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   1/*
   2 * CAN bus driver for Microchip 251x CAN Controller with SPI Interface
   3 *
   4 * MCP2510 support and bug fixes by Christian Pellegrin
   5 * <chripell@evolware.org>
   6 *
   7 * Copyright 2009 Christian Pellegrin EVOL S.r.l.
   8 *
   9 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.
  10 * Written under contract by:
  11 *   Chris Elston, Katalix Systems, Ltd.
  12 *
  13 * Based on Microchip MCP251x CAN controller driver written by
  14 * David Vrabel, Copyright 2006 Arcom Control Systems Ltd.
  15 *
  16 * Based on CAN bus driver for the CCAN controller written by
  17 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix
  18 * - Simon Kallweit, intefo AG
  19 * Copyright 2007
  20 *
  21 * This program is free software; you can redistribute it and/or modify
  22 * it under the terms of the version 2 of the GNU General Public License
  23 * as published by the Free Software Foundation
  24 *
  25 * This program is distributed in the hope that it will be useful,
  26 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  28 * GNU General Public License for more details.
  29 *
  30 * You should have received a copy of the GNU General Public License
  31 * along with this program; if not, see <http://www.gnu.org/licenses/>.
  32 *
  33 *
  34 *
  35 * Your platform definition file should specify something like:
  36 *
  37 * static struct mcp251x_platform_data mcp251x_info = {
  38 *         .oscillator_frequency = 8000000,
  39 * };
  40 *
  41 * static struct spi_board_info spi_board_info[] = {
  42 *         {
  43 *                 .modalias = "mcp2510",
  44 *			// or "mcp2515" depending on your controller
  45 *                 .platform_data = &mcp251x_info,
  46 *                 .irq = IRQ_EINT13,
  47 *                 .max_speed_hz = 2*1000*1000,
  48 *                 .chip_select = 2,
  49 *         },
  50 * };
  51 *
  52 * Please see mcp251x.h for a description of the fields in
  53 * struct mcp251x_platform_data.
  54 *
  55 */
  56
  57#include <linux/can/core.h>
  58#include <linux/can/dev.h>
  59#include <linux/can/led.h>
  60#include <linux/can/platform/mcp251x.h>
  61#include <linux/clk.h>
  62#include <linux/completion.h>
  63#include <linux/delay.h>
  64#include <linux/device.h>
  65#include <linux/dma-mapping.h>
  66#include <linux/freezer.h>
  67#include <linux/interrupt.h>
  68#include <linux/io.h>
  69#include <linux/kernel.h>
  70#include <linux/module.h>
  71#include <linux/netdevice.h>
  72#include <linux/of.h>
  73#include <linux/of_device.h>
  74#include <linux/platform_device.h>
  75#include <linux/slab.h>
  76#include <linux/spi/spi.h>
  77#include <linux/uaccess.h>
  78#include <linux/regulator/consumer.h>
  79
  80/* SPI interface instruction set */
  81#define INSTRUCTION_WRITE	0x02
  82#define INSTRUCTION_READ	0x03
  83#define INSTRUCTION_BIT_MODIFY	0x05
  84#define INSTRUCTION_LOAD_TXB(n)	(0x40 + 2 * (n))
  85#define INSTRUCTION_READ_RXB(n)	(((n) == 0) ? 0x90 : 0x94)
  86#define INSTRUCTION_RESET	0xC0
  87#define RTS_TXB0		0x01
  88#define RTS_TXB1		0x02
  89#define RTS_TXB2		0x04
  90#define INSTRUCTION_RTS(n)	(0x80 | ((n) & 0x07))
  91
  92
  93/* MPC251x registers */
  94#define CANSTAT	      0x0e
  95#define CANCTRL	      0x0f
  96#  define CANCTRL_REQOP_MASK	    0xe0
  97#  define CANCTRL_REQOP_CONF	    0x80
  98#  define CANCTRL_REQOP_LISTEN_ONLY 0x60
  99#  define CANCTRL_REQOP_LOOPBACK    0x40
 100#  define CANCTRL_REQOP_SLEEP	    0x20
 101#  define CANCTRL_REQOP_NORMAL	    0x00
 102#  define CANCTRL_OSM		    0x08
 103#  define CANCTRL_ABAT		    0x10
 104#define TEC	      0x1c
 105#define REC	      0x1d
 106#define CNF1	      0x2a
 107#  define CNF1_SJW_SHIFT   6
 108#define CNF2	      0x29
 109#  define CNF2_BTLMODE	   0x80
 110#  define CNF2_SAM         0x40
 111#  define CNF2_PS1_SHIFT   3
 112#define CNF3	      0x28
 113#  define CNF3_SOF	   0x08
 114#  define CNF3_WAKFIL	   0x04
 115#  define CNF3_PHSEG2_MASK 0x07
 116#define CANINTE	      0x2b
 117#  define CANINTE_MERRE 0x80
 118#  define CANINTE_WAKIE 0x40
 119#  define CANINTE_ERRIE 0x20
 120#  define CANINTE_TX2IE 0x10
 121#  define CANINTE_TX1IE 0x08
 122#  define CANINTE_TX0IE 0x04
 123#  define CANINTE_RX1IE 0x02
 124#  define CANINTE_RX0IE 0x01
 125#define CANINTF	      0x2c
 126#  define CANINTF_MERRF 0x80
 127#  define CANINTF_WAKIF 0x40
 128#  define CANINTF_ERRIF 0x20
 129#  define CANINTF_TX2IF 0x10
 130#  define CANINTF_TX1IF 0x08
 131#  define CANINTF_TX0IF 0x04
 132#  define CANINTF_RX1IF 0x02
 133#  define CANINTF_RX0IF 0x01
 134#  define CANINTF_RX (CANINTF_RX0IF | CANINTF_RX1IF)
 135#  define CANINTF_TX (CANINTF_TX2IF | CANINTF_TX1IF | CANINTF_TX0IF)
 136#  define CANINTF_ERR (CANINTF_ERRIF)
 137#define EFLG	      0x2d
 138#  define EFLG_EWARN	0x01
