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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 Marc Kleine-Budde, Pengutronix
   7 *
   8 * Based on code originally by Andrey Volkov <avolkov@varma-el.com>
   9 *
  10 * LICENCE:
  11 * This program is free software; you can redistribute it and/or
  12 * modify it under the terms of the GNU General Public License as
  13 * published by the Free Software Foundation version 2.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 */
  21
  22#include <linux/netdevice.h>
  23#include <linux/can.h>
  24#include <linux/can/dev.h>
  25#include <linux/can/error.h>
  26#include <linux/can/led.h>
  27#include <linux/clk.h>
  28#include <linux/delay.h>
  29#include <linux/interrupt.h>
  30#include <linux/io.h>
  31#include <linux/module.h>
  32#include <linux/of.h>
  33#include <linux/of_device.h>
  34#include <linux/platform_device.h>
  35#include <linux/regulator/consumer.h>
  36
  37#define DRV_NAME			"flexcan"
  38
  39/* 8 for RX fifo and 2 error handling */
  40#define FLEXCAN_NAPI_WEIGHT		(8 + 2)
  41
  42/* FLEXCAN module configuration register (CANMCR) bits */
  43#define FLEXCAN_MCR_MDIS		BIT(31)
  44#define FLEXCAN_MCR_FRZ			BIT(30)
  45#define FLEXCAN_MCR_FEN			BIT(29)
  46#define FLEXCAN_MCR_HALT		BIT(28)
  47#define FLEXCAN_MCR_NOT_RDY		BIT(27)
  48#define FLEXCAN_MCR_WAK_MSK		BIT(26)
  49#define FLEXCAN_MCR_SOFTRST		BIT(25)
  50#define FLEXCAN_MCR_FRZ_ACK		BIT(24)
  51#define FLEXCAN_MCR_SUPV		BIT(23)
  52#define FLEXCAN_MCR_SLF_WAK		BIT(22)
  53#define FLEXCAN_MCR_WRN_EN		BIT(21)
  54#define FLEXCAN_MCR_LPM_ACK		BIT(20)
  55#define FLEXCAN_MCR_WAK_SRC		BIT(19)
  56#define FLEXCAN_MCR_DOZE		BIT(18)
  57#define FLEXCAN_MCR_SRX_DIS		BIT(17)
  58#define FLEXCAN_MCR_BCC			BIT(16)
  59#define FLEXCAN_MCR_LPRIO_EN		BIT(13)
  60#define FLEXCAN_MCR_AEN			BIT(12)
  61#define FLEXCAN_MCR_MAXMB(x)		((x) & 0x7f)
  62#define FLEXCAN_MCR_IDAM_A		(0x0 << 8)
  63#define FLEXCAN_MCR_IDAM_B		(0x1 << 8)
  64#define FLEXCAN_MCR_IDAM_C		(0x2 << 8)
  65#define FLEXCAN_MCR_IDAM_D		(0x3 << 8)
  66
  67/* FLEXCAN control register (CANCTRL) bits */
  68#define FLEXCAN_CTRL_PRESDIV(x)		(((x) & 0xff) << 24)
  69#define FLEXCAN_CTRL_RJW(x)		(((x) & 0x03) << 22)
  70#define FLEXCAN_CTRL_PSEG1(x)		(((x) & 0x07) << 19)
  71#define FLEXCAN_CTRL_PSEG2(x)		(((x) & 0x07) << 16)
  72#define FLEXCAN_CTRL_BOFF_MSK		BIT(15)
  73#define FLEXCAN_CTRL_ERR_MSK		BIT(14)
  74#define FLEXCAN_CTRL_CLK_SRC		BIT(13)
  75#define FLEXCAN_CTRL_LPB		BIT(12)
  76#define FLEXCAN_CTRL_TWRN_MSK		BIT(11)
  77#define FLEXCAN_CTRL_RWRN_MSK		BIT(10)
  78#define FLEXCAN_CTRL_SMP		BIT(7)
  79#define FLEXCAN_CTRL_BOFF_REC		BIT(6)
  80#define FLEXCAN_CTRL_TSYN		BIT(5)
  81#define FLEXCAN_CTRL_LBUF		BIT(4)
  82#define FLEXCAN_CTRL_LOM		BIT(3)
  83#define FLEXCAN_CTRL_PROPSEG(x)		((x) & 0x07)
  84#define FLEXCAN_CTRL_ERR_BUS		(FLEXCAN_CTRL_ERR_MSK)
  85#define FLEXCAN_CTRL_ERR_STATE \
  86	(FLEXCAN_CTRL_TWRN_MSK | FLEXCAN_CTRL_RWRN_MSK | \
  87	 FLEXCAN_CTRL_BOFF_MSK)
  88#define FLEXCAN_CTRL_ERR_ALL \
  89	(FLEXCAN_CTRL_ERR_BUS | FLEXCAN_CTRL_ERR_STATE)
  90
  91/* FLEXCAN control register 2 (CTRL2) bits */
  92#define FLEXCAN_CTRL2_ECRWRE		BIT(29)
  93#define FLEXCAN_CTRL2_WRMFRZ		BIT(28)
  94#define FLEXCAN_CTRL2_RFFN(x)		(((x) & 0x0f) << 24)
  95#define FLEXCAN_CTRL2_TASD(x)		(((x) & 0x1f) << 19)
  96#define FLEXCAN_CTRL2_MRP		BIT(18)
  97#define FLEXCAN_CTRL2_RRS		BIT(17)
  98#define FLEXCAN_CTRL2_EACEN		BIT(16)
  99
 100/* FLEXCAN memory error control register (MECR) bits */
 101#define FLEXCAN_MECR_ECRWRDIS		BIT(31)
 102#define FLEXCAN_MECR_HANCEI_MSK		BIT(19)
 103#define FLEXCAN_MECR_FANCEI_MSK		BIT(18)
 104#define FLEXCAN_MECR_CEI_MSK		BIT(16)
 105#define FLEXCAN_MECR_HAERRIE		BIT(15)
