linux/drivers/net/can/spi/hi311x.c
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   1/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface
   2 *
   3 * Copyright(C) Timesys Corporation 2016
   4 *
   5 * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver
   6 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
   7 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
   8 * Copyright 2006 Arcom Control Systems Ltd.
   9 *
  10 * Based on CAN bus driver for the CCAN controller written by
  11 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
  12 * - Simon Kallweit, intefo AG
  13 * Copyright 2007
  14 *
  15 * This program is free software; you can redistribute it and/or modify
  16 * it under the terms of the GNU General Public License version 2 as
  17 * published by the Free Software Foundation.
  18 */
  19
  20#include <linux/can/core.h>
  21#include <linux/can/dev.h>
  22#include <linux/can/led.h>
  23#include <linux/clk.h>
  24#include <linux/completion.h>
  25#include <linux/delay.h>
  26#include <linux/device.h>
  27#include <linux/dma-mapping.h>
  28#include <linux/freezer.h>
  29#include <linux/interrupt.h>
  30#include <linux/io.h>
  31#include <linux/kernel.h>
  32#include <linux/module.h>
  33#include <linux/netdevice.h>
  34#include <linux/of.h>
  35#include <linux/of_device.h>
  36#include <linux/platform_device.h>
  37#include <linux/regulator/consumer.h>
  38#include <linux/slab.h>
  39#include <linux/spi/spi.h>
  40#include <linux/uaccess.h>
  41
  42#define HI3110_MASTER_RESET 0x56
  43#define HI3110_READ_CTRL0 0xD2
  44#define HI3110_READ_CTRL1 0xD4
  45#define HI3110_READ_STATF 0xE2
  46#define HI3110_WRITE_CTRL0 0x14
  47#define HI3110_WRITE_CTRL1 0x16
  48#define HI3110_WRITE_INTE 0x1C
  49#define HI3110_WRITE_BTR0 0x18
  50#define HI3110_WRITE_BTR1 0x1A
  51#define HI3110_READ_BTR0 0xD6
  52#define HI3110_READ_BTR1 0xD8
  53#define HI3110_READ_INTF 0xDE
  54#define HI3110_READ_ERR 0xDC
  55#define HI3110_READ_FIFO_WOTIME 0x48
  56#define HI3110_WRITE_FIFO 0x12
  57#define HI3110_READ_MESSTAT 0xDA
  58#define HI3110_READ_REC 0xEA
  59#define HI3110_READ_TEC 0xEC
  60
  61#define HI3110_CTRL0_MODE_MASK (7 << 5)
  62#define HI3110_CTRL0_NORMAL_MODE (0 << 5)
  63#define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)
  64#define HI3110_CTRL0_MONITOR_MODE (2 << 5)
  65#define HI3110_CTRL0_SLEEP_MODE (3 << 5)
  66#define HI3110_CTRL0_INIT_MODE (4 << 5)
  67
  68#define HI3110_CTRL1_TXEN BIT(7)
  69
  70#define HI3110_INT_RXTMP BIT(7)
  71#define HI3110_INT_RXFIFO BIT(6)
  72#define HI3110_INT_TXCPLT BIT(5)
  73#define HI3110_INT_BUSERR BIT(4)
  74#define HI3110_INT_MCHG BIT(3)
  75#define HI3110_INT_WAKEUP BIT(2)
  76#define HI3110_INT_F1MESS BIT(1)
  77#define HI3110_INT_F0MESS BIT(0)
  78
  79#define HI3110_ERR_BUSOFF BIT(7)
  80#define HI3110_ERR_TXERRP BIT(6)
  81#define HI3110_ERR_RXERRP BIT(5)
  82#define HI3110_ERR_BITERR BIT(4)
  83#define HI3110_ERR_FRMERR BIT(3)
  84#define HI3110_ERR_CRCERR BIT(2)
  85#define HI3110_ERR_ACKERR BIT(1)
  86#define HI3110_ERR_STUFERR BIT(0)
  87#define HI3110_ERR_PROTOCOL_MASK (0x1F)
  88#define HI3110_ERR_PASSIVE_MASK (0x60)
  89
  90#define HI3110_STAT_RXFMTY BIT(1)
  91#define HI3110_STAT_BUSOFF BIT(2)
  92#define HI3110_STAT_ERRP BIT(3)
  93#define HI3110_STAT_ERRW BIT(4)
  94#define HI3110_STAT_TXMTY BIT(7)
  95
  96#define HI3110_BTR0_SJW_SHIFT 6
  97#define HI3110_BTR0_BRP_SHIFT 0
  98
  99#define HI3110_BTR1_SAMP_3PERBIT (1 << 7)
 100#define HI3110_BTR1_SAMP_1PERBIT (0 << 7)
 101#define HI3110_BTR1_TSEG2_SHIFT 4
 102#define HI3110_BTR1_TSEG1_SHIFT 0
 103
