[mirror_ubuntu-bionic-kernel.git] / drivers / net / can / sja1000 / sja1000.c

/*
 * sja1000.c -  Philips SJA1000 network device driver
 *
 * Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
 * 38106 Braunschweig, GERMANY
 *
 * Copyright (c) 2002-2007 Volkswagen Group Electronic Research
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Volkswagen nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * Alternatively, provided that this notice is retained in full, this
 * software may be distributed under the terms of the GNU General
 * Public License ("GPL") version 2, in which case the provisions of the
 * GPL apply INSTEAD OF those given above.
 *
 * The provided data structures and external interfaces from this code
 * are not restricted to be used by modules with a GPL compatible license.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
 * DAMAGE.
 *
 * Send feedback to <socketcan-users@lists.berlios.de>
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/if_ether.h>
#include <linux/skbuff.h>
#include <linux/delay.h>

#include <linux/can.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <linux/can/dev.h>

#include "sja1000.h"

#define DRV_NAME "sja1000"

MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");

static struct can_bittiming_const sja1000_bittiming_const = {
	.name = DRV_NAME,
	.tseg1_min = 1,
	.tseg1_max = 16,
	.tseg2_min = 1,
	.tseg2_max = 8,
	.sjw_max = 4,
	.brp_min = 1,
	.brp_max = 64,
	.brp_inc = 1,
};

static int sja1000_probe_chip(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
		printk(KERN_INFO "%s: probing @0x%lX failed\n",
		       DRV_NAME, dev->base_addr);
		return 0;
	}
	return -1;
}

static void set_reset_mode(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	unsigned char status = priv->read_reg(priv, REG_MOD);
	int i;

	/* disable interrupts */
	priv->write_reg(priv, REG_IER, IRQ_OFF);

	for (i = 0; i < 100; i++) {
		/* check reset bit */
		if (status & MOD_RM) {
			priv->can.state = CAN_STATE_STOPPED;
			return;
		}

		priv->write_reg(priv, REG_MOD, MOD_RM);	/* reset chip */
		udelay(10);
		status = priv->read_reg(priv, REG_MOD);
	}

	dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n");
}

static void set_normal_mode(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	unsigned char status = priv->read_reg(priv, REG_MOD);
	int i;

	for (i = 0; i < 100; i++) {
		/* check reset bit */
		if ((status & MOD_RM) == 0) {
			priv->can.state = CAN_STATE_ERROR_ACTIVE;
			/* enable all interrupts */
			priv->write_reg(priv, REG_IER, IRQ_ALL);
			return;
		}

		/* set chip to normal mode */
		priv->write_reg(priv, REG_MOD, 0x00);
		udelay(10);
		status = priv->read_reg(priv, REG_MOD);
	}

	dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
}

static void sja1000_start(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	/* leave reset mode */
	if (priv->can.state != CAN_STATE_STOPPED)
		set_reset_mode(dev);

	/* Clear error counters and error code capture */
	priv->write_reg(priv, REG_TXERR, 0x0);
	priv->write_reg(priv, REG_RXERR, 0x0);
	priv->read_reg(priv, REG_ECC);

	/* leave reset mode */
	set_normal_mode(dev);
}

static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	if (!priv->open_time)
		return -EINVAL;

	switch (mode) {
	case CAN_MODE_START:
		sja1000_start(dev);
		if (netif_queue_stopped(dev))
			netif_wake_queue(dev);
		break;

	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int sja1000_set_bittiming(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct can_bittiming *bt = &priv->can.bittiming;
	u8 btr0, btr1;

	btr0 = ((bt->brp - 1) & 0x3f) | (((bt->sjw - 1) & 0x3) << 6);
	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) |
		(((bt->phase_seg2 - 1) & 0x7) << 4);
	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
		btr1 |= 0x80;

	dev_info(dev->dev.parent,
		 "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);

	priv->write_reg(priv, REG_BTR0, btr0);
	priv->write_reg(priv, REG_BTR1, btr1);

	return 0;
}

/*
 * initialize SJA1000 chip:
 *   - reset chip
 *   - set output mode
 *   - set baudrate
 *   - enable interrupts
 *   - start operating mode
 */
static void chipset_init(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	/* set clock divider and output control register */
	priv->write_reg(priv, REG_CDR, priv->cdr | CDR_PELICAN);