 106#define FLEXCAN_MECR_FAERRIE		BIT(14)
 107#define FLEXCAN_MECR_EXTERRIE		BIT(13)
 108#define FLEXCAN_MECR_RERRDIS		BIT(9)
 109#define FLEXCAN_MECR_ECCDIS		BIT(8)
 110#define FLEXCAN_MECR_NCEFAFRZ		BIT(7)
 111
 112/* FLEXCAN error and status register (ESR) bits */
 113#define FLEXCAN_ESR_TWRN_INT		BIT(17)
 114#define FLEXCAN_ESR_RWRN_INT		BIT(16)
 115#define FLEXCAN_ESR_BIT1_ERR		BIT(15)
 116#define FLEXCAN_ESR_BIT0_ERR		BIT(14)
 117#define FLEXCAN_ESR_ACK_ERR		BIT(13)
 118#define FLEXCAN_ESR_CRC_ERR		BIT(12)
 119#define FLEXCAN_ESR_FRM_ERR		BIT(11)
 120#define FLEXCAN_ESR_STF_ERR		BIT(10)
 121#define FLEXCAN_ESR_TX_WRN		BIT(9)
 122#define FLEXCAN_ESR_RX_WRN		BIT(8)
 123#define FLEXCAN_ESR_IDLE		BIT(7)
 124#define FLEXCAN_ESR_TXRX		BIT(6)
 125#define FLEXCAN_EST_FLT_CONF_SHIFT	(4)
 126#define FLEXCAN_ESR_FLT_CONF_MASK	(0x3 << FLEXCAN_EST_FLT_CONF_SHIFT)
 127#define FLEXCAN_ESR_FLT_CONF_ACTIVE	(0x0 << FLEXCAN_EST_FLT_CONF_SHIFT)
 128#define FLEXCAN_ESR_FLT_CONF_PASSIVE	(0x1 << FLEXCAN_EST_FLT_CONF_SHIFT)
 129#define FLEXCAN_ESR_BOFF_INT		BIT(2)
 130#define FLEXCAN_ESR_ERR_INT		BIT(1)
 131#define FLEXCAN_ESR_WAK_INT		BIT(0)
 132#define FLEXCAN_ESR_ERR_BUS \
 133	(FLEXCAN_ESR_BIT1_ERR | FLEXCAN_ESR_BIT0_ERR | \
 134	 FLEXCAN_ESR_ACK_ERR | FLEXCAN_ESR_CRC_ERR | \
 135	 FLEXCAN_ESR_FRM_ERR | FLEXCAN_ESR_STF_ERR)
 136#define FLEXCAN_ESR_ERR_STATE \
 137	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | FLEXCAN_ESR_BOFF_INT)
 138#define FLEXCAN_ESR_ERR_ALL \
 139	(FLEXCAN_ESR_ERR_BUS | FLEXCAN_ESR_ERR_STATE)
 140#define FLEXCAN_ESR_ALL_INT \
 141	(FLEXCAN_ESR_TWRN_INT | FLEXCAN_ESR_RWRN_INT | \
 142	 FLEXCAN_ESR_BOFF_INT | FLEXCAN_ESR_ERR_INT)
 143
 144/* FLEXCAN interrupt flag register (IFLAG) bits */
 145/* Errata ERR005829 step7: Reserve first valid MB */
 146#define FLEXCAN_TX_BUF_RESERVED		8
 147#define FLEXCAN_TX_BUF_ID		9
 148#define FLEXCAN_IFLAG_BUF(x)		BIT(x)
 149#define FLEXCAN_IFLAG_RX_FIFO_OVERFLOW	BIT(7)
 150#define FLEXCAN_IFLAG_RX_FIFO_WARN	BIT(6)
 151#define FLEXCAN_IFLAG_RX_FIFO_AVAILABLE	BIT(5)
 152#define FLEXCAN_IFLAG_DEFAULT \
 153	(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW | FLEXCAN_IFLAG_RX_FIFO_AVAILABLE | \
 154	 FLEXCAN_IFLAG_BUF(FLEXCAN_TX_BUF_ID))
 155
 156/* FLEXCAN message buffers */
 157#define FLEXCAN_MB_CODE_RX_INACTIVE	(0x0 << 24)
 158#define FLEXCAN_MB_CODE_RX_EMPTY	(0x4 << 24)
 159#define FLEXCAN_MB_CODE_RX_FULL		(0x2 << 24)
 160#define FLEXCAN_MB_CODE_RX_OVERRUN	(0x6 << 24)
 161#define FLEXCAN_MB_CODE_RX_RANSWER	(0xa << 24)
 162
 163#define FLEXCAN_MB_CODE_TX_INACTIVE	(0x8 << 24)
 164#define FLEXCAN_MB_CODE_TX_ABORT	(0x9 << 24)
 165#define FLEXCAN_MB_CODE_TX_DATA		(0xc << 24)
 166#define FLEXCAN_MB_CODE_TX_TANSWER	(0xe << 24)
 167
 168#define FLEXCAN_MB_CNT_SRR		BIT(22)
 169#define FLEXCAN_MB_CNT_IDE		BIT(21)
 170#define FLEXCAN_MB_CNT_RTR		BIT(20)
 171#define FLEXCAN_MB_CNT_LENGTH(x)	(((x) & 0xf) << 16)
 172#define FLEXCAN_MB_CNT_TIMESTAMP(x)	((x) & 0xffff)
 173
 174#define FLEXCAN_TIMEOUT_US		(50)
 175
 176/* FLEXCAN hardware feature flags
 177 *
 178 * Below is some version info we got:
 179 *    SOC   Version   IP-Version  Glitch- [TR]WRN_INT Memory err RTR re-
 180 *                                Filter? connected?  detection  ception in MB
 181 *   MX25  FlexCAN2  03.00.00.00     no        no         no        no
 182 *   MX28  FlexCAN2  03.00.04.00    yes       yes         no        no
 183 *   MX35  FlexCAN2  03.00.00.00     no        no         no        no
 184 *   MX53  FlexCAN2  03.00.00.00    yes        no         no        no
 185 *   MX6s  FlexCAN3  10.00.12.00    yes       yes         no       yes
 186 *   VF610 FlexCAN3  ?               no       yes        yes       yes?
 187 *
 188 * Some SOCs do not have the RX_WARN & TX_WARN interrupt line connected.
