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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 RXFSID(n) ((n < 3) ? 0 : 4)
 194#define RXFSIDH(n) ((n) * 4 + RXFSID(n))
 195#define RXFSIDL(n) ((n) * 4 + 1 + RXFSID(n))
 196#define RXFEID8(n) ((n) * 4 + 2 + RXFSID(n))
 197#define RXFEID0(n) ((n) * 4 + 3 + RXFSID(n))
 198#define RXMSIDH(n) ((n) * 4 + 0x20)
 199#define RXMSIDL(n) ((n) * 4 + 0x21)
 200#define RXMEID8(n) ((n) * 4 + 0x22)
 201#define RXMEID0(n) ((n) * 4 + 0x23)
 202
 203#define GET_BYTE(val, byte)			\
 204	(((val) >> ((byte) * 8)) & 0xff)
 205#define SET_BYTE(val, byte)			\
 206	(((val) & 0xff) << ((byte) * 8))
 207
 208/*
 209 * Buffer size required for the largest SPI transfer (i.e., reading a
 210 * frame)
 211 */
 212#define CAN_FRAME_MAX_DATA_LEN	8
 213#define SPI_TRANSFER_BUF_LEN	(6 + CAN_FRAME_MAX_DATA_LEN)
 214#define CAN_FRAME_MAX_BITS	128
 215
 216#define TX_ECHO_SKB_MAX	1
 217
 218#define MCP251X_OST_DELAY_MS	(5)
 219
 220#define DEVICE_NAME "mcp251x"
 221
 222static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
 223module_param(mcp251x_enable_dma, int, S_IRUGO);
 224MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
 225
 226static const struct can_bittiming_const mcp251x_bittiming_const = {
 227	.name = DEVICE_NAME,
 228	.tseg1_min = 3,
 229	.tseg1_max = 16,
 230	.tseg2_min = 2,
 231	.tseg2_max = 8,
 232	.sjw_max = 4,
 233	.brp_min = 1,
 234	.brp_max = 64,
 235	.brp_inc = 1,
 236};
 237
 238enum mcp251x_model {
 239	CAN_MCP251X_MCP2510	= 0x2510,
 240	CAN_MCP251X_MCP2515	= 0x2515,
 241};
 242
 243struct mcp251x_priv {
 244	struct can_priv	   can;
 245	struct net_device *net;
 246	struct spi_device *spi;
 247	enum mcp251x_model model;
 248
 249	struct mutex mcp_lock; /* SPI device lock */
 250
 251	u8 *spi_tx_buf;
 252	u8 *spi_rx_buf;
 253	dma_addr_t spi_tx_dma;
 254	dma_addr_t spi_rx_dma;
 255
 256	struct sk_buff *tx_skb;
 257	int tx_len;
 258
 259	struct workqueue_struct *wq;
 260	struct work_struct tx_work;
 261	struct work_struct restart_work;
 262
 263	int force_quit;
 264	int after_suspend;
 265#define AFTER_SUSPEND_UP 1
 266#define AFTER_SUSPEND_DOWN 2
 267#define AFTER_SUSPEND_POWER 4
 268#define AFTER_SUSPEND_RESTART 8
 269	int restart_tx;
 270	struct regulator *power;
 271	struct regulator *transceiver;
 272	struct clk *clk;
 273};
 274
 275#define MCP251X_IS(_model) \
 276static inline int mcp251x_is_##_model(struct spi_device *spi) \
 277{ \
 278	struct mcp251x_priv *priv = spi_get_drvdata(spi); \
 279	return priv->model == CAN_MCP251X_MCP##_model; \
 280}
 281
 282MCP251X_IS(2510);
 283MCP251X_IS(2515);
 284
 285static void mcp251x_clean(struct net_device *net)
 286{
 287	struct mcp251x_priv *priv = netdev_priv(net);
 288
 289	if (priv->tx_skb || priv->tx_len)
 290		net->stats.tx_errors++;
 291	if (priv->tx_skb)
 292		dev_kfree_skb(priv->tx_skb);
 293	if (priv->tx_len)
 294		can_free_echo_skb(priv->net, 0);
 295	priv->tx_skb = NULL;
 296	priv->tx_len = 0;
 297}
 298
 299/*
 300 * Note about handling of error return of mcp251x_spi_trans: accessing
 301 * registers via SPI is not really different conceptually than using
 302 * normal I/O assembler instructions, although it's much more
 303 * complicated from a practical POV. So it's not advisable to always
 304 * check the return value of this function. Imagine that every
 305 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)
 306 * error();", it would be a great mess (well there are some situation
 307 * when exception handling C++ like could be useful after all). So we
 308 * just check that transfers are OK at the beginning of our
 309 * conversation with the chip and to avoid doing really nasty things
 310 * (like injecting bogus packets in the network stack).
