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1// SPDX-License-Identifier: GPL-2.0-only2/* CAN bus driver for Holt HI3110 CAN Controller with SPI Interface3 *4 * Copyright(C) Timesys Corporation 20165 *6 * Based on Microchip 251x CAN Controller (mcp251x) Linux kernel driver7 * Copyright 2009 Christian Pellegrin EVOL S.r.l.8 * Copyright 2007 Raymarine UK, Ltd. All Rights Reserved.9 * Copyright 2006 Arcom Control Systems Ltd.10 *11 * Based on CAN bus driver for the CCAN controller written by12 * - Sascha Hauer, Marc Kleine-Budde, Pengutronix13 * - Simon Kallweit, intefo AG14 * Copyright 200715 */16 17#include <linux/can/core.h>18#include <linux/can/dev.h>19#include <linux/clk.h>20#include <linux/completion.h>21#include <linux/delay.h>22#include <linux/device.h>23#include <linux/ethtool.h>24#include <linux/freezer.h>25#include <linux/interrupt.h>26#include <linux/io.h>27#include <linux/kernel.h>28#include <linux/mod_devicetable.h>29#include <linux/module.h>30#include <linux/netdevice.h>31#include <linux/platform_device.h>32#include <linux/property.h>33#include <linux/regulator/consumer.h>34#include <linux/slab.h>35#include <linux/spi/spi.h>36#include <linux/uaccess.h>37 38#define HI3110_MASTER_RESET 0x5639#define HI3110_READ_CTRL0 0xD240#define HI3110_READ_CTRL1 0xD441#define HI3110_READ_STATF 0xE242#define HI3110_WRITE_CTRL0 0x1443#define HI3110_WRITE_CTRL1 0x1644#define HI3110_WRITE_INTE 0x1C45#define HI3110_WRITE_BTR0 0x1846#define HI3110_WRITE_BTR1 0x1A47#define HI3110_READ_BTR0 0xD648#define HI3110_READ_BTR1 0xD849#define HI3110_READ_INTF 0xDE50#define HI3110_READ_ERR 0xDC51#define HI3110_READ_FIFO_WOTIME 0x4852#define HI3110_WRITE_FIFO 0x1253#define HI3110_READ_MESSTAT 0xDA54#define HI3110_READ_REC 0xEA55#define HI3110_READ_TEC 0xEC56 57#define HI3110_CTRL0_MODE_MASK (7 << 5)58#define HI3110_CTRL0_NORMAL_MODE (0 << 5)59#define HI3110_CTRL0_LOOPBACK_MODE (1 << 5)60#define HI3110_CTRL0_MONITOR_MODE (2 << 5)61#define HI3110_CTRL0_SLEEP_MODE (3 << 5)62#define HI3110_CTRL0_INIT_MODE (4 << 5)63 64#define HI3110_CTRL1_TXEN BIT(7)65 66#define HI3110_INT_RXTMP BIT(7)67#define HI3110_INT_RXFIFO BIT(6)68#define HI3110_INT_TXCPLT BIT(5)69#define HI3110_INT_BUSERR BIT(4)70#define HI3110_INT_MCHG BIT(3)71#define HI3110_INT_WAKEUP BIT(2)72#define HI3110_INT_F1MESS BIT(1)73#define HI3110_INT_F0MESS BIT(0)74 75#define HI3110_ERR_BUSOFF BIT(7)76#define HI3110_ERR_TXERRP BIT(6)77#define HI3110_ERR_RXERRP BIT(5)78#define HI3110_ERR_BITERR BIT(4)79#define HI3110_ERR_FRMERR BIT(3)80#define HI3110_ERR_CRCERR BIT(2)81#define HI3110_ERR_ACKERR BIT(1)82#define HI3110_ERR_STUFERR BIT(0)83#define HI3110_ERR_PROTOCOL_MASK (0x1F)84#define HI3110_ERR_PASSIVE_MASK (0x60)85 86#define HI3110_STAT_RXFMTY BIT(1)87#define HI3110_STAT_BUSOFF BIT(2)88#define HI3110_STAT_ERRP BIT(3)89#define HI3110_STAT_ERRW BIT(4)90#define HI3110_STAT_TXMTY BIT(7)91 92#define HI3110_BTR0_SJW_SHIFT 693#define HI3110_BTR0_BRP_SHIFT 094 95#define HI3110_BTR1_SAMP_3PERBIT (1 << 7)96#define HI3110_BTR1_SAMP_1PERBIT (0 << 7)97#define HI3110_BTR1_TSEG2_SHIFT 498#define HI3110_BTR1_TSEG1_SHIFT 099 100#define HI3110_FIFO_WOTIME_TAG_OFF 0101#define HI3110_FIFO_WOTIME_ID_OFF 1102#define HI3110_FIFO_WOTIME_DLC_OFF 5103#define HI3110_FIFO_WOTIME_DAT_OFF 6104 105#define HI3110_FIFO_WOTIME_TAG_IDE BIT(7)106#define HI3110_FIFO_WOTIME_ID_RTR BIT(0)107 108#define HI3110_FIFO_TAG_OFF 0109#define HI3110_FIFO_ID_OFF 1110#define HI3110_FIFO_STD_DLC_OFF 3111#define HI3110_FIFO_STD_DATA_OFF 4112#define HI3110_FIFO_EXT_DLC_OFF 