linux/drivers/net/can/flexcan.c
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   1/*
   2 * flexcan.c - FLEXCAN CAN controller driver
   3 *
   4 * Copyright (c) 2005-2006 Varma Electronics Oy
   5 * Copyright (c) 2009 Sascha Hauer, Pengutronix
   6 * Copyright (c) 2010-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
   7 * Copyright (c) 2014 David Jander, Protonic Holland
   8 *
   9 * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
  10 *
  11 * LICENCE:
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License as
  14 * published by the Free Software Foundation version 2.
  15 *
  16 * This program is distributed in the hope that it will be useful,
  17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 * GNU General Public License for more details.
  20 *
  21 */
  22
  23#include <linux/netdevice.h>
  24#include <linux/can.h>
  25#include <linux/can/dev.h>
  26#include <linux/can/error.h>
  27#include <linux/can/led.h>
  28#include <linux/can/rx-offload.h>
  29#include <linux/clk.h>
  30#include <linux/delay.h>
  31#include <linux/interrupt.h>
  32#include <linux/io.h>
  33#include <linux/module.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
  39#define DRV_NAME                        "flexcan"
  40
  41/* 8 for RX fifo and 2 error handling */
  42#define FLEXCAN_NAPI_WEIGHT             (8 + 2)
  43
  44/* FLEXCAN module configuration register (CANMCR) bits */
  45#define FLEXCAN_MCR_MDIS                BIT(31)
  46#define FLEXCAN_MCR_FRZ                 BIT(30)
  47#define FLEXCAN_MCR_FEN                 BIT(29)
  48#define FLEXCAN_MCR_HALT                BIT(28)
  49#define FLEXCAN_MCR_NOT_RDY             BIT(27)
  50#define FLEXCAN_MCR_WAK_MSK             BIT(26)
  51#define FLEXCAN_MCR_SOFTRST             BIT(25)
  52#define FLEXCAN_MCR_FRZ_ACK             BIT(24)
  53#define FLEXCAN_MCR_SUPV                BIT(23)
  54#define FLEXCAN_MCR_SLF_WAK             BIT(22)
  55#define FLEXCAN_MCR_WRN_EN              BIT(21)
  56#define FLEXCAN_MCR_LPM_ACK             BIT(20)
  57#define FLEXCAN_MCR_WAK_SRC             BIT(19)
  58#define FLEXCAN_MCR_DOZE                BIT(18)
  59#define FLEXCAN_MCR_SRX_DIS             BIT(17)
  60#define FLEXCAN_MCR_IRMQ                BIT(16)
  61#define FLEXCAN_MCR_LPRIO_EN            BIT(13)
  62#define FLEXCAN_MCR_AEN                 BIT(12)
  63/* MCR_MAXMB: maximum used MBs is MAXMB + 1 */
  64#define FLEXCAN_MCR_MAXMB(x)            ((x) & 0x7f)
  65#define FLEXCAN_MCR_IDAM_A              (0x0 << 8)
  66#define FLEXCAN_MCR_IDAM_B              (0x1 << 8)
  67#define FLEXCAN_MCR_IDAM_C              (0x2 << 8)
  68#define FLEXCAN_MCR_IDAM_D              (0x3 << 8)
  69
  70/* FLEXCAN control register (CANCTRL) bits */
  71#define FLEXCAN_CTRL_PRESDIV(x)         (((x) & 0xff) << 24)
  72#define FLEXCAN_CTRL_RJW(x)             (((x) & 0x03) << 22)
  73#define FLEXCAN_CTRL_PSEG1(x)           (((x) & 0x07) << 19)
  74#define FLEXCAN_CTRL_PSEG2(x)           (((x) & 0x07) << 16)
  75#define FLEXCAN_CTRL_BOFF_MSK           BIT(15)
  76#define FLEXCAN_CTRL_ERR_MSK            BIT(14)
  77#define FLEXCAN_CTRL_CLK_SRC            BIT(13)
  78#define FLEXCAN_CTRL_LPB                BIT(12)
  79#define FLEXCAN_CTRL_TWRN_MSK           BIT(11)
  80#define FLEXCAN_CTRL_RWRN_MSK           BIT(10)
  81#define FLEXCAN_CTRL_SMP                BIT(7)
  82#define FLEXCAN_CTRL_BOFF_REC           BIT(6)
  83#define FLEXCAN_CTRL_TSYN               BIT(5)
  84#define FLEXCAN_CTRL_LBUF               BIT(4)
  85#define FLEXCAN_CTRL_LOM                BIT(3)
  86#define FLEXCAN_CTRL_PROPSEG(x)         ((x) & 0x07)
  87#define FLEXCAN_CTRL_ERR_BUS            (FLEXCAN_CTRL_ERR_MSK)
  88#define FLEXCAN_CTRL_ERR_STATE \
  89        (FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
  90         FLEXCAN_CTRL_BOFF_MSK)
  91#define FLEXCAN_CTRL_ERR_ALL \
  92        (FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
  93
  94/* FLEXCAN control register 2 (CTRL2) bits */
  95#define FLEXCAN_CTRL2_ECRWRE            BIT(29)
  96#define FLEXCAN_CTRL2_WRMFRZ            BIT(28)
  97#define FLEXCAN_CTRL2_RFFN(x)           (((x) & 0x0f) << 24)
  98#define FLEXCAN_CTRL2_TASD(x)           (((x) & 0x1f) << 19)
  99#define FLEXCAN_CTRL2_MRP               BIT(18)
 100#define FLEXCAN_CTRL2_RRS               BIT(17)
 101#define FLEXCAN_CTRL2_EACEN             BIT(16)
 102
 103/* FLEXCAN memory error control register (MECR) bits */
 104#define FLEXCAN_MECR_ECRWRDIS           BIT(31)
 105#define FLEXCAN_MECR_HANCEI_MSK         BIT(19)
 106#define FLEXCAN_MECR_FANCEI_MSK         BIT(18)
