linux/drivers/net/can/bfin_can.c

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/*
* Blackfin On-Chip CAN Driver
*
* Copyright 2004-2009 Analog Devices Inc.
*
* Enter bugs at http://blackfin.uclinux.org/
*
* Licensed under the GPL-2 or later.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/platform_device.h>
#include <linux/can/dev.h>
#include <linux/can/error.h>
#include <asm/bfin_can.h>
#include <asm/portmux.h>
#define DRV_NAME "bfin_can"
#define BFIN_CAN_TIMEOUT 100
#define TX_ECHO_SKB_MAX 1
/*
* bfin can private data
*/
struct bfin_can_priv {
struct can_priv can; /* must be the first member */
struct net_device *dev;
void __iomem *membase;
int rx_irq;
int tx_irq;
int err_irq;
unsigned short *pin_list;
};
/*
* bfin can timing parameters
*/
static struct can_bittiming_const bfin_can_bittiming_const = {
.name = DRV_NAME,
.tseg1_min = 1,
.tseg1_max = 16,
.tseg2_min = 1,
.tseg2_max = 8,
.sjw_max = 4,
/*
* Although the BRP field can be set to any value, it is recommended
* that the value be greater than or equal to 4, as restrictions
* apply to the bit timing configuration when BRP is less than 4.
*/
.brp_min = 4,
.brp_max = 1024,
.brp_inc = 1,
};
static int bfin_can_set_bittiming(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
struct can_bittiming *bt = &priv->can.bittiming;
u16 clk, timing;
clk = bt->brp - 1;
timing = ((bt->sjw - 1) << 8) | (bt->prop_seg + bt->phase_seg1 - 1) |
((bt->phase_seg2 - 1) << 4);
/*
* If the SAM bit is set, the input signal is oversampled three times
* at the SCLK rate.
*/
if (priv->can.ctrlmode & CAN_CTRLMODE_3_SAMPLES)
timing |= SAM;
bfin_write(&reg->clock, clk);
bfin_write(&reg->timing, timing);
netdev_info(dev, "setting CLOCK=0x%04x TIMING=0x%04x\n", clk, timing);
return 0;
}
static void bfin_can_set_reset_mode(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
int timeout = BFIN_CAN_TIMEOUT;
int i;
/* disable interrupts */
bfin_write(&reg->mbim1, 0);
bfin_write(&reg->mbim2, 0);
bfin_write(&reg->gim, 0);
/* reset can and enter configuration mode */
bfin_write(&reg->control, SRS | CCR);
SSYNC();
bfin_write(&reg->control, CCR);
SSYNC();
while (!(bfin_read(&reg->control) & CCA)) {
udelay(10);
if (--timeout == 0) {
netdev_err(dev, "fail to enter configuration mode\n");
BUG();
}
}
/*
* All mailbox configurations are marked as inactive
* by writing to CAN Mailbox Configuration Registers 1 and 2
* For all bits: 0 - Mailbox disabled, 1 - Mailbox enabled
*/
bfin_write(&reg->mc1, 0);
bfin_write(&reg->mc2, 0);
/* Set Mailbox Direction */
bfin_write(&reg->md1, 0xFFFF); /* mailbox 1-16 are RX */
bfin_write(&reg->md2, 0); /* mailbox 17-32 are TX */
/* RECEIVE_STD_CHL */
for (i = 0; i < 2; i++) {
bfin_write(&reg->chl[RECEIVE_STD_CHL + i].id0, 0);
bfin_write(&reg->chl[RECEIVE_STD_CHL + i].id1, AME);
bfin_write(&reg->chl[RECEIVE_STD_CHL + i].dlc, 0);
bfin_write(&reg->msk[RECEIVE_STD_CHL + i].amh, 0x1FFF);
bfin_write(&reg->msk[RECEIVE_STD_CHL + i].aml, 0xFFFF);
}
/* RECEIVE_EXT_CHL */
for (i = 0; i < 2; i++) {
bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].id0, 0);
bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].id1, AME | IDE);
bfin_write(&reg->chl[RECEIVE_EXT_CHL + i].dlc, 0);
bfin_write(&reg->msk[RECEIVE_EXT_CHL + i].amh, 0x1FFF);
bfin_write(&reg->msk[RECEIVE_EXT_CHL + i].aml, 0xFFFF);
}
bfin_write(&reg->mc2, BIT(TRANSMIT_CHL - 16));
bfin_write(&reg->mc1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
SSYNC();
priv->can.state = CAN_STATE_STOPPED;
}
static void bfin_can_set_normal_mode(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
int timeout = BFIN_CAN_TIMEOUT;
/*
* leave configuration mode
*/
bfin_write(&reg->control, bfin_read(&reg->control) & ~CCR);