 139#  define EFLG_RXWAR	0x02
 140#  define EFLG_TXWAR	0x04
 141#  define EFLG_RXEP	0x08
 142#  define EFLG_TXEP	0x10
 143#  define EFLG_TXBO	0x20
 144#  define EFLG_RX0OVR	0x40
 145#  define EFLG_RX1OVR	0x80
 146#define TXBCTRL(n)  (((n) * 0x10) + 0x30 + TXBCTRL_OFF)
 147#  define TXBCTRL_ABTF	0x40
 148#  define TXBCTRL_MLOA	0x20
 149#  define TXBCTRL_TXERR 0x10
 150#  define TXBCTRL_TXREQ 0x08
 151#define TXBSIDH(n)  (((n) * 0x10) + 0x30 + TXBSIDH_OFF)
 152#  define SIDH_SHIFT    3
 153#define TXBSIDL(n)  (((n) * 0x10) + 0x30 + TXBSIDL_OFF)
 154#  define SIDL_SID_MASK    7
 155#  define SIDL_SID_SHIFT   5
 156#  define SIDL_EXIDE_SHIFT 3
 157#  define SIDL_EID_SHIFT   16
 158#  define SIDL_EID_MASK    3
 159#define TXBEID8(n)  (((n) * 0x10) + 0x30 + TXBEID8_OFF)
 160#define TXBEID0(n)  (((n) * 0x10) + 0x30 + TXBEID0_OFF)
 161#define TXBDLC(n)   (((n) * 0x10) + 0x30 + TXBDLC_OFF)
 162#  define DLC_RTR_SHIFT    6
 163#define TXBCTRL_OFF 0
 164#define TXBSIDH_OFF 1
 165#define TXBSIDL_OFF 2
 166#define TXBEID8_OFF 3
 167#define TXBEID0_OFF 4
 168#define TXBDLC_OFF  5
 169#define TXBDAT_OFF  6
 170#define RXBCTRL(n)  (((n) * 0x10) + 0x60 + RXBCTRL_OFF)
 171#  define RXBCTRL_BUKT	0x04
 172#  define RXBCTRL_RXM0	0x20
 173#  define RXBCTRL_RXM1	0x40
 174#define RXBSIDH(n)  (((n) * 0x10) + 0x60 + RXBSIDH_OFF)
 175#  define RXBSIDH_SHIFT 3
 176#define RXBSIDL(n)  (((n) * 0x10) + 0x60 + RXBSIDL_OFF)
 177#  define RXBSIDL_IDE   0x08
 178#  define RXBSIDL_SRR   0x10
 179#  define RXBSIDL_EID   3
 180#  define RXBSIDL_SHIFT 5
 181#define RXBEID8(n)  (((n) * 0x10) + 0x60 + RXBEID8_OFF)
 182#define RXBEID0(n)  (((n) * 0x10) + 0x60 + RXBEID0_OFF)
 183#define RXBDLC(n)   (((n) * 0x10) + 0x60 + RXBDLC_OFF)
 184#  define RXBDLC_LEN_MASK  0x0f
 185#  define RXBDLC_RTR       0x40
 186#define RXBCTRL_OFF 0
 187#define RXBSIDH_OFF 1
 188#define RXBSIDL_OFF 2
 189#define RXBEID8_OFF 3
 190#define RXBEID0_OFF 4
 191#define RXBDLC_OFF  5
 192#define RXBDAT_OFF  6
 193#define RXFSIDH(n) ((n) * 4)
 194#define RXFSIDL(n) ((n) * 4 + 1)
 195#define RXFEID8(n) ((n) * 4 + 2)
 196#define RXFEID0(n) ((n) * 4 + 3)
 197#define RXMSIDH(n) ((n) * 4 + 0x20)
 198#define RXMSIDL(n) ((n) * 4 + 0x21)
 199#define RXMEID8(n) ((n) * 4 + 0x22)
 200#define RXMEID0(n) ((n) * 4 + 0x23)
 201
 202#define GET_BYTE(val, byte)			\
 203	(((val) >> ((byte) * 8)) & 0xff)
 204#define SET_BYTE(val, byte)			\
 205	(((val) & 0xff) << ((byte) * 8))
 206
 207/*
 208 * Buffer size required for the largest SPI transfer (i.e., reading a
 209 * frame)
 210 */
 211#define CAN_FRAME_MAX_DATA_LEN	8
 212#define SPI_TRANSFER_BUF_LEN	(6 + CAN_FRAME_MAX_DATA_LEN)
 213#define CAN_FRAME_MAX_BITS	128
 214
 215#define TX_ECHO_SKB_MAX	1
 216
 217#define DEVICE_NAME "mcp251x"
 218
 219static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
 220module_param(mcp251x_enable_dma, int, S_IRUGO);
 221MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
 222
 223static const struct can_bittiming_const mcp251x_bittiming_const = {
 224	.name = DEVICE_NAME,
 225	.tseg1_min = 3,
 226	.tseg1_max = 16,
 227	.tseg2_min = 2,
 228	.tseg2_max = 8,
 229	.sjw_max = 4,
 230	.brp_min = 1,
 231	.brp_max = 64,
 232	.brp_inc = 1,
 233};
 234
 235enum mcp251x_model {
 236	CAN_MCP251X_MCP2510	= 0x2510,
 237	CAN_MCP251X_MCP2515	= 0x2515,
 238};
 239
 240struct mcp251x_priv {
 241	struct can_priv	   can;
 242	struct net_device *net;
 243	struct spi_device *spi;
 244	enum mcp251x_model model;
 245
 246	struct mutex mcp_lock; /* SPI device lock */
 247
 248	u8 *spi_tx_buf;
 249	u8 *spi_rx_buf;
 250	dma_addr_t spi_tx_dma;
 251	dma_addr_t spi_rx_dma;
 252
 253	struct sk_buff *tx_skb;
 254	int tx_len;
 255
 256	struct workqueue_struct *wq;
 257	struct work_struct tx_work;
 258	struct work_struct restart_work;
 259
 260	int force_quit;
 261	int after_suspend;
 262#define AFTER_SUSPEND_UP 1
 263#define AFTER_SUSPEND_DOWN 2
 264#define AFTER_SUSPEND_POWER 4
 265#define AFTER_SUSPEND_RESTART 8
 266	int restart_tx;
 267	struct regulator *power;
 268	struct regulator *transceiver;
 269	struct clk *clk;
 270};
 271
 272#define MCP251X_IS(_model) \
 273static inline int mcp251x_is_##_model(struct spi_device *spi) \
 274{ \
 275	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
 276	return priv->model == CAN_MCP251X_MCP##_model; \
 277}
 278
 279MCP251X_IS(2510);
 280MCP251X_IS(2515);
 281
 282static void mcp251x_clean(struct net_device *net)
 283{
 284	struct mcp251x_priv *priv = netdev_priv(net);
 285
 286	if (priv->tx_skb || priv->tx_len)
 287		net->stats.tx_errors++;
 288	if (priv->tx_skb)
 289		dev_kfree_skb(priv->tx_skb);
 290	if (priv->tx_len)
 291		can_free_echo_skb(priv->net, 0);
 292	priv->tx_skb = NULL;
 293	priv->tx_len = 0;
 294}
 295
 296/*
 297 * Note about handling of error return of mcp251x_spi_trans: accessing
