linux/drivers/net/can/spi/mcp251x.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
   3 *
   4 * MCP2510 support and bug fixes by Christian Pellegrin
   5 * <chripell@evolware.org>
   6 *
   7 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
   8 *
   9 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
  10 * Written under contract by:
  11 *   Chris Elston, Katalix Systems, Ltd.
  12 *
  13 * Based on Microchip MCP251x CAN controller driver written by
  14 * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
  15 *
  16 * Based on CAN bus driver for the CCAN controller written by
  17 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
  18 * - Simon Kallweit, intefo AG
  19 * Copyright 2007
  20 */
  21
  22#include <linux/bitfield.h>
  23#include <linux/can/core.h>
  24#include <linux/can/dev.h>
  25#include <linux/can/led.h>
  26#include <linux/clk.h>
  27#include <linux/completion.h>
  28#include <linux/delay.h>
  29#include <linux/device.h>
  30#include <linux/freezer.h>
  31#include <linux/gpio.h>
  32#include <linux/gpio/driver.h>
  33#include <linux/interrupt.h>
  34#include <linux/io.h>
  35#include <linux/iopoll.h>
  36#include <linux/kernel.h>
  37#include <linux/module.h>
  38#include <linux/netdevice.h>
  39#include <linux/platform_device.h>
  40#include <linux/property.h>
  41#include <linux/regulator/consumer.h>
  42#include <linux/slab.h>
  43#include <linux/spi/spi.h>
  44#include <linux/uaccess.h>
  45
  46/* SPI interface instruction set */
  47#define INSTRUCTION_WRITE       0x02
  48#define INSTRUCTION_READ        0x03
  49#define INSTRUCTION_BIT_MODIFY  0x05
  50#define INSTRUCTION_LOAD_TXB(n) (0x40 + 2 * (n))
  51#define INSTRUCTION_READ_RXB(n) (((n) == 0) ? 0x90 : 0x94)
  52#define INSTRUCTION_RESET       0xC0
  53#define RTS_TXB0                0x01
  54#define RTS_TXB1                0x02
  55#define RTS_TXB2                0x04
  56#define INSTRUCTION_RTS(n)      (0x80 | ((n) & 0x07))
  57
  58/* MPC251x registers */
  59#define BFPCTRL                 0x0c
  60#  define BFPCTRL_B0BFM         BIT(0)
  61#  define BFPCTRL_B1BFM         BIT(1)
  62#  define BFPCTRL_BFM(n)        (BFPCTRL_B0BFM << (n))
  63#  define BFPCTRL_BFM_MASK      GENMASK(1, 0)
  64#  define BFPCTRL_B0BFE         BIT(2)
  65#  define BFPCTRL_B1BFE         BIT(3)
  66#  define BFPCTRL_BFE(n)        (BFPCTRL_B0BFE << (n))
  67#  define BFPCTRL_BFE_MASK      GENMASK(3, 2)
  68#  define BFPCTRL_B0BFS         BIT(4)
  69#  define BFPCTRL_B1BFS         BIT(5)
  70#  define BFPCTRL_BFS(n)        (BFPCTRL_B0BFS << (n))
  71#  define BFPCTRL_BFS_MASK      GENMASK(5, 4)
  72#define TXRTSCTRL               0x0d
  73#  define TXRTSCTRL_B0RTSM      BIT(0)
  74#  define TXRTSCTRL_B1RTSM      BIT(1)
  75#  define TXRTSCTRL_B2RTSM      BIT(2)
  76#  define TXRTSCTRL_RTSM(n)     (TXRTSCTRL_B0RTSM << (n))
  77#  define TXRTSCTRL_RTSM_MASK   GENMASK(2, 0)
  78#  define TXRTSCTRL_B0RTS       BIT(3)
  79#  define TXRTSCTRL_B1RTS       BIT(4)
  80#  define TXRTSCTRL_B2RTS       BIT(5)
  81#  define TXRTSCTRL_RTS(n)      (TXRTSCTRL_B0RTS << (n))
  82#  define TXRTSCTRL_RTS_MASK    GENMASK(5, 3)
  83#define CANSTAT       0x0e
  84#define CANCTRL       0x0f
  85#  define CANCTRL_REQOP_MASK        0xe0
  86#  define CANCTRL_REQOP_CONF        0x80
  87#  define CANCTRL_REQOP_LISTEN_ONLY 0x60
  88#  define CANCTRL_REQOP_LOOPBACK    0x40
  89#  define CANCTRL_REQOP_SLEEP       0x20
  90#  define CANCTRL_REQOP_NORMAL      0x00
  91#  define CANCTRL_OSM               0x08
  92#  define CANCTRL_ABAT              0x10
  93#define TEC           0x1c
  94#define REC           0x1d
  95#define CNF1          0x2a
  96#  define CNF1_SJW_SHIFT   6
  97#define CNF2          0x29
  98#  define CNF2_BTLMODE     0x80
  99#  define CNF2_SAM         0x40
 100#  define CNF2_PS1_SHIFT   3
 101#define CNF3          0x28
 102#  define CNF3_SOF         0x08
 103#  define CNF3_WAKFIL      0x04
 104#  define CNF3_PHSEG2_MASK 0x07
 105#define CANINTE       0x2b
 106#  define CANINTE_MERRE 0x80
 107#  define CANINTE_WAKIE 0x40
 108#  define CANINTE_ERRIE 0x20
 109#  define CANINTE_TX2IE 0x10
 110#  define CANINTE_TX1IE 0x08
 111#  define CANINTE_TX0IE 0x04
 112#  define CANINTE_RX1IE 0x02
 113#  define CANINTE_RX0IE 0x01
 114#define CANINTF       0x2c
 115#  define CANINTF_MERRF 0x80
 116#  define CANINTF_WAKIF 0x40
 117#  define CANINTF_ERRIF 0x20
 118#  define CANINTF_TX2IF 0x10
 119#  define CANINTF_TX1IF 0x08
 120#  define CANINTF_TX0IF 0x04
 121#  define CANINTF_RX1IF 0x02
 122#  define CANINTF_RX0IF 0x01
 123#  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
 124#  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
 125#  define CANINTF_ERR (CANINTF_ERRIF)
 126#define EFLG          0x2d
 127#  define EFLG_EWARN    0x01
 128#  define EFLG_RXWAR    0x02
 129#  define EFLG_TXWAR    0x04
 130#  define EFLG_RXEP     0x08
 131#  define EFLG_TXEP     0x10
 132#  define EFLG_TXBO     0x20
 133#  define EFLG_RX0OVR   0x40
 134#  define EFLG_RX1OVR   0x80
 135#define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
 136#  define TXBCTRL_ABTF  0x40
 137#  define TXBCTRL_MLOA  0x20
 138#  define TXBCTRL_TXERR 0x10
 139#  define TXBCTRL_TXREQ 0x08
 140#define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
 141#  define SIDH_SHIFT    3
 142#define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