	/* set acceptance filter (accept all) */
	priv->write_reg(priv, REG_ACCC0, 0x00);
	priv->write_reg(priv, REG_ACCC1, 0x00);
	priv->write_reg(priv, REG_ACCC2, 0x00);
	priv->write_reg(priv, REG_ACCC3, 0x00);

	priv->write_reg(priv, REG_ACCM0, 0xFF);
	priv->write_reg(priv, REG_ACCM1, 0xFF);
	priv->write_reg(priv, REG_ACCM2, 0xFF);
	priv->write_reg(priv, REG_ACCM3, 0xFF);

	priv->write_reg(priv, REG_OCR, priv->ocr | OCR_MODE_NORMAL);
}

/*
 * transmit a CAN message
 * message layout in the sk_buff should be like this:
 * xx xx xx xx	 ff	 ll   00 11 22 33 44 55 66 77
 * [  can-id ] [flags] [len] [can data (up to 8 bytes]
 */
static int sja1000_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf = (struct can_frame *)skb->data;
	uint8_t fi;
	uint8_t dlc;
	canid_t id;
	uint8_t dreg;
	int i;

	netif_stop_queue(dev);

	fi = dlc = cf->can_dlc;
	id = cf->can_id;

	if (id & CAN_RTR_FLAG)
		fi |= FI_RTR;

	if (id & CAN_EFF_FLAG) {
		fi |= FI_FF;
		dreg = EFF_BUF;
		priv->write_reg(priv, REG_FI, fi);
		priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
		priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
		priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
		priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
	} else {
		dreg = SFF_BUF;
		priv->write_reg(priv, REG_FI, fi);
		priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
		priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
	}

	for (i = 0; i < dlc; i++)
		priv->write_reg(priv, dreg++, cf->data[i]);

	stats->tx_bytes += dlc;
	dev->trans_start = jiffies;

	can_put_echo_skb(skb, dev, 0);

	priv->write_reg(priv, REG_CMR, CMD_TR);

	return NETDEV_TX_OK;
}

static void sja1000_rx(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	uint8_t fi;
	uint8_t dreg;
	canid_t id;
	uint8_t dlc;
	int i;

	skb = dev_alloc_skb(sizeof(struct can_frame));
	if (skb == NULL)
		return;
	skb->dev = dev;
	skb->protocol = htons(ETH_P_CAN);

	fi = priv->read_reg(priv, REG_FI);
	dlc = fi & 0x0F;

	if (fi & FI_FF) {
		/* extended frame format (EFF) */
		dreg = EFF_BUF;
		id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
		    | (priv->read_reg(priv, REG_ID2) << (5 + 8))
		    | (priv->read_reg(priv, REG_ID3) << 5)
		    | (priv->read_reg(priv, REG_ID4) >> 3);
		id |= CAN_EFF_FLAG;
	} else {
		/* standard frame format (SFF) */
		dreg = SFF_BUF;
		id = (priv->read_reg(priv, REG_ID1) << 3)
		    | (priv->read_reg(priv, REG_ID2) >> 5);
	}

	if (fi & FI_RTR)
		id |= CAN_RTR_FLAG;

	cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
	memset(cf, 0, sizeof(struct can_frame));
	cf->can_id = id;
	cf->can_dlc = dlc;
	for (i = 0; i < dlc; i++)
		cf->data[i] = priv->read_reg(priv, dreg++);

	while (i < 8)
		cf->data[i++] = 0;

	/* release receive buffer */
	priv->write_reg(priv, REG_CMR, CMD_RRB);

	netif_rx(skb);

	dev->last_rx = jiffies;
	stats->rx_packets++;
	stats->rx_bytes += dlc;
}

static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	struct can_frame *cf;
	struct sk_buff *skb;
	enum can_state state = priv->can.state;
	uint8_t ecc, alc;

	skb = dev_alloc_skb(sizeof(struct can_frame));
	if (skb == NULL)
		return -ENOMEM;
	skb->dev = dev;
	skb->protocol = htons(ETH_P_CAN);
	cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
	memset(cf, 0, sizeof(struct can_frame));
	cf->can_id = CAN_ERR_FLAG;
	cf->can_dlc = CAN_ERR_DLC;

	if (isrc & IRQ_DOI) {
		/* data overrun interrupt */
		dev_dbg(dev->dev.parent, "data overrun interrupt\n");
		cf->can_id |= CAN_ERR_CRTL;
		cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
		stats->rx_over_errors++;
		stats->rx_errors++;
		priv->write_reg(priv, REG_CMR, CMD_CDO);	/* clear bit */
	}

	if (isrc & IRQ_EI) {
		/* error warning interrupt */
		dev_dbg(dev->dev.parent, "error warning interrupt\n");

		if (status & SR_BS) {
			state = CAN_STATE_BUS_OFF;
			cf->can_id |= CAN_ERR_BUSOFF;
			can_bus_off(dev);
		} else if (status & SR_ES) {
			state = CAN_STATE_ERROR_WARNING;
		} else
			state = CAN_STATE_ERROR_ACTIVE;
	}
	if (isrc & IRQ_BEI) {
		/* bus error interrupt */
		priv->can.can_stats.bus_error++;
		stats->rx_errors++;

		ecc = priv->read_reg(priv, REG_ECC);

		cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;

