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   1/* Xilinx CAN device driver
   2 *
   3 * Copyright (C) 2012 - 2014 Xilinx, Inc.
   4 * Copyright (C) 2009 PetaLogix. All rights reserved.
   5 *
   6 * Description:
   7 * This driver is developed for Axi CAN IP and for Zynq CANPS Controller.
   8 * This program is free software: you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation, either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 */
  18
  19#include <linux/clk.h>
  20#include <linux/errno.h>
  21#include <linux/init.h>
  22#include <linux/interrupt.h>
  23#include <linux/io.h>
  24#include <linux/kernel.h>
  25#include <linux/module.h>
  26#include <linux/netdevice.h>
  27#include <linux/of.h>
  28#include <linux/platform_device.h>
  29#include <linux/skbuff.h>
  30#include <linux/string.h>
  31#include <linux/types.h>
  32#include <linux/can/dev.h>
  33#include <linux/can/error.h>
  34#include <linux/can/led.h>
  35#include <linux/pm_runtime.h>
  36
  37#define DRIVER_NAME	"xilinx_can"
  38
  39/* CAN registers set */
  40enum xcan_reg {
  41	XCAN_SRR_OFFSET		= 0x00, /* Software reset */
  42	XCAN_MSR_OFFSET		= 0x04, /* Mode select */
  43	XCAN_BRPR_OFFSET	= 0x08, /* Baud rate prescaler */
  44	XCAN_BTR_OFFSET		= 0x0C, /* Bit timing */
  45	XCAN_ECR_OFFSET		= 0x10, /* Error counter */
  46	XCAN_ESR_OFFSET		= 0x14, /* Error status */
  47	XCAN_SR_OFFSET		= 0x18, /* Status */
  48	XCAN_ISR_OFFSET		= 0x1C, /* Interrupt status */
  49	XCAN_IER_OFFSET		= 0x20, /* Interrupt enable */
  50	XCAN_ICR_OFFSET		= 0x24, /* Interrupt clear */
  51	XCAN_TXFIFO_ID_OFFSET	= 0x30,/* TX FIFO ID */
  52	XCAN_TXFIFO_DLC_OFFSET	= 0x34, /* TX FIFO DLC */
  53	XCAN_TXFIFO_DW1_OFFSET	= 0x38, /* TX FIFO Data Word 1 */
  54	XCAN_TXFIFO_DW2_OFFSET	= 0x3C, /* TX FIFO Data Word 2 */
  55	XCAN_RXFIFO_ID_OFFSET	= 0x50, /* RX FIFO ID */
  56	XCAN_RXFIFO_DLC_OFFSET	= 0x54, /* RX FIFO DLC */
  57	XCAN_RXFIFO_DW1_OFFSET	= 0x58, /* RX FIFO Data Word 1 */
  58	XCAN_RXFIFO_DW2_OFFSET	= 0x5C, /* RX FIFO Data Word 2 */
  59};
  60
  61/* CAN register bit masks - XCAN_<REG>_<BIT>_MASK */
  62#define XCAN_SRR_CEN_MASK		0x00000002 /* CAN enable */
  63#define XCAN_SRR_RESET_MASK		0x00000001 /* Soft Reset the CAN core */
  64#define XCAN_MSR_LBACK_MASK		0x00000002 /* Loop back mode select */
  65#define XCAN_MSR_SLEEP_MASK		0x00000001 /* Sleep mode select */
  66#define XCAN_BRPR_BRP_MASK		0x000000FF /* Baud rate prescaler */
  67#define XCAN_BTR_SJW_MASK		0x00000180 /* Synchronous jump width */
  68#define XCAN_BTR_TS2_MASK		0x00000070 /* Time segment 2 */
  69#define XCAN_BTR_TS1_MASK		0x0000000F /* Time segment 1 */
  70#define XCAN_ECR_REC_MASK		0x0000FF00 /* Receive error counter */
  71#define XCAN_ECR_TEC_MASK		0x000000FF /* Transmit error counter */
  72#define XCAN_ESR_ACKER_MASK		0x00000010 /* ACK error */
  73#define XCAN_ESR_BERR_MASK		0x00000008 /* Bit error */
  74#define XCAN_ESR_STER_MASK		0x00000004 /* Stuff error */
  75#define XCAN_ESR_FMER_MASK		0x00000002 /* Form error */
  76#define XCAN_ESR_CRCER_MASK		0x00000001 /* CRC error */
  77#define XCAN_SR_TXFLL_MASK		0x00000400 /* TX FIFO is full */
  78#define XCAN_SR_ESTAT_MASK		0x00000180 /* Error status */
  79#define XCAN_SR_ERRWRN_MASK		0x00000040 /* Error warning */
  80#define XCAN_SR_NORMAL_MASK		0x00000008 /* Normal mode */
  81#define XCAN_SR_LBACK_MASK		0x00000002 /* Loop back mode */
  82#define XCAN_SR_CONFIG_MASK		0x00000001 /* Configuration mode */
  83#define XCAN_IXR_TXFEMP_MASK		0x00004000 /* TX FIFO Empty */
  84#define XCAN_IXR_WKUP_MASK		0x00000800 /* Wake up interrupt */
  85#define XCAN_IXR_SLP_MASK		0x00000400 /* Sleep interrupt */
  86#define XCAN_IXR_BSOFF_MASK		0x00000200 /* Bus off interrupt */
  87#define XCAN_IXR_ERROR_MASK		0x00000100 /* Error interrupt */
  88#define XCAN_IXR_RXNEMP_MASK		0x00000080 /* RX FIFO NotEmpty intr */
  89#define XCAN_IXR_RXOFLW_MASK		0x00000040 /* RX FIFO Overflow intr */
  90#define XCAN_IXR_RXOK_MASK		0x00000010 /* Message received intr */
  91#define XCAN_IXR_TXFLL_MASK		0x00000004 /* Tx FIFO Full intr */
  92#define XCAN_IXR_TXOK_MASK		0x00000002 /* TX successful intr */
  93#define XCAN_IXR_ARBLST_MASK		0x00000001 /* Arbitration lost intr */
  94#define XCAN_IDR_ID1_MASK		0xFFE00000 /* Standard msg identifier */
  95#define XCAN_IDR_SRR_MASK		0x00100000 /* Substitute remote TXreq */
  96#define XCAN_IDR_IDE_MASK		0x00080000 /* Identifier extension */
  97#define XCAN_IDR_ID2_MASK		0x0007FFFE /* Extended message ident */
  98#define XCAN_IDR_RTR_MASK		0x00000001 /* Remote TX request */
  99#define XCAN_DLCR_DLC_MASK		0xF0000000 /* Data length code */
 100
 101#define XCAN_INTR_ALL		(XCAN_IXR_TXOK_MASK | XCAN_IXR_BSOFF_MASK |\
 102				 XCAN_IXR_WKUP_MASK | XCAN_IXR_SLP_MASK | \
 103				 XCAN_IXR_RXNEMP_MASK | XCAN_IXR_ERROR_MASK | \
 104				 XCAN_IXR_ARBLST_MASK | XCAN_IXR_RXOK_MASK)
 105
 106/* CAN register bit shift - XCAN_<REG>_<BIT>_SHIFT */
 107#define XCAN_BTR_SJW_SHIFT		7  /* Synchronous jump width */
 108#define XCAN_BTR_TS2_SHIFT		4  /* Time segment 2 */
 109#define XCAN_IDR_ID1_SHIFT		21 /* Standard Messg Identifier */
 110#define XCAN_IDR_ID2_SHIFT		1  /* Extended Message Identifier */
 111#define XCAN_DLCR_DLC_SHIFT		28 /* Data length code */
 112#define XCAN_ESR_REC_SHIFT		8  /* Rx Error Count */
 113
 114/* CAN frame length constants */
 115#define XCAN_FRAME_MAX_DATA_LEN		8
 116#define XCAN_TIMEOUT			(1 * HZ)
 117
 118/**
 119 * struct xcan_priv - This definition define CAN driver instance
 120 * @can:			CAN private data structure.
