linux/drivers/net/can/m_can/m_can.c
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   1/*
   2 * CAN bus driver for Bosch M_CAN controller
   3 *
   4 * Copyright (C) 2014 Freescale Semiconductor, Inc.
   5 *      Dong Aisheng <b29396@freescale.com>
   6 *
   7 * Bosch M_CAN user manual can be obtained from:
   8 * http://www.bosch-semiconductors.de/media/pdf_1/ipmodules_1/m_can/
   9 * mcan_users_manual_v302.pdf
  10 *
  11 * This file is licensed under the terms of the GNU General Public
  12 * License version 2. This program is licensed "as is" without any
  13 * warranty of any kind, whether express or implied.
  14 */
  15
  16#include <linux/clk.h>
  17#include <linux/delay.h>
  18#include <linux/interrupt.h>
  19#include <linux/io.h>
  20#include <linux/kernel.h>
  21#include <linux/module.h>
  22#include <linux/netdevice.h>
  23#include <linux/of.h>
  24#include <linux/of_device.h>
  25#include <linux/platform_device.h>
  26
  27#include <linux/can/dev.h>
  28
  29/* napi related */
  30#define M_CAN_NAPI_WEIGHT       64
  31
  32/* message ram configuration data length */
  33#define MRAM_CFG_LEN    8
  34
  35/* registers definition */
  36enum m_can_reg {
  37        M_CAN_CREL      = 0x0,
  38        M_CAN_ENDN      = 0x4,
  39        M_CAN_CUST      = 0x8,
  40        M_CAN_FBTP      = 0xc,
  41        M_CAN_TEST      = 0x10,
  42        M_CAN_RWD       = 0x14,
  43        M_CAN_CCCR      = 0x18,
  44        M_CAN_BTP       = 0x1c,
  45        M_CAN_TSCC      = 0x20,
  46        M_CAN_TSCV      = 0x24,
  47        M_CAN_TOCC      = 0x28,
  48        M_CAN_TOCV      = 0x2c,
  49        M_CAN_ECR       = 0x40,
  50        M_CAN_PSR       = 0x44,
  51        M_CAN_IR        = 0x50,
  52        M_CAN_IE        = 0x54,
  53        M_CAN_ILS       = 0x58,
  54        M_CAN_ILE       = 0x5c,
  55        M_CAN_GFC       = 0x80,
  56        M_CAN_SIDFC     = 0x84,
  57        M_CAN_XIDFC     = 0x88,
  58        M_CAN_XIDAM     = 0x90,
  59        M_CAN_HPMS      = 0x94,
  60        M_CAN_NDAT1     = 0x98,
  61        M_CAN_NDAT2     = 0x9c,
  62        M_CAN_RXF0C     = 0xa0,
  63        M_CAN_RXF0S     = 0xa4,
  64        M_CAN_RXF0A     = 0xa8,
  65        M_CAN_RXBC      = 0xac,
  66        M_CAN_RXF1C     = 0xb0,
  67        M_CAN_RXF1S     = 0xb4,
  68        M_CAN_RXF1A     = 0xb8,
  69        M_CAN_RXESC     = 0xbc,
  70        M_CAN_TXBC      = 0xc0,
  71        M_CAN_TXFQS     = 0xc4,
  72        M_CAN_TXESC     = 0xc8,
  73        M_CAN_TXBRP     = 0xcc,
  74        M_CAN_TXBAR     = 0xd0,
  75        M_CAN_TXBCR     = 0xd4,
  76        M_CAN_TXBTO     = 0xd8,
  77        M_CAN_TXBCF     = 0xdc,
  78        M_CAN_TXBTIE    = 0xe0,
  79        M_CAN_TXBCIE    = 0xe4,
  80        M_CAN_TXEFC     = 0xf0,
  81        M_CAN_TXEFS     = 0xf4,
  82        M_CAN_TXEFA     = 0xf8,
  83};
  84
  85/* m_can lec values */
  86enum m_can_lec_type {
  87        LEC_NO_ERROR = 0,
  88        LEC_STUFF_ERROR,
  89        LEC_FORM_ERROR,
  90        LEC_ACK_ERROR,
  91        LEC_BIT1_ERROR,
  92        LEC_BIT0_ERROR,
  93        LEC_CRC_ERROR,
  94        LEC_UNUSED,
  95};
  96
  97enum m_can_mram_cfg {
  98        MRAM_SIDF = 0,
  99        MRAM_XIDF,
 100        MRAM_RXF0,
 101        MRAM_RXF1,
 102        MRAM_RXB,
 103        MRAM_TXE,
 104        MRAM_TXB,
 105        MRAM_CFG_NUM,
 106};
 107
 108/* Fast Bit Timing & Prescaler Register (FBTP) */
 109#define FBTR_FBRP_MASK          0x1f
 110#define FBTR_FBRP_SHIFT         16
 111#define FBTR_FTSEG1_SHIFT       8
 112#define FBTR_FTSEG1_MASK        (0xf << FBTR_FTSEG1_SHIFT)
 113#define FBTR_FTSEG2_SHIFT       4
 114#define FBTR_FTSEG2_MASK        (0x7 << FBTR_FTSEG2_SHIFT)
 115#define FBTR_FSJW_SHIFT         0
 116#define FBTR_FSJW_MASK          0x3
 117
 118/* Test Register (TEST) */
 119#define TEST_LBCK       BIT(4)
 120
 121/* CC Control Register(CCCR) */
 122#define CCCR_TEST               BIT(7)
 123#define CCCR_CMR_MASK           0x3
 124#define CCCR_CMR_SHIFT          10
 125#define CCCR_CMR_CANFD          0x1
 126#define CCCR_CMR_CANFD_BRS      0x2
 127#define CCCR_CMR_CAN            0x3
 128#define CCCR_CME_MASK           0x3
 129#define CCCR_CME_SHIFT          8
 130#define CCCR_CME_CAN            0
 131#define CCCR_CME_CANFD          0x1
 132#define CCCR_CME_CANFD_BRS      0x2
 133#define CCCR_TEST               BIT(7)
 134#define CCCR_MON                BIT(5)
 135#define CCCR_CCE                BIT(1)
 136#define CCCR_INIT               BIT(0)
 137#define CCCR_CANFD              0x10
 138
 139/* Bit Timing & Prescaler Register (BTP) */
 140#define BTR_BRP_MASK            0x3ff
 141#define BTR_BRP_SHIFT           16
 142#define BTR_TSEG1_SHIFT         8
 143#define BTR_TSEG1_MASK          (0x3f << BTR_TSEG1_SHIFT)
 144#define BTR_TSEG2_SHIFT         4
 145#define BTR_TSEG2_MASK          (0xf << BTR_TSEG2_SHIFT)
 146#define BTR_SJW_SHIFT           0
 147#define BTR_SJW_MASK            0xf
 148
 149/* Error Counter Register(ECR) */
 150#define ECR_RP                  BIT(15)
 151#define ECR_REC_SHIFT           8
 152#define ECR_REC_MASK            (0x7f << ECR_REC_SHIFT)
 153#define ECR_TEC_SHIFT           0
 154#define ECR_TEC_MASK            0xff
 155
 156/* Protocol Status Register(PSR) */