 311 */
 312static int mcp251x_spi_trans(struct spi_device *spi, int len)
 313{
 314	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 315	struct spi_transfer t = {
 316		.tx_buf = priv->spi_tx_buf,
 317		.rx_buf = priv->spi_rx_buf,
 318		.len = len,
 319		.cs_change = 0,
 320	};
 321	struct spi_message m;
 322	int ret;
 323
 324	spi_message_init(&m);
 325
 326	if (mcp251x_enable_dma) {
 327		t.tx_dma = priv->spi_tx_dma;
 328		t.rx_dma = priv->spi_rx_dma;
 329		m.is_dma_mapped = 1;
 330	}
 331
 332	spi_message_add_tail(&t, &m);
 333
 334	ret = spi_sync(spi, &m);
 335	if (ret)
 336		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);
 337	return ret;
 338}
 339
 340static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
 341{
 342	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 343	u8 val = 0;
 344
 345	priv->spi_tx_buf[0] = INSTRUCTION_READ;
 346	priv->spi_tx_buf[1] = reg;
 347
 348	mcp251x_spi_trans(spi, 3);
 349	val = priv->spi_rx_buf[2];
 350
 351	return val;
 352}
 353
 354static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
 355		uint8_t *v1, uint8_t *v2)
 356{
 357	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 358
 359	priv->spi_tx_buf[0] = INSTRUCTION_READ;
 360	priv->spi_tx_buf[1] = reg;
 361
 362	mcp251x_spi_trans(spi, 4);
 363
 364	*v1 = priv->spi_rx_buf[2];
 365	*v2 = priv->spi_rx_buf[3];
 366}
 367
 368static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
 369{
 370	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 371
 372	priv->spi_tx_buf[0] = INSTRUCTION_WRITE;
 373	priv->spi_tx_buf[1] = reg;
 374	priv->spi_tx_buf[2] = val;
 375
 376	mcp251x_spi_trans(spi, 3);
 377}
 378
 379static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
 380			       u8 mask, uint8_t val)
 381{
 382	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 383
 384	priv->spi_tx_buf[0] = INSTRUCTION_BIT_MODIFY;
 385	priv->spi_tx_buf[1] = reg;
 386	priv->spi_tx_buf[2] = mask;
 387	priv->spi_tx_buf[3] = val;
 388
 389	mcp251x_spi_trans(spi, 4);
 390}
 391
 392static void mcp251x_hw_tx_frame(struct spi_device *spi, u8 *buf,
 393				int len, int tx_buf_idx)
 394{
 395	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 396
 397	if (mcp251x_is_2510(spi)) {
 398		int i;
 399
 400		for (i = 1; i < TXBDAT_OFF + len; i++)
 401			mcp251x_write_reg(spi, TXBCTRL(tx_buf_idx) + i,
 402					  buf[i]);
 403	} else {
 404		memcpy(priv->spi_tx_buf, buf, TXBDAT_OFF + len);
 405		mcp251x_spi_trans(spi, TXBDAT_OFF + len);
 406	}
 407}
 408
 409static void mcp251x_hw_tx(struct spi_device *spi, struct can_frame *frame,
 410			  int tx_buf_idx)
 411{
 412	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 413	u32 sid, eid, exide, rtr;
 414	u8 buf[SPI_TRANSFER_BUF_LEN];
 415
 416	exide = (frame->can_id & CAN_EFF_FLAG) ? 1 : 0; /* Extended ID Enable */
 417	if (exide)
 418		sid = (frame->can_id & CAN_EFF_MASK) >> 18;
 419	else
 420		sid = frame->can_id & CAN_SFF_MASK; /* Standard ID */
 421	eid = frame->can_id & CAN_EFF_MASK; /* Extended ID */
 422	rtr = (frame->can_id & CAN_RTR_FLAG) ? 1 : 0; /* Remote transmission */
 423
 424	buf[TXBCTRL_OFF] = INSTRUCTION_LOAD_TXB(tx_buf_idx);
 425	buf[TXBSIDH_OFF] = sid >> SIDH_SHIFT;
 426	buf[TXBSIDL_OFF] = ((sid & SIDL_SID_MASK) << SIDL_SID_SHIFT) |
 427		(exide << SIDL_EXIDE_SHIFT) |
 428		((eid >> SIDL_EID_SHIFT) & SIDL_EID_MASK);
 429	buf[TXBEID8_OFF] = GET_BYTE(eid, 1);
 430	buf[TXBEID0_OFF] = GET_BYTE(eid, 0);
 431	buf[TXBDLC_OFF] = (rtr << DLC_RTR_SHIFT) | frame->can_dlc;
 432	memcpy(buf + TXBDAT_OFF, frame->data, frame->can_dlc);
 433	mcp251x_hw_tx_frame(spi, buf, frame->can_dlc, tx_buf_idx);
 434
 435	/* use INSTRUCTION_RTS, to avoid "repeated frame problem" */
 436	priv->spi_tx_buf[0] = INSTRUCTION_RTS(1 << tx_buf_idx);
 437	mcp251x_spi_trans(priv->spi, 1);
 438}
 439
 440static void mcp251x_hw_rx_frame(struct spi_device *spi, u8 *buf,
 441				int buf_idx)
 442{
 443	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 444
 445	if (mcp251x_is_2510(spi)) {
 446		int i, len;
 447
 448		for (i = 1; i < RXBDAT_OFF; i++)
 449			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 450
 451		len = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 452		for (; i < (RXBDAT_OFF + len); i++)
 453			buf[i] = mcp251x_read_reg(spi, RXBCTRL(buf_idx) + i);
 454	} else {
 455		priv->spi_tx_buf[RXBCTRL_OFF] = INSTRUCTION_READ_RXB(buf_idx);
 456		mcp251x_spi_trans(spi, SPI_TRANSFER_BUF_LEN);
 457		memcpy(buf, priv->spi_rx_buf, SPI_TRANSFER_BUF_LEN);
 458	}
 459}
 460
 461static void mcp251x_hw_rx(struct spi_device *spi, int buf_idx)