 298 * registers via SPI is not really different conceptually than using
 299 * normal I/O assembler instructions, although it's much more
 300 * complicated from a practical POV. So it's not advisable to always
 301 * check the return value of this function. Imagine that every
 302 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
 303 * error();", it would be a great mess (well there are some situation
 304 * when exception handling C++ like could be useful after all). So we
 305 * just check that transfers are OK at the beginning of our
 306 * conversation with the chip and to avoid doing really nasty things
 307 * (like injecting bogus packets in the network stack).
 308 */
 309static int mcp251x_spi_trans(struct spi_device *spi, int len)
 310{
 311	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 312	struct spi_transfer t = {
 313		.tx_buf = priv->spi_tx_buf,
 314		.rx_buf = priv->spi_rx_buf,
 315		.len = len,
 316		.cs_change = 0,
 317	};
 318	struct spi_message m;
 319	int ret;
 320
 321	spi_message_init(&m);
 322
 323	if (mcp251x_enable_dma) {
 324		t.tx_dma = priv->spi_tx_dma;
 325		t.rx_dma = priv->spi_rx_dma;
 326		m.is_dma_mapped = 1;
 327	}
 328
 329	spi_message_add_tail(&t, &m);
 330
 331	ret = spi_sync(spi, &m);
 332	if (ret)
 333		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
 334	return ret;
 335}
 336
 337static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
 338{
 339	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 340	u8 val = 0;
 341
 342	priv->spi_tx_buf[0] = INSTRUCTION_READ;
 343	priv->spi_tx_buf[1] = reg;
 344
 345	mcp251x_spi_trans(spi, 3);
 346	val = priv->spi_rx_buf[2];
 347
 348	return val;
 349}
 350
 351static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
 352		uint8_t *v1, uint8_t *v2)
 353{
 354	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 355
 356	priv->spi_tx_buf[0] = INSTRUCTION_READ;
 357	priv->spi_tx_buf[1] = reg;
 358
 359	mcp251x_spi_trans(spi, 4);
 360
 361	*v1 = priv->spi_rx_buf[2];
 362	*v2 = priv->spi_rx_buf[3];
 363}
 364
 365static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
 366{
 367	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 368
 369	priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
 370	priv->spi_tx_buf[1] = reg;
 371	priv->spi_tx_buf[2] = val;
 372
 373	mcp251x_spi_trans(spi, 3);
 374}
 375
 376static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
 377			       u8 mask, uint8_t val)
 378{
 379	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 380
 381	priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
 382	priv->spi_tx_buf[1] = reg;
 383	priv->spi_tx_buf[2] = mask;
 384	priv->spi_tx_buf[3] = val;
 385
 386	mcp251x_spi_trans(spi, 4);
 387}
 388
 389static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
 390				int len, int tx_buf_idx)
 391{
 392	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 393
 394	if (mcp251x_is_2510(spi)) {
 395		int i;
 396
 397		for (i = 1; i < TXBDAT_OFF + len; i++)
 398			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
 399					  buf[i]);
 400	} else {
 401		memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
 402		mcp251x_spi_trans(spi, TXBDAT_OFF + len);
 403	}
 404}
 405
 406static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
 407			  int tx_buf_idx)
 408{
 409	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 410	u32 sid, eid, exide, rtr;
 411	u8 buf[SPI_TRANSFER_BUF_LEN];
 412
 413	exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
 414	if (exide)
 415		sid = (frame->can_id & CAN_EFF_MASK) >> 18;
 416	else
 417		sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
 418	eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
 419	rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
 420
 421	buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
 422	buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
 423	buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
 424		(exide << SIDL_EXIDE_SHIFT) |
 425		((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
 426	buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
 427	buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
 428	buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
 429	memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
 430	mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
 431
 432	/* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
 433	priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
 434	mcp251x_spi_trans(priv->spi, 1);
 435}
 436
 437static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
 438				int buf_idx)
 439{
 440	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 441
 442	if (mcp251x_is_2510(spi)) {
 443		int i, len;
 444
 445		for (i = 1; i < RXBDAT_OFF; i++)
 446			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 447