 107#define FLEXCAN_MECR_CEI_MSK            BIT(16)
 108#define FLEXCAN_MECR_HAERRIE            BIT(15)
 109#define FLEXCAN_MECR_FAERRIE            BIT(14)
 110#define FLEXCAN_MECR_EXTERRIE           BIT(13)
 111#define FLEXCAN_MECR_RERRDIS            BIT(9)
 112#define FLEXCAN_MECR_ECCDIS             BIT(8)
 113#define FLEXCAN_MECR_NCEFAFRZ           BIT(7)
 114
 115/* FLEXCAN error and status register (ESR) bits */
 116#define FLEXCAN_ESR_TWRN_INT            BIT(17)
 117#define FLEXCAN_ESR_RWRN_INT            BIT(16)
 118#define FLEXCAN_ESR_BIT1_ERR            BIT(15)
 119#define FLEXCAN_ESR_BIT0_ERR            BIT(14)
 120#define FLEXCAN_ESR_ACK_ERR             BIT(13)
 121#define FLEXCAN_ESR_CRC_ERR             BIT(12)
 122#define FLEXCAN_ESR_FRM_ERR             BIT(11)
 123#define FLEXCAN_ESR_STF_ERR             BIT(10)
 124#define FLEXCAN_ESR_TX_WRN              BIT(9)
 125#define FLEXCAN_ESR_RX_WRN              BIT(8)
 126#define FLEXCAN_ESR_IDLE                BIT(7)
 127#define FLEXCAN_ESR_TXRX                BIT(6)
 128#define FLEXCAN_EST_FLT_CONF_SHIFT      (4)
 129#define FLEXCAN_ESR_FLT_CONF_MASK       (0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
 130#define FLEXCAN_ESR_FLT_CONF_ACTIVE     (0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
 131#define FLEXCAN_ESR_FLT_CONF_PASSIVE    (0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
 132#define FLEXCAN_ESR_BOFF_INT            BIT(2)
 133#define FLEXCAN_ESR_ERR_INT             BIT(1)
 134#define FLEXCAN_ESR_WAK_INT             BIT(0)
 135#define FLEXCAN_ESR_ERR_BUS \
 136        (FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
 137         FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
 138         FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
 139#define FLEXCAN_ESR_ERR_STATE \
 140        (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
 141#define FLEXCAN_ESR_ERR_ALL \
 142        (FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
 143#define FLEXCAN_ESR_ALL_INT \
 144        (FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
 145         FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
 146
 147/* FLEXCAN interrupt flag register (IFLAG) bits */
 148/* Errata ERR005829 step7: Reserve first valid MB */
 149#define FLEXCAN_TX_MB_RESERVED_OFF_FIFO 8
 150#define FLEXCAN_TX_MB_OFF_FIFO          9
 151#define FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP    0
 152#define FLEXCAN_TX_MB_OFF_TIMESTAMP             1
 153#define FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST       (FLEXCAN_TX_MB_OFF_TIMESTAMP + 1)
 154#define FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST        63
 155#define FLEXCAN_IFLAG_MB(x)             BIT(x)
 156#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW  BIT(7)
 157#define FLEXCAN_IFLAG_RX_FIFO_WARN      BIT(6)
 158#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE BIT(5)
 159
 160/* FLEXCAN message buffers */
 161#define FLEXCAN_MB_CODE_MASK            (0xf << 24)
 162#define FLEXCAN_MB_CODE_RX_BUSY_BIT     (0x1 << 24)
 163#define FLEXCAN_MB_CODE_RX_INACTIVE     (0x0 << 24)
 164#define FLEXCAN_MB_CODE_RX_EMPTY        (0x4 << 24)
 165#define FLEXCAN_MB_CODE_RX_FULL         (0x2 << 24)
 166#define FLEXCAN_MB_CODE_RX_OVERRUN      (0x6 << 24)
 167#define FLEXCAN_MB_CODE_RX_RANSWER      (0xa << 24)
 168
 169#define FLEXCAN_MB_CODE_TX_INACTIVE     (0x8 << 24)
 170#define FLEXCAN_MB_CODE_TX_ABORT        (0x9 << 24)
 171#define FLEXCAN_MB_CODE_TX_DATA         (0xc << 24)
 172#define FLEXCAN_MB_CODE_TX_TANSWER      (0xe << 24)
 173
 174#define FLEXCAN_MB_CNT_SRR              BIT(22)
 175#define FLEXCAN_MB_CNT_IDE              BIT(21)
 176#define FLEXCAN_MB_CNT_RTR              BIT(20)
 177#define FLEXCAN_MB_CNT_LENGTH(x)        (((x) & 0xf) << 16)
 178#define FLEXCAN_MB_CNT_TIMESTAMP(x)     ((x) & 0xffff)
 179
 180#define FLEXCAN_TIMEOUT_US              (50)
 181
 182/* FLEXCAN hardware feature flags
 183 *
 184 * Below is some version info we got:
 185 *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT Memory err RTR re-
 186 *                                Filter? connected?  detection  ception in MB
 187 *   MX25  FlexCAN2  03.00.00.00     no        no         no        no
 188 *   MX28  FlexCAN2  03.00.04.00    yes       yes         no        no
 189 *   MX35  FlexCAN2  03.00.00.00     no        no         no        no
 190 *   MX53  FlexCAN2  03.00.00.00    yes        no         no        no
 191 *   MX6s  FlexCAN3  10.00.12.00    yes       yes         no       yes
 192 *   VF610 FlexCAN3  ?               no       yes        yes       yes?