5113#define HI3110_FIFO_EXT_DATA_OFF 6114 115#define HI3110_CAN_MAX_DATA_LEN 8116#define HI3110_RX_BUF_LEN 15117#define HI3110_TX_STD_BUF_LEN 12118#define HI3110_TX_EXT_BUF_LEN 14119#define HI3110_CAN_FRAME_MAX_BITS 128120#define HI3110_EFF_FLAGS 0x18 /* IDE + SRR */121 122#define HI3110_TX_ECHO_SKB_MAX 1123 124#define HI3110_OST_DELAY_MS (10)125 126#define DEVICE_NAME "hi3110"127 128static const struct can_bittiming_const hi3110_bittiming_const = {129	.name = DEVICE_NAME,130	.tseg1_min = 2,131	.tseg1_max = 16,132	.tseg2_min = 2,133	.tseg2_max = 8,134	.sjw_max = 4,135	.brp_min = 1,136	.brp_max = 64,137	.brp_inc = 1,138};139 140enum hi3110_model {141	CAN_HI3110_HI3110 = 0x3110,142};143 144struct hi3110_priv {145	struct can_priv can;146	struct net_device *net;147	struct spi_device *spi;148	enum hi3110_model model;149 150	struct mutex hi3110_lock; /* SPI device lock */151 152	u8 *spi_tx_buf;153	u8 *spi_rx_buf;154 155	struct sk_buff *tx_skb;156 157	struct workqueue_struct *wq;158	struct work_struct tx_work;159	struct work_struct restart_work;160 161	int force_quit;162	int after_suspend;163#define HI3110_AFTER_SUSPEND_UP 1164#define HI3110_AFTER_SUSPEND_DOWN 2165#define HI3110_AFTER_SUSPEND_POWER 4166#define HI3110_AFTER_SUSPEND_RESTART 8167	int restart_tx;168	bool tx_busy;169 170	struct regulator *power;171	struct regulator *transceiver;172	struct clk *clk;173};174 175static void hi3110_clean(struct net_device *net)176{177	struct hi3110_priv *priv = netdev_priv(net);178 179	if (priv->tx_skb || priv->tx_busy)180		net->stats.tx_errors++;181	dev_kfree_skb(priv->tx_skb);182	if (priv->tx_busy)183		can_free_echo_skb(priv->net, 0, NULL);184	priv->tx_skb = NULL;185	priv->tx_busy = false;186}187 188/* Note about handling of error return of hi3110_spi_trans: accessing189 * registers via SPI is not really different conceptually than using190 * normal I/O assembler instructions, although it's much more191 * complicated from a practical POV. So it's not advisable to always192 * check the return value of this function. Imagine that every193 * read{b,l}, write{b,l} and friends would be bracketed in "if ( < 0)194 * error();", it would be a great mess (well there are some situation195 * when exception handling C++ like could be useful after all). So we196 * just check that transfers are OK at the beginning of our197 * conversation with the chip and to avoid doing really nasty things198 * (like injecting bogus packets in the network stack).199 */200static int hi3110_spi_trans(struct spi_device *spi, int len)201{202	struct hi3110_priv *priv = spi_get_drvdata(spi);203	struct spi_transfer t = {204		.tx_buf = priv->spi_tx_buf,205		.rx_buf = priv->spi_rx_buf,206		.len = len,207		.cs_change = 0,208	};209	struct spi_message m;210	int ret;211 212	spi_message_init(&m);213	spi_message_add_tail(&t, &m);214 215	ret = spi_sync(spi, &m);216 217	if (ret)218		dev_err(&spi->dev, "spi transfer failed: ret = %d\n", ret);219	return ret;220}221 222static int hi3110_cmd(struct spi_device *spi, u8 command)223{224	struct hi3110_priv *priv = spi_get_drvdata(spi);225 226	priv->spi_tx_buf[0] = command;227	dev_dbg(&spi->dev, "hi3110_cmd: %02X\n", command);228 229	return hi3110_spi_trans(spi, 1);230}231 232static u8 hi3110_read(struct spi_device *spi, u8 command)233{234	struct hi3110_priv *priv = spi_get_drvdata(spi);235	u8 val = 0;236 237	priv->spi_tx_buf[0] = command;238	hi3110_spi_trans(spi, 2);239	val = priv->spi_rx_buf[1];240 241	return val;242}243 244static void hi3110_write(struct spi_device *spi, u8 