 157#define PSR_BO          BIT(7)
 158#define PSR_EW          BIT(6)
 159#define PSR_EP          BIT(5)
 160#define PSR_LEC_MASK    0x7
 161
 162/* Interrupt Register(IR) */
 163#define IR_ALL_INT      0xffffffff
 164#define IR_STE          BIT(31)
 165#define IR_FOE          BIT(30)
 166#define IR_ACKE         BIT(29)
 167#define IR_BE           BIT(28)
 168#define IR_CRCE         BIT(27)
 169#define IR_WDI          BIT(26)
 170#define IR_BO           BIT(25)
 171#define IR_EW           BIT(24)
 172#define IR_EP           BIT(23)
 173#define IR_ELO          BIT(22)
 174#define IR_BEU          BIT(21)
 175#define IR_BEC          BIT(20)
 176#define IR_DRX          BIT(19)
 177#define IR_TOO          BIT(18)
 178#define IR_MRAF         BIT(17)
 179#define IR_TSW          BIT(16)
 180#define IR_TEFL         BIT(15)
 181#define IR_TEFF         BIT(14)
 182#define IR_TEFW         BIT(13)
 183#define IR_TEFN         BIT(12)
 184#define IR_TFE          BIT(11)
 185#define IR_TCF          BIT(10)
 186#define IR_TC           BIT(9)
 187#define IR_HPM          BIT(8)
 188#define IR_RF1L         BIT(7)
 189#define IR_RF1F         BIT(6)
 190#define IR_RF1W         BIT(5)
 191#define IR_RF1N         BIT(4)
 192#define IR_RF0L         BIT(3)
 193#define IR_RF0F         BIT(2)
 194#define IR_RF0W         BIT(1)
 195#define IR_RF0N         BIT(0)
 196#define IR_ERR_STATE    (IR_BO | IR_EW | IR_EP)
 197#define IR_ERR_LEC      (IR_STE | IR_FOE | IR_ACKE | IR_BE | IR_CRCE)
 198#define IR_ERR_BUS      (IR_ERR_LEC | IR_WDI | IR_ELO | IR_BEU | \
 199                         IR_BEC | IR_TOO | IR_MRAF | IR_TSW | IR_TEFL | \
 200                         IR_RF1L | IR_RF0L)
 201#define IR_ERR_ALL      (IR_ERR_STATE | IR_ERR_BUS)
 202
 203/* Interrupt Line Select (ILS) */
 204#define ILS_ALL_INT0    0x0
 205#define ILS_ALL_INT1    0xFFFFFFFF
 206
 207/* Interrupt Line Enable (ILE) */
 208#define ILE_EINT0       BIT(0)
 209#define ILE_EINT1       BIT(1)
 210
 211/* Rx FIFO 0/1 Configuration (RXF0C/RXF1C) */
 212#define RXFC_FWM_OFF    24
 213#define RXFC_FWM_MASK   0x7f
 214#define RXFC_FWM_1      (1 << RXFC_FWM_OFF)
 215#define RXFC_FS_OFF     16
 216#define RXFC_FS_MASK    0x7f
 217
 218/* Rx FIFO 0/1 Status (RXF0S/RXF1S) */
 219#define RXFS_RFL        BIT(25)
 220#define RXFS_FF         BIT(24)
 221#define RXFS_FPI_OFF    16
 222#define RXFS_FPI_MASK   0x3f0000
 223#define RXFS_FGI_OFF    8
 224#define RXFS_FGI_MASK   0x3f00
 225#define RXFS_FFL_MASK   0x7f
 226
 227/* Rx Buffer / FIFO Element Size Configuration (RXESC) */
 228#define M_CAN_RXESC_8BYTES      0x0
 229#define M_CAN_RXESC_64BYTES     0x777
 230
 231/* Tx Buffer Configuration(TXBC) */
 232#define TXBC_NDTB_OFF           16
 233#define TXBC_NDTB_MASK          0x3f
 234
 235/* Tx Buffer Element Size Configuration(TXESC) */
 236#define TXESC_TBDS_8BYTES       0x0
 237#define TXESC_TBDS_64BYTES      0x7
 238
 239/* Tx Event FIFO Con.guration (TXEFC) */
 240#define TXEFC_EFS_OFF           16
 241#define TXEFC_EFS_MASK          0x3f
 242
 243/* Message RAM Configuration (in bytes) */
 244#define SIDF_ELEMENT_SIZE       4
 245#define XIDF_ELEMENT_SIZE       8
 246#define RXF0_ELEMENT_SIZE       72
 247#define RXF1_ELEMENT_SIZE       72
 248#define RXB_ELEMENT_SIZE        16
 249#define TXE_ELEMENT_SIZE        8
 250#define TXB_ELEMENT_SIZE        72
 251
 252/* Message RAM Elements */
 253#define M_CAN_FIFO_ID           0x0
 254#define M_CAN_FIFO_DLC          0x4
 255#define M_CAN_FIFO_DATA(n)      (0x8 + ((n) << 2))
 256
 257/* Rx Buffer Element */
 258/* R0 */
 259#define RX_BUF_ESI              BIT(31)
 260#define RX_BUF_XTD              BIT(30)
 261#define RX_BUF_RTR              BIT(29)
 262/* R1 */
 263#define RX_BUF_ANMF             BIT(31)
 264#define RX_BUF_EDL              BIT(21)
 265#define RX_BUF_BRS              BIT(20)
 266
 267/* Tx Buffer Element */
 268/* R0 */
 269#define TX_BUF_XTD              BIT(30)
 270#define TX_BUF_RTR              BIT(29)
 271
 272/* address offset and element number for each FIFO/Buffer in the Message RAM */
 273struct mram_cfg {
 274        u16 off;
 275        u8  num;
 276};
 277
 278/* m_can private data structure */
 279struct m_can_priv {
 280        struct can_priv can;    /* must be the first member */
 281        struct napi_struct napi;
 282        struct net_device *dev;
 283        struct device *device;
 284        struct clk *hclk;
 285        struct clk *cclk;
 286        void __iomem *base;
 287        u32 irqstatus;
 288
 289        /* message ram configuration */
 290        void __iomem *mram_base;
 291        struct mram_cfg mcfg[MRAM_CFG_NUM];
 292};
 293
 294static inline u32 m_can_read(const struct m_can_priv *priv, enum m_can_reg reg)
 295{
 296        return readl(priv->base + reg);
 297}
 298
 299static inline void m_can_write(const struct m_can_priv *priv,
 300                               enum m_can_reg reg, u32 val)
 301{
 302        writel(val, priv->base + reg);
 303}
 304
 305static inline u32 m_can_fifo_read(const struct m_can_priv *priv,
 306                                  u32 fgi, unsigned int offset)
 307{
 308        return readl(priv->mram_base + priv->mcfg[MRAM_RXF0].off +
 309                     fgi * RXF0_ELEMENT_SIZE + offset);