		switch (ecc & ECC_MASK) {
		case ECC_BIT:
			cf->data[2] |= CAN_ERR_PROT_BIT;
			break;
		case ECC_FORM:
			cf->data[2] |= CAN_ERR_PROT_FORM;
			break;
		case ECC_STUFF:
			cf->data[2] |= CAN_ERR_PROT_STUFF;
			break;
		default:
			cf->data[2] |= CAN_ERR_PROT_UNSPEC;
			cf->data[3] = ecc & ECC_SEG;
			break;
		}
		/* Error occured during transmission? */
		if ((ecc & ECC_DIR) == 0)
			cf->data[2] |= CAN_ERR_PROT_TX;
	}
	if (isrc & IRQ_EPI) {
		/* error passive interrupt */
		dev_dbg(dev->dev.parent, "error passive interrupt\n");
		if (status & SR_ES)
			state = CAN_STATE_ERROR_PASSIVE;
		else
			state = CAN_STATE_ERROR_ACTIVE;
	}
	if (isrc & IRQ_ALI) {
		/* arbitration lost interrupt */
		dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
		alc = priv->read_reg(priv, REG_ALC);
		priv->can.can_stats.arbitration_lost++;
		stats->rx_errors++;
		cf->can_id |= CAN_ERR_LOSTARB;
		cf->data[0] = alc & 0x1f;
	}

	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
					 state == CAN_STATE_ERROR_PASSIVE)) {
		uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
		uint8_t txerr = priv->read_reg(priv, REG_TXERR);
		cf->can_id |= CAN_ERR_CRTL;
		if (state == CAN_STATE_ERROR_WARNING) {
			priv->can.can_stats.error_warning++;
			cf->data[1] = (txerr > rxerr) ?
				CAN_ERR_CRTL_TX_WARNING :
				CAN_ERR_CRTL_RX_WARNING;
		} else {
			priv->can.can_stats.error_passive++;
			cf->data[1] = (txerr > rxerr) ?
				CAN_ERR_CRTL_TX_PASSIVE :
				CAN_ERR_CRTL_RX_PASSIVE;
		}
	}

	priv->can.state = state;

	netif_rx(skb);

	dev->last_rx = jiffies;
	stats->rx_packets++;
	stats->rx_bytes += cf->can_dlc;

	return 0;
}

irqreturn_t sja1000_interrupt(int irq, void *dev_id)
{
	struct net_device *dev = (struct net_device *)dev_id;
	struct sja1000_priv *priv = netdev_priv(dev);
	struct net_device_stats *stats = &dev->stats;
	uint8_t isrc, status;
	int n = 0;

	/* Shared interrupts and IRQ off? */
	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
		return IRQ_NONE;

	if (priv->pre_irq)
		priv->pre_irq(priv);

	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
		n++;
		status = priv->read_reg(priv, REG_SR);

		if (isrc & IRQ_WUI)
			dev_warn(dev->dev.parent, "wakeup interrupt\n");

		if (isrc & IRQ_TI) {
			/* transmission complete interrupt */
			stats->tx_packets++;
			can_get_echo_skb(dev, 0);
			netif_wake_queue(dev);
		}
		if (isrc & IRQ_RI) {
			/* receive interrupt */
			while (status & SR_RBS) {
				sja1000_rx(dev);
				status = priv->read_reg(priv, REG_SR);
			}
		}
		if (isrc & (IRQ_DOI | IRQ_EI | IRQ_BEI | IRQ_EPI | IRQ_ALI)) {
			/* error interrupt */
			if (sja1000_err(dev, isrc, status))
				break;
		}
	}

	if (priv->post_irq)
		priv->post_irq(priv);

	if (n >= SJA1000_MAX_IRQ)
		dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);

	return (n) ? IRQ_HANDLED : IRQ_NONE;
}
EXPORT_SYMBOL_GPL(sja1000_interrupt);

static int sja1000_open(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);
	int err;

	/* set chip into reset mode */
	set_reset_mode(dev);

	/* common open */
	err = open_candev(dev);
	if (err)
		return err;

	/* register interrupt handler, if not done by the device driver */
	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
		err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags,
				  dev->name, (void *)dev);
		if (err) {
			close_candev(dev);
			return -EAGAIN;
		}
	}

	/* init and start chi */
	sja1000_start(dev);
	priv->open_time = jiffies;

	netif_start_queue(dev);

	return 0;
}

static int sja1000_close(struct net_device *dev)
{
	struct sja1000_priv *priv = netdev_priv(dev);

	netif_stop_queue(dev);
	set_reset_mode(dev);

	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
		free_irq(dev->irq, (void *)dev);

	close_candev(dev);

	priv->open_time = 0;

	return 0;
}

struct net_device *alloc_sja1000dev(int sizeof_priv)
{
	struct net_device *dev;
	struct sja1000_priv *priv;

