can: flexcan: remove not needed struct flexcan_priv::tx_mb and struct flexcan_priv::tx_mb_idx

The previous patch changes the TX path to always use the last mailbox
regardless of the used offload scheme (rx-fifo or timestamp based). This
means members "tx_mb" and "tx_mb_idx" of the struct flexcan_priv don't
depend on the offload scheme, so replace them by compile time constants.

Cc: linux-stable <stable@vger.kernel.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/flexcan.c

@@ -258,9 +258,7 @@ struct flexcan_priv {
 	struct can_rx_offload offload;
 
 	struct flexcan_regs __iomem *regs;
-	struct flexcan_mb __iomem *tx_mb;
 	struct flexcan_mb __iomem *tx_mb_reserved;
-	u8 tx_mb_idx;
 	u32 reg_ctrl_default;
 	u32 reg_imask1_default;
 	u32 reg_imask2_default;
@@ -514,6 +512,7 @@ static int flexcan_get_berr_counter(const struct net_device *dev,
 static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	const struct flexcan_priv *priv = netdev_priv(dev);
+	struct flexcan_regs __iomem *regs = priv->regs;
 	struct can_frame *cf = (struct can_frame *)skb->data;
 	u32 can_id;
 	u32 data;
@@ -536,17 +535,17 @@ static netdev_tx_t flexcan_start_xmit(struct sk_buff *skb, struct net_device *de
 
 	if (cf->can_dlc > 0) {
 		data = be32_to_cpup((__be32 *)&cf->data[0]);
-		priv->write(data, &priv->tx_mb->data[0]);
+		priv->write(data, &regs->mb[FLEXCAN_TX_MB].data[0]);
 	}
 	if (cf->can_dlc > 4) {
 		data = be32_to_cpup((__be32 *)&cf->data[4]);
-		priv->write(data, &priv->tx_mb->data[1]);
+		priv->write(data, &regs->mb[FLEXCAN_TX_MB].data[1]);
 	}
 
 	can_put_echo_skb(skb, dev, 0);
 
-	priv->write(can_id, &priv->tx_mb->can_id);
-	priv->write(ctrl, &priv->tx_mb->can_ctrl);
+	priv->write(can_id, &regs->mb[FLEXCAN_TX_MB].can_id);
+	priv->write(ctrl, &regs->mb[FLEXCAN_TX_MB].can_ctrl);
 
 	/* Errata ERR005829 step8:
 	 * Write twice INACTIVE(0x8) code to first MB.
@@ -737,7 +736,7 @@ static inline u64 flexcan_read_reg_iflag_rx(struct flexcan_priv *priv)
 	u32 iflag1, iflag2;
 
 	iflag2 = priv->read(&regs->iflag2) & priv->reg_imask2_default &
-		~FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
+		~FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
 	iflag1 = priv->read(&regs->iflag1) & priv->reg_imask1_default;
 
 	return (u64)iflag2 << 32 | iflag1;
@@ -787,7 +786,7 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 	reg_iflag2 = priv->read(&regs->iflag2);
 
 	/* transmission complete interrupt */
-	if (reg_iflag2 & FLEXCAN_IFLAG_MB(priv->tx_mb_idx)) {
+	if (reg_iflag2 & FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB)) {
 		handled = IRQ_HANDLED;
 		stats->tx_bytes += can_get_echo_skb(dev, 0);
 		stats->tx_packets++;
@@ -795,8 +794,8 @@ static irqreturn_t flexcan_irq(int irq, void *dev_id)
 
 		/* after sending a RTR frame MB is in RX mode */
 		priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
-			    &priv->tx_mb->can_ctrl);
-		priv->write(FLEXCAN_IFLAG_MB(priv->tx_mb_idx), &regs->iflag2);
+			    &regs->mb[FLEXCAN_TX_MB].can_ctrl);
+		priv->write(FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB), &regs->iflag2);
 		netif_wake_queue(dev);
 	}
 
@@ -938,7 +937,7 @@ static int flexcan_chip_start(struct net_device *dev)
 	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(priv->tx_mb_idx);
+		FLEXCAN_MCR_IDAM_C | FLEXCAN_MCR_MAXMB(FLEXCAN_TX_MB);
 
 	if (priv->devtype_data->quirks & FLEXCAN_QUIRK_USE_OFF_TIMESTAMP)
 		reg_mcr &= ~FLEXCAN_MCR_FEN;
@@ -1006,7 +1005,7 @@ static int flexcan_chip_start(struct net_device *dev)
 
 	/* mark TX mailbox as INACTIVE */
 	priv->write(FLEXCAN_MB_CODE_TX_INACTIVE,
-		    &priv->tx_mb->can_ctrl);
+		    &regs->mb[FLEXCAN_TX_MB].can_ctrl);
 
 	/* acceptance mask/acceptance code (accept everything) */
 	priv->write(0x0, &regs->rxgmask);
@@ -1365,11 +1364,9 @@ static int flexcan_probe(struct platform_device *pdev)
 		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP];
 	else
 		priv->tx_mb_reserved = &regs->mb[FLEXCAN_TX_MB_RESERVED_OFF_FIFO];
-	priv->tx_mb_idx = FLEXCAN_TX_MB;
-	priv->tx_mb = &regs->mb[priv->tx_mb_idx];
 
 	priv->reg_imask1_default = 0;
-	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(priv->tx_mb_idx);
+	priv->reg_imask2_default = FLEXCAN_IFLAG_MB(FLEXCAN_TX_MB);
 
 	priv->offload.mailbox_read = flexcan_mailbox_read;