 104#define HI3110_FIFO_WOTIME_TAG_OFF 0
 105#define HI3110_FIFO_WOTIME_ID_OFF 1
 106#define HI3110_FIFO_WOTIME_DLC_OFF 5
 107#define HI3110_FIFO_WOTIME_DAT_OFF 6
 108
 109#define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)
 110#define HI3110_FIFO_WOTIME_ID_RTR BIT(0)
 111
 112#define HI3110_FIFO_TAG_OFF 0
 113#define HI3110_FIFO_ID_OFF 1
 114#define HI3110_FIFO_STD_DLC_OFF 3
 115#define HI3110_FIFO_STD_DATA_OFF 4
 116#define HI3110_FIFO_EXT_DLC_OFF 5
 117#define HI3110_FIFO_EXT_DATA_OFF 6
 118
 119#define HI3110_CAN_MAX_DATA_LEN 8
 120#define HI3110_RX_BUF_LEN 15
 121#define HI3110_TX_STD_BUF_LEN 12
 122#define HI3110_TX_EXT_BUF_LEN 14
 123#define HI3110_CAN_FRAME_MAX_BITS 128
 124#define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */
 125
 126#define HI3110_TX_ECHO_SKB_MAX 1
 127
 128#define HI3110_OST_DELAY_MS (10)
 129
 130#define DEVICE_NAME "hi3110"
 131
 132static int hi3110_enable_dma = 1; /* Enable SPI DMA. Default: 1 (On) */
 133module_param(hi3110_enable_dma, int, 0444);
 134MODULE_PARM_DESC(hi3110_enable_dma, "Enable SPI DMA. Default: 1 (On)");
 135
 136static const struct can_bittiming_const hi3110_bittiming_const = {
 137        .name = DEVICE_NAME,
 138        .tseg1_min = 2,
 139        .tseg1_max = 16,
 140        .tseg2_min = 2,
 141        .tseg2_max = 8,
 142        .sjw_max = 4,
 143        .brp_min = 1,
 144        .brp_max = 64,
 145        .brp_inc = 1,
 146};
 147
 148enum hi3110_model {
 149        CAN_HI3110_HI3110 = 0x3110,
 150};
 151
 152struct hi3110_priv {
 153        struct can_priv can;
 154        struct net_device *net;
 155        struct spi_device *spi;
 156        enum hi3110_model model;
 157
 158        struct mutex hi3110_lock; /* SPI device lock */
 159
 160        u8 *spi_tx_buf;
 161        u8 *spi_rx_buf;
 162        dma_addr_t spi_tx_dma;
 163        dma_addr_t spi_rx_dma;
 164
 165        struct sk_buff *tx_skb;
 166        int tx_len;
 167
 168        struct workqueue_struct *wq;
 169        struct work_struct tx_work;
 170        struct work_struct restart_work;
 171
 172        int force_quit;
 173        int after_suspend;
 174#define HI3110_AFTER_SUSPEND_UP 1
 175#define HI3110_AFTER_SUSPEND_DOWN 2
 176#define HI3110_AFTER_SUSPEND_POWER 4
 177#define HI3110_AFTER_SUSPEND_RESTART 8
 178        int restart_tx;
 179        struct regulator *power;
 180        struct regulator *transceiver;
 181        struct clk *clk;
 182};
 183
 184static void hi3110_clean(struct net_device *net)
 185{
 186        struct hi3110_priv *priv = netdev_priv(net);
 187
 188        if (priv->tx_skb || priv->tx_len)
 189                net->stats.tx_errors++;
 190        if (priv->tx_skb)
 191                dev_kfree_skb(priv->tx_skb);
 192        if (priv->tx_len)
 193                can_free_echo_skb(priv->net, 0);
 194        priv->tx_skb = NULL;
 195        priv->tx_len = 0;
 196}
 197
 198/* Note about handling of error return of hi3110_spi_trans: accessing
 199 * registers via SPI is not really different conceptually than using
 200 * normal I/O assembler instructions, although it's much more
 201 * complicated from a practical POV. So it's not advisable to always
 202 * check the return value of this function. Imagine that every
 203 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
 204 * error();", it would be a great mess (well there are some situation
 205 * when exception handling C++ like could be useful after all). So we
 206 * just check that transfers are OK at the beginning of our
 207 * conversation with the chip and to avoid doing really nasty things
 208 * (like injecting bogus packets in the network stack).