 310}
 311
 312static inline void m_can_fifo_write(const struct m_can_priv *priv,
 313                                    u32 fpi, unsigned int offset, u32 val)
 314{
 315        writel(val, priv->mram_base + priv->mcfg[MRAM_TXB].off +
 316               fpi * TXB_ELEMENT_SIZE + offset);
 317}
 318
 319static inline void m_can_config_endisable(const struct m_can_priv *priv,
 320                                          bool enable)
 321{
 322        u32 cccr = m_can_read(priv, M_CAN_CCCR);
 323        u32 timeout = 10;
 324        u32 val = 0;
 325
 326        if (enable) {
 327                /* enable m_can configuration */
 328                m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT);
 329                udelay(5);
 330                /* CCCR.CCE can only be set/reset while CCCR.INIT = '1' */
 331                m_can_write(priv, M_CAN_CCCR, cccr | CCCR_INIT | CCCR_CCE);
 332        } else {
 333                m_can_write(priv, M_CAN_CCCR, cccr & ~(CCCR_INIT | CCCR_CCE));
 334        }
 335
 336        /* there's a delay for module initialization */
 337        if (enable)
 338                val = CCCR_INIT | CCCR_CCE;
 339
 340        while ((m_can_read(priv, M_CAN_CCCR) & (CCCR_INIT | CCCR_CCE)) != val) {
 341                if (timeout == 0) {
 342                        netdev_warn(priv->dev, "Failed to init module\n");
 343                        return;
 344                }
 345                timeout--;
 346                udelay(1);
 347        }
 348}
 349
 350static inline void m_can_enable_all_interrupts(const struct m_can_priv *priv)
 351{
 352        m_can_write(priv, M_CAN_ILE, ILE_EINT0 | ILE_EINT1);
 353}
 354
 355static inline void m_can_disable_all_interrupts(const struct m_can_priv *priv)
 356{
 357        m_can_write(priv, M_CAN_ILE, 0x0);
 358}
 359
 360static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 361{
 362        struct net_device_stats *stats = &dev->stats;
 363        struct m_can_priv *priv = netdev_priv(dev);
 364        struct canfd_frame *cf;
 365        struct sk_buff *skb;
 366        u32 id, fgi, dlc;
 367        int i;
 368
 369        /* calculate the fifo get index for where to read data */
 370        fgi = (rxfs & RXFS_FGI_MASK) >> RXFS_FGI_OFF;
 371        dlc = m_can_fifo_read(priv, fgi, M_CAN_FIFO_DLC);
 372        if (dlc & RX_BUF_EDL)
 373                skb = alloc_canfd_skb(dev, &cf);
 374        else
 375                skb = alloc_can_skb(dev, (struct can_frame **)&cf);
 376        if (!skb) {
 377                stats->rx_dropped++;
 378                return;
 379        }
 380
 381        if (dlc & RX_BUF_EDL)
 382                cf->len = can_dlc2len((dlc >> 16) & 0x0F);
 383        else
 384                cf->len = get_can_dlc((dlc >> 16) & 0x0F);
 385
 386        id = m_can_fifo_read(priv, fgi, M_CAN_FIFO_ID);
 387        if (id & RX_BUF_XTD)
 388                cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
 389        else
 390                cf->can_id = (id >> 18) & CAN_SFF_MASK;
 391
 392        if (id & RX_BUF_ESI) {
 393                cf->flags |= CANFD_ESI;
 394                netdev_dbg(dev, "ESI Error\n");
 395        }
 396
 397        if (!(dlc & RX_BUF_EDL) && (id & RX_BUF_RTR)) {
 398                cf->can_id |= CAN_RTR_FLAG;
 399        } else {
 400                if (dlc & RX_BUF_BRS)
 401                        cf->flags |= CANFD_BRS;
 402
 403                for (i = 0; i < cf->len; i += 4)
 404                        *(u32 *)(cf->data + i) =
 405                                m_can_fifo_read(priv, fgi,
 406                                                M_CAN_FIFO_DATA(i / 4));
 407        }
 408
 409        /* acknowledge rx fifo 0 */
 410        m_can_write(priv, M_CAN_RXF0A, fgi);
 411
 412        stats->rx_packets++;
 413        stats->rx_bytes += cf->len;
 414
 415        netif_receive_skb(skb);
 416}
 417
 418static int m_can_do_rx_poll(struct net_device *dev, int quota)
 419{
 420        struct m_can_priv *priv = netdev_priv(dev);
 421        u32 pkts = 0;
 422        u32 rxfs;
 423
 424        rxfs = m_can_read(priv, M_CAN_RXF0S);
 425        if (!(rxfs & RXFS_FFL_MASK)) {
 426                netdev_dbg(dev, "no messages in fifo0\n");
 427                return 0;
 428        }
 429
 430        while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
 431                if (rxfs & RXFS_RFL)
 432                        netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
 433
 434                m_can_read_fifo(dev, rxfs);
 435
 436                quota--;
 437                pkts++;
 438                rxfs = m_can_read(priv, M_CAN_RXF0S);
 439        }
 440
 441        if (pkts)
 442                can_led_event(dev, CAN_LED_EVENT_RX);
 443
 444        return pkts;
 445}
 446
 447static int m_can_handle_lost_msg(struct net_device *dev)
 448{
 449        struct net_device_stats *stats = &dev->stats;
 450        struct sk_buff *skb;
 451        struct can_frame *frame;
 452
 453        netdev_err(dev, "msg lost in rxf0\n");
 454
 455        stats->rx_errors++;
 456        stats->rx_over_errors++;
 457
 458        skb = alloc_can_err_skb(dev, &frame);
 459        if (unlikely(!skb))
 460                return 0;
 461