 143#  define SIDL_SID_MASK    7
 144#  define SIDL_SID_SHIFT   5
 145#  define SIDL_EXIDE_SHIFT 3
 146#  define SIDL_EID_SHIFT   16
 147#  define SIDL_EID_MASK    3
 148#define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
 149#define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
 150#define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
 151#  define DLC_RTR_SHIFT    6
 152#define TXBCTRL_OFF 0
 153#define TXBSIDH_OFF 1
 154#define TXBSIDL_OFF 2
 155#define TXBEID8_OFF 3
 156#define TXBEID0_OFF 4
 157#define TXBDLC_OFF  5
 158#define TXBDAT_OFF  6
 159#define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
 160#  define RXBCTRL_BUKT  0x04
 161#  define RXBCTRL_RXM0  0x20
 162#  define RXBCTRL_RXM1  0x40
 163#define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
 164#  define RXBSIDH_SHIFT 3
 165#define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
 166#  define RXBSIDL_IDE   0x08
 167#  define RXBSIDL_SRR   0x10
 168#  define RXBSIDL_EID   3
 169#  define RXBSIDL_SHIFT 5
 170#define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
 171#define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
 172#define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
 173#  define RXBDLC_LEN_MASK  0x0f
 174#  define RXBDLC_RTR       0x40
 175#define RXBCTRL_OFF 0
 176#define RXBSIDH_OFF 1
 177#define RXBSIDL_OFF 2
 178#define RXBEID8_OFF 3
 179#define RXBEID0_OFF 4
 180#define RXBDLC_OFF  5
 181#define RXBDAT_OFF  6
 182#define RXFSID(n) ((n < 3) ? 0 : 4)
 183#define RXFSIDH(n) ((n) * 4 + RXFSID(n))
 184#define RXFSIDL(n) ((n) * 4 + 1 + RXFSID(n))
 185#define RXFEID8(n) ((n) * 4 + 2 + RXFSID(n))
 186#define RXFEID0(n) ((n) * 4 + 3 + RXFSID(n))
 187#define RXMSIDH(n) ((n) * 4 + 0x20)
 188#define RXMSIDL(n) ((n) * 4 + 0x21)
 189#define RXMEID8(n) ((n) * 4 + 0x22)
 190#define RXMEID0(n) ((n) * 4 + 0x23)
 191
 192#define GET_BYTE(val, byte)                     \
 193        (((val) >> ((byte) * 8)) & 0xff)
 194#define SET_BYTE(val, byte)                     \
 195        (((val) & 0xff) << ((byte) * 8))
 196
 197/* Buffer size required for the largest SPI transfer (i.e., reading a
 198 * frame)
 199 */
 200#define CAN_FRAME_MAX_DATA_LEN  8
 201#define SPI_TRANSFER_BUF_LEN    (6 + CAN_FRAME_MAX_DATA_LEN)
 202#define CAN_FRAME_MAX_BITS      128
 203
 204#define TX_ECHO_SKB_MAX 1
 205
 206#define MCP251X_OST_DELAY_MS    (5)
 207
 208#define DEVICE_NAME "mcp251x"
 209
 210static const struct can_bittiming_const mcp251x_bittiming_const = {
 211        .name = DEVICE_NAME,
 212        .tseg1_min = 3,
 213        .tseg1_max = 16,
 214        .tseg2_min = 2,
 215        .tseg2_max = 8,
 216        .sjw_max = 4,
 217        .brp_min = 1,
 218        .brp_max = 64,
 219        .brp_inc = 1,
 220};
 221
 222enum mcp251x_model {
 223        CAN_MCP251X_MCP2510     = 0x2510,
 224        CAN_MCP251X_MCP2515     = 0x2515,
 225        CAN_MCP251X_MCP25625    = 0x25625,
 226};
 227
 228struct mcp251x_priv {
 229        struct can_priv    can;
 230        struct net_device *net;
 231        struct spi_device *spi;
 232        enum mcp251x_model model;
 233
 234        struct mutex mcp_lock; /* SPI device lock */
 235
 236        u8 *spi_tx_buf;
 237        u8 *spi_rx_buf;
 238
 239        struct sk_buff *tx_skb;
 240        int tx_len;
 241
 242        struct workqueue_struct *wq;
 243        struct work_struct tx_work;
 244        struct work_struct restart_work;
 245
 246        int force_quit;
 247        int after_suspend;
 248#define AFTER_SUSPEND_UP 1
 249#define AFTER_SUSPEND_DOWN 2
 250#define AFTER_SUSPEND_POWER 4
 251#define AFTER_SUSPEND_RESTART 8
 252        int restart_tx;
 253        struct regulator *power;
 254        struct regulator *transceiver;
 255        struct clk *clk;
 256#ifdef CONFIG_GPIOLIB
 257        struct gpio_chip gpio;
 258        u8 reg_bfpctrl;
 259#endif
 260};
 261
 262#define MCP251X_IS(_model) \
 263static inline int mcp251x_is_##_model(struct spi_device *spi) \
 264{ \
 265        struct mcp251x_priv *priv = spi_get_drvdata(spi); \
 266        return priv->model == CAN_MCP251X_MCP##_model; \
 267}
 268
 269MCP251X_IS(2510);
 270
 271static void mcp251x_clean(struct net_device *net)
 272{
 273        struct mcp251x_priv *priv = netdev_priv(net);
 274
 275        if (priv->tx_skb || priv->tx_len)
 276                net->stats.tx_errors++;
 277        dev_kfree_skb(priv->tx_skb);
 278        if (priv->tx_len)
 279                can_free_echo_skb(priv->net, 0, NULL);
 280        priv->tx_skb = NULL;
 281        priv->tx_len = 0;
 282}
 283
 284/* Note about handling of error return of mcp251x_spi_trans: accessing
 285 * registers via SPI is not really different conceptually than using
 286 * normal I/O assembler instructions, although it's much more
 287 * complicated from a practical POV. So it's not advisable to always
 288 * check the return value of this function. Imagine that every
 289 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
 290 * error();", it would be a great mess (well there are some situation
 291 * when exception handling C++ like could be useful after all). So we
 292 * just check that transfers are OK at the beginning of our
 293 * conversation with the chip and to avoid doing really nasty things
 294 * (like injecting bogus packets in the network stack).
