1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Socket CAN driver for Aeroflex Gaisler GRCAN and GRHCAN.
   4 *
   5 * 2012 (c) Aeroflex Gaisler AB
   6 *
   7 * This driver supports GRCAN and GRHCAN CAN controllers available in the GRLIB
   8 * VHDL IP core library.
   9 *
  10 * Full documentation of the GRCAN core can be found here:
  11 * http://www.gaisler.com/products/grlib/grip.pdf
  12 *
  13 * See "Documentation/devicetree/bindings/net/can/grcan.txt" for information on
  14 * open firmware properties.
  15 *
  16 * See "Documentation/ABI/testing/sysfs-class-net-grcan" for information on the
  17 * sysfs interface.
  18 *
  19 * See "Documentation/admin-guide/kernel-parameters.rst" for information on the module
  20 * parameters.
  21 *
  22 * Contributors: Andreas Larsson <andreas@gaisler.com>
  23 */
  24
  25#include <linux/kernel.h>
  26#include <linux/module.h>
  27#include <linux/interrupt.h>
  28#include <linux/netdevice.h>
  29#include <linux/delay.h>
  30#include <linux/ethtool.h>
  31#include <linux/io.h>
  32#include <linux/can/dev.h>
  33#include <linux/platform_device.h>
  34#include <linux/spinlock.h>
  35#include <linux/of.h>
  36#include <linux/of_irq.h>
  37
  38#include <linux/dma-mapping.h>
  39
  40#define DRV_NAME	"grcan"
  41
  42#define GRCAN_NAPI_WEIGHT	32
  43
  44#define GRCAN_RESERVE_SIZE(slot1, slot2) (((slot2) - (slot1)) / 4 - 1)
  45
  46struct grcan_registers {
  47	u32 conf;	/* 0x00 */
  48	u32 stat;	/* 0x04 */
  49	u32 ctrl;	/* 0x08 */
  50	u32 __reserved1[GRCAN_RESERVE_SIZE(0x08, 0x18)];
  51	u32 smask;	/* 0x18 - CanMASK */
  52	u32 scode;	/* 0x1c - CanCODE */
  53	u32 __reserved2[GRCAN_RESERVE_SIZE(0x1c, 0x100)];
  54	u32 pimsr;	/* 0x100 */
  55	u32 pimr;	/* 0x104 */
  56	u32 pisr;	/* 0x108 */
  57	u32 pir;	/* 0x10C */
  58	u32 imr;	/* 0x110 */
  59	u32 picr;	/* 0x114 */
  60	u32 __reserved3[GRCAN_RESERVE_SIZE(0x114, 0x200)];
  61	u32 txctrl;	/* 0x200 */
  62	u32 txaddr;	/* 0x204 */
  63	u32 txsize;	/* 0x208 */
  64	u32 txwr;	/* 0x20C */
  65	u32 txrd;	/* 0x210 */
  66	u32 txirq;	/* 0x214 */
  67	u32 __reserved4[GRCAN_RESERVE_SIZE(0x214, 0x300)];
  68	u32 rxctrl;	/* 0x300 */
  69	u32 rxaddr;	/* 0x304 */
  70	u32 rxsize;	/* 0x308 */
  71	u32 rxwr;	/* 0x30C */
  72	u32 rxrd;	/* 0x310 */
  73	u32 rxirq;	/* 0x314 */
  74	u32 rxmask;	/* 0x318 */
  75	u32 rxcode;	/* 0x31C */
  76};
  77
  78#define GRCAN_CONF_ABORT	0x00000001
  79#define GRCAN_CONF_ENABLE0	0x00000002
  80#define GRCAN_CONF_ENABLE1	0x00000004
  81#define GRCAN_CONF_SELECT	0x00000008
  82#define GRCAN_CONF_SILENT	0x00000010
  83#define GRCAN_CONF_SAM		0x00000020 /* Available in some hardware */
  84#define GRCAN_CONF_BPR		0x00000300 /* Note: not BRP */
  85#define GRCAN_CONF_RSJ		0x00007000
  86#define GRCAN_CONF_PS1		0x00f00000
  87#define GRCAN_CONF_PS2		0x000f0000
  88#define GRCAN_CONF_SCALER	0xff000000
  89#define GRCAN_CONF_OPERATION						\
  90	(GRCAN_CONF_ABORT | GRCAN_CONF_ENABLE0 | GRCAN_CONF_ENABLE1	\
  91	 | GRCAN_CONF_SELECT | GRCAN_CONF_SILENT | GRCAN_CONF_SAM)
  92#define GRCAN_CONF_TIMING						\
  93	(GRCAN_CONF_BPR | GRCAN_CONF_RSJ | GRCAN_CONF_PS1		\
  94	 | GRCAN_CONF_PS2 | GRCAN_CONF_SCALER)
  95
  96#define GRCAN_CONF_RSJ_MIN	1
  97#define GRCAN_CONF_RSJ_MAX	4
  98#define GRCAN_CONF_PS1_MIN	1
  99#define GRCAN_CONF_PS1_MAX	15
 100#define GRCAN_CONF_PS2_MIN	2
 101#define GRCAN_CONF_PS2_MAX	8
 102#define GRCAN_CONF_SCALER_MIN	0
 103#define GRCAN_CONF_SCALER_MAX	255
 104#define GRCAN_CONF_SCALER_INC	1
 105
 106#define GRCAN_CONF_BPR_BIT	8
 107#define GRCAN_CONF_RSJ_BIT	12
 108#define GRCAN_CONF_PS1_BIT	20
 109#define GRCAN_CONF_PS2_BIT	16
 110#define GRCAN_CONF_SCALER_BIT	24
 111
 112#define GRCAN_STAT_PASS		0x000001
 113#define GRCAN_STAT_OFF		0x000002
 114#define GRCAN_STAT_OR		0x000004
 115#define GRCAN_STAT_AHBERR	0x000008
 116#define GRCAN_STAT_ACTIVE	0x000010
 117#define GRCAN_STAT_RXERRCNT	0x00ff00
 118#define GRCAN_STAT_TXERRCNT	0xff0000
 119
 120#define GRCAN_STAT_ERRCTR_RELATED	(GRCAN_STAT_PASS | GRCAN_STAT_OFF)
 121
 122#define GRCAN_STAT_RXERRCNT_BIT	8
 123#define GRCAN_STAT_TXERRCNT_BIT	16
 124
 125#define GRCAN_STAT_ERRCNT_WARNING_LIMIT	96
 126#define GRCAN_STAT_ERRCNT_PASSIVE_LIMIT	127
 127
 128#define GRCAN_CTRL_RESET	0x2
 129#define GRCAN_CTRL_ENABLE	0x1
 130
 131#define GRCAN_TXCTRL_ENABLE	0x1
 132#define GRCAN_TXCTRL_ONGOING	0x2
 133#define GRCAN_TXCTRL_SINGLE	0x4
 134
 135#define GRCAN_RXCTRL_ENABLE	0x1
 136#define GRCAN_RXCTRL_ONGOING	0x2
 137
 138/* Relative offset of IRQ sources to AMBA Plug&Play */
 139#define GRCAN_IRQIX_IRQ		0
 140#define GRCAN_IRQIX_TXSYNC	1
 141#define GRCAN_IRQIX_RXSYNC	2
 142
 143#define GRCAN_IRQ_PASS		0x00001
 144#define GRCAN_IRQ_OFF		0x00002
 145#define GRCAN_IRQ_OR		0x00004
 146#define GRCAN_IRQ_RXAHBERR	0x00008
 147#define GRCAN_IRQ_TXAHBERR	0x00010
 148#define GRCAN_IRQ_RXIRQ		0x00020
 149#define GRCAN_IRQ_TXIRQ		0x00040
 150#define GRCAN_IRQ_RXFULL	0x00080
 151#define GRCAN_IRQ_TXEMPTY	0x00100
 152#define GRCAN_IRQ_RX		0x00200
 153#define GRCAN_IRQ_TX		0x00400
 154#define GRCAN_IRQ_RXSYNC	0x00800
 155#define GRCAN_IRQ_TXSYNC	0x01000
 156#define GRCAN_IRQ_RXERRCTR	0x02000
 157#define GRCAN_IRQ_TXERRCTR	0x04000
 158#define GRCAN_IRQ_RXMISS	0x08000
 159#define GRCAN_IRQ_TXLOSS	0x10000
 160
 161#define GRCAN_IRQ_NONE	0
 162#define GRCAN_IRQ_ALL							\
 163	(GRCAN_IRQ_PASS | GRCAN_IRQ_OFF | GRCAN_IRQ_OR			\
 164	 | GRCAN_IRQ_RXAHBERR | GRCAN_IRQ_TXAHBERR			\
 165	 | GRCAN_IRQ_RXIRQ | GRCAN_IRQ_TXIRQ				\
 166	 | GRCAN_IRQ_RXFULL | GRCAN_IRQ_TXEMPTY				\
 167	 | GRCAN_IRQ_RX | GRCAN_IRQ_TX | GRCAN_IRQ_RXSYNC		\
 168	 | GRCAN_IRQ_TXSYNC | GRCAN_IRQ_RXERRCTR			\
 169	 | GRCAN_IRQ_TXERRCTR | GRCAN_IRQ_RXMISS			\
 170	 | GRCAN_IRQ_TXLOSS)
 171
 172#define GRCAN_IRQ_ERRCTR_RELATED (GRCAN_IRQ_RXERRCTR | GRCAN_IRQ_TXERRCTR \
 173				  | GRCAN_IRQ_PASS | GRCAN_IRQ_OFF)
 174#define GRCAN_IRQ_ERRORS (GRCAN_IRQ_ERRCTR_RELATED | GRCAN_IRQ_OR	\
 175			  | GRCAN_IRQ_TXAHBERR | GRCAN_IRQ_RXAHBERR	\
 176			  | GRCAN_IRQ_TXLOSS)
 177#define GRCAN_IRQ_DEFAULT (GRCAN_IRQ_RX | GRCAN_IRQ_TX | GRCAN_IRQ_ERRORS)
 178
 179#define GRCAN_MSG_SIZE		16
 180
 181#define GRCAN_MSG_IDE		0x80000000
 182#define GRCAN_MSG_RTR		0x40000000
 183#define GRCAN_MSG_BID		0x1ffc0000
 184#define GRCAN_MSG_EID		0x1fffffff
 185#define GRCAN_MSG_IDE_BIT	31
 186#define GRCAN_MSG_RTR_BIT	30
 187#define GRCAN_MSG_BID_BIT	18
 188#define GRCAN_MSG_EID_BIT	0
 189
 190#define GRCAN_MSG_DLC		0xf0000000
 191#define GRCAN_MSG_TXERRC	0x00ff0000
 192#define GRCAN_MSG_RXERRC	0x0000ff00
 193#define GRCAN_MSG_DLC_BIT	28
 194#define GRCAN_MSG_TXERRC_BIT	16
 195#define GRCAN_MSG_RXERRC_BIT	8
 196#define GRCAN_MSG_AHBERR	0x00000008
 197#define GRCAN_MSG_OR		0x00000004
 198#define GRCAN_MSG_OFF		0x00000002