 448		len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 449		for (; i < (RXBDAT_OFF + len); i++)
 450			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 451	} else {
 452		priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
 453		mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
 454		memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
 455	}
 456}
 457
 458static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 459{
 460	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 461	struct sk_buff *skb;
 462	struct can_frame *frame;
 463	u8 buf[SPI_TRANSFER_BUF_LEN];
 464
 465	skb = alloc_can_skb(priv->net, &frame);
 466	if (!skb) {
 467		dev_err(&spi->dev, "cannot allocate RX skb\n");
 468		priv->net->stats.rx_dropped++;
 469		return;
 470	}
 471
 472	mcp251x_hw_rx_frame(spi, buf, buf_idx);
 473	if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
 474		/* Extended ID format */
 475		frame->can_id = CAN_EFF_FLAG;
 476		frame->can_id |=
 477			/* Extended ID part */
 478			SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
 479			SET_BYTE(buf[RXBEID8_OFF], 1) |
 480			SET_BYTE(buf[RXBEID0_OFF], 0) |
 481			/* Standard ID part */
 482			(((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 483			  (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
 484		/* Remote transmission request */
 485		if (buf[RXBDLC_OFF] & RXBDLC_RTR)
 486			frame->can_id |= CAN_RTR_FLAG;
 487	} else {
 488		/* Standard ID format */
 489		frame->can_id =
 490			(buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 491			(buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
 492		if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
 493			frame->can_id |= CAN_RTR_FLAG;
 494	}
 495	/* Data length */
 496	frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 497	memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
 498
 499	priv->net->stats.rx_packets++;
 500	priv->net->stats.rx_bytes += frame->can_dlc;
 501
 502	can_led_event(priv->net, CAN_LED_EVENT_RX);
 503
 504	netif_rx_ni(skb);
 505}
 506
 507static void mcp251x_hw_sleep(struct spi_device *spi)
 508{
 509	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
 510}
 511
 512static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
 513					   struct net_device *net)
 514{
 515	struct mcp251x_priv *priv = netdev_priv(net);
 516	struct spi_device *spi = priv->spi;
 517
 518	if (priv->tx_skb || priv->tx_len) {
 519		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
 520		return NETDEV_TX_BUSY;
 521	}
 522
 523	if (can_dropped_invalid_skb(net, skb))
 524		return NETDEV_TX_OK;
 525
 526	netif_stop_queue(net);
 527	priv->tx_skb = skb;
 528	queue_work(priv->wq, &priv->tx_work);
 529
 530	return NETDEV_TX_OK;
 531}
 532
 533static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
 534{
 535	struct mcp251x_priv *priv = netdev_priv(net);
 536
 537	switch (mode) {
 538	case CAN_MODE_START:
 539		mcp251x_clean(net);
 540		/* We have to delay work since SPI I/O may sleep */
 541		priv->can.state = CAN_STATE_ERROR_ACTIVE;
 542		priv->restart_tx = 1;
 543		if (priv->can.restart_ms == 0)
 544			priv->after_suspend = AFTER_SUSPEND_RESTART;
 545		queue_work(priv->wq, &priv->restart_work);
 546		break;
 547	default:
 548		return -EOPNOTSUPP;
 549	}
 550
 551	return 0;
 552}
 553
 554static int mcp251x_set_normal_mode(struct spi_device *spi)
 555{
 556	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 557	unsigned long timeout;
 558
 559	/* Enable interrupts */
 560	mcp251x_write_reg(spi, CANINTE,
 561			  CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
 562			  CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
 563
 564	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 565		/* Put device into loopback mode */
 566		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
 567	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 568		/* Put device into listen-only mode */
 569		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
 570	} else {
 571		/* Put device into normal mode */
 572		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
 573
 574		/* Wait for the device to enter normal mode */
 575		timeout = jiffies + HZ;
 576		while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
 577			schedule();
 578			if (time_after(jiffies, timeout)) {
 579				dev_err(&spi->dev, "MCP251x didn't"
 580					" enter in normal mode\n");
 581				return -EBUSY;
 582			}
 583		}
 584	}
 585	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 586	return 0;
 587}
 588
 589static int mcp251x_do_set_bittiming(struct net_device *net)
 590{
 591	struct mcp251x_priv *priv = netdev_priv(net);
 592	struct can_bittiming *bt = &priv->can.bittiming;
 593	struct spi_device *spi = priv->spi;
 594
 595	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
 596			  (bt->brp - 1));