 462{
 463	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 464	struct sk_buff *skb;
 465	struct can_frame *frame;
 466	u8 buf[SPI_TRANSFER_BUF_LEN];
 467
 468	skb = alloc_can_skb(priv->net, &frame);
 469	if (!skb) {
 470		dev_err(&spi->dev, "cannot allocate RX skb\n");
 471		priv->net->stats.rx_dropped++;
 472		return;
 473	}
 474
 475	mcp251x_hw_rx_frame(spi, buf, buf_idx);
 476	if (buf[RXBSIDL_OFF] & RXBSIDL_IDE) {
 477		/* Extended ID format */
 478		frame->can_id = CAN_EFF_FLAG;
 479		frame->can_id |=
 480			/* Extended ID part */
 481			SET_BYTE(buf[RXBSIDL_OFF] & RXBSIDL_EID, 2) |
 482			SET_BYTE(buf[RXBEID8_OFF], 1) |
 483			SET_BYTE(buf[RXBEID0_OFF], 0) |
 484			/* Standard ID part */
 485			(((buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 486			  (buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT)) << 18);
 487		/* Remote transmission request */
 488		if (buf[RXBDLC_OFF] & RXBDLC_RTR)
 489			frame->can_id |= CAN_RTR_FLAG;
 490	} else {
 491		/* Standard ID format */
 492		frame->can_id =
 493			(buf[RXBSIDH_OFF] << RXBSIDH_SHIFT) |
 494			(buf[RXBSIDL_OFF] >> RXBSIDL_SHIFT);
 495		if (buf[RXBSIDL_OFF] & RXBSIDL_SRR)
 496			frame->can_id |= CAN_RTR_FLAG;
 497	}
 498	/* Data length */
 499	frame->can_dlc = get_can_dlc(buf[RXBDLC_OFF] & RXBDLC_LEN_MASK);
 500	memcpy(frame->data, buf + RXBDAT_OFF, frame->can_dlc);
 501
 502	priv->net->stats.rx_packets++;
 503	priv->net->stats.rx_bytes += frame->can_dlc;
 504
 505	can_led_event(priv->net, CAN_LED_EVENT_RX);
 506
 507	netif_rx_ni(skb);
 508}
 509
 510static void mcp251x_hw_sleep(struct spi_device *spi)
 511{
 512	mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_SLEEP);
 513}
 514
 515static netdev_tx_t mcp251x_hard_start_xmit(struct sk_buff *skb,
 516					   struct net_device *net)
 517{
 518	struct mcp251x_priv *priv = netdev_priv(net);
 519	struct spi_device *spi = priv->spi;
 520
 521	if (priv->tx_skb || priv->tx_len) {
 522		dev_warn(&spi->dev, "hard_xmit called while tx busy\n");
 523		return NETDEV_TX_BUSY;
 524	}
 525
 526	if (can_dropped_invalid_skb(net, skb))
 527		return NETDEV_TX_OK;
 528
 529	netif_stop_queue(net);
 530	priv->tx_skb = skb;
 531	queue_work(priv->wq, &priv->tx_work);
 532
 533	return NETDEV_TX_OK;
 534}
 535
 536static int mcp251x_do_set_mode(struct net_device *net, enum can_mode mode)
 537{
 538	struct mcp251x_priv *priv = netdev_priv(net);
 539
 540	switch (mode) {
 541	case CAN_MODE_START:
 542		mcp251x_clean(net);
 543		/* We have to delay work since SPI I/O may sleep */
 544		priv->can.state = CAN_STATE_ERROR_ACTIVE;
 545		priv->restart_tx = 1;
 546		if (priv->can.restart_ms == 0)
 547			priv->after_suspend = AFTER_SUSPEND_RESTART;
 548		queue_work(priv->wq, &priv->restart_work);
 549		break;
 550	default:
 551		return -EOPNOTSUPP;
 552	}
 553
 554	return 0;
 555}
 556
 557static int mcp251x_set_normal_mode(struct spi_device *spi)
 558{
 559	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 560	unsigned long timeout;
 561
 562	/* Enable interrupts */
 563	mcp251x_write_reg(spi, CANINTE,
 564			  CANINTE_ERRIE | CANINTE_TX2IE | CANINTE_TX1IE |
 565			  CANINTE_TX0IE | CANINTE_RX1IE | CANINTE_RX0IE);
 566
 567	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK) {
 568		/* Put device into loopback mode */
 569		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LOOPBACK);
 570	} else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY) {
 571		/* Put device into listen-only mode */
 572		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_LISTEN_ONLY);
 573	} else {
 574		/* Put device into normal mode */
 575		mcp251x_write_reg(spi, CANCTRL, CANCTRL_REQOP_NORMAL);
 576
 577		/* Wait for the device to enter normal mode */
 578		timeout = jiffies + HZ;
 579		while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
 580			schedule();
 581			if (time_after(jiffies, timeout)) {
 582				dev_err(&spi->dev, "MCP251x didn't"
 583					" enter in normal mode\n");
 584				return -EBUSY;
 585			}
 586		}
 587	}
 588	priv->can.state = CAN_STATE_ERROR_ACTIVE;
 589	return 0;
 590}
 591
 592static int mcp251x_do_set_bittiming(struct net_device *net)
 593{
 594	struct mcp251x_priv *priv = netdev_priv(net);
 595	struct can_bittiming *bt = &priv->can.bittiming;
 596	struct spi_device *spi = priv->spi;
 597
 598	mcp251x_write_reg(spi, CNF1, ((bt->sjw - 1) << CNF1_SJW_SHIFT) |
 599			  (bt->brp - 1));
 600	mcp251x_write_reg(spi, CNF2, CNF2_BTLMODE |
 601			  (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES ?