 199#define GRCAN_MSG_PASS		0x00000001
 200
 201#define GRCAN_MSG_DATA_SLOT_INDEX(i) (2 + (i) / 4)
 202#define GRCAN_MSG_DATA_SHIFT(i) ((3 - (i) % 4) * 8)
 203
 204#define GRCAN_BUFFER_ALIGNMENT		1024
 205#define GRCAN_DEFAULT_BUFFER_SIZE	1024
 206#define GRCAN_VALID_TR_SIZE_MASK	0x001fffc0
 207
 208#define GRCAN_INVALID_BUFFER_SIZE(s)			\
 209	((s) == 0 || ((s) & ~GRCAN_VALID_TR_SIZE_MASK))
 210
 211#if GRCAN_INVALID_BUFFER_SIZE(GRCAN_DEFAULT_BUFFER_SIZE)
 212#error "Invalid default buffer size"
 213#endif
 214
 215struct grcan_dma_buffer {
 216	size_t size;
 217	void *buf;
 218	dma_addr_t handle;
 219};
 220
 221struct grcan_dma {
 222	size_t base_size;
 223	void *base_buf;
 224	dma_addr_t base_handle;
 225	struct grcan_dma_buffer tx;
 226	struct grcan_dma_buffer rx;
 227};
 228
 229/* GRCAN configuration parameters */
 230struct grcan_device_config {
 231	unsigned short enable0;
 232	unsigned short enable1;
 233	unsigned short select;
 234	unsigned int txsize;
 235	unsigned int rxsize;
 236};
 237
 238#define GRCAN_DEFAULT_DEVICE_CONFIG {				\
 239		.enable0	= 0,				\
 240		.enable1	= 0,				\
 241		.select		= 0,				\
 242		.txsize		= GRCAN_DEFAULT_BUFFER_SIZE,	\
 243		.rxsize		= GRCAN_DEFAULT_BUFFER_SIZE,	\
 244		}
 245
 246#define GRCAN_TXBUG_SAFE_GRLIB_VERSION	4100
 247#define GRLIB_VERSION_MASK		0xffff
 248
 249/* GRCAN private data structure */
 250struct grcan_priv {
 251	struct can_priv can;	/* must be the first member */
 252	struct net_device *dev;
 253	struct device *ofdev_dev;
 254	struct napi_struct napi;
 255
 256	struct grcan_registers __iomem *regs;	/* ioremap'ed registers */
 257	struct grcan_device_config config;
 258	struct grcan_dma dma;
 259
 260	struct sk_buff **echo_skb;	/* We allocate this on our own */
 261
 262	/* The echo skb pointer, pointing into echo_skb and indicating which
 263	 * frames can be echoed back. See the "Notes on the tx cyclic buffer
 264	 * handling"-comment for grcan_start_xmit for more details.
 265	 */
 266	u32 eskbp;
 267
 268	/* Lock for controlling changes to the netif tx queue state, accesses to
 269	 * the echo_skb pointer eskbp and for making sure that a running reset
 270	 * and/or a close of the interface is done without interference from
 271	 * other parts of the code.
 272	 *
 273	 * The echo_skb pointer, eskbp, should only be accessed under this lock
 274	 * as it can be changed in several places and together with decisions on
 275	 * whether to wake up the tx queue.
 276	 *
 277	 * The tx queue must never be woken up if there is a running reset or
 278	 * close in progress.
 279	 *
 280	 * A running reset (see below on need_txbug_workaround) should never be
 281	 * done if the interface is closing down and several running resets
 282	 * should never be scheduled simultaneously.
 283	 */
 284	spinlock_t lock;
 285
 286	/* Whether a workaround is needed due to a bug in older hardware. In
 287	 * this case, the driver both tries to prevent the bug from being
 288	 * triggered and recovers, if the bug nevertheless happens, by doing a
 289	 * running reset. A running reset, resets the device and continues from
 290	 * where it were without being noticeable from outside the driver (apart
 291	 * from slight delays).
 292	 */
 293	bool need_txbug_workaround;
 294
 295	/* To trigger initization of running reset and to trigger running reset
 296	 * respectively in the case of a hanged device due to a txbug.
 297	 */
 298	struct timer_list hang_timer;
 299	struct timer_list rr_timer;
 300
 301	/* To avoid waking up the netif queue and restarting timers
 302	 * when a reset is scheduled or when closing of the device is
 303	 * undergoing
 304	 */
 305	bool resetting;
 306	bool closing;
 307};
 308
 309/* Wait time for a short wait for ongoing to clear */
 310#define GRCAN_SHORTWAIT_USECS	10
 311
 312/* Limit on the number of transmitted bits of an eff frame according to the CAN
 313 * specification: 1 bit start of frame, 32 bits arbitration field, 6 bits
 314 * control field, 8 bytes data field, 16 bits crc field, 2 bits ACK field and 7
 315 * bits end of frame
 316 */
 317#define GRCAN_EFF_FRAME_MAX_BITS	(1+32+6+8*8+16+2+7)
 318
 319#if defined(__BIG_ENDIAN)
 320static inline u32 grcan_read_reg(u32 __iomem *reg)
 321{
 322	return ioread32be(reg);
 323}
 324
 325static inline void grcan_write_reg(u32 __iomem *reg, u32 val)
 326{
 327	iowrite32be(val, reg);
 328}
 329#else
 330static inline u32 grcan_read_reg(u32 __iomem *reg)
 331{
 332	return ioread32(reg);
 333}
 334
 335static inline void grcan_write_reg(u32 __iomem *reg, u32 val)
 336{
 337	iowrite32(val, reg);
 338}
 339#endif
 340
 341static inline void grcan_clear_bits(u32 __iomem *reg, u32 mask)
 342{
 343	grcan_write_reg(reg, grcan_read_reg(reg) & ~mask);
 344}
 345
 346static inline void grcan_set_bits(u32 __iomem *reg, u32 mask)
 347{
 348	grcan_write_reg(reg, grcan_read_reg(reg) | mask);
 349}
 350
 351static inline u32 grcan_read_bits(u32 __iomem *reg, u32 mask)
 352{
 353	return grcan_read_reg(reg) & mask;
 354}
 355
 356static inline void grcan_write_bits(u32 __iomem *reg, u32 value, u32 mask)
 357{
 358	u32 old = grcan_read_reg(reg);
 359
 360	grcan_write_reg(reg, (old & ~mask) | (value & mask));
 361}
 362
 363/* a and b should both be in [0,size] and a == b == size should not hold */
 364static inline u32 grcan_ring_add(u32 a, u32 b, u32 size)
 365{
 366	u32 sum = a + b;
 367
 368	if (sum < size)
 369		return sum;
 370	else
 371		return sum - size;
 372}
 373
 374/* a and b should both be in [0,size) */
 375static inline u32 grcan_ring_sub(u32 a, u32 b, u32 size)
 376{
 377	return grcan_ring_add(a, size - b, size);
 378}
 379
 380/* Available slots for new transmissions */
 381static inline u32 grcan_txspace(size_t txsize, u32 txwr, u32 eskbp)
 382{
 383	u32 slots = txsize / GRCAN_MSG_SIZE - 1;
 384	u32 used = grcan_ring_sub(txwr, eskbp, txsize) / GRCAN_MSG_SIZE;
 385
 386	return slots - used;
 387}
 388
 389/* Configuration parameters that can be set via module parameters */
 390static struct grcan_device_config grcan_module_config =
 391	GRCAN_DEFAULT_DEVICE_CONFIG;
 392
 393static const struct can_bittiming_const grcan_bittiming_const = {
 394	.name		= DRV_NAME,
 395	.tseg1_min	= GRCAN_CONF_PS1_MIN + 1,
 396	.tseg1_max	= GRCAN_CONF_PS1_MAX + 1,
 397	.tseg2_min	= GRCAN_CONF_PS2_MIN,
 398	.tseg2_max	= GRCAN_CONF_PS2_MAX,
 399	.sjw_max	= GRCAN_CONF_RSJ_MAX,
 400	.brp_min	= GRCAN_CONF_SCALER_MIN + 1,
 401	.brp_max	= GRCAN_CONF_SCALER_MAX + 1,
 402	.brp_inc	= GRCAN_CONF_SCALER_INC,
 403};
 404
 405static int grcan_set_bittiming(struct net_device *dev)
 406{
 407	struct grcan_priv *priv = netdev_priv(dev);
 408	struct grcan_registers __iomem *regs = priv->regs;
 409	struct can_bittiming *bt = &priv->can.bittiming;
 410	u32 timing = 0;
