit, interrupts and clear flags */
 554         hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
 555         hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
 556         hi3110_read(spi, HI3110_READ_INTF);
 557
 558         hi3110_clean(net);
 559
 560         hi3110_hw_sleep(spi);
 561
 562         hi3110_power_enable(priv->transceiver, 0);
 563
 564         priv->can.state = CAN_STATE_STOPPED;
 565
 566         mutex_unlock(&priv->hi3110_lock);
 567
 568         can_led_event(net, CAN_LED_EVENT_STOP);
 569
 570         return 0;
 571 }
 572
 573 static void hi3110_tx_work_handler(struct work_struct *ws)
 574 {
 575         struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
 576                                                 tx_work);
 577         struct spi_device *spi = priv->spi;
 578         struct net_device *net = priv->net;
 579         struct can_frame *frame;
 580
 581         mutex_lock(&priv->hi3110_lock);
 582         if (priv->tx_skb) {
 583                 if (priv->can.state == CAN_STATE_BUS_OFF) {
 584                         hi3110_clean(net);
 585                 } else {
 586                         frame = (struct can_frame *)priv->tx_skb->data;
 587                         hi3110_hw_tx(spi, frame);
 588                         priv->tx_len = 1 + frame->can_dlc;
 589                         can_put_echo_skb(priv->tx_skb, net, 0);
 590                         priv->tx_skb = NULL;
 591                 }
 592         }
 593         mutex_unlock(&priv->hi3110_lock);
 594 }
 595
 596 static void hi3110_restart_work_handler(struct work_struct *ws)
 597 {
 598         struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
 599                                                 restart_work);
 600         struct spi_device *spi = priv->spi;
 601         struct net_device *net = priv->net;
 602
 603         mutex_lock(&priv->hi3110_lock);
 604         if (priv->after_suspend) {
 605                 hi3110_hw_reset(spi);
 606                 hi3110_setup(net);
 607                 if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
 608                         hi3110_set_normal_mode(spi);
 609                 } else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
 610                         netif_device_attach(net);
 611                         hi3110_clean(net);
 612                         hi3110_set_normal_mode(spi);
 613                         netif_wake_queue(net);
 614                 } else {
 615                         hi3110_hw_sleep(spi);
 616                 }
 617                 priv->after_suspend = 0;
 618                 priv->force_quit = 0;
 619         }
 620
 621         if (priv->restart_tx) {
 622                 priv->restart_tx = 0;
 623                 hi3110_hw_reset(spi);
 624                 hi3110_setup(net);
 625                 hi3110_clean(net);
 626                 hi3110_set_normal_mode(spi);
 627                 netif_wake_queue(net);
 628         }
 629         mutex_unlock(&priv->hi3110_lock);
 630 }
 631
 632 static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 633 {
 634         struct hi3110_priv *priv = dev_id;
 635         struct spi_device *spi = priv->spi;
 636         struct net_device *net = priv->net;
 637
 638         mutex_lock(&priv->hi3110_lock);
 639
 640         while (!priv->force_quit) {
 641                 enum can_state new_state;
 642                 u8 intf, eflag, statf;
 643
 644                 while (!(HI3110_STAT_RXFMTY &
 645                          (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
 646                         hi3110_hw_rx(spi);
 647                 }
 648
 649                 intf = hi3110_read(spi, HI3110_READ_INTF);
 650                 eflag = hi3110_read(spi, HI3110_READ_ERR);
 651                 /* Update can state */
 652                 if (eflag & HI3110_ERR_BUSOFF)
 653                         new_state = CAN_STATE_BUS_OFF;
 654                 else if (eflag & HI3110_ERR_PASSIVE_MASK)
 655                         new_state = CAN_STATE_ERROR_PASSIVE;
 656                 else if (statf & HI3110_STAT_ERRW)
 657                         new_state = CAN_STATE_ERROR_WARNING;
 658                 else
 659                         new_state = CAN_STATE_ERROR_ACTIVE;
 660
 661                 if (new_state != priv->can.state) {
 662                         struct can_frame *cf;
 663                         struct sk_buff *skb;
 664                         enum can_state rx_state, tx_state;
 665                         u8 rxerr, txerr;
 666
 667                         skb = alloc_can_err_skb(net, &cf);