 193 *
 194 * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
 195 */
 196#define FLEXCAN_QUIRK_BROKEN_ERR_STATE  BIT(1) /* [TR]WRN_INT not connected */
 197#define FLEXCAN_QUIRK_DISABLE_RXFG      BIT(2) /* Disable RX FIFO Global mask */
 198#define FLEXCAN_QUIRK_ENABLE_EACEN_RRS  BIT(3) /* Enable EACEN and RRS bit in ctrl2 */
 199#define FLEXCAN_QUIRK_DISABLE_MECR      BIT(4) /* Disable Memory error detection */
 200#define FLEXCAN_QUIRK_USE_OFF_TIMESTAMP BIT(5) /* Use timestamp based offloading */
 201
 202/* Structure of the message buffer */
 203struct flexcan_mb {
 204        u32 can_ctrl;
 205        u32 can_id;
 206        u32 data[2];
 207};
 208
 209/* Structure of the hardware registers */
 210struct flexcan_regs {
 211        u32 mcr;                /* 0x00 */
 212        u32 ctrl;               /* 0x04 */
 213        u32 timer;              /* 0x08 */
 214        u32 _reserved1;         /* 0x0c */
 215        u32 rxgmask;            /* 0x10 */
 216        u32 rx14mask;           /* 0x14 */
 217        u32 rx15mask;           /* 0x18 */
 218        u32 ecr;                /* 0x1c */
 219        u32 esr;                /* 0x20 */
 220        u32 imask2;             /* 0x24 */
 221        u32 imask1;             /* 0x28 */
 222        u32 iflag2;             /* 0x2c */
 223        u32 iflag1;             /* 0x30 */
 224        union {                 /* 0x34 */
 225                u32 gfwr_mx28;  /* MX28, MX53 */
 226                u32 ctrl2;      /* MX6, VF610 */
 227        };
 228        u32 esr2;               /* 0x38 */
 229        u32 imeur;              /* 0x3c */
 230        u32 lrfr;               /* 0x40 */
 231        u32 crcr;               /* 0x44 */
 232        u32 rxfgmask;           /* 0x48 */
 233        u32 rxfir;              /* 0x4c */
 234        u32 _reserved3[12];     /* 0x50 */
 235        struct flexcan_mb mb[64];       /* 0x80 */
 236        /* FIFO-mode:
 237         *                      MB
 238         * 0x080...0x08f        0       RX message buffer
 239         * 0x090...0x0df        1-5     reserverd
 240         * 0x0e0...0x0ff        6-7     8 entry ID table
 241         *                              (mx25, mx28, mx35, mx53)
 242         * 0x0e0...0x2df        6-7..37 8..128 entry ID table
 243         *                              size conf'ed via ctrl2::RFFN
 244         *                              (mx6, vf610)
 245         */
 246        u32 _reserved4[256];    /* 0x480 */
 247        u32 rximr[64];          /* 0x880 */
 248        u32 _reserved5[24];     /* 0x980 */
 249        u32 gfwr_mx6;           /* 0x9e0 - MX6 */
 250        u32 _reserved6[63];     /* 0x9e4 */
 251        u32 mecr;               /* 0xae0 */
 252        u32 erriar;             /* 0xae4 */
 253        u32 erridpr;            /* 0xae8 */
 254        u32 errippr;            /* 0xaec */
 255        u32 rerrar;             /* 0xaf0 */
 256        u32 rerrdr;             /* 0xaf4 */
 257        u32 rerrsynr;           /* 0xaf8 */
 258        u32 errsr;              /* 0xafc */
 259};
 260
 261struct flexcan_devtype_data {
 262        u32 quirks;             /* quirks needed for different IP cores */
 263};
 264
 265struct flexcan_priv {
 266        struct can_priv can;
 267        struct can_rx_offload offload;
 268
 269        struct flexcan_regs __iomem *regs;
 270        struct flexcan_mb __iomem *tx_mb;
 271        struct flexcan_mb __iomem *tx_mb_reserved;
 272        u8 tx_mb_idx;
 273        u32 reg_ctrl_default;
 274        u32 reg_imask1_default;
 275        u32 reg_imask2_default;
 276
 277        struct clk *clk_ipg;
 278        struct clk *clk_per;
 279        const struct flexcan_devtype_data *devtype_data;
 280        struct regulator *reg_xceiver;
 281};
 282
 283static const struct flexcan_devtype_data fsl_p1010_devtype_data = {
 284        .quirks = FLEXCAN_QUIRK_BROKEN_ERR_STATE,
 285};
 286
 287static const struct flexcan_devtype_data fsl_imx28_devtype_data;
 288
 289static const struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 290        .quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 291                FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
 292};
 293
 294static const struct flexcan_devtype_data fsl_vf610_devtype_data = {
 295        .quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_ENABLE_EACEN_RRS |
 296                FLEXCAN_QUIRK_DISABLE_MECR | FLEXCAN_QUIRK_USE_OFF_TIMESTAMP,
 297};
 298
 299static const struct can_bittiming_const flexcan_bittiming_const = {
 300        .name = DRV_NAME,
 301        .tseg1_min = 4,
 302        .tseg1_max = 16,
 303        .tseg2_min = 2,
 304        .tseg2_max = 8,
 305        .sjw_max = 4,
 306        .brp_min = 1,
 307        .brp_max = 256,
 308        .brp_inc = 1,
 309};
 310
 311/* Abstract off the read/write for arm versus ppc. This
 312 * assumes that PPC uses big-endian registers and everything
 313 * else uses little-endian registers, independent of CPU
 314 * endianness.
 315 */
 316#if defined(CONFIG_PPC)
 317static inline u32 flexcan_read(void __iomem *addr)
 318{
 319        return in_be32(addr);
 320}
 321
 322static inline void flexcan_write(u32 val, void __iomem *addr)
 323{
 324        out_be32(addr, val);
 325}
 326#else
 327static inline u32 flexcan_read(void __iomem *addr)
 328{
 329        return readl(addr);
 330}
 331
 332static inline void flexcan_write(u32 val, void __iomem *addr)
 333{
 334        writel(val, addr);
 335}
 336#endif
 337
 338static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
 339{
 340        if (!priv->reg_xceiver)
 341                return 0;
 342
 343        return regulator_enable(priv->reg_xceiver);
 344}
 345
 346static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
 347{
 348        if (!priv->reg_xceiver)
 349                return 0;
 350
 351        return regulator_disable(priv->reg_xceiver);
 352}
 353
 354static int flexcan_chip_enable(struct flexcan_priv *priv)
 355{
 356        struct flexcan_regs __iomem *regs = priv->regs;
 357        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 358        u32 reg;
 359
 360        reg = flexcan_read(&regs->mcr);
 361        reg &= ~FLEXCAN_MCR_MDIS;
 362        flexcan_write(reg, &regs->mcr);
 363
 364        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 365                udelay(10);
 366
 367        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
 368                return -ETIMEDOUT;
 369
 370        return 0;
 371}
 372
 373static int flexcan_chip_disable(struct flexcan_priv *priv)
 374{
 375        struct flexcan_regs __iomem *regs = priv->regs;
 376        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 377        u32 reg;
 378
 379        reg = flexcan_read(&regs->mcr);
 380        reg |= FLEXCAN_MCR_MDIS;
 381        flexcan_write(reg, &regs->mcr);
 382
 383        while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 384                udelay(10);
 385
 386        if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 387                return -ETIMEDOUT;
 388
 389        return 0;
 390}
 391
 392static int flexcan_chip_freeze(struct flexcan_priv *priv)
 393{
 394        struct flexcan_regs __iomem *regs = priv->regs;
 395        unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
 396        u32 reg;
