can: esd_402_pci: Add support for one-shot mode

This patch adds support for one-shot mode. In this mode there happens no
automatic retransmission in the case of an arbitration lost error or on
any bus error.
Signed-off-by: Stefan Mätje <stefan.maetje@esd.eu>
Link: https://lore.kernel.org/all/20240717214409.3934333-3-stefan.maetje@esd.euSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/esd/esd_402_pci-core.c

@@ -369,12 +369,13 @@ static int pci402_init_cores(struct pci_dev *pdev)
 		SET_NETDEV_DEV(netdev, &pdev->dev);
 
 		priv = netdev_priv(netdev);
+		priv->can.clock.freq = card->ov.core_frequency;
 		priv->can.ctrlmode_supported = CAN_CTRLMODE_LOOPBACK |
 			CAN_CTRLMODE_LISTENONLY |
 			CAN_CTRLMODE_BERR_REPORTING |
 			CAN_CTRLMODE_CC_LEN8_DLC;
-
-		priv->can.clock.freq = card->ov.core_frequency;
+		if (card->ov.features & ACC_OV_REG_FEAT_MASK_DAR)
+			priv->can.ctrlmode_supported |= CAN_CTRLMODE_ONE_SHOT;
 		if (card->ov.features & ACC_OV_REG_FEAT_MASK_CANFD)
 			priv->can.bittiming_const = &pci402_bittiming_const_canfd;
 		else

drivers/net/can/esd/esdacc.c

@@ -17,6 +17,9 @@
 /* esdACC DLC register layout */
 #define ACC_DLC_DLC_MASK GENMASK(3, 0)
 #define ACC_DLC_RTR_FLAG BIT(4)
+#define ACC_DLC_SSTX_FLAG BIT(24)	/* Single Shot TX */
+
+/* esdACC DLC in struct acc_bmmsg_rxtxdone::acc_dlc.len only! */
 #define ACC_DLC_TXD_FLAG BIT(5)
 
 /* ecc value of esdACC equals SJA1000's ECC register */
@@ -59,7 +62,7 @@ static void acc_resetmode_leave(struct acc_core *core)
 	acc_resetmode_entered(core);
 }
 
-static void acc_txq_put(struct acc_core *core, u32 acc_id, u8 acc_dlc,
+static void acc_txq_put(struct acc_core *core, u32 acc_id, u32 acc_dlc,
 			const void *data)
 {
 	acc_write32_noswap(core, ACC_CORE_OF_TXFIFO_DATA_1,
@@ -249,7 +252,7 @@ netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 	u8 tx_fifo_head = core->tx_fifo_head;
 	int fifo_usage;
 	u32 acc_id;
-	u8 acc_dlc;
+	u32 acc_dlc;
 
 	if (can_dropped_invalid_skb(netdev, skb))
 		return NETDEV_TX_OK;
@@ -274,6 +277,8 @@ netdev_tx_t acc_start_xmit(struct sk_buff *skb, struct net_device *netdev)
 	acc_dlc = can_get_cc_dlc(cf, priv->can.ctrlmode);
 	if (cf->can_id & CAN_RTR_FLAG)
 		acc_dlc |= ACC_DLC_RTR_FLAG;
+	if (priv->can.ctrlmode & CAN_CTRLMODE_ONE_SHOT)
+		acc_dlc |= ACC_DLC_SSTX_FLAG;
 
 	if (cf->can_id & CAN_EFF_FLAG) {
 		acc_id = cf->can_id & CAN_EFF_MASK;

drivers/net/can/esd/esdacc.h

@@ -35,6 +35,7 @@
  */
 #define ACC_OV_REG_FEAT_MASK_CANFD BIT(27 - 16)
 #define ACC_OV_REG_FEAT_MASK_NEW_PSC BIT(28 - 16)
+#define ACC_OV_REG_FEAT_MASK_DAR BIT(30 - 16)
 
 #define ACC_OV_REG_MODE_MASK_ENDIAN_LITTLE BIT(0)
 #define ACC_OV_REG_MODE_MASK_BM_ENABLE BIT(1)