 121 * @tx_head:			Tx CAN packets ready to send on the queue
 122 * @tx_tail:			Tx CAN packets successfully sended on the queue
 123 * @tx_max:			Maximum number packets the driver can send
 124 * @napi:			NAPI structure
 125 * @read_reg:			For reading data from CAN registers
 126 * @write_reg:			For writing data to CAN registers
 127 * @dev:			Network device data structure
 128 * @reg_base:			Ioremapped address to registers
 129 * @irq_flags:			For request_irq()
 130 * @bus_clk:			Pointer to struct clk
 131 * @can_clk:			Pointer to struct clk
 132 */
 133struct xcan_priv {
 134	struct can_priv can;
 135	unsigned int tx_head;
 136	unsigned int tx_tail;
 137	unsigned int tx_max;
 138	struct napi_struct napi;
 139	u32 (*read_reg)(const struct xcan_priv *priv, enum xcan_reg reg);
 140	void (*write_reg)(const struct xcan_priv *priv, enum xcan_reg reg,
 141			u32 val);
 142	struct device *dev;
 143	void __iomem *reg_base;
 144	unsigned long irq_flags;
 145	struct clk *bus_clk;
 146	struct clk *can_clk;
 147};
 148
 149/* CAN Bittiming constants as per Xilinx CAN specs */
 150static const struct can_bittiming_const xcan_bittiming_const = {
 151	.name = DRIVER_NAME,
 152	.tseg1_min = 1,
 153	.tseg1_max = 16,
 154	.tseg2_min = 1,
 155	.tseg2_max = 8,
 156	.sjw_max = 4,
 157	.brp_min = 1,
 158	.brp_max = 256,
 159	.brp_inc = 1,
 160};
 161
 162/**
 163 * xcan_write_reg_le - Write a value to the device register little endian
 164 * @priv:	Driver private data structure
 165 * @reg:	Register offset
 166 * @val:	Value to write at the Register offset
 167 *
 168 * Write data to the paricular CAN register
 169 */
 170static void xcan_write_reg_le(const struct xcan_priv *priv, enum xcan_reg reg,
 171			u32 val)
 172{
 173	iowrite32(val, priv->reg_base + reg);
 174}
 175
 176/**
 177 * xcan_read_reg_le - Read a value from the device register little endian
 178 * @priv:	Driver private data structure
 179 * @reg:	Register offset
 180 *
 181 * Read data from the particular CAN register
 182 * Return: value read from the CAN register
 183 */
 184static u32 xcan_read_reg_le(const struct xcan_priv *priv, enum xcan_reg reg)
 185{
 186	return ioread32(priv->reg_base + reg);
 187}
 188
 189/**
 190 * xcan_write_reg_be - Write a value to the device register big endian
 191 * @priv:	Driver private data structure
 192 * @reg:	Register offset
 193 * @val:	Value to write at the Register offset
 194 *
 195 * Write data to the paricular CAN register
 196 */
 197static void xcan_write_reg_be(const struct xcan_priv *priv, enum xcan_reg reg,
 198			u32 val)
 199{
 200	iowrite32be(val, priv->reg_base + reg);
 201}
 202
 203/**
 204 * xcan_read_reg_be - Read a value from the device register big endian
 205 * @priv:	Driver private data structure
 206 * @reg:	Register offset
 207 *
 208 * Read data from the particular CAN register
 209 * Return: value read from the CAN register
 210 */
 211static u32 xcan_read_reg_be(const struct xcan_priv *priv, enum xcan_reg reg)
 212{
 213	return ioread32be(priv->reg_base + reg);
 214}
 215
 216/**
 217 * set_reset_mode - Resets the CAN device mode
 218 * @ndev:	Pointer to net_device structure
 219 *
 220 * This is the driver reset mode routine.The driver
 221 * enters into configuration mode.
 222 *
 223 * Return: 0 on success and failure value on error
 224 */
 225static int set_reset_mode(struct net_device *ndev)
 226{
 227	struct xcan_priv *priv = netdev_priv(ndev);
 228	unsigned long timeout;
 229
 230	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
 231
 232	timeout = jiffies + XCAN_TIMEOUT;
 233	while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & XCAN_SR_CONFIG_MASK)) {
 234		if (time_after(jiffies, timeout)) {
 235			netdev_warn(ndev, "timed out for config mode\n");
 236			return -ETIMEDOUT;
 237		}
 238		usleep_range(500, 10000);
 239	}
 240
 241	return 0;
 242}
 243
 244/**
 245 * xcan_set_bittiming - CAN set bit timing routine
 246 * @ndev:	Pointer to net_device structure
 247 *
 248 * This is the driver set bittiming  routine.
 249 * Return: 0 on success and failure value on error
 250 */
 251static int xcan_set_bittiming(struct net_device *ndev)
 252{
 253	struct xcan_priv *priv = netdev_priv(ndev);
 254	struct can_bittiming *bt = &priv->can.bittiming;
 255	u32 btr0, btr1;
 256	u32 is_config_mode;
 257
 258	/* Check whether Xilinx CAN is in configuration mode.
