diff options
| author |   Thomas Gleixner <tglx@linutronix.de> | 2014-03-18 17:19:08 +0000 |
|---|---|---|
| committer |   Marc Kleine-Budde <mkl@pengutronix.de> | 2014-04-01 11:54:57 +0200 |
| commit | 9fac1d1ab8e66816c40a235a238357b1f1fc4dee (patch) | |
| tree | d277fa95c6ae7a6c3566d06d7b242c20dd9abebf /drivers/net/can/c_can | |
| parent | can: c_can: check return value to users of c_can_set_bittiming() (diff) | |
| download | linux-dev-9fac1d1ab8e66816c40a235a238357b1f1fc4dee.tar.xz linux-dev-9fac1d1ab8e66816c40a235a238357b1f1fc4dee.zip | |
can: c_can: Wait for CONTROL_INIT to be cleared
According to the documentation the CPU must wait for CONTROL_INIT to
be cleared before writing to the baudrate registers.
Signed-off-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can/c_can')
| -rw-r--r-- | drivers/net/can/c_can/c_can.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/drivers/net/can/c_can/c_can.c b/drivers/net/can/c_can/c_can.c index 68839380086d..4d08a32f27ac 100644 --- a/drivers/net/can/c_can/c_can.c +++ b/drivers/net/can/c_can/c_can.c @@ -566,6 +566,21 @@ static netdev_tx_t c_can_start_xmit(struct sk_buff *skb, return NETDEV_TX_OK; } +static int c_can_wait_for_ctrl_init(struct net_device *dev, + struct c_can_priv *priv, u32 init) +{ + int retry = 0; + + while (init != (priv->read_reg(priv, C_CAN_CTRL_REG) & CONTROL_INIT)) { + udelay(10); + if (retry++ > 1000) { + netdev_err(dev, "CCTRL: set CONTROL_INIT failed\n"); + return -EIO; + } + } + return 0; +} + static int c_can_set_bittiming(struct net_device *dev) { unsigned int reg_btr, reg_brpe, ctrl_save; @@ -573,6 +588,7 @@ static int c_can_set_bittiming(struct net_device *dev) u32 ten_bit_brp; struct c_can_priv *priv = netdev_priv(dev); const struct can_bittiming *bt = &priv->can.bittiming; + int res; /* c_can provides a 6-bit brp and 4-bit brpe fields */ ten_bit_brp = bt->brp - 1; @@ -590,13 +606,17 @@ static int c_can_set_bittiming(struct net_device *dev) "setting BTR=%04x BRPE=%04x\n", reg_btr, reg_brpe); ctrl_save = priv->read_reg(priv, C_CAN_CTRL_REG); - priv->write_reg(priv, C_CAN_CTRL_REG, - ctrl_save | CONTROL_CCE | CONTROL_INIT); + ctrl_save &= ~CONTROL_INIT; + priv->write_reg(priv, C_CAN_CTRL_REG, CONTROL_CCE | CONTROL_INIT); + res = c_can_wait_for_ctrl_init(dev, priv, CONTROL_INIT); + if (res) + return res; + priv->write_reg(priv, C_CAN_BTR_REG, reg_btr); priv->write_reg(priv, C_CAN_BRPEXT_REG, reg_brpe); priv->write_reg(priv, C_CAN_CTRL_REG, ctrl_save); - return 0; + return c_can_wait_for_ctrl_init(dev, priv, 0); } /* |