- 根目录:
- 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.
*
*/
#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/dev.h>
#include <linux/can/error.h>
#include <linux/can/led.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 const 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 void sja1000_write_cmdreg(struct sja1000_priv *priv, u8 val)
{
unsigned long flags;
/*
* The command register needs some locking and time to settle
* the write_reg() operation - especially on SMP systems.
*/
spin_lock_irqsave(&priv->cmdreg_lock, flags);
priv->write_reg(priv, SJA1000_CMR, val);
priv->read_reg(priv, SJA1000_SR);
spin_unlock_irqrestore(&priv->cmdreg_lock, flags);
}
static int sja1000_is_absent(struct sja1000_priv *priv)
{
return (priv->read_reg(priv, SJA1000_MOD) == 0xFF);
}
static int sja1000_probe_chip(struct net_device *dev)
{
struct sja1000_priv *priv = netdev_priv(dev);
if (priv->reg_base && sja1000_is_absent(priv)) {
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, SJA1000_MOD);
int i;
/* disable interrupts */
priv->write_reg(priv, SJA1000_IER, IRQ_OFF);
for (i = 0; i < 100; i++) {
/* check reset bit */
if (status & MOD_RM) {
priv->can.state = CAN_STATE_STOPPED;
return;
}
/* reset chip */
priv->write_reg(priv, SJA1000_MOD, MOD_RM);
udelay(10);
status = priv->read_reg(priv, SJA1000_MOD);
}
netdev_err(dev, "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, SJA1000_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 interrupts */
if (priv->can.ctrlmode & CAN_CTRLMODE_BERR_REPORTING)
priv->write_reg(priv, SJA1000_IER, IRQ_ALL);
else
priv->write_reg(priv, SJA1000_IER,
IRQ_ALL & ~IRQ_BEI);
return;
}
/* set chip to normal mode */
if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
priv->write_reg(priv, SJA1000_MOD, MOD_LOM);
else
priv->write_reg(priv, SJA1000_MOD, 0x00);
udelay(10);
status = priv->read_reg(priv, SJA1000_MOD);
}
netdev_err(dev, "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, SJA1000_TXERR, 0x0);
priv->write_reg(priv, SJA1000_RXERR, 0x0);
priv->read_reg(priv, SJA1000_ECC);
/* leave reset mode */
set_normal_mode(dev);
}
static int sja1000_set_mode(struct net_device *dev, enum can_mode mode)
{
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;
netdev_info(dev, "setting BTR0=0x%02x BTR1=0x%02x\n", btr0, btr1);
priv->write_reg(priv, SJA1000_BTR0, btr0);
priv->write_reg(priv, SJA1000_BTR1, btr1);
return 0;
}
static int sja1000_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct sja1000_priv *priv = netdev_priv(dev);
bec->txerr = priv->read_reg(priv, SJA1000_TXERR);
bec->rxerr = priv->read_reg(priv, SJA1000_RXERR);
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, SJA1000_CDR, priv->cdr | CDR_PELICAN);
/* set acceptance filter (accept all) */
priv->write_reg(priv, SJA1000_ACCC0, 0x00);
priv->write_reg(priv, SJA1000_ACCC1, 0x00);
priv->write_reg(priv, SJA1000_ACCC2, 0x00);
priv->write_reg(priv, SJA1000_ACCC3, 0x00);
priv->write_reg(priv, SJA1000_ACCM0, 0xFF);
priv->write_reg(priv, SJA1000_ACCM1, 0xFF);
priv->write_reg(priv, SJA1000_ACCM2, 0xFF);
priv->write_reg(priv, SJA1000_ACCM3, 0xFF);
priv->write_reg(priv, SJA1000_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 can_frame *cf = (struct can_frame *)skb->data;
uint8_t fi;
uint8_t dlc;
canid_t id;
uint8_t dreg;
int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
fi = dlc = cf->can_dlc;
id = cf->can_id;
if (id & CAN_RTR_FLAG)
fi |= SJA1000_FI_RTR;
if (id & CAN_EFF_FLAG) {
fi |= SJA1000_FI_FF;
dreg = SJA1000_EFF_BUF;
priv->write_reg(priv, SJA1000_FI, fi);
priv->write_reg(priv, SJA1000_ID1, (id & 0x1fe00000) >> 21);
priv->write_reg(priv, SJA1000_ID2, (id & 0x001fe000) >> 13);
priv->write_reg(priv, SJA1000_ID3, (id & 0x00001fe0) >> 5);
priv->write_reg(priv, SJA1000_ID4, (id & 0x0000001f) << 3);
} else {
dreg = SJA1000_SFF_BUF;
priv->write_reg(priv, SJA1000_FI, fi);
priv->write_reg(priv, SJA1000_ID1, (id & 0x000007f8) >> 3);
priv->write_reg(priv, SJA1000_ID2, (id & 0x00000007) << 5);
}
for (i = 0; i < dlc; i++)
priv->write_reg(priv, dreg++, cf->data[i]);
can_put_echo_skb(skb, dev, 0);