 295 */
 296static int mcp251x_spi_trans(struct spi_device *spi, int len)
 297{
 298        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 299        struct spi_transfer t = {
 300                .tx_buf = priv->spi_tx_buf,
 301                .rx_buf = priv->spi_rx_buf,
 302                .len = len,
 303                .cs_change = 0,
 304        };
 305        struct spi_message m;
 306        int ret;
 307
 308        spi_message_init(&m);
 309        spi_message_add_tail(&t, &m);
 310
 311        ret = spi_sync(spi, &m);
 312        if (ret)
 313                dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
 314        return ret;
 315}
 316
 317static int mcp251x_spi_write(struct spi_device *spi, int len)
 318{
 319        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 320        int ret;
 321
 322        ret = spi_write(spi, priv->spi_tx_buf, len);
 323        if (ret)
 324                dev_err(&spi->dev, "spi write failed: ret = %d\n", ret);
 325
 326        return ret;
 327}
 328
 329static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg)
 330{
 331        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 332        u8 val = 0;
 333
 334        priv->spi_tx_buf[0] = INSTRUCTION_READ;
 335        priv->spi_tx_buf[1] = reg;
 336
 337        if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {
 338                spi_write_then_read(spi, priv->spi_tx_buf, 2, &val, 1);
 339        } else {
 340                mcp251x_spi_trans(spi, 3);
 341                val = priv->spi_rx_buf[2];
 342        }
 343
 344        return val;
 345}
 346
 347static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2)
 348{
 349        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 350
 351        priv->spi_tx_buf[0] = INSTRUCTION_READ;
 352        priv->spi_tx_buf[1] = reg;
 353
 354        if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {
 355                u8 val[2] = { 0 };
 356
 357                spi_write_then_read(spi, priv->spi_tx_buf, 2, val, 2);
 358                *v1 = val[0];
 359                *v2 = val[1];
 360        } else {
 361                mcp251x_spi_trans(spi, 4);
 362
 363                *v1 = priv->spi_rx_buf[2];
 364                *v2 = priv->spi_rx_buf[3];
 365        }
 366}
 367
 368static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val)
 369{
 370        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 371
 372        priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
 373        priv->spi_tx_buf[1] = reg;
 374        priv->spi_tx_buf[2] = val;
 375
 376        mcp251x_spi_write(spi, 3);
 377}
 378
 379static void mcp251x_write_2regs(struct spi_device *spi, u8 reg, u8 v1, u8 v2)
 380{
 381        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 382
 383        priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
 384        priv->spi_tx_buf[1] = reg;
 385        priv->spi_tx_buf[2] = v1;
 386        priv->spi_tx_buf[3] = v2;
 387
 388        mcp251x_spi_write(spi, 4);
 389}
 390
 391static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
 392                               u8 mask, u8 val)
 393{
 394        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 395
 396        priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
 397        priv->spi_tx_buf[1] = reg;
 398        priv->spi_tx_buf[2] = mask;
 399        priv->spi_tx_buf[3] = val;
 400
 401        mcp251x_spi_write(spi, 4);
 402}
 403
 404static u8 mcp251x_read_stat(struct spi_device *spi)
 405{
 406        return mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK;
 407}
 408
 409#define mcp251x_read_stat_poll_timeout(addr, val, cond, delay_us, timeout_us) \
 410        readx_poll_timeout(mcp251x_read_stat, addr, val, cond, \
 411                           delay_us, timeout_us)
 412
 413#ifdef CONFIG_GPIOLIB
 414enum {
 415        MCP251X_GPIO_TX0RTS = 0,                /* inputs */
 416        MCP251X_GPIO_TX1RTS,
 417        MCP251X_GPIO_TX2RTS,
 418        MCP251X_GPIO_RX0BF,                     /* outputs */
 419        MCP251X_GPIO_RX1BF,
 420};
 421
 422#define MCP251X_GPIO_INPUT_MASK \
 423        GENMASK(MCP251X_GPIO_TX2RTS, MCP251X_GPIO_TX0RTS)
 424#define MCP251X_GPIO_OUTPUT_MASK \
 425        GENMASK(MCP251X_GPIO_RX1BF, MCP251X_GPIO_RX0BF)
 426
 427static const char * const mcp251x_gpio_names[] = {
 428        [MCP251X_GPIO_TX0RTS] = "TX0RTS",       /* inputs */
 429        [MCP251X_GPIO_TX1RTS] = "TX1RTS",
 430        [MCP251X_GPIO_TX2RTS] = "TX2RTS",
 431        [MCP251X_GPIO_RX0BF] = "RX0BF",         /* outputs */
 432        [MCP251X_GPIO_RX1BF] = "RX1BF",
 433};
 434
 435static inline bool mcp251x_gpio_is_input(unsigned int offset)
 436{
 437        return offset <= MCP251X_GPIO_TX2RTS;
 438}
 439
 440static int mcp251x_gpio_request(struct gpio_chip *chip,
 441                                unsigned int offset)
 442{
 443        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 444        u8 val;
 445
 446        /* nothing to be done for inputs */
 447        if (mcp251x_gpio_is_input(offset))
 448                return 0;
 449
 450        val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);
 451
 452        mutex_lock(&priv->mcp_lock);
 453        mcp251x_write_bits(priv->spi, BFPCTRL, val, val);
 454        mutex_unlock(&priv->mcp_lock);
 455
 456        priv->reg_bfpctrl |= val;
 457
 458        return 0;
 459}
 460
 461static void mcp251x_gpio_free(struct gpio_chip *chip,
 462                              unsigned int offset)
 463{
 464        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 465        u8 val;
 466
 467        /* nothing to be done for inputs */
 468        if (mcp251x_gpio_is_input(offset))
 469                return;
 470
 471        val = BFPCTRL_BFE(offset - MCP251X_GPIO_RX0BF);
 472
 473        mutex_lock(&priv->mcp_lock);
 474        mcp251x_write_bits(priv->spi, BFPCTRL, val, 0);
 475        mutex_unlock(&priv->mcp_lock);
 476
 477        priv->reg_bfpctrl &= ~val;
 478}
 479
 480static int mcp251x_gpio_get_direction(struct gpio_chip *chip,
 481                                      unsigned int offset)
 482{
 483        if (mcp251x_gpio_is_input(offset))
 484                return GPIOF_DIR_IN;
 485
 486        return GPIOF_DIR_OUT;
 487}
 488
 489static int mcp251x_gpio_get(struct gpio_chip *chip, unsigned int offset)
 490{
 491        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 492        u8 reg, mask, val;
 493
 494        if (mcp251x_gpio_is_input(offset)) {
 495                reg = TXRTSCTRL;
 496                mask = TXRTSCTRL_RTS(offset);
 497        } else {
 498                reg = BFPCTRL;
 499                mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);
 500        }
 501
 502        mutex_lock(&priv->mcp_lock);
 503        val = mcp251x_read_reg(priv->spi, reg);
 504        mutex_unlock(&priv->mcp_lock);
 505
 506        return !!(val & mask);
 507}
 508
 509static int mcp251x_gpio_get_multiple(struct gpio_chip *chip,
 510                                     unsigned long *maskp, unsigned long *bitsp)
 511{
 512        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 513        unsigned long bits = 0;
 514        u8 val;
 515
 516        mutex_lock(&priv->mcp_lock);
 517        if (maskp[0] & MCP251X_GPIO_INPUT_MASK) {