 602			   CNF2_SAM : 0) |
 603			  ((bt->phase_seg1 - 1) << CNF2_PS1_SHIFT) |
 604			  (bt->prop_seg - 1));
 605	mcp251x_write_bits(spi, CNF3, CNF3_PHSEG2_MASK,
 606			   (bt->phase_seg2 - 1));
 607	dev_dbg(&spi->dev, "CNF: 0x%02x 0x%02x 0x%02x\n",
 608		mcp251x_read_reg(spi, CNF1),
 609		mcp251x_read_reg(spi, CNF2),
 610		mcp251x_read_reg(spi, CNF3));
 611
 612	return 0;
 613}
 614
 615static int mcp251x_setup(struct net_device *net, struct mcp251x_priv *priv,
 616			 struct spi_device *spi)
 617{
 618	mcp251x_do_set_bittiming(net);
 619
 620	mcp251x_write_reg(spi, RXBCTRL(0),
 621			  RXBCTRL_BUKT | RXBCTRL_RXM0 | RXBCTRL_RXM1);
 622	mcp251x_write_reg(spi, RXBCTRL(1),
 623			  RXBCTRL_RXM0 | RXBCTRL_RXM1);
 624	return 0;
 625}
 626
 627static int mcp251x_hw_reset(struct spi_device *spi)
 628{
 629	struct mcp251x_priv *priv = spi_get_drvdata(spi);
 630	u8 reg;
 631	int ret;
 632
 633	/* Wait for oscillator startup timer after power up */
 634	mdelay(MCP251X_OST_DELAY_MS);
 635
 636	priv->spi_tx_buf[0] = INSTRUCTION_RESET;
 637	ret = mcp251x_spi_trans(spi, 1);
 638	if (ret)
 639		return ret;
 640
 641	/* Wait for oscillator startup timer after reset */
 642	mdelay(MCP251X_OST_DELAY_MS);
 643	
 644	reg = mcp251x_read_reg(spi, CANSTAT);
 645	if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF)
 646		return -ENODEV;
 647
 648	return 0;
 649}
 650
 651static int mcp251x_hw_probe(struct spi_device *spi)
 652{
 653	u8 ctrl;
 654	int ret;
 655
 656	ret = mcp251x_hw_reset(spi);
 657	if (ret)
 658		return ret;
 659
 660	ctrl = mcp251x_read_reg(spi, CANCTRL);
 661
 662	dev_dbg(&spi->dev, "CANCTRL 0x%02x\n", ctrl);
 663
 664	/* Check for power up default value */
 665	if ((ctrl & 0x17) != 0x07)
 666		return -ENODEV;
 667
 668	return 0;
 669}
 670
 671static int mcp251x_power_enable(struct regulator *reg, int enable)
 672{
 673	if (IS_ERR_OR_NULL(reg))
 674		return 0;
 675
 676	if (enable)
 677		return regulator_enable(reg);
 678	else
 679		return regulator_disable(reg);
 680}
 681
 682static void mcp251x_open_clean(struct net_device *net)
 683{
 684	struct mcp251x_priv *priv = netdev_priv(net);
 685	struct spi_device *spi = priv->spi;
 686
 687	free_irq(spi->irq, priv);
 688	mcp251x_hw_sleep(spi);
 689	mcp251x_power_enable(priv->transceiver, 0);
 690	close_candev(net);
 691}
 692
 693static int mcp251x_stop(struct net_device *net)
 694{
 695	struct mcp251x_priv *priv = netdev_priv(net);
 696	struct spi_device *spi = priv->spi;
 697
 698	close_candev(net);
 699
 700	priv->force_quit = 1;
 701	free_irq(spi->irq, priv);
 702	destroy_workqueue(priv->wq);
 703	priv->wq = NULL;
 704
 705	mutex_lock(&priv->mcp_lock);
 706
 707	/* Disable and clear pending interrupts */
 708	mcp251x_write_reg(spi, CANINTE, 0x00);
 709	mcp251x_write_reg(spi, CANINTF, 0x00);
 710
 711	mcp251x_write_reg(spi, TXBCTRL(0), 0);
 712	mcp251x_clean(net);
 713
 714	mcp251x_hw_sleep(spi);
 715
 716	mcp251x_power_enable(priv->transceiver, 0);
 717
 718	priv->can.state = CAN_STATE_STOPPED;
 719
 720	mutex_unlock(&priv->mcp_lock);