	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv);
	if (!dev)
		return NULL;

	priv = netdev_priv(dev);

	priv->dev = dev;
	priv->can.bittiming_const = &sja1000_bittiming_const;
	priv->can.do_set_bittiming = sja1000_set_bittiming;
	priv->can.do_set_mode = sja1000_set_mode;

	if (sizeof_priv)
		priv->priv = (void *)priv + sizeof(struct sja1000_priv);

	return dev;
}
EXPORT_SYMBOL_GPL(alloc_sja1000dev);

void free_sja1000dev(struct net_device *dev)
{
	free_candev(dev);
}
EXPORT_SYMBOL_GPL(free_sja1000dev);

static const struct net_device_ops sja1000_netdev_ops = {
       .ndo_open               = sja1000_open,
       .ndo_stop               = sja1000_close,
       .ndo_start_xmit         = sja1000_start_xmit,
};

int register_sja1000dev(struct net_device *dev)
{
	if (!sja1000_probe_chip(dev))
		return -ENODEV;

	dev->flags |= IFF_ECHO;	/* we support local echo */
	dev->netdev_ops = &sja1000_netdev_ops;

	set_reset_mode(dev);
	chipset_init(dev);

	return register_candev(dev);
}
EXPORT_SYMBOL_GPL(register_sja1000dev);

void unregister_sja1000dev(struct net_device *dev)
{
	set_reset_mode(dev);
	unregister_candev(dev);
}
EXPORT_SYMBOL_GPL(unregister_sja1000dev);

static __init int sja1000_init(void)
{
	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);

	return 0;
}

module_init(sja1000_init);

static __exit void sja1000_exit(void)
{
	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
}