 259	 * It cannot set bit timing if Xilinx CAN is not in configuration mode.
 260	 */
 261	is_config_mode = priv->read_reg(priv, XCAN_SR_OFFSET) &
 262				XCAN_SR_CONFIG_MASK;
 263	if (!is_config_mode) {
 264		netdev_alert(ndev,
 265		     "BUG! Cannot set bittiming - CAN is not in config mode\n");
 266		return -EPERM;
 267	}
 268
 269	/* Setting Baud Rate prescalar value in BRPR Register */
 270	btr0 = (bt->brp - 1);
 271
 272	/* Setting Time Segment 1 in BTR Register */
 273	btr1 = (bt->prop_seg + bt->phase_seg1 - 1);
 274
 275	/* Setting Time Segment 2 in BTR Register */
 276	btr1 |= (bt->phase_seg2 - 1) << XCAN_BTR_TS2_SHIFT;
 277
 278	/* Setting Synchronous jump width in BTR Register */
 279	btr1 |= (bt->sjw - 1) << XCAN_BTR_SJW_SHIFT;
 280
 281	priv->write_reg(priv, XCAN_BRPR_OFFSET, btr0);
 282	priv->write_reg(priv, XCAN_BTR_OFFSET, btr1);
 283
 284	netdev_dbg(ndev, "BRPR=0x%08x, BTR=0x%08x\n",
 285			priv->read_reg(priv, XCAN_BRPR_OFFSET),
 286			priv->read_reg(priv, XCAN_BTR_OFFSET));
 287
 288	return 0;
 289}
 290
 291/**
 292 * xcan_chip_start - This the drivers start routine
 293 * @ndev:	Pointer to net_device structure
 294 *
 295 * This is the drivers start routine.
 296 * Based on the State of the CAN device it puts
 297 * the CAN device into a proper mode.
 298 *
 299 * Return: 0 on success and failure value on error
 300 */
 301static int xcan_chip_start(struct net_device *ndev)
 302{
 303	struct xcan_priv *priv = netdev_priv(ndev);
 304	u32 reg_msr, reg_sr_mask;
 305	int err;
 306	unsigned long timeout;
 307
 308	/* Check if it is in reset mode */
 309	err = set_reset_mode(ndev);
 310	if (err < 0)
 311		return err;
 312
 313	err = xcan_set_bittiming(ndev);
 314	if (err < 0)
 315		return err;
 316
 317	/* Enable interrupts */
 318	priv->write_reg(priv, XCAN_IER_OFFSET, XCAN_INTR_ALL);
 319
 320	/* Check whether it is loopback mode or normal mode  */
 321	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 322		reg_msr = XCAN_MSR_LBACK_MASK;
 323		reg_sr_mask = XCAN_SR_LBACK_MASK;
 324	} else {
 325		reg_msr = 0x0;
 326		reg_sr_mask = XCAN_SR_NORMAL_MASK;
 327	}
 328
 329	priv->write_reg(priv, XCAN_MSR_OFFSET, reg_msr);
 330	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_CEN_MASK);
 331
 332	timeout = jiffies + XCAN_TIMEOUT;
 333	while (!(priv->read_reg(priv, XCAN_SR_OFFSET) & reg_sr_mask)) {
 334		if (time_after(jiffies, timeout)) {
 335			netdev_warn(ndev,
 336				"timed out for correct mode\n");
 337			return -ETIMEDOUT;
 338		}
 339	}
 340	netdev_dbg(ndev, "status:#x%08x\n",
 341			priv->read_reg(priv, XCAN_SR_OFFSET));
 342
 343	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 344	return 0;
 345}
 346
 347/**
 348 * xcan_do_set_mode - This sets the mode of the driver
 349 * @ndev:	Pointer to net_device structure
 350 * @mode:	Tells the mode of the driver
 351 *
 352 * This check the drivers state and calls the
 353 * the corresponding modes to set.
 354 *
 355 * Return: 0 on success and failure value on error
 356 */
 357static int xcan_do_set_mode(struct net_device *ndev, enum can_mode mode)
 358{
 359	int ret;
 360
 361	switch (mode) {
 362	case CAN_MODE_START:
 363		ret = xcan_chip_start(ndev);
 364		if (ret < 0) {
 365			netdev_err(ndev, "xcan_chip_start failed!\n");
 366			return ret;
 367		}
 368		netif_wake_queue(ndev);
 369		break;
 370	default:
 371		ret = -EOPNOTSUPP;
 372		break;
 373	}
 374
 375	return ret;
 376}
 377
 378/**
 379 * xcan_start_xmit - Starts the transmission
 380 * @skb:	sk_buff pointer that contains data to be Txed
 381 * @ndev:	Pointer to net_device structure
 382 *
 383 * This function is invoked from upper layers to initiate transmission. This
 384 * function uses the next available free txbuff and populates their fields to
 385 * start the transmission.
