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Commit 9fac1d1a authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Marc Kleine-Budde
Browse files

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: default avatarBenedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 130a5171

drivers/net/can/c_can/c_can.c

+23 −3
Original line number Diff line number Diff line
@@ -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);

}



/*