module_exit(sja1000_exit);
Commit	Line	Data
429da1cc WG	1	/*
	2	* sja1000.c - Philips SJA1000 network device driver
	3	*
	4	* Copyright (c) 2003 Matthias Brukner, Trajet Gmbh, Rebenring 33,
	5	* 38106 Braunschweig, GERMANY
	6	*
	7	* Copyright (c) 2002-2007 Volkswagen Group Electronic Research
	8	* All rights reserved.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. Neither the name of Volkswagen nor the names of its contributors
	19	* may be used to endorse or promote products derived from this software
	20	* without specific prior written permission.
	21	*
	22	* Alternatively, provided that this notice is retained in full, this
	23	* software may be distributed under the terms of the GNU General
	24	* Public License ("GPL") version 2, in which case the provisions of the
	25	* GPL apply INSTEAD OF those given above.
	26	*
	27	* The provided data structures and external interfaces from this code
	28	* are not restricted to be used by modules with a GPL compatible license.
	29	*
	30	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	31	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	32	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	33	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	34	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	35	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	36	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	37	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	38	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	39	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	40	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
	41	* DAMAGE.
	42	*
	43	* Send feedback to <socketcan-users@lists.berlios.de>
	44	*
	45	*/
	46
	47	#include <linux/module.h>
	48	#include <linux/init.h>
	49	#include <linux/kernel.h>
	50	#include <linux/sched.h>
	51	#include <linux/types.h>
	52	#include <linux/fcntl.h>
	53	#include <linux/interrupt.h>
	54	#include <linux/ptrace.h>
	55	#include <linux/string.h>
	56	#include <linux/errno.h>
	57	#include <linux/netdevice.h>
	58	#include <linux/if_arp.h>
	59	#include <linux/if_ether.h>
	60	#include <linux/skbuff.h>
	61	#include <linux/delay.h>
	62
	63	#include <linux/can.h>
	64	#include <linux/can/dev.h>
65	#include <linux/can/error.h>
66	#include <linux/can/dev.h>
67
68	#include "sja1000.h"
69
70	#define DRV_NAME "sja1000"
71
72	MODULE_AUTHOR("Oliver Hartkopp <oliver.hartkopp@volkswagen.de>");
73	MODULE_LICENSE("Dual BSD/GPL");
74	MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
75
76	static struct can_bittiming_const sja1000_bittiming_const = {
77	.name = DRV_NAME,
78	.tseg1_min = 1,
79	.tseg1_max = 16,
80	.tseg2_min = 1,
81	.tseg2_max = 8,
82	.sjw_max = 4,
83	.brp_min = 1,
84	.brp_max = 64,
85	.brp_inc = 1,
86	};
87
88	static int sja1000_probe_chip(struct net_device *dev)
89	{
90	struct sja1000_priv *priv = netdev_priv(dev);
91
255a9154	92	if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
429da1cc WG	93	printk(KERN_INFO "%s: probing @0x%lX failed\n",
	94	DRV_NAME, dev->base_addr);
	95	return 0;
	96	}
	97	return -1;
	98	}
	99
	100	static void set_reset_mode(struct net_device *dev)
	101	{
	102	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	103	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	104	int i;
	105
	106	/* disable interrupts */
255a9154	107	priv->write_reg(priv, REG_IER, IRQ_OFF);
429da1cc WG	108
	109	for (i = 0; i < 100; i++) {
	110	/* check reset bit */
	111	if (status & MOD_RM) {
	112	priv->can.state = CAN_STATE_STOPPED;
	113	return;
	114	}
	115
255a9154	116	priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */
429da1cc	117	udelay(10);
255a9154	118	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	119	}
	120
	121	dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n");
	122	}
	123
	124	static void set_normal_mode(struct net_device *dev)
	125	{
	126	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	127	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	128	int i;
	129
	130	for (i = 0; i < 100; i++) {
	131	/* check reset bit */
	132	if ((status & MOD_RM) == 0) {
	133	priv->can.state = CAN_STATE_ERROR_ACTIVE;
	134	/* enable all interrupts */
255a9154	135	priv->write_reg(priv, REG_IER, IRQ_ALL);
429da1cc WG	136	return;
	137	}
	138
	139	/* set chip to normal mode */
255a9154	140	priv->write_reg(priv, REG_MOD, 0x00);
429da1cc	141	udelay(10);
255a9154	142	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	143	}
	144
	145	dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
	146	}
	147
	148	static void sja1000_start(struct net_device *dev)
	149	{