 209 */
 210static int hi3110_spi_trans(struct spi_device *spi, int len)
 211{
 212        struct hi3110_priv *priv = spi_get_drvdata(spi);
 213        struct spi_transfer t = {
 214                .tx_buf = priv->spi_tx_buf,
 215                .rx_buf = priv->spi_rx_buf,
 216                .len = len,
 217                .cs_change = 0,
 218        };
 219        struct spi_message m;
 220        int ret;
 221
 222        spi_message_init(&m);
 223
 224        if (hi3110_enable_dma) {
 225                t.tx_dma = priv->spi_tx_dma;
 226                t.rx_dma = priv->spi_rx_dma;
 227                m.is_dma_mapped = 1;
 228        }
 229
 230        spi_message_add_tail(&t, &m);
 231
 232        ret = spi_sync(spi, &m);
 233
 234        if (ret)
 235                dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
 236        return ret;
 237}
 238
 239static u8 hi3110_cmd(struct spi_device *spi, u8 command)
 240{
 241        struct hi3110_priv *priv = spi_get_drvdata(spi);
 242
 243        priv->spi_tx_buf[0] = command;
 244        dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);
 245
 246        return hi3110_spi_trans(spi, 1);
 247}
 248
 249static u8 hi3110_read(struct spi_device *spi, u8 command)
 250{
 251        struct hi3110_priv *priv = spi_get_drvdata(spi);
 252        u8 val = 0;
 253
 254        priv->spi_tx_buf[0] = command;
 255        hi3110_spi_trans(spi, 2);
 256        val = priv->spi_rx_buf[1];
 257
 258        return val;
 259}
 260
 261static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)
 262{
 263        struct hi3110_priv *priv = spi_get_drvdata(spi);
 264
 265        priv->spi_tx_buf[0] = reg;
 266        priv->spi_tx_buf[1] = val;
 267        hi3110_spi_trans(spi, 2);
 268}
 269
 270static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)
 271{
 272        struct hi3110_priv *priv = spi_get_drvdata(spi);
 273
 274        priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;
 275        memcpy(priv->spi_tx_buf + 1, buf, len);
 276        hi3110_spi_trans(spi, len + 1);
 277}
 278
 279static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)
 280{
 281        u8 buf[HI3110_TX_EXT_BUF_LEN];
 282
 283        buf[HI3110_FIFO_TAG_OFF] = 0;
 284
 285        if (frame->can_id & CAN_EFF_FLAG) {
 286                /* Extended frame */
 287                buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;
 288                buf[HI3110_FIFO_ID_OFF + 1] =
 289                        (((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |
 290                        HI3110_EFF_FLAGS |
 291                        (((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);
 292                buf[HI3110_FIFO_ID_OFF + 2] =
 293                        (frame->can_id & CAN_EFF_MASK) >> 7;
 294                buf[HI3110_FIFO_ID_OFF + 3] =
 295                        ((frame->can_id & CAN_EFF_MASK) << 1) |
 296                        ((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);
 297
 298                buf[HI3110_FIFO_EXT_DLC_OFF] = frame->can_dlc;
 299
 300                memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,
 301                       frame->data, frame->can_dlc);
 302
 303                hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -
 304                                   (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
 305        } else {
 306                /* Standard frame */
 307                buf[HI3110_FIFO_ID_OFF] =   (frame->can_id & CAN_SFF_MASK) >> 3;
 308                buf[HI3110_FIFO_ID_OFF + 1] =
 309                        ((frame->can_id & CAN_SFF_MASK) << 5) |
 310                        ((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);
 311
 312                buf[HI3110_FIFO_STD_DLC_OFF] = frame->can_dlc;
 313
 314                memcpy(buf + HI3110_FIFO_STD_DATA_OFF,
 315                       frame->data, frame->can_dlc);
 316
 317                hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -
 318                                   (HI3110_CAN_MAX_DATA_LEN - frame->can_dlc));
 319        }
 320}
 321
 322static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)
 323{
 324        struct hi3110_priv *priv = spi_get_drvdata(spi);
 325
 326        priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;
 327        hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);
 328        memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);
 329}
 330
 331static void hi3110_hw_rx(struct spi_device *spi)
 332{
 333        struct hi3110_priv *priv = spi_get_drvdata(spi);
 334        struct sk_buff *skb;
 335        struct can_frame *frame;
 336        u8 buf[HI3110_RX_BUF_LEN - 1];
 337
 338        skb = alloc_can_skb(priv->net, &frame);
 339        if (!skb) {
 340                priv->net->stats.rx_dropped++;
 341                return;
 342        }
 343
 344        hi3110_hw_rx_frame(spi, buf);
 345        if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {
 346                /* IDE is recessive (1), indicating extended 29-bit frame */