 668                         if (!skb)
 669                                 break;
 670
 671                         txerr = hi3110_read(spi, HI3110_READ_TEC);
 672                         rxerr = hi3110_read(spi, HI3110_READ_REC);
 673                         cf->data[6] = txerr;
 674                         cf->data[7] = rxerr;
 675                         tx_state = txerr >= rxerr ? new_state : 0;
 676                         rx_state = txerr <= rxerr ? new_state : 0;
 677                         can_change_state(net, cf, tx_state, rx_state);
 678                         netif_rx_ni(skb);
 679
 680                         if (new_state == CAN_STATE_BUS_OFF) {
 681                                 can_bus_off(net);
 682                                 if (priv->can.restart_ms == 0) {
 683                                         priv->force_quit = 1;
 684                                         hi3110_hw_sleep(spi);
 685                                         break;
 686                                 }
 687                         }
 688                 }
 689
 690                 /* Update bus errors */
 691                 if ((intf & HI3110_INT_BUSERR) &&
 692                     (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
 693                         struct can_frame *cf;
 694                         struct sk_buff *skb;
 695
 696                         /* Check for protocol errors */
 697                         if (eflag & HI3110_ERR_PROTOCOL_MASK) {
 698                                 skb = alloc_can_err_skb(net, &cf);
 699                                 if (!skb)
 700                                         break;
 701
 702                                 cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 703                                 priv->can.can_stats.bus_error++;
 704                                 priv->net->stats.rx_errors++;
 705                                 if (eflag & HI3110_ERR_BITERR)
 706                                         cf->data[2] |= CAN_ERR_PROT_BIT;
 707                                 else if (eflag & HI3110_ERR_FRMERR)
 708                                         cf->data[2] |= CAN_ERR_PROT_FORM;
 709                                 else if (eflag & HI3110_ERR_STUFERR)
 710                                         cf->data[2] |= CAN_ERR_PROT_STUFF;
 711                                 else if (eflag & HI3110_ERR_CRCERR)
 712                                         cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
 713                                 else if (eflag & HI3110_ERR_ACKERR)
 714                                         cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
 715
 716                                 cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
 717                                 cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
 718                                 netdev_dbg(priv->net, "Bus Error\n");
 719                                 netif_rx_ni(skb);
 720                         }
 721                 }
 722
 723                 if (priv->tx_len && statf & HI3110_STAT_TXMTY) {
 724                         net->stats.tx_packets++;
 725                         net->stats.tx_bytes += priv->tx_len - 1;
 726                         can_led_event(net, CAN_LED_EVENT_TX);
 727                         if (priv->tx_len) {
 728                                 can_get_echo_skb(net, 0);
 729                                 priv->tx_len = 0;
 730                         }
 731                         netif_wake_queue(net);
 732                 }
 733
 734                 if (intf == 0)
 735                         break;
 736         }
 737         mutex_unlock(&priv->hi3110_lock);
 738         return IRQ_HANDLED;
 739 }
 740
 741 static int hi3110_open(struct net_device *net)
 742 {
 743         struct hi3110_priv *priv = netdev_priv(net);
 744         struct spi_device *spi = priv->spi;
 745         unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_HIGH;
 746         int ret;
 747
 748         ret = open_candev(net);
 749         if (ret)
 750                 return ret;
 751
 752         mutex_lock(&priv->hi3110_lock);
 753         hi3110_power_enable(priv->transceiver, 1);
 754
 755         priv->force_quit = 0;
 756         priv->tx_skb = NULL;
 757         priv->tx_len = 0;
 758
 759         ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
 760                                    flags, DEVICE_NAME, priv);
 761         if (ret) {
 762                 dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