 721
 722	can_led_event(net, CAN_LED_EVENT_STOP);
 723
 724	return 0;
 725}
 726
 727static void mcp251x_error_skb(struct net_device *net, int can_id, int data1)
 728{
 729	struct sk_buff *skb;
 730	struct can_frame *frame;
 731
 732	skb = alloc_can_err_skb(net, &frame);
 733	if (skb) {
 734		frame->can_id |= can_id;
 735		frame->data[1] = data1;
 736		netif_rx_ni(skb);
 737	} else {
 738		netdev_err(net, "cannot allocate error skb\n");
 739	}
 740}
 741
 742static void mcp251x_tx_work_handler(struct work_struct *ws)
 743{
 744	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
 745						 tx_work);
 746	struct spi_device *spi = priv->spi;
 747	struct net_device *net = priv->net;
 748	struct can_frame *frame;
 749
 750	mutex_lock(&priv->mcp_lock);
 751	if (priv->tx_skb) {
 752		if (priv->can.state == CAN_STATE_BUS_OFF) {
 753			mcp251x_clean(net);
 754		} else {
 755			frame = (struct can_frame *)priv->tx_skb->data;
 756
 757			if (frame->can_dlc > CAN_FRAME_MAX_DATA_LEN)
 758				frame->can_dlc = CAN_FRAME_MAX_DATA_LEN;
 759			mcp251x_hw_tx(spi, frame, 0);
 760			priv->tx_len = 1 + frame->can_dlc;
 761			can_put_echo_skb(priv->tx_skb, net, 0);
 762			priv->tx_skb = NULL;
 763		}
 764	}
 765	mutex_unlock(&priv->mcp_lock);
 766}
 767
 768static void mcp251x_restart_work_handler(struct work_struct *ws)
 769{
 770	struct mcp251x_priv *priv = container_of(ws, struct mcp251x_priv,
 771						 restart_work);
 772	struct spi_device *spi = priv->spi;
 773	struct net_device *net = priv->net;
 774
 775	mutex_lock(&priv->mcp_lock);
 776	if (priv->after_suspend) {
 777		mcp251x_hw_reset(spi);
 778		mcp251x_setup(net, priv, spi);
 779		if (priv->after_suspend & AFTER_SUSPEND_RESTART) {
 780			mcp251x_set_normal_mode(spi);
 781		} else if (priv->after_suspend & AFTER_SUSPEND_UP) {
 782			netif_device_attach(net);
 783			mcp251x_clean(net);
 784			mcp251x_set_normal_mode(spi);
 785			netif_wake_queue(net);
 786		} else {
 787			mcp251x_hw_sleep(spi);
 788		}
 789		priv->after_suspend = 0;
 790		priv->force_quit = 0;
 791	}
 792
 793	if (priv->restart_tx) {
 794		priv->restart_tx = 0;
 795		mcp251x_write_reg(spi, TXBCTRL(0), 0);
 796		mcp251x_clean(net);
 797		netif_wake_queue(net);
 798		mcp251x_error_skb(net, CAN_ERR_RESTARTED, 0);
 799	}
 800	mutex_unlock(&priv->mcp_lock);
 801}
 802
 803static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
 804{
 805	struct mcp251x_priv *priv = dev_id;
 806	struct spi_device *spi = priv->spi;
 807	struct net_device *net = priv->net;
 808
 809	mutex_lock(&priv->mcp_lock);
 810	while (!priv->force_quit) {
 811		enum can_state new_state;
 812		u8 intf, eflag;
 813		u8 clear_intf = 0;
 814		int can_id = 0, data1 = 0;
 815
 816		mcp251x_read_2regs(spi, CANINTF, &intf, &eflag);
 817
 818		/* mask out flags we don't care about */
 819		intf &= CANINTF_RX | CANINTF_TX | CANINTF_ERR;
 820
 821		/* receive buffer 0 */
 822		if (intf & CANINTF_RX0IF) {
 823			mcp251x_hw_rx(spi, 0);
 824			/*
 825			 * Free one buffer ASAP
 826			 * (The MCP2515 does this automatically.)
