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authorMirza Krak <mirza.krak@hostmobility.com>2014-08-08 14:30:50 +0200
committerMarc Kleine-Budde <mkl@pengutronix.de>2014-08-21 10:49:34 +0200
commit9e37bc6c635a85e0ae3067f19d6f84e1c4516a6c (patch)
treeb2d78309495db7433d427c35f463727e18faf4ab /drivers
parent02784f1b05b8f241c8180af88869e717e2758593 (diff)
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/can/sja1000/sja1000.c62
1 files changed, 33 insertions, 29 deletions
diff --git a/drivers/net/can/sja1000/sja1000.c b/drivers/net/can/sja1000/sja1000.c
index d1692154ed1b..b27ac6074afb 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