if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
sja1000_write_cmdreg(priv, CMD_TR | CMD_AT);
else
sja1000_write_cmdreg(priv, 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;
int i;
/* create zero'ed CAN frame buffer */
skb = alloc_can_skb(dev, &cf);
if (skb == NULL)
return;
fi = priv->read_reg(priv, SJA1000_FI);
if (fi & SJA1000_FI_FF) {
/* extended frame format (EFF) */
dreg = SJA1000_EFF_BUF;
id = (priv->read_reg(priv, SJA1000_ID1) << 21)
| (priv->read_reg(priv, SJA1000_ID2) << 13)
| (priv->read_reg(priv, SJA1000_ID3) << 5)
| (priv->read_reg(priv, SJA1000_ID4) >> 3);
id |= CAN_EFF_FLAG;
} else {
/* standard frame format (SFF) */
dreg = SJA1000_SFF_BUF;
id = (priv->read_reg(priv, SJA1000_ID1) << 3)
| (priv->read_reg(priv, SJA1000_ID2) >> 5);
}
cf->can_dlc = get_can_dlc(fi & 0x0F);
if (fi & SJA1000_FI_RTR) {
id |= CAN_RTR_FLAG;
} else {
for (i = 0; i < cf->can_dlc; i++)
cf->data[i] = priv->read_reg(priv, dreg++);
}
cf->can_id = id;
/* release receive buffer */
sja1000_write_cmdreg(priv, CMD_RRB);
netif_rx(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
can_led_event(dev, CAN_LED_EVENT_RX);
}
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 = alloc_can_err_skb(dev, &cf);
if (skb == NULL)
return -ENOMEM;
if (isrc & IRQ_DOI) {
/* data overrun interrupt */
netdev_dbg(dev, "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++;
sja1000_write_cmdreg(priv, CMD_CDO); /* clear bit */
}
if (isrc & IRQ_EI) {
/* error warning interrupt */
netdev_dbg(dev, "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, SJA1000_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 occurred during transmission? */
if ((ecc & ECC_DIR) == 0)
cf->data[2] |= CAN_ERR_PROT_TX;
}
if (isrc & IRQ_EPI) {
/* error passive interrupt */
netdev_dbg(dev, "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 */
netdev_dbg(dev, "arbitration lost interrupt\n");
alc = priv->read_reg(priv, SJA1000_ALC);
priv->can.can_stats.arbitration_lost++;
stats->tx_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, SJA1000_RXERR);
uint8_t txerr = priv->read_reg(priv, SJA1000_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;
}
cf->data[6] = txerr;
cf->data[7] = rxerr;
}
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, SJA1000_IER) == IRQ_OFF)
return IRQ_NONE;
if (priv->pre_irq)
priv->pre_irq(priv);
while ((isrc = priv->read_reg(priv, SJA1000_IR)) &&
(n < SJA1000_MAX_IRQ)) {
n++;
status = priv->read_reg(priv, SJA1000_SR);
/* check for absent controller due to hw unplug */
if (status == 0xFF && sja1000_is_absent(priv))
return IRQ_NONE;
if (isrc & IRQ_WUI)
netdev_warn(dev, "wakeup interrupt\n");
if (isrc & IRQ_TI) {
/* transmission buffer released */
if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT &&
!(status & SR_TCS)) {
stats->tx_errors++;
can_free_echo_skb(dev, 0);
} else {
/* transmission complete */
stats->tx_bytes +=
priv->read_reg(priv, SJA1000_FI) & 0xf;
stats->tx_packets++;
can_get_echo_skb(dev, 0);
}
netif_wake_queue(dev);
can_led_event(dev, CAN_LED_EVENT_TX);
}
if (isrc & IRQ_RI) {
/* receive interrupt */
while (status & SR_RBS) {
sja1000_rx(dev);
status = priv->read_reg(priv, SJA1000_SR);
/* check for absent controller */
if (status == 0xFF && sja1000_is_absent(priv))
return IRQ_NONE;
}
}
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)
netdev_dbg(dev, "%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);
can_led_event(dev, CAN_LED_EVENT_OPEN);
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);
can_led_event(dev, CAN_LED_EVENT_STOP);
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,
SJA1000_ECHO_SKB_MAX);
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;
priv->can.do_get_berr_counter = sja1000_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES |
CAN_CTRLMODE_BERR_REPORTING | CAN_CTRLMODE_LISTENONLY |
CAN_CTRLMODE_ONE_SHOT;
spin_lock_init(&priv->cmdreg_lock);
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)
{
int ret;
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);
ret = register_candev(dev);
if (!ret)
devm_can_led_init(dev);
return ret;
}
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);