	150	struct sja1000_priv *priv = netdev_priv(dev);
	151
	152	/* leave reset mode */
	153	if (priv->can.state != CAN_STATE_STOPPED)
	154	set_reset_mode(dev);
	155
	156	/* Clear error counters and error code capture */
255a9154 WG	157	priv->write_reg(priv, REG_TXERR, 0x0);
	158	priv->write_reg(priv, REG_RXERR, 0x0);
	159	priv->read_reg(priv, REG_ECC);
429da1cc WG	160
	161	/* leave reset mode */
	162	set_normal_mode(dev);
	163	}
	164
	165	static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
	166	{
	167	struct sja1000_priv *priv = netdev_priv(dev);
	168
	169	if (!priv->open_time)
	170	return -EINVAL;
	171
	172	switch (mode) {
	173	case CAN_MODE_START:
	174	sja1000_start(dev);
	175	if (netif_queue_stopped(dev))
	176	netif_wake_queue(dev);
	177	break;
	178
	179	default:
	180	return -EOPNOTSUPP;
	181	}
	182
	183	return 0;
	184	}
	185
	186	static int sja1000_set_bittiming(struct net_device *dev)
	187	{
	188	struct sja1000_priv *priv = netdev_priv(dev);
	189	struct can_bittiming *bt = &priv->can.bittiming;
	190	u8 btr0, btr1;
	191
	192	btr0 = ((bt->brp - 1) & 0x3f) \| (((bt->sjw - 1) & 0x3) << 6);
	193	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) \|
	194	(((bt->phase_seg2 - 1) & 0x7) << 4);
	195	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
	196	btr1 \|= 0x80;
	197
	198	dev_info(dev->dev.parent,
	199	"setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
	200
255a9154 WG	201	priv->write_reg(priv, REG_BTR0, btr0);
255a9154 WG	202	priv->write_reg(priv, REG_BTR1, btr1);
429da1cc WG	203
	204	return 0;
	205	}
	206
	207	/*
	208	* initialize SJA1000 chip:
	209	* - reset chip
	210	* - set output mode
	211	* - set baudrate
	212	* - enable interrupts
	213	* - start operating mode
	214	*/
	215	static void chipset_init(struct net_device *dev)
	216	{
	217	struct sja1000_priv *priv = netdev_priv(dev);
	218
	219	/* set clock divider and output control register */
255a9154	220	priv->write_reg(priv, REG_CDR, priv->cdr \| CDR_PELICAN);
429da1cc WG	221
429da1cc WG	222	/* set acceptance filter (accept all) */
255a9154 WG	223	priv->write_reg(priv, REG_ACCC0, 0x00);
	224	priv->write_reg(priv, REG_ACCC1, 0x00);
	225	priv->write_reg(priv, REG_ACCC2, 0x00);
	226	priv->write_reg(priv, REG_ACCC3, 0x00);
429da1cc	227
255a9154 WG	228	priv->write_reg(priv, REG_ACCM0, 0xFF);
	229	priv->write_reg(priv, REG_ACCM1, 0xFF);
	230	priv->write_reg(priv, REG_ACCM2, 0xFF);
	231	priv->write_reg(priv, REG_ACCM3, 0xFF);
429da1cc	232
255a9154	233	priv->write_reg(priv, REG_OCR, priv->ocr \| OCR_MODE_NORMAL);
429da1cc WG	234	}
	235
	236	/*
	237	* transmit a CAN message
	238	* message layout in the sk_buff should be like this:
	239	* xx xx xx xx ff ll 00 11 22 33 44 55 66 77
	240	* [ can-id ] [flags] [len] [can data (up to 8 bytes]
	241	*/
	242	static int sja1000_start_xmit(struct sk_buff skb, struct net_device dev)
	243	{
	244	struct sja1000_priv *priv = netdev_priv(dev);
	245	struct net_device_stats *stats = &dev->stats;
	246	struct can_frame cf = (struct can_frame )skb->data;
	247	uint8_t fi;
	248	uint8_t dlc;
	249	canid_t id;
	250	uint8_t dreg;
	251	int i;
	252
	253	netif_stop_queue(dev);
	254
	255	fi = dlc = cf->can_dlc;
	256	id = cf->can_id;
	257
	258	if (id & CAN_RTR_FLAG)
	259	fi \|= FI_RTR;
	260
	261	if (id & CAN_EFF_FLAG) {
	262	fi \|= FI_FF;
	263	dreg = EFF_BUF;
255a9154 WG	264	priv->write_reg(priv, REG_FI, fi);
	265	priv->write_reg(priv, REG_ID1, (id & 0x1fe00000) >> (5 + 16));
	266	priv->write_reg(priv, REG_ID2, (id & 0x001fe000) >> (5 + 8));
	267	priv->write_reg(priv, REG_ID3, (id & 0x00001fe0) >> 5);
	268	priv->write_reg(priv, REG_ID4, (id & 0x0000001f) << 3);
429da1cc WG	269	} else {
429da1cc WG	270	dreg = SFF_BUF;
255a9154 WG	271	priv->write_reg(priv, REG_FI, fi);
	272	priv->write_reg(priv, REG_ID1, (id & 0x000007f8) >> 3);
	273	priv->write_reg(priv, REG_ID2, (id & 0x00000007) << 5);
429da1cc WG	274	}
	275
	276	for (i = 0; i < dlc; i++)
255a9154	277	priv->write_reg(priv, dreg++, cf->data[i]);
429da1cc WG	278
	279	stats->tx_bytes += dlc;
	280	dev->trans_start = jiffies;
	281
	282	can_put_echo_skb(skb, dev, 0);
	283
255a9154	284	priv->write_reg(priv, REG_CMR, CMD_TR);
429da1cc	285
6ed10654	286	return NETDEV_TX_OK;
429da1cc WG	287	}
	288
	289	static void sja1000_rx(struct net_device *dev)
	290	{
	291	struct sja1000_priv *priv = netdev_priv(dev);
	292	struct net_device_stats *stats = &dev->stats;
	293	struct can_frame *cf;
	294	struct sk_buff *skb;
	295	uint8_t fi;
	296	uint8_t dreg;
	297	canid_t id;
	298	uint8_t dlc;
	299	int i;
	300
	301	skb = dev_alloc_skb(sizeof(struct can_frame));
	302	if (skb == NULL)
	303	return;
	304	skb->dev = dev;