 411	int bpr, rsj, ps1, ps2, scaler;
 412
 413	/* Should never happen - function will not be called when
 414	 * device is up
 415	 */
 416	if (grcan_read_bits(&regs->ctrl, GRCAN_CTRL_ENABLE))
 417		return -EBUSY;
 418
 419	bpr = 0; /* Note bpr and brp are different concepts */
 420	rsj = bt->sjw;
 421	ps1 = (bt->prop_seg + bt->phase_seg1) - 1; /* tseg1 - 1 */
 422	ps2 = bt->phase_seg2;
 423	scaler = (bt->brp - 1);
 424	netdev_dbg(dev, "Request for BPR=%d, RSJ=%d, PS1=%d, PS2=%d, SCALER=%d",
 425		   bpr, rsj, ps1, ps2, scaler);
 426	if (!(ps1 > ps2)) {
 427		netdev_err(dev, "PS1 > PS2 must hold: PS1=%d, PS2=%d\n",
 428			   ps1, ps2);
 429		return -EINVAL;
 430	}
 431	if (!(ps2 >= rsj)) {
 432		netdev_err(dev, "PS2 >= RSJ must hold: PS2=%d, RSJ=%d\n",
 433			   ps2, rsj);
 434		return -EINVAL;
 435	}
 436
 437	timing |= (bpr << GRCAN_CONF_BPR_BIT) & GRCAN_CONF_BPR;
 438	timing |= (rsj << GRCAN_CONF_RSJ_BIT) & GRCAN_CONF_RSJ;
 439	timing |= (ps1 << GRCAN_CONF_PS1_BIT) & GRCAN_CONF_PS1;
 440	timing |= (ps2 << GRCAN_CONF_PS2_BIT) & GRCAN_CONF_PS2;
 441	timing |= (scaler << GRCAN_CONF_SCALER_BIT) & GRCAN_CONF_SCALER;
 442	netdev_info(dev, "setting timing=0x%x\n", timing);
 443	grcan_write_bits(&regs->conf, timing, GRCAN_CONF_TIMING);
 444
 445	return 0;
 446}
 447
 448static int grcan_get_berr_counter(const struct net_device *dev,
 449				  struct can_berr_counter *bec)
 450{
 451	struct grcan_priv *priv = netdev_priv(dev);
 452	struct grcan_registers __iomem *regs = priv->regs;
 453	u32 status = grcan_read_reg(&regs->stat);
 454
 455	bec->txerr = (status & GRCAN_STAT_TXERRCNT) >> GRCAN_STAT_TXERRCNT_BIT;
 456	bec->rxerr = (status & GRCAN_STAT_RXERRCNT) >> GRCAN_STAT_RXERRCNT_BIT;
 457	return 0;
 458}
 459
 460static int grcan_poll(struct napi_struct *napi, int budget);
 461
 462/* Reset device, but keep configuration information */
 463static void grcan_reset(struct net_device *dev)
 464{
 465	struct grcan_priv *priv = netdev_priv(dev);
 466	struct grcan_registers __iomem *regs = priv->regs;
 467	u32 config = grcan_read_reg(&regs->conf);
 468
 469	grcan_set_bits(&regs->ctrl, GRCAN_CTRL_RESET);
 470	grcan_write_reg(&regs->conf, config);
 471
 472	priv->eskbp = grcan_read_reg(&regs->txrd);
 473	priv->can.state = CAN_STATE_STOPPED;
 474
 475	/* Turn off hardware filtering - regs->rxcode set to 0 by reset */
 476	grcan_write_reg(&regs->rxmask, 0);
 477}
 478
 479/* stop device without changing any configurations */
 480static void grcan_stop_hardware(struct net_device *dev)
 481{
 482	struct grcan_priv *priv = netdev_priv(dev);
 483	struct grcan_registers __iomem *regs = priv->regs;
 484
 485	grcan_write_reg(&regs->imr, GRCAN_IRQ_NONE);
 486	grcan_clear_bits(&regs->txctrl, GRCAN_TXCTRL_ENABLE);
 487	grcan_clear_bits(&regs->rxctrl, GRCAN_RXCTRL_ENABLE);
 488	grcan_clear_bits(&regs->ctrl, GRCAN_CTRL_ENABLE);
 489}
 490
 491/* Let priv->eskbp catch up to regs->txrd and echo back the skbs if echo
 492 * is true and free them otherwise.
 493 *
 494 * If budget is >= 0, stop after handling at most budget skbs. Otherwise,
 495 * continue until priv->eskbp catches up to regs->txrd.
 496 *
 497 * priv->lock *must* be held when calling this function
 498 */
 499static int catch_up_echo_skb(struct net_device *dev, int budget, bool echo)
 500{
 501	struct grcan_priv *priv = netdev_priv(dev);
 502	struct grcan_registers __iomem *regs = priv->regs;
 503	struct grcan_dma *dma = &priv->dma;
 504	struct net_device_stats *stats = &dev->stats;
 505	int i, work_done;
 506
 507	/* Updates to priv->eskbp and wake-ups of the queue needs to
 508	 * be atomic towards the reads of priv->eskbp and shut-downs
 509	 * of the queue in grcan_start_xmit.
 510	 */
 511	u32 txrd = grcan_read_reg(&regs->txrd);
 512
 513	for (work_done = 0; work_done < budget || budget < 0; work_done++) {
 514		if (priv->eskbp == txrd)
 515			break;
 516		i = priv->eskbp / GRCAN_MSG_SIZE;
 517		if (echo) {
 518			/* Normal echo of messages */
 519			stats->tx_packets++;
 520			stats->tx_bytes += can_get_echo_skb(dev, i, NULL);
 521		} else {
 522			/* For cleanup of untransmitted messages */
 523			can_free_echo_skb(dev, i, NULL);
 524		}
 525
 526		priv->eskbp = grcan_ring_add(priv->eskbp, GRCAN_MSG_SIZE,
 527					     dma->tx.size);
 528		txrd = grcan_read_reg(&regs->txrd);
 529	}
 530	return work_done;
 531}
 532
 533static void grcan_lost_one_shot_frame(struct net_device *dev)
 534{
 535	struct grcan_priv *priv = netdev_priv(dev);
 536	struct grcan_registers __iomem *regs = priv->regs;
 537	struct grcan_dma *dma = &priv->dma;
 538	u32 txrd;
 539	unsigned long flags;
 540
 541	spin_lock_irqsave(&priv->lock, flags);
 542
 543	catch_up_echo_skb(dev, -1, true);
 544
 545	if (unlikely(grcan_read_bits(&regs->txctrl, GRCAN_TXCTRL_ENABLE))) {
 546		/* Should never happen */
 547		netdev_err(dev, "TXCTRL enabled at TXLOSS in one shot mode\n");
 548	} else {
 549		/* By the time an GRCAN_IRQ_TXLOSS is generated in
 550		 * one-shot mode there is no problem in writing
 551		 * to TXRD even in versions of the hardware in
 552		 * which GRCAN_TXCTRL_ONGOING is not cleared properly
 553		 * in one-shot mode.
 554		 */
 555
 556		/* Skip message and discard echo-skb */
 557		txrd = grcan_read_reg(&regs->txrd);
 558		txrd = grcan_ring_add(txrd, GRCAN_MSG_SIZE, dma->tx.size);
 559		grcan_write_reg(&regs->txrd, txrd);
 560		catch_up_echo_skb(dev, -1, false);
 561
 562		if (!priv->resetting && !priv->closing &&
 563		    !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)) {
 564			netif_wake_queue(dev);
 565			grcan_set_bits(&regs->txctrl, GRCAN_TXCTRL_ENABLE);
 566		}
 567	}
 568
 569	spin_unlock_irqrestore(&priv->lock, flags);
 570}
 571
 572static void grcan_err(struct net_device *dev, u32 sources, u32 status)
 573{
 574	struct grcan_priv *priv = netdev_priv(dev);
 575	struct grcan_registers __iomem *regs = priv->regs;
 576	struct grcan_dma *dma = &priv->dma;
 577	struct net_device_stats *stats = &dev->stats;
 578	struct can_frame cf;
 579
 580	/* Zero potential error_frame */
 581	memset(&cf, 0, sizeof(cf));
 582
 583	/* Message lost interrupt. This might be due to arbitration error, but
 584	 * is also triggered when there is no one else on the can bus or when
 585	 * there is a problem with the hardware interface or the bus itself. As
 586	 * arbitration errors can not be singled out, no error frames are
 587	 * generated reporting this event as an arbitration error.
 588	 */
 589	if (sources & GRCAN_IRQ_TXLOSS) {
 590		/* Take care of failed one-shot transmit */
 591		if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
 592			grcan_lost_one_shot_frame(dev);
 593
 594		/* Stop printing as soon as error passive or bus off is in
 595		 * effect to limit the amount of txloss debug printouts.