 386 *
 387 * Return: 0 on success and failure value on error
 388 */
 389static int xcan_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 390{
 391	struct xcan_priv *priv = netdev_priv(ndev);
 392	struct net_device_stats *stats = &ndev->stats;
 393	struct can_frame *cf = (struct can_frame *)skb->data;
 394	u32 id, dlc, data[2] = {0, 0};
 395
 396	if (can_dropped_invalid_skb(ndev, skb))
 397		return NETDEV_TX_OK;
 398
 399	/* Check if the TX buffer is full */
 400	if (unlikely(priv->read_reg(priv, XCAN_SR_OFFSET) &
 401			XCAN_SR_TXFLL_MASK)) {
 402		netif_stop_queue(ndev);
 403		netdev_err(ndev, "BUG!, TX FIFO full when queue awake!\n");
 404		return NETDEV_TX_BUSY;
 405	}
 406
 407	/* Watch carefully on the bit sequence */
 408	if (cf->can_id & CAN_EFF_FLAG) {
 409		/* Extended CAN ID format */
 410		id = ((cf->can_id & CAN_EFF_MASK) << XCAN_IDR_ID2_SHIFT) &
 411			XCAN_IDR_ID2_MASK;
 412		id |= (((cf->can_id & CAN_EFF_MASK) >>
 413			(CAN_EFF_ID_BITS-CAN_SFF_ID_BITS)) <<
 414			XCAN_IDR_ID1_SHIFT) & XCAN_IDR_ID1_MASK;
 415
 416		/* The substibute remote TX request bit should be "1"
 417		 * for extended frames as in the Xilinx CAN datasheet
 418		 */
 419		id |= XCAN_IDR_IDE_MASK | XCAN_IDR_SRR_MASK;
 420
 421		if (cf->can_id & CAN_RTR_FLAG)
 422			/* Extended frames remote TX request */
 423			id |= XCAN_IDR_RTR_MASK;
 424	} else {
 425		/* Standard CAN ID format */
 426		id = ((cf->can_id & CAN_SFF_MASK) << XCAN_IDR_ID1_SHIFT) &
 427			XCAN_IDR_ID1_MASK;
 428
 429		if (cf->can_id & CAN_RTR_FLAG)
 430			/* Standard frames remote TX request */
 431			id |= XCAN_IDR_SRR_MASK;
 432	}
 433
 434	dlc = cf->can_dlc << XCAN_DLCR_DLC_SHIFT;
 435
 436	if (cf->can_dlc > 0)
 437		data[0] = be32_to_cpup((__be32 *)(cf->data + 0));
 438	if (cf->can_dlc > 4)
 439		data[1] = be32_to_cpup((__be32 *)(cf->data + 4));
 440
 441	can_put_echo_skb(skb, ndev, priv->tx_head % priv->tx_max);
 442	priv->tx_head++;
 443
 444	/* Write the Frame to Xilinx CAN TX FIFO */
 445	priv->write_reg(priv, XCAN_TXFIFO_ID_OFFSET, id);
 446	/* If the CAN frame is RTR frame this write triggers tranmission */
 447	priv->write_reg(priv, XCAN_TXFIFO_DLC_OFFSET, dlc);
 448	if (!(cf->can_id & CAN_RTR_FLAG)) {
 449		priv->write_reg(priv, XCAN_TXFIFO_DW1_OFFSET, data[0]);
 450		/* If the CAN frame is Standard/Extended frame this
 451		 * write triggers tranmission
 452		 */
 453		priv->write_reg(priv, XCAN_TXFIFO_DW2_OFFSET, data[1]);
 454		stats->tx_bytes += cf->can_dlc;
 455	}
 456
 457	/* Check if the TX buffer is full */
 458	if ((priv->tx_head - priv->tx_tail) == priv->tx_max)
 459		netif_stop_queue(ndev);
 460
 461	return NETDEV_TX_OK;
 462}
 463
 464/**
 465 * xcan_rx -  Is called from CAN isr to complete the received
 466 *		frame  processing
 467 * @ndev:	Pointer to net_device structure
 468 *
 469 * This function is invoked from the CAN isr(poll) to process the Rx frames. It
 470 * does minimal processing and invokes "netif_receive_skb" to complete further
 471 * processing.
 472 * Return: 1 on success and 0 on failure.
 473 */
 474static int xcan_rx(struct net_device *ndev)
 475{
 476	struct xcan_priv *priv = netdev_priv(ndev);
 477	struct net_device_stats *stats = &ndev->stats;
 478	struct can_frame *cf;
 479	struct sk_buff *skb;
 480	u32 id_xcan, dlc, data[2] = {0, 0};
 481
 482	skb = alloc_can_skb(ndev, &cf);
 483	if (unlikely(!skb)) {
 484		stats->rx_dropped++;
 485		return 0;
 486	}
 487
 488	/* Read a frame from Xilinx zynq CANPS */
 489	id_xcan = priv->read_reg(priv, XCAN_RXFIFO_ID_OFFSET);
 490	dlc = priv->read_reg(priv, XCAN_RXFIFO_DLC_OFFSET) >>
 491				XCAN_DLCR_DLC_SHIFT;
 492
 493	/* Change Xilinx CAN data length format to socketCAN data format */
 494	cf->can_dlc = get_can_dlc(dlc);
 495
 496	/* Change Xilinx CAN ID format to socketCAN ID format */
 497	if (id_xcan & XCAN_IDR_IDE_MASK) {
 498		/* The received frame is an Extended format frame */
 499		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >> 3;
 500		cf->can_id |= (id_xcan & XCAN_IDR_ID2_MASK) >>
 501				XCAN_IDR_ID2_SHIFT;
 502		cf->can_id |= CAN_EFF_FLAG;
 503		if (id_xcan & XCAN_IDR_RTR_MASK)
 504			cf->can_id |= CAN_RTR_FLAG;
 505	} else {
 506		/* The received frame is a standard format frame */
 507		cf->can_id = (id_xcan & XCAN_IDR_ID1_MASK) >>
 508				XCAN_IDR_ID1_SHIFT;
 509		if (id_xcan & XCAN_IDR_SRR_MASK)
 510			cf->can_id |= CAN_RTR_FLAG;
 511	}
 512
 513	/* DW1/DW2 must always be read to remove message from RXFIFO */
 514	data[0] = priv->read_reg(priv, XCAN_RXFIFO_DW1_OFFSET);
 515	data[1] = priv->read_reg(priv, XCAN_RXFIFO_DW2_OFFSET);
 516
 517	if (!(cf->can_id & CAN_RTR_FLAG)) {
 518		/* Change Xilinx CAN data format to socketCAN data format */
 519		if (cf->can_dlc > 0)
 520			*(__be32 *)(cf->data) = cpu_to_be32(data[0]);
 521		if (cf->can_dlc > 4)
 522			*(__be32 *)(cf->data + 4) = cpu_to_be32(data[1]);
 523	}
 524
 525	stats->rx_bytes += cf->can_dlc;
 526	stats->rx_packets++;
 527	netif_receive_skb(skb);
 528
 529	return 1;
 530}
 531
 532/**
 533 * xcan_err_interrupt - error frame Isr
 534 * @ndev:	net_device pointer
 535 * @isr:	interrupt status register value
 536 *
 537 * This is the CAN error interrupt and it will
 538 * check the the type of error and forward the error
 539 * frame to upper layers.
 540 */
 541static void xcan_err_interrupt(struct net_device *ndev, u32 isr)
 542{
 543	struct xcan_priv *priv = netdev_priv(ndev);
 544	struct net_device_stats *stats = &ndev->stats;
 545	struct can_frame *cf;
 546	struct sk_buff *skb;
 547	u32 err_status, status, txerr = 0, rxerr = 0;
 548
 549	skb = alloc_can_err_skb(ndev, &cf);
 550
 551	err_status = priv->read_reg(priv, XCAN_ESR_OFFSET);
 552	priv->write_reg(priv, XCAN_ESR_OFFSET, err_status);
 553	txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
 554	rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
 555			XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
 556	status = priv->read_reg(priv, XCAN_SR_OFFSET);
 557
 558	if (isr & XCAN_IXR_BSOFF_MASK) {
 559		priv->can.state = CAN_STATE_BUS_OFF;
 560		priv->can.can_stats.bus_off++;
 561		/* Leave device in Config Mode in bus-off state */
 562		priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
 563		can_bus_off(ndev);
 564		if (skb)
 565			cf->can_id |= CAN_ERR_BUSOFF;
 566	} else if ((status & XCAN_SR_ESTAT_MASK) == XCAN_SR_ESTAT_MASK) {
 567		priv->can.state = CAN_STATE_ERROR_PASSIVE;
 568		priv->can.can_stats.error_passive++;
 569		if (skb) {
 570			cf->can_id |= CAN_ERR_CRTL;
 571			cf->data[1] = (rxerr > 127) ?