 597	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
 598			  (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
 599			   CNF2_SAM : 0) |
 600			  ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
 601			  (bt->prop_seg - 1));
 602	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
 603			   (bt->phase_seg2 - 1));
 604	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
 605		mcp251x_read_reg(spi, CNF1),
 606		mcp251x_read_reg(spi, CNF2),
 607		mcp251x_read_reg(spi, CNF3));
 608
 609	return 0;
 610}
 611
 612static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
 613			 struct spi_device *spi)
 614{
 615	mcp251x_do_set_bittiming(net);
 616
 617	mcp251x_write_reg(spi, RXBCTRL(0),
 618			  RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
 619	mcp251x_write_reg(spi, RXBCTRL(1),
 620			  RXBCTRL_RXM0 | RXBCTRL_RXM1);
 621	return 0;
 622}
 623
 624static int mcp251x_hw_reset(struct spi_device *spi)
 625{
 626	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 627	int ret;
 628	unsigned long timeout;
 629
 630	priv->spi_tx_buf[0] = INSTRUCTION_RESET;
 631	ret = spi_write(spi, priv->spi_tx_buf, 1);
 632	if (ret) {
 633		dev_err(&spi->dev, "reset failed: ret = %d\n", ret);
 634		return -EIO;
 635	}
 636
 637	/* Wait for reset to finish */
 638	timeout = jiffies + HZ;
 639	mdelay(10);
 640	while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK)
 641	       != CANCTRL_REQOP_CONF) {
 642		schedule();
 643		if (time_after(jiffies, timeout)) {
 644			dev_err(&spi->dev, "MCP251x didn't"
 645				" enter in conf mode after reset\n");
 646			return -EBUSY;
 647		}
 648	}
 649	return 0;
 650}
 651
 652static int mcp251x_hw_probe(struct spi_device *spi)
 653{
 654	int st1, st2;
 655
 656	mcp251x_hw_reset(spi);
 657
 658	/*
 659	 * Please note that these are "magic values" based on after
 660	 * reset defaults taken from data sheet which allows us to see
 661	 * if we really have a chip on the bus (we avoid common all
 662	 * zeroes or all ones situations)
 663	 */
 664	st1 = mcp251x_read_reg(spi, CANSTAT) & 0xEE;
 665	st2 = mcp251x_read_reg(spi, CANCTRL) & 0x17;
 666
 667	dev_dbg(&spi->dev, "CANSTAT 0x%02x CANCTRL 0x%02x\n", st1, st2);
 668
 669	/* Check for power up default values */
 670	return (st1 == 0x80 && st2 == 0x07) ? 1 : 0;
 671}
 672
 673static int mcp251x_power_enable(struct regulator *reg, int enable)
 674{
 675	if (IS_ERR_OR_NULL(reg))
 676		return 0;
 677
 678	if (enable)
 679		return regulator_enable(reg);
 680	else
 681		return regulator_disable(reg);
 682}
 683
 684static void mcp251x_open_clean(struct net_device *net)
 685{
 686	struct mcp251x_priv *priv = netdev_priv(net);
 687	struct spi_device *spi = priv->spi;
 688
 689	free_irq(spi->irq, priv);
 690	mcp251x_hw_sleep(spi);
 691	mcp251x_power_enable(priv->transceiver, 0);
 692	close_candev(net);
 693}
 694
 695static int mcp251x_stop(struct net_device *net)
 696{
 697	struct mcp251x_priv *priv = netdev_priv(net);
 698	struct spi_device *spi = priv->spi;
 699
 700	close_candev(net);
 701
 702	priv->force_quit = 1;
 703	free_irq(spi->irq, priv);
 704	destroy_workqueue(priv->wq);
 705	priv->wq = NULL;
 706
 707	mutex_lock(&priv->mcp_lock);
 708
 709	/* Disable and clear pending interrupts */
 710	mcp251x_write_reg(spi, CANINTE, 0x00);
 711	mcp251x_write_reg(spi, CANINTF, 0x00);
 712
 713	mcp251x_write_reg(spi, TXBCTRL(0), 0);
 714	mcp251x_clean(net);
 715
 716	mcp251x_hw_sleep(spi);
 717
 718	mcp251x_power_enable(priv->transceiver, 0);
 719
 720	priv->can.state = CAN_STATE_STOPPED;
 721
 722	mutex_unlock(&priv->mcp_lock);
 723
 724	can_led_event(net, CAN_LED_EVENT_STOP);
 725
 726	return 0;
 727}
 728
 729static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
 730{
 731	struct sk_buff *skb;
 732	struct can_frame *frame;
 733
 734	skb = alloc_can_err_skb(net, &frame);
 735	if (skb) {
 736		frame->can_id |= can_id;
 737		frame->data[1] = data1;
 738		netif_rx_ni(skb);
 739	} else {
 740		netdev_err(net, "cannot allocate error skb\n");
 741	}
 742}
 743
 744static void mcp251x_tx_work_handler(struct work_struct *ws)
 745{
 746	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
 747						 tx_work);
 748	struct spi_device *spi = priv->spi;
 749	struct net_device *net = priv->net;
 750	struct can_frame *frame;
 751
 752	mutex_lock(&priv->mcp_lock);
 753	if (priv->tx_skb) {
 754		if (priv->can.state == CAN_STATE_BUS_OFF) {
 755			mcp251x_clean(net);
 756		} else {
 757			frame = (struct can_frame *)priv->tx_skb->data;
 758
 759			if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
 760				frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
 761			mcp251x_hw_tx(spi, frame, 0);
 762			priv->tx_len = 1 + frame->can_dlc;
 763			can_put_echo_skb(priv->tx_skb, net, 0);
 764			priv->tx_skb = NULL;
 765		}
 766	}
 767	mutex_unlock(&priv->mcp_lock);