	305	skb->protocol = htons(ETH_P_CAN);
	306
255a9154	307	fi = priv->read_reg(priv, REG_FI);
429da1cc WG	308	dlc = fi & 0x0F;
	309
	310	if (fi & FI_FF) {
	311	/* extended frame format (EFF) */
	312	dreg = EFF_BUF;
255a9154 WG	313	id = (priv->read_reg(priv, REG_ID1) << (5 + 16))
	314	\| (priv->read_reg(priv, REG_ID2) << (5 + 8))
	315	\| (priv->read_reg(priv, REG_ID3) << 5)
	316	\| (priv->read_reg(priv, REG_ID4) >> 3);
429da1cc WG	317	id \|= CAN_EFF_FLAG;
	318	} else {
	319	/* standard frame format (SFF) */
	320	dreg = SFF_BUF;
255a9154 WG	321	id = (priv->read_reg(priv, REG_ID1) << 3)
255a9154 WG	322	\| (priv->read_reg(priv, REG_ID2) >> 5);
429da1cc WG	323	}
	324
	325	if (fi & FI_RTR)
	326	id \|= CAN_RTR_FLAG;
	327
	328	cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
	329	memset(cf, 0, sizeof(struct can_frame));
	330	cf->can_id = id;
	331	cf->can_dlc = dlc;
	332	for (i = 0; i < dlc; i++)
255a9154	333	cf->data[i] = priv->read_reg(priv, dreg++);
429da1cc WG	334
	335	while (i < 8)
	336	cf->data[i++] = 0;
	337
	338	/* release receive buffer */
255a9154	339	priv->write_reg(priv, REG_CMR, CMD_RRB);
429da1cc WG	340
	341	netif_rx(skb);
	342
	343	dev->last_rx = jiffies;
	344	stats->rx_packets++;
	345	stats->rx_bytes += dlc;
	346	}
	347
	348	static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
	349	{
	350	struct sja1000_priv *priv = netdev_priv(dev);
	351	struct net_device_stats *stats = &dev->stats;
	352	struct can_frame *cf;
	353	struct sk_buff *skb;
	354	enum can_state state = priv->can.state;
	355	uint8_t ecc, alc;
	356
	357	skb = dev_alloc_skb(sizeof(struct can_frame));
	358	if (skb == NULL)
	359	return -ENOMEM;
	360	skb->dev = dev;
	361	skb->protocol = htons(ETH_P_CAN);
	362	cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
	363	memset(cf, 0, sizeof(struct can_frame));
	364	cf->can_id = CAN_ERR_FLAG;
	365	cf->can_dlc = CAN_ERR_DLC;
	366
	367	if (isrc & IRQ_DOI) {
	368	/* data overrun interrupt */
	369	dev_dbg(dev->dev.parent, "data overrun interrupt\n");
	370	cf->can_id \|= CAN_ERR_CRTL;
	371	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
	372	stats->rx_over_errors++;
	373	stats->rx_errors++;
255a9154	374	priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */
429da1cc WG	375	}
	376
	377	if (isrc & IRQ_EI) {
	378	/* error warning interrupt */
	379	dev_dbg(dev->dev.parent, "error warning interrupt\n");
	380
	381	if (status & SR_BS) {
	382	state = CAN_STATE_BUS_OFF;
	383	cf->can_id \|= CAN_ERR_BUSOFF;
	384	can_bus_off(dev);
	385	} else if (status & SR_ES) {
	386	state = CAN_STATE_ERROR_WARNING;
	387	} else
	388	state = CAN_STATE_ERROR_ACTIVE;
	389	}
	390	if (isrc & IRQ_BEI) {
	391	/* bus error interrupt */
	392	priv->can.can_stats.bus_error++;
	393	stats->rx_errors++;
	394
255a9154	395	ecc = priv->read_reg(priv, REG_ECC);
429da1cc WG	396
	397	cf->can_id \|= CAN_ERR_PROT \| CAN_ERR_BUSERROR;
	398
	399	switch (ecc & ECC_MASK) {
	400	case ECC_BIT:
	401	cf->data[2] \|= CAN_ERR_PROT_BIT;
	402	break;
	403	case ECC_FORM:
	404	cf->data[2] \|= CAN_ERR_PROT_FORM;
	405	break;
	406	case ECC_STUFF:
	407	cf->data[2] \|= CAN_ERR_PROT_STUFF;
	408	break;
	409	default:
	410	cf->data[2] \|= CAN_ERR_PROT_UNSPEC;
	411	cf->data[3] = ecc & ECC_SEG;
	412	break;
	413	}
	414	/* Error occured during transmission? */
	415	if ((ecc & ECC_DIR) == 0)
	416	cf->data[2] \|= CAN_ERR_PROT_TX;
	417	}
	418	if (isrc & IRQ_EPI) {
	419	/* error passive interrupt */
	420	dev_dbg(dev->dev.parent, "error passive interrupt\n");
	421	if (status & SR_ES)
	422	state = CAN_STATE_ERROR_PASSIVE;
	423	else
	424	state = CAN_STATE_ERROR_ACTIVE;
	425	}
	426	if (isrc & IRQ_ALI) {
	427	/* arbitration lost interrupt */
	428	dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
255a9154	429	alc = priv->read_reg(priv, REG_ALC);
429da1cc WG	430	priv->can.can_stats.arbitration_lost++;
	431	stats->rx_errors++;
	432	cf->can_id \|= CAN_ERR_LOSTARB;
	433	cf->data[0] = alc & 0x1f;
	434	}
	435
	436	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING \|\|
	437	state == CAN_STATE_ERROR_PASSIVE)) {
255a9154 WG	438	uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
255a9154 WG	439	uint8_t txerr = priv->read_reg(priv, REG_TXERR);
429da1cc WG	440	cf->can_id \|= CAN_ERR_CRTL;
	441	if (state == CAN_STATE_ERROR_WARNING) {
	442	priv->can.can_stats.error_warning++;
	443	cf->data[1] = (txerr > rxerr) ?
	444	CAN_ERR_CRTL_TX_WARNING :
	445	CAN_ERR_CRTL_RX_WARNING;
	446	} else {
	447	priv->can.can_stats.error_passive++;
	448	cf->data[1] = (txerr > rxerr) ?
	449	CAN_ERR_CRTL_TX_PASSIVE :
	450	CAN_ERR_CRTL_RX_PASSIVE;
	451	}
	452	}
	453
	454	priv->can.state = state;