 572					CAN_ERR_CRTL_RX_PASSIVE :
 573					CAN_ERR_CRTL_TX_PASSIVE;
 574			cf->data[6] = txerr;
 575			cf->data[7] = rxerr;
 576		}
 577	} else if (status & XCAN_SR_ERRWRN_MASK) {
 578		priv->can.state = CAN_STATE_ERROR_WARNING;
 579		priv->can.can_stats.error_warning++;
 580		if (skb) {
 581			cf->can_id |= CAN_ERR_CRTL;
 582			cf->data[1] |= (txerr > rxerr) ?
 583					CAN_ERR_CRTL_TX_WARNING :
 584					CAN_ERR_CRTL_RX_WARNING;
 585			cf->data[6] = txerr;
 586			cf->data[7] = rxerr;
 587		}
 588	}
 589
 590	/* Check for Arbitration lost interrupt */
 591	if (isr & XCAN_IXR_ARBLST_MASK) {
 592		priv->can.can_stats.arbitration_lost++;
 593		if (skb) {
 594			cf->can_id |= CAN_ERR_LOSTARB;
 595			cf->data[0] = CAN_ERR_LOSTARB_UNSPEC;
 596		}
 597	}
 598
 599	/* Check for RX FIFO Overflow interrupt */
 600	if (isr & XCAN_IXR_RXOFLW_MASK) {
 601		stats->rx_over_errors++;
 602		stats->rx_errors++;
 603		priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
 604		if (skb) {
 605			cf->can_id |= CAN_ERR_CRTL;
 606			cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
 607		}
 608	}
 609
 610	/* Check for error interrupt */
 611	if (isr & XCAN_IXR_ERROR_MASK) {
 612		if (skb)
 613			cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
 614
 615		/* Check for Ack error interrupt */
 616		if (err_status & XCAN_ESR_ACKER_MASK) {
 617			stats->tx_errors++;
 618			if (skb) {
 619				cf->can_id |= CAN_ERR_ACK;
 620				cf->data[3] = CAN_ERR_PROT_LOC_ACK;
 621			}
 622		}
 623
 624		/* Check for Bit error interrupt */
 625		if (err_status & XCAN_ESR_BERR_MASK) {
 626			stats->tx_errors++;
 627			if (skb) {
 628				cf->can_id |= CAN_ERR_PROT;
 629				cf->data[2] = CAN_ERR_PROT_BIT;
 630			}
 631		}
 632
 633		/* Check for Stuff error interrupt */
 634		if (err_status & XCAN_ESR_STER_MASK) {
 635			stats->rx_errors++;
 636			if (skb) {
 637				cf->can_id |= CAN_ERR_PROT;
 638				cf->data[2] = CAN_ERR_PROT_STUFF;
 639			}
 640		}
 641
 642		/* Check for Form error interrupt */
 643		if (err_status & XCAN_ESR_FMER_MASK) {
 644			stats->rx_errors++;
 645			if (skb) {
 646				cf->can_id |= CAN_ERR_PROT;
 647				cf->data[2] = CAN_ERR_PROT_FORM;
 648			}
 649		}
 650
 651		/* Check for CRC error interrupt */
 652		if (err_status & XCAN_ESR_CRCER_MASK) {
 653			stats->rx_errors++;
 654			if (skb) {
 655				cf->can_id |= CAN_ERR_PROT;
 656				cf->data[3] = CAN_ERR_PROT_LOC_CRC_SEQ;
 657			}
 658		}
 659			priv->can.can_stats.bus_error++;
 660	}
 661
 662	if (skb) {
 663		stats->rx_packets++;
 664		stats->rx_bytes += cf->can_dlc;
 665		netif_rx(skb);
 666	}
 667
 668	netdev_dbg(ndev, "%s: error status register:0x%x\n",
 669			__func__, priv->read_reg(priv, XCAN_ESR_OFFSET));
 670}
 671
 672/**
 673 * xcan_state_interrupt - It will check the state of the CAN device
 674 * @ndev:	net_device pointer
 675 * @isr:	interrupt status register value
 676 *
 677 * This will checks the state of the CAN device
 678 * and puts the device into appropriate state.
 679 */
 680static void xcan_state_interrupt(struct net_device *ndev, u32 isr)
 681{
 682	struct xcan_priv *priv = netdev_priv(ndev);
 683
 684	/* Check for Sleep interrupt if set put CAN device in sleep state */
 685	if (isr & XCAN_IXR_SLP_MASK)
 686		priv->can.state = CAN_STATE_SLEEPING;
 687
 688	/* Check for Wake up interrupt if set put CAN device in Active state */
 689	if (isr & XCAN_IXR_WKUP_MASK)
 690		priv->can.state = CAN_STATE_ERROR_ACTIVE;
 691}
 692
 693/**
 694 * xcan_rx_poll - Poll routine for rx packets (NAPI)
 695 * @napi:	napi structure pointer
 696 * @quota:	Max number of rx packets to be processed.
 697 *
 698 * This is the poll routine for rx part.
 699 * It will process the packets maximux quota value.