 763                 goto out_close;
 764         }
 765
 766         priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
 767                                    0);
 768         if (!priv->wq) {
 769                 ret = -ENOMEM;
 770                 goto out_free_irq;
 771         }
 772         INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
 773         INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
 774
 775         ret = hi3110_hw_reset(spi);
 776         if (ret)
 777                 goto out_free_wq;
 778
 779         ret = hi3110_setup(net);
 780         if (ret)
 781                 goto out_free_wq;
 782
 783         ret = hi3110_set_normal_mode(spi);
 784         if (ret)
 785                 goto out_free_wq;
 786
 787         can_led_event(net, CAN_LED_EVENT_OPEN);
 788         netif_wake_queue(net);
 789         mutex_unlock(&priv->hi3110_lock);
 790
 791         return 0;
 792
 793  out_free_wq:
 794         destroy_workqueue(priv->wq);
 795  out_free_irq:
 796         free_irq(spi->irq, priv);
 797         hi3110_hw_sleep(spi);
 798  out_close:
 799         hi3110_power_enable(priv->transceiver, 0);
 800         close_candev(net);
 801         mutex_unlock(&priv->hi3110_lock);
 802         return ret;
 803 }
 804
 805 static const struct net_device_ops hi3110_netdev_ops = {
 806         .ndo_open = hi3110_open,
 807         .ndo_stop = hi3110_stop,
 808         .ndo_start_xmit = hi3110_hard_start_xmit,
 809 };
 810
 811 static const struct of_device_id hi3110_of_match[] = {
 812         {
 813                 .compatible     = "holt,hi3110",
 814                 .data           = (void *)CAN_HI3110_HI3110,
 815         },
 816         { }
 817 };
 818 MODULE_DEVICE_TABLE(of, hi3110_of_match);
 819
 820 static const struct spi_device_id hi3110_id_table[] = {
 821         {
 822                 .name           = "hi3110",
 823                 .driver_data    = (kernel_ulong_t)CAN_HI3110_HI3110,
 824         },
 825         { }
 826 };
 827 MODULE_DEVICE_TABLE(spi, hi3110_id_table);
 828
 829 static int hi3110_can_probe(struct spi_device *spi)
 830 {
 831         const struct of_device_id *of_id = of_match_device(hi3110_of_match,
 832                                                            &spi->dev);
 833         struct net_device *net;
 834         struct hi3110_priv *priv;
 835         struct clk *clk;
 836         int freq, ret;
 837
 838         clk = devm_clk_get(&spi->dev, NULL);
 839         if (IS_ERR(clk)) {
 840                 dev_err(&spi->dev, "no CAN clock source defined\n");
 841                 return PTR_ERR(clk);
 842         }
 843         freq = clk_get_rate(clk);
 844
 845         /* Sanity check */
 846         if (freq > 40000000)
 847                 return -ERANGE;
 848
 849         /* Allocate can/net device */
 850         net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
 851         if (!net)
 852                 return -ENOMEM;
 853
 854         if (!IS_ERR(clk)) {
 855                 ret = clk_prepare_enable(clk);
 856                 if (ret)
 857                         goto out_free;
 858         }
 859
 860         net->netdev_ops = &hi3110_netdev_ops;
 861         net->flags |= IFF_ECHO;
 862
 863         priv = netdev_priv(net);
 864         priv->can.bittiming_const = &hi3110_bittiming_const;
 865         priv->can.do_set_mode = hi3110_do_set_mode;
 866         priv->can.do_get_berr_counter = hi3110_get_berr_counter;
 867         priv->can.clock.freq = freq / 2;
 868         priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 869                 CAN_CTRLMODE_LOOPBACK |
 870                 CAN_CTRLMODE_LISTENONLY |
 871                 CAN_CTRLMODE_BERR_REPORTING;
 872
 873         if (of_id)
 874                 priv->model = (enum hi3110_model)of_id->data;
 875         else
 876                 priv->model = spi_get_device_id(spi)->driver_data;
 877         priv->net = net;
 878         priv->clk = clk;
 879
 880         spi_set_drvdata(spi, priv);
 881
 882         /* Configure the SPI bus */
 883         spi->bits_per_word = 8;
 884         ret = spi_setup(spi);
 885         if (ret)
 886                 goto out_clk;
 887
 888         priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
 889         priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
 890         if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
 891             (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
 892                 ret = -EPROBE_DEFER;
 893                 goto out_clk;
 894         }
 895
 896         ret = hi3110_power_enable(priv->power, 1);
 897         if (ret)