reg, u8 val)245{246	struct hi3110_priv *priv = spi_get_drvdata(spi);247 248	priv->spi_tx_buf[0] = reg;249	priv->spi_tx_buf[1] = val;250	hi3110_spi_trans(spi, 2);251}252 253static void hi3110_hw_tx_frame(struct spi_device *spi, u8 *buf, int len)254{255	struct hi3110_priv *priv = spi_get_drvdata(spi);256 257	priv->spi_tx_buf[0] = HI3110_WRITE_FIFO;258	memcpy(priv->spi_tx_buf + 1, buf, len);259	hi3110_spi_trans(spi, len + 1);260}261 262static void hi3110_hw_tx(struct spi_device *spi, struct can_frame *frame)263{264	u8 buf[HI3110_TX_EXT_BUF_LEN];265 266	buf[HI3110_FIFO_TAG_OFF] = 0;267 268	if (frame->can_id & CAN_EFF_FLAG) {269		/* Extended frame */270		buf[HI3110_FIFO_ID_OFF] = (frame->can_id & CAN_EFF_MASK) >> 21;271		buf[HI3110_FIFO_ID_OFF + 1] =272			(((frame->can_id & CAN_EFF_MASK) >> 13) & 0xe0) |273			HI3110_EFF_FLAGS |274			(((frame->can_id & CAN_EFF_MASK) >> 15) & 0x07);275		buf[HI3110_FIFO_ID_OFF + 2] =276			(frame->can_id & CAN_EFF_MASK) >> 7;277		buf[HI3110_FIFO_ID_OFF + 3] =278			((frame->can_id & CAN_EFF_MASK) << 1) |279			((frame->can_id & CAN_RTR_FLAG) ? 1 : 0);280 281		buf[HI3110_FIFO_EXT_DLC_OFF] = frame->len;282 283		memcpy(buf + HI3110_FIFO_EXT_DATA_OFF,284		       frame->data, frame->len);285 286		hi3110_hw_tx_frame(spi, buf, HI3110_TX_EXT_BUF_LEN -287				   (HI3110_CAN_MAX_DATA_LEN - frame->len));288	} else {289		/* Standard frame */290		buf[HI3110_FIFO_ID_OFF] =   (frame->can_id & CAN_SFF_MASK) >> 3;291		buf[HI3110_FIFO_ID_OFF + 1] =292			((frame->can_id & CAN_SFF_MASK) << 5) |293			((frame->can_id & CAN_RTR_FLAG) ? (1 << 4) : 0);294 295		buf[HI3110_FIFO_STD_DLC_OFF] = frame->len;296 297		memcpy(buf + HI3110_FIFO_STD_DATA_OFF,298		       frame->data, frame->len);299 300		hi3110_hw_tx_frame(spi, buf, HI3110_TX_STD_BUF_LEN -301				   (HI3110_CAN_MAX_DATA_LEN - frame->len));302	}303}304 305static void hi3110_hw_rx_frame(struct spi_device *spi, u8 *buf)306{307	struct hi3110_priv *priv = spi_get_drvdata(spi);308 309	priv->spi_tx_buf[0] = HI3110_READ_FIFO_WOTIME;310	hi3110_spi_trans(spi, HI3110_RX_BUF_LEN);311	memcpy(buf, priv->spi_rx_buf + 1, HI3110_RX_BUF_LEN - 1);312}313 314static void hi3110_hw_rx(struct spi_device *spi)315{316	struct hi3110_priv *priv = spi_get_drvdata(spi);317	struct sk_buff *skb;318	struct can_frame *frame;319	u8 buf[HI3110_RX_BUF_LEN - 1];320 321	skb = alloc_can_skb(priv->net, &frame);322	if (!skb) {323		priv->net->stats.rx_dropped++;324		return;325	}326 327	hi3110_hw_rx_frame(spi, buf);328	if (buf[HI3110_FIFO_WOTIME_TAG_OFF] & HI3110_FIFO_WOTIME_TAG_IDE) {329		/* IDE is recessive (1), indicating extended 29-bit frame */330		frame->can_id = CAN_EFF_FLAG;331		frame->can_id |=332			(buf[HI3110_FIFO_WOTIME_ID_OFF] << 21) |333			(((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5) << 18) |334			((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0x07) << 15) |335			(buf[HI3110_FIFO_WOTIME_ID_OFF + 2] << 7) |336			(buf[HI3110_FIFO_WOTIME_ID_OFF + 3] >> 1);337	} else {338		/* IDE is dominant (0), frame indicating standard 11-bit */339		frame->can_id =340			(buf[HI3110_FIFO_WOTIME_ID_OFF] << 3) |341			((buf[HI3110_FIFO_WOTIME_ID_OFF + 1] & 0xE0) >> 5);342	}343 344	/* Data length */345	frame->len = can_cc_dlc2len(buf[HI3110_FIFO_WOTIME_DLC_OFF] & 0x0F);346 347	if (buf[HI3110_FIFO_WOTIME_ID_OFF + 3] & HI3110_FIFO_WOTIME_ID_RTR) {348		frame->can_id |= CAN_RTR_FLAG;349	} else {350		memcpy(frame->data, buf + HI3110_FIFO_WOTIME_DAT_OFF,351		       frame->len);352 353		priv->net->stats.rx_bytes += frame->len;354	}355	