 700 *
 701 * Return: number of packets received
 702 */
 703static int xcan_rx_poll(struct napi_struct *napi, int quota)
 704{
 705	struct net_device *ndev = napi->dev;
 706	struct xcan_priv *priv = netdev_priv(ndev);
 707	u32 isr, ier;
 708	int work_done = 0;
 709
 710	isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 711	while ((isr & XCAN_IXR_RXNEMP_MASK) && (work_done < quota)) {
 712		if (isr & XCAN_IXR_RXOK_MASK) {
 713			priv->write_reg(priv, XCAN_ICR_OFFSET,
 714				XCAN_IXR_RXOK_MASK);
 715			work_done += xcan_rx(ndev);
 716		} else {
 717			priv->write_reg(priv, XCAN_ICR_OFFSET,
 718				XCAN_IXR_RXNEMP_MASK);
 719			break;
 720		}
 721		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_RXNEMP_MASK);
 722		isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 723	}
 724
 725	if (work_done)
 726		can_led_event(ndev, CAN_LED_EVENT_RX);
 727
 728	if (work_done < quota) {
 729		napi_complete_done(napi, work_done);
 730		ier = priv->read_reg(priv, XCAN_IER_OFFSET);
 731		ier |= (XCAN_IXR_RXOK_MASK | XCAN_IXR_RXNEMP_MASK);
 732		priv->write_reg(priv, XCAN_IER_OFFSET, ier);
 733	}
 734	return work_done;
 735}
 736
 737/**
 738 * xcan_tx_interrupt - Tx Done Isr
 739 * @ndev:	net_device pointer
 740 * @isr:	Interrupt status register value
 741 */
 742static void xcan_tx_interrupt(struct net_device *ndev, u32 isr)
 743{
 744	struct xcan_priv *priv = netdev_priv(ndev);
 745	struct net_device_stats *stats = &ndev->stats;
 746
 747	while ((priv->tx_head - priv->tx_tail > 0) &&
 748			(isr & XCAN_IXR_TXOK_MASK)) {
 749		priv->write_reg(priv, XCAN_ICR_OFFSET, XCAN_IXR_TXOK_MASK);
 750		can_get_echo_skb(ndev, priv->tx_tail %
 751					priv->tx_max);
 752		priv->tx_tail++;
 753		stats->tx_packets++;
 754		isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 755	}
 756	can_led_event(ndev, CAN_LED_EVENT_TX);
 757	netif_wake_queue(ndev);
 758}
 759
 760/**
 761 * xcan_interrupt - CAN Isr
 762 * @irq:	irq number
 763 * @dev_id:	device id poniter
 764 *
 765 * This is the xilinx CAN Isr. It checks for the type of interrupt
 766 * and invokes the corresponding ISR.
 767 *
 768 * Return:
 769 * IRQ_NONE - If CAN device is in sleep mode, IRQ_HANDLED otherwise
 770 */
 771static irqreturn_t xcan_interrupt(int irq, void *dev_id)
 772{
 773	struct net_device *ndev = (struct net_device *)dev_id;
 774	struct xcan_priv *priv = netdev_priv(ndev);
 775	u32 isr, ier;
 776
 777	/* Get the interrupt status from Xilinx CAN */
 778	isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
 779	if (!isr)
 780		return IRQ_NONE;
 781
 782	/* Check for the type of interrupt and Processing it */
 783	if (isr & (XCAN_IXR_SLP_MASK | XCAN_IXR_WKUP_MASK)) {
 784		priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_SLP_MASK |
 785				XCAN_IXR_WKUP_MASK));
 786		xcan_state_interrupt(ndev, isr);
 787	}
 788
 789	/* Check for Tx interrupt and Processing it */
 790	if (isr & XCAN_IXR_TXOK_MASK)
 791		xcan_tx_interrupt(ndev, isr);
 792
 793	/* Check for the type of error interrupt and Processing it */
 794	if (isr & (XCAN_IXR_ERROR_MASK | XCAN_IXR_RXOFLW_MASK |
 795			XCAN_IXR_BSOFF_MASK | XCAN_IXR_ARBLST_MASK)) {
 796		priv->write_reg(priv, XCAN_ICR_OFFSET, (XCAN_IXR_ERROR_MASK |
 797				XCAN_IXR_RXOFLW_MASK | XCAN_IXR_BSOFF_MASK |
 798				XCAN_IXR_ARBLST_MASK));
 799		xcan_err_interrupt(ndev, isr);
 800	}
 801
 802	/* Check for the type of receive interrupt and Processing it */
 803	if (isr & (XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK)) {
 804		ier = priv->read_reg(priv, XCAN_IER_OFFSET);
 805		ier &= ~(XCAN_IXR_RXNEMP_MASK | XCAN_IXR_RXOK_MASK);
 806		priv->write_reg(priv, XCAN_IER_OFFSET, ier);
 807		napi_schedule(&priv->napi);
 808	}
 809	return IRQ_HANDLED;
 810}
 811
 812/**
 813 * xcan_chip_stop - Driver stop routine
 814 * @ndev:	Pointer to net_device structure
 815 *
 816 * This is the drivers stop routine. It will disable the
 817 * interrupts and put the device into configuration mode.
 818 */
 819static void xcan_chip_stop(struct net_device *ndev)
 820{
 821	struct xcan_priv *priv = netdev_priv(ndev);
 822	u32 ier;
 823
 824	/* Disable interrupts and leave the can in configuration mode */
 825	ier = priv->read_reg(priv, XCAN_IER_OFFSET);
 826	ier &= ~XCAN_INTR_ALL;
 827	priv->write_reg(priv, XCAN_IER_OFFSET, ier);
 828	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
 829	priv->can.state = CAN_STATE_STOPPED;
 830}
 831
 832/**
 833 * xcan_open - Driver open routine
 834 * @ndev:	Pointer to net_device structure
 835 *
 836 * This is the driver open routine.
 837 * Return: 0 on success and failure value on error
 838 */
 839static int xcan_open(struct net_device *ndev)
 840{
 841	struct xcan_priv *priv = netdev_priv(ndev);
 842	int ret;
 843
 844	ret = pm_runtime_get_sync(priv->dev);
 845	if (ret < 0) {
 846		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
 847				__func__, ret);
 848		return ret;
 849	}
 850
 851	ret = request_irq(ndev->irq, xcan_interrupt, priv->irq_flags,
 852			ndev->name, ndev);
 853	if (ret < 0) {
 854		netdev_err(ndev, "irq allocation for CAN failed\n");
 855		goto err;
 856	}
 857
 858	/* Set chip into reset mode */
 859	ret = set_reset_mode(ndev);
 860	if (ret < 0) {
 861		netdev_err(ndev, "mode resetting failed!\n");
 862		goto err_irq;
 863	}
 864
 865	/* Common open */
 866	ret = open_candev(ndev);
 867	if (ret)
 868		goto err_irq;
 869
 870	ret = xcan_chip_start(ndev);
 871	if (ret < 0) {
 872		netdev_err(ndev, "xcan_chip_start failed!\n");
 873		goto err_candev;
 874	}
 875
 876	can_led_event(ndev, CAN_LED_EVENT_OPEN);
 877	napi_enable(&priv->napi);
 878	netif_start_queue(ndev);
 879
 880	return 0;
 881
 882err_candev:
 883	close_candev(ndev);
 884err_irq:
 885	free_irq(ndev->irq, ndev);
 886err:
 887	pm_runtime_put(priv->dev);
 888
 889	return ret;
 890}
 891
 892/**
 893 * xcan_close - Driver close routine
 894 * @ndev:	Pointer to net_device structure
 895 *
 896 * Return: 0 always
 897 */
 898static int xcan_close(struct net_device *ndev)
 899{
 900	struct xcan_priv *priv = netdev_priv(ndev);
 901
 902	netif_stop_queue(ndev);
 903	napi_disable(&priv->napi);
 904	xcan_chip_stop(ndev);
 905	free_irq(ndev->irq, ndev);
 906	close_candev(ndev);
 907
 908	can_led_event(ndev, CAN_LED_EVENT_STOP);
 909	pm_runtime_put(priv->dev);
 910
 911	return 0;
 912}
 913
 914/**
 915 * xcan_get_berr_counter - error counter routine
 916 * @ndev:	Pointer to net_device structure
 917 * @bec:	Pointer to can_berr_counter structure
 918 *
 919 * This is the driver error counter routine.
