[linux.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 <[email protected]>
 *
 */

#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 "sja1000.h"

#define DRV_NAME "sja1000"

MODULE_AUTHOR("Oliver Hartkopp <[email protected]>");
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 netdev_tx_t 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);

	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);

	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 <[email protected]>
	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>
429da1cc WG	66
	67	#include "sja1000.h"
	68
	69	#define DRV_NAME "sja1000"
	70
	71	MODULE_AUTHOR("Oliver Hartkopp <[email protected]>");
	72	MODULE_LICENSE("Dual BSD/GPL");
	73	MODULE_DESCRIPTION(DRV_NAME "CAN netdevice driver");
	74
	75	static struct can_bittiming_const sja1000_bittiming_const = {
	76	.name = DRV_NAME,
	77	.tseg1_min = 1,
	78	.tseg1_max = 16,
	79	.tseg2_min = 1,
	80	.tseg2_max = 8,
	81	.sjw_max = 4,
	82	.brp_min = 1,
	83	.brp_max = 64,
	84	.brp_inc = 1,
	85	};
	86
	87	static int sja1000_probe_chip(struct net_device *dev)
	88	{
	89	struct sja1000_priv *priv = netdev_priv(dev);
	90
255a9154	91	if (priv->reg_base && (priv->read_reg(priv, 0) == 0xFF)) {
429da1cc WG	92	printk(KERN_INFO "%s: probing @0x%lX failed\n",
	93	DRV_NAME, dev->base_addr);
	94	return 0;
	95	}
	96	return -1;
	97	}
	98
	99	static void set_reset_mode(struct net_device *dev)
	100	{
	101	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	102	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	103	int i;
	104
	105	/* disable interrupts */
255a9154	106	priv->write_reg(priv, REG_IER, IRQ_OFF);
429da1cc WG	107
	108	for (i = 0; i < 100; i++) {
	109	/* check reset bit */
	110	if (status & MOD_RM) {
	111	priv->can.state = CAN_STATE_STOPPED;
	112	return;
	113	}
	114
255a9154	115	priv->write_reg(priv, REG_MOD, MOD_RM); /* reset chip */
429da1cc	116	udelay(10);
255a9154	117	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	118	}
	119
	120	dev_err(dev->dev.parent, "setting SJA1000 into reset mode failed!\n");
	121	}
	122
	123	static void set_normal_mode(struct net_device *dev)
	124	{
	125	struct sja1000_priv *priv = netdev_priv(dev);
255a9154	126	unsigned char status = priv->read_reg(priv, REG_MOD);
429da1cc WG	127	int i;
	128
	129	for (i = 0; i < 100; i++) {
	130	/* check reset bit */
	131	if ((status & MOD_RM) == 0) {
	132	priv->can.state = CAN_STATE_ERROR_ACTIVE;
	133	/* enable all interrupts */
255a9154	134	priv->write_reg(priv, REG_IER, IRQ_ALL);
429da1cc WG	135	return;
	136	}
	137
	138	/* set chip to normal mode */
255a9154	139	priv->write_reg(priv, REG_MOD, 0x00);
429da1cc	140	udelay(10);
255a9154	141	status = priv->read_reg(priv, REG_MOD);
429da1cc WG	142	}
	143
	144	dev_err(dev->dev.parent, "setting SJA1000 into normal mode failed!\n");
	145	}
	146
	147	static void sja1000_start(struct net_device *dev)
	148	{
	149	struct sja1000_priv *priv = netdev_priv(dev);
	150
	151	/* leave reset mode */
	152	if (priv->can.state != CAN_STATE_STOPPED)
	153	set_reset_mode(dev);
	154
	155	/* Clear error counters and error code capture */
255a9154 WG	156	priv->write_reg(priv, REG_TXERR, 0x0);
	157	priv->write_reg(priv, REG_RXERR, 0x0);
	158	priv->read_reg(priv, REG_ECC);
429da1cc WG	159
	160	/* leave reset mode */
	161	set_normal_mode(dev);
	162	}
	163
	164	static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
	165	{
	166	struct sja1000_priv *priv = netdev_priv(dev);
	167
	168	if (!priv->open_time)