 347                frame->can_id = CAN_EFF_FLAG;
 348                frame->can_id |=
 349                        (buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |
 350                        (((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |
 351                        ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |
 352                        (buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |
 353                        (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);
 354        } else {
 355                /* IDE is dominant (0), frame indicating standard 11-bit */
 356                frame->can_id =
 357                        (buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |
 358                        ((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);
 359        }
 360
 361        /* Data length */
 362        frame->can_dlc = get_can_dlc(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);
 363
 364        if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR)
 365                frame->can_id |= CAN_RTR_FLAG;
 366        else
 367                memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,
 368                       frame->can_dlc);
 369
 370        priv->net->stats.rx_packets++;
 371        priv->net->stats.rx_bytes += frame->can_dlc;
 372
 373        can_led_event(priv->net, CAN_LED_EVENT_RX);
 374
 375        netif_rx_ni(skb);
 376}
 377
 378static void hi3110_hw_sleep(struct spi_device *spi)
 379{
 380        hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);
 381}
 382
 383static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,
 384                                          struct net_device *net)
 385{
 386        struct hi3110_priv *priv = netdev_priv(net);
 387        struct spi_device *spi = priv->spi;
 388
 389        if (priv->tx_skb || priv->tx_len) {
 390                dev_err(&spi->dev, "hard_xmit called while tx busy\n");
 391                return NETDEV_TX_BUSY;
 392        }
 393
 394        if (can_dropped_invalid_skb(net, skb))
 395                return NETDEV_TX_OK;
 396
 397        netif_stop_queue(net);
 398        priv->tx_skb = skb;
 399        queue_work(priv->wq, &priv->tx_work);
 400
 401        return NETDEV_TX_OK;
 402}
 403
 404static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)
 405{
 406        struct hi3110_priv *priv = netdev_priv(net);
 407
 408        switch (mode) {
 409        case CAN_MODE_START:
 410                hi3110_clean(net);
 411                /* We have to delay work since SPI I/O may sleep */
 412                priv->can.state = CAN_STATE_ERROR_ACTIVE;
 413                priv->restart_tx = 1;
 414                if (priv->can.restart_ms == 0)
 415                        priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;
 416                queue_work(priv->wq, &priv->restart_work);
 417                break;
 418        default:
 419                return -EOPNOTSUPP;
 420        }
 421
 422        return 0;
 423}
 424
 425static int hi3110_get_berr_counter(const struct net_device *net,
 426                                   struct can_berr_counter *bec)
 427{
 428        struct hi3110_priv *priv = netdev_priv(net);
 429        struct spi_device *spi = priv->spi;
 430
 431        mutex_lock(&priv->hi3110_lock);
 432        bec->txerr = hi3110_read(spi, HI3110_READ_TEC);
 433        bec->rxerr = hi3110_read(spi, HI3110_READ_REC);
 434        mutex_unlock(&priv->hi3110_lock);
 435
 436        return 0;
 437}
 438
 439static int hi3110_set_normal_mode(struct spi_device *spi)
 440{
 441        struct hi3110_priv *priv = spi_get_drvdata(spi);
 442        u8 reg = 0;
 443
 444        hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |
 445                     HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);
 446
 447        /* Enable TX */
 448        hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);
 449
 450        if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 451                reg = HI3110_CTRL0_LOOPBACK_MODE;
 452        else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 453                reg = HI3110_CTRL0_MONITOR_MODE;
 454        else
 455                reg = HI3110_CTRL0_NORMAL_MODE;
 456
 457        hi3110_write(spi, HI3110_WRITE_CTRL0, reg);
 458
 459        /* Wait for the device to enter the mode */
 460        mdelay(HI3110_OST_DELAY_MS);
 461        reg = hi3110_read(spi, HI3110_READ_CTRL0);
 462        if ((reg & HI3110_CTRL0_MODE_MASK) != reg)
 463                return -EBUSY;
 464
 465        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 466        return 0;
 467}
 468
 469static int hi3110_do_set_bittiming(struct net_device *net)
 470{
 471        struct hi3110_priv *priv = netdev_priv(net);
 472        struct can_bittiming *bt = &priv->can.bittiming;
 473        struct spi_device *spi = priv->spi;
 474
 475        hi3110_write(spi, HI3110_WRITE_BTR0,
 476                     ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |
 477                     ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));
