Commit fb7d6a81 authored by Pankaj Sharma's avatar Pankaj Sharma Committed by Marc Kleine-Budde
Browse files

can: m_can: add support for one shot mode 



According to the CAN Specification (see ISO 11898-1:2015, 8.3.4
Recovery Management), the M_CAN provides means for automatic
retransmission of frames that have lost arbitration or that
have been disturbed by errors during transmission. By default
automatic retransmission is enabled.

The Bosch MCAN controller has support for disabling automatic
retransmission.

To support time-triggered communication as described in ISO
11898-1:2015, chapter 9.2, the automatic retransmission may be
disabled via CCCR.DAR.

CAN_CTRLMODE_ONE_SHOT is used for disabling automatic retransmission.

Signed-off-by: default avatarPankaj Sharma <pankj.sharma@samsung.com>
Signed-off-by: default avatarSriram Dash <sriram.dash@samsung.com>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 0ff8ee89

drivers/net/can/m_can/m_can.c

+9 −3
Original line number Diff line number Diff line
@@ -123,6 +123,7 @@ enum m_can_reg { 
#define CCCR_CME_CANFD_BRS	0x2

#define CCCR_TXP		BIT(14)

#define CCCR_TEST		BIT(7)

#define CCCR_DAR		BIT(6)

#define CCCR_MON		BIT(5)

#define CCCR_CSR		BIT(4)

#define CCCR_CSA		BIT(3)
@@ -1135,7 +1136,7 @@ static void m_can_chip_config(struct net_device *dev) 
	if (cdev->version == 30) {

	/* Version 3.0.x */



		cccr &= ~(CCCR_TEST | CCCR_MON |

		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_DAR |

			(CCCR_CMR_MASK << CCCR_CMR_SHIFT) |

			(CCCR_CME_MASK << CCCR_CME_SHIFT));
@@ -1145,7 +1146,7 @@ static void m_can_chip_config(struct net_device *dev) 
	} else {

	/* Version 3.1.x or 3.2.x */

		cccr &= ~(CCCR_TEST | CCCR_MON | CCCR_BRSE | CCCR_FDOE |

			  CCCR_NISO);

			  CCCR_NISO | CCCR_DAR);



		/* Only 3.2.x has NISO Bit implemented */

		if (cdev->can.ctrlmode & CAN_CTRLMODE_FD_NON_ISO)
@@ -1165,6 +1166,10 @@ static void m_can_chip_config(struct net_device *dev) 
	if (cdev->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)

		cccr |= CCCR_MON;



	/* Disable Auto Retransmission (all versions) */

	if (cdev->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)

		cccr |= CCCR_DAR;



	/* Write config */

	m_can_write(cdev, M_CAN_CCCR, cccr);

	m_can_write(cdev, M_CAN_TEST, test);
@@ -1310,7 +1315,8 @@ static int m_can_dev_setup(struct m_can_classdev *m_can_dev) 
	m_can_dev->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |

					CAN_CTRLMODE_LISTENONLY |

					CAN_CTRLMODE_BERR_REPORTING |

					CAN_CTRLMODE_FD;

					CAN_CTRLMODE_FD |

					CAN_CTRLMODE_ONE_SHOT;



	/* Set properties depending on M_CAN version */

	switch (m_can_dev->version) {

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