 462        frame->can_id |= CAN_ERR_CRTL;
 463        frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 464
 465        netif_receive_skb(skb);
 466
 467        return 1;
 468}
 469
 470static int m_can_handle_lec_err(struct net_device *dev,
 471                                enum m_can_lec_type lec_type)
 472{
 473        struct m_can_priv *priv = netdev_priv(dev);
 474        struct net_device_stats *stats = &dev->stats;
 475        struct can_frame *cf;
 476        struct sk_buff *skb;
 477
 478        priv->can.can_stats.bus_error++;
 479        stats->rx_errors++;
 480
 481        /* propagate the error condition to the CAN stack */
 482        skb = alloc_can_err_skb(dev, &cf);
 483        if (unlikely(!skb))
 484                return 0;
 485
 486        /* check for 'last error code' which tells us the
 487         * type of the last error to occur on the CAN bus
 488         */
 489        cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 490        cf->data[2] |= CAN_ERR_PROT_UNSPEC;
 491
 492        switch (lec_type) {
 493        case LEC_STUFF_ERROR:
 494                netdev_dbg(dev, "stuff error\n");
 495                cf->data[2] |= CAN_ERR_PROT_STUFF;
 496                break;
 497        case LEC_FORM_ERROR:
 498                netdev_dbg(dev, "form error\n");
 499                cf->data[2] |= CAN_ERR_PROT_FORM;
 500                break;
 501        case LEC_ACK_ERROR:
 502                netdev_dbg(dev, "ack error\n");
 503                cf->data[3] |= (CAN_ERR_PROT_LOC_ACK |
 504                                CAN_ERR_PROT_LOC_ACK_DEL);
 505                break;
 506        case LEC_BIT1_ERROR:
 507                netdev_dbg(dev, "bit1 error\n");
 508                cf->data[2] |= CAN_ERR_PROT_BIT1;
 509                break;
 510        case LEC_BIT0_ERROR:
 511                netdev_dbg(dev, "bit0 error\n");
 512                cf->data[2] |= CAN_ERR_PROT_BIT0;
 513                break;
 514        case LEC_CRC_ERROR:
 515                netdev_dbg(dev, "CRC error\n");
 516                cf->data[3] |= (CAN_ERR_PROT_LOC_CRC_SEQ |
 517                                CAN_ERR_PROT_LOC_CRC_DEL);
 518                break;
 519        default:
 520                break;
 521        }
 522
 523        stats->rx_packets++;
 524        stats->rx_bytes += cf->can_dlc;
 525        netif_receive_skb(skb);
 526
 527        return 1;
 528}
 529
 530static int __m_can_get_berr_counter(const struct net_device *dev,
 531                                    struct can_berr_counter *bec)
 532{
 533        struct m_can_priv *priv = netdev_priv(dev);
 534        unsigned int ecr;
 535
 536        ecr = m_can_read(priv, M_CAN_ECR);
 537        bec->rxerr = (ecr & ECR_REC_MASK) >> ECR_REC_SHIFT;
 538        bec->txerr = ecr & ECR_TEC_MASK;
 539
 540        return 0;
 541}
 542
 543static int m_can_get_berr_counter(const struct net_device *dev,
 544                                  struct can_berr_counter *bec)
 545{
 546        struct m_can_priv *priv = netdev_priv(dev);
 547        int err;
 548
 549        err = clk_prepare_enable(priv->hclk);
 550        if (err)
 551                return err;
 552
 553        err = clk_prepare_enable(priv->cclk);
 554        if (err) {
 555                clk_disable_unprepare(priv->hclk);
 556                return err;
 557        }
 558
 559        __m_can_get_berr_counter(dev, bec);
 560
 561        clk_disable_unprepare(priv->cclk);
 562        clk_disable_unprepare(priv->hclk);
 563
 564        return 0;
 565}
 566
 567static int m_can_handle_state_change(struct net_device *dev,
 568                                     enum can_state new_state)
 569{
 570        struct m_can_priv *priv = netdev_priv(dev);
 571        struct net_device_stats *stats = &dev->stats;
 572        struct can_frame *cf;
 573        struct sk_buff *skb;
 574        struct can_berr_counter bec;
 575        unsigned int ecr;
 576
 577        switch (new_state) {
 578        case CAN_STATE_ERROR_ACTIVE:
 579                /* error warning state */
 580                priv->can.can_stats.error_warning++;
 581                priv->can.state = CAN_STATE_ERROR_WARNING;
 582                break;
 583        case CAN_STATE_ERROR_PASSIVE:
 584                /* error passive state */
 585                priv->can.can_stats.error_passive++;
 586                priv->can.state = CAN_STATE_ERROR_PASSIVE;
 587                break;
 588        case CAN_STATE_BUS_OFF:
 589                /* bus-off state */
 590                priv->can.state = CAN_STATE_BUS_OFF;
 591                m_can_disable_all_interrupts(priv);
 592                priv->can.can_stats.bus_off++;
 593                can_bus_off(dev);
 594                break;
 595        default:
 596                break;
 597        }
 598
 599        /* propagate the error condition to the CAN stack */
 600        skb = alloc_can_err_skb(dev, &cf);
 601        if (unlikely(!skb))
 602                return 0;
 603
 604        __m_can_get_berr_counter(dev, &bec);
 605
 606        switch (new_state) {
 607        case CAN_STATE_ERROR_ACTIVE:
 608                /* error warning state */
 609                cf->can_id |= CAN_ERR_CRTL;
 610                cf->data[1] = (bec.txerr > bec.rxerr) ?