 768}
 769
 770static void mcp251x_restart_work_handler(struct work_struct *ws)
 771{
 772	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
 773						 restart_work);
 774	struct spi_device *spi = priv->spi;
 775	struct net_device *net = priv->net;
 776
 777	mutex_lock(&priv->mcp_lock);
 778	if (priv->after_suspend) {
 779		mdelay(10);
 780		mcp251x_hw_reset(spi);
 781		mcp251x_setup(net, priv, spi);
 782		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
 783			mcp251x_set_normal_mode(spi);
 784		} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
 785			netif_device_attach(net);
 786			mcp251x_clean(net);
 787			mcp251x_set_normal_mode(spi);
 788			netif_wake_queue(net);
 789		} else {
 790			mcp251x_hw_sleep(spi);
 791		}
 792		priv->after_suspend = 0;
 793		priv->force_quit = 0;
 794	}
 795
 796	if (priv->restart_tx) {
 797		priv->restart_tx = 0;
 798		mcp251x_write_reg(spi, TXBCTRL(0), 0);
 799		mcp251x_clean(net);
 800		netif_wake_queue(net);
 801		mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
 802	}
 803	mutex_unlock(&priv->mcp_lock);
 804}
 805
 806static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
 807{
 808	struct mcp251x_priv *priv = dev_id;
 809	struct spi_device *spi = priv->spi;
 810	struct net_device *net = priv->net;
 811
 812	mutex_lock(&priv->mcp_lock);
 813	while (!priv->force_quit) {
 814		enum can_state new_state;
 815		u8 intf, eflag;
 816		u8 clear_intf = 0;
 817		int can_id = 0, data1 = 0;
 818
 819		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
 820
 821		/* mask out flags we don't care about */
 822		intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
 823
 824		/* receive buffer 0 */
 825		if (intf & CANINTF_RX0IF) {
 826			mcp251x_hw_rx(spi, 0);
 827			/*
 828			 * Free one buffer ASAP
 829			 * (The MCP2515 does this automatically.)
 830			 */
 831			if (mcp251x_is_2510(spi))
 832				mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
 833		}
 834
 835		/* receive buffer 1 */
 836		if (intf & CANINTF_RX1IF) {
 837			mcp251x_hw_rx(spi, 1);
 838			/* the MCP2515 does this automatically */
 839			if (mcp251x_is_2510(spi))
 840				clear_intf |= CANINTF_RX1IF;
 841		}
 842
 843		/* any error or tx interrupt we need to clear? */
 844		if (intf & (CANINTF_ERR | CANINTF_TX))
 845			clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
 846		if (clear_intf)
 847			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
 848
 849		if (eflag)
 850			mcp251x_write_bits(spi, EFLG, eflag, 0x00);
 851
 852		/* Update can state */
 853		if (eflag & EFLG_TXBO) {
 854			new_state = CAN_STATE_BUS_OFF;
 855			can_id |= CAN_ERR_BUSOFF;
 856		} else if (eflag & EFLG_TXEP) {
 857			new_state = CAN_STATE_ERROR_PASSIVE;
 858			can_id |= CAN_ERR_CRTL;
 859			data1 |= CAN_ERR_CRTL_TX_PASSIVE;
 860		} else if (eflag & EFLG_RXEP) {
 861			new_state = CAN_STATE_ERROR_PASSIVE;
 862			can_id |= CAN_ERR_CRTL;
 863			data1 |= CAN_ERR_CRTL_RX_PASSIVE;
 864		} else if (eflag & EFLG_TXWAR) {
 865			new_state = CAN_STATE_ERROR_WARNING;
 866			can_id |= CAN_ERR_CRTL;
 867			data1 |= CAN_ERR_CRTL_TX_WARNING;
 868		} else if (eflag & EFLG_RXWAR) {
 869			new_state = CAN_STATE_ERROR_WARNING;
 870			can_id |= CAN_ERR_CRTL;
 871			data1 |= CAN_ERR_CRTL_RX_WARNING;
 872		} else {
 873			new_state = CAN_STATE_ERROR_ACTIVE;
 874		}
 875
 876		/* Update can state statistics */
 877		switch (priv->can.state) {
 878		case CAN_STATE_ERROR_ACTIVE:
 879			if (new_state >= CAN_STATE_ERROR_WARNING &&
 880			    new_state <= CAN_STATE_BUS_OFF)
 881				priv->can.can_stats.error_warning++;
 882		case CAN_STATE_ERROR_WARNING:	/* fallthrough */
 883			if (new_state >= CAN_STATE_ERROR_PASSIVE &&
 884			    new_state <= CAN_STATE_BUS_OFF)
 885				priv->can.can_stats.error_passive++;
 886			break;
 887		default:
 888			break;
 889		}
 890		priv->can.state = new_state;
 891
 892		if (intf & CANINTF_ERRIF) {
 893			/* Handle overflow counters */
 894			if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
 895				if (eflag & EFLG_RX0OVR) {
 896					net->stats.rx_over_errors++;
 897					net->stats.rx_errors++;
 898				}
 899				if (eflag & EFLG_RX1OVR) {
 900					net->stats.rx_over_errors++;
 901					net->stats.rx_errors++;
 902				}
 903				can_id |= CAN_ERR_CRTL;
 904				data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
 905			}
 906			mcp251x_error_skb(net, can_id, data1);
 907		}
 908
 909		if (priv->can.state == CAN_STATE_BUS_OFF) {
 910			if (priv->can.restart_ms == 0) {
 911				priv->force_quit = 1;
 912				can_bus_off(net);
 913				mcp251x_hw_sleep(spi);
 914				break;
 915			}
 916		}
 917
 918		if (intf == 0)
 919			break;
 920
 921		if (intf & CANINTF_TX) {
 922			net->stats.tx_packets++;
 923			net->stats.tx_bytes += priv->tx_len - 1;
 924			can_led_event(net, CAN_LED_EVENT_TX);
 925			if (priv->tx_len) {
