serial: exar: add optional board_init function

Add an optional "board_init()" function pointer to struct exar8250_board
which is called once during probe prior to setting up the ports. It will
be used in subsequent patches of this series.

Signed-off-by: Parker Newman <[email protected]>
Link: https://lore.kernel.org/r/0e72a3154114c733283ff273bc1e31456ee101f4.1713382717.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: pnewman-cti

drivers/tty/serial/8250/8250_exar.c

@@ -177,12 +177,14 @@ struct exar8250_platform {
  * struct exar8250_board - board information
  * @num_ports: number of serial ports
  * @reg_shift: describes UART register mapping in PCI memory
- * @setup: quirk run at ->probe() stage
+ * @board_init: quirk run once at ->probe() stage before setting up ports
+ * @setup: quirk run at ->probe() stage for each port
  * @exit: quirk run at ->remove() stage
  */
 struct exar8250_board {
 	unsigned int num_ports;
 	unsigned int reg_shift;
+	int     (*board_init)(struct exar8250 *priv, struct pci_dev *pcidev);
 	int	(*setup)(struct exar8250 *, struct pci_dev *,
 			 struct uart_8250_port *, int);
 	void	(*exit)(struct pci_dev *pcidev);
@@ -773,6 +775,15 @@ exar_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *ent)
 	if (rc)
 		return rc;
 
+	if (board->board_init) {
+		rc = board->board_init(priv, pcidev);
+		if (rc) {
+			dev_err_probe(&pcidev->dev, rc,
+					"failed to init serial board\n");
+			return rc;
+		}
+	}
+
 	for (i = 0; i < nr_ports && i < maxnr; i++) {
 		rc = board->setup(priv, pcidev, &uart, i);
 		if (rc) {