 478
 479        hi3110_write(spi, HI3110_WRITE_BTR1,
 480                     (priv->can.ctrlmode &
 481                      CAN_CTRLMODE_3_SAMPLES ?
 482                      HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |
 483                     ((bt->phase_seg1 + bt->prop_seg - 1)
 484                      << HI3110_BTR1_TSEG1_SHIFT) |
 485                     ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));
 486
 487        dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",
 488                hi3110_read(spi, HI3110_READ_BTR0),
 489                hi3110_read(spi, HI3110_READ_BTR1));
 490
 491        return 0;
 492}
 493
 494static int hi3110_setup(struct net_device *net)
 495{
 496        hi3110_do_set_bittiming(net);
 497        return 0;
 498}
 499
 500static int hi3110_hw_reset(struct spi_device *spi)
 501{
 502        u8 reg;
 503        int ret;
 504
 505        /* Wait for oscillator startup timer after power up */
 506        mdelay(HI3110_OST_DELAY_MS);
 507
 508        ret = hi3110_cmd(spi, HI3110_MASTER_RESET);
 509        if (ret)
 510                return ret;
 511
 512        /* Wait for oscillator startup timer after reset */
 513        mdelay(HI3110_OST_DELAY_MS);
 514
 515        reg = hi3110_read(spi, HI3110_READ_CTRL0);
 516        if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)
 517                return -ENODEV;
 518
 519        /* As per the datasheet it appears the error flags are
 520         * not cleared on reset. Explicitly clear them by performing a read
 521         */
 522        hi3110_read(spi, HI3110_READ_ERR);
 523
 524        return 0;
 525}
 526
 527static int hi3110_hw_probe(struct spi_device *spi)
 528{
 529        u8 statf;
 530
 531        hi3110_hw_reset(spi);
 532
 533        /* Confirm correct operation by checking against reset values
 534         * in datasheet
 535         */
 536        statf = hi3110_read(spi, HI3110_READ_STATF);
 537
 538        dev_dbg(&spi->dev, "statf: %02X\n", statf);
 539
 540        if (statf != 0x82)
 541                return -ENODEV;
 542
 543        return 0;
 544}
 545
 546static int hi3110_power_enable(struct regulator *reg, int enable)
 547{
 548        if (IS_ERR_OR_NULL(reg))
 549                return 0;
 550
 551        if (enable)
 552                return regulator_enable(reg);
 553        else
 554                return regulator_disable(reg);
 555}
 556
 557static int hi3110_stop(struct net_device *net)
 558{
 559        struct hi3110_priv *priv = netdev_priv(net);
 560        struct spi_device *spi = priv->spi;
 561
 562        close_candev(net);
 563
 564        priv->force_quit = 1;
 565        free_irq(spi->irq, priv);
 566        destroy_workqueue(priv->wq);
 567        priv->wq = NULL;
 568
 569        mutex_lock(&priv->hi3110_lock);
 570
 571        /* Disable transmit, interrupts and clear flags */
 572        hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);
 573        hi3110_write(spi, HI3110_WRITE_INTE, 0x0);
 574        hi3110_read(spi, HI3110_READ_INTF);
 575
 576        hi3110_clean(net);
 577
 578        hi3110_hw_sleep(spi);
 579
 580        hi3110_power_enable(priv->transceiver, 0);
 581
 582        priv->can.state = CAN_STATE_STOPPED;
 583
 584        mutex_unlock(&priv->hi3110_lock);
 585
 586        can_led_event(net, CAN_LED_EVENT_STOP);
 587
 588        return 0;
 589}
 590
 591static void hi3110_tx_work_handler(struct work_struct *ws)
 592{
 593        struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
 594                                                tx_work);
 595        struct spi_device *spi = priv->spi;
 596        struct net_device *net = priv->net;
 597        struct can_frame *frame;
 598
 599        mutex_lock(&priv->hi3110_lock);
 600        if (priv->tx_skb) {
 601                if (priv->can.state == CAN_STATE_BUS_OFF) {
 602                        hi3110_clean(net);
 603                } else {
 604                        frame = (struct can_frame *)priv->tx_skb->data;
 605                        hi3110_hw_tx(spi, frame);
 606                        priv->tx_len = 1 + frame->can_dlc;
 607                        can_put_echo_skb(priv->tx_skb, net, 0);
 608                        priv->tx_skb = NULL;
 609                }
 610        }
 611        mutex_unlock(&priv->hi3110_lock);
 612}
 613
 614static void hi3110_restart_work_handler(struct work_struct *ws)
 615{
 616        struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,
 617                                                restart_work);
 618        struct spi_device *spi = priv->spi;
 619        struct net_device *net = priv->net;
 620
 621        mutex_lock(&priv->hi3110_lock);
 622        if (priv->after_suspend) {
 623                hi3110_hw_reset(spi);
 624                hi3110_setup(net);
 625                if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {
 626                        hi3110_set_normal_mode(spi);
 627                } else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
 628                        netif_device_attach(net);
 629                        hi3110_clean(net);
 630                        hi3110_set_normal_mode(spi);
 631                        netif_wake_queue(net);
 632                } else {
 633                        hi3110_hw_sleep(spi);
 634                }
 635                priv->after_suspend = 0;
 636                priv->force_quit = 0;
 637        }
 638
 639        if (priv->restart_tx) {
 640                priv->restart_tx = 0;
 641                hi3110_hw_reset(spi);
 642                hi3110_setup(net);