 518                val = mcp251x_read_reg(priv->spi, TXRTSCTRL);
 519                val = FIELD_GET(TXRTSCTRL_RTS_MASK, val);
 520                bits |= FIELD_PREP(MCP251X_GPIO_INPUT_MASK, val);
 521        }
 522        if (maskp[0] & MCP251X_GPIO_OUTPUT_MASK) {
 523                val = mcp251x_read_reg(priv->spi, BFPCTRL);
 524                val = FIELD_GET(BFPCTRL_BFS_MASK, val);
 525                bits |= FIELD_PREP(MCP251X_GPIO_OUTPUT_MASK, val);
 526        }
 527        mutex_unlock(&priv->mcp_lock);
 528
 529        bitsp[0] = bits;
 530        return 0;
 531}
 532
 533static void mcp251x_gpio_set(struct gpio_chip *chip, unsigned int offset,
 534                             int value)
 535{
 536        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 537        u8 mask, val;
 538
 539        mask = BFPCTRL_BFS(offset - MCP251X_GPIO_RX0BF);
 540        val = value ? mask : 0;
 541
 542        mutex_lock(&priv->mcp_lock);
 543        mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);
 544        mutex_unlock(&priv->mcp_lock);
 545
 546        priv->reg_bfpctrl &= ~mask;
 547        priv->reg_bfpctrl |= val;
 548}
 549
 550static void
 551mcp251x_gpio_set_multiple(struct gpio_chip *chip,
 552                          unsigned long *maskp, unsigned long *bitsp)
 553{
 554        struct mcp251x_priv *priv = gpiochip_get_data(chip);
 555        u8 mask, val;
 556
 557        mask = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, maskp[0]);
 558        mask = FIELD_PREP(BFPCTRL_BFS_MASK, mask);
 559
 560        val = FIELD_GET(MCP251X_GPIO_OUTPUT_MASK, bitsp[0]);
 561        val = FIELD_PREP(BFPCTRL_BFS_MASK, val);
 562
 563        if (!mask)
 564                return;
 565
 566        mutex_lock(&priv->mcp_lock);
 567        mcp251x_write_bits(priv->spi, BFPCTRL, mask, val);
 568        mutex_unlock(&priv->mcp_lock);
 569
 570        priv->reg_bfpctrl &= ~mask;
 571        priv->reg_bfpctrl |= val;
 572}
 573
 574static void mcp251x_gpio_restore(struct spi_device *spi)
 575{
 576        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 577
 578        mcp251x_write_reg(spi, BFPCTRL, priv->reg_bfpctrl);
 579}
 580
 581static int mcp251x_gpio_setup(struct mcp251x_priv *priv)
 582{
 583        struct gpio_chip *gpio = &priv->gpio;
 584
 585        if (!device_property_present(&priv->spi->dev, "gpio-controller"))
 586                return 0;
 587
 588        /* gpiochip handles TX[0..2]RTS and RX[0..1]BF */
 589        gpio->label = priv->spi->modalias;
 590        gpio->parent = &priv->spi->dev;
 591        gpio->owner = THIS_MODULE;
 592        gpio->request = mcp251x_gpio_request;
 593        gpio->free = mcp251x_gpio_free;
 594        gpio->get_direction = mcp251x_gpio_get_direction;
 595        gpio->get = mcp251x_gpio_get;
 596        gpio->get_multiple = mcp251x_gpio_get_multiple;
 597        gpio->set = mcp251x_gpio_set;
 598        gpio->set_multiple = mcp251x_gpio_set_multiple;
 599        gpio->base = -1;
 600        gpio->ngpio = ARRAY_SIZE(mcp251x_gpio_names);
 601        gpio->names = mcp251x_gpio_names;
 602        gpio->can_sleep = true;
 603#ifdef CONFIG_OF_GPIO
 604        gpio->of_node = priv->spi->dev.of_node;
 605#endif
 606
 607        return devm_gpiochip_add_data(&priv->spi->dev, gpio, priv);
 608}
 609#else
 610static inline void mcp251x_gpio_restore(struct spi_device *spi)
 611{
 612}
 613
 614static inline int mcp251x_gpio_setup(struct mcp251x_priv *priv)
 615{
 616        return 0;
 617}
 618#endif
 619
 620static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
 621                                int len, int tx_buf_idx)
 622{
 623        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 624
 625        if (mcp251x_is_2510(spi)) {
 626                int i;
 627
 628                for (i = 1; i < TXBDAT_OFF + len; i++)
 629                        mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
 630                                          buf[i]);
 631        } else {
 632                memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
 633                mcp251x_spi_write(spi, TXBDAT_OFF + len);
 634        }
 635}
 636
 637static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
 638                          int tx_buf_idx)
 639{
 640        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 641        u32 sid, eid, exide, rtr;
 642        u8 buf[SPI_TRANSFER_BUF_LEN];
 643
 644        exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
 645        if (exide)
 646                sid = (frame->can_id & CAN_EFF_MASK) >> 18;
 647        else
 648                sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
 649        eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
 650        rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
 651
 652        buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
 653        buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
 654        buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
 655                (exide << SIDL_EXIDE_SHIFT) |
 656                ((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
 657        buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
 658        buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
 659        buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->len;
 660        memcpy(buf + TXBDAT_OFF, frame->data, frame->len);
 661        mcp251x_hw_tx_frame(spi, buf, frame->len, tx_buf_idx);
 662
 663        /* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
 664        priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
 665        mcp251x_spi_write(priv->spi, 1);
 666}
 667
 668static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
 669                                int buf_idx)
 670{
 671        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 672
 673        if (mcp251x_is_2510(spi)) {
 674                int i, len;
 675
 676                for (i = 1; i < RXBDAT_OFF; i++)
 677                        buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 678
 679                len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 680                for (; i < (RXBDAT_OFF + len); i++)
 681                        buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 682        } else {
 683                priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
 684                if (spi->controller->flags & SPI_CONTROLLER_HALF_DUPLEX) {
 685                        spi_write_then_read(spi, priv->spi_tx_buf, 1,
 686                                            priv->spi_rx_buf,
 687                                            SPI_TRANSFER_BUF_LEN);
 688                        memcpy(buf + 1, priv->spi_rx_buf,
 689                               SPI_TRANSFER_BUF_LEN - 1);
 690                } else {
 691                        mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
 692                        memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
 693                }
 694        }
 695}
 696
 697static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 698{
 699        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 700        struct sk_buff *skb;
 701        struct can_frame *frame;
 702        u8 buf[SPI_TRANSFER_BUF_LEN];