 827			 */
 828			if (mcp251x_is_2510(spi))
 829				mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
 830		}
 831
 832		/* receive buffer 1 */
 833		if (intf & CANINTF_RX1IF) {
 834			mcp251x_hw_rx(spi, 1);
 835			/* the MCP2515 does this automatically */
 836			if (mcp251x_is_2510(spi))
 837				clear_intf |= CANINTF_RX1IF;
 838		}
 839
 840		/* any error or tx interrupt we need to clear? */
 841		if (intf & (CANINTF_ERR | CANINTF_TX))
 842			clear_intf |= intf & (CANINTF_ERR | CANINTF_TX);
 843		if (clear_intf)
 844			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
 845
 846		if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR))
 847			mcp251x_write_bits(spi, EFLG, eflag, 0x00);
 848
 849		/* Update can state */
 850		if (eflag & EFLG_TXBO) {
 851			new_state = CAN_STATE_BUS_OFF;
 852			can_id |= CAN_ERR_BUSOFF;
 853		} else if (eflag & EFLG_TXEP) {
 854			new_state = CAN_STATE_ERROR_PASSIVE;
 855			can_id |= CAN_ERR_CRTL;
 856			data1 |= CAN_ERR_CRTL_TX_PASSIVE;
 857		} else if (eflag & EFLG_RXEP) {
 858			new_state = CAN_STATE_ERROR_PASSIVE;
 859			can_id |= CAN_ERR_CRTL;
 860			data1 |= CAN_ERR_CRTL_RX_PASSIVE;
 861		} else if (eflag & EFLG_TXWAR) {
 862			new_state = CAN_STATE_ERROR_WARNING;
 863			can_id |= CAN_ERR_CRTL;
 864			data1 |= CAN_ERR_CRTL_TX_WARNING;
 865		} else if (eflag & EFLG_RXWAR) {
 866			new_state = CAN_STATE_ERROR_WARNING;
 867			can_id |= CAN_ERR_CRTL;
 868			data1 |= CAN_ERR_CRTL_RX_WARNING;
 869		} else {
 870			new_state = CAN_STATE_ERROR_ACTIVE;
 871		}
 872
 873		/* Update can state statistics */
 874		switch (priv->can.state) {
 875		case CAN_STATE_ERROR_ACTIVE:
 876			if (new_state >= CAN_STATE_ERROR_WARNING &&
 877			    new_state <= CAN_STATE_BUS_OFF)
 878				priv->can.can_stats.error_warning++;
 879		case CAN_STATE_ERROR_WARNING:	/* fallthrough */
 880			if (new_state >= CAN_STATE_ERROR_PASSIVE &&
 881			    new_state <= CAN_STATE_BUS_OFF)
 882				priv->can.can_stats.error_passive++;
 883			break;
 884		default:
 885			break;
 886		}
 887		priv->can.state = new_state;
 888
 889		if (intf & CANINTF_ERRIF) {
 890			/* Handle overflow counters */
 891			if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR)) {
 892				if (eflag & EFLG_RX0OVR) {
 893					net->stats.rx_over_errors++;
 894					net->stats.rx_errors++;
 895				}
 896				if (eflag & EFLG_RX1OVR) {
 897					net->stats.rx_over_errors++;
 898					net->stats.rx_errors++;
 899				}
 900				can_id |= CAN_ERR_CRTL;
 901				data1 |= CAN_ERR_CRTL_RX_OVERFLOW;
 902			}
 903			mcp251x_error_skb(net, can_id, data1);
 904		}
 905
 906		if (priv->can.state == CAN_STATE_BUS_OFF) {
 907			if (priv->can.restart_ms == 0) {
 908				priv->force_quit = 1;
 909				priv->can.can_stats.bus_off++;
 910				can_bus_off(net);
 911				mcp251x_hw_sleep(spi);
 912				break;
 913			}
 914		}
 915
 916		if (intf == 0)
 917			break;
 918
 919		if (intf & CANINTF_TX) {
 920			net->stats.tx_packets++;
 921			net->stats.tx_bytes += priv->tx_len - 1;
 922			can_led_event(net, CAN_LED_EVENT_TX);
 923			if (priv->tx_len) {
 924				can_get_echo_skb(net, 0);
 925				priv->tx_len = 0;
 926			}
 927			netif_wake_queue(net);
 928		}
 929
 930	}
 931	mutex_unlock(&priv->mcp_lock);
 932	return IRQ_HANDLED;
 933}
 934
 935static int mcp251x_open(struct net_device *net)
 936{
 937	struct mcp251x_priv *priv = netdev_priv(net);
 938	struct spi_device *spi = priv->spi;
 939	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
 940	int ret;
 941
 942	ret = open_candev(net);
 943	if (ret) {
 944		dev_err(&spi->dev, "unable to set initial baudrate!\n");
 945		return ret;
 946	}
 947
 948	mutex_lock(&priv->mcp_lock);
 949	mcp251x_power_enable(priv->transceiver, 1);
 950
 951	priv->force_quit = 0;
 952	priv->tx_skb = NULL;
 953	priv->tx_len = 0;
 954
 955	ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
 956				   flags | IRQF_ONESHOT, DEVICE_NAME, priv);
 957	if (ret) {
 958		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
 959		mcp251x_power_enable(priv->transceiver, 0);
 960		close_candev(net);
 961		goto open_unlock;
 962	}
 963