 926				can_get_echo_skb(net, 0);
 927				priv->tx_len = 0;
 928			}
 929			netif_wake_queue(net);
 930		}
 931
 932	}
 933	mutex_unlock(&priv->mcp_lock);
 934	return IRQ_HANDLED;
 935}
 936
 937static int mcp251x_open(struct net_device *net)
 938{
 939	struct mcp251x_priv *priv = netdev_priv(net);
 940	struct spi_device *spi = priv->spi;
 941	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
 942	int ret;
 943
 944	ret = open_candev(net);
 945	if (ret) {
 946		dev_err(&spi->dev, "unable to set initial baudrate!\n");
 947		return ret;
 948	}
 949
 950	mutex_lock(&priv->mcp_lock);
 951	mcp251x_power_enable(priv->transceiver, 1);
 952
 953	priv->force_quit = 0;
 954	priv->tx_skb = NULL;
 955	priv->tx_len = 0;
 956
 957	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
 958				   flags, DEVICE_NAME, priv);
 959	if (ret) {
 960		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
 961		mcp251x_power_enable(priv->transceiver, 0);
 962		close_candev(net);
 963		goto open_unlock;
 964	}
 965
 966	priv->wq = create_freezable_workqueue("mcp251x_wq");
 967	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
 968	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
 969
 970	ret = mcp251x_hw_reset(spi);
 971	if (ret) {
 972		mcp251x_open_clean(net);
 973		goto open_unlock;
 974	}
 975	ret = mcp251x_setup(net, priv, spi);
 976	if (ret) {
 977		mcp251x_open_clean(net);
 978		goto open_unlock;
 979	}
 980	ret = mcp251x_set_normal_mode(spi);
 981	if (ret) {
 982		mcp251x_open_clean(net);
 983		goto open_unlock;
 984	}
 985
 986	can_led_event(net, CAN_LED_EVENT_OPEN);
 987
 988	netif_wake_queue(net);
 989
 990open_unlock:
 991	mutex_unlock(&priv->mcp_lock);
 992	return ret;
 993}
 994
 995static const struct net_device_ops mcp251x_netdev_ops = {
 996	.ndo_open = mcp251x_open,
 997	.ndo_stop = mcp251x_stop,
 998	.ndo_start_xmit = mcp251x_hard_start_xmit,
 999	.ndo_change_mtu = can_change_mtu,
1000};
1001
1002static const struct of_device_id mcp251x_of_match[] = {
1003	{
1004		.compatible	= "microchip,mcp2510",
1005		.data		= (void *)CAN_MCP251X_MCP2510,
1006	},
1007	{
1008		.compatible	= "microchip,mcp2515",
1009		.data		= (void *)CAN_MCP251X_MCP2515,
1010	},
1011	{ }
1012};
1013MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1014
1015static const struct spi_device_id mcp251x_id_table[] = {
1016	{
1017		.name		= "mcp2510",
1018		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2510,
1019	},
1020	{
1021		.name		= "mcp2515",
1022		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2515,
1023	},
1024	{ }
1025};
1026MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1027
1028static int mcp251x_can_probe(struct spi_device *spi)
1029{
1030	const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
1031							   &spi->dev);
1032	struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
1033	struct net_device *net;
1034	struct mcp251x_priv *priv;
1035	int freq, ret = -ENODEV;
1036	struct clk *clk;
1037
1038	clk = devm_clk_get(&spi->dev, NULL);
1039	if (IS_ERR(clk)) {
1040		if (pdata)
1041			freq = pdata->oscillator_frequency;
1042		else
1043			return PTR_ERR(clk);
1044	} else {
1045		freq = clk_get_rate(clk);
1046	}
1047
1048	/* Sanity check */
1049	if (freq < 1000000 || freq > 25000000)
1050		return -ERANGE;
1051
1052	/* Allocate can/net device */
1053	net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1054	if (!net)
1055		return -ENOMEM;
1056
1057	if (!IS_ERR(clk)) {
1058		ret = clk_prepare_enable(clk);
1059		if (ret)
1060			goto out_free;
1061	}
1062
1063	net->netdev_ops = &mcp251x_netdev_ops;
1064	net->flags |= IFF_ECHO;
1065
1066	priv = netdev_priv(net);
1067	priv->can.bittiming_const = &mcp251x_bittiming_const;
1068	priv->can.do_set_mode = mcp251x_do_set_mode;
1069	priv->can.clock.freq = freq / 2;
1070	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1071		CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1072	if (of_id)
1073		priv->model = (enum mcp251x_model)of_id->data;
1074	else
1075		priv->model = spi_get_device_id(spi)->driver_data;
1076	priv->net = net;
1077	priv->clk = clk;
1078
1079	priv->power = devm_regulator_get(&spi->dev, "vdd");
1080	priv->transceiver = devm_regulator_get(&spi->dev, "xceiver");
1081	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1082	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1083		ret = -EPROBE_DEFER;
1084		goto out_clk;
1085	}
1086
1087	ret = mcp251x_power_enable(priv->power, 1);
1088	if (ret)
1089		goto out_clk;
1090
1091	spi_set_drvdata(spi, priv);
1092
1093	priv->spi = spi;
1094	mutex_init(&priv->mcp_lock);
1095
1096	/* If requested, allocate DMA buffers */
1097	if (mcp251x_enable_dma) {
1098		spi->dev.coherent_dma_mask = ~0;
1099
1100		/*
1101		 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1102		 * that much and share it between Tx and Rx DMA buffers.