priv->net->stats.rx_packets++;356 357	netif_rx(skb);358}359 360static void hi3110_hw_sleep(struct spi_device *spi)361{362	hi3110_write(spi, HI3110_WRITE_CTRL0, HI3110_CTRL0_SLEEP_MODE);363}364 365static netdev_tx_t hi3110_hard_start_xmit(struct sk_buff *skb,366					  struct net_device *net)367{368	struct hi3110_priv *priv = netdev_priv(net);369	struct spi_device *spi = priv->spi;370 371	if (priv->tx_skb || priv->tx_busy) {372		dev_err(&spi->dev, "hard_xmit called while tx busy\n");373		return NETDEV_TX_BUSY;374	}375 376	if (can_dev_dropped_skb(net, skb))377		return NETDEV_TX_OK;378 379	netif_stop_queue(net);380	priv->tx_skb = skb;381	queue_work(priv->wq, &priv->tx_work);382 383	return NETDEV_TX_OK;384}385 386static int hi3110_do_set_mode(struct net_device *net, enum can_mode mode)387{388	struct hi3110_priv *priv = netdev_priv(net);389 390	switch (mode) {391	case CAN_MODE_START:392		hi3110_clean(net);393		/* We have to delay work since SPI I/O may sleep */394		priv->can.state = CAN_STATE_ERROR_ACTIVE;395		priv->restart_tx = 1;396		if (priv->can.restart_ms == 0)397			priv->after_suspend = HI3110_AFTER_SUSPEND_RESTART;398		queue_work(priv->wq, &priv->restart_work);399		break;400	default:401		return -EOPNOTSUPP;402	}403 404	return 0;405}406 407static int hi3110_get_berr_counter(const struct net_device *net,408				   struct can_berr_counter *bec)409{410	struct hi3110_priv *priv = netdev_priv(net);411	struct spi_device *spi = priv->spi;412 413	mutex_lock(&priv->hi3110_lock);414	bec->txerr = hi3110_read(spi, HI3110_READ_TEC);415	bec->rxerr = hi3110_read(spi, HI3110_READ_REC);416	mutex_unlock(&priv->hi3110_lock);417 418	return 0;419}420 421static int hi3110_set_normal_mode(struct spi_device *spi)422{423	struct hi3110_priv *priv = spi_get_drvdata(spi);424	u8 reg = 0;425 426	hi3110_write(spi, HI3110_WRITE_INTE, HI3110_INT_BUSERR |427		     HI3110_INT_RXFIFO | HI3110_INT_TXCPLT);428 429	/* Enable TX */430	hi3110_write(spi, HI3110_WRITE_CTRL1, HI3110_CTRL1_TXEN);431 432	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)433		reg = HI3110_CTRL0_LOOPBACK_MODE;434	else if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)435		reg = HI3110_CTRL0_MONITOR_MODE;436	else437		reg = HI3110_CTRL0_NORMAL_MODE;438 439	hi3110_write(spi, HI3110_WRITE_CTRL0, reg);440 441	/* Wait for the device to enter the mode */442	mdelay(HI3110_OST_DELAY_MS);443	reg = hi3110_read(spi, HI3110_READ_CTRL0);444	if ((reg & HI3110_CTRL0_MODE_MASK) != reg)445		return -EBUSY;446 447	priv->can.state = CAN_STATE_ERROR_ACTIVE;448	return 0;449}450 451static int hi3110_do_set_bittiming(struct net_device *net)452{453	struct hi3110_priv *priv = netdev_priv(net);454	struct can_bittiming *bt = &priv->can.bittiming;455	struct spi_device *spi = priv->spi;456 457	hi3110_write(spi, HI3110_WRITE_BTR0,458		     ((bt->sjw - 1) << HI3110_BTR0_SJW_SHIFT) |459		     ((bt->brp - 1) << HI3110_BTR0_BRP_SHIFT));460 461	hi3110_write(spi, HI3110_WRITE_BTR1,462		     (priv->can.ctrlmode &463		      CAN_CTRLMODE_3_SAMPLES ?464		      HI3110_BTR1_SAMP_3PERBIT : HI3110_BTR1_SAMP_1PERBIT) |465		     ((bt->phase_seg1 + bt->prop_seg - 1)466		      << HI3110_BTR1_TSEG1_SHIFT) |467		     ((bt->phase_seg2 - 1) << HI3110_BTR1_TSEG2_SHIFT));468 469	dev_dbg(&spi->dev, "BT: 0x%02x 0x%02x\n",470		hi3110_read(spi, HI3110_READ_BTR0),471		hi3110_read(spi, HI3110_READ_BTR1));472 473	return 0;474}475 476static int hi3110_setup(struct net_device *net)477{478	hi3110_do_set_bittiming(net);479	return 0;480}481 482static int hi3110_hw_reset(struct spi_device *spi)483{484	u8 reg;485	int ret;486 487	/* Wait for oscillator startup timer after power up */488	mdelay(HI3110_OST_DELAY_MS);489 490	ret = hi3110_cmd(spi, HI3110_MASTER_RESET);491	if (ret)492		return ret;493 494	/* Wait for oscillator startup timer after reset */495	mdelay(HI3110_OST_DELAY_MS);496 497	reg = hi3110_read(spi, HI3110_READ_CTRL0);498	if ((reg & HI3110_CTRL0_MODE_MASK) != HI3110_CTRL0_INIT_MODE)499		return -ENODEV;500 501	/* As per the datasheet it appears the error flags are502	 * not cleared on reset. Explicitly clear them by performing a read503	 */504	hi3110_read(spi, HI3110_READ_ERR);505 506	return 0;507}508 509static int hi3110_hw_probe(struct spi_device *spi)510{511	u8 statf;512 513	hi3110_hw_reset(spi);514 515	/* Confirm correct operation by checking against reset values516	 * in datasheet517	 */518	statf = hi3110_read(spi, HI3110_READ_STATF);519 520	dev_dbg(&spi->dev, "statf: %02X\n", statf);521 522	if (statf != 0x82)523		return -ENODEV;524 525	return 0;526}527 528static int hi3110_power_enable(struct regulator *reg, int enable)529{530	if (IS_ERR_OR_NULL(reg))531		return 0;532 533	if (enable)534		return regulator_enable(reg);535	else536		return regulator_disable(reg);537}538 539static int hi3110_stop(struct net_device *net)540{541	struct hi3110_priv *priv = netdev_priv(net);542	struct spi_device *spi = priv->spi;543 544	close_candev(net);545 546	priv->force_quit = 1;547	free_irq(spi->irq, priv);548	destroy_workqueue(priv->wq);549	priv->wq = NULL;550 551	mutex_lock(&priv->hi3110_lock);552 553	/* Disable transmit, interrupts and clear flags */554	hi3110_write(spi, HI3110_WRITE_CTRL1, 0x0);555	hi3110_write(spi, HI3110_WRITE_INTE, 0x0);556	hi3110_read(spi, HI3110_READ_INTF);557 558	hi3110_clean(net);559 560	hi3110_hw_sleep(spi);561 562	hi3110_power_enable(priv->transceiver, 0);563 564	priv->can.state = CAN_STATE_STOPPED;565 566	mutex_unlock(&priv->hi3110_lock);567 568	return 0;569}570 571static void hi3110_tx_work_handler(struct work_struct *ws)572{573	struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,574						tx_work);575	struct spi_device *spi = priv->spi;576	struct net_device *net = priv->net;577	struct can_frame *frame;578 579	mutex_lock(&priv->hi3110_lock);580	if (priv->tx_skb) {581		if (priv->can.state == CAN_STATE_BUS_OFF) {582			hi3110_clean(net);583		} else {584			frame = (struct can_frame *)priv->tx_skb->data;585			hi3110_hw_tx(spi, frame);586			priv->tx_busy = true;587			can_put_echo_skb(priv->tx_skb, net, 0, 0);588			priv->tx_skb = NULL;589		}590	}591	mutex_unlock(&priv->hi3110_lock);592}593 594static void hi3110_restart_work_handler(struct work_struct *ws)595{596	struct hi3110_priv *priv = container_of(ws, struct hi3110_priv,597						restart_work);598	struct spi_device *spi = priv->spi;599	struct net_device *net = priv->net;600 601	mutex_lock(&priv->hi3110_lock);602	if (priv->after_suspend) {603		hi3110_hw_reset(spi);604		hi3110_setup(net);605		if (priv->after_suspend & HI3110_AFTER_SUSPEND_RESTART) {606			hi3110_set_normal_mode(spi);607		} else if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {608			netif_device_attach(net);609			hi3110_clean(net);610			hi3110_set_normal_mode(spi);611			netif_wake_queue(net);612		} else {613			hi3110_hw_sleep(spi);614		}615		priv->after_suspend = 0;616		priv->force_quit = 0;617	}618 619	if (priv->restart_tx) {620		priv->restart_tx = 0;621		hi3110_hw_reset(spi);622		hi3110_setup(net);623		hi3110_clean(net);624		hi3110_set_normal_mode(spi);625		netif_wake_queue(net);626	}627	mutex_unlock(&priv->hi3110_lock);628}629 630static irqreturn_t hi3110_can_ist(int irq, void *dev_id)631{632	struct hi3110_priv *priv = dev_id;633	struct spi_device *spi = priv->spi;634	struct net_device *net = priv->net;635 636	mutex_lock(&priv->hi3110_lock);637 638	while (!priv->force_quit) {639		enum can_state new_state;640		u8 intf, eflag, statf;641 642		while (!