 643                hi3110_clean(net);
 644                hi3110_set_normal_mode(spi);
 645                netif_wake_queue(net);
 646        }
 647        mutex_unlock(&priv->hi3110_lock);
 648}
 649
 650static irqreturn_t hi3110_can_ist(int irq, void *dev_id)
 651{
 652        struct hi3110_priv *priv = dev_id;
 653        struct spi_device *spi = priv->spi;
 654        struct net_device *net = priv->net;
 655
 656        mutex_lock(&priv->hi3110_lock);
 657
 658        while (!priv->force_quit) {
 659                enum can_state new_state;
 660                u8 intf, eflag, statf;
 661
 662                while (!(HI3110_STAT_RXFMTY &
 663                         (statf = hi3110_read(spi, HI3110_READ_STATF)))) {
 664                        hi3110_hw_rx(spi);
 665                }
 666
 667                intf = hi3110_read(spi, HI3110_READ_INTF);
 668                eflag = hi3110_read(spi, HI3110_READ_ERR);
 669                /* Update can state */
 670                if (eflag & HI3110_ERR_BUSOFF)
 671                        new_state = CAN_STATE_BUS_OFF;
 672                else if (eflag & HI3110_ERR_PASSIVE_MASK)
 673                        new_state = CAN_STATE_ERROR_PASSIVE;
 674                else if (statf & HI3110_STAT_ERRW)
 675                        new_state = CAN_STATE_ERROR_WARNING;
 676                else
 677                        new_state = CAN_STATE_ERROR_ACTIVE;
 678
 679                if (new_state != priv->can.state) {
 680                        struct can_frame *cf;
 681                        struct sk_buff *skb;
 682                        enum can_state rx_state, tx_state;
 683                        u8 rxerr, txerr;
 684
 685                        skb = alloc_can_err_skb(net, &cf);
 686                        if (!skb)
 687                                break;
 688
 689                        txerr = hi3110_read(spi, HI3110_READ_TEC);
 690                        rxerr = hi3110_read(spi, HI3110_READ_REC);
 691                        cf->data[6] = txerr;
 692                        cf->data[7] = rxerr;
 693                        tx_state = txerr >= rxerr ? new_state : 0;
 694                        rx_state = txerr <= rxerr ? new_state : 0;
 695                        can_change_state(net, cf, tx_state, rx_state);
 696                        netif_rx_ni(skb);
 697
 698                        if (new_state == CAN_STATE_BUS_OFF) {
 699                                can_bus_off(net);
 700                                if (priv->can.restart_ms == 0) {
 701                                        priv->force_quit = 1;
 702                                        hi3110_hw_sleep(spi);
 703                                        break;
 704                                }
 705                        }
 706                }
 707
 708                /* Update bus errors */
 709                if ((intf & HI3110_INT_BUSERR) &&
 710                    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {
 711                        struct can_frame *cf;
 712                        struct sk_buff *skb;
 713
 714                        /* Check for protocol errors */
 715                        if (eflag & HI3110_ERR_PROTOCOL_MASK) {
 716                                skb = alloc_can_err_skb(net, &cf);
 717                                if (!skb)
 718                                        break;
 719
 720                                cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 721                                priv->can.can_stats.bus_error++;
 722                                priv->net->stats.rx_errors++;
 723                                if (eflag & HI3110_ERR_BITERR)
 724                                        cf->data[2] |= CAN_ERR_PROT_BIT;
 725                                else if (eflag & HI3110_ERR_FRMERR)
 726                                        cf->data[2] |= CAN_ERR_PROT_FORM;
 727                                else if (eflag & HI3110_ERR_STUFERR)
 728                                        cf->data[2] |= CAN_ERR_PROT_STUFF;
 729                                else if (eflag & HI3110_ERR_CRCERR)
 730                                        cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;
 731                                else if (eflag & HI3110_ERR_ACKERR)
 732                                        cf->data[3] |= CAN_ERR_PROT_LOC_ACK;
 733
 734                                cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);
 735                                cf->data[7] = hi3110_read(spi, HI3110_READ_REC);
 736                                netdev_dbg(priv->net, "Bus Error\n");
 737                                netif_rx_ni(skb);
 738                        }
 739                }
 740
 741                if (priv->tx_len && statf & HI3110_STAT_TXMTY) {
 742                        net->stats.tx_packets++;
 743                        net->stats.tx_bytes += priv->tx_len - 1;
 744                        can_led_event(net, CAN_LED_EVENT_TX);
 745                        if (priv->tx_len) {
 746                                can_get_echo_skb(net, 0);
 747                                priv->tx_len = 0;
 748                        }
 749                        netif_wake_queue(net);
 750                }
 751
 752                if (intf == 0)
 753                        break;
 754        }
 755        mutex_unlock(&priv->hi3110_lock);
 756        return IRQ_HANDLED;
 757}
 758
 759static int hi3110_open(struct net_device *net)
 760{
 761        struct hi3110_priv *priv = netdev_priv(net);
 762        struct spi_device *spi = priv->spi;