 964	priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
 965				   0);
 966	INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
 967	INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
 968
 969	ret = mcp251x_hw_reset(spi);
 970	if (ret) {
 971		mcp251x_open_clean(net);
 972		goto open_unlock;
 973	}
 974	ret = mcp251x_setup(net, priv, spi);
 975	if (ret) {
 976		mcp251x_open_clean(net);
 977		goto open_unlock;
 978	}
 979	ret = mcp251x_set_normal_mode(spi);
 980	if (ret) {
 981		mcp251x_open_clean(net);
 982		goto open_unlock;
 983	}
 984
 985	can_led_event(net, CAN_LED_EVENT_OPEN);
 986
 987	netif_wake_queue(net);
 988
 989open_unlock:
 990	mutex_unlock(&priv->mcp_lock);
 991	return ret;
 992}
 993
 994static const struct net_device_ops mcp251x_netdev_ops = {
 995	.ndo_open = mcp251x_open,
 996	.ndo_stop = mcp251x_stop,
 997	.ndo_start_xmit = mcp251x_hard_start_xmit,
 998	.ndo_change_mtu = can_change_mtu,
 999};
1000
1001static const struct of_device_id mcp251x_of_match[] = {
1002	{
1003		.compatible	= "microchip,mcp2510",
1004		.data		= (void *)CAN_MCP251X_MCP2510,
1005	},
1006	{
1007		.compatible	= "microchip,mcp2515",
1008		.data		= (void *)CAN_MCP251X_MCP2515,
1009	},
1010	{ }
1011};
1012MODULE_DEVICE_TABLE(of, mcp251x_of_match);
1013
1014static const struct spi_device_id mcp251x_id_table[] = {
1015	{
1016		.name		= "mcp2510",
1017		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2510,
1018	},
1019	{
1020		.name		= "mcp2515",
1021		.driver_data	= (kernel_ulong_t)CAN_MCP251X_MCP2515,
1022	},
1023	{ }
1024};
1025MODULE_DEVICE_TABLE(spi, mcp251x_id_table);
1026
1027static int mcp251x_can_probe(struct spi_device *spi)
1028{
1029	const struct of_device_id *of_id = of_match_device(mcp251x_of_match,
1030							   &spi->dev);
1031	struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev);
1032	struct net_device *net;
1033	struct mcp251x_priv *priv;
1034	struct clk *clk;
1035	int freq, ret;
1036
1037	clk = devm_clk_get(&spi->dev, NULL);
1038	if (IS_ERR(clk)) {
1039		if (pdata)
1040			freq = pdata->oscillator_frequency;
1041		else
1042			return PTR_ERR(clk);
1043	} else {
1044		freq = clk_get_rate(clk);
1045	}
1046
1047	/* Sanity check */
1048	if (freq < 1000000 || freq > 25000000)
1049		return -ERANGE;
1050
1051	/* Allocate can/net device */
1052	net = alloc_candev(sizeof(struct mcp251x_priv), TX_ECHO_SKB_MAX);
1053	if (!net)
1054		return -ENOMEM;
1055
1056	if (!IS_ERR(clk)) {
1057		ret = clk_prepare_enable(clk);
1058		if (ret)
1059			goto out_free;
1060	}
1061
1062	net->netdev_ops = &mcp251x_netdev_ops;
1063	net->flags |= IFF_ECHO;
1064
1065	priv = netdev_priv(net);
1066	priv->can.bittiming_const = &mcp251x_bittiming_const;
1067	priv->can.do_set_mode = mcp251x_do_set_mode;
1068	priv->can.clock.freq = freq / 2;
1069	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
1070		CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY;
1071	if (of_id)
1072		priv->model = (enum mcp251x_model)of_id->data;
1073	else
1074		priv->model = spi_get_device_id(spi)->driver_data;
1075	priv->net = net;
1076	priv->clk = clk;
1077
1078	spi_set_drvdata(spi, priv);
1079
1080	/* Configure the SPI bus */
1081	spi->bits_per_word = 8;
1082	if (mcp251x_is_2510(spi))
1083		spi->max_speed_hz = spi->max_speed_hz ? : 5 * 1000 * 1000;
1084	else
1085		spi->max_speed_hz = spi->max_speed_hz ? : 10 * 1000 * 1000;
1086	ret = spi_setup(spi);
1087	if (ret)
1088		goto out_clk;
1089
1090	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");
1091	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");
1092	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||
1093	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {
1094		ret = -EPROBE_DEFER;
1095		goto out_clk;
1096	}
1097
1098	ret = mcp251x_power_enable(priv->power, 1);
1099	if (ret)
1100		goto out_clk;
1101
1102	priv->spi = spi;
1103	mutex_init(&priv->mcp_lock);
1104
1105	/* If requested, allocate DMA buffers */
1106	if (mcp251x_enable_dma) {
1107		spi->dev.coherent_dma_mask = ~0;
1108
1109		/*
1110		 * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
1111		 * that much and share it between Tx and Rx DMA buffers.