 189 */
 190#define FLEXCAN_QUIRK_BROKEN_ERR_STATE	BIT(1) /* [TR]WRN_INT not connected */
 191#define FLEXCAN_QUIRK_DISABLE_RXFG	BIT(2) /* Disable RX FIFO Global mask */
 192#define FLEXCAN_QUIRK_DISABLE_MECR	BIT(3) /* Disble Memory error detection */
 193
 194/* Structure of the message buffer */
 195struct flexcan_mb {
 196	u32 can_ctrl;
 197	u32 can_id;
 198	u32 data[2];
 199};
 200
 201/* Structure of the hardware registers */
 202struct flexcan_regs {
 203	u32 mcr;		/* 0x00 */
 204	u32 ctrl;		/* 0x04 */
 205	u32 timer;		/* 0x08 */
 206	u32 _reserved1;		/* 0x0c */
 207	u32 rxgmask;		/* 0x10 */
 208	u32 rx14mask;		/* 0x14 */
 209	u32 rx15mask;		/* 0x18 */
 210	u32 ecr;		/* 0x1c */
 211	u32 esr;		/* 0x20 */
 212	u32 imask2;		/* 0x24 */
 213	u32 imask1;		/* 0x28 */
 214	u32 iflag2;		/* 0x2c */
 215	u32 iflag1;		/* 0x30 */
 216	u32 ctrl2;		/* 0x34 */
 217	u32 esr2;		/* 0x38 */
 218	u32 imeur;		/* 0x3c */
 219	u32 lrfr;		/* 0x40 */
 220	u32 crcr;		/* 0x44 */
 221	u32 rxfgmask;		/* 0x48 */
 222	u32 rxfir;		/* 0x4c */
 223	u32 _reserved3[12];	/* 0x50 */
 224	struct flexcan_mb mb[64];	/* 0x80 */
 225	/* FIFO-mode:
 226	 *			MB
 227	 * 0x080...0x08f	0	RX message buffer
 228	 * 0x090...0x0df	1-5	reserverd
 229	 * 0x0e0...0x0ff	6-7	8 entry ID table
 230	 *				(mx25, mx28, mx35, mx53)
 231	 * 0x0e0...0x2df	6-7..37	8..128 entry ID table
 232	 *				size conf'ed via ctrl2::RFFN
 233	 *				(mx6, vf610)
 234	 */
 235	u32 _reserved4[408];
 236	u32 mecr;		/* 0xae0 */
 237	u32 erriar;		/* 0xae4 */
 238	u32 erridpr;		/* 0xae8 */
 239	u32 errippr;		/* 0xaec */
 240	u32 rerrar;		/* 0xaf0 */
 241	u32 rerrdr;		/* 0xaf4 */
 242	u32 rerrsynr;		/* 0xaf8 */
 243	u32 errsr;		/* 0xafc */
 244};
 245
 246struct flexcan_devtype_data {
 247	u32 quirks;		/* quirks needed for different IP cores */
 248};
 249
 250struct flexcan_priv {
 251	struct can_priv can;
 252	struct napi_struct napi;
 253
 254	struct flexcan_regs __iomem *regs;
 255	u32 reg_esr;
 256	u32 reg_ctrl_default;
 257
 258	struct clk *clk_ipg;
 259	struct clk *clk_per;
 260	struct flexcan_platform_data *pdata;
 261	const struct flexcan_devtype_data *devtype_data;
 262	struct regulator *reg_xceiver;
 263};
 264
 265static struct flexcan_devtype_data fsl_p1010_devtype_data = {
 266	.quirks = FLEXCAN_QUIRK_BROKEN_ERR_STATE,
 267};
 268
 269static struct flexcan_devtype_data fsl_imx28_devtype_data;
 270
 271static struct flexcan_devtype_data fsl_imx6q_devtype_data = {
 272	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG,
 273};
 274
 275static struct flexcan_devtype_data fsl_vf610_devtype_data = {
 276	.quirks = FLEXCAN_QUIRK_DISABLE_RXFG | FLEXCAN_QUIRK_DISABLE_MECR,
 277};
 278
 279static const struct can_bittiming_const flexcan_bittiming_const = {
 280	.name = DRV_NAME,
 281	.tseg1_min = 4,
 282	.tseg1_max = 16,
 283	.tseg2_min = 2,
 284	.tseg2_max = 8,
 285	.sjw_max = 4,
 286	.brp_min = 1,
 287	.brp_max = 256,
 288	.brp_inc = 1,
 289};
 290
 291/* Abstract off the read/write for arm versus ppc. This
 292 * assumes that PPC uses big-endian registers and everything
 293 * else uses little-endian registers, independent of CPU
 294 * endianness.
 295 */
 296#if defined(CONFIG_PPC)
 297static inline u32 flexcan_read(void __iomem *addr)
 298{
 299	return in_be32(addr);
 300}
 301
 302static inline void flexcan_write(u32 val, void __iomem *addr)
 303{
 304	out_be32(addr, val);
 305}
 306#else
 307static inline u32 flexcan_read(void __iomem *addr)
 308{
 309	return readl(addr);
 310}
 311
 312static inline void flexcan_write(u32 val, void __iomem *addr)
 313{
 314	writel(val, addr);
 315}
 316#endif
 317
 318static inline int flexcan_transceiver_enable(const struct flexcan_priv *priv)
 319{
 320	if (!priv->reg_xceiver)
 321		return 0;
 322
 323	return regulator_enable(priv->reg_xceiver);
 324}
 325
 326static inline int flexcan_transceiver_disable(const struct flexcan_priv *priv)
 327{
 328	if (!priv->reg_xceiver)
 329		return 0;
 330
 331	return regulator_disable(priv->reg_xceiver);
 332}
 333
 334static inline int flexcan_has_and_handle_berr(const struct flexcan_priv *priv,
 335					      u32 reg_esr)
 336{
 337	return (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING) &&
 338		(reg_esr & FLEXCAN_ESR_ERR_BUS);
 339}
 340
 341static int flexcan_chip_enable(struct flexcan_priv *priv)
 342{
 343	struct flexcan_regs __iomem *regs = priv->regs;
 344	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 345	u32 reg;
 346
 347	reg = flexcan_read(&regs->mcr);
 348	reg &= ~FLEXCAN_MCR_MDIS;
 349	flexcan_write(reg, &regs->mcr);
 350
 351	while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 352		udelay(10);
 353
 354	if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK)
 355		return -ETIMEDOUT;
 356
 357	return 0;
 358}
 359
 360static int flexcan_chip_disable(struct flexcan_priv *priv)
 361{
 362	struct flexcan_regs __iomem *regs = priv->regs;
 363	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 364	u32 reg;
 365
 366	reg = flexcan_read(&regs->mcr);
 367	reg |= FLEXCAN_MCR_MDIS;
 368	flexcan_write(reg, &regs->mcr);
 369
 370	while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 371		udelay(10);
 372
 373	if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_LPM_ACK))
 374		return -ETIMEDOUT;
 375
 376	return 0;
 377}
 378
 379static int flexcan_chip_freeze(struct flexcan_priv *priv)
 380{
 381	struct flexcan_regs __iomem *regs = priv->regs;
 382	unsigned int timeout = 1000 * 1000 * 10 / priv->can.bittiming.bitrate;
 383	u32 reg;
 384
 385	reg = flexcan_read(&regs->mcr);
 386	reg |= FLEXCAN_MCR_HALT;
 387	flexcan_write(reg, &regs->mcr);
 388
 389	while (timeout-- && !(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 390		udelay(100);
 391
 392	if (!(flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 393		return -ETIMEDOUT;
 394
 395	return 0;
 396}
 397
 398static int flexcan_chip_unfreeze(struct flexcan_priv *priv)
 399{
