Commit 7ad0f53a authored by Pankaj Bansal's avatar Pankaj Bansal Committed by Marc Kleine-Budde
Browse files

can: flexcan: flexcan_chip_start(): enable loopback mode in flexcan 



Self reception disable bit needs to be cleared for loopback mode to work
in flexcan.

Signed-off-by: default avatarPankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent de3578c1

drivers/net/can/flexcan.c

+19 −3
Original line number Diff line number Diff line
@@ -995,7 +995,6 @@ static int flexcan_chip_start(struct net_device *dev) 
	 * halt now

	 * only supervisor access

	 * enable warning int

	 * disable local echo

	 * enable individual RX masking

	 * choose format C

	 * set max mailbox number
@@ -1003,8 +1002,8 @@ static int flexcan_chip_start(struct net_device *dev) 
	reg_mcr = priv->read(&regs->mcr);

	reg_mcr &= ~FLEXCAN_MCR_MAXMB(0xff);

	reg_mcr |= FLEXCAN_MCR_FRZ | FLEXCAN_MCR_HALT | FLEXCAN_MCR_SUPV |

		FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_SRX_DIS | FLEXCAN_MCR_IRMQ |

		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(FLEXCAN_TX_MB);

		FLEXCAN_MCR_WRN_EN | FLEXCAN_MCR_IRMQ | FLEXCAN_MCR_IDAM_C |

		FLEXCAN_MCR_MAXMB(FLEXCAN_TX_MB);



	/* MCR

	 *
@@ -1017,6 +1016,23 @@ static int flexcan_chip_start(struct net_device *dev) 
	else

		reg_mcr |= FLEXCAN_MCR_FEN;



	/* MCR

	 *

	 * NOTE: In loopback mode, the CAN_MCR[SRXDIS] cannot be

	 *       asserted because this will impede the self reception

	 *       of a transmitted message. This is not documented in

	 *       earlier versions of flexcan block guide.

	 *

	 * Self Reception:

	 * - enable Self Reception for loopback mode

	 *   (by clearing "Self Reception Disable" bit)

	 * - disable for normal operation

	 */

	if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)

		reg_mcr &= ~FLEXCAN_MCR_SRX_DIS;

	else

		reg_mcr |= FLEXCAN_MCR_SRX_DIS;



	netdev_dbg(dev, "%s: writing mcr=0x%08x", __func__, reg_mcr);

	priv->write(reg_mcr, &regs->mcr);