(HI3110_STAT_RXFMTY &643			 (statf = hi3110_read(spi, HI3110_READ_STATF)))) {644			hi3110_hw_rx(spi);645		}646 647		intf = hi3110_read(spi, HI3110_READ_INTF);648		eflag = hi3110_read(spi, HI3110_READ_ERR);649		/* Update can state */650		if (eflag & HI3110_ERR_BUSOFF)651			new_state = CAN_STATE_BUS_OFF;652		else if (eflag & HI3110_ERR_PASSIVE_MASK)653			new_state = CAN_STATE_ERROR_PASSIVE;654		else if (statf & HI3110_STAT_ERRW)655			new_state = CAN_STATE_ERROR_WARNING;656		else657			new_state = CAN_STATE_ERROR_ACTIVE;658 659		if (new_state != priv->can.state) {660			struct can_frame *cf;661			struct sk_buff *skb;662			enum can_state rx_state, tx_state;663			u8 rxerr, txerr;664 665			skb = alloc_can_err_skb(net, &cf);666			if (!skb)667				break;668 669			txerr = hi3110_read(spi, HI3110_READ_TEC);670			rxerr = hi3110_read(spi, HI3110_READ_REC);671			tx_state = txerr >= rxerr ? new_state : 0;672			rx_state = txerr <= rxerr ? new_state : 0;673			can_change_state(net, cf, tx_state, rx_state);674			netif_rx(skb);675 676			if (new_state == CAN_STATE_BUS_OFF) {677				can_bus_off(net);678				if (priv->can.restart_ms == 0) {679					priv->force_quit = 1;680					hi3110_hw_sleep(spi);681					break;682				}683			} else {684				cf->can_id |= CAN_ERR_CNT;685				cf->data[6] = txerr;686				cf->data[7] = rxerr;687			}688		}689 690		/* Update bus errors */691		if ((intf & HI3110_INT_BUSERR) &&692		    (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)) {693			struct can_frame *cf;694			struct sk_buff *skb;695 696			/* Check for protocol errors */697			if (eflag & HI3110_ERR_PROTOCOL_MASK) {698				skb = alloc_can_err_skb(net, &cf);699				if (!skb)700					break;701 702				cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;703				priv->can.can_stats.bus_error++;704				priv->net->stats.rx_errors++;705				if (eflag & HI3110_ERR_BITERR)706					cf->data[2] |= CAN_ERR_PROT_BIT;707				else if (eflag & HI3110_ERR_FRMERR)708					cf->data[2] |= CAN_ERR_PROT_FORM;709				else if (eflag & HI3110_ERR_STUFERR)710					cf->data[2] |= CAN_ERR_PROT_STUFF;711				else if (eflag & HI3110_ERR_CRCERR)712					cf->data[3] |= CAN_ERR_PROT_LOC_CRC_SEQ;713				else if (eflag & HI3110_ERR_ACKERR)714					cf->data[3] |= CAN_ERR_PROT_LOC_ACK;715 716				cf->data[6] = hi3110_read(spi, HI3110_READ_TEC);717				cf->data[7] = hi3110_read(spi, HI3110_READ_REC);718				netdev_dbg(priv->net, "Bus Error\n");719				netif_rx(skb);720			}721		}722 723		if (priv->tx_busy && statf & HI3110_STAT_TXMTY) {724			net->stats.tx_packets++;725			net->stats.tx_bytes += can_get_echo_skb(net, 0, NULL);726			priv->tx_busy = false;727			netif_wake_queue(net);728		}729 730		if (intf == 0)731			break;732	}733	mutex_unlock(&priv->hi3110_lock);734	return IRQ_HANDLED;735}736 737static int hi3110_open(struct net_device *net)738{739	struct hi3110_priv *priv = netdev_priv(net);740	struct spi_device *spi = priv->spi;741	unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_HIGH;742	int ret;743 744	ret = open_candev(net);745	if (ret)746		return ret;747 748	mutex_lock(&priv->hi3110_lock);749	hi3110_power_enable(priv->transceiver, 1);750 751	priv->force_quit = 0;752	priv->tx_skb = NULL;753	priv->tx_busy = false;754 755	ret = request_threaded_irq(spi->irq, NULL, hi3110_can_ist,756				   flags, DEVICE_NAME, priv);757	if (ret) {758		dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);759		goto out_close;760	}761 762	priv->wq = alloc_workqueue("hi3110_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,763				   0);764	if (!priv->wq) {765		ret = -ENOMEM;766		goto out_free_irq;767	}768	INIT_WORK(&priv->tx_work, hi3110_tx_work_handler);769	INIT_WORK(&priv->restart_work, hi3110_restart_work_handler);770 771	ret = hi3110_hw_reset(spi);772	if (ret)773		goto out_free_wq;774 775	ret = hi3110_setup(net);776	if (ret)777		goto out_free_wq;778 779	ret = hi3110_set_normal_mode(spi);780	if (ret)781		goto out_free_wq;782 783	netif_wake_queue(net);784	mutex_unlock(&priv->hi3110_lock);785 786	return 0;787 788 out_free_wq:789	destroy_workqueue(priv->wq);790 out_free_irq:791	free_irq(spi->irq, priv);792	hi3110_hw_sleep(spi);793 out_close:794	hi3110_power_enable(priv->transceiver, 0);795	close_candev(net);796	mutex_unlock(&priv->hi3110_lock);797	return ret;798}799 800static const struct net_device_ops hi3110_netdev_ops = {801	.ndo_open = hi3110_open,802	.ndo_stop = hi3110_stop,803	.ndo_start_xmit = hi3110_hard_start_xmit,804};805 806static const struct ethtool_ops hi3110_ethtool_ops = {807	.get_ts_info = ethtool_op_get_ts_info,808};809 810static const struct of_device_id hi3110_of_match[] = {811	{812		.compatible	= "holt,hi3110",813		.data		= (void *)CAN_HI3110_HI3110,814	},815	{ }816};817MODULE_DEVICE_TABLE(of, hi3110_of_match);818 819static const struct spi_device_id hi3110_id_table[] = {820	{821		.name		= "hi3110",822		.driver_data	= (kernel_ulong_t)CAN_HI3110_HI3110,823	},824	{ }825};826MODULE_DEVICE_TABLE(spi, hi3110_id_table);827 828static int hi3110_can_probe(struct spi_device *spi)829{830	struct device *dev = &spi->dev;831	struct net_device *net;832	struct hi3110_priv *priv;833	struct clk *clk;834	u32 freq;835	int ret;836 837	clk = devm_clk_get_optional(&spi->dev, NULL);838	if (IS_ERR(clk))839		return dev_err_probe(dev, PTR_ERR(clk), "no CAN clock source defined\n");840 841	if (clk) {842		freq = clk_get_rate(clk);843	} else {844		ret = device_property_read_u32(dev, "clock-frequency", &freq);845		if (ret)846			return dev_err_probe(dev, ret, "Failed to get clock-frequency!\n");847	}848 849	/* Sanity check */850	if (freq > 40000000)851		return -ERANGE;852 853	/* Allocate can/net device */854	net = alloc_candev(sizeof(struct hi3110_priv), HI3110_TX_ECHO_SKB_MAX);855	if (!net)856		return -ENOMEM;857 858	ret = clk_prepare_enable(clk);859	if (ret)860		goto out_free;861 862	net->netdev_ops = &hi3110_netdev_ops;863	net->ethtool_ops = &hi3110_ethtool_ops;864	net->flags |= IFF_ECHO;865 866	priv = netdev_priv(net);867	priv->can.bittiming_const = &hi3110_bittiming_const;868	priv->can.do_set_mode = hi3110_do_set_mode;869	priv->can.do_get_berr_counter = hi3110_get_berr_counter;870	priv->can.clock.freq = freq / 2;871	priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |872		CAN_CTRLMODE_LOOPBACK |873		CAN_CTRLMODE_LISTENONLY |874		CAN_CTRLMODE_BERR_REPORTING;875 876	priv->model = (enum hi3110_model)(uintptr_t)spi_get_device_match_data(spi);877	priv->net = net;878	priv->clk = clk;879 880	spi_set_drvdata(spi, priv);881 882	/* Configure the SPI bus */883	spi->bits_per_word = 8;884	ret = spi_setup(spi);885	if (ret)886		goto out_clk;887 888	priv->power = devm_regulator_get_optional(&spi->dev, "vdd");889	priv->transceiver = devm_regulator_get_optional(&spi->dev, "xceiver");890	