 763        unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_RISING;
 764        int ret;
 765
 766        ret = open_candev(net);
 767        if (ret)
 768                return ret;
 769
 770        mutex_lock(&priv->hi3110_lock);
 771        hi3110_power_enable(priv->transceiver, 1);
 772
 773        priv->force_quit = 0;
 774        priv->tx_skb = NULL;
 775        priv->tx_len = 0;
 776
 777        ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,
 778                                   flags, DEVICE_NAME, priv);
 779        if (ret) {
 780                dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
 781                goto out_close;
 782        }
 783
 784        priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
 785                                   0);
 786        if (!priv->wq) {
 787                ret = -ENOMEM;
 788                goto out_free_irq;
 789        }
 790        INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);
 791        INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);
 792
 793        ret = hi3110_hw_reset(spi);
 794        if (ret)
 795                goto out_free_wq;
 796
 797        ret = hi3110_setup(net);
 798        if (ret)
 799                goto out_free_wq;
 800
 801        ret = hi3110_set_normal_mode(spi);
 802        if (ret)
 803                goto out_free_wq;
 804
 805        can_led_event(net, CAN_LED_EVENT_OPEN);
 806        netif_wake_queue(net);
 807        mutex_unlock(&priv->hi3110_lock);
 808
 809        return 0;
 810
 811 out_free_wq:
 812        destroy_workqueue(priv->wq);
 813 out_free_irq:
 814        free_irq(spi->irq, priv);
 815        hi3110_hw_sleep(spi);
 816 out_close:
 817        hi3110_power_enable(priv->transceiver, 0);
 818        close_candev(net);
 819        mutex_unlock(&priv->hi3110_lock);
 820        return ret;
 821}
 822
 823static const struct net_device_ops hi3110_netdev_ops = {
 824        .ndo_open = hi3110_open,
 825        .ndo_stop = hi3110_stop,
 826        .ndo_start_xmit = hi3110_hard_start_xmit,
 827};
 828
 829static const struct of_device_id hi3110_of_match[] = {
 830        {
 831                .compatible     = "holt,hi3110",
 832                .data           = (void *)CAN_HI3110_HI3110,
 833        },
 834        { }
 835};
 836MODULE_DEVICE_TABLE(of, hi3110_of_match);
 837
 838static const struct spi_device_id hi3110_id_table[] = {
 839        {
 840                .name           = "hi3110",
 841                .driver_data    = (kernel_ulong_t)CAN_HI3110_HI3110,
 842        },
 843        { }
 844};
 845MODULE_DEVICE_TABLE(spi, hi3110_id_table);
 846
 847static int hi3110_can_probe(struct spi_device *spi)
 848{
 849        const struct of_device_id *of_id = of_match_device(hi3110_of_match,
 850                                                           &spi->dev);
 851        struct net_device *net;
 852        struct hi3110_priv *priv;
 853        struct clk *clk;
 854        int freq, ret;
 855
 856        clk = devm_clk_get(&spi->dev, NULL);
 857        if (IS_ERR(clk)) {
 858                dev_err(&spi->dev, "no CAN clock source defined\n");
 859                return PTR_ERR(clk);
 860        }
 861        freq = clk_get_rate(clk);
 862
 863        /* Sanity check */
 864        if (freq > 40000000)
 865                return -ERANGE;
 866
 867        /* Allocate can/net device */
 868        net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);
 869        if (!net)
 870                return -ENOMEM;
 871
 872        if (!IS_ERR(clk)) {
 873                ret = clk_prepare_enable(clk);
 874                if (ret)
 875                        goto out_free;
 876        }
 877
 878        net->netdev_ops = &hi3110_netdev_ops;
 879        net->flags |= IFF_ECHO;
 880
 881        priv = netdev_priv(net);
 882        priv->can.bittiming_const = &hi3110_bittiming_const;
 883        priv->can.do_set_mode = hi3110_do_set_mode;
 884        priv->can.do_get_berr_counter = hi3110_get_berr_counter;
 885        priv->can.clock.freq = freq / 2;
 886        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
 887                CAN_CTRLMODE_LOOPBACK |
 888                CAN_CTRLMODE_LISTENONLY |
 889                CAN_CTRLMODE_BERR_REPORTING;
 890
 891        if (of_id)
 892                priv->model = (enum hi3110_model)of_id->data;
 893        else
 894                priv->model = spi_get_device_id(spi)->driver_data;
 895        priv->net = net;
 896        priv->clk = clk;
 897
 898        spi_set_drvdata(spi, priv);
 899
 900        /* Configure the SPI bus */
 901        spi->bits_per_word = 8;
 902        ret = spi_setup(spi);
 903        if (ret)
 904                goto out_clk;
 905
 906        priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
 907        priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
 908        if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
 909            (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
 910                ret = -EPROBE_DEFER;
 911                goto out_clk;
 912        }
 913
 914        ret = hi3110_power_enable(priv->power, 1);
 915        if (ret)
 916                goto out_clk;
 917
 918        priv->spi = spi;
 919        mutex_init(&priv->hi3110_lock);
 920
 921        /* If requested, allocate DMA buffers */
 922        if (hi3110_enable_dma) {
 923                spi->dev.coherent_dma_mask = ~0;
 924
 925                /* Minimum coherent DMA allocation is PAGE_SIZE, so allocate
 926                 * that much and share it between Tx and Rx DMA buffers.