	169	return -EINVAL;
	170
	171	switch (mode) {
	172	case CAN_MODE_START:
	173	sja1000_start(dev);
	174	if (netif_queue_stopped(dev))
	175	netif_wake_queue(dev);
	176	break;
	177
	178	default:
	179	return -EOPNOTSUPP;
	180	}
	181
	182	return 0;
	183	}
	184
	185	static int sja1000_set_bittiming(struct net_device *dev)
	186	{
	187	struct sja1000_priv *priv = netdev_priv(dev);
	188	struct can_bittiming *bt = &priv->can.bittiming;
	189	u8 btr0, btr1;
	190
	191	btr0 = ((bt->brp - 1) & 0x3f) \| (((bt->sjw - 1) & 0x3) << 6);
	192	btr1 = ((bt->prop_seg + bt->phase_seg1 - 1) & 0xf) \|
	193	(((bt->phase_seg2 - 1) & 0x7) << 4);
	194	if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
	195	btr1 \|= 0x80;
	196
	197	dev_info(dev->dev.parent,
	198	"setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
	199
255a9154 WG	200	priv->write_reg(priv, REG_BTR0, btr0);
255a9154 WG	201	priv->write_reg(priv, REG_BTR1, btr1);
429da1cc WG	202
	203	return 0;
	204	}
	205
	206	/*
	207	* initialize SJA1000 chip:
	208	* - reset chip
	209	* - set output mode
	210	* - set baudrate
	211	* - enable interrupts
	212	* - start operating mode
	213	*/
	214	static void chipset_init(struct net_device *dev)
	215	{
	216	struct sja1000_priv *priv = netdev_priv(dev);
	217
	218	/* set clock divider and output control register */
255a9154	219	priv->write_reg(priv, REG_CDR, priv->cdr \| CDR_PELICAN);
429da1cc WG	220
429da1cc WG	221	/* set acceptance filter (accept all) */
255a9154 WG	222	priv->write_reg(priv, REG_ACCC0, 0x00);
	223	priv->write_reg(priv, REG_ACCC1, 0x00);
	224	priv->write_reg(priv, REG_ACCC2, 0x00);
	225	priv->write_reg(priv, REG_ACCC3, 0x00);
429da1cc	226
255a9154 WG	227	priv->write_reg(priv, REG_ACCM0, 0xFF);
	228	priv->write_reg(priv, REG_ACCM1, 0xFF);
	229	priv->write_reg(priv, REG_ACCM2, 0xFF);
	230	priv->write_reg(priv, REG_ACCM3, 0xFF);
429da1cc	231
255a9154	232	priv->write_reg(priv, REG_OCR, priv->ocr \| OCR_MODE_NORMAL);
429da1cc WG	233	}
	234
	235	/*
	236	* transmit a CAN message
	237	* message layout in the sk_buff should be like this:
	238	* xx xx xx xx ff ll 00 11 22 33 44 55 66 77
	239	* [ can-id ] [flags] [len] [can data (up to 8 bytes]
	240	*/
61357325 SH	241	static netdev_tx_t sja1000_start_xmit(struct sk_buff *skb,
61357325 SH	242	struct net_device *dev)
429da1cc WG	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
429da1cc WG	343	stats->rx_packets++;
	344	stats->rx_bytes += dlc;
	345	}
	346
	347	static int sja1000_err(struct net_device *dev, uint8_t isrc, uint8_t status)
	348	{
	349	struct sja1000_priv *priv = netdev_priv(dev);
	350	struct net_device_stats *stats = &dev->stats;
	351	struct can_frame *cf;
	352	struct sk_buff *skb;
	353	enum can_state state = priv->can.state;
	354	uint8_t ecc, alc;
	355
	356	skb = dev_alloc_skb(sizeof(struct can_frame));
	357	if (skb == NULL)
	358	return -ENOMEM;
	359	skb->dev = dev;
	360	skb->protocol = htons(ETH_P_CAN);
	361	cf = (struct can_frame *)skb_put(skb, sizeof(struct can_frame));
	362	memset(cf, 0, sizeof(struct can_frame));
	363	cf->can_id = CAN_ERR_FLAG;
	364	cf->can_dlc = CAN_ERR_DLC;
	365
	366	if (isrc & IRQ_DOI) {
	367	/* data overrun interrupt */
	368	dev_dbg(dev->dev.parent, "data overrun interrupt\n");
	369	cf->can_id \|= CAN_ERR_CRTL;
	370	cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
	371	stats->rx_over_errors++;
	372	stats->rx_errors++;
255a9154	373	priv->write_reg(priv, REG_CMR, CMD_CDO); /* clear bit */
429da1cc WG	374	}
	375