	455
	456	netif_rx(skb);
	457
	458	dev->last_rx = jiffies;
	459	stats->rx_packets++;
	460	stats->rx_bytes += cf->can_dlc;
	461
	462	return 0;
	463	}
	464
	465	irqreturn_t sja1000_interrupt(int irq, void *dev_id)
	466	{
	467	struct net_device dev = (struct net_device )dev_id;
	468	struct sja1000_priv *priv = netdev_priv(dev);
	469	struct net_device_stats *stats = &dev->stats;
	470	uint8_t isrc, status;
	471	int n = 0;
	472
	473	/* Shared interrupts and IRQ off? */
255a9154	474	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
429da1cc WG	475	return IRQ_NONE;
	476
	477	if (priv->pre_irq)
255a9154	478	priv->pre_irq(priv);
429da1cc	479
255a9154	480	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
429da1cc	481	n++;
255a9154	482	status = priv->read_reg(priv, REG_SR);
429da1cc WG	483
	484	if (isrc & IRQ_WUI)
	485	dev_warn(dev->dev.parent, "wakeup interrupt\n");
	486
	487	if (isrc & IRQ_TI) {
	488	/* transmission complete interrupt */
	489	stats->tx_packets++;
	490	can_get_echo_skb(dev, 0);
	491	netif_wake_queue(dev);
	492	}
	493	if (isrc & IRQ_RI) {
	494	/* receive interrupt */
	495	while (status & SR_RBS) {
	496	sja1000_rx(dev);
255a9154	497	status = priv->read_reg(priv, REG_SR);
429da1cc WG	498	}
	499	}
	500	if (isrc & (IRQ_DOI \| IRQ_EI \| IRQ_BEI \| IRQ_EPI \| IRQ_ALI)) {
	501	/* error interrupt */
	502	if (sja1000_err(dev, isrc, status))
	503	break;
	504	}
	505	}
	506
	507	if (priv->post_irq)
255a9154	508	priv->post_irq(priv);
429da1cc WG	509
	510	if (n >= SJA1000_MAX_IRQ)
	511	dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
	512
	513	return (n) ? IRQ_HANDLED : IRQ_NONE;
	514	}
	515	EXPORT_SYMBOL_GPL(sja1000_interrupt);
	516
	517	static int sja1000_open(struct net_device *dev)
	518	{
	519	struct sja1000_priv *priv = netdev_priv(dev);
	520	int err;
	521
	522	/* set chip into reset mode */
	523	set_reset_mode(dev);
	524
	525	/* common open */
	526	err = open_candev(dev);
	527	if (err)
	528	return err;
	529
	530	/* register interrupt handler, if not done by the device driver */
	531	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
	532	err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags,
	533	dev->name, (void *)dev);
	534	if (err) {
429da1cc	535	close_candev(dev);
128ced8f	536	return -EAGAIN;
429da1cc WG	537	}
	538	}
	539
	540	/* init and start chi */
	541	sja1000_start(dev);
	542	priv->open_time = jiffies;
	543
	544	netif_start_queue(dev);
	545
	546	return 0;
	547	}
	548
	549	static int sja1000_close(struct net_device *dev)
	550	{
	551	struct sja1000_priv *priv = netdev_priv(dev);
	552
	553	netif_stop_queue(dev);
	554	set_reset_mode(dev);
	555
	556	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
	557	free_irq(dev->irq, (void *)dev);
	558
	559	close_candev(dev);
	560
	561	priv->open_time = 0;
	562
	563	return 0;
	564	}
	565
	566	struct net_device *alloc_sja1000dev(int sizeof_priv)
	567	{
	568	struct net_device *dev;
	569	struct sja1000_priv *priv;
	570
	571	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv);
	572	if (!dev)
	573	return NULL;
	574
	575	priv = netdev_priv(dev);
	576
	577	priv->dev = dev;
	578	priv->can.bittiming_const = &sja1000_bittiming_const;
	579	priv->can.do_set_bittiming = sja1000_set_bittiming;
	580	priv->can.do_set_mode = sja1000_set_mode;
	581
	582	if (sizeof_priv)
	583	priv->priv = (void *)priv + sizeof(struct sja1000_priv);
	584
	585	return dev;
	586	}
	587	EXPORT_SYMBOL_GPL(alloc_sja1000dev);
	588
	589	void free_sja1000dev(struct net_device *dev)
	590	{
	591	free_candev(dev);
	592	}
	593	EXPORT_SYMBOL_GPL(free_sja1000dev);
	594
	595	static const struct net_device_ops sja1000_netdev_ops = {
	596	.ndo_open = sja1000_open,
	597	.ndo_stop = sja1000_close,
	598	.ndo_start_xmit = sja1000_start_xmit,
	599	};
	600
601	int register_sja1000dev(struct net_device *dev)
602	{
603	if (!sja1000_probe_chip(dev))
604	return -ENODEV;
605
606	dev->flags \|= IFF_ECHO; /* we support local echo */
607	dev->netdev_ops = &sja1000_netdev_ops;
608
609	set_reset_mode(dev);
610	chipset_init(dev);
611
612	return register_candev(dev);
613	}
614	EXPORT_SYMBOL_GPL(register_sja1000dev);
615
616	void unregister_sja1000dev(struct net_device *dev)
617	{
618	set_reset_mode(dev);
619	unregister_candev(dev);
620	}
621	EXPORT_SYMBOL_GPL(unregister_sja1000dev);
622
623	static __init int sja1000_init(void)
624	{
625	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
626
627	return 0;
628	}
629
630	module_init(sja1000_init);
631
632	static __exit void sja1000_exit(void)
633	{
634	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
635	}
636
637	module_exit(sja1000_exit);