can: mcp251xfd: introduce and make use of mcp251xfd_is_fd_mode()

This patch replaces the open coded check, if the chip's FIFOs are
configured for CAN-FD mode, by the newly introduced function
mcp251xfd_is_fd_mode().

Link: https://lore.kernel.org/all/20220105154300.1258636-14-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/spi/mcp251xfd/mcp251xfd-chip-fifo.c

@@ -34,7 +34,7 @@ mcp251xfd_chip_rx_fifo_init_one(const struct mcp251xfd_priv *priv,
 		MCP251XFD_REG_FIFOCON_RXOVIE |
 		MCP251XFD_REG_FIFOCON_TFNRFNIE;
 
-	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD))
+	if (mcp251xfd_is_fd_mode(priv))
 		fifo_con |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
 				       MCP251XFD_REG_FIFOCON_PLSIZE_64);
 	else
@@ -84,7 +84,7 @@ int mcp251xfd_chip_fifo_init(const struct mcp251xfd_priv *priv)
 		MCP251XFD_REG_FIFOCON_TXEN |
 		MCP251XFD_REG_FIFOCON_TXATIE;
 
-	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD))
+	if (mcp251xfd_is_fd_mode(priv))
 		val |= FIELD_PREP(MCP251XFD_REG_FIFOCON_PLSIZE_MASK,
 				  MCP251XFD_REG_FIFOCON_PLSIZE_64);
 	else

drivers/net/can/spi/mcp251xfd/mcp251xfd-ring.c

@@ -209,8 +209,7 @@ int mcp251xfd_ring_alloc(struct mcp251xfd_priv *priv)
 	int ram_free, i;
 
 	tef_obj_size = sizeof(struct mcp251xfd_hw_tef_obj);
-	/* listen-only mode works like FD mode */
-	if (priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD)) {
+	if (mcp251xfd_is_fd_mode(priv)) {
 		tx_obj_num = MCP251XFD_TX_OBJ_NUM_CANFD;
 		tx_obj_size = sizeof(struct mcp251xfd_hw_tx_obj_canfd);
 		rx_obj_size = sizeof(struct mcp251xfd_hw_rx_obj_canfd);

drivers/net/can/spi/mcp251xfd/mcp251xfd.h

@@ -626,6 +626,12 @@ MCP251XFD_IS(2517);
 MCP251XFD_IS(2518);
 MCP251XFD_IS(251X);
 
+static inline bool mcp251xfd_is_fd_mode(const struct mcp251xfd_priv *priv)
+{
+	/* listen-only mode works like FD mode */
+	return priv->can.ctrlmode & (CAN_CTRLMODE_LISTENONLY | CAN_CTRLMODE_FD);
+}
+
 static inline u8 mcp251xfd_first_byte_set(u32 mask)
 {
 	return (mask & 0x0000ffff) ?