 920 * Return: 0 on success and failure value on error
 921 */
 922static int xcan_get_berr_counter(const struct net_device *ndev,
 923					struct can_berr_counter *bec)
 924{
 925	struct xcan_priv *priv = netdev_priv(ndev);
 926	int ret;
 927
 928	ret = pm_runtime_get_sync(priv->dev);
 929	if (ret < 0) {
 930		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
 931				__func__, ret);
 932		return ret;
 933	}
 934
 935	bec->txerr = priv->read_reg(priv, XCAN_ECR_OFFSET) & XCAN_ECR_TEC_MASK;
 936	bec->rxerr = ((priv->read_reg(priv, XCAN_ECR_OFFSET) &
 937			XCAN_ECR_REC_MASK) >> XCAN_ESR_REC_SHIFT);
 938
 939	pm_runtime_put(priv->dev);
 940
 941	return 0;
 942}
 943
 944
 945static const struct net_device_ops xcan_netdev_ops = {
 946	.ndo_open	= xcan_open,
 947	.ndo_stop	= xcan_close,
 948	.ndo_start_xmit	= xcan_start_xmit,
 949	.ndo_change_mtu	= can_change_mtu,
 950};
 951
 952/**
 953 * xcan_suspend - Suspend method for the driver
 954 * @dev:	Address of the device structure
 955 *
 956 * Put the driver into low power mode.
 957 * Return: 0 on success and failure value on error
 958 */
 959static int __maybe_unused xcan_suspend(struct device *dev)
 960{
 961	if (!device_may_wakeup(dev))
 962		return pm_runtime_force_suspend(dev);
 963
 964	return 0;
 965}
 966
 967/**
 968 * xcan_resume - Resume from suspend
 969 * @dev:	Address of the device structure
 970 *
 971 * Resume operation after suspend.
 972 * Return: 0 on success and failure value on error
 973 */
 974static int __maybe_unused xcan_resume(struct device *dev)
 975{
 976	if (!device_may_wakeup(dev))
 977		return pm_runtime_force_resume(dev);
 978
 979	return 0;
 980
 981}
 982
 983/**
 984 * xcan_runtime_suspend - Runtime suspend method for the driver
 985 * @dev:	Address of the device structure
 986 *
 987 * Put the driver into low power mode.
 988 * Return: 0 always
 989 */
 990static int __maybe_unused xcan_runtime_suspend(struct device *dev)
 991{
 992	struct net_device *ndev = dev_get_drvdata(dev);
 993	struct xcan_priv *priv = netdev_priv(ndev);
 994
 995	if (netif_running(ndev)) {
 996		netif_stop_queue(ndev);
 997		netif_device_detach(ndev);
 998	}
 999
1000	priv->write_reg(priv, XCAN_MSR_OFFSET, XCAN_MSR_SLEEP_MASK);
1001	priv->can.state = CAN_STATE_SLEEPING;
1002
1003	clk_disable_unprepare(priv->bus_clk);
1004	clk_disable_unprepare(priv->can_clk);
1005
1006	return 0;
1007}
1008
1009/**
1010 * xcan_runtime_resume - Runtime resume from suspend
1011 * @dev:	Address of the device structure
1012 *
1013 * Resume operation after suspend.
1014 * Return: 0 on success and failure value on error
1015 */
1016static int __maybe_unused xcan_runtime_resume(struct device *dev)
1017{
1018	struct net_device *ndev = dev_get_drvdata(dev);
1019	struct xcan_priv *priv = netdev_priv(ndev);
1020	int ret;
1021	u32 isr, status;
1022
1023	ret = clk_prepare_enable(priv->bus_clk);
1024	if (ret) {
1025		dev_err(dev, "Cannot enable clock.\n");
1026		return ret;
1027	}
1028	ret = clk_prepare_enable(priv->can_clk);
1029	if (ret) {
1030		dev_err(dev, "Cannot enable clock.\n");
1031		clk_disable_unprepare(priv->bus_clk);
1032		return ret;
1033	}
1034
1035	priv->write_reg(priv, XCAN_SRR_OFFSET, XCAN_SRR_RESET_MASK);
1036	isr = priv->read_reg(priv, XCAN_ISR_OFFSET);
1037	status = priv->read_reg(priv, XCAN_SR_OFFSET);
1038
1039	if (netif_running(ndev)) {
1040		if (isr & XCAN_IXR_BSOFF_MASK) {
1041			priv->can.state = CAN_STATE_BUS_OFF;
1042			priv->write_reg(priv, XCAN_SRR_OFFSET,
1043					XCAN_SRR_RESET_MASK);
1044		} else if ((status & XCAN_SR_ESTAT_MASK) ==
1045					XCAN_SR_ESTAT_MASK) {
1046			priv->can.state = CAN_STATE_ERROR_PASSIVE;
1047		} else if (status & XCAN_SR_ERRWRN_MASK) {
1048			priv->can.state = CAN_STATE_ERROR_WARNING;
1049		} else {
1050			priv->can.state = CAN_STATE_ERROR_ACTIVE;
1051		}
1052		netif_device_attach(ndev);
1053		netif_start_queue(ndev);
1054	}
1055
1056	return 0;
1057}
1058
1059static const struct dev_pm_ops xcan_dev_pm_ops = {
1060	SET_SYSTEM_SLEEP_PM_OPS(xcan_suspend, xcan_resume)
1061	SET_RUNTIME_PM_OPS(xcan_runtime_suspend, xcan_runtime_resume, NULL)
1062};
1063
1064/**
1065 * xcan_probe - Platform registration call
1066 * @pdev:	Handle to the platform device structure
1067 *
1068 * This function does all the memory allocation and registration for the CAN
1069 * device.