while (bfin_read(&reg->status) & CCA) {
udelay(10);
if (--timeout == 0) {
netdev_err(dev, "fail to leave configuration mode\n");
BUG();
}
}
/*
* clear _All_ tx and rx interrupts
*/
bfin_write(&reg->mbtif1, 0xFFFF);
bfin_write(&reg->mbtif2, 0xFFFF);
bfin_write(&reg->mbrif1, 0xFFFF);
bfin_write(&reg->mbrif2, 0xFFFF);
/*
* clear global interrupt status register
*/
bfin_write(&reg->gis, 0x7FF); /* overwrites with '1' */
/*
* Initialize Interrupts
* - set bits in the mailbox interrupt mask register
* - global interrupt mask
*/
bfin_write(&reg->mbim1, BIT(RECEIVE_STD_CHL) + BIT(RECEIVE_EXT_CHL));
bfin_write(&reg->mbim2, BIT(TRANSMIT_CHL - 16));
bfin_write(&reg->gim, EPIM | BOIM | RMLIM);
SSYNC();
}
static void bfin_can_start(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
/* enter reset mode */
if (priv->can.state != CAN_STATE_STOPPED)
bfin_can_set_reset_mode(dev);
/* leave reset mode */
bfin_can_set_normal_mode(dev);
}
static int bfin_can_set_mode(struct net_device *dev, enum can_mode mode)
{
switch (mode) {
case CAN_MODE_START:
bfin_can_start(dev);
if (netif_queue_stopped(dev))
netif_wake_queue(dev);
break;
default:
return -EOPNOTSUPP;
}
return 0;
}
static int bfin_can_get_berr_counter(const struct net_device *dev,
struct can_berr_counter *bec)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
u16 cec = bfin_read(&reg->cec);
bec->txerr = cec >> 8;
bec->rxerr = cec;
return 0;
}
static int bfin_can_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
struct can_frame *cf = (struct can_frame *)skb->data;
u8 dlc = cf->can_dlc;
canid_t id = cf->can_id;
u8 *data = cf->data;
u16 val;
int i;
if (can_dropped_invalid_skb(dev, skb))
return NETDEV_TX_OK;
netif_stop_queue(dev);
/* fill id */
if (id & CAN_EFF_FLAG) {
bfin_write(&reg->chl[TRANSMIT_CHL].id0, id);
val = ((id & 0x1FFF0000) >> 16) | IDE;
} else
val = (id << 2);
if (id & CAN_RTR_FLAG)
val |= RTR;
bfin_write(&reg->chl[TRANSMIT_CHL].id1, val | AME);
/* fill payload */
for (i = 0; i < 8; i += 2) {
val = ((7 - i) < dlc ? (data[7 - i]) : 0) +
((6 - i) < dlc ? (data[6 - i] << 8) : 0);
bfin_write(&reg->chl[TRANSMIT_CHL].data[i], val);
}
/* fill data length code */
bfin_write(&reg->chl[TRANSMIT_CHL].dlc, dlc);
can_put_echo_skb(skb, dev, 0);
/* set transmit request */
bfin_write(&reg->trs2, BIT(TRANSMIT_CHL - 16));
return 0;
}
static void bfin_can_rx(struct net_device *dev, u16 isrc)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct net_device_stats *stats = &dev->stats;
struct bfin_can_regs __iomem *reg = priv->membase;
struct can_frame *cf;
struct sk_buff *skb;
int obj;
int i;
u16 val;
skb = alloc_can_skb(dev, &cf);
if (skb == NULL)
return;
/* get id */
if (isrc & BIT(RECEIVE_EXT_CHL)) {
/* extended frame format (EFF) */
cf->can_id = ((bfin_read(&reg->chl[RECEIVE_EXT_CHL].id1)
& 0x1FFF) << 16)
+ bfin_read(&reg->chl[RECEIVE_EXT_CHL].id0);
cf->can_id |= CAN_EFF_FLAG;
obj = RECEIVE_EXT_CHL;
} else {
/* standard frame format (SFF) */
cf->can_id = (bfin_read(&reg->chl[RECEIVE_STD_CHL].id1)
& 0x1ffc) >> 2;
obj = RECEIVE_STD_CHL;
}
if (bfin_read(&reg->chl[obj].id1) & RTR)
cf->can_id |= CAN_RTR_FLAG;
/* get data length code */
cf->can_dlc = get_can_dlc(bfin_read(&reg->chl[obj].dlc) & 0xF);
/* get payload */
for (i = 0; i < 8; i += 2) {
val = bfin_read(&reg->chl[obj].data[i]);
cf->data[7 - i] = (7 - i) < cf->can_dlc ? val : 0;
cf->data[6 - i] = (6 - i) < cf->can_dlc ? (val >> 8) : 0;
}
netif_rx(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
}
static int bfin_can_err(struct net_device *dev, u16 isrc, u16 status)
{
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
struct net_device_stats *stats = &dev->stats;
struct can_frame *cf;
struct sk_buff *skb;
enum can_state state = priv->can.state;
