drivers: add UART 16550 compatible PCI device support

add support for UART 16550 compatible PCI device.
For now we support qemu serial PCI devices and AX99100 based cards.

Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>

drivers/serial/CMakeLists.txt

@@ -63,4 +63,10 @@ if(CONFIG_UART_BTH4)
   list(APPEND SRCS uart_bth4.c)
 endif()
 
+# UART PCI drivers
+
+if(CONFIG_16550_PCI_UART)
+  list(APPEND SRCS uart_pci_16550.c)
+endif()
+
 target_sources(drivers PRIVATE ${SRCS})

drivers/serial/Kconfig

@@ -79,6 +79,10 @@ if 16550_UART
 source "drivers/serial/Kconfig-16550"
 endif
 
+if PCI
+source "drivers/serial/Kconfig-pci"
+endif
+
 #
 # MCU serial peripheral driver?
 #

drivers/serial/Make.defs

@@ -75,6 +75,12 @@ ifeq ($(CONFIG_RAM_UART),y)
   CSRCS += uart_ram.c
 endif
 
+# UART PCI drivers
+
+ifeq ($(CONFIG_16550_PCI_UART),y)
+  CSRCS += uart_pci_16550.c
+endif
+
 # Include serial build support
 
 DEPPATH += --dep-path serial

include/nuttx/serial/uart_pci_16550.h

@@ -0,0 +1,51 @@
+/****************************************************************************
+ * include/nuttx/serial/uart_pci_16550.h
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+#ifndef __INCLUDE_NUTTX_SERIAL_UART_PCI_16550_H
+#define __INCLUDE_NUTTX_SERIAL_UART_PCI_16550_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+#ifdef CONFIG_16550_PCI_UART
+int pci_u16550_init(void);
+#endif
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __INCLUDE_NUTTX_SERIAL_UART_PCI_16550_H */