 397
 398        reg = flexcan_read(&regs->mcr);
 399        reg |= FLEXCAN_MCR_HALT;
 400        flexcan_write(reg, &regs->mcr);
 401
 402        while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 403                udelay(100);
 404
 405        if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 406                return -ETIMEDOUT;
 407
 408        return 0;
 409}
 410
 411static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
 412{
 413        struct flexcan_regs __iomem *regs = priv->regs;
 414        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 415        u32 reg;
 416
 417        reg = flexcan_read(&regs->mcr);
 418        reg &= ~FLEXCAN_MCR_HALT;
 419        flexcan_write(reg, &regs->mcr);
 420
 421        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 422                udelay(10);
 423
 424        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
 425                return -ETIMEDOUT;
 426
 427        return 0;
 428}
 429
 430static int flexcan_chip_softreset(struct flexcan_priv *priv)
 431{
 432        struct flexcan_regs __iomem *regs = priv->regs;
 433        unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 434
 435        flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
 436        while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
 437                udelay(10);
 438
 439        if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
 440                return -ETIMEDOUT;
 441
 442        return 0;
 443}
 444
 445static int __flexcan_get_berr_counter(const struct net_device *dev,
 446                                      struct can_berr_counter *bec)
 447{
 448        const struct flexcan_priv *priv = netdev_priv(dev);
 449        struct flexcan_regs __iomem *regs = priv->regs;
 450        u32 reg = flexcan_read(&regs->ecr);
 451
 452        bec->txerr = (reg >> 0) & 0xff;
 453        bec->rxerr = (reg >> 8) & 0xff;
 454
 455        return 0;
 456}
 457
 458static int flexcan_get_berr_counter(const struct net_device *dev,
 459                                    struct can_berr_counter *bec)
 460{
 461        const struct flexcan_priv *priv = netdev_priv(dev);
 462        int err;
 463
 464        err = clk_prepare_enable(priv->clk_ipg);
 465        if (err)
 466                return err;
 467
 468        err = clk_prepare_enable(priv->clk_per);
 469        if (err)
 470                goto out_disable_ipg;
 471
 472        err = __flexcan_get_berr_counter(dev, bec);
 473
 474        clk_disable_unprepare(priv->clk_per);
 475 out_disable_ipg:
 476        clk_disable_unprepare(priv->clk_ipg);
 477
 478        return err;
 479}
 480
 481static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 482{
 483        const struct flexcan_priv *priv = netdev_priv(dev);
 484        struct can_frame *cf = (struct can_frame *)skb->data;
 485        u32 can_id;
 486        u32 data;
 487        u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (cf->can_dlc << 16);
 488
 489        if (can_dropped_invalid_skb(dev, skb))
 490                return NETDEV_TX_OK;
 491
 492        netif_stop_queue(dev);
 493
 494        if (cf->can_id & CAN_EFF_FLAG) {
 495                can_id = cf->can_id & CAN_EFF_MASK;
 496                ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
 497        } else {
 498                can_id = (cf->can_id & CAN_SFF_MASK) << 18;
 499        }
 500
 501        if (cf->can_id & CAN_RTR_FLAG)
 502                ctrl |= FLEXCAN_MB_CNT_RTR;
 503
 504        if (cf->can_dlc > 0) {
 505                data = be32_to_cpup((__be32 *)&cf->data[0]);
 506                flexcan_write(data, &priv->tx_mb->data[0]);
 507        }
 508        if (cf->can_dlc > 3) {
 509                data = be32_to_cpup((__be32 *)&cf->data[4]);
 510                flexcan_write(data, &priv->tx_mb->data[1]);
 511        }
 512
 513        can_put_echo_skb(skb, dev, 0);
 514
 515        flexcan_write(can_id, &priv->tx_mb->can_id);
 516        flexcan_write(ctrl, &priv->tx_mb->can_ctrl);
 517
 518        /* Errata ERR005829 step8:
 519         * Write twice INACTIVE(0x8) code to first MB.
 520         */
 521        flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 522                      &priv->tx_mb_reserved->can_ctrl);
 523        flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 524                      &priv->tx_mb_reserved->can_ctrl);
 525
 526        return NETDEV_TX_OK;
 527}
 528
 529static void flexcan_irq_bus_err(struct net_device *dev, u32 reg_esr)
 530{
 531        struct flexcan_priv *priv = netdev_priv(dev);
 532        struct sk_buff *skb;
 533        struct can_frame *cf;
 534        bool rx_errors = false, tx_errors = false;
 535
 536        skb = alloc_can_err_skb(dev, &cf);
 537        if (unlikely(!skb))
 538                return;
 539
 540        cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 541
 542        if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
 543                netdev_dbg(dev, "BIT1_ERR irq\n");
 544                cf->data[2] |= CAN_ERR_PROT_BIT1;
 545                tx_errors = true;
 546        }
 547        if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
 548                netdev_dbg(dev, "BIT0_ERR irq\n");
 549                cf->data[2] |= CAN_ERR_PROT_BIT0;
 550                tx_errors = true;
 551        }
 552        if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
 553                netdev_dbg(dev, "ACK_ERR irq\n");
 554                cf->can_id |= CAN_ERR_ACK;
 555                cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 556                tx_errors = true;
 557        }
 558        if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
 559                netdev_dbg(dev, "CRC_ERR irq\n");
 560                cf->data[2] |= CAN_ERR_PROT_BIT;
 561                cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 562                rx_errors = true;
 563        }
 564        if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
 565                netdev_dbg(dev, "FRM_ERR irq\n");
 566                cf->data[2] |= CAN_ERR_PROT_FORM;
 567                rx_errors = true;
 568        }
 569        if (reg_esr & FLEXCAN_ESR_STF_ERR) {
 570                netdev_dbg(dev, "STF_ERR irq\n");
 571                cf->data[2] |= CAN_ERR_PROT_STUFF;
 572                rx_errors = true;
 573        }
 574
 575        priv->can.can_stats.bus_error++;
 576        if (rx_errors)
 577                dev->stats.rx_errors++;
 578        if (tx_errors)
 579                dev->stats.tx_errors++;
 580
 581        can_rx_offload_irq_queue_err_skb(&priv->offload, skb);
 582}
 583
 584static void flexcan_irq_state(struct net_device *dev, u32 reg_esr)
 585{
 586        struct flexcan_priv *priv = netdev_priv(dev);
 587        struct sk_buff *skb;
 588        struct can_frame *cf;
 589        enum can_state new_state, rx_state, tx_state;
 590        int flt;
 591        struct can_berr_counter bec;
 592
 593        flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
 594        if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
 595                tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
 596                        CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
