can: sja1000: Validate initialization state in start method

When sja1000 is not compiled as module the SJA1000 chip is only
initialized during device registration on kernel boot. Should the chip
get a hardware reset there is no way to reinitialize it without re-
booting the Linux kernel.

This patch adds a check in sja1000_start if the chip is initialized, if
not we initialize it.

Signed-off-by: Mirza Krak <mirza.krak@hostmobility.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Mirza Krak 2014-08-08 14:30:50 +02:00 committed by Marc Kleine-Budde
parent 02784f1b05
commit 9e37bc6c63

View File

@ -172,6 +172,35 @@ static void set_normal_mode(struct net_device *dev)
netdev_err(dev, "setting SJA1000 into normal mode failed!\n");
}
/*
* 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);
}
static void sja1000_start(struct net_device *dev)
{
struct sja1000_priv *priv = netdev_priv(dev);
@ -180,6 +209,10 @@ static void sja1000_start(struct net_device *dev)
if (priv->can.state != CAN_STATE_STOPPED)
set_reset_mode(dev);
/* Initialize chip if uninitialized at this stage */
if (!(priv->read_reg(priv, SJA1000_CDR) & CDR_PELICAN))
chipset_init(dev);
/* Clear error counters and error code capture */
priv->write_reg(priv, SJA1000_TXERR, 0x0);
priv->write_reg(priv, SJA1000_RXERR, 0x0);
@ -236,35 +269,6 @@ static int sja1000_get_berr_counter(const struct net_device *dev,
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: