RE: [PATCH v3] can: m_can: add support for one shot mode

["pankj.sharma" <pankj.sharma@samsung.com>]

Gentle Ping!

> From: Pankaj Sharma <pankj.sharma@samsung.com>
> Subject: [PATCH v3] 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: Pankaj Sharma <pankj.sharma@samsung.com>
> Signed-off-by: Sriram Dash <sriram.dash@samsung.com>
> ---
> 
> changes in v3:
> - resolving build errors for net-next branch
> 
> changes in v2:
> - rebase to net-next
> 
>  drivers/net/can/m_can/m_can.c | 12 +++++++++---
>  1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
> index 562c8317e3aa..75e7490c4299 100644
> --- a/drivers/net/can/m_can/m_can.c
> +++ b/drivers/net/can/m_can/m_can.c
> @@ -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) {
> --
> 2.17.1