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