 596		 */
 597		if (!(status & GRCAN_STAT_ERRCTR_RELATED)) {
 598			netdev_dbg(dev, "tx message lost\n");
 599			stats->tx_errors++;
 600		}
 601	}
 602
 603	/* Conditions dealing with the error counters. There is no interrupt for
 604	 * error warning, but there are interrupts for increases of the error
 605	 * counters.
 606	 */
 607	if ((sources & GRCAN_IRQ_ERRCTR_RELATED) ||
 608	    (status & GRCAN_STAT_ERRCTR_RELATED)) {
 609		enum can_state state = priv->can.state;
 610		enum can_state oldstate = state;
 611		u32 txerr = (status & GRCAN_STAT_TXERRCNT)
 612			>> GRCAN_STAT_TXERRCNT_BIT;
 613		u32 rxerr = (status & GRCAN_STAT_RXERRCNT)
 614			>> GRCAN_STAT_RXERRCNT_BIT;
 615
 616		/* Figure out current state */
 617		if (status & GRCAN_STAT_OFF) {
 618			state = CAN_STATE_BUS_OFF;
 619		} else if (status & GRCAN_STAT_PASS) {
 620			state = CAN_STATE_ERROR_PASSIVE;
 621		} else if (txerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT ||
 622			   rxerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT) {
 623			state = CAN_STATE_ERROR_WARNING;
 624		} else {
 625			state = CAN_STATE_ERROR_ACTIVE;
 626		}
 627
 628		/* Handle and report state changes */
 629		if (state != oldstate) {
 630			switch (state) {
 631			case CAN_STATE_BUS_OFF:
 632				netdev_dbg(dev, "bus-off\n");
 633				netif_carrier_off(dev);
 634				priv->can.can_stats.bus_off++;
 635
 636				/* Prevent the hardware from recovering from bus
 637				 * off on its own if restart is disabled.
 638				 */
 639				if (!priv->can.restart_ms)
 640					grcan_stop_hardware(dev);
 641
 642				cf.can_id |= CAN_ERR_BUSOFF;
 643				break;
 644
 645			case CAN_STATE_ERROR_PASSIVE:
 646				netdev_dbg(dev, "Error passive condition\n");
 647				priv->can.can_stats.error_passive++;
 648
 649				cf.can_id |= CAN_ERR_CRTL;
 650				if (txerr >= GRCAN_STAT_ERRCNT_PASSIVE_LIMIT)
 651					cf.data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
 652				if (rxerr >= GRCAN_STAT_ERRCNT_PASSIVE_LIMIT)
 653					cf.data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
 654				break;
 655
 656			case CAN_STATE_ERROR_WARNING:
 657				netdev_dbg(dev, "Error warning condition\n");
 658				priv->can.can_stats.error_warning++;
 659
 660				cf.can_id |= CAN_ERR_CRTL;
 661				if (txerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT)
 662					cf.data[1] |= CAN_ERR_CRTL_TX_WARNING;
 663				if (rxerr >= GRCAN_STAT_ERRCNT_WARNING_LIMIT)
 664					cf.data[1] |= CAN_ERR_CRTL_RX_WARNING;
 665				break;
 666
 667			case CAN_STATE_ERROR_ACTIVE:
 668				netdev_dbg(dev, "Error active condition\n");
 669				cf.can_id |= CAN_ERR_CRTL;
 670				break;
 671
 672			default:
 673				/* There are no others at this point */
 674				break;
 675			}
 676			cf.can_id |= CAN_ERR_CNT;
 677			cf.data[6] = txerr;
 678			cf.data[7] = rxerr;
 679			priv->can.state = state;
 680		}
 681
 682		/* Report automatic restarts */
 683		if (priv->can.restart_ms && oldstate == CAN_STATE_BUS_OFF) {
 684			unsigned long flags;
 685
 686			cf.can_id |= CAN_ERR_RESTARTED;
 687			netdev_dbg(dev, "restarted\n");
 688			priv->can.can_stats.restarts++;
 689			netif_carrier_on(dev);
 690
 691			spin_lock_irqsave(&priv->lock, flags);
 692
 693			if (!priv->resetting && !priv->closing) {
 694				u32 txwr = grcan_read_reg(&regs->txwr);
 695
 696				if (grcan_txspace(dma->tx.size, txwr,
 697						  priv->eskbp))
 698					netif_wake_queue(dev);
 699			}
 700
 701			spin_unlock_irqrestore(&priv->lock, flags);
 702		}
 703	}
 704
 705	/* Data overrun interrupt */
 706	if ((sources & GRCAN_IRQ_OR) || (status & GRCAN_STAT_OR)) {
 707		netdev_dbg(dev, "got data overrun interrupt\n");
 708		stats->rx_over_errors++;
 709		stats->rx_errors++;
 710
 711		cf.can_id |= CAN_ERR_CRTL;
 712		cf.data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
 713	}
 714
 715	/* AHB bus error interrupts (not CAN bus errors) - shut down the
 716	 * device.
 717	 */
 718	if (sources & (GRCAN_IRQ_TXAHBERR | GRCAN_IRQ_RXAHBERR) ||
 719	    (status & GRCAN_STAT_AHBERR)) {
 720		char *txrx = "";
 721		unsigned long flags;
 722
 723		if (sources & GRCAN_IRQ_TXAHBERR) {
 724			txrx = "on tx ";
 725			stats->tx_errors++;
 726		} else if (sources & GRCAN_IRQ_RXAHBERR) {
 727			txrx = "on rx ";
 728			stats->rx_errors++;
 729		}
 730		netdev_err(dev, "Fatal AHB bus error %s- halting device\n",
 731			   txrx);
 732
 733		spin_lock_irqsave(&priv->lock, flags);
 734
 735		/* Prevent anything to be enabled again and halt device */
 736		priv->closing = true;
 737		netif_stop_queue(dev);
 738		grcan_stop_hardware(dev);
 739		priv->can.state = CAN_STATE_STOPPED;
 740
 741		spin_unlock_irqrestore(&priv->lock, flags);
 742	}
 743
 744	/* Pass on error frame if something to report,
 745	 * i.e. id contains some information
 746	 */
 747	if (cf.can_id) {
 748		struct can_frame *skb_cf;
 749		struct sk_buff *skb = alloc_can_err_skb(dev, &skb_cf);
 750
 751		if (skb == NULL) {
 752			netdev_dbg(dev, "could not allocate error frame\n");
 753			return;
 754		}
 755		skb_cf->can_id |= cf.can_id;
 756		memcpy(skb_cf->data, cf.data, sizeof(cf.data));
 757
 758		netif_rx(skb);
 759	}
 760}
 761
 762static irqreturn_t grcan_interrupt(int irq, void *dev_id)
 763{
 764	struct net_device *dev = dev_id;
 765	struct grcan_priv *priv = netdev_priv(dev);
 766	struct grcan_registers __iomem *regs = priv->regs;
 767	u32 sources, status;
 768
 769	/* Find out the source */
 770	sources = grcan_read_reg(&regs->pimsr);
 771	if (!sources)
 772		return IRQ_NONE;
 773	grcan_write_reg(&regs->picr, sources);
 774	status = grcan_read_reg(&regs->stat);
 775
 776	/* If we got TX progress, the device has not hanged,
 777	 * so disable the hang timer
 778	 */
 779	if (priv->need_txbug_workaround &&
 780	    (sources & (GRCAN_IRQ_TX | GRCAN_IRQ_TXLOSS))) {
 781		del_timer(&priv->hang_timer);
 782	}
 783
 784	/* Frame(s) received or transmitted */
 785	if (sources & (GRCAN_IRQ_TX | GRCAN_IRQ_RX)) {
 786		/* Disable tx/rx interrupts and schedule poll(). No need for
 787		 * locking as interference from a running reset at worst leads
 788		 * to an extra interrupt.
 789		 */
 790		grcan_clear_bits(&regs->imr, GRCAN_IRQ_TX | GRCAN_IRQ_RX);
 791		napi_schedule(&priv->napi);
 792	}
 793
 794	/* (Potential) error conditions to take care of */
 795	if (sources & GRCAN_IRQ_ERRORS)
 796		grcan_err(dev, sources, status);
 797
 798	return IRQ_HANDLED;
 799}
 800
 801/* Reset device and restart operations from where they were.