 703
 704        skb = alloc_can_skb(priv->net, &frame);
 705        if (!skb) {
 706                dev_err(&spi->dev, "cannot allocate RX skb\n");
 707                priv->net->stats.rx_dropped++;
 708                return;
 709        }
 710
 711        mcp251x_hw_rx_frame(spi, buf, buf_idx);
 712        if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
 713                /* Extended ID format */
 714                frame->can_id = CAN_EFF_FLAG;
 715                frame->can_id |=
 716                        /* Extended ID part */
 717                        SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
 718                        SET_BYTE(buf[RXBEID8_OFF], 1) |
 719                        SET_BYTE(buf[RXBEID0_OFF], 0) |
 720                        /* Standard ID part */
 721                        (((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 722                          (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
 723                /* Remote transmission request */
 724                if (buf[RXBDLC_OFF] & RXBDLC_RTR)
 725                        frame->can_id |= CAN_RTR_FLAG;
 726        } else {
 727                /* Standard ID format */
 728                frame->can_id =
 729                        (buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 730                        (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
 731                if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
 732                        frame->can_id |= CAN_RTR_FLAG;
 733        }
 734        /* Data length */
 735        frame->len = can_cc_dlc2len(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 736        memcpy(frame->data, buf + RXBDAT_OFF, frame->len);
 737
 738        priv->net->stats.rx_packets++;
 739        priv->net->stats.rx_bytes += frame->len;
 740
 741        can_led_event(priv->net, CAN_LED_EVENT_RX);
 742
 743        netif_rx_ni(skb);
 744}
 745
 746static void mcp251x_hw_sleep(struct spi_device *spi)
 747{
 748        mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
 749}
 750
 751/* May only be called when device is sleeping! */
 752static int mcp251x_hw_wake(struct spi_device *spi)
 753{
 754        u8 value;
 755        int ret;
 756
 757        /* Force wakeup interrupt to wake device, but don't execute IST */
 758        disable_irq(spi->irq);
 759        mcp251x_write_2regs(spi, CANINTE, CANINTE_WAKIE, CANINTF_WAKIF);
 760
 761        /* Wait for oscillator startup timer after wake up */
 762        mdelay(MCP251X_OST_DELAY_MS);
 763
 764        /* Put device into config mode */
 765        mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_CONF);
 766
 767        /* Wait for the device to enter config mode */
 768        ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF,
 769                                             MCP251X_OST_DELAY_MS * 1000,
 770                                             USEC_PER_SEC);
 771        if (ret) {
 772                dev_err(&spi->dev, "MCP251x didn't enter in config mode\n");
 773                return ret;
 774        }
 775
 776        /* Disable and clear pending interrupts */
 777        mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);
 778        enable_irq(spi->irq);
 779
 780        return 0;
 781}
 782
 783static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
 784                                           struct net_device *net)
 785{
 786        struct mcp251x_priv *priv = netdev_priv(net);
 787        struct spi_device *spi = priv->spi;
 788
 789        if (priv->tx_skb || priv->tx_len) {
 790                dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
 791                return NETDEV_TX_BUSY;
 792        }
 793
 794        if (can_dropped_invalid_skb(net, skb))
 795                return NETDEV_TX_OK;
 796
 797        netif_stop_queue(net);
 798        priv->tx_skb = skb;
 799        queue_work(priv->wq, &priv->tx_work);
 800
 801        return NETDEV_TX_OK;
 802}
 803
 804static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
 805{
 806        struct mcp251x_priv *priv = netdev_priv(net);
 807
 808        switch (mode) {
 809        case CAN_MODE_START:
 810                mcp251x_clean(net);
 811                /* We have to delay work since SPI I/O may sleep */
 812                priv->can.state = CAN_STATE_ERROR_ACTIVE;
 813                priv->restart_tx = 1;
 814                if (priv->can.restart_ms == 0)
 815                        priv->after_suspend = AFTER_SUSPEND_RESTART;
 816                queue_work(priv->wq, &priv->restart_work);
 817                break;
 818        default:
 819                return -EOPNOTSUPP;
 820        }
 821
 822        return 0;
 823}
 824
 825static int mcp251x_set_normal_mode(struct spi_device *spi)
 826{
 827        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 828        u8 value;
 829        int ret;
 830
 831        /* Enable interrupts */
 832        mcp251x_write_reg(spi, CANINTE,
 833                          CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
 834                          CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
 835
 836        if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 837                /* Put device into loopback mode */
 838                mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
 839        } else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 840                /* Put device into listen-only mode */
 841                mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
 842        } else {
 843                /* Put device into normal mode */
 844                mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
 845
 846                /* Wait for the device to enter normal mode */
 847                ret = mcp251x_read_stat_poll_timeout(spi, value, value == 0,
 848                                                     MCP251X_OST_DELAY_MS * 1000,
 849                                                     USEC_PER_SEC);
 850                if (ret) {
 851                        dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n");
 852                        return ret;
 853                }
 854        }
 855        priv->can.state = CAN_STATE_ERROR_ACTIVE;
 856        return 0;
 857}
 858
 859static int mcp251x_do_set_bittiming(struct net_device *net)
 860{
 861        struct mcp251x_priv *priv = netdev_priv(net);
 862        struct can_bittiming *bt = &priv->can.bittiming;
 863        struct spi_device *spi = priv->spi;
 864
 865        mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
 866                          (bt->brp - 1));
 867        mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
 868                          (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
 869                           CNF2_SAM : 0) |
 870                          ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
 871                          (bt->prop_seg - 1));
 872        mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
 873                           (bt->phase_seg2 - 1));
 874        dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
 875                mcp251x_read_reg(spi, CNF1),
 876                mcp251x_read_reg(spi, CNF2),