 400	struct flexcan_regs __iomem *regs = priv->regs;
 401	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 402	u32 reg;
 403
 404	reg = flexcan_read(&regs->mcr);
 405	reg &= ~FLEXCAN_MCR_HALT;
 406	flexcan_write(reg, &regs->mcr);
 407
 408	while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK))
 409		udelay(10);
 410
 411	if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_FRZ_ACK)
 412		return -ETIMEDOUT;
 413
 414	return 0;
 415}
 416
 417static int flexcan_chip_softreset(struct flexcan_priv *priv)
 418{
 419	struct flexcan_regs __iomem *regs = priv->regs;
 420	unsigned int timeout = FLEXCAN_TIMEOUT_US / 10;
 421
 422	flexcan_write(FLEXCAN_MCR_SOFTRST, &regs->mcr);
 423	while (timeout-- && (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST))
 424		udelay(10);
 425
 426	if (flexcan_read(&regs->mcr) & FLEXCAN_MCR_SOFTRST)
 427		return -ETIMEDOUT;
 428
 429	return 0;
 430}
 431
 432static int __flexcan_get_berr_counter(const struct net_device *dev,
 433				      struct can_berr_counter *bec)
 434{
 435	const struct flexcan_priv *priv = netdev_priv(dev);
 436	struct flexcan_regs __iomem *regs = priv->regs;
 437	u32 reg = flexcan_read(&regs->ecr);
 438
 439	bec->txerr = (reg >> 0) & 0xff;
 440	bec->rxerr = (reg >> 8) & 0xff;
 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	int err;
 450
 451	err = clk_prepare_enable(priv->clk_ipg);
 452	if (err)
 453		return err;
 454
 455	err = clk_prepare_enable(priv->clk_per);
 456	if (err)
 457		goto out_disable_ipg;
 458
 459	err = __flexcan_get_berr_counter(dev, bec);
 460
 461	clk_disable_unprepare(priv->clk_per);
 462 out_disable_ipg:
 463	clk_disable_unprepare(priv->clk_ipg);
 464
 465	return err;
 466}
 467
 468static int flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 469{
 470	const struct flexcan_priv *priv = netdev_priv(dev);
 471	struct flexcan_regs __iomem *regs = priv->regs;
 472	struct can_frame *cf = (struct can_frame *)skb->data;
 473	u32 can_id;
 474	u32 data;
 475	u32 ctrl = FLEXCAN_MB_CODE_TX_DATA | (cf->can_dlc << 16);
 476
 477	if (can_dropped_invalid_skb(dev, skb))
 478		return NETDEV_TX_OK;
 479
 480	netif_stop_queue(dev);
 481
 482	if (cf->can_id & CAN_EFF_FLAG) {
 483		can_id = cf->can_id & CAN_EFF_MASK;
 484		ctrl |= FLEXCAN_MB_CNT_IDE | FLEXCAN_MB_CNT_SRR;
 485	} else {
 486		can_id = (cf->can_id & CAN_SFF_MASK) << 18;
 487	}
 488
 489	if (cf->can_id & CAN_RTR_FLAG)
 490		ctrl |= FLEXCAN_MB_CNT_RTR;
 491
 492	if (cf->can_dlc > 0) {
 493		data = be32_to_cpup((__be32 *)&cf->data[0]);
 494		flexcan_write(data, &regs->mb[FLEXCAN_TX_BUF_ID].data[0]);
 495	}
 496	if (cf->can_dlc > 3) {
 497		data = be32_to_cpup((__be32 *)&cf->data[4]);
 498		flexcan_write(data, &regs->mb[FLEXCAN_TX_BUF_ID].data[1]);
 499	}
 500
 501	can_put_echo_skb(skb, dev, 0);
 502
 503	flexcan_write(can_id, &regs->mb[FLEXCAN_TX_BUF_ID].can_id);
 504	flexcan_write(ctrl, &regs->mb[FLEXCAN_TX_BUF_ID].can_ctrl);
 505
 506	/* Errata ERR005829 step8:
 507	 * Write twice INACTIVE(0x8) code to first MB.
 508	 */
 509	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 510		      &regs->mb[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
 511	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 512		      &regs->mb[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
 513
 514	return NETDEV_TX_OK;
 515}
 516
 517static void do_bus_err(struct net_device *dev,
 518		       struct can_frame *cf, u32 reg_esr)
 519{
 520	struct flexcan_priv *priv = netdev_priv(dev);
 521	int rx_errors = 0, tx_errors = 0;
 522
 523	cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 524
 525	if (reg_esr & FLEXCAN_ESR_BIT1_ERR) {
 526		netdev_dbg(dev, "BIT1_ERR irq\n");
 527		cf->data[2] |= CAN_ERR_PROT_BIT1;
 528		tx_errors = 1;
 529	}
 530	if (reg_esr & FLEXCAN_ESR_BIT0_ERR) {
 531		netdev_dbg(dev, "BIT0_ERR irq\n");
 532		cf->data[2] |= CAN_ERR_PROT_BIT0;
 533		tx_errors = 1;
 534	}
 535	if (reg_esr & FLEXCAN_ESR_ACK_ERR) {
 536		netdev_dbg(dev, "ACK_ERR irq\n");
 537		cf->can_id |= CAN_ERR_ACK;
 538		cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 539		tx_errors = 1;
 540	}
 541	if (reg_esr & FLEXCAN_ESR_CRC_ERR) {
 542		netdev_dbg(dev, "CRC_ERR irq\n");
 543		cf->data[2] |= CAN_ERR_PROT_BIT;
 544		cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 545		rx_errors = 1;
 546	}
 547	if (reg_esr & FLEXCAN_ESR_FRM_ERR) {
 548		netdev_dbg(dev, "FRM_ERR irq\n");
 549		cf->data[2] |= CAN_ERR_PROT_FORM;
 550		rx_errors = 1;
 551	}
 552	if (reg_esr & FLEXCAN_ESR_STF_ERR) {
 553		netdev_dbg(dev, "STF_ERR irq\n");
 554		cf->data[2] |= CAN_ERR_PROT_STUFF;
 555		rx_errors = 1;
 556	}
 557
 558	priv->can.can_stats.bus_error++;
 559	if (rx_errors)
 560		dev->stats.rx_errors++;
 561	if (tx_errors)
 562		dev->stats.tx_errors++;
 563}
 564
 565static int flexcan_poll_bus_err(struct net_device *dev, u32 reg_esr)
 566{
 567	struct sk_buff *skb;
 568	struct can_frame *cf;
 569
 570	skb = alloc_can_err_skb(dev, &cf);
 571	if (unlikely(!skb))
 572		return 0;
 573
 574	do_bus_err(dev, cf, reg_esr);
 575
 576	dev->stats.rx_packets++;
 577	dev->stats.rx_bytes += cf->can_dlc;
 578	netif_receive_skb(skb);
 579
 580	return 1;
 581}
 582
 583static int flexcan_poll_state(struct net_device *dev, u32 reg_esr)
 584{
 585	struct flexcan_priv *priv = netdev_priv(dev);
 586	struct sk_buff *skb;
 587	struct can_frame *cf;
 588	enum can_state new_state = 0, rx_state = 0, tx_state = 0;
 589	int flt;
 590	struct can_berr_counter bec;
 591
 592	flt = reg_esr & FLEXCAN_ESR_FLT_CONF_MASK;
 593	if (likely(flt == FLEXCAN_ESR_FLT_CONF_ACTIVE)) {
 594		tx_state = unlikely(reg_esr & FLEXCAN_ESR_TX_WRN) ?
 595			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
 596		rx_state = unlikely(reg_esr & FLEXCAN_ESR_RX_WRN) ?
 597			CAN_STATE_ERROR_WARNING : CAN_STATE_ERROR_ACTIVE;
 598		new_state = max(tx_state, rx_state);
 599	} else {
 600		__flexcan_get_berr_counter(dev, &bec);
 601		new_state = flt == FLEXCAN_ESR_FLT_CONF_PASSIVE ?
 602			CAN_STATE_ERROR_PASSIVE : CAN_STATE_BUS_OFF;
 603		rx_state = bec.rxerr >= bec.txerr ? new_state : 0;
 604		tx_state = bec.rxerr <= bec.txerr ? new_state : 0;
 605	}
 606
 607	/* state hasn't changed */
 608	if (likely(new_state == priv->can.state))
 609		return 0;
 610
 611	skb = alloc_can_err_skb(dev, &cf);
 612	if (unlikely(!skb))
 613		return 0;
 614
 615	can_change_state(dev, cf, tx_state, rx_state);
 616
 617	if (unlikely(new_state == CAN_STATE_BUS_OFF))
 618		can_bus_off(dev);
 619
 620	dev->stats.rx_packets++;
 621	dev->stats.rx_bytes += cf->can_dlc;
 622	netif_receive_skb(skb);
 623
 624	return 1;
 625}
 626
 627static void flexcan_read_fifo(const struct net_device *dev,
 628			      struct can_frame *cf)
 629{
 630	const struct flexcan_priv *priv = netdev_priv(dev);
 631	struct flexcan_regs __iomem *regs = priv->regs;
 632	struct flexcan_mb __iomem *mb = &regs->mb[0];
 633	u32 reg_ctrl, reg_id;
 634
 635	reg_ctrl = flexcan_read(&mb->can_ctrl);
 636	reg_id = flexcan_read(&mb->can_id);
 637	if (reg_ctrl & FLEXCAN_MB_CNT_IDE)
 638		cf->can_id = ((reg_id >> 0) & CAN_EFF_MASK) | CAN_EFF_FLAG;
 639	else
 640		cf->can_id = (reg_id >> 18) & CAN_SFF_MASK;
 641
 642	if (reg_ctrl & FLEXCAN_MB_CNT_RTR)
 643		cf->can_id |= CAN_RTR_FLAG;
 644	cf->can_dlc = get_can_dlc((reg_ctrl >> 16) & 0xf);
 645
 646	*(__be32 *)(cf->data + 0) = cpu_to_be32(flexcan_read(&mb->data[0]));
 647	*(__be32 *)(cf->data + 4) = cpu_to_be32(flexcan_read(&mb->data[1]));
 648
 649	/* mark as read */
 650	flexcan_write(FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->iflag1);
 651	flexcan_read(&regs->timer);
 652}
 653
 654static int flexcan_read_frame(struct net_device *dev)
 655{
 656	struct net_device_stats *stats = &dev->stats;
 657	struct can_frame *cf;
 658	struct sk_buff *skb;
 659
 660	skb = alloc_can_skb(dev, &cf);
 661	if (unlikely(!skb)) {
 662		stats->rx_dropped++;
 663		return 0;
 664	}
 665
 666	flexcan_read_fifo(dev, cf);
 667
 668	stats->rx_packets++;
 669	stats->rx_bytes += cf->can_dlc;
 670	netif_receive_skb(skb);
 671
 672	can_led_event(dev, CAN_LED_EVENT_RX);
 673
 674	return 1;
 675}
 676
 677static int flexcan_poll(struct napi_struct *napi, int quota)
 678{
 679	struct net_device *dev = napi->dev;
 680	const struct flexcan_priv *priv = netdev_priv(dev);
 681	struct flexcan_regs __iomem *regs = priv->regs;
 682	u32 reg_iflag1, reg_esr;
 683	int work_done = 0;
 684
 685	/* The error bits are cleared on read,
 686	 * use saved value from irq handler.
 687	 */
 688	reg_esr = flexcan_read(&regs->esr) | priv->reg_esr;
 689
 690	/* handle state changes */
 691	work_done += flexcan_poll_state(dev, reg_esr);
 692
 693	/* handle RX-FIFO */
 694	reg_iflag1 = flexcan_read(&regs->iflag1);
 695	while (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE &&
 696	       work_done < quota) {
 697		work_done += flexcan_read_frame(dev);
 698		reg_iflag1 = flexcan_read(&regs->iflag1);
 699	}
 700
 701	/* report bus errors */
 702	if (flexcan_has_and_handle_berr(priv, reg_esr) && work_done < quota)
 703		work_done += flexcan_poll_bus_err(dev, reg_esr);
 704
 705	if (work_done < quota) {
 706		napi_complete(napi);
 707		/* enable IRQs */
 708		flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
 709		flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
 710	}
 711
 712	return work_done;
 713}
 714
 715static irqreturn_t flexcan_irq(int irq, void *dev_id)
 716{
 717	struct net_device *dev = dev_id;
 718	struct net_device_stats *stats = &dev->stats;
 719	struct flexcan_priv *priv = netdev_priv(dev);
 720	struct flexcan_regs __iomem *regs = priv->regs;
 721	u32 reg_iflag1, reg_esr;
 722
 723	reg_iflag1 = flexcan_read(&regs->iflag1);
 724	reg_esr = flexcan_read(&regs->esr);
 725
 726	/* ACK all bus error and state change IRQ sources */
 727	if (reg_esr & FLEXCAN_ESR_ALL_INT)
 728		flexcan_write(reg_esr & FLEXCAN_ESR_ALL_INT, &regs->esr);
 729
 730	/* schedule NAPI in case of:
 731	 * - rx IRQ
 732	 * - state change IRQ
 733	 * - bus error IRQ and bus error reporting is activated
 734	 */
 735	if ((reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_AVAILABLE) ||
 736	    (reg_esr & FLEXCAN_ESR_ERR_STATE) ||
 737	    flexcan_has_and_handle_berr(priv, reg_esr)) {
 738		/* The error bits are cleared on read,
 739		 * save them for later use.