 802 *
 803 * This assumes that RXCTRL & RXCTRL is properly disabled and that RX
 804 * is not ONGOING (TX might be stuck in ONGOING due to a harwrware bug
 805 * for single shot)
 806 */
 807static void grcan_running_reset(struct timer_list *t)
 808{
 809	struct grcan_priv *priv = from_timer(priv, t, rr_timer);
 810	struct net_device *dev = priv->dev;
 811	struct grcan_registers __iomem *regs = priv->regs;
 812	unsigned long flags;
 813
 814	/* This temporarily messes with eskbp, so we need to lock
 815	 * priv->lock
 816	 */
 817	spin_lock_irqsave(&priv->lock, flags);
 818
 819	priv->resetting = false;
 820	del_timer(&priv->hang_timer);
 821	del_timer(&priv->rr_timer);
 822
 823	if (!priv->closing) {
 824		/* Save and reset - config register preserved by grcan_reset */
 825		u32 imr = grcan_read_reg(&regs->imr);
 826
 827		u32 txaddr = grcan_read_reg(&regs->txaddr);
 828		u32 txsize = grcan_read_reg(&regs->txsize);
 829		u32 txwr = grcan_read_reg(&regs->txwr);
 830		u32 txrd = grcan_read_reg(&regs->txrd);
 831		u32 eskbp = priv->eskbp;
 832
 833		u32 rxaddr = grcan_read_reg(&regs->rxaddr);
 834		u32 rxsize = grcan_read_reg(&regs->rxsize);
 835		u32 rxwr = grcan_read_reg(&regs->rxwr);
 836		u32 rxrd = grcan_read_reg(&regs->rxrd);
 837
 838		grcan_reset(dev);
 839
 840		/* Restore */
 841		grcan_write_reg(&regs->txaddr, txaddr);
 842		grcan_write_reg(&regs->txsize, txsize);
 843		grcan_write_reg(&regs->txwr, txwr);
 844		grcan_write_reg(&regs->txrd, txrd);
 845		priv->eskbp = eskbp;
 846
 847		grcan_write_reg(&regs->rxaddr, rxaddr);
 848		grcan_write_reg(&regs->rxsize, rxsize);
 849		grcan_write_reg(&regs->rxwr, rxwr);
 850		grcan_write_reg(&regs->rxrd, rxrd);
 851
 852		/* Turn on device again */
 853		grcan_write_reg(&regs->imr, imr);
 854		priv->can.state = CAN_STATE_ERROR_ACTIVE;
 855		grcan_write_reg(&regs->txctrl, GRCAN_TXCTRL_ENABLE
 856				| (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT
 857				   ? GRCAN_TXCTRL_SINGLE : 0));
 858		grcan_write_reg(&regs->rxctrl, GRCAN_RXCTRL_ENABLE);
 859		grcan_write_reg(&regs->ctrl, GRCAN_CTRL_ENABLE);
 860
 861		/* Start queue if there is size and listen-onle mode is not
 862		 * enabled
 863		 */
 864		if (grcan_txspace(priv->dma.tx.size, txwr, priv->eskbp) &&
 865		    !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
 866			netif_wake_queue(dev);
 867	}
 868
 869	spin_unlock_irqrestore(&priv->lock, flags);
 870
 871	netdev_err(dev, "Device reset and restored\n");
 872}
 873
 874/* Waiting time in usecs corresponding to the transmission of three maximum
 875 * sized can frames in the given bitrate (in bits/sec). Waiting for this amount
 876 * of time makes sure that the can controller have time to finish sending or
 877 * receiving a frame with a good margin.
 878 *
 879 * usecs/sec * number of frames * bits/frame / bits/sec
 880 */
 881static inline u32 grcan_ongoing_wait_usecs(__u32 bitrate)
 882{
 883	return 1000000 * 3 * GRCAN_EFF_FRAME_MAX_BITS / bitrate;
 884}
 885
 886/* Set timer so that it will not fire until after a period in which the can
 887 * controller have a good margin to finish transmitting a frame unless it has
 888 * hanged
 889 */
 890static inline void grcan_reset_timer(struct timer_list *timer, __u32 bitrate)
 891{
 892	u32 wait_jiffies = usecs_to_jiffies(grcan_ongoing_wait_usecs(bitrate));
 893
 894	mod_timer(timer, jiffies + wait_jiffies);
 895}
 896
 897/* Disable channels and schedule a running reset */
 898static void grcan_initiate_running_reset(struct timer_list *t)
 899{
 900	struct grcan_priv *priv = from_timer(priv, t, hang_timer);
 901	struct net_device *dev = priv->dev;
 902	struct grcan_registers __iomem *regs = priv->regs;
 903	unsigned long flags;
 904
 905	netdev_err(dev, "Device seems hanged - reset scheduled\n");
 906
 907	spin_lock_irqsave(&priv->lock, flags);
 908
 909	/* The main body of this function must never be executed again
 910	 * until after an execution of grcan_running_reset
 911	 */
 912	if (!priv->resetting && !priv->closing) {
 913		priv->resetting = true;
 914		netif_stop_queue(dev);
 915		grcan_clear_bits(&regs->txctrl, GRCAN_TXCTRL_ENABLE);
 916		grcan_clear_bits(&regs->rxctrl, GRCAN_RXCTRL_ENABLE);
 917		grcan_reset_timer(&priv->rr_timer, priv->can.bittiming.bitrate);
 918	}
 919
 920	spin_unlock_irqrestore(&priv->lock, flags);
 921}
 922
 923static void grcan_free_dma_buffers(struct net_device *dev)
 924{
 925	struct grcan_priv *priv = netdev_priv(dev);
 926	struct grcan_dma *dma = &priv->dma;
 927
 928	dma_free_coherent(priv->ofdev_dev, dma->base_size, dma->base_buf,
 929			  dma->base_handle);
 930	memset(dma, 0, sizeof(*dma));
 931}
 932
 933static int grcan_allocate_dma_buffers(struct net_device *dev,
 934				      size_t tsize, size_t rsize)
 935{
 936	struct grcan_priv *priv = netdev_priv(dev);
 937	struct grcan_dma *dma = &priv->dma;
 938	struct grcan_dma_buffer *large = rsize > tsize ? &dma->rx : &dma->tx;
 939	struct grcan_dma_buffer *small = rsize > tsize ? &dma->tx : &dma->rx;
 940	size_t shift;
 941
 942	/* Need a whole number of GRCAN_BUFFER_ALIGNMENT for the large,
 943	 * i.e. first buffer
 944	 */
 945	size_t maxs = max(tsize, rsize);
 946	size_t lsize = ALIGN(maxs, GRCAN_BUFFER_ALIGNMENT);
 947
 948	/* Put the small buffer after that */
 949	size_t ssize = min(tsize, rsize);
 950
 951	/* Extra GRCAN_BUFFER_ALIGNMENT to allow for alignment */
 952	dma->base_size = lsize + ssize + GRCAN_BUFFER_ALIGNMENT;
 953	dma->base_buf = dma_alloc_coherent(priv->ofdev_dev,
 954					   dma->base_size,
 955					   &dma->base_handle,
 956					   GFP_KERNEL);
 957
 958	if (!dma->base_buf)
 959		return -ENOMEM;
 960
 961	dma->tx.size = tsize;
 962	dma->rx.size = rsize;
 963
 964	large->handle = ALIGN(dma->base_handle, GRCAN_BUFFER_ALIGNMENT);
 965	small->handle = large->handle + lsize;
 966	shift = large->handle - dma->base_handle;
 967
 968	large->buf = dma->base_buf + shift;
 969	small->buf = large->buf + lsize;
 970
 971	return 0;
 972}
 973
 974/* priv->lock *must* be held when calling this function */
 975static int grcan_start(struct net_device *dev)
 976{
 977	struct grcan_priv *priv = netdev_priv(dev);
 978	struct grcan_registers __iomem *regs = priv->regs;
 979	u32 confop, txctrl;
 980
 981	grcan_reset(dev);
 982
 983	grcan_write_reg(&regs->txaddr, priv->dma.tx.handle);
 984	grcan_write_reg(&regs->txsize, priv->dma.tx.size);
 985	/* regs->txwr, regs->txrd and priv->eskbp already set to 0 by reset */
 986
 987	grcan_write_reg(&regs->rxaddr, priv->dma.rx.handle);
 988	grcan_write_reg(&regs->rxsize, priv->dma.rx.size);
 989	/* regs->rxwr and regs->rxrd already set to 0 by reset */
 990
 991	/* Enable interrupts */
 992	grcan_read_reg(&regs->pir);
 993	grcan_write_reg(&regs->imr, GRCAN_IRQ_DEFAULT);
 994
 995	/* Enable interfaces, channels and device */
 996	confop = GRCAN_CONF_ABORT
 997		| (priv->config.enable0 ? GRCAN_CONF_ENABLE0 : 0)
 998		| (priv->config.enable1 ? GRCAN_CONF_ENABLE1 : 0)
 999		| (priv->config.select ? GRCAN_CONF_SELECT : 0)
1000		| (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY ?