	376	if (isrc & IRQ_EI) {
	377	/* error warning interrupt */
	378	dev_dbg(dev->dev.parent, "error warning interrupt\n");
	379
	380	if (status & SR_BS) {
	381	state = CAN_STATE_BUS_OFF;
	382	cf->can_id \|= CAN_ERR_BUSOFF;
	383	can_bus_off(dev);
	384	} else if (status & SR_ES) {
	385	state = CAN_STATE_ERROR_WARNING;
	386	} else
	387	state = CAN_STATE_ERROR_ACTIVE;
	388	}
	389	if (isrc & IRQ_BEI) {
	390	/* bus error interrupt */
	391	priv->can.can_stats.bus_error++;
	392	stats->rx_errors++;
	393
255a9154	394	ecc = priv->read_reg(priv, REG_ECC);
429da1cc WG	395
	396	cf->can_id \|= CAN_ERR_PROT \| CAN_ERR_BUSERROR;
	397
	398	switch (ecc & ECC_MASK) {
	399	case ECC_BIT:
	400	cf->data[2] \|= CAN_ERR_PROT_BIT;
	401	break;
	402	case ECC_FORM:
	403	cf->data[2] \|= CAN_ERR_PROT_FORM;
	404	break;
	405	case ECC_STUFF:
	406	cf->data[2] \|= CAN_ERR_PROT_STUFF;
	407	break;
	408	default:
	409	cf->data[2] \|= CAN_ERR_PROT_UNSPEC;
	410	cf->data[3] = ecc & ECC_SEG;
	411	break;
	412	}
	413	/* Error occured during transmission? */
	414	if ((ecc & ECC_DIR) == 0)
	415	cf->data[2] \|= CAN_ERR_PROT_TX;
	416	}
	417	if (isrc & IRQ_EPI) {
	418	/* error passive interrupt */
	419	dev_dbg(dev->dev.parent, "error passive interrupt\n");
	420	if (status & SR_ES)
	421	state = CAN_STATE_ERROR_PASSIVE;
	422	else
	423	state = CAN_STATE_ERROR_ACTIVE;
	424	}
	425	if (isrc & IRQ_ALI) {
	426	/* arbitration lost interrupt */
	427	dev_dbg(dev->dev.parent, "arbitration lost interrupt\n");
255a9154	428	alc = priv->read_reg(priv, REG_ALC);
429da1cc WG	429	priv->can.can_stats.arbitration_lost++;
	430	stats->rx_errors++;
	431	cf->can_id \|= CAN_ERR_LOSTARB;
	432	cf->data[0] = alc & 0x1f;
	433	}
	434
	435	if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING \|\|
	436	state == CAN_STATE_ERROR_PASSIVE)) {
255a9154 WG	437	uint8_t rxerr = priv->read_reg(priv, REG_RXERR);
255a9154 WG	438	uint8_t txerr = priv->read_reg(priv, REG_TXERR);
429da1cc WG	439	cf->can_id \|= CAN_ERR_CRTL;
	440	if (state == CAN_STATE_ERROR_WARNING) {
	441	priv->can.can_stats.error_warning++;
	442	cf->data[1] = (txerr > rxerr) ?
	443	CAN_ERR_CRTL_TX_WARNING :
	444	CAN_ERR_CRTL_RX_WARNING;
	445	} else {
	446	priv->can.can_stats.error_passive++;
	447	cf->data[1] = (txerr > rxerr) ?
	448	CAN_ERR_CRTL_TX_PASSIVE :
	449	CAN_ERR_CRTL_RX_PASSIVE;
	450	}
	451	}
	452
	453	priv->can.state = state;
	454
	455	netif_rx(skb);
	456
429da1cc WG	457	stats->rx_packets++;
	458	stats->rx_bytes += cf->can_dlc;
	459
	460	return 0;
	461	}
	462
	463	irqreturn_t sja1000_interrupt(int irq, void *dev_id)
	464	{
	465	struct net_device dev = (struct net_device )dev_id;
	466	struct sja1000_priv *priv = netdev_priv(dev);
	467	struct net_device_stats *stats = &dev->stats;
	468	uint8_t isrc, status;
	469	int n = 0;
	470
	471	/* Shared interrupts and IRQ off? */
255a9154	472	if (priv->read_reg(priv, REG_IER) == IRQ_OFF)
429da1cc WG	473	return IRQ_NONE;
	474
	475	if (priv->pre_irq)
255a9154	476	priv->pre_irq(priv);
429da1cc	477
255a9154	478	while ((isrc = priv->read_reg(priv, REG_IR)) && (n < SJA1000_MAX_IRQ)) {
429da1cc	479	n++;
255a9154	480	status = priv->read_reg(priv, REG_SR);
429da1cc WG	481
	482	if (isrc & IRQ_WUI)
	483	dev_warn(dev->dev.parent, "wakeup interrupt\n");
	484
	485	if (isrc & IRQ_TI) {
	486	/* transmission complete interrupt */
	487	stats->tx_packets++;
	488	can_get_echo_skb(dev, 0);
	489	netif_wake_queue(dev);
	490	}
	491	if (isrc & IRQ_RI) {
	492	/* receive interrupt */
	493	while (status & SR_RBS) {
