[PATCH 1/4] can: sja1000: Validate initialization state in start method
From: Marc Kleine-Budde <mkl@pengutronix.de>
Date: 2014-08-21 09:23:31
Also in:
linux-can
Subsystem:
can network drivers, the rest · Maintainers:
Marc Kleine-Budde, Vincent Mailhol, Linus Torvalds
From: Mirza Krak <redacted> 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 <redacted> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> --- drivers/net/can/sja1000/sja1000.c | 62 +++++++++++++++++++++------------------ 1 file changed, 33 insertions(+), 29 deletions(-)
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index d169215..b27ac60 100644
--- a/drivers/net/can/sja1000/sja1000.c
+++ b/drivers/net/can/sja1000/sja1000.c@@ -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);
@@ -237,35 +270,6 @@ static int sja1000_get_berr_counter(const struct net_device *dev, } /* - * 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
--
2.1.0.rc1