 597                rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
 598                        CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
 599                new_state = max(tx_state, rx_state);
 600        } else {
 601                __flexcan_get_berr_counter(dev, &bec);
 602                new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
 603                        CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
 604                rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
 605                tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
 606        }
 607
 608        /* state hasn't changed */
 609        if (likely(new_state == priv->can.state))
 610                return;
 611
 612        skb = alloc_can_err_skb(dev, &cf);
 613        if (unlikely(!skb))
 614                return;
 615
 616        can_change_state(dev, cf, tx_state, rx_state);
 617
 618        if (unlikely(new_state == CAN_STATE_BUS_OFF))
 619                can_bus_off(dev);
 620
 621        can_rx_offload_irq_queue_err_skb(&priv->offload, skb);
 622}
 623
 624static inline struct flexcan_priv *rx_offload_to_priv(struct can_rx_offload *offload)
 625{
 626        return container_of(offload, struct flexcan_priv, offload);
 627}
 628
 629static unsigned int flexcan_mailbox_read(struct can_rx_offload *offload,
 630                                         struct can_frame *cf,
 631                                         u32 *timestamp, unsigned int n)
 632{
 633        struct flexcan_priv *priv = rx_offload_to_priv(offload);
 634        struct flexcan_regs __iomem *regs = priv->regs;
 635        struct flexcan_mb __iomem *mb = &regs->mb[n];
 636        u32 reg_ctrl, reg_id, reg_iflag1;
 637
 638        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 639                u32 code;
 640
 641                do {
 642                        reg_ctrl = flexcan_read(&mb->can_ctrl);
 643                } while (reg_ctrl & FLEXCAN_MB_CODE_RX_BUSY_BIT);
 644
 645                /* is this MB empty? */
 646                code = reg_ctrl & FLEXCAN_MB_CODE_MASK;
 647                if ((code != FLEXCAN_MB_CODE_RX_FULL) &&
 648                    (code != FLEXCAN_MB_CODE_RX_OVERRUN))
 649                        return 0;
 650
 651                if (code == FLEXCAN_MB_CODE_RX_OVERRUN) {
 652                        /* This MB was overrun, we lost data */
 653                        offload->dev->stats.rx_over_errors++;
 654                        offload->dev->stats.rx_errors++;
 655                }
 656        } else {
 657                reg_iflag1 = flexcan_read(&regs->iflag1);
 658                if (!(reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE))
 659                        return 0;
 660
 661                reg_ctrl = flexcan_read(&mb->can_ctrl);
 662        }
 663
 664        /* increase timstamp to full 32 bit */
 665        *timestamp = reg_ctrl << 16;
 666
 667        reg_id = flexcan_read(&mb->can_id);
 668        if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
 669                cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
 670        else
 671                cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
 672
 673        if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
 674                cf->can_id |= CAN_RTR_FLAG;
 675        cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
 676
 677        *(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
 678        *(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
 679
 680        /* mark as read */
 681        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 682                /* Clear IRQ */
 683                if (n < 32)
 684                        flexcan_write(BIT(n), &regs->iflag1);
 685                else
 686                        flexcan_write(BIT(n - 32), &regs->iflag2);
 687        } else {
 688                flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
 689                flexcan_read(&regs->timer);
 690        }
 691
 692        return 1;
 693}
 694
 695
 696static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
 697{
 698        struct flexcan_regs __iomem *regs = priv->regs;
 699        u32 iflag1, iflag2;
 700
 701        iflag2 = flexcan_read(&regs->iflag2) & priv->reg_imask2_default;
 702        iflag1 = flexcan_read(&regs->iflag1) & priv->reg_imask1_default &
 703                ~FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
 704
 705        return (u64)iflag2 << 32 | iflag1;
 706}
 707
 708static irqreturn_t flexcan_irq(int irq, void *dev_id)
 709{
 710        struct net_device *dev = dev_id;
 711        struct net_device_stats *stats = &dev->stats;
 712        struct flexcan_priv *priv = netdev_priv(dev);
 713        struct flexcan_regs __iomem *regs = priv->regs;
 714        irqreturn_t handled = IRQ_NONE;
 715        u32 reg_iflag1, reg_esr;
 716
 717        reg_iflag1 = flexcan_read(&regs->iflag1);
 718
 719        /* reception interrupt */
 720        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 721                u64 reg_iflag;
 722                int ret;
 723
 724                while ((reg_iflag = flexcan_read_reg_iflag_rx(priv))) {
 725                        handled = IRQ_HANDLED;
 726                        ret = can_rx_offload_irq_offload_timestamp(&priv->offload,
 727                                                                   reg_iflag);
 728                        if (!ret)
 729                                break;
 730                }
 731        } else {
 732                if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) {
 733                        handled = IRQ_HANDLED;
 734                        can_rx_offload_irq_offload_fifo(&priv->offload);
 735                }
 736
 737                /* FIFO overflow interrupt */
 738                if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
 739                        handled = IRQ_HANDLED;
 740                        flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
 741                        dev->stats.rx_over_errors++;
 742                        dev->stats.rx_errors++;
 743                }
 744        }
 745
 746        /* transmission complete interrupt */
 747        if (reg_iflag1 & FLEXCAN_IFLAG_MB(priv->tx_mb_idx)) {
 748                handled = IRQ_HANDLED;
 749                stats->tx_bytes += can_get_echo_skb(dev, 0);
 750                stats->tx_packets++;
 751                can_led_event(dev, CAN_LED_EVENT_TX);
 752
 753                /* after sending a RTR frame MB is in RX mode */
 754                flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 755                              &priv->tx_mb->can_ctrl);
 756                flexcan_write(FLEXCAN_IFLAG_MB(priv->tx_mb_idx), &regs->iflag1);
 757                netif_wake_queue(dev);
 758        }
 759
 760        reg_esr = flexcan_read(&regs->esr);
 761
 762        /* ACK all bus error and state change IRQ sources */
 763        if (reg_esr & FLEXCAN_ESR_ALL_INT) {
 764                handled = IRQ_HANDLED;
 765                flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
 766        }
 767
 768        /* state change interrupt */
 769        if (reg_esr & FLEXCAN_ESR_ERR_STATE)
 770                flexcan_irq_state(dev, reg_esr);
