[PATCH 6/6] tty: serial: 8250: Add support for MUEX50 UART

[Crescent Hsieh]

The MUEX50 UART does not directly match to PORT_16550A or other generic
UART configurations.

This patch adds an UART configuration to capture the hardware
capabilities of MUEX50 UART and apply to Moxa PCI serial boards.

Signed-off-by: Crescent Hsieh <crescentcy.hsieh@xxxxxxxx>
---
 drivers/tty/serial/8250/8250_pci.c  | 3 +++
 drivers/tty/serial/8250/8250_port.c | 8 ++++++++
 include/uapi/linux/serial_core.h    | 3 +++
 3 files changed, 14 insertions(+)

diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index e2fcddec9ab5..3ccbb406f505 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -2159,6 +2159,9 @@ pci_moxa_setup(struct serial_private *priv,
 	unsigned int bar = FL_GET_BASE(board->flags);
 	int offset;
 
+	port->port.flags |= UPF_FIXED_TYPE;
+	port->port.type = PORT_MUEX50;
+
 	if (pci_moxa_is_pcie(dev->device) || pci_moxa_is_mini_pcie(dev->device)) {
 		if (pci_moxa_supported_rs(dev) & MOXA_SUPP_RS485) {
 			port->port.rs485_config = pci_moxa_rs485_config;
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 893bc493f662..c3de350e9a30 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -319,6 +319,14 @@ static const struct serial8250_config uart_config[] = {
 		.rxtrig_bytes	= {1, 8, 16, 30},
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
+	[PORT_MUEX50] = {
+		.name		= "Moxa PCIe UART",
+		.fifo_size	= 128,
+		.tx_loadsz	= 128,
+		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 4, 8, 14},
+		.flags		= UART_CAP_FIFO,
+	},
 };
 
 /* Uart divisor latch read */
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 9c007a106330..5afeb6d99e7e 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -231,6 +231,9 @@
 /* Sunplus UART */
 #define PORT_SUNPLUS	123
 
+/* Moxa PCIe UART */
+#define PORT_MUEX50	124
+
 /* Generic type identifier for ports which type is not important to userspace. */
 #define PORT_GENERIC	(-1)
 
-- 
2.34.1