 611                        CAN_ERR_CRTL_TX_WARNING :
 612                        CAN_ERR_CRTL_RX_WARNING;
 613                cf->data[6] = bec.txerr;
 614                cf->data[7] = bec.rxerr;
 615                break;
 616        case CAN_STATE_ERROR_PASSIVE:
 617                /* error passive state */
 618                cf->can_id |= CAN_ERR_CRTL;
 619                ecr = m_can_read(priv, M_CAN_ECR);
 620                if (ecr & ECR_RP)
 621                        cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 622                if (bec.txerr > 127)
 623                        cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
 624                cf->data[6] = bec.txerr;
 625                cf->data[7] = bec.rxerr;
 626                break;
 627        case CAN_STATE_BUS_OFF:
 628                /* bus-off state */
 629                cf->can_id |= CAN_ERR_BUSOFF;
 630                break;
 631        default:
 632                break;
 633        }
 634
 635        stats->rx_packets++;
 636        stats->rx_bytes += cf->can_dlc;
 637        netif_receive_skb(skb);
 638
 639        return 1;
 640}
 641
 642static int m_can_handle_state_errors(struct net_device *dev, u32 psr)
 643{
 644        struct m_can_priv *priv = netdev_priv(dev);
 645        int work_done = 0;
 646
 647        if ((psr & PSR_EW) &&
 648            (priv->can.state != CAN_STATE_ERROR_WARNING)) {
 649                netdev_dbg(dev, "entered error warning state\n");
 650                work_done += m_can_handle_state_change(dev,
 651                                                       CAN_STATE_ERROR_WARNING);
 652        }
 653
 654        if ((psr & PSR_EP) &&
 655            (priv->can.state != CAN_STATE_ERROR_PASSIVE)) {
 656                netdev_dbg(dev, "entered error passive state\n");
 657                work_done += m_can_handle_state_change(dev,
 658                                                       CAN_STATE_ERROR_PASSIVE);
 659        }
 660
 661        if ((psr & PSR_BO) &&
 662            (priv->can.state != CAN_STATE_BUS_OFF)) {
 663                netdev_dbg(dev, "entered error bus off state\n");
 664                work_done += m_can_handle_state_change(dev,
 665                                                       CAN_STATE_BUS_OFF);
 666        }
 667
 668        return work_done;
 669}
 670
 671static void m_can_handle_other_err(struct net_device *dev, u32 irqstatus)
 672{
 673        if (irqstatus & IR_WDI)
 674                netdev_err(dev, "Message RAM Watchdog event due to missing READY\n");
 675        if (irqstatus & IR_ELO)
 676                netdev_err(dev, "Error Logging Overflow\n");
 677        if (irqstatus & IR_BEU)
 678                netdev_err(dev, "Bit Error Uncorrected\n");
 679        if (irqstatus & IR_BEC)
 680                netdev_err(dev, "Bit Error Corrected\n");
 681        if (irqstatus & IR_TOO)
 682                netdev_err(dev, "Timeout reached\n");
 683        if (irqstatus & IR_MRAF)
 684                netdev_err(dev, "Message RAM access failure occurred\n");
 685}
 686
 687static inline bool is_lec_err(u32 psr)
 688{
 689        psr &= LEC_UNUSED;
 690
 691        return psr && (psr != LEC_UNUSED);
 692}
 693
 694static int m_can_handle_bus_errors(struct net_device *dev, u32 irqstatus,
 695                                   u32 psr)
 696{
 697        struct m_can_priv *priv = netdev_priv(dev);
 698        int work_done = 0;
 699
 700        if (irqstatus & IR_RF0L)
 701                work_done += m_can_handle_lost_msg(dev);
 702
 703        /* handle lec errors on the bus */
 704        if ((priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
 705            is_lec_err(psr))
 706                work_done += m_can_handle_lec_err(dev, psr & LEC_UNUSED);
 707
 708        /* other unproccessed error interrupts */
 709        m_can_handle_other_err(dev, irqstatus);
 710
 711        return work_done;
 712}
 713
 714static int m_can_poll(struct napi_struct *napi, int quota)
 715{
 716        struct net_device *dev = napi->dev;
 717        struct m_can_priv *priv = netdev_priv(dev);
 718        int work_done = 0;
 719        u32 irqstatus, psr;
 720
 721        irqstatus = priv->irqstatus | m_can_read(priv, M_CAN_IR);
 722        if (!irqstatus)
 723                goto end;
 724
 725        psr = m_can_read(priv, M_CAN_PSR);
 726        if (irqstatus & IR_ERR_STATE)
 727                work_done += m_can_handle_state_errors(dev, psr);
 728
 729        if (irqstatus & IR_ERR_BUS)
 730                work_done += m_can_handle_bus_errors(dev, irqstatus, psr);
 731
 732        if (irqstatus & IR_RF0N)
 733                work_done += m_can_do_rx_poll(dev, (quota - work_done));
 734
 735        if (work_done < quota) {
 736                napi_complete(napi);
 737                m_can_enable_all_interrupts(priv);
 738        }
 739
 740end:
 741        return work_done;
 742}
 743
 744static irqreturn_t m_can_isr(int irq, void *dev_id)
 745{
 746        struct net_device *dev = (struct net_device *)dev_id;
 747        struct m_can_priv *priv = netdev_priv(dev);
 748        struct net_device_stats *stats = &dev->stats;
 749        u32 ir;
 750
 751        ir = m_can_read(priv, M_CAN_IR);
 752        if (!ir)
 753                return IRQ_NONE;
 754
 755        /* ACK all irqs */
 756        if (ir & IR_ALL_INT)
 757                m_can_write(priv, M_CAN_IR, ir);
 758
 759        /* schedule NAPI in case of
 760         * - rx IRQ
 761         * - state change IRQ
 762         * - bus error IRQ and bus error reporting
 763         */
 764        if ((ir & IR_RF0N) || (ir & IR_ERR_ALL)) {
 765                priv->irqstatus = ir;
 766                m_can_disable_all_interrupts(priv);
 767                napi_schedule(&priv->napi);
 768        }
 769
 770        /* transmission complete interrupt */
 771        if (ir & IR_TC) {
 772                stats->tx_bytes += can_get_echo_skb(dev, 0);
 773                stats->tx_packets++;
 774                can_led_event(dev, CAN_LED_EVENT_TX);
 775                netif_wake_queue(dev);
 776        }
 777
 778        return IRQ_HANDLED;
 779}
 780
 781static const struct can_bittiming_const m_can_bittiming_const = {
 782        .name = KBUILD_MODNAME,
 783        .tseg1_min = 2,         /* Time segment 1 = prop_seg + phase_seg1 */
 784        .tseg1_max = 64,