 740		 */
 741		priv->reg_esr = reg_esr & FLEXCAN_ESR_ERR_BUS;
 742		flexcan_write(FLEXCAN_IFLAG_DEFAULT &
 743			      ~FLEXCAN_IFLAG_RX_FIFO_AVAILABLE, &regs->imask1);
 744		flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
 745			      &regs->ctrl);
 746		napi_schedule(&priv->napi);
 747	}
 748
 749	/* FIFO overflow */
 750	if (reg_iflag1 & FLEXCAN_IFLAG_RX_FIFO_OVERFLOW) {
 751		flexcan_write(FLEXCAN_IFLAG_RX_FIFO_OVERFLOW, &regs->iflag1);
 752		dev->stats.rx_over_errors++;
 753		dev->stats.rx_errors++;
 754	}
 755
 756	/* transmission complete interrupt */
 757	if (reg_iflag1 & (1 << FLEXCAN_TX_BUF_ID)) {
 758		stats->tx_bytes += can_get_echo_skb(dev, 0);
 759		stats->tx_packets++;
 760		can_led_event(dev, CAN_LED_EVENT_TX);
 761
 762		/* after sending a RTR frame MB is in RX mode */
 763		flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 764			      &regs->mb[FLEXCAN_TX_BUF_ID].can_ctrl);
 765		flexcan_write((1 << FLEXCAN_TX_BUF_ID), &regs->iflag1);
 766		netif_wake_queue(dev);
 767	}
 768
 769	return IRQ_HANDLED;
 770}
 771
 772static void flexcan_set_bittiming(struct net_device *dev)
 773{
 774	const struct flexcan_priv *priv = netdev_priv(dev);
 775	const struct can_bittiming *bt = &priv->can.bittiming;
 776	struct flexcan_regs __iomem *regs = priv->regs;
 777	u32 reg;
 778
 779	reg = flexcan_read(&regs->ctrl);
 780	reg &= ~(FLEXCAN_CTRL_PRESDIV(0xff) |
 781		 FLEXCAN_CTRL_RJW(0x3) |
 782		 FLEXCAN_CTRL_PSEG1(0x7) |
 783		 FLEXCAN_CTRL_PSEG2(0x7) |
 784		 FLEXCAN_CTRL_PROPSEG(0x7) |
 785		 FLEXCAN_CTRL_LPB |
 786		 FLEXCAN_CTRL_SMP |
 787		 FLEXCAN_CTRL_LOM);
 788
 789	reg |= FLEXCAN_CTRL_PRESDIV(bt->brp - 1) |
 790		FLEXCAN_CTRL_PSEG1(bt->phase_seg1 - 1) |
 791		FLEXCAN_CTRL_PSEG2(bt->phase_seg2 - 1) |
 792		FLEXCAN_CTRL_RJW(bt->sjw - 1) |
 793		FLEXCAN_CTRL_PROPSEG(bt->prop_seg - 1);
 794
 795	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
 796		reg |= FLEXCAN_CTRL_LPB;
 797	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
 798		reg |= FLEXCAN_CTRL_LOM;
 799	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
 800		reg |= FLEXCAN_CTRL_SMP;
 801
 802	netdev_dbg(dev, "writing ctrl=0x%08x\n", reg);
 803	flexcan_write(reg, &regs->ctrl);
 804
 805	/* print chip status */
 806	netdev_dbg(dev, "%s: mcr=0x%08x ctrl=0x%08x\n", __func__,
 807		   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 808}
 809
 810/* flexcan_chip_start
 811 *
 812 * this functions is entered with clocks enabled
 813 *
 814 */
 815static int flexcan_chip_start(struct net_device *dev)
 816{
 817	struct flexcan_priv *priv = netdev_priv(dev);
 818	struct flexcan_regs __iomem *regs = priv->regs;
 819	u32 reg_mcr, reg_ctrl, reg_ctrl2, reg_mecr;
 820	int err, i;
 821
 822	/* enable module */
 823	err = flexcan_chip_enable(priv);
 824	if (err)
 825		return err;
 826
 827	/* soft reset */
 828	err = flexcan_chip_softreset(priv);
 829	if (err)
 830		goto out_chip_disable;
 831
 832	flexcan_set_bittiming(dev);
 833
 834	/* MCR
 835	 *
 836	 * enable freeze
 837	 * enable fifo
 838	 * halt now
 839	 * only supervisor access
 840	 * enable warning int
 841	 * disable local echo
 842	 * choose format C
 843	 * set max mailbox number
 844	 */
 845	reg_mcr = flexcan_read(&regs->mcr);
 846	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);
 847	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_FEN | FLEXCAN_MCR_HALT |
 848		FLEXCAN_MCR_SUPV | FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS |
 849		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(FLEXCAN_TX_BUF_ID);
 850	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);
 851	flexcan_write(reg_mcr, &regs->mcr);
 852
 853	/* CTRL
 854	 *
 855	 * disable timer sync feature
 856	 *
 857	 * disable auto busoff recovery
 858	 * transmit lowest buffer first
 859	 *
 860	 * enable tx and rx warning interrupt
 861	 * enable bus off interrupt
 862	 * (== FLEXCAN_CTRL_ERR_STATE)
 863	 */
 864	reg_ctrl = flexcan_read(&regs->ctrl);
 865	reg_ctrl &= ~FLEXCAN_CTRL_TSYN;
 866	reg_ctrl |= FLEXCAN_CTRL_BOFF_REC | FLEXCAN_CTRL_LBUF |
 867		FLEXCAN_CTRL_ERR_STATE;
 868
 869	/* enable the "error interrupt" (FLEXCAN_CTRL_ERR_MSK),
 870	 * on most Flexcan cores, too. Otherwise we don't get
 871	 * any error warning or passive interrupts.
 872	 */
 873	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_BROKEN_ERR_STATE ||
 874	    priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
 875		reg_ctrl |= FLEXCAN_CTRL_ERR_MSK;
 876	else
 877		reg_ctrl &= ~FLEXCAN_CTRL_ERR_MSK;
 878
 879	/* save for later use */
 880	priv->reg_ctrl_default = reg_ctrl;
 881	/* leave interrupts disabled for now */
 882	reg_ctrl &= ~FLEXCAN_CTRL_ERR_ALL;
 883	netdev_dbg(dev, "%s: writing ctrl=0x%08x", __func__, reg_ctrl);
 884	flexcan_write(reg_ctrl, &regs->ctrl);
 885
 886	/* clear and invalidate all mailboxes first */
 887	for (i = FLEXCAN_TX_BUF_ID; i < ARRAY_SIZE(regs->mb); i++) {
 888		flexcan_write(FLEXCAN_MB_CODE_RX_INACTIVE,
 889			      &regs->mb[i].can_ctrl);
 890	}
 891
 892	/* Errata ERR005829: mark first TX mailbox as INACTIVE */
 893	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 894		      &regs->mb[FLEXCAN_TX_BUF_RESERVED].can_ctrl);
 895
 896	/* mark TX mailbox as INACTIVE */
 897	flexcan_write(FLEXCAN_MB_CODE_TX_INACTIVE,
 898		      &regs->mb[FLEXCAN_TX_BUF_ID].can_ctrl);
 899
 900	/* acceptance mask/acceptance code (accept everything) */
 901	flexcan_write(0x0, &regs->rxgmask);
 902	flexcan_write(0x0, &regs->rx14mask);
 903	flexcan_write(0x0, &regs->rx15mask);
 904
 905	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_RXFG)
 906		flexcan_write(0x0, &regs->rxfgmask);
 907
 908	/* On Vybrid, disable memory error detection interrupts
 909	 * and freeze mode.
 910	 * This also works around errata e5295 which generates
 911	 * false positive memory errors and put the device in
 912	 * freeze mode.