1112		 */
1113		priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
1114						       PAGE_SIZE,
1115						       &priv->spi_tx_dma,
1116						       GFP_DMA);
1117
1118		if (priv->spi_tx_buf) {
1119			priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
1120			priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
1121							(PAGE_SIZE / 2));
1122		} else {
1123			/* Fall back to non-DMA */
1124			mcp251x_enable_dma = 0;
1125		}
1126	}
1127
1128	/* Allocate non-DMA buffers */
1129	if (!mcp251x_enable_dma) {
1130		priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1131						GFP_KERNEL);
1132		if (!priv->spi_tx_buf) {
1133			ret = -ENOMEM;
1134			goto error_probe;
1135		}
1136		priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
1137						GFP_KERNEL);
1138		if (!priv->spi_rx_buf) {
1139			ret = -ENOMEM;
1140			goto error_probe;
1141		}
1142	}
1143
1144	SET_NETDEV_DEV(net, &spi->dev);
1145
1146	/* Here is OK to not lock the MCP, no one knows about it yet */
1147	ret = mcp251x_hw_probe(spi);
1148	if (ret) {
1149		if (ret == -ENODEV)
1150			dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n", priv->model);
1151		goto error_probe;
1152	}
1153
1154	mcp251x_hw_sleep(spi);
1155
1156	ret = register_candev(net);
1157	if (ret)
1158		goto error_probe;
1159
1160	devm_can_led_init(net);
1161
1162	netdev_info(net, "MCP%x successfully initialized.\n", priv->model);
1163	return 0;
1164
1165error_probe:
1166	mcp251x_power_enable(priv->power, 0);
1167
1168out_clk:
1169	if (!IS_ERR(clk))
1170		clk_disable_unprepare(clk);
1171
1172out_free:
1173	free_candev(net);
1174
1175	dev_err(&spi->dev, "Probe failed, err=%d\n", -ret);
1176	return ret;
1177}
1178
1179static int mcp251x_can_remove(struct spi_device *spi)
1180{
1181	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1182	struct net_device *net = priv->net;
1183
1184	unregister_candev(net);
1185
1186	mcp251x_power_enable(priv->power, 0);
1187
1188	if (!IS_ERR(priv->clk))
1189		clk_disable_unprepare(priv->clk);
1190
1191	free_candev(net);
1192
1193	return 0;
1194}
1195
1196static int __maybe_unused mcp251x_can_suspend(struct device *dev)
1197{
1198	struct spi_device *spi = to_spi_device(dev);
1199	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1200	struct net_device *net = priv->net;
1201
1202	priv->force_quit = 1;
1203	disable_irq(spi->irq);
1204	/*
1205	 * Note: at this point neither IST nor workqueues are running.
1206	 * open/stop cannot be called anyway so locking is not needed
1207	 */
1208	if (netif_running(net)) {
1209		netif_device_detach(net);
1210
1211		mcp251x_hw_sleep(spi);
1212		mcp251x_power_enable(priv->transceiver, 0);
1213		priv->after_suspend = AFTER_SUSPEND_UP;
1214	} else {
1215		priv->after_suspend = AFTER_SUSPEND_DOWN;
1216	}
1217
1218	if (!IS_ERR_OR_NULL(priv->power)) {
1219		regulator_disable(priv->power);
1220		priv->after_suspend |= AFTER_SUSPEND_POWER;
1221	}
1222
1223	return 0;
1224}
1225
1226static int __maybe_unused mcp251x_can_resume(struct device *dev)
1227{
1228	struct spi_device *spi = to_spi_device(dev);
1229	struct mcp251x_priv *priv = spi_get_drvdata(spi);
1230
1231	if (priv->after_suspend & AFTER_SUSPEND_POWER)
1232		mcp251x_power_enable(priv->power, 1);
1233
1234	if (priv->after_suspend & AFTER_SUSPEND_UP) {
1235		mcp251x_power_enable(priv->transceiver, 1);
1236		queue_work(priv->wq, &priv->restart_work);
1237	} else {
1238		priv->after_suspend = 0;
1239	}
1240
1241	priv->force_quit = 0;
1242	enable_irq(spi->irq);
1243	return 0;
1244}
1245
1246static SIMPLE_DEV_PM_OPS(mcp251x_can_pm_ops, mcp251x_can_suspend,
1247	mcp251x_can_resume);
1248
1249static struct spi_driver mcp251x_can_driver = {
1250	.driver = {
1251		.name = DEVICE_NAME,
1252		.of_match_table = mcp251x_of_match,
1253		.pm = &mcp251x_can_pm_ops,
1254	},
1255	.id_table = mcp251x_id_table,
1256	.probe = mcp251x_can_probe,
1257	.remove = mcp251x_can_remove,
1258};
1259module_spi_driver(mcp251x_can_driver);
1260
1261MODULE_AUTHOR("Chris Elston <celston@katalix.com>, "
1262	      "Christian Pellegrin <chripell@evolware.org>");
1263MODULE_DESCRIPTION("Microchip 251x CAN driver");
1264MODULE_LICENSE("GPL v2");