1001		   GRCAN_CONF_SILENT : 0)
1002		| (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
1003		   GRCAN_CONF_SAM : 0);
1004	grcan_write_bits(&regs->conf, confop, GRCAN_CONF_OPERATION);
1005	txctrl = GRCAN_TXCTRL_ENABLE
1006		| (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT
1007		   ? GRCAN_TXCTRL_SINGLE : 0);
1008	grcan_write_reg(&regs->txctrl, txctrl);
1009	grcan_write_reg(&regs->rxctrl, GRCAN_RXCTRL_ENABLE);
1010	grcan_write_reg(&regs->ctrl, GRCAN_CTRL_ENABLE);
1011
1012	priv->can.state = CAN_STATE_ERROR_ACTIVE;
1013
1014	return 0;
1015}
1016
1017static int grcan_set_mode(struct net_device *dev, enum can_mode mode)
1018{
1019	struct grcan_priv *priv = netdev_priv(dev);
1020	unsigned long flags;
1021	int err = 0;
1022
1023	if (mode == CAN_MODE_START) {
1024		/* This might be called to restart the device to recover from
1025		 * bus off errors
1026		 */
1027		spin_lock_irqsave(&priv->lock, flags);
1028		if (priv->closing || priv->resetting) {
1029			err = -EBUSY;
1030		} else {
1031			netdev_info(dev, "Restarting device\n");
1032			grcan_start(dev);
1033			if (!(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
1034				netif_wake_queue(dev);
1035		}
1036		spin_unlock_irqrestore(&priv->lock, flags);
1037		return err;
1038	}
1039	return -EOPNOTSUPP;
1040}
1041
1042static int grcan_open(struct net_device *dev)
1043{
1044	struct grcan_priv *priv = netdev_priv(dev);
1045	struct grcan_dma *dma = &priv->dma;
1046	unsigned long flags;
1047	int err;
1048
1049	/* Allocate memory */
1050	err = grcan_allocate_dma_buffers(dev, priv->config.txsize,
1051					 priv->config.rxsize);
1052	if (err) {
1053		netdev_err(dev, "could not allocate DMA buffers\n");
1054		return err;
1055	}
1056
1057	priv->echo_skb = kcalloc(dma->tx.size, sizeof(*priv->echo_skb),
1058				 GFP_KERNEL);
1059	if (!priv->echo_skb) {
1060		err = -ENOMEM;
1061		goto exit_free_dma_buffers;
1062	}
1063	priv->can.echo_skb_max = dma->tx.size;
1064	priv->can.echo_skb = priv->echo_skb;
1065
1066	/* Get can device up */
1067	err = open_candev(dev);
1068	if (err)
1069		goto exit_free_echo_skb;
1070
1071	err = request_irq(dev->irq, grcan_interrupt, IRQF_SHARED,
1072			  dev->name, dev);
1073	if (err)
1074		goto exit_close_candev;
1075
1076	spin_lock_irqsave(&priv->lock, flags);
1077
1078	napi_enable(&priv->napi);
1079	grcan_start(dev);
1080	if (!(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
1081		netif_start_queue(dev);
1082	priv->resetting = false;
1083	priv->closing = false;
1084
1085	spin_unlock_irqrestore(&priv->lock, flags);
1086
1087	return 0;
1088
1089exit_close_candev:
1090	close_candev(dev);
1091exit_free_echo_skb:
1092	kfree(priv->echo_skb);
1093exit_free_dma_buffers:
1094	grcan_free_dma_buffers(dev);
1095	return err;
1096}
1097
1098static int grcan_close(struct net_device *dev)
1099{
1100	struct grcan_priv *priv = netdev_priv(dev);
1101	unsigned long flags;
1102
1103	napi_disable(&priv->napi);
1104
1105	spin_lock_irqsave(&priv->lock, flags);
1106
1107	priv->closing = true;
1108	if (priv->need_txbug_workaround) {
1109		spin_unlock_irqrestore(&priv->lock, flags);
1110		del_timer_sync(&priv->hang_timer);
1111		del_timer_sync(&priv->rr_timer);
1112		spin_lock_irqsave(&priv->lock, flags);
1113	}
1114	netif_stop_queue(dev);
1115	grcan_stop_hardware(dev);
1116	priv->can.state = CAN_STATE_STOPPED;
1117
1118	spin_unlock_irqrestore(&priv->lock, flags);
1119
1120	free_irq(dev->irq, dev);
1121	close_candev(dev);
1122
1123	grcan_free_dma_buffers(dev);
1124	priv->can.echo_skb_max = 0;
1125	priv->can.echo_skb = NULL;
1126	kfree(priv->echo_skb);
1127
1128	return 0;
1129}
1130
1131static void grcan_transmit_catch_up(struct net_device *dev)
1132{
1133	struct grcan_priv *priv = netdev_priv(dev);
1134	unsigned long flags;
1135	int work_done;
1136
1137	spin_lock_irqsave(&priv->lock, flags);
1138
1139	work_done = catch_up_echo_skb(dev, -1, true);
1140	if (work_done) {
1141		if (!priv->resetting && !priv->closing &&
1142		    !(priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY))
1143			netif_wake_queue(dev);
1144
1145		/* With napi we don't get TX interrupts for a while,
1146		 * so prevent a running reset while catching up
1147		 */
1148		if (priv->need_txbug_workaround)
1149			del_timer(&priv->hang_timer);
1150	}
1151
1152	spin_unlock_irqrestore(&priv->lock, flags);
1153}
1154
1155static int grcan_receive(struct net_device *dev, int budget)
1156{
1157	struct grcan_priv *priv = netdev_priv(dev);
1158	struct grcan_registers __iomem *regs = priv->regs;
1159	struct grcan_dma *dma = &priv->dma;
1160	struct net_device_stats *stats = &dev->stats;
1161	struct can_frame *cf;
1162	struct sk_buff *skb;
1163	u32 wr, rd, startrd;
1164	u32 *slot;
1165	u32 i, rtr, eff, j, shift;
1166	int work_done = 0;
1167
1168	rd = grcan_read_reg(&regs->rxrd);
1169	startrd = rd;
1170	for (work_done = 0; work_done < budget; work_done++) {
1171		/* Check for packet to receive */
1172		wr = grcan_read_reg(&regs->rxwr);
1173		if (rd == wr)
1174			break;
1175
1176		/* Take care of packet */
1177		skb = alloc_can_skb(dev, &cf);
1178		if (skb == NULL) {
1179			netdev_err(dev,
1180				   "dropping frame: skb allocation failed\n");
1181			stats->rx_dropped++;
1182			continue;
1183		}
1184
1185		slot = dma->rx.buf + rd;
1186		eff = slot[0] & GRCAN_MSG_IDE;
1187		rtr = slot[0] & GRCAN_MSG_RTR;
1188		if (eff) {
1189			cf->can_id = ((slot[0] & GRCAN_MSG_EID)
1190				      >> GRCAN_MSG_EID_BIT);
1191			cf->can_id |= CAN_EFF_FLAG;
1192		} else {
1193			cf->can_id = ((slot[0] & GRCAN_MSG_BID)
1194				      >> GRCAN_MSG_BID_BIT);
1195		}
1196		cf->len = can_cc_dlc2len((slot[1] & GRCAN_MSG_DLC)
1197					  >> GRCAN_MSG_DLC_BIT);
1198		if (rtr) {
1199			cf->can_id |= CAN_RTR_FLAG;
1200		} else {
1201			for (i = 0; i < cf->len; i++) {
1202				j = GRCAN_MSG_DATA_SLOT_INDEX(i);
1203				shift = GRCAN_MSG_DATA_SHIFT(i);
1204				cf->data[i] = (u8)(slot[j] >> shift);
1205			}
1206
1207			stats->rx_bytes += cf->len;
1208		}
1209		stats->rx_packets++;
1210
1211		netif_receive_skb(skb);
1212
1213		rd = grcan_ring_add(rd, GRCAN_MSG_SIZE, dma->rx.size);
1214	}
1215
1216	/* Make sure everything is read before allowing hardware to
1217	 * use the memory
1218	 */
1219	mb();
1220
1221	/* Update read pointer - no need to check for ongoing */
1222	if (likely(rd != startrd))
1223		grcan_write_reg(&regs->rxrd, rd);
1224
1225	return work_done;
1226}
1227
1228static int grcan_poll(struct napi_struct *napi, int budget)
1229{
1230	struct grcan_priv *priv = container_of(napi, struct grcan_priv, napi);
1231	struct net_device *dev = priv->dev;
1232	struct grcan_registers __iomem *regs = priv->regs;
1233	unsigned long flags;
1234	int work_done;
1235
1236	work_done = grcan_receive(dev, budget);
1237
1238	grcan_transmit_catch_up(dev);
1239
1240	if (work_done < budget) {
1241		napi_complete(napi);
1242
1243		/* Guarantee no interference with a running reset that otherwise
1244		 * could turn off interrupts.
1245		 */
1246		spin_lock_irqsave(&priv->lock, flags);
1247
1248		/* Enable tx and rx interrupts again. No need to check
1249		 * priv->closing as napi_disable in grcan_close is waiting for
1250		 * scheduled napi calls to finish.
1251		 */
1252		grcan_set_bits(&regs->imr, GRCAN_IRQ_TX | GRCAN_IRQ_RX);
1253
1254		spin_unlock_irqrestore(&priv->lock, flags);
1255	}
1256
1257	return work_done;
1258}
1259
1260/* Work tx bug by waiting while for the risky situation to clear. If that fails,
1261 * drop a frame in one-shot mode or indicate a busy device otherwise.
1262 *
1263 * Returns 0 on successful wait. Otherwise it sets *netdev_tx_status to the
1264 * value that should be returned by grcan_start_xmit when aborting the xmit.
1265 */
1266static int grcan_txbug_workaround(struct net_device *dev, struct sk_buff *skb,
1267				  u32 txwr, u32 oneshotmode,
1268				  netdev_tx_t *netdev_tx_status)
1269{
1270	struct grcan_priv *priv = netdev_priv(dev);
1271	struct grcan_registers __iomem *regs = priv->regs;
1272	struct grcan_dma *dma = &priv->dma;
1273	int i;
1274	unsigned long flags;
1275
1276	/* Wait a while for ongoing to be cleared or read pointer to catch up to
1277	 * write pointer. The latter is needed due to a bug in older versions of
1278	 * GRCAN in which ONGOING is not cleared properly one-shot mode when a
1279	 * transmission fails.