 785        .tseg2_min = 1,         /* Time segment 2 = phase_seg2 */
 786        .tseg2_max = 16,
 787        .sjw_max = 16,
 788        .brp_min = 1,
 789        .brp_max = 1024,
 790        .brp_inc = 1,
 791};
 792
 793static const struct can_bittiming_const m_can_data_bittiming_const = {
 794        .name = KBUILD_MODNAME,
 795        .tseg1_min = 2,         /* Time segment 1 = prop_seg + phase_seg1 */
 796        .tseg1_max = 16,
 797        .tseg2_min = 1,         /* Time segment 2 = phase_seg2 */
 798        .tseg2_max = 8,
 799        .sjw_max = 4,
 800        .brp_min = 1,
 801        .brp_max = 32,
 802        .brp_inc = 1,
 803};
 804
 805static int m_can_set_bittiming(struct net_device *dev)
 806{
 807        struct m_can_priv *priv = netdev_priv(dev);
 808        const struct can_bittiming *bt = &priv->can.bittiming;
 809        const struct can_bittiming *dbt = &priv->can.data_bittiming;
 810        u16 brp, sjw, tseg1, tseg2;
 811        u32 reg_btp;
 812
 813        brp = bt->brp - 1;
 814        sjw = bt->sjw - 1;
 815        tseg1 = bt->prop_seg + bt->phase_seg1 - 1;
 816        tseg2 = bt->phase_seg2 - 1;
 817        reg_btp = (brp << BTR_BRP_SHIFT) | (sjw << BTR_SJW_SHIFT) |
 818                        (tseg1 << BTR_TSEG1_SHIFT) | (tseg2 << BTR_TSEG2_SHIFT);
 819        m_can_write(priv, M_CAN_BTP, reg_btp);
 820
 821        if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
 822                brp = dbt->brp - 1;
 823                sjw = dbt->sjw - 1;
 824                tseg1 = dbt->prop_seg + dbt->phase_seg1 - 1;
 825                tseg2 = dbt->phase_seg2 - 1;
 826                reg_btp = (brp << FBTR_FBRP_SHIFT) | (sjw << FBTR_FSJW_SHIFT) |
 827                                (tseg1 << FBTR_FTSEG1_SHIFT) |
 828                                (tseg2 << FBTR_FTSEG2_SHIFT);
 829                m_can_write(priv, M_CAN_FBTP, reg_btp);
 830        }
 831
 832        return 0;
 833}
 834
 835/* Configure M_CAN chip:
 836 * - set rx buffer/fifo element size
 837 * - configure rx fifo
 838 * - accept non-matching frame into fifo 0
 839 * - configure tx buffer
 840 * - configure mode
 841 * - setup bittiming
 842 */
 843static void m_can_chip_config(struct net_device *dev)
 844{
 845        struct m_can_priv *priv = netdev_priv(dev);
 846        u32 cccr, test;
 847
 848        m_can_config_endisable(priv, true);
 849
 850        /* RX Buffer/FIFO Element Size 64 bytes data field */
 851        m_can_write(priv, M_CAN_RXESC, M_CAN_RXESC_64BYTES);
 852
 853        /* Accept Non-matching Frames Into FIFO 0 */
 854        m_can_write(priv, M_CAN_GFC, 0x0);
 855
 856        /* only support one Tx Buffer currently */
 857        m_can_write(priv, M_CAN_TXBC, (1 << TXBC_NDTB_OFF) |
 858                    priv->mcfg[MRAM_TXB].off);
 859
 860        /* support 64 bytes payload */
 861        m_can_write(priv, M_CAN_TXESC, TXESC_TBDS_64BYTES);
 862
 863        m_can_write(priv, M_CAN_TXEFC, (1 << TXEFC_EFS_OFF) |
 864                    priv->mcfg[MRAM_TXE].off);
 865
 866        /* rx fifo configuration, blocking mode, fifo size 1 */
 867        m_can_write(priv, M_CAN_RXF0C,
 868                    (priv->mcfg[MRAM_RXF0].num << RXFC_FS_OFF) |
 869                    RXFC_FWM_1 | priv->mcfg[MRAM_RXF0].off);
 870
 871        m_can_write(priv, M_CAN_RXF1C,
 872                    (priv->mcfg[MRAM_RXF1].num << RXFC_FS_OFF) |
 873                    RXFC_FWM_1 | priv->mcfg[MRAM_RXF1].off);
 874
 875        cccr = m_can_read(priv, M_CAN_CCCR);
 876        cccr &= ~(CCCR_TEST | CCCR_MON | (CCCR_CMR_MASK << CCCR_CMR_SHIFT) |
 877                (CCCR_CME_MASK << CCCR_CME_SHIFT));
 878        test = m_can_read(priv, M_CAN_TEST);
 879        test &= ~TEST_LBCK;
 880
 881        if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 882                cccr |= CCCR_MON;
 883
 884        if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 885                cccr |= CCCR_TEST;
 886                test |= TEST_LBCK;
 887        }
 888
 889        if (priv->can.ctrlmode & CAN_CTRLMODE_FD)
 890                cccr |= CCCR_CME_CANFD_BRS << CCCR_CME_SHIFT;
 891
 892        m_can_write(priv, M_CAN_CCCR, cccr);
 893        m_can_write(priv, M_CAN_TEST, test);
 894
 895        /* enable interrupts */
 896        m_can_write(priv, M_CAN_IR, IR_ALL_INT);
 897        if (!(priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
 898                m_can_write(priv, M_CAN_IE, IR_ALL_INT & ~IR_ERR_LEC);
 899        else
 900                m_can_write(priv, M_CAN_IE, IR_ALL_INT);
 901
 902        /* route all interrupts to INT0 */
 903        m_can_write(priv, M_CAN_ILS, ILS_ALL_INT0);
 904
 905        /* set bittiming params */
 906        m_can_set_bittiming(dev);
 907
 908        m_can_config_endisable(priv, false);
 909}
 910
 911static void m_can_start(struct net_device *dev)
 912{
 913        struct m_can_priv *priv = netdev_priv(dev);
 914
 915        /* basic m_can configuration */
 916        m_can_chip_config(dev);
 917
 918        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 919
 920        m_can_enable_all_interrupts(priv);
 921}
 922
 923static int m_can_set_mode(struct net_device *dev, enum can_mode mode)
 924{
 925        switch (mode) {
 926        case CAN_MODE_START:
 927                m_can_start(dev);
 928                netif_wake_queue(dev);
 929                break;
 930        default:
 931                return -EOPNOTSUPP;
 932        }
 933
 934        return 0;
 935}
 936
 937static void free_m_can_dev(struct net_device *dev)
 938{
 939        free_candev(dev);
 940}
 941
 942static struct net_device *alloc_m_can_dev(void)
 943{
 944        struct net_device *dev;
 945        struct m_can_priv *priv;
 946
 947        dev = alloc_candev(sizeof(*priv), 1);
 948        if (!dev)
 949                return NULL;
 950
 951        priv = netdev_priv(dev);
 952        netif_napi_add(dev, &priv->napi, m_can_poll, M_CAN_NAPI_WEIGHT);
 953
 954        priv->dev = dev;
 955        priv->can.bittiming_const = &m_can_bittiming_const;
 956        priv->can.data_bittiming_const = &m_can_data_bittiming_const;
 957        priv->can.do_set_mode = m_can_set_mode;
 958        priv->can.do_get_berr_counter = m_can_get_berr_counter;
 959
 960        /* CAN_CTRLMODE_FD_NON_ISO is fixed with M_CAN IP v3.0.1 */
 961        priv->can.ctrlmode = CAN_CTRLMODE_FD_NON_ISO;
 962