skb = alloc_can_err_skb(dev, &cf);
if (skb == NULL)
return -ENOMEM;
if (isrc & RMLIS) {
/* 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++;
}
if (isrc & BOIS) {
netdev_dbg(dev, "bus-off mode interrupt\n");
state = CAN_STATE_BUS_OFF;
cf->can_id |= CAN_ERR_BUSOFF;
can_bus_off(dev);
}
if (isrc & EPIS) {
/* error passive interrupt */
netdev_dbg(dev, "error passive interrupt\n");
state = CAN_STATE_ERROR_PASSIVE;
}
if ((isrc & EWTIS) || (isrc & EWRIS)) {
netdev_dbg(dev, "Error Warning Transmit/Receive Interrupt\n");
state = CAN_STATE_ERROR_WARNING;
}
if (state != priv->can.state && (state == CAN_STATE_ERROR_WARNING ||
state == CAN_STATE_ERROR_PASSIVE)) {
u16 cec = bfin_read(&reg->cec);
u8 rxerr = cec;
u8 txerr = cec >> 8;
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;
}
}
if (status) {
priv->can.can_stats.bus_error++;
cf->can_id |= CAN_ERR_PROT | CAN_ERR_BUSERROR;
if (status & BEF)
cf->data[2] |= CAN_ERR_PROT_BIT;
else if (status & FER)
cf->data[2] |= CAN_ERR_PROT_FORM;
else if (status & SER)
cf->data[2] |= CAN_ERR_PROT_STUFF;
else
cf->data[2] |= CAN_ERR_PROT_UNSPEC;
}
priv->can.state = state;
netif_rx(skb);
stats->rx_packets++;
stats->rx_bytes += cf->can_dlc;
return 0;
}
irqreturn_t bfin_can_interrupt(int irq, void *dev_id)
{
struct net_device *dev = dev_id;
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
struct net_device_stats *stats = &dev->stats;
u16 status, isrc;
if ((irq == priv->tx_irq) && bfin_read(&reg->mbtif2)) {
/* transmission complete interrupt */
bfin_write(&reg->mbtif2, 0xFFFF);
stats->tx_packets++;
stats->tx_bytes += bfin_read(&reg->chl[TRANSMIT_CHL].dlc);
can_get_echo_skb(dev, 0);
netif_wake_queue(dev);
} else if ((irq == priv->rx_irq) && bfin_read(&reg->mbrif1)) {
/* receive interrupt */
isrc = bfin_read(&reg->mbrif1);
bfin_write(&reg->mbrif1, 0xFFFF);
bfin_can_rx(dev, isrc);
} else if ((irq == priv->err_irq) && bfin_read(&reg->gis)) {
/* error interrupt */
isrc = bfin_read(&reg->gis);
status = bfin_read(&reg->esr);
bfin_write(&reg->gis, 0x7FF);
bfin_can_err(dev, isrc, status);
} else {
return IRQ_NONE;
}
return IRQ_HANDLED;
}
static int bfin_can_open(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
int err;
/* set chip into reset mode */
bfin_can_set_reset_mode(dev);
/* common open */
err = open_candev(dev);
if (err)
goto exit_open;
/* register interrupt handler */
err = request_irq(priv->rx_irq, &bfin_can_interrupt, 0,
"bfin-can-rx", dev);
if (err)
goto exit_rx_irq;
err = request_irq(priv->tx_irq, &bfin_can_interrupt, 0,
"bfin-can-tx", dev);
if (err)
goto exit_tx_irq;
err = request_irq(priv->err_irq, &bfin_can_interrupt, 0,
"bfin-can-err", dev);
if (err)
goto exit_err_irq;
bfin_can_start(dev);
netif_start_queue(dev);
return 0;
exit_err_irq:
free_irq(priv->tx_irq, dev);
exit_tx_irq:
free_irq(priv->rx_irq, dev);
exit_rx_irq:
close_candev(dev);
exit_open:
return err;
}
static int bfin_can_close(struct net_device *dev)
{
struct bfin_can_priv *priv = netdev_priv(dev);
netif_stop_queue(dev);
bfin_can_set_reset_mode(dev);
close_candev(dev);
free_irq(priv->rx_irq, dev);
free_irq(priv->tx_irq, dev);
free_irq(priv->err_irq, dev);
return 0;
}
struct net_device *alloc_bfin_candev(void)
{
struct net_device *dev;
struct bfin_can_priv *priv;
dev = alloc_candev(sizeof(*priv), TX_ECHO_SKB_MAX);
if (!dev)
return NULL;
priv = netdev_priv(dev);
priv->dev = dev;
priv->can.bittiming_const = &bfin_can_bittiming_const;
priv->can.do_set_bittiming = bfin_can_set_bittiming;
priv->can.do_set_mode = bfin_can_set_mode;
priv->can.do_get_berr_counter = bfin_can_get_berr_counter;
priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES;
return dev;
}
static const struct net_device_ops bfin_can_netdev_ops = {