 877                mcp251x_read_reg(spi, CNF3));
 878
 879        return 0;
 880}
 881
 882static int mcp251x_setup(struct net_device *net, struct spi_device *spi)
 883{
 884        mcp251x_do_set_bittiming(net);
 885
 886        mcp251x_write_reg(spi, RXBCTRL(0),
 887                          RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
 888        mcp251x_write_reg(spi, RXBCTRL(1),
 889                          RXBCTRL_RXM0 | RXBCTRL_RXM1);
 890        return 0;
 891}
 892
 893static int mcp251x_hw_reset(struct spi_device *spi)
 894{
 895        struct mcp251x_priv *priv = spi_get_drvdata(spi);
 896        u8 value;
 897        int ret;
 898
 899        /* Wait for oscillator startup timer after power up */
 900        mdelay(MCP251X_OST_DELAY_MS);
 901
 902        priv->spi_tx_buf[0] = INSTRUCTION_RESET;
 903        ret = mcp251x_spi_write(spi, 1);
 904        if (ret)
 905                return ret;
 906
 907        /* Wait for oscillator startup timer after reset */
 908        mdelay(MCP251X_OST_DELAY_MS);
 909
 910        /* Wait for reset to finish */
 911        ret = mcp251x_read_stat_poll_timeout(spi, value, value == CANCTRL_REQOP_CONF,
 912                                             MCP251X_OST_DELAY_MS * 1000,
 913                                             USEC_PER_SEC);
 914        if (ret)
 915                dev_err(&spi->dev, "MCP251x didn't enter in conf mode after reset\n");
 916        return ret;
 917}
 918
 919static int mcp251x_hw_probe(struct spi_device *spi)
 920{
 921        u8 ctrl;
 922        int ret;
 923
 924        ret = mcp251x_hw_reset(spi);
 925        if (ret)
 926                return ret;
 927
 928        ctrl = mcp251x_read_reg(spi, CANCTRL);
 929
 930        dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
 931
 932        /* Check for power up default value */
 933        if ((ctrl & 0x17) != 0x07)
 934                return -ENODEV;
 935
 936        return 0;
 937}
 938
 939static int mcp251x_power_enable(struct regulator *reg, int enable)
 940{
 941        if (IS_ERR_OR_NULL(reg))
 942                return 0;
 943
 944        if (enable)
 945                return regulator_enable(reg);
 946        else
 947                return regulator_disable(reg);
 948}
 949
 950static int mcp251x_stop(struct net_device *net)
 951{
 952        struct mcp251x_priv *priv = netdev_priv(net);
 953        struct spi_device *spi = priv->spi;
 954
 955        close_candev(net);
 956
 957        priv->force_quit = 1;
 958        free_irq(spi->irq, priv);
 959
 960        mutex_lock(&priv->mcp_lock);
 961
 962        /* Disable and clear pending interrupts */
 963        mcp251x_write_2regs(spi, CANINTE, 0x00, 0x00);
 964
 965        mcp251x_write_reg(spi, TXBCTRL(0), 0);
 966        mcp251x_clean(net);
 967
 968        mcp251x_hw_sleep(spi);
 969
 970        mcp251x_power_enable(priv->transceiver, 0);
 971
 972        priv->can.state = CAN_STATE_STOPPED;
 973
 974        mutex_unlock(&priv->mcp_lock);
 975
 976        can_led_event(net, CAN_LED_EVENT_STOP);
 977
 978        return 0;
 979}
 980
 981static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
 982{
 983        struct sk_buff *skb;
 984        struct can_frame *frame;
 985
 986        skb = alloc_can_err_skb(net, &frame);
 987        if (skb) {
 988                frame->can_id |= can_id;
 989                frame->data[1] = data1;
 990                netif_rx_ni(skb);
 991        } else {
 992                netdev_err(net, "cannot allocate error skb\n");
 993        }
 994}
 995
 996static void mcp251x_tx_work_handler(struct work_struct *ws)
 997{
 998        struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
 999                                                 tx_work);
1000        struct spi_device *spi = priv->spi;
1001        struct net_device *net = priv->net;
1002        struct can_frame *frame;
1003
1004        mutex_lock(&priv->mcp_lock);
1005        if (priv->tx_skb) {
1006                if (priv->can.state == CAN_STATE_BUS_OFF) {
1007                        mcp251x_clean(net);
1008                } else {
1009                        frame = (struct can_frame *)priv->tx_skb->data;
1010
1011                        if (frame->len > CAN_FRAME_MAX_DATA_LEN)
1012                                frame->len = CAN_FRAME_MAX_DATA_LEN;
1013                        mcp251x_hw_tx(spi, frame, 0);
1014                        priv->tx_len = 1 + frame->len;
1015                        can_put_echo_skb(priv->tx_skb, net, 0, 0);
1016                        priv->tx_skb = NULL;
1017                }
1018        }
1019        mutex_unlock(&priv->mcp_lock);
1020}
1021
1022static void mcp251x_restart_work_handler(struct work_struct *ws)
1023{
1024        struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
1025                                                 restart_work);
1026        struct spi_device *spi = priv->spi;
1027        struct net_device *net = priv->net;
1028
1029        mutex_lock(&priv->mcp_lock);
1030        if (priv->after_suspend) {
1031                if (priv->after_suspend & AFTER_SUSPEND_POWER) {
1032                        mcp251x_hw_reset(spi);
1033                        mcp251x_setup(net, spi);
1034                        mcp251x_gpio_restore(spi);
1035                } else {
1036                        mcp251x_hw_wake(spi);
1037                }
1038                priv->force_quit = 0;
1039                if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
1040                        mcp251x_set_normal_mode(spi);
1041                } else if (priv->after_suspend & AFTER_SUSPEND_UP) {
1042                        netif_device_attach(net);
1043                        mcp251x_clean(net);
1044                        mcp251x_set_normal_mode(spi);
1045                        netif_wake_queue(net);
1046                } else {
1047                        mcp251x_hw_sleep(spi);
1048                }
1049                priv->after_suspend = 0;
1050        }
1051
1052        if (priv->restart_tx) {
1053                priv->restart_tx = 0;
1054                mcp251x_write_reg(spi, TXBCTRL(0), 0);
1055                mcp251x_clean(net);
1056                netif_wake_queue(net);
1057                mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
1058        }
1059        mutex_unlock(&priv->mcp_lock);
1060}
1061
1062static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
1063{
1064        struct mcp251x_priv *priv = dev_id;
1065        struct spi_device *spi = priv->spi;
1066        struct net_device *net = priv->net;
1067
1068        mutex_lock(&priv->mcp_lock);
1069        while (!priv->force_quit) {
1070                enum can_state new_state;
1071                u8 intf, eflag;
1072                u8 clear_intf = 0;
1073                int can_id = 0, data1 = 0;
1074
1075                mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
1076
1077                /* mask out flags we don't care about */
1078                intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
1079
1080                /* receive buffer 0 */
1081                if (intf & CANINTF_RX0IF) {
1082                        mcp251x_hw_rx(spi, 0);
1083                        /* Free one buffer ASAP
1084                         * (The MCP2515/25625 does this automatically.)