 927                 */
 928                priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
 929                                                       PAGE_SIZE,
 930                                                       &priv->spi_tx_dma,
 931                                                       GFP_DMA);
 932
 933                if (priv->spi_tx_buf) {
 934                        priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
 935                        priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
 936                                                        (PAGE_SIZE / 2));
 937                } else {
 938                        /* Fall back to non-DMA */
 939                        hi3110_enable_dma = 0;
 940                }
 941        }
 942
 943        /* Allocate non-DMA buffers */
 944        if (!hi3110_enable_dma) {
 945                priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
 946                                                GFP_KERNEL);
 947                if (!priv->spi_tx_buf) {
 948                        ret = -ENOMEM;
 949                        goto error_probe;
 950                }
 951                priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,
 952                                                GFP_KERNEL);
 953
 954                if (!priv->spi_rx_buf) {
 955                        ret = -ENOMEM;
 956                        goto error_probe;
 957                }
 958        }
 959
 960        SET_NETDEV_DEV(net, &spi->dev);
 961
 962        ret = hi3110_hw_probe(spi);
 963        if (ret) {
 964                if (ret == -ENODEV)
 965                        dev_err(&spi->dev, "Cannot initialize %x. Wrong wiring?\n",
 966                                priv->model);
 967                goto error_probe;
 968        }
 969        hi3110_hw_sleep(spi);
 970
 971        ret = register_candev(net);
 972        if (ret)
 973                goto error_probe;
 974
 975        devm_can_led_init(net);
 976        netdev_info(net, "%x successfully initialized.\n", priv->model);
 977
 978        return 0;
 979
 980 error_probe:
 981        hi3110_power_enable(priv->power, 0);
 982
 983 out_clk:
 984        if (!IS_ERR(clk))
 985                clk_disable_unprepare(clk);
 986
 987 out_free:
 988        free_candev(net);
 989
 990        dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
 991        return ret;
 992}
 993
 994static int hi3110_can_remove(struct spi_device *spi)
 995{
 996        struct hi3110_priv *priv = spi_get_drvdata(spi);
 997        struct net_device *net = priv->net;
 998
 999        unregister_candev(net);
1000
1001        hi3110_power_enable(priv->power, 0);
1002
1003        if (!IS_ERR(priv->clk))
1004                clk_disable_unprepare(priv->clk);
1005
1006        free_candev(net);
1007
1008        return 0;
1009}
1010
1011static int __maybe_unused hi3110_can_suspend(struct device *dev)
1012{
1013        struct spi_device *spi = to_spi_device(dev);
1014        struct hi3110_priv *priv = spi_get_drvdata(spi);
1015        struct net_device *net = priv->net;
1016
1017        priv->force_quit = 1;
1018        disable_irq(spi->irq);
1019
1020        /* Note: at this point neither IST nor workqueues are running.
1021         * open/stop cannot be called anyway so locking is not needed
1022         */
1023        if (netif_running(net)) {
1024                netif_device_detach(net);
1025
1026                hi3110_hw_sleep(spi);
1027                hi3110_power_enable(priv->transceiver, 0);
1028                priv->after_suspend = HI3110_AFTER_SUSPEND_UP;
1029        } else {
1030                priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;
1031        }
1032
1033        if (!IS_ERR_OR_NULL(priv->power)) {
1034                regulator_disable(priv->power);
1035                priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;
1036        }
1037
1038        return 0;
1039}
1040
1041static int __maybe_unused hi3110_can_resume(struct device *dev)
1042{
1043        struct spi_device *spi = to_spi_device(dev);
1044        struct hi3110_priv *priv = spi_get_drvdata(spi);
1045
1046        if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)
1047                hi3110_power_enable(priv->power, 1);
1048
1049        if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {
1050                hi3110_power_enable(priv->transceiver, 1);
1051                queue_work(priv->wq, &priv->restart_work);
1052        } else {
1053                priv->after_suspend = 0;
1054        }
1055
1056        priv->force_quit = 0;
1057        enable_irq(spi->irq);
1058        return 0;
1059}
1060
1061static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);
1062
1063static struct spi_driver hi3110_can_driver = {
1064        .driver = {
1065                .name = DEVICE_NAME,
1066                .of_match_table = hi3110_of_match,
1067                .pm = &hi3110_can_pm_ops,
1068        },
1069        .id_table = hi3110_id_table,
1070        .probe = hi3110_can_probe,
1071        .remove = hi3110_can_remove,
1072};
1073
1074module_spi_driver(hi3110_can_driver);
1075
1076MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");
1077MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");
1078MODULE_DESCRIPTION("Holt HI-3110 CAN driver");
1079MODULE_LICENSE("GPL v2");
1080