 913	 */
 914	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_DISABLE_MECR) {
 915		/* Follow the protocol as described in "Detection
 916		 * and Correction of Memory Errors" to write to
 917		 * MECR register
 918		 */
 919		reg_ctrl2 = flexcan_read(&regs->ctrl2);
 920		reg_ctrl2 |= FLEXCAN_CTRL2_ECRWRE;
 921		flexcan_write(reg_ctrl2, &regs->ctrl2);
 922
 923		reg_mecr = flexcan_read(&regs->mecr);
 924		reg_mecr &= ~FLEXCAN_MECR_ECRWRDIS;
 925		flexcan_write(reg_mecr, &regs->mecr);
 926		reg_mecr &= ~(FLEXCAN_MECR_NCEFAFRZ | FLEXCAN_MECR_HANCEI_MSK |
 927			      FLEXCAN_MECR_FANCEI_MSK);
 928		flexcan_write(reg_mecr, &regs->mecr);
 929	}
 930
 931	err = flexcan_transceiver_enable(priv);
 932	if (err)
 933		goto out_chip_disable;
 934
 935	/* synchronize with the can bus */
 936	err = flexcan_chip_unfreeze(priv);
 937	if (err)
 938		goto out_transceiver_disable;
 939
 940	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 941
 942	/* enable interrupts atomically */
 943	disable_irq(dev->irq);
 944	flexcan_write(priv->reg_ctrl_default, &regs->ctrl);
 945	flexcan_write(FLEXCAN_IFLAG_DEFAULT, &regs->imask1);
 946	enable_irq(dev->irq);
 947
 948	/* print chip status */
 949	netdev_dbg(dev, "%s: reading mcr=0x%08x ctrl=0x%08x\n", __func__,
 950		   flexcan_read(&regs->mcr), flexcan_read(&regs->ctrl));
 951
 952	return 0;
 953
 954 out_transceiver_disable:
 955	flexcan_transceiver_disable(priv);
 956 out_chip_disable:
 957	flexcan_chip_disable(priv);
 958	return err;
 959}
 960
 961/* flexcan_chip_stop
 962 *
 963 * this functions is entered with clocks enabled
 964 */
 965static void flexcan_chip_stop(struct net_device *dev)
 966{
 967	struct flexcan_priv *priv = netdev_priv(dev);
 968	struct flexcan_regs __iomem *regs = priv->regs;
 969
 970	/* freeze + disable module */
 971	flexcan_chip_freeze(priv);
 972	flexcan_chip_disable(priv);
 973
 974	/* Disable all interrupts */
 975	flexcan_write(0, &regs->imask1);
 976	flexcan_write(priv->reg_ctrl_default & ~FLEXCAN_CTRL_ERR_ALL,
 977		      &regs->ctrl);
 978
 979	flexcan_transceiver_disable(priv);
 980	priv->can.state = CAN_STATE_STOPPED;
 981}
 982
 983static int flexcan_open(struct net_device *dev)
 984{
 985	struct flexcan_priv *priv = netdev_priv(dev);
 986	int err;
 987
 988	err = clk_prepare_enable(priv->clk_ipg);
 989	if (err)
 990		return err;
 991
 992	err = clk_prepare_enable(priv->clk_per);
 993	if (err)
 994		goto out_disable_ipg;
 995
 996	err = open_candev(dev);
 997	if (err)
 998		goto out_disable_per;
 999
1000	err = request_irq(dev->irq, flexcan_irq, IRQF_SHARED, dev->name, dev);
1001	if (err)
1002		goto out_close;
1003
1004	/* start chip and queuing */
1005	err = flexcan_chip_start(dev);
1006	if (err)
1007		goto out_free_irq;
1008
1009	can_led_event(dev, CAN_LED_EVENT_OPEN);
1010
1011	napi_enable(&priv->napi);
1012	netif_start_queue(dev);
1013
1014	return 0;
1015
1016 out_free_irq:
1017	free_irq(dev->irq, dev);
1018 out_close:
1019	close_candev(dev);
1020 out_disable_per:
1021	clk_disable_unprepare(priv->clk_per);
1022 out_disable_ipg:
1023	clk_disable_unprepare(priv->clk_ipg);
1024
1025	return err;
1026}
1027
1028static int flexcan_close(struct net_device *dev)
1029{
1030	struct flexcan_priv *priv = netdev_priv(dev);
1031
1032	netif_stop_queue(dev);
1033	napi_disable(&priv->napi);
1034	flexcan_chip_stop(dev);
1035
1036	free_irq(dev->irq, dev);
1037	clk_disable_unprepare(priv->clk_per);
1038	clk_disable_unprepare(priv->clk_ipg);
1039
1040	close_candev(dev);
1041
1042	can_led_event(dev, CAN_LED_EVENT_STOP);
1043
1044	return 0;
1045}
1046
1047static int flexcan_set_mode(struct net_device *dev, enum can_mode mode)
1048{
1049	int err;
1050
1051	switch (mode) {
1052	case CAN_MODE_START:
1053		err = flexcan_chip_start(dev);
1054		if (err)
1055			return err;
1056
1057		netif_wake_queue(dev);
1058		break;
1059
1060	default:
1061		return -EOPNOTSUPP;
1062	}
1063
1064	return 0;
1065}
1066
1067static const struct net_device_ops flexcan_netdev_ops = {
1068	.ndo_open	= flexcan_open,
1069	.ndo_stop	= flexcan_close,
1070	.ndo_start_xmit	= flexcan_start_xmit,
1071	.ndo_change_mtu = can_change_mtu,
1072};
1073
1074static int register_flexcandev(struct net_device *dev)
1075{
1076	struct flexcan_priv *priv = netdev_priv(dev);
1077	struct flexcan_regs __iomem *regs = priv->regs;
1078	u32 reg, err;
1079
1080	err = clk_prepare_enable(priv->clk_ipg);
1081	if (err)
1082		return err;
1083
1084	err = clk_prepare_enable(priv->clk_per);
1085	if (err)
1086		goto out_disable_ipg;
1087
1088	/* select "bus clock", chip must be disabled */
1089	err = flexcan_chip_disable(priv);
1090	if (err)
1091		goto out_disable_per;
1092	reg = flexcan_read(&regs->ctrl);
1093	reg |= FLEXCAN_CTRL_CLK_SRC;
1094	flexcan_write(reg, &regs->ctrl);
1095
1096	err = flexcan_chip_enable(priv);
1097	if (err)
1098		goto out_chip_disable;
1099
1100	/* set freeze, halt and activate FIFO, restrict register access */
1101	reg = flexcan_read(&regs->mcr);
1102	reg |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT |
1103		FLEXCAN_MCR_FEN | FLEXCAN_MCR_SUPV;
1104	flexcan_write(reg, &regs->mcr);
1105
1106	/* Currently we only support newer versions of this core
1107	 * featuring a RX FIFO. Older cores found on some Coldfire
1108	 * derivates are not yet supported.