 771
 772        /* bus error IRQ - handle if bus error reporting is activated */
 773        if ((reg_esr & FLEXCAN_ESR_ERR_BUS) &&
 774            (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING))
 775                flexcan_irq_bus_err(dev, reg_esr);
 776
 777        return handled;
 778}
 779
 780static void flexcan_set_bittiming(struct net_device *dev)
 781{
 782        const struct flexcan_priv *priv = netdev_priv(dev);
 783        const struct can_bittiming *bt = &priv->can.bittiming;
 784        struct flexcan_regs __iomem *regs = priv->regs;
 785        u32 reg;
 786
 787        reg = flexcan_read(&regs->ctrl);
 788        reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
 789                 FLEXCAN_CTRL_RJW(0x3) |
 790                 FLEXCAN_CTRL_PSEG1(0x7) |
 791                 FLEXCAN_CTRL_PSEG2(0x7) |
 792                 FLEXCAN_CTRL_PROPSEG(0x7) |
 793                 FLEXCAN_CTRL_LPB |
 794                 FLEXCAN_CTRL_SMP |
 795                 FLEXCAN_CTRL_LOM);
 796
 797        reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
 798                FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
 799                FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
 800                FLEXCAN_CTRL_RJW(bt->sjw - 1) |
 801                FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
 802
 803        if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 804                reg |= FLEXCAN_CTRL_LPB;
 805        if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 806                reg |= FLEXCAN_CTRL_LOM;
 807        if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 808                reg |= FLEXCAN_CTRL_SMP;
 809
 810        netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
 811        flexcan_write(reg, &regs->ctrl);
 812
 813        /* print chip status */
 814        netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
 815                   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 816}
 817
 818/* flexcan_chip_start
 819 *
 820 * this functions is entered with clocks enabled
 821 *
 822 */
 823static int flexcan_chip_start(struct net_device *dev)
 824{
 825        struct flexcan_priv *priv = netdev_priv(dev);
 826        struct flexcan_regs __iomem *regs = priv->regs;
 827        u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
 828        int err, i;
 829
 830        /* enable module */
 831        err = flexcan_chip_enable(priv);
 832        if (err)
 833                return err;
 834
 835        /* soft reset */
 836        err = flexcan_chip_softreset(priv);
 837        if (err)
 838                goto out_chip_disable;
 839
 840        flexcan_set_bittiming(dev);
 841
 842        /* MCR
 843         *
 844         * enable freeze
 845         * enable fifo
 846         * halt now
 847         * only supervisor access
 848         * enable warning int
 849         * disable local echo
 850         * enable individual RX masking
 851         * choose format C
 852         * set max mailbox number
 853         */
 854        reg_mcr = flexcan_read(&regs->mcr);
 855        reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
 856        reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |
 857                FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS | FLEXCAN_MCR_IRMQ |
 858                FLEXCAN_MCR_IDAM_C;
 859
 860        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 861                reg_mcr &= ~FLEXCAN_MCR_FEN;
 862                reg_mcr |= FLEXCAN_MCR_MAXMB(priv->offload.mb_last);
 863        } else {
 864                reg_mcr |= FLEXCAN_MCR_FEN |
 865                        FLEXCAN_MCR_MAXMB(priv->tx_mb_idx);
 866        }
 867        netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
 868        flexcan_write(reg_mcr, &regs->mcr);
 869
 870        /* CTRL
 871         *
 872         * disable timer sync feature
 873         *
 874         * disable auto busoff recovery
 875         * transmit lowest buffer first
 876         *
 877         * enable tx and rx warning interrupt
 878         * enable bus off interrupt
 879         * (== FLEXCAN_CTRL_ERR_STATE)
 880         */
 881        reg_ctrl = flexcan_read(&regs->ctrl);
 882        reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
 883        reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
 884                FLEXCAN_CTRL_ERR_STATE;
 885
 886        /* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
 887         * on most Flexcan cores, too. Otherwise we don't get
 888         * any error warning or passive interrupts.
 889         */
 890        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_ERR_STATE ||
 891            priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
 892                reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
 893        else
 894                reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
 895
 896        /* save for later use */
 897        priv->reg_ctrl_default = reg_ctrl;
 898        /* leave interrupts disabled for now */
 899        reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
 900        netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
 901        flexcan_write(reg_ctrl, &regs->ctrl);
 902
 903        if ((priv->devtype_data->quirks & FLEXCAN_QUIRK_ENABLE_EACEN_RRS)) {
 904                reg_ctrl2 = flexcan_read(&regs->ctrl2);
 905                reg_ctrl2 |= FLEXCAN_CTRL2_EACEN | FLEXCAN_CTRL2_RRS;
 906                flexcan_write(reg_ctrl2, &regs->ctrl2);
 907        }
 908
 909        /* clear and invalidate all mailboxes first */
 910        for (i = priv->tx_mb_idx; i < ARRAY_SIZE(regs->mb); i++) {
 911                flexcan_write(FLEXCAN_MB_CODE_RX_INACTIVE,
 912                              &regs->mb[i].can_ctrl);
 913        }
 914
 915        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
 916                for (i = priv->offload.mb_first; i <= priv->offload.mb_last; i++)
 917                        flexcan_write(FLEXCAN_MB_CODE_RX_EMPTY,
 918                                      &regs->mb[i].can_ctrl);
 919        }
 920
 921        /* Errata ERR005829: mark first TX mailbox as INACTIVE */
 922        flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 923                      &priv->tx_mb_reserved->can_ctrl);
 924
 925        /* mark TX mailbox as INACTIVE */
 926        flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 927                      &priv->tx_mb->can_ctrl);
 928
 929        /* acceptance mask/acceptance code (accept everything) */
 930        flexcan_write(0x0, &regs->rxgmask);
 931        flexcan_write(0x0, &regs->rx14mask);
 932        flexcan_write(0x0, &regs->rx15mask);
 933
 934        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
 935                flexcan_write(0x0, &regs->rxfgmask);
 936
 937        /* clear acceptance filters */
 938        for (i = 0; i < ARRAY_SIZE(regs->mb); i++)
 939                flexcan_write(0, &regs->rximr[i]);
 940
 941        /* On Vybrid, disable memory error detection interrupts
 942         * and freeze mode.
 943         * This also works around errata e5295 which generates
 944         * false positive memory errors and put the device in
 945         * freeze mode.