 963        /* CAN_CTRLMODE_FD_NON_ISO can not be changed with M_CAN IP v3.0.1 */
 964        priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 965                                        CAN_CTRLMODE_LISTENONLY |
 966                                        CAN_CTRLMODE_BERR_REPORTING |
 967                                        CAN_CTRLMODE_FD;
 968
 969        return dev;
 970}
 971
 972static int m_can_open(struct net_device *dev)
 973{
 974        struct m_can_priv *priv = netdev_priv(dev);
 975        int err;
 976
 977        err = clk_prepare_enable(priv->hclk);
 978        if (err)
 979                return err;
 980
 981        err = clk_prepare_enable(priv->cclk);
 982        if (err)
 983                goto exit_disable_hclk;
 984
 985        /* open the can device */
 986        err = open_candev(dev);
 987        if (err) {
 988                netdev_err(dev, "failed to open can device\n");
 989                goto exit_disable_cclk;
 990        }
 991
 992        /* register interrupt handler */
 993        err = request_irq(dev->irq, m_can_isr, IRQF_SHARED, dev->name,
 994                          dev);
 995        if (err < 0) {
 996                netdev_err(dev, "failed to request interrupt\n");
 997                goto exit_irq_fail;
 998        }
 999
1000        /* start the m_can controller */
1001        m_can_start(dev);
1002
1003        can_led_event(dev, CAN_LED_EVENT_OPEN);
1004        napi_enable(&priv->napi);
1005        netif_start_queue(dev);
1006
1007        return 0;
1008
1009exit_irq_fail:
1010        close_candev(dev);
1011exit_disable_cclk:
1012        clk_disable_unprepare(priv->cclk);
1013exit_disable_hclk:
1014        clk_disable_unprepare(priv->hclk);
1015        return err;
1016}
1017
1018static void m_can_stop(struct net_device *dev)
1019{
1020        struct m_can_priv *priv = netdev_priv(dev);
1021
1022        /* disable all interrupts */
1023        m_can_disable_all_interrupts(priv);
1024
1025        clk_disable_unprepare(priv->hclk);
1026        clk_disable_unprepare(priv->cclk);
1027
1028        /* set the state as STOPPED */
1029        priv->can.state = CAN_STATE_STOPPED;
1030}
1031
1032static int m_can_close(struct net_device *dev)
1033{
1034        struct m_can_priv *priv = netdev_priv(dev);
1035
1036        netif_stop_queue(dev);
1037        napi_disable(&priv->napi);
1038        m_can_stop(dev);
1039        free_irq(dev->irq, dev);
1040        close_candev(dev);
1041        can_led_event(dev, CAN_LED_EVENT_STOP);
1042
1043        return 0;
1044}
1045
1046static netdev_tx_t m_can_start_xmit(struct sk_buff *skb,
1047                                    struct net_device *dev)
1048{
1049        struct m_can_priv *priv = netdev_priv(dev);
1050        struct canfd_frame *cf = (struct canfd_frame *)skb->data;
1051        u32 id, cccr;
1052        int i;
1053
1054        if (can_dropped_invalid_skb(dev, skb))
1055                return NETDEV_TX_OK;
1056
1057        netif_stop_queue(dev);
1058
1059        if (cf->can_id & CAN_EFF_FLAG) {
1060                id = cf->can_id & CAN_EFF_MASK;
1061                id |= TX_BUF_XTD;
1062        } else {
1063                id = ((cf->can_id & CAN_SFF_MASK) << 18);
1064        }
1065
1066        if (cf->can_id & CAN_RTR_FLAG)
1067                id |= TX_BUF_RTR;
1068
1069        /* message ram configuration */
1070        m_can_fifo_write(priv, 0, M_CAN_FIFO_ID, id);
1071        m_can_fifo_write(priv, 0, M_CAN_FIFO_DLC, can_len2dlc(cf->len) << 16);
1072
1073        for (i = 0; i < cf->len; i += 4)
1074                m_can_fifo_write(priv, 0, M_CAN_FIFO_DATA(i / 4),
1075                                 *(u32 *)(cf->data + i));
1076
1077        can_put_echo_skb(skb, dev, 0);
1078
1079        if (priv->can.ctrlmode & CAN_CTRLMODE_FD) {
1080                cccr = m_can_read(priv, M_CAN_CCCR);
1081                cccr &= ~(CCCR_CMR_MASK << CCCR_CMR_SHIFT);
1082                if (can_is_canfd_skb(skb)) {
1083                        if (cf->flags & CANFD_BRS)
1084                                cccr |= CCCR_CMR_CANFD_BRS << CCCR_CMR_SHIFT;
1085                        else
1086                                cccr |= CCCR_CMR_CANFD << CCCR_CMR_SHIFT;
1087                } else {
1088                        cccr |= CCCR_CMR_CAN << CCCR_CMR_SHIFT;
1089                }
1090                m_can_write(priv, M_CAN_CCCR, cccr);
1091        }
1092
1093        /* enable first TX buffer to start transfer  */
1094        m_can_write(priv, M_CAN_TXBTIE, 0x1);
1095        m_can_write(priv, M_CAN_TXBAR, 0x1);
1096
1097        return NETDEV_TX_OK;
1098}
1099
1100static const struct net_device_ops m_can_netdev_ops = {
1101        .ndo_open = m_can_open,
1102        .ndo_stop = m_can_close,
1103        .ndo_start_xmit = m_can_start_xmit,
1104        .ndo_change_mtu = can_change_mtu,
1105};
1106
1107static int register_m_can_dev(struct net_device *dev)
1108{
1109        dev->flags |= IFF_ECHO; /* we support local echo */
1110        dev->netdev_ops = &m_can_netdev_ops;
1111
1112        return register_candev(dev);
1113}
1114
1115static int m_can_of_parse_mram(struct platform_device *pdev,
1116                               struct m_can_priv *priv)
1117{
1118        struct device_node *np = pdev->dev.of_node;
1119        struct resource *res;
1120        void __iomem *addr;
1121        u32 out_val[MRAM_CFG_LEN];
1122        int i, start, end, ret;
1123
1124        /* message ram could be shared */
1125        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "message_ram");
1126        if (!res)
1127                return -ENODEV;
1128
1129        addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
1130        if (!addr)
1131                return -ENOMEM;
1132
1133        /* get message ram configuration */
1134        ret = of_property_read_u32_array(np, "bosch,mram-cfg",
1135                                         out_val, sizeof(out_val) / 4);
1136        if (ret) {
1137                dev_err(&pdev->dev, "can not get message ram configuration\n");
1138                return -ENODEV;
1139        }
1140
1141        priv->mram_base = addr;
1142        priv->mcfg[MRAM_SIDF].off = out_val[0];
1143        priv->mcfg[MRAM_SIDF].num = out_val[1];
1144        priv->mcfg[MRAM_XIDF].off = priv->mcfg[MRAM_SIDF].off +
1145                        priv->mcfg[MRAM_SIDF].num * SIDF_ELEMENT_SIZE;
1146        priv->mcfg[MRAM_XIDF].num = out_val[2];