1103		 */
1104		priv->spi_tx_buf = dma_alloc_coherent(&spi->dev,
1105						      PAGE_SIZE,
1106						      &priv->spi_tx_dma,
1107						      GFP_DMA);
1108
1109		if (priv->spi_tx_buf) {
1110			priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
1111			priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
1112							(PAGE_SIZE / 2));
1113		} else {
1114			/* Fall back to non-DMA */
1115			mcp251x_enable_dma = 0;
1116		}
1117	}
1118
1119	/* Allocate non-DMA buffers */
1120	if (!mcp251x_enable_dma) {
1121		priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1122						GFP_KERNEL);
1123		if (!priv->spi_tx_buf) {
1124			ret = -ENOMEM;
1125			goto error_probe;
1126		}
1127		priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1128						GFP_KERNEL);
1129		if (!priv->spi_rx_buf) {
1130			ret = -ENOMEM;
1131			goto error_probe;
1132		}
1133	}
1134
1135	SET_NETDEV_DEV(net, &spi->dev);
1136
1137	/* Configure the SPI bus */
1138	spi->mode = spi->mode ? : SPI_MODE_0;
1139	if (mcp251x_is_2510(spi))
1140		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1141	else
1142		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1143	spi->bits_per_word = 8;
1144	spi_setup(spi);
1145
1146	/* Here is OK to not lock the MCP, no one knows about it yet */
1147	if (!mcp251x_hw_probe(spi)) {
1148		ret = -ENODEV;
1149		goto error_probe;
1150	}
1151	mcp251x_hw_sleep(spi);
1152
1153	ret = register_candev(net);
1154	if (ret)
1155		goto error_probe;
1156
1157	devm_can_led_init(net);
1158
1159	return ret;
1160
1161error_probe:
1162	if (mcp251x_enable_dma)
1163		dma_free_coherent(&spi->dev, PAGE_SIZE,
1164				  priv->spi_tx_buf, priv->spi_tx_dma);
1165	mcp251x_power_enable(priv->power, 0);
1166
1167out_clk:
1168	if (!IS_ERR(clk))
1169		clk_disable_unprepare(clk);
1170
1171out_free:
1172	free_candev(net);
1173
1174	return ret;
1175}
1176
1177static int mcp251x_can_remove(struct spi_device *spi)
1178{
1179	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1180	struct net_device *net = priv->net;
1181
1182	unregister_candev(net);
1183
1184	if (mcp251x_enable_dma) {
1185		dma_free_coherent(&spi->dev, PAGE_SIZE,
1186				  priv->spi_tx_buf, priv->spi_tx_dma);
1187	}
1188
1189	mcp251x_power_enable(priv->power, 0);
1190
1191	if (!IS_ERR(priv->clk))
1192		clk_disable_unprepare(priv->clk);
1193
1194	free_candev(net);
1195
1196	return 0;
1197}
1198
1199static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1200{
1201	struct spi_device *spi = to_spi_device(dev);
1202	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1203	struct net_device *net = priv->net;
1204
1205	priv->force_quit = 1;
1206	disable_irq(spi->irq);
1207	/*
1208	 * Note: at this point neither IST nor workqueues are running.
1209	 * open/stop cannot be called anyway so locking is not needed
1210	 */
1211	if (netif_running(net)) {
1212		netif_device_detach(net);
1213
1214		mcp251x_hw_sleep(spi);
1215		mcp251x_power_enable(priv->transceiver, 0);
1216		priv->after_suspend = AFTER_SUSPEND_UP;
1217	} else {
1218		priv->after_suspend = AFTER_SUSPEND_DOWN;
1219	}
1220
1221	if (!IS_ERR_OR_NULL(priv->power)) {
1222		regulator_disable(priv->power);
1223		priv->after_suspend |= AFTER_SUSPEND_POWER;
1224	}
1225
1226	return 0;
1227}
1228
1229static int __maybe_unused mcp251x_can_resume(struct device *dev)
1230{
1231	struct spi_device *spi = to_spi_device(dev);
1232	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1233
1234	if (priv->after_suspend & AFTER_SUSPEND_POWER) {
1235		mcp251x_power_enable(priv->power, 1);
1236		queue_work(priv->wq, &priv->restart_work);
1237	} else {
1238		if (priv->after_suspend & AFTER_SUSPEND_UP) {
1239			mcp251x_power_enable(priv->transceiver, 1);
1240			queue_work(priv->wq, &priv->restart_work);
1241		} else {
1242			priv->after_suspend = 0;
1243		}
1244	}
1245	priv->force_quit = 0;
1246	enable_irq(spi->irq);
1247	return 0;
1248}
1249
1250static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1251	mcp251x_can_resume);
1252
1253static struct spi_driver mcp251x_can_driver = {
1254	.driver = {
1255		.name = DEVICE_NAME,
1256		.owner = THIS_MODULE,
1257		.of_match_table = mcp251x_of_match,
1258		.pm = &mcp251x_can_pm_ops,
1259	},
1260	.id_table = mcp251x_id_table,
1261	.probe = mcp251x_can_probe,
1262	.remove = mcp251x_can_remove,
1263};
1264module_spi_driver(mcp251x_can_driver);
1265
1266MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1267	      "Christian Pellegrin <chripell@evolware.org>");
1268MODULE_DESCRIPTION("Microchip 251x CAN driver");
1269MODULE_LICENSE("GPL v2");