 946         */
 947        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
 948                /* Follow the protocol as described in "Detection
 949                 * and Correction of Memory Errors" to write to
 950                 * MECR register
 951                 */
 952                reg_ctrl2 = flexcan_read(&regs->ctrl2);
 953                reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
 954                flexcan_write(reg_ctrl2, &regs->ctrl2);
 955
 956                reg_mecr = flexcan_read(&regs->mecr);
 957                reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
 958                flexcan_write(reg_mecr, &regs->mecr);
 959                reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
 960                              FLEXCAN_MECR_FANCEI_MSK);
 961                flexcan_write(reg_mecr, &regs->mecr);
 962        }
 963
 964        err = flexcan_transceiver_enable(priv);
 965        if (err)
 966                goto out_chip_disable;
 967
 968        /* synchronize with the can bus */
 969        err = flexcan_chip_unfreeze(priv);
 970        if (err)
 971                goto out_transceiver_disable;
 972
 973        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 974
 975        /* enable interrupts atomically */
 976        disable_irq(dev->irq);
 977        flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
 978        flexcan_write(priv->reg_imask1_default, &regs->imask1);
 979        flexcan_write(priv->reg_imask2_default, &regs->imask2);
 980        enable_irq(dev->irq);
 981
 982        /* print chip status */
 983        netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
 984                   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 985
 986        return 0;
 987
 988 out_transceiver_disable:
 989        flexcan_transceiver_disable(priv);
 990 out_chip_disable:
 991        flexcan_chip_disable(priv);
 992        return err;
 993}
 994
 995/* flexcan_chip_stop
 996 *
 997 * this functions is entered with clocks enabled
 998 */
 999static void flexcan_chip_stop(struct net_device *dev)
1000{
1001        struct flexcan_priv *priv = netdev_priv(dev);
1002        struct flexcan_regs __iomem *regs = priv->regs;
1003
1004        /* freeze + disable module */
1005        flexcan_chip_freeze(priv);
1006        flexcan_chip_disable(priv);
1007
1008        /* Disable all interrupts */
1009        flexcan_write(0, &regs->imask2);
1010        flexcan_write(0, &regs->imask1);
1011        flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
1012                      &regs->ctrl);
1013
1014        flexcan_transceiver_disable(priv);
1015        priv->can.state = CAN_STATE_STOPPED;
1016}
1017
1018static int flexcan_open(struct net_device *dev)
1019{
1020        struct flexcan_priv *priv = netdev_priv(dev);
1021        int err;
1022
1023        err = clk_prepare_enable(priv->clk_ipg);
1024        if (err)
1025                return err;
1026
1027        err = clk_prepare_enable(priv->clk_per);
1028        if (err)
1029                goto out_disable_ipg;
1030
1031        err = open_candev(dev);
1032        if (err)
1033                goto out_disable_per;
1034
1035        err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
1036        if (err)
1037                goto out_close;
1038
1039        /* start chip and queuing */
1040        err = flexcan_chip_start(dev);
1041        if (err)
1042                goto out_free_irq;
1043
1044        can_led_event(dev, CAN_LED_EVENT_OPEN);
1045
1046        can_rx_offload_enable(&priv->offload);
1047        netif_start_queue(dev);
1048
1049        return 0;
1050
1051 out_free_irq:
1052        free_irq(dev->irq, dev);
1053 out_close:
1054        close_candev(dev);
1055 out_disable_per:
1056        clk_disable_unprepare(priv->clk_per);
1057 out_disable_ipg:
1058        clk_disable_unprepare(priv->clk_ipg);
1059
1060        return err;
1061}
1062
1063static int flexcan_close(struct net_device *dev)
1064{
1065        struct flexcan_priv *priv = netdev_priv(dev);
1066
1067        netif_stop_queue(dev);
1068        can_rx_offload_disable(&priv->offload);
1069        flexcan_chip_stop(dev);
1070
1071        free_irq(dev->irq, dev);
1072        clk_disable_unprepare(priv->clk_per);
1073        clk_disable_unprepare(priv->clk_ipg);
1074
1075        close_candev(dev);
1076
1077        can_led_event(dev, CAN_LED_EVENT_STOP);
1078
1079        return 0;
1080}
1081
1082static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
1083{
1084        int err;
1085
1086        switch (mode) {
1087        case CAN_MODE_START:
1088                err = flexcan_chip_start(dev);
1089                if (err)
1090                        return err;
1091
1092                netif_wake_queue(dev);
1093                break;
1094
1095        default:
1096                return -EOPNOTSUPP;
1097        }
1098
1099        return 0;
1100}
1101
1102static const struct net_device_ops flexcan_netdev_ops = {
1103        .ndo_open       = flexcan_open,
1104        .ndo_stop       = flexcan_close,
1105        .ndo_start_xmit = flexcan_start_xmit,
1106        .ndo_change_mtu = can_change_mtu,
1107};
1108
1109static int register_flexcandev(struct net_device *dev)
1110{
1111        struct flexcan_priv *priv = netdev_priv(dev);
1112        struct flexcan_regs __iomem *regs = priv->regs;
1113        u32 reg, err;
1114
1115        err = clk_prepare_enable(priv->clk_ipg);
1116        if (err)
1117                return err;
1118
1119        err = clk_prepare_enable(priv->clk_per);
1120        if (err)
1121                goto out_disable_ipg;
1122
1123        /* select "bus clock", chip must be disabled */
1124        err = flexcan_chip_disable(priv);
1125        if (err)
1126                goto out_disable_per;
1127        reg = flexcan_read(&regs->ctrl);
1128        reg |= FLEXCAN_CTRL_CLK_SRC;
1129        flexcan_write(reg, &regs->ctrl);
1130
1131        err = flexcan_chip_enable(priv);
1132        if (err)
1133                goto out_chip_disable;
1134
1135        /* set freeze, halt and activate FIFO, restrict register access */
1136        reg = flexcan_read(&regs->mcr);
1137        reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
1138                FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
1139        flexcan_write(reg, &regs->mcr);
1140
1141        /* Currently we only support newer versions of this core
1142         * featuring a RX hardware FIFO (although this driver doesn't
1143         * make use of it on some cores). Older cores, found on some
1144         * Coldfire derivates are not tested.