1070 *
1071 * Return: 0 on success and failure value on error
1072 */
1073static int xcan_probe(struct platform_device *pdev)
1074{
1075	struct resource *res; /* IO mem resources */
1076	struct net_device *ndev;
1077	struct xcan_priv *priv;
1078	void __iomem *addr;
1079	int ret, rx_max, tx_max;
1080
1081	/* Get the virtual base address for the device */
1082	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1083	addr = devm_ioremap_resource(&pdev->dev, res);
1084	if (IS_ERR(addr)) {
1085		ret = PTR_ERR(addr);
1086		goto err;
1087	}
1088
1089	ret = of_property_read_u32(pdev->dev.of_node, "tx-fifo-depth", &tx_max);
1090	if (ret < 0)
1091		goto err;
1092
1093	ret = of_property_read_u32(pdev->dev.of_node, "rx-fifo-depth", &rx_max);
1094	if (ret < 0)
1095		goto err;
1096
1097	/* Create a CAN device instance */
1098	ndev = alloc_candev(sizeof(struct xcan_priv), tx_max);
1099	if (!ndev)
1100		return -ENOMEM;
1101
1102	priv = netdev_priv(ndev);
1103	priv->dev = &pdev->dev;
1104	priv->can.bittiming_const = &xcan_bittiming_const;
1105	priv->can.do_set_mode = xcan_do_set_mode;
1106	priv->can.do_get_berr_counter = xcan_get_berr_counter;
1107	priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
1108					CAN_CTRLMODE_BERR_REPORTING;
1109	priv->reg_base = addr;
1110	priv->tx_max = tx_max;
1111
1112	/* Get IRQ for the device */
1113	ndev->irq = platform_get_irq(pdev, 0);
1114	ndev->flags |= IFF_ECHO;	/* We support local echo */
1115
1116	platform_set_drvdata(pdev, ndev);
1117	SET_NETDEV_DEV(ndev, &pdev->dev);
1118	ndev->netdev_ops = &xcan_netdev_ops;
1119
1120	/* Getting the CAN can_clk info */
1121	priv->can_clk = devm_clk_get(&pdev->dev, "can_clk");
1122	if (IS_ERR(priv->can_clk)) {
1123		dev_err(&pdev->dev, "Device clock not found.\n");
1124		ret = PTR_ERR(priv->can_clk);
1125		goto err_free;
1126	}
1127	/* Check for type of CAN device */
1128	if (of_device_is_compatible(pdev->dev.of_node,
1129				    "xlnx,zynq-can-1.0")) {
1130		priv->bus_clk = devm_clk_get(&pdev->dev, "pclk");
1131		if (IS_ERR(priv->bus_clk)) {
1132			dev_err(&pdev->dev, "bus clock not found\n");
1133			ret = PTR_ERR(priv->bus_clk);
1134			goto err_free;
1135		}
1136	} else {
1137		priv->bus_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
1138		if (IS_ERR(priv->bus_clk)) {
1139			dev_err(&pdev->dev, "bus clock not found\n");
1140			ret = PTR_ERR(priv->bus_clk);
1141			goto err_free;
1142		}
1143	}
1144
1145	priv->write_reg = xcan_write_reg_le;
1146	priv->read_reg = xcan_read_reg_le;
1147
1148	pm_runtime_enable(&pdev->dev);
1149	ret = pm_runtime_get_sync(&pdev->dev);
1150	if (ret < 0) {
1151		netdev_err(ndev, "%s: pm_runtime_get failed(%d)\n",
1152			__func__, ret);
1153		goto err_pmdisable;
1154	}
1155
1156	if (priv->read_reg(priv, XCAN_SR_OFFSET) != XCAN_SR_CONFIG_MASK) {
1157		priv->write_reg = xcan_write_reg_be;
1158		priv->read_reg = xcan_read_reg_be;
1159	}
1160
1161	priv->can.clock.freq = clk_get_rate(priv->can_clk);
1162
1163	netif_napi_add(ndev, &priv->napi, xcan_rx_poll, rx_max);
1164
1165	ret = register_candev(ndev);
1166	if (ret) {
1167		dev_err(&pdev->dev, "fail to register failed (err=%d)\n", ret);
1168		goto err_disableclks;
1169	}
1170
1171	devm_can_led_init(ndev);
1172
1173	pm_runtime_put(&pdev->dev);
1174
1175	netdev_dbg(ndev, "reg_base=0x%p irq=%d clock=%d, tx fifo depth:%d\n",
1176			priv->reg_base, ndev->irq, priv->can.clock.freq,
1177			priv->tx_max);
1178
1179	return 0;
1180
1181err_disableclks:
1182	pm_runtime_put(priv->dev);
1183err_pmdisable:
1184	pm_runtime_disable(&pdev->dev);
1185err_free:
1186	free_candev(ndev);
1187err:
1188	return ret;
1189}
1190
1191/**
1192 * xcan_remove - Unregister the device after releasing the resources
1193 * @pdev:	Handle to the platform device structure
1194 *
1195 * This function frees all the resources allocated to the device.
1196 * Return: 0 always
1197 */
1198static int xcan_remove(struct platform_device *pdev)
1199{
1200	struct net_device *ndev = platform_get_drvdata(pdev);
1201	struct xcan_priv *priv = netdev_priv(ndev);
1202
1203	unregister_candev(ndev);
1204	pm_runtime_disable(&pdev->dev);
1205	netif_napi_del(&priv->napi);
1206	free_candev(ndev);
1207
1208	return 0;
1209}
1210
1211/* Match table for OF platform binding */
1212static const struct of_device_id xcan_of_match[] = {
1213	{ .compatible = "xlnx,zynq-can-1.0", },
1214	{ .compatible = "xlnx,axi-can-1.00.a", },
1215	{ /* end of list */ },
1216};
1217MODULE_DEVICE_TABLE(of, xcan_of_match);
1218
1219static struct platform_driver xcan_driver = {
1220	.probe = xcan_probe,
1221	.remove	= xcan_remove,
1222	.driver	= {
1223		.name = DRIVER_NAME,
1224		.pm = &xcan_dev_pm_ops,
1225		.of_match_table	= xcan_of_match,
1226	},
1227};
1228
1229module_platform_driver(xcan_driver);
1230
1231MODULE_LICENSE("GPL");
1232MODULE_AUTHOR("Xilinx Inc");
1233MODULE_DESCRIPTION("Xilinx CAN interface");