.ndo_open = bfin_can_open,
.ndo_stop = bfin_can_close,
.ndo_start_xmit = bfin_can_start_xmit,
};
static int __devinit bfin_can_probe(struct platform_device *pdev)
{
int err;
struct net_device *dev;
struct bfin_can_priv *priv;
struct resource *res_mem, *rx_irq, *tx_irq, *err_irq;
unsigned short *pdata;
pdata = pdev->dev.platform_data;
if (!pdata) {
dev_err(&pdev->dev, "No platform data provided!\n");
err = -EINVAL;
goto exit;
}
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
rx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
tx_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 1);
err_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 2);
if (!res_mem || !rx_irq || !tx_irq || !err_irq) {
err = -EINVAL;
goto exit;
}
if (!request_mem_region(res_mem->start, resource_size(res_mem),
dev_name(&pdev->dev))) {
err = -EBUSY;
goto exit;
}
/* request peripheral pins */
err = peripheral_request_list(pdata, dev_name(&pdev->dev));
if (err)
goto exit_mem_release;
dev = alloc_bfin_candev();
if (!dev) {
err = -ENOMEM;
goto exit_peri_pin_free;
}
priv = netdev_priv(dev);
priv->membase = (void __iomem *)res_mem->start;
priv->rx_irq = rx_irq->start;
priv->tx_irq = tx_irq->start;
priv->err_irq = err_irq->start;
priv->pin_list = pdata;
priv->can.clock.freq = get_sclk();
dev_set_drvdata(&pdev->dev, dev);
SET_NETDEV_DEV(dev, &pdev->dev);
dev->flags |= IFF_ECHO; /* we support local echo */
dev->netdev_ops = &bfin_can_netdev_ops;
bfin_can_set_reset_mode(dev);
err = register_candev(dev);
if (err) {
dev_err(&pdev->dev, "registering failed (err=%d)\n", err);
goto exit_candev_free;
}
dev_info(&pdev->dev,
"%s device registered"
"(&reg_base=%p, rx_irq=%d, tx_irq=%d, err_irq=%d, sclk=%d)\n",
DRV_NAME, (void *)priv->membase, priv->rx_irq,
priv->tx_irq, priv->err_irq, priv->can.clock.freq);
return 0;
exit_candev_free:
free_candev(dev);
exit_peri_pin_free:
peripheral_free_list(pdata);
exit_mem_release:
release_mem_region(res_mem->start, resource_size(res_mem));
exit:
return err;
}
static int __devexit bfin_can_remove(struct platform_device *pdev)
{
struct net_device *dev = dev_get_drvdata(&pdev->dev);
struct bfin_can_priv *priv = netdev_priv(dev);
struct resource *res;
bfin_can_set_reset_mode(dev);
unregister_candev(dev);
dev_set_drvdata(&pdev->dev, NULL);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, resource_size(res));
peripheral_free_list(priv->pin_list);
free_candev(dev);
return 0;
}
#ifdef CONFIG_PM
static int bfin_can_suspend(struct platform_device *pdev, pm_message_t mesg)
{
struct net_device *dev = dev_get_drvdata(&pdev->dev);
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
int timeout = BFIN_CAN_TIMEOUT;
if (netif_running(dev)) {
/* enter sleep mode */
bfin_write(&reg->control, bfin_read(&reg->control) | SMR);
SSYNC();
while (!(bfin_read(&reg->intr) & SMACK)) {
udelay(10);
if (--timeout == 0) {
netdev_err(dev, "fail to enter sleep mode\n");
BUG();
}
}
}
return 0;
}
static int bfin_can_resume(struct platform_device *pdev)
{
struct net_device *dev = dev_get_drvdata(&pdev->dev);
struct bfin_can_priv *priv = netdev_priv(dev);
struct bfin_can_regs __iomem *reg = priv->membase;
if (netif_running(dev)) {
/* leave sleep mode */
bfin_write(&reg->intr, 0);
SSYNC();
}
return 0;
}
#else
#define bfin_can_suspend NULL
#define bfin_can_resume NULL
#endif /* CONFIG_PM */
static struct platform_driver bfin_can_driver = {
.probe = bfin_can_probe,
.remove = __devexit_p(bfin_can_remove),
.suspend = bfin_can_suspend,
.resume = bfin_can_resume,
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
};
module_platform_driver(bfin_can_driver);
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Blackfin on-chip CAN netdevice driver");