 898                 goto out_clk;
 899
 900         priv->spi = spi;
 901         mutex_init(&priv->hi3110_lock);
 902
 903         priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
 904                                         GFP_KERNEL);
 905         if (!priv->spi_tx_buf) {
 906                 ret = -ENOMEM;
 907                 goto error_probe;
 908         }
 909         priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
 910                                         GFP_KERNEL);
 911
 912         if (!priv->spi_rx_buf) {
 913                 ret = -ENOMEM;
 914                 goto error_probe;
 915         }
 916
 917         SET_NETDEV_DEV(net, &spi->dev);
 918
 919         ret = hi3110_hw_probe(spi);
 920         if (ret) {
 921                 if (ret == -ENODEV)
 922                         dev_err(&spi->dev, "Cannot initialize %x. Wrong wiring?\n",
 923                                 priv->model);
 924                 goto error_probe;
 925         }
 926         hi3110_hw_sleep(spi);
 927
 928         ret = register_candev(net);
 929         if (ret)
 930                 goto error_probe;
 931
 932         devm_can_led_init(net);
 933         netdev_info(net, "%x successfully initialized.\n", priv->model);
 934
 935         return 0;
 936
 937  error_probe:
 938         hi3110_power_enable(priv->power, 0);
 939
 940  out_clk:
 941         if (!IS_ERR(clk))
 942                 clk_disable_unprepare(clk);
 943
 944  out_free:
 945         free_candev(net);
 946
 947         dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
 948         return ret;
 949 }
 950
 951 static int hi3110_can_remove(struct spi_device *spi)
 952 {
 953         struct hi3110_priv *priv = spi_get_drvdata(spi);
 954         struct net_device *net = priv->net;
 955
 956         unregister_candev(net);
 957
 958         hi3110_power_enable(priv->power, 0);
 959
 960         if (!IS_ERR(priv->clk))
 961                 clk_disable_unprepare(priv->clk);
 962
 963         free_candev(net);
 964
 965         return 0;
 966 }
 967
 968 static int __maybe_unused hi3110_can_suspend(struct device *dev)
 969 {
 970         struct spi_device *spi = to_spi_device(dev);
 971         struct hi3110_priv *priv = spi_get_drvdata(spi);
 972         struct net_device *net = priv->net;
 973
 974         priv->force_quit = 1;
 975         disable_irq(spi->irq);
 976
 977         /* Note: at this point neither IST nor workqueues are running.
 978          * open/stop cannot be called anyway so locking is not needed
 979          */
 980         if (netif_running(net)) {
 981                 netif_device_detach(net);
 982
 983                 hi3110_hw_sleep(spi);
 984                 hi3110_power_enable(priv->transceiver, 0);
 985                 priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
 986         } else {
 987                 priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
 988         }
 989
 990         if (!IS_ERR_OR_NULL(priv->power)) {
 991                 regulator_disable(priv->power);
 992                 priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
 993         }
 994
 995         return 0;
 996 }
 997
 998 static int __maybe_unused hi3110_can_resume(struct device *dev)
 999 {
1000         struct spi_device *spi = to_spi_device(dev);
1001         struct hi3110_priv *priv = spi_get_drvdata(spi);
1002
1003         if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
1004                 hi3110_power_enable(priv->power, 1);
1005
1006         if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
1007                 hi3110_power_enable(priv->transceiver, 1);
1008                 queue_work(priv->wq, &priv->restart_work);
1009         } else {
1010                 priv->after_suspend = 0;
1011         }
1012
1013         priv->force_quit = 0;
1014         enable_irq(spi->irq);
1015         return 0;
1016 }
1017
1018 static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);
1019
1020 static struct spi_driver hi3110_can_driver = {
1021         .driver = {
1022                 .name = DEVICE_NAME,
1023                 .of_match_table = hi3110_of_match,
1024                 .pm = &hi3110_can_pm_ops,
1025         },
1026         .id_table = hi3110_id_table,
1027         .probe = hi3110_can_probe,
1028         .remove = hi3110_can_remove,
1029 };
1030
1031 module_spi_driver(hi3110_can_driver);
1032
1033 MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
1034 MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
1035 MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
1036 MODULE_LICENSE("GPL v2");