1085                         */
1086                        if (mcp251x_is_2510(spi))
1087                                mcp251x_write_bits(spi, CANINTF,
1088                                                   CANINTF_RX0IF, 0x00);
1089                }
1090
1091                /* receive buffer 1 */
1092                if (intf & CANINTF_RX1IF) {
1093                        mcp251x_hw_rx(spi, 1);
1094                        /* The MCP2515/25625 does this automatically. */
1095                        if (mcp251x_is_2510(spi))
1096                                clear_intf |= CANINTF_RX1IF;
1097                }
1098
1099                /* any error or tx interrupt we need to clear? */
1100                if (intf & (CANINTF_ERR | CANINTF_TX))
1101                        clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
1102                if (clear_intf)
1103                        mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
1104
1105                if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR))
1106                        mcp251x_write_bits(spi, EFLG, eflag, 0x00);
1107
1108                /* Update can state */
1109                if (eflag & EFLG_TXBO) {
1110                        new_state = CAN_STATE_BUS_OFF;
1111                        can_id |= CAN_ERR_BUSOFF;
1112                } else if (eflag & EFLG_TXEP) {
1113                        new_state = CAN_STATE_ERROR_PASSIVE;
1114                        can_id |= CAN_ERR_CRTL;
1115                        data1 |= CAN_ERR_CRTL_TX_PASSIVE;
1116                } else if (eflag & EFLG_RXEP) {
1117                        new_state = CAN_STATE_ERROR_PASSIVE;
1118                        can_id |= CAN_ERR_CRTL;
1119                        data1 |= CAN_ERR_CRTL_RX_PASSIVE;
1120                } else if (eflag & EFLG_TXWAR) {
1121                        new_state = CAN_STATE_ERROR_WARNING;
1122                        can_id |= CAN_ERR_CRTL;
1123                        data1 |= CAN_ERR_CRTL_TX_WARNING;
1124                } else if (eflag & EFLG_RXWAR) {
1125                        new_state = CAN_STATE_ERROR_WARNING;
1126                        can_id |= CAN_ERR_CRTL;
1127                        data1 |= CAN_ERR_CRTL_RX_WARNING;
1128                } else {
1129                        new_state = CAN_STATE_ERROR_ACTIVE;
1130                }
1131
1132                /* Update can state statistics */
1133                switch (priv->can.state) {
1134                case CAN_STATE_ERROR_ACTIVE:
1135                        if (new_state >= CAN_STATE_ERROR_WARNING &&
1136                            new_state <= CAN_STATE_BUS_OFF)
1137                                priv->can.can_stats.error_warning++;
1138                        fallthrough;
1139                case CAN_STATE_ERROR_WARNING:
1140                        if (new_state >= CAN_STATE_ERROR_PASSIVE &&
1141                            new_state <= CAN_STATE_BUS_OFF)
1142                                priv->can.can_stats.error_passive++;
1143                        break;
1144                default:
1145                        break;
1146                }
1147                priv->can.state = new_state;
1148
1149                if (intf & CANINTF_ERRIF) {
1150                        /* Handle overflow counters */
1151                        if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
1152                                if (eflag & EFLG_RX0OVR) {
1153                                        net->stats.rx_over_errors++;
1154                                        net->stats.rx_errors++;
1155                                }
1156                                if (eflag & EFLG_RX1OVR) {
1157                                        net->stats.rx_over_errors++;
1158                                        net->stats.rx_errors++;
1159                                }
1160                                can_id |= CAN_ERR_CRTL;
1161                                data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
1162                        }
1163                        mcp251x_error_skb(net, can_id, data1);
1164                }
1165
1166                if (priv->can.state == CAN_STATE_BUS_OFF) {
1167                        if (priv->can.restart_ms == 0) {
1168                                priv->force_quit = 1;
1169                                priv->can.can_stats.bus_off++;
1170                                can_bus_off(net);
1171                                mcp251x_hw_sleep(spi);
1172                                break;
1173                        }
1174                }
1175
1176                if (intf == 0)
1177                        break;
1178
1179                if (intf & CANINTF_TX) {
1180                        net->stats.tx_packets++;
1181                        net->stats.tx_bytes += priv->tx_len - 1;
1182                        can_led_event(net, CAN_LED_EVENT_TX);
1183                        if (priv->tx_len) {
1184                                can_get_echo_skb(net, 0, NULL);
1185                                priv->tx_len = 0;
1186                        }
1187                        netif_wake_queue(net);
1188                }
1189        }
1190        mutex_unlock(&priv->mcp_lock);
1191        return IRQ_HANDLED;
1192}
1193
1194static int mcp251x_open(struct net_device *net)
1195{
1196        struct mcp251x_priv *priv = netdev_priv(net);
1197        struct spi_device *spi = priv->spi;
1198        unsigned long flags = 0;
1199        int ret;
1200
1201        ret = open_candev(net);
1202        if (ret) {
1203                dev_err(&spi->dev, "unable to set initial baudrate!\n");
1204                return ret;
1205        }
1206
1207        mutex_lock(&priv->mcp_lock);
1208        mcp251x_power_enable(priv->transceiver, 1);
1209
1210        priv->force_quit = 0;
1211        priv->tx_skb = NULL;
1212        priv->tx_len = 0;
1213
1214        if (!dev_fwnode(&spi->dev))
1215                flags = IRQF_TRIGGER_FALLING;
1216
1217        ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
1218                                   flags | IRQF_ONESHOT, dev_name(&spi->dev),
1219                                   priv);
1220        if (ret) {
1221                dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
1222                goto out_close;
1223        }
1224
1225        ret = mcp251x_hw_wake(spi);
1226        if (ret)
1227                goto out_free_irq;
1228        ret = mcp251x_setup(net, spi);
1229        if (ret)
1230                goto out_free_irq;
1231        ret = mcp251x_set_normal_mode(spi);
1232        if (ret)
1233                goto out_free_irq;
1234
1235        can_led_event(net, CAN_LED_EVENT_OPEN);
1236
1237        netif_wake_queue(net);
1238        mutex_unlock(&priv->mcp_lock);
1239
1240        return 0;
1241
1242out_free_irq:
1243        free_irq(spi->irq, priv);
1244        mcp251x_hw_sleep(spi);
1245out_close:
1246        mcp251x_power_enable(priv->transceiver, 0);
1247        close_candev(net);
1248        mutex_unlock(&priv->mcp_lock);
1249        return ret;
1250}
1251
1252static const struct net_device_ops mcp251x_netdev_ops = {
1253        .ndo_open = mcp251x_open,
1254        .ndo_stop = mcp251x_stop,
1255        .ndo_start_xmit = mcp251x_hard_start_xmit,
1256        .ndo_change_mtu = can_change_mtu,
1257};
1258
1259static const struct of_device_id mcp251x_of_match[] = {
1260        {
1261                .compatible     = "microchip,mcp2510",
1262                .data           = (void *)CAN_MCP251X_MCP2510,
1263        },
1264        {
1265                .compatible     = "microchip,mcp2515",
1266                .data           = (void *)CAN_MCP251X_MCP2515,
1267        },
1268        {
1269                .compatible     = "microchip,mcp25625",
1270                .data           = (void *)CAN_MCP251X_MCP25625,
1271        },
1272        { }
1273};
1274MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1275
1276static const struct spi_device_id mcp251x_id_table[] = {
1277        {
1278                .name           = "mcp2510",