1280	 */
1281	for (i = 0; i < GRCAN_SHORTWAIT_USECS; i++) {
1282		udelay(1);
1283		if (!grcan_read_bits(&regs->txctrl, GRCAN_TXCTRL_ONGOING) ||
1284		    grcan_read_reg(&regs->txrd) == txwr) {
1285			return 0;
1286		}
1287	}
1288
1289	/* Clean up, in case the situation was not resolved */
1290	spin_lock_irqsave(&priv->lock, flags);
1291	if (!priv->resetting && !priv->closing) {
1292		/* Queue might have been stopped earlier in grcan_start_xmit */
1293		if (grcan_txspace(dma->tx.size, txwr, priv->eskbp))
1294			netif_wake_queue(dev);
1295		/* Set a timer to resolve a hanged tx controller */
1296		if (!timer_pending(&priv->hang_timer))
1297			grcan_reset_timer(&priv->hang_timer,
1298					  priv->can.bittiming.bitrate);
1299	}
1300	spin_unlock_irqrestore(&priv->lock, flags);
1301
1302	if (oneshotmode) {
1303		/* In one-shot mode we should never end up here because
1304		 * then the interrupt handler increases txrd on TXLOSS,
1305		 * but it is consistent with one-shot mode to drop the
1306		 * frame in this case.
1307		 */
1308		kfree_skb(skb);
1309		*netdev_tx_status = NETDEV_TX_OK;
1310	} else {
1311		/* In normal mode the socket-can transmission queue get
1312		 * to keep the frame so that it can be retransmitted
1313		 * later
1314		 */
1315		*netdev_tx_status = NETDEV_TX_BUSY;
1316	}
1317	return -EBUSY;
1318}
1319
1320/* Notes on the tx cyclic buffer handling:
1321 *
1322 * regs->txwr	- the next slot for the driver to put data to be sent
1323 * regs->txrd	- the next slot for the device to read data
1324 * priv->eskbp	- the next slot for the driver to call can_put_echo_skb for
1325 *
1326 * grcan_start_xmit can enter more messages as long as regs->txwr does
1327 * not reach priv->eskbp (within 1 message gap)
1328 *
1329 * The device sends messages until regs->txrd reaches regs->txwr
1330 *
1331 * The interrupt calls handler calls can_put_echo_skb until
1332 * priv->eskbp reaches regs->txrd
1333 */
1334static netdev_tx_t grcan_start_xmit(struct sk_buff *skb,
1335				    struct net_device *dev)
1336{
1337	struct grcan_priv *priv = netdev_priv(dev);
1338	struct grcan_registers __iomem *regs = priv->regs;
1339	struct grcan_dma *dma = &priv->dma;
1340	struct can_frame *cf = (struct can_frame *)skb->data;
1341	u32 id, txwr, txrd, space, txctrl;
1342	int slotindex;
1343	u32 *slot;
1344	u32 i, rtr, eff, dlc, tmp, err;
1345	int j, shift;
1346	unsigned long flags;
1347	u32 oneshotmode = priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT;
1348
1349	if (can_dev_dropped_skb(dev, skb))
1350		return NETDEV_TX_OK;
1351
1352	/* Trying to transmit in silent mode will generate error interrupts, but
1353	 * this should never happen - the queue should not have been started.
1354	 */
1355	if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
1356		return NETDEV_TX_BUSY;
1357
1358	/* Reads of priv->eskbp and shut-downs of the queue needs to
1359	 * be atomic towards the updates to priv->eskbp and wake-ups
1360	 * of the queue in the interrupt handler.
1361	 */
1362	spin_lock_irqsave(&priv->lock, flags);
1363
1364	txwr = grcan_read_reg(&regs->txwr);
1365	space = grcan_txspace(dma->tx.size, txwr, priv->eskbp);
1366
1367	slotindex = txwr / GRCAN_MSG_SIZE;
1368	slot = dma->tx.buf + txwr;
1369
1370	if (unlikely(space == 1))
1371		netif_stop_queue(dev);
1372
1373	spin_unlock_irqrestore(&priv->lock, flags);
1374	/* End of critical section*/
1375
1376	/* This should never happen. If circular buffer is full, the
1377	 * netif_stop_queue should have been stopped already.
1378	 */
1379	if (unlikely(!space)) {
1380		netdev_err(dev, "No buffer space, but queue is non-stopped.\n");
1381		return NETDEV_TX_BUSY;
1382	}
1383
1384	/* Convert and write CAN message to DMA buffer */
1385	eff = cf->can_id & CAN_EFF_FLAG;
1386	rtr = cf->can_id & CAN_RTR_FLAG;
1387	id = cf->can_id & (eff ? CAN_EFF_MASK : CAN_SFF_MASK);
1388	dlc = cf->len;
1389	if (eff)
1390		tmp = (id << GRCAN_MSG_EID_BIT) & GRCAN_MSG_EID;
1391	else
1392		tmp = (id << GRCAN_MSG_BID_BIT) & GRCAN_MSG_BID;
1393	slot[0] = (eff ? GRCAN_MSG_IDE : 0) | (rtr ? GRCAN_MSG_RTR : 0) | tmp;
1394
1395	slot[1] = ((dlc << GRCAN_MSG_DLC_BIT) & GRCAN_MSG_DLC);
1396	slot[2] = 0;
1397	slot[3] = 0;
1398	for (i = 0; i < dlc; i++) {
1399		j = GRCAN_MSG_DATA_SLOT_INDEX(i);
1400		shift = GRCAN_MSG_DATA_SHIFT(i);
1401		slot[j] |= cf->data[i] << shift;
1402	}
1403
1404	/* Checking that channel has not been disabled. These cases
1405	 * should never happen
1406	 */
1407	txctrl = grcan_read_reg(&regs->txctrl);
1408	if (!(txctrl & GRCAN_TXCTRL_ENABLE))
1409		netdev_err(dev, "tx channel spuriously disabled\n");
1410
1411	if (oneshotmode && !(txctrl & GRCAN_TXCTRL_SINGLE))
1412		netdev_err(dev, "one-shot mode spuriously disabled\n");
1413
1414	/* Bug workaround for old version of grcan where updating txwr
1415	 * in the same clock cycle as the controller updates txrd to
1416	 * the current txwr could hang the can controller
1417	 */
1418	if (priv->need_txbug_workaround) {
1419		txrd = grcan_read_reg(&regs->txrd);
1420		if (unlikely(grcan_ring_sub(txwr, txrd, dma->tx.size) == 1)) {
1421			netdev_tx_t txstatus;
1422
1423			err = grcan_txbug_workaround(dev, skb, txwr,
1424						     oneshotmode, &txstatus);
1425			if (err)
1426				return txstatus;
1427		}
1428	}
1429
1430	/* Prepare skb for echoing. This must be after the bug workaround above
1431	 * as ownership of the skb is passed on by calling can_put_echo_skb.
1432	 * Returning NETDEV_TX_BUSY or accessing skb or cf after a call to
1433	 * can_put_echo_skb would be an error unless other measures are
1434	 * taken.
1435	 */
1436	can_put_echo_skb(skb, dev, slotindex, 0);
1437
1438	/* Make sure everything is written before allowing hardware to
1439	 * read from the memory
1440	 */
1441	wmb();
1442
1443	/* Update write pointer to start transmission */
1444	grcan_write_reg(&regs->txwr,
1445			grcan_ring_add(txwr, GRCAN_MSG_SIZE, dma->tx.size));
1446
1447	return NETDEV_TX_OK;
1448}
1449
1450/* ========== Setting up sysfs interface and module parameters ========== */
1451
1452#define GRCAN_NOT_BOOL(unsigned_val) ((unsigned_val) > 1)
1453
1454#define GRCAN_MODULE_PARAM(name, mtype, valcheckf, desc)		\
1455	static void grcan_sanitize_##name(struct platform_device *pd)	\
1456	{								\
1457		struct grcan_device_config grcan_default_config		\
1458			= GRCAN_DEFAULT_DEVICE_CONFIG;			\
1459		if (valcheckf(grcan_module_config.name)) {		\
1460			dev_err(&pd->dev,				\
1461				"Invalid module parameter value for "	\
1462				#name " - setting default\n");		\
1463			grcan_module_config.name =			\
1464				grcan_default_config.name;		\
1465		}							\
1466	}								\
1467	module_param_named(name, grcan_module_config.name,		\
1468			   mtype, 0444);				\
1469	MODULE_PARM_DESC(name, desc)
1470
1471#define GRCAN_CONFIG_ATTR(name, desc)					\
1472	static ssize_t grcan_store_##name(struct device *sdev,		\
1473					  struct device_attribute *att,	\
1474					  const char *buf,		\
1475					  size_t count)			\
1476	{								\
1477		struct net_device *dev = to_net_dev(sdev);		\
1478		struct grcan_priv *priv = netdev_priv(dev);		\
1479		u8 val;							\
1480		int ret;						\
1481		if (dev->flags & IFF_UP)				\
1482			return -EBUSY;					\
1483		ret = kstrtou8(buf, 0, &val);				\
1484		if (ret < 0 || val > 1)					\
1485			return -EINVAL;					\
1486		priv->config.name = val;				\
1487		return count;						\
1488	}								\
1489	static ssize_t grcan_show_##name(struct device *sdev,		\
1490					 struct device_attribute *att,	\
1491					 char *buf)			\
1492	{								\
1493		struct net_device *dev = to_net_dev(sdev);		\
1494		struct grcan_priv *priv = netdev_priv(dev);		\
1495		return sprintf(buf, "%d\n", priv->config.name);		\
1496	}								\
1497	static DEVICE_ATTR(name, 0644,					\
1498			   grcan_show_##name,				\
1499			   grcan_store_##name);				\
1500	GRCAN_MODULE_PARAM(name, ushort, GRCAN_NOT_BOOL, desc)
1501
1502/* The following configuration options are made available both via module
1503 * parameters and writable sysfs files. See the chapter about GRCAN in the
1504 * documentation for the GRLIB VHDL library for further details.