	494	sja1000_rx(dev);
255a9154	495	status = priv->read_reg(priv, REG_SR);
429da1cc WG	496	}
	497	}
	498	if (isrc & (IRQ_DOI \| IRQ_EI \| IRQ_BEI \| IRQ_EPI \| IRQ_ALI)) {
	499	/* error interrupt */
	500	if (sja1000_err(dev, isrc, status))
	501	break;
	502	}
	503	}
	504
	505	if (priv->post_irq)
255a9154	506	priv->post_irq(priv);
429da1cc WG	507
	508	if (n >= SJA1000_MAX_IRQ)
	509	dev_dbg(dev->dev.parent, "%d messages handled in ISR", n);
	510
	511	return (n) ? IRQ_HANDLED : IRQ_NONE;
	512	}
	513	EXPORT_SYMBOL_GPL(sja1000_interrupt);
	514
	515	static int sja1000_open(struct net_device *dev)
	516	{
	517	struct sja1000_priv *priv = netdev_priv(dev);
	518	int err;
	519
	520	/* set chip into reset mode */
	521	set_reset_mode(dev);
	522
	523	/* common open */
	524	err = open_candev(dev);
	525	if (err)
	526	return err;
	527
	528	/* register interrupt handler, if not done by the device driver */
	529	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER)) {
	530	err = request_irq(dev->irq, &sja1000_interrupt, priv->irq_flags,
	531	dev->name, (void *)dev);
	532	if (err) {
429da1cc	533	close_candev(dev);
128ced8f	534	return -EAGAIN;
429da1cc WG	535	}
	536	}
	537
	538	/* init and start chi */
	539	sja1000_start(dev);
	540	priv->open_time = jiffies;
	541
	542	netif_start_queue(dev);
	543
	544	return 0;
	545	}
	546
	547	static int sja1000_close(struct net_device *dev)
	548	{
	549	struct sja1000_priv *priv = netdev_priv(dev);
	550
	551	netif_stop_queue(dev);
	552	set_reset_mode(dev);
	553
	554	if (!(priv->flags & SJA1000_CUSTOM_IRQ_HANDLER))
	555	free_irq(dev->irq, (void *)dev);
	556
	557	close_candev(dev);
	558
	559	priv->open_time = 0;
	560
	561	return 0;
	562	}
	563
	564	struct net_device *alloc_sja1000dev(int sizeof_priv)
	565	{
	566	struct net_device *dev;
	567	struct sja1000_priv *priv;
	568
	569	dev = alloc_candev(sizeof(struct sja1000_priv) + sizeof_priv);
	570	if (!dev)
	571	return NULL;
	572
	573	priv = netdev_priv(dev);
	574
	575	priv->dev = dev;
	576	priv->can.bittiming_const = &sja1000_bittiming_const;
	577	priv->can.do_set_bittiming = sja1000_set_bittiming;
	578	priv->can.do_set_mode = sja1000_set_mode;
	579
	580	if (sizeof_priv)
	581	priv->priv = (void *)priv + sizeof(struct sja1000_priv);
	582
	583	return dev;
	584	}
	585	EXPORT_SYMBOL_GPL(alloc_sja1000dev);
	586
	587	void free_sja1000dev(struct net_device *dev)
	588	{
	589	free_candev(dev);
	590	}
	591	EXPORT_SYMBOL_GPL(free_sja1000dev);
	592
	593	static const struct net_device_ops sja1000_netdev_ops = {
	594	.ndo_open = sja1000_open,
	595	.ndo_stop = sja1000_close,
	596	.ndo_start_xmit = sja1000_start_xmit,
	597	};
	598
599	int register_sja1000dev(struct net_device *dev)
600	{
601	if (!sja1000_probe_chip(dev))
602	return -ENODEV;
603
604	dev->flags \|= IFF_ECHO; /* we support local echo */
605	dev->netdev_ops = &sja1000_netdev_ops;
606
607	set_reset_mode(dev);
608	chipset_init(dev);
609
610	return register_candev(dev);
611	}
612	EXPORT_SYMBOL_GPL(register_sja1000dev);
613
614	void unregister_sja1000dev(struct net_device *dev)
615	{
616	set_reset_mode(dev);
617	unregister_candev(dev);
618	}
619	EXPORT_SYMBOL_GPL(unregister_sja1000dev);
620
621	static __init int sja1000_init(void)
622	{
623	printk(KERN_INFO "%s CAN netdevice driver\n", DRV_NAME);
624
625	return 0;
626	}
627
628	module_init(sja1000_init);
629
630	static __exit void sja1000_exit(void)
631	{
632	printk(KERN_INFO "%s: driver removed\n", DRV_NAME);
633	}
634
635	module_exit(sja1000_exit);