1147        priv->mcfg[MRAM_RXF0].off = priv->mcfg[MRAM_XIDF].off +
1148                        priv->mcfg[MRAM_XIDF].num * XIDF_ELEMENT_SIZE;
1149        priv->mcfg[MRAM_RXF0].num = out_val[3] & RXFC_FS_MASK;
1150        priv->mcfg[MRAM_RXF1].off = priv->mcfg[MRAM_RXF0].off +
1151                        priv->mcfg[MRAM_RXF0].num * RXF0_ELEMENT_SIZE;
1152        priv->mcfg[MRAM_RXF1].num = out_val[4] & RXFC_FS_MASK;
1153        priv->mcfg[MRAM_RXB].off = priv->mcfg[MRAM_RXF1].off +
1154                        priv->mcfg[MRAM_RXF1].num * RXF1_ELEMENT_SIZE;
1155        priv->mcfg[MRAM_RXB].num = out_val[5];
1156        priv->mcfg[MRAM_TXE].off = priv->mcfg[MRAM_RXB].off +
1157                        priv->mcfg[MRAM_RXB].num * RXB_ELEMENT_SIZE;
1158        priv->mcfg[MRAM_TXE].num = out_val[6];
1159        priv->mcfg[MRAM_TXB].off = priv->mcfg[MRAM_TXE].off +
1160                        priv->mcfg[MRAM_TXE].num * TXE_ELEMENT_SIZE;
1161        priv->mcfg[MRAM_TXB].num = out_val[7] & TXBC_NDTB_MASK;
1162
1163        dev_dbg(&pdev->dev, "mram_base %p sidf 0x%x %d xidf 0x%x %d rxf0 0x%x %d rxf1 0x%x %d rxb 0x%x %d txe 0x%x %d txb 0x%x %d\n",
1164                priv->mram_base,
1165                priv->mcfg[MRAM_SIDF].off, priv->mcfg[MRAM_SIDF].num,
1166                priv->mcfg[MRAM_XIDF].off, priv->mcfg[MRAM_XIDF].num,
1167                priv->mcfg[MRAM_RXF0].off, priv->mcfg[MRAM_RXF0].num,
1168                priv->mcfg[MRAM_RXF1].off, priv->mcfg[MRAM_RXF1].num,
1169                priv->mcfg[MRAM_RXB].off, priv->mcfg[MRAM_RXB].num,
1170                priv->mcfg[MRAM_TXE].off, priv->mcfg[MRAM_TXE].num,
1171                priv->mcfg[MRAM_TXB].off, priv->mcfg[MRAM_TXB].num);
1172
1173        /* initialize the entire Message RAM in use to avoid possible
1174         * ECC/parity checksum errors when reading an uninitialized buffer
1175         */
1176        start = priv->mcfg[MRAM_SIDF].off;
1177        end = priv->mcfg[MRAM_TXB].off +
1178                priv->mcfg[MRAM_TXB].num * TXB_ELEMENT_SIZE;
1179        for (i = start; i < end; i += 4)
1180                writel(0x0, priv->mram_base + i);
1181
1182        return 0;
1183}
1184
1185static int m_can_plat_probe(struct platform_device *pdev)
1186{
1187        struct net_device *dev;
1188        struct m_can_priv *priv;
1189        struct resource *res;
1190        void __iomem *addr;
1191        struct clk *hclk, *cclk;
1192        int irq, ret;
1193
1194        hclk = devm_clk_get(&pdev->dev, "hclk");
1195        cclk = devm_clk_get(&pdev->dev, "cclk");
1196        if (IS_ERR(hclk) || IS_ERR(cclk)) {
1197                dev_err(&pdev->dev, "no clock find\n");
1198                return -ENODEV;
1199        }
1200
1201        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "m_can");
1202        addr = devm_ioremap_resource(&pdev->dev, res);
1203        irq = platform_get_irq_byname(pdev, "int0");
1204        if (IS_ERR(addr) || irq < 0)
1205                return -EINVAL;
1206
1207        /* allocate the m_can device */
1208        dev = alloc_m_can_dev();
1209        if (!dev)
1210                return -ENOMEM;
1211
1212        priv = netdev_priv(dev);
1213        dev->irq = irq;
1214        priv->base = addr;
1215        priv->device = &pdev->dev;
1216        priv->hclk = hclk;
1217        priv->cclk = cclk;
1218        priv->can.clock.freq = clk_get_rate(cclk);
1219
1220        ret = m_can_of_parse_mram(pdev, priv);
1221        if (ret)
1222                goto failed_free_dev;
1223
1224        platform_set_drvdata(pdev, dev);
1225        SET_NETDEV_DEV(dev, &pdev->dev);
1226
1227        ret = register_m_can_dev(dev);
1228        if (ret) {
1229                dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
1230                        KBUILD_MODNAME, ret);
1231                goto failed_free_dev;
1232        }
1233
1234        devm_can_led_init(dev);
1235
1236        dev_info(&pdev->dev, "%s device registered (regs=%p, irq=%d)\n",
1237                 KBUILD_MODNAME, priv->base, dev->irq);
1238
1239        return 0;
1240
1241failed_free_dev:
1242        free_m_can_dev(dev);
1243        return ret;
1244}
1245
1246static __maybe_unused int m_can_suspend(struct device *dev)
1247{
1248        struct net_device *ndev = dev_get_drvdata(dev);
1249        struct m_can_priv *priv = netdev_priv(ndev);
1250
1251        if (netif_running(ndev)) {
1252                netif_stop_queue(ndev);
1253                netif_device_detach(ndev);
1254        }
1255
1256        /* TODO: enter low power */
1257
1258        priv->can.state = CAN_STATE_SLEEPING;
1259
1260        return 0;
1261}
1262
1263static __maybe_unused int m_can_resume(struct device *dev)
1264{
1265        struct net_device *ndev = dev_get_drvdata(dev);
1266        struct m_can_priv *priv = netdev_priv(ndev);
1267
1268        /* TODO: exit low power */
1269
1270        priv->can.state = CAN_STATE_ERROR_ACTIVE;
1271
1272        if (netif_running(ndev)) {
1273                netif_device_attach(ndev);
1274                netif_start_queue(ndev);
1275        }
1276
1277        return 0;
1278}
1279
1280static void unregister_m_can_dev(struct net_device *dev)
1281{
1282        unregister_candev(dev);
1283}
1284
1285static int m_can_plat_remove(struct platform_device *pdev)
1286{
1287        struct net_device *dev = platform_get_drvdata(pdev);
1288
1289        unregister_m_can_dev(dev);
1290        platform_set_drvdata(pdev, NULL);
1291
1292        free_m_can_dev(dev);
1293
1294        return 0;
1295}
1296
1297static const struct dev_pm_ops m_can_pmops = {
1298        SET_SYSTEM_SLEEP_PM_OPS(m_can_suspend, m_can_resume)
1299};
1300
1301static const struct of_device_id m_can_of_table[] = {
1302        { .compatible = "bosch,m_can", .data = NULL },
1303        { /* sentinel */ },
1304};
1305MODULE_DEVICE_TABLE(of, m_can_of_table);
1306
1307static struct platform_driver m_can_plat_driver = {
1308        .driver = {
1309                .name = KBUILD_MODNAME,
1310                .of_match_table = m_can_of_table,
1311                .pm     = &m_can_pmops,
1312        },
1313        .probe = m_can_plat_probe,
1314        .remove = m_can_plat_remove,
1315};
1316
1317module_platform_driver(m_can_plat_driver);
1318
1319MODULE_AUTHOR("Dong Aisheng <b29396@freescale.com>");
1320MODULE_LICENSE("GPL v2");
1321MODULE_DESCRIPTION("CAN bus driver for Bosch M_CAN controller");
1322