1505 */
1506GRCAN_CONFIG_ATTR(enable0,
1507		  "Configuration of physical interface 0. Determines\n"	\
1508		  "the \"Enable 0\" bit of the configuration register.\n" \
1509		  "Format: 0 | 1\nDefault: 0\n");
1510
1511GRCAN_CONFIG_ATTR(enable1,
1512		  "Configuration of physical interface 1. Determines\n"	\
1513		  "the \"Enable 1\" bit of the configuration register.\n" \
1514		  "Format: 0 | 1\nDefault: 0\n");
1515
1516GRCAN_CONFIG_ATTR(select,
1517		  "Select which physical interface to use.\n"	\
1518		  "Format: 0 | 1\nDefault: 0\n");
1519
1520/* The tx and rx buffer size configuration options are only available via module
1521 * parameters.
1522 */
1523GRCAN_MODULE_PARAM(txsize, uint, GRCAN_INVALID_BUFFER_SIZE,
1524		   "Sets the size of the tx buffer.\n"			\
1525		   "Format: <unsigned int> where (txsize & ~0x1fffc0) == 0\n" \
1526		   "Default: 1024\n");
1527GRCAN_MODULE_PARAM(rxsize, uint, GRCAN_INVALID_BUFFER_SIZE,
1528		   "Sets the size of the rx buffer.\n"			\
1529		   "Format: <unsigned int> where (size & ~0x1fffc0) == 0\n" \
1530		   "Default: 1024\n");
1531
1532/* Function that makes sure that configuration done using
1533 * module parameters are set to valid values
1534 */
1535static void grcan_sanitize_module_config(struct platform_device *ofdev)
1536{
1537	grcan_sanitize_enable0(ofdev);
1538	grcan_sanitize_enable1(ofdev);
1539	grcan_sanitize_select(ofdev);
1540	grcan_sanitize_txsize(ofdev);
1541	grcan_sanitize_rxsize(ofdev);
1542}
1543
1544static const struct attribute *const sysfs_grcan_attrs[] = {
1545	/* Config attrs */
1546	&dev_attr_enable0.attr,
1547	&dev_attr_enable1.attr,
1548	&dev_attr_select.attr,
1549	NULL,
1550};
1551
1552static const struct attribute_group sysfs_grcan_group = {
1553	.name	= "grcan",
1554	.attrs	= (struct attribute **)sysfs_grcan_attrs,
1555};
1556
1557/* ========== Setting up the driver ========== */
1558
1559static const struct net_device_ops grcan_netdev_ops = {
1560	.ndo_open	= grcan_open,
1561	.ndo_stop	= grcan_close,
1562	.ndo_start_xmit	= grcan_start_xmit,
1563	.ndo_change_mtu = can_change_mtu,
1564};
1565
1566static const struct ethtool_ops grcan_ethtool_ops = {
1567	.get_ts_info = ethtool_op_get_ts_info,
1568};
1569
1570static int grcan_setup_netdev(struct platform_device *ofdev,
1571			      void __iomem *base,
1572			      int irq, u32 ambafreq, bool txbug)
1573{
1574	struct net_device *dev;
1575	struct grcan_priv *priv;
1576	struct grcan_registers __iomem *regs;
1577	int err;
1578
1579	dev = alloc_candev(sizeof(struct grcan_priv), 0);
1580	if (!dev)
1581		return -ENOMEM;
1582
1583	dev->irq = irq;
1584	dev->flags |= IFF_ECHO;
1585	dev->netdev_ops = &grcan_netdev_ops;
1586	dev->ethtool_ops = &grcan_ethtool_ops;
1587	dev->sysfs_groups[0] = &sysfs_grcan_group;
1588
1589	priv = netdev_priv(dev);
1590	memcpy(&priv->config, &grcan_module_config,
1591	       sizeof(struct grcan_device_config));
1592	priv->dev = dev;
1593	priv->ofdev_dev = &ofdev->dev;
1594	priv->regs = base;
1595	priv->can.bittiming_const = &grcan_bittiming_const;
1596	priv->can.do_set_bittiming = grcan_set_bittiming;
1597	priv->can.do_set_mode = grcan_set_mode;
1598	priv->can.do_get_berr_counter = grcan_get_berr_counter;
1599	priv->can.clock.freq = ambafreq;
1600	priv->can.ctrlmode_supported =
1601		CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_ONE_SHOT;
1602	priv->need_txbug_workaround = txbug;
1603
1604	/* Discover if triple sampling is supported by hardware */
1605	regs = priv->regs;
1606	grcan_set_bits(&regs->ctrl, GRCAN_CTRL_RESET);
1607	grcan_set_bits(&regs->conf, GRCAN_CONF_SAM);
1608	if (grcan_read_bits(&regs->conf, GRCAN_CONF_SAM)) {
1609		priv->can.ctrlmode_supported |= CAN_CTRLMODE_3_SAMPLES;
1610		dev_dbg(&ofdev->dev, "Hardware supports triple-sampling\n");
1611	}
1612
1613	spin_lock_init(&priv->lock);
1614
1615	if (priv->need_txbug_workaround) {
1616		timer_setup(&priv->rr_timer, grcan_running_reset, 0);
1617		timer_setup(&priv->hang_timer, grcan_initiate_running_reset, 0);
1618	}
1619
1620	netif_napi_add_weight(dev, &priv->napi, grcan_poll, GRCAN_NAPI_WEIGHT);
1621
1622	SET_NETDEV_DEV(dev, &ofdev->dev);
1623	dev_info(&ofdev->dev, "regs=0x%p, irq=%d, clock=%d\n",
1624		 priv->regs, dev->irq, priv->can.clock.freq);
1625
1626	err = register_candev(dev);
1627	if (err)
1628		goto exit_free_candev;
1629
1630	platform_set_drvdata(ofdev, dev);
1631
1632	/* Reset device to allow bit-timing to be set. No need to call
1633	 * grcan_reset at this stage. That is done in grcan_open.
1634	 */
1635	grcan_write_reg(&regs->ctrl, GRCAN_CTRL_RESET);
1636
1637	return 0;
1638exit_free_candev:
1639	free_candev(dev);
1640	return err;
1641}
1642
1643static int grcan_probe(struct platform_device *ofdev)
1644{
1645	struct device_node *np = ofdev->dev.of_node;
1646	struct device_node *sysid_parent;
1647	u32 sysid, ambafreq;
1648	int irq, err;
1649	void __iomem *base;
1650	bool txbug = true;
1651
1652	/* Compare GRLIB version number with the first that does not
1653	 * have the tx bug (see start_xmit)
1654	 */
1655	sysid_parent = of_find_node_by_path("/ambapp0");
1656	if (sysid_parent) {
1657		err = of_property_read_u32(sysid_parent, "systemid", &sysid);
1658		if (!err && ((sysid & GRLIB_VERSION_MASK) >=
1659			     GRCAN_TXBUG_SAFE_GRLIB_VERSION))
1660			txbug = false;
1661		of_node_put(sysid_parent);
1662	}
1663
1664	err = of_property_read_u32(np, "freq", &ambafreq);
1665	if (err) {
1666		dev_err(&ofdev->dev, "unable to fetch \"freq\" property\n");
1667		goto exit_error;
1668	}
1669
1670	base = devm_platform_ioremap_resource(ofdev, 0);
1671	if (IS_ERR(base)) {
1672		err = PTR_ERR(base);
1673		goto exit_error;
1674	}
1675
1676	irq = irq_of_parse_and_map(np, GRCAN_IRQIX_IRQ);
1677	if (!irq) {
1678		dev_err(&ofdev->dev, "no irq found\n");
1679		err = -ENODEV;
1680		goto exit_error;
1681	}
1682
1683	grcan_sanitize_module_config(ofdev);
1684
1685	err = grcan_setup_netdev(ofdev, base, irq, ambafreq, txbug);
1686	if (err)
1687		goto exit_dispose_irq;
1688
1689	return 0;
1690
1691exit_dispose_irq:
1692	irq_dispose_mapping(irq);
1693exit_error:
1694	dev_err(&ofdev->dev,
1695		"%s socket CAN driver initialization failed with error %d\n",
1696		DRV_NAME, err);
1697	return err;
1698}
1699
1700static void grcan_remove(struct platform_device *ofdev)
1701{
1702	struct net_device *dev = platform_get_drvdata(ofdev);
1703	struct grcan_priv *priv = netdev_priv(dev);
1704
1705	unregister_candev(dev); /* Will in turn call grcan_close */
1706
1707	irq_dispose_mapping(dev->irq);
1708	netif_napi_del(&priv->napi);
1709	free_candev(dev);
 
 
1710}
1711
1712static const struct of_device_id grcan_match[] = {
1713	{.name = "GAISLER_GRCAN"},
1714	{.name = "01_03d"},
1715	{.name = "GAISLER_GRHCAN"},
1716	{.name = "01_034"},
1717	{},
1718};
1719
1720MODULE_DEVICE_TABLE(of, grcan_match);
1721
1722static struct platform_driver grcan_driver = {
1723	.driver = {
1724		.name = DRV_NAME,
1725		.of_match_table = grcan_match,
1726	},
1727	.probe = grcan_probe,
1728	.remove_new = grcan_remove,
1729};
1730
1731module_platform_driver(grcan_driver);
1732
1733MODULE_AUTHOR("Aeroflex Gaisler AB.");
1734MODULE_DESCRIPTION("Socket CAN driver for Aeroflex Gaisler GRCAN");
1735MODULE_LICENSE("GPL");