1145         */
1146        reg = flexcan_read(&regs->mcr);
1147        if (!(reg & FLEXCAN_MCR_FEN)) {
1148                netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
1149                err = -ENODEV;
1150                goto out_chip_disable;
1151        }
1152
1153        err = register_candev(dev);
1154
1155        /* disable core and turn off clocks */
1156 out_chip_disable:
1157        flexcan_chip_disable(priv);
1158 out_disable_per:
1159        clk_disable_unprepare(priv->clk_per);
1160 out_disable_ipg:
1161        clk_disable_unprepare(priv->clk_ipg);
1162
1163        return err;
1164}
1165
1166static void unregister_flexcandev(struct net_device *dev)
1167{
1168        unregister_candev(dev);
1169}
1170
1171static const struct of_device_id flexcan_of_match[] = {
1172        { .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
1173        { .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
1174        { .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
1175        { .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
1176        { /* sentinel */ },
1177};
1178MODULE_DEVICE_TABLE(of, flexcan_of_match);
1179
1180static const struct platform_device_id flexcan_id_table[] = {
1181        { .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
1182        { /* sentinel */ },
1183};
1184MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1185
1186static int flexcan_probe(struct platform_device *pdev)
1187{
1188        const struct of_device_id *of_id;
1189        const struct flexcan_devtype_data *devtype_data;
1190        struct net_device *dev;
1191        struct flexcan_priv *priv;
1192        struct regulator *reg_xceiver;
1193        struct resource *mem;
1194        struct clk *clk_ipg = NULL, *clk_per = NULL;
1195        struct flexcan_regs __iomem *regs;
1196        int err, irq;
1197        u32 clock_freq = 0;
1198
1199        reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1200        if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
1201                return -EPROBE_DEFER;
1202        else if (IS_ERR(reg_xceiver))
1203                reg_xceiver = NULL;
1204
1205        if (pdev->dev.of_node)
1206                of_property_read_u32(pdev->dev.of_node,
1207                                     "clock-frequency", &clock_freq);
1208
1209        if (!clock_freq) {
1210                clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1211                if (IS_ERR(clk_ipg)) {
1212                        dev_err(&pdev->dev, "no ipg clock defined\n");
1213                        return PTR_ERR(clk_ipg);
1214                }
1215
1216                clk_per = devm_clk_get(&pdev->dev, "per");
1217                if (IS_ERR(clk_per)) {
1218                        dev_err(&pdev->dev, "no per clock defined\n");
1219                        return PTR_ERR(clk_per);
1220                }
1221                clock_freq = clk_get_rate(clk_per);
1222        }
1223
1224        mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1225        irq = platform_get_irq(pdev, 0);
1226        if (irq <= 0)
1227                return -ENODEV;
1228
1229        regs = devm_ioremap_resource(&pdev->dev, mem);
1230        if (IS_ERR(regs))
1231                return PTR_ERR(regs);
1232
1233        of_id = of_match_device(flexcan_of_match, &pdev->dev);
1234        if (of_id) {
1235                devtype_data = of_id->data;
1236        } else if (platform_get_device_id(pdev)->driver_data) {
1237                devtype_data = (struct flexcan_devtype_data *)
1238                        platform_get_device_id(pdev)->driver_data;
1239        } else {
1240                return -ENODEV;
1241        }
1242
1243        dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1244        if (!dev)
1245                return -ENOMEM;
1246
1247        platform_set_drvdata(pdev, dev);
1248        SET_NETDEV_DEV(dev, &pdev->dev);
1249
1250        dev->netdev_ops = &flexcan_netdev_ops;
1251        dev->irq = irq;
1252        dev->flags |= IFF_ECHO;
1253
1254        priv = netdev_priv(dev);
1255        priv->can.clock.freq = clock_freq;
1256        priv->can.bittiming_const = &flexcan_bittiming_const;
1257        priv->can.do_set_mode = flexcan_set_mode;
1258        priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1259        priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1260                CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_3_SAMPLES |
1261                CAN_CTRLMODE_BERR_REPORTING;
1262        priv->regs = regs;
1263        priv->clk_ipg = clk_ipg;
1264        priv->clk_per = clk_per;
1265        priv->devtype_data = devtype_data;
1266        priv->reg_xceiver = reg_xceiver;
1267
1268        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
1269                priv->tx_mb_idx = FLEXCAN_TX_MB_OFF_TIMESTAMP;
1270                priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
1271        } else {
1272                priv->tx_mb_idx = FLEXCAN_TX_MB_OFF_FIFO;
1273                priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
1274        }
1275        priv->tx_mb = &regs->mb[priv->tx_mb_idx];
1276
1277        priv->reg_imask1_default = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
1278        priv->reg_imask2_default = 0;
1279
1280        priv->offload.mailbox_read = flexcan_mailbox_read;
1281
1282        if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP) {
1283                u64 imask;
1284
1285                priv->offload.mb_first = FLEXCAN_RX_MB_OFF_TIMESTAMP_FIRST;
1286                priv->offload.mb_last = FLEXCAN_RX_MB_OFF_TIMESTAMP_LAST;
1287
1288                imask = GENMASK_ULL(priv->offload.mb_last, priv->offload.mb_first);
1289                priv->reg_imask1_default |= imask;
1290                priv->reg_imask2_default |= imask >> 32;
1291
1292                err = can_rx_offload_add_timestamp(dev, &priv->offload);
1293        } else {
1294                priv->reg_imask1_default |= FLEXCAN_IFLAG_RX_FIFO_OVERFLOW |
1295                        FLEXCAN_IFLAG_RX_FIFO_AVAILABLE;
1296                err = can_rx_offload_add_fifo(dev, &priv->offload, FLEXCAN_NAPI_WEIGHT);
1297        }
1298        if (err)
1299                goto failed_offload;
1300
1301        err = register_flexcandev(dev);
1302        if (err) {
1303                dev_err(&pdev->dev, "registering netdev failed\n");
1304                goto failed_register;
1305        }
1306
1307        devm_can_led_init(dev);
1308
1309        dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1310                 priv->regs, dev->irq);
1311
1312        return 0;
1313
1314 failed_offload:
1315 failed_register:
1316        free_candev(dev);
1317        return err;
1318}
1319
1320static int flexcan_remove(struct platform_device *pdev)
1321{
1322        struct net_device *dev = platform_get_drvdata(pdev);
1323        struct flexcan_priv *priv = netdev_priv(dev);
1324
1325        unregister_flexcandev(dev);
1326        can_rx_offload_del(&priv->offload);
1327        free_candev(dev);
1328
1329        return 0;
1330}
1331
1332static int __maybe_unused flexcan_suspend(struct device *device)
1333{
1334        struct net_device *dev = dev_get_drvdata(device);
1335        struct flexcan_priv *priv = netdev_priv(dev);
1336        int err;
1337
1338        if (netif_running(dev)) {
1339                err = flexcan_chip_disable(priv);
1340                if (err)
1341                        return err;
1342                netif_stop_queue(dev);
1343                netif_device_detach(dev);
1344        }
1345        priv->can.state = CAN_STATE_SLEEPING;
1346
1347        return 0;
1348}
1349
1350static int __maybe_unused flexcan_resume(struct device *device)
1351{
1352        struct net_device *dev = dev_get_drvdata(device);
1353        struct flexcan_priv *priv = netdev_priv(dev);
1354        int err;
1355
1356        priv->can.state = CAN_STATE_ERROR_ACTIVE;
1357        if (netif_running(dev)) {
1358                netif_device_attach(dev);
1359                netif_start_queue(dev);
1360                err = flexcan_chip_enable(priv);
1361                if (err)
1362                        return err;
1363        }
1364        return 0;
1365}
1366
1367static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
1368
1369static struct platform_driver flexcan_driver = {
1370        .driver = {
1371                .name = DRV_NAME,
1372                .pm = &flexcan_pm_ops,
1373                .of_match_table = flexcan_of_match,
1374        },
1375        .probe = flexcan_probe,
1376        .remove = flexcan_remove,
1377        .id_table = flexcan_id_table,
1378};
1379
1380module_platform_driver(flexcan_driver);
1381
1382MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1383              "Marc Kleine-Budde <kernel@pengutronix.de>");
1384MODULE_LICENSE("GPL v2");
1385MODULE_DESCRIPTION("CAN port driver for flexcan based chip");
1386