if ((PTR_ERR(priv->power) == -EPROBE_DEFER) ||891	    (PTR_ERR(priv->transceiver) == -EPROBE_DEFER)) {892		ret = -EPROBE_DEFER;893		goto out_clk;894	}895 896	ret = hi3110_power_enable(priv->power, 1);897	if (ret)898		goto out_clk;899 900	priv->spi = spi;901	mutex_init(&priv->hi3110_lock);902 903	priv->spi_tx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,904					GFP_KERNEL);905	if (!priv->spi_tx_buf) {906		ret = -ENOMEM;907		goto error_probe;908	}909	priv->spi_rx_buf = devm_kzalloc(&spi->dev, HI3110_RX_BUF_LEN,910					GFP_KERNEL);911 912	if (!priv->spi_rx_buf) {913		ret = -ENOMEM;914		goto error_probe;915	}916 917	SET_NETDEV_DEV(net, &spi->dev);918 919	ret = hi3110_hw_probe(spi);920	if (ret) {921		dev_err_probe(dev, ret, "Cannot initialize %x. Wrong wiring?\n", priv->model);922		goto error_probe;923	}924	hi3110_hw_sleep(spi);925 926	ret = register_candev(net);927	if (ret)928		goto error_probe;929 930	netdev_info(net, "%x successfully initialized.\n", priv->model);931 932	return 0;933 934 error_probe:935	hi3110_power_enable(priv->power, 0);936 937 out_clk:938	clk_disable_unprepare(clk);939 940 out_free:941	free_candev(net);942 943	return dev_err_probe(dev, ret, "Probe failed\n");944}945 946static void hi3110_can_remove(struct spi_device *spi)947{948	struct hi3110_priv *priv = spi_get_drvdata(spi);949	struct net_device *net = priv->net;950 951	unregister_candev(net);952 953	hi3110_power_enable(priv->power, 0);954 955	clk_disable_unprepare(priv->clk);956 957	free_candev(net);958}959 960static int __maybe_unused hi3110_can_suspend(struct device *dev)961{962	struct spi_device *spi = to_spi_device(dev);963	struct hi3110_priv *priv = spi_get_drvdata(spi);964	struct net_device *net = priv->net;965 966	priv->force_quit = 1;967	disable_irq(spi->irq);968 969	/* Note: at this point neither IST nor workqueues are running.970	 * open/stop cannot be called anyway so locking is not needed971	 */972	if (netif_running(net)) {973		netif_device_detach(net);974 975		hi3110_hw_sleep(spi);976		hi3110_power_enable(priv->transceiver, 0);977		priv->after_suspend = HI3110_AFTER_SUSPEND_UP;978	} else {979		priv->after_suspend = HI3110_AFTER_SUSPEND_DOWN;980	}981 982	if (!IS_ERR_OR_NULL(priv->power)) {983		regulator_disable(priv->power);984		priv->after_suspend |= HI3110_AFTER_SUSPEND_POWER;985	}986 987	return 0;988}989 990static int __maybe_unused hi3110_can_resume(struct device *dev)991{992	struct spi_device *spi = to_spi_device(dev);993	struct hi3110_priv *priv = spi_get_drvdata(spi);994 995	if (priv->after_suspend & HI3110_AFTER_SUSPEND_POWER)996		hi3110_power_enable(priv->power, 1);997 998	if (priv->after_suspend & HI3110_AFTER_SUSPEND_UP) {999		hi3110_power_enable(priv->transceiver, 1);1000		queue_work(priv->wq, &priv->restart_work);1001	} else {1002		priv->after_suspend = 0;1003	}1004 1005	priv->force_quit = 0;1006	enable_irq(spi->irq);1007	return 0;1008}1009 1010static SIMPLE_DEV_PM_OPS(hi3110_can_pm_ops, hi3110_can_suspend, hi3110_can_resume);1011 1012static struct spi_driver hi3110_can_driver = {1013	.driver = {1014		.name = DEVICE_NAME,1015		.of_match_table = hi3110_of_match,1016		.pm = &hi3110_can_pm_ops,1017	},1018	.id_table = hi3110_id_table,1019	.probe = hi3110_can_probe,1020	.remove = hi3110_can_remove,1021};1022 1023module_spi_driver(hi3110_can_driver);1024 1025MODULE_AUTHOR("Akshay Bhat <akshay.bhat@timesys.com>");1026MODULE_AUTHOR("Casey Fitzpatrick <casey.fitzpatrick@timesys.com>");1027MODULE_DESCRIPTION("Holt HI-3110 CAN driver");1028MODULE_LICENSE("GPL v2");1029