From: Michael Brown <mcb30@ipxe.org>
Date: Sat, 21 Jun 2025 22:11:56 +0000 (+0100)
Subject: [uart] Allow for dynamically registered 16550 UARTs
X-Git-Url: http://git.ipfire.org/gitweb/gitweb.cgi?a=commitdiff_plain;h=cca1cfd49ec3ac0ada90197d11118a99d16aed5b;p=thirdparty%2Fipxe.git

[uart] Allow for dynamically registered 16550 UARTs

Use the generic UART driver-private data pointer, rather than
embedding the generic UART within the 16550 UART structure.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/arch/x86/core/x86_uart.c b/src/arch/x86/core/x86_uart.c
index 2580b931b..a1d643a58 100644
--- a/src/arch/x86/core/x86_uart.c
+++ b/src/arch/x86/core/x86_uart.c
@@ -35,13 +35,14 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 /** Define a fixed ISA UART */
 #define ISA_UART( NAME, BASE )						\
-	struct ns16550_uart NAME = {					\
-		.uart = {						\
-			.refcnt = REF_INIT ( ref_no_free ),		\
-			.name = #NAME,					\
-			.op = &ns16550_operations,			\
-		},							\
+	static struct ns16550_uart ns16550_ ## NAME = {			\
 		.base = ( ( void * ) (BASE) ),				\
+	};								\
+	struct uart NAME = {						\
+		.refcnt = REF_INIT ( ref_no_free ),			\
+		.name = #NAME,						\
+		.op = &ns16550_operations,				\
+		.priv = &ns16550_ ## NAME,				\
 	}
 
 /* Fixed ISA UARTs */
diff --git a/src/arch/x86/include/bits/ns16550.h b/src/arch/x86/include/bits/ns16550.h
index 9f7d741ae..cc2bd84c1 100644
--- a/src/arch/x86/include/bits/ns16550.h
+++ b/src/arch/x86/include/bits/ns16550.h
@@ -46,15 +46,15 @@ ns16550_read ( struct ns16550_uart *ns16550, unsigned int address ) {
 #define COM4_BASE 0x2e8
 
 /* Fixed ISA serial ports */
-extern struct ns16550_uart com1;
-extern struct ns16550_uart com2;
-extern struct ns16550_uart com3;
-extern struct ns16550_uart com4;
+extern struct uart com1;
+extern struct uart com2;
+extern struct uart com3;
+extern struct uart com4;
 
 /* Fixed ISA serial port names */
-#define COM1 &com1.uart
-#define COM2 &com2.uart
-#define COM3 &com3.uart
-#define COM4 &com4.uart
+#define COM1 &com1
+#define COM2 &com2
+#define COM3 &com3
+#define COM4 &com4
 
 #endif /* _BITS_NS16550_H */
diff --git a/src/arch/x86/interface/syslinux/comboot_call.c b/src/arch/x86/interface/syslinux/comboot_call.c
index 97bdaeae3..c3e921075 100644
--- a/src/arch/x86/interface/syslinux/comboot_call.c
+++ b/src/arch/x86/interface/syslinux/comboot_call.c
@@ -447,9 +447,7 @@ static __asmcall __used void int22 ( struct i386_all_regs *ix86 ) {
 
 	case 0x000B: /* Get Serial Console Configuration */
 		if ( serial_console ) {
-			struct ns16550_uart *comport =
-				container_of ( serial_console,
-					       struct ns16550_uart, uart );
+			struct ns16550_uart *comport = serial_console->priv;
 
 			ix86->regs.dx = ( ( intptr_t ) comport->base );
 			ix86->regs.cx = comport->divisor;
diff --git a/src/drivers/uart/ns16550.c b/src/drivers/uart/ns16550.c
index 58a71261b..cf8c744c6 100644
--- a/src/drivers/uart/ns16550.c
+++ b/src/drivers/uart/ns16550.c
@@ -47,8 +47,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  * @v data		Data
  */
 static void ns16550_transmit ( struct uart *uart, uint8_t data ) {
-	struct ns16550_uart *ns16550 =
-		container_of ( uart, struct ns16550_uart, uart );
+	struct ns16550_uart *ns16550 = uart->priv;
 	unsigned int i;
 	uint8_t lsr;
 
@@ -71,8 +70,7 @@ static void ns16550_transmit ( struct uart *uart, uint8_t data ) {
  * @ret ready		Data is ready
  */
 static int ns16550_data_ready ( struct uart *uart ) {
-	struct ns16550_uart *ns16550 =
-		container_of ( uart, struct ns16550_uart, uart );
+	struct ns16550_uart *ns16550 = uart->priv;
 	uint8_t lsr;
 
 	/* Check for receive data ready */
@@ -87,8 +85,7 @@ static int ns16550_data_ready ( struct uart *uart ) {
  * @ret data		Data
  */
 static uint8_t ns16550_receive ( struct uart *uart ) {
-	struct ns16550_uart *ns16550 =
-		container_of ( uart, struct ns16550_uart, uart );
+	struct ns16550_uart *ns16550 = uart->priv;
 	uint8_t rbr;
 
 	/* Receive byte */
@@ -102,8 +99,7 @@ static uint8_t ns16550_receive ( struct uart *uart ) {
  * @v uart		UART
  */
 static void ns16550_flush ( struct uart *uart ) {
-	struct ns16550_uart *ns16550 =
-		container_of ( uart, struct ns16550_uart, uart );
+	struct ns16550_uart *ns16550 = uart->priv;
 	unsigned int i;
 	uint8_t lsr;
 
@@ -123,8 +119,7 @@ static void ns16550_flush ( struct uart *uart ) {
  * @ret rc		Return status code
  */
 static int ns16550_init ( struct uart *uart, unsigned int baud ) {
-	struct ns16550_uart *ns16550 =
-		container_of ( uart, struct ns16550_uart, uart );
+	struct ns16550_uart *ns16550 = uart->priv;
 	uint8_t dlm;
 	uint8_t dll;
 
diff --git a/src/include/ipxe/ns16550.h b/src/include/ipxe/ns16550.h
index 3aaab6891..6699205e2 100644
--- a/src/include/ipxe/ns16550.h
+++ b/src/include/ipxe/ns16550.h
@@ -78,8 +78,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 /** A 16550-compatible UART */
 struct ns16550_uart {
-	/** Generic UART */
-	struct uart uart;
 	/** Register base address */
 	void *base;
 	/** Register shift */