1279                .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2510,
1280        },
1281        {
1282                .name           = "mcp2515",
1283                .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP2515,
1284        },
1285        {
1286                .name           = "mcp25625",
1287                .driver_data    = (kernel_ulong_t)CAN_MCP251X_MCP25625,
1288        },
1289        { }
1290};
1291MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1292
1293static int mcp251x_can_probe(struct spi_device *spi)
1294{
1295        const void *match = device_get_match_data(&spi->dev);
1296        struct net_device *net;
1297        struct mcp251x_priv *priv;
1298        struct clk *clk;
1299        u32 freq;
1300        int ret;
1301
1302        clk = devm_clk_get_optional(&spi->dev, NULL);
1303        if (IS_ERR(clk))
1304                return PTR_ERR(clk);
1305
1306        freq = clk_get_rate(clk);
1307        if (freq == 0)
1308                device_property_read_u32(&spi->dev, "clock-frequency", &freq);
1309
1310        /* Sanity check */
1311        if (freq < 1000000 || freq > 25000000)
1312                return -ERANGE;
1313
1314        /* Allocate can/net device */
1315        net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1316        if (!net)
1317                return -ENOMEM;
1318
1319        ret = clk_prepare_enable(clk);
1320        if (ret)
1321                goto out_free;
1322
1323        net->netdev_ops = &mcp251x_netdev_ops;
1324        net->flags |= IFF_ECHO;
1325
1326        priv = netdev_priv(net);
1327        priv->can.bittiming_const = &mcp251x_bittiming_const;
1328        priv->can.do_set_mode = mcp251x_do_set_mode;
1329        priv->can.clock.freq = freq / 2;
1330        priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1331                CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1332        if (match)
1333                priv->model = (enum mcp251x_model)(uintptr_t)match;
1334        else
1335                priv->model = spi_get_device_id(spi)->driver_data;
1336        priv->net = net;
1337        priv->clk = clk;
1338
1339        spi_set_drvdata(spi, priv);
1340
1341        /* Configure the SPI bus */
1342        spi->bits_per_word = 8;
1343        if (mcp251x_is_2510(spi))
1344                spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1345        else
1346                spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1347        ret = spi_setup(spi);
1348        if (ret)
1349                goto out_clk;
1350
1351        priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
1352        priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
1353        if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1354            (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1355                ret = -EPROBE_DEFER;
1356                goto out_clk;
1357        }
1358
1359        ret = mcp251x_power_enable(priv->power, 1);
1360        if (ret)
1361                goto out_clk;
1362
1363        priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
1364                                   0);
1365        if (!priv->wq) {
1366                ret = -ENOMEM;
1367                goto out_clk;
1368        }
1369        INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
1370        INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
1371
1372        priv->spi = spi;
1373        mutex_init(&priv->mcp_lock);
1374
1375        priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1376                                        GFP_KERNEL);
1377        if (!priv->spi_tx_buf) {
1378                ret = -ENOMEM;
1379                goto error_probe;
1380        }
1381
1382        priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1383                                        GFP_KERNEL);
1384        if (!priv->spi_rx_buf) {
1385                ret = -ENOMEM;
1386                goto error_probe;
1387        }
1388
1389        SET_NETDEV_DEV(net, &spi->dev);
1390
1391        /* Here is OK to not lock the MCP, no one knows about it yet */
1392        ret = mcp251x_hw_probe(spi);
1393        if (ret) {
1394                if (ret == -ENODEV)
1395                        dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n",
1396                                priv->model);
1397                goto error_probe;
1398        }
1399
1400        mcp251x_hw_sleep(spi);
1401
1402        ret = register_candev(net);
1403        if (ret)
1404                goto error_probe;
1405
1406        devm_can_led_init(net);
1407
1408        ret = mcp251x_gpio_setup(priv);
1409        if (ret)
1410                goto error_probe;
1411
1412        netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
1413        return 0;
1414
1415error_probe:
1416        destroy_workqueue(priv->wq);
1417        priv->wq = NULL;
1418        mcp251x_power_enable(priv->power, 0);
1419
1420out_clk:
1421        clk_disable_unprepare(clk);
1422
1423out_free:
1424        free_candev(net);
1425
1426        dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
1427        return ret;
1428}
1429
1430static int mcp251x_can_remove(struct spi_device *spi)
1431{
1432        struct mcp251x_priv *priv = spi_get_drvdata(spi);
1433        struct net_device *net = priv->net;
1434
1435        unregister_candev(net);
1436
1437        mcp251x_power_enable(priv->power, 0);
1438
1439        destroy_workqueue(priv->wq);
1440        priv->wq = NULL;
1441
1442        clk_disable_unprepare(priv->clk);
1443
1444        free_candev(net);
1445
1446        return 0;
1447}
1448
1449static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1450{
1451        struct spi_device *spi = to_spi_device(dev);
1452        struct mcp251x_priv *priv = spi_get_drvdata(spi);
1453        struct net_device *net = priv->net;
1454
1455        priv->force_quit = 1;
1456        disable_irq(spi->irq);
1457        /* Note: at this point neither IST nor workqueues are running.
1458         * open/stop cannot be called anyway so locking is not needed
1459         */
1460        if (netif_running(net)) {
1461                netif_device_detach(net);
1462
1463                mcp251x_hw_sleep(spi);
1464                mcp251x_power_enable(priv->transceiver, 0);
1465                priv->after_suspend = AFTER_SUSPEND_UP;
1466        } else {
1467                priv->after_suspend = AFTER_SUSPEND_DOWN;
1468        }
1469
1470        mcp251x_power_enable(priv->power, 0);
1471        priv->after_suspend |= AFTER_SUSPEND_POWER;
1472
1473        return 0;
1474}
1475
1476static int __maybe_unused mcp251x_can_resume(struct device *dev)
1477{
1478        struct spi_device *spi = to_spi_device(dev);
1479        struct mcp251x_priv *priv = spi_get_drvdata(spi);
1480
1481        if (priv->after_suspend & AFTER_SUSPEND_POWER)
1482                mcp251x_power_enable(priv->power, 1);
1483        if (priv->after_suspend & AFTER_SUSPEND_UP)
1484                mcp251x_power_enable(priv->transceiver, 1);
1485
1486        if (priv->after_suspend & (AFTER_SUSPEND_POWER | AFTER_SUSPEND_UP))
1487                queue_work(priv->wq, &priv->restart_work);
1488        else
1489                priv->after_suspend = 0;
1490
1491        priv->force_quit = 0;
1492        enable_irq(spi->irq);
1493        return 0;
1494}
1495
1496static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1497        mcp251x_can_resume);
1498
1499static struct spi_driver mcp251x_can_driver = {
1500        .driver = {
1501                .name = DEVICE_NAME,
1502                .of_match_table = mcp251x_of_match,
1503                .pm = &mcp251x_can_pm_ops,
1504        },
1505        .id_table = mcp251x_id_table,
1506        .probe = mcp251x_can_probe,
1507        .remove = mcp251x_can_remove,
1508};
1509module_spi_driver(mcp251x_can_driver);
1510
1511MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1512              "Christian Pellegrin <chripell@evolware.org>");
1513MODULE_DESCRIPTION("Microchip 251x/25625 CAN driver");
1514MODULE_LICENSE("GPL v2");
1515