1109	 */
1110	reg = flexcan_read(&regs->mcr);
1111	if (!(reg & FLEXCAN_MCR_FEN)) {
1112		netdev_err(dev, "Could not enable RX FIFO, unsupported core\n");
1113		err = -ENODEV;
1114		goto out_chip_disable;
1115	}
1116
1117	err = register_candev(dev);
1118
1119	/* disable core and turn off clocks */
1120 out_chip_disable:
1121	flexcan_chip_disable(priv);
1122 out_disable_per:
1123	clk_disable_unprepare(priv->clk_per);
1124 out_disable_ipg:
1125	clk_disable_unprepare(priv->clk_ipg);
1126
1127	return err;
1128}
1129
1130static void unregister_flexcandev(struct net_device *dev)
1131{
1132	unregister_candev(dev);
1133}
1134
1135static const struct of_device_id flexcan_of_match[] = {
1136	{ .compatible = "fsl,imx6q-flexcan", .data = &fsl_imx6q_devtype_data, },
1137	{ .compatible = "fsl,imx28-flexcan", .data = &fsl_imx28_devtype_data, },
1138	{ .compatible = "fsl,p1010-flexcan", .data = &fsl_p1010_devtype_data, },
1139	{ .compatible = "fsl,vf610-flexcan", .data = &fsl_vf610_devtype_data, },
1140	{ /* sentinel */ },
1141};
1142MODULE_DEVICE_TABLE(of, flexcan_of_match);
1143
1144static const struct platform_device_id flexcan_id_table[] = {
1145	{ .name = "flexcan", .driver_data = (kernel_ulong_t)&fsl_p1010_devtype_data, },
1146	{ /* sentinel */ },
1147};
1148MODULE_DEVICE_TABLE(platform, flexcan_id_table);
1149
1150static int flexcan_probe(struct platform_device *pdev)
1151{
1152	const struct of_device_id *of_id;
1153	const struct flexcan_devtype_data *devtype_data;
1154	struct net_device *dev;
1155	struct flexcan_priv *priv;
1156	struct regulator *reg_xceiver;
1157	struct resource *mem;
1158	struct clk *clk_ipg = NULL, *clk_per = NULL;
1159	struct flexcan_regs __iomem *regs;
1160	int err, irq;
1161	u32 clock_freq = 0;
1162
1163	reg_xceiver = devm_regulator_get(&pdev->dev, "xceiver");
1164	if (PTR_ERR(reg_xceiver) == -EPROBE_DEFER)
1165		return -EPROBE_DEFER;
1166	else if (IS_ERR(reg_xceiver))
1167		reg_xceiver = NULL;
1168
1169	if (pdev->dev.of_node)
1170		of_property_read_u32(pdev->dev.of_node,
1171				     "clock-frequency", &clock_freq);
1172
1173	if (!clock_freq) {
1174		clk_ipg = devm_clk_get(&pdev->dev, "ipg");
1175		if (IS_ERR(clk_ipg)) {
1176			dev_err(&pdev->dev, "no ipg clock defined\n");
1177			return PTR_ERR(clk_ipg);
1178		}
1179
1180		clk_per = devm_clk_get(&pdev->dev, "per");
1181		if (IS_ERR(clk_per)) {
1182			dev_err(&pdev->dev, "no per clock defined\n");
1183			return PTR_ERR(clk_per);
1184		}
1185		clock_freq = clk_get_rate(clk_per);
1186	}
1187
1188	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1189	irq = platform_get_irq(pdev, 0);
1190	if (irq <= 0)
1191		return -ENODEV;
1192
1193	regs = devm_ioremap_resource(&pdev->dev, mem);
1194	if (IS_ERR(regs))
1195		return PTR_ERR(regs);
1196
1197	of_id = of_match_device(flexcan_of_match, &pdev->dev);
1198	if (of_id) {
1199		devtype_data = of_id->data;
1200	} else if (platform_get_device_id(pdev)->driver_data) {
1201		devtype_data = (struct flexcan_devtype_data *)
1202			platform_get_device_id(pdev)->driver_data;
1203	} else {
1204		return -ENODEV;
1205	}
1206
1207	dev = alloc_candev(sizeof(struct flexcan_priv), 1);
1208	if (!dev)
1209		return -ENOMEM;
1210
1211	dev->netdev_ops = &flexcan_netdev_ops;
1212	dev->irq = irq;
1213	dev->flags |= IFF_ECHO;
1214
1215	priv = netdev_priv(dev);
1216	priv->can.clock.freq = clock_freq;
1217	priv->can.bittiming_const = &flexcan_bittiming_const;
1218	priv->can.do_set_mode = flexcan_set_mode;
1219	priv->can.do_get_berr_counter = flexcan_get_berr_counter;
1220	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1221		CAN_CTRLMODE_LISTENONLY	| CAN_CTRLMODE_3_SAMPLES |
1222		CAN_CTRLMODE_BERR_REPORTING;
1223	priv->regs = regs;
1224	priv->clk_ipg = clk_ipg;
1225	priv->clk_per = clk_per;
1226	priv->pdata = dev_get_platdata(&pdev->dev);
1227	priv->devtype_data = devtype_data;
1228	priv->reg_xceiver = reg_xceiver;
1229
1230	netif_napi_add(dev, &priv->napi, flexcan_poll, FLEXCAN_NAPI_WEIGHT);
1231
1232	platform_set_drvdata(pdev, dev);
1233	SET_NETDEV_DEV(dev, &pdev->dev);
1234
1235	err = register_flexcandev(dev);
1236	if (err) {
1237		dev_err(&pdev->dev, "registering netdev failed\n");
1238		goto failed_register;
1239	}
1240
1241	devm_can_led_init(dev);
1242
1243	dev_info(&pdev->dev, "device registered (reg_base=%p, irq=%d)\n",
1244		 priv->regs, dev->irq);
1245
1246	return 0;
1247
1248 failed_register:
1249	free_candev(dev);
1250	return err;
1251}
1252
1253static int flexcan_remove(struct platform_device *pdev)
1254{
1255	struct net_device *dev = platform_get_drvdata(pdev);
1256	struct flexcan_priv *priv = netdev_priv(dev);
1257
1258	unregister_flexcandev(dev);
1259	netif_napi_del(&priv->napi);
1260	free_candev(dev);
1261
1262	return 0;
1263}
1264
1265static int __maybe_unused flexcan_suspend(struct device *device)
1266{
1267	struct net_device *dev = dev_get_drvdata(device);
1268	struct flexcan_priv *priv = netdev_priv(dev);
1269	int err;
1270
1271	err = flexcan_chip_disable(priv);
1272	if (err)
1273		return err;
1274
1275	if (netif_running(dev)) {
1276		netif_stop_queue(dev);
1277		netif_device_detach(dev);
1278	}
1279	priv->can.state = CAN_STATE_SLEEPING;
1280
1281	return 0;
1282}
1283
1284static int __maybe_unused flexcan_resume(struct device *device)
1285{
1286	struct net_device *dev = dev_get_drvdata(device);
1287	struct flexcan_priv *priv = netdev_priv(dev);
1288
1289	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1290	if (netif_running(dev)) {
1291		netif_device_attach(dev);
1292		netif_start_queue(dev);
1293	}
1294	return flexcan_chip_enable(priv);
1295}
1296
1297static SIMPLE_DEV_PM_OPS(flexcan_pm_ops, flexcan_suspend, flexcan_resume);
1298
1299static struct platform_driver flexcan_driver = {
1300	.driver = {
1301		.name = DRV_NAME,
1302		.pm = &flexcan_pm_ops,
1303		.of_match_table = flexcan_of_match,
1304	},
1305	.probe = flexcan_probe,
1306	.remove = flexcan_remove,
1307	.id_table = flexcan_id_table,
1308};
1309
1310module_platform_driver(flexcan_driver);
1311
1312MODULE_AUTHOR("Sascha Hauer <kernel@pengutronix.de>, "
1313	      "Marc Kleine-Budde <kernel@pengutronix.de>");
1314MODULE_LICENSE("GPL v2");
1315MODULE_DESCRIPTION("CAN port driver for flexcan based chip");