[serial] Use new UART abstraction in serial console driver

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

7 files changed, 155 insertions, 282 deletions

diff --git a/src/arch/i386/interface/syslinux/comboot_call.c b/src/arch/i386/interface/syslinux/comboot_call.c
index 1854501d..4d033409 100644
--- a/src/arch/i386/interface/syslinux/comboot_call.c
+++ b/src/arch/i386/interface/syslinux/comboot_call.c
@@ -41,8 +41,6 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #include <ipxe/image.h>
 #include <ipxe/version.h>
 #include <usr/imgmgmt.h>
-#include "config/console.h"
-#include "config/serial.h"
 
 /** The "SYSLINUX" version string */
 static char __bss16_array ( syslinux_version, [32] );
@@ -261,8 +259,10 @@ static __asmcall void int21 ( struct i386_all_regs *ix86 ) {
 		break;
 
 	case 0x04: /* Write Character to Serial Port */
-		serial_putc ( ix86->regs.dl );
-		ix86->flags &= ~CF;
+		if ( serial_console.base ) {
+			uart_transmit ( &serial_console, ix86->regs.dl );
+			ix86->flags &= ~CF;
+		}
 		break;
 
 	case 0x09: /* Write DOS String to Console */
@@ -455,15 +455,12 @@ static __asmcall void int22 ( struct i386_all_regs *ix86 ) {
 		break;
 
 	case 0x000B: /* Get Serial Console Configuration */
-#if defined(CONSOLE_SERIAL) && !defined(COMPRESERVE)
-		ix86->regs.dx = COMCONSOLE;
-		ix86->regs.cx = 115200 / COMSPEED;
-		ix86->regs.bx = 0;
-#else
-		ix86->regs.dx = 0;
-#endif
-
-		ix86->flags &= ~CF;
+		if ( serial_console.base ) {
+			ix86->regs.dx = ( ( intptr_t ) serial_console.base );
+			ix86->regs.cx = serial_console.divisor;
+			ix86->regs.bx = 0;
+			ix86->flags &= ~CF;
+		}
 		break;
 
 	case 0x000E: /* Get configuration file name */
diff --git a/src/config/config.c b/src/config/config.c
index 9cc23949..120a1d4f 100644
--- a/src/config/config.c
+++ b/src/config/config.c
@@ -55,7 +55,7 @@ PROVIDE_REQUIRING_SYMBOL();
 REQUIRE_OBJECT ( bios_console );
 #endif
 #ifdef CONSOLE_SERIAL
-REQUIRE_OBJECT ( serial_console );
+REQUIRE_OBJECT ( serial );
 #endif
 #ifdef CONSOLE_DIRECT_VGA
 REQUIRE_OBJECT ( video_subr );
diff --git a/src/config/serial.h b/src/config/serial.h
index 08368efd..27040dc5 100644
--- a/src/config/serial.h
+++ b/src/config/serial.h
@@ -13,11 +13,6 @@
 
 FILE_LICENCE ( GPL2_OR_LATER );
 
-#define	COM1		0x3f8
-#define	COM2		0x2f8
-#define	COM3		0x3e8
-#define	COM4		0x2e8
-
 #define	COMCONSOLE	COM1		/* I/O port address */
 
 /* Keep settings from a previous user of the serial port (e.g. lilo or
diff --git a/src/core/serial.c b/src/core/serial.c
index 7e4460ab..4ce02551 100644
--- a/src/core/serial.c
+++ b/src/core/serial.c
@@ -1,259 +1,184 @@
 /*
- * The serial port interface routines implement a simple polled i/o
- * interface to a standard serial port.  Due to the space restrictions
- * for the boot blocks, no BIOS support is used (since BIOS requires
- * expensive real/protected mode switches), instead the rudimentary
- * BIOS support is duplicated here.
+ * Copyright (C) 2014 Michael Brown <mbrown@fensystems.co.uk>.
  *
- * The base address and speed for the i/o port are passed from the
- * Makefile in the COMCONSOLE and CONSPEED preprocessor macros.  The
- * line control parameters are currently hard-coded to 8 bits, no
- * parity, 1 stop bit (8N1).  This can be changed in init_serial().
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
  */
 
-FILE_LICENCE ( GPL2_OR_LATER );
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/** @file
+ *
+ * Serial console
+ *
+ */
 
-#include "stddef.h"
+#include <stddef.h>
 #include <ipxe/init.h>
-#include <ipxe/io.h>
-#include <unistd.h>
+#include <ipxe/uart.h>
+#include <ipxe/console.h>
 #include <ipxe/serial.h>
-#include "config/serial.h"
-
-/* Set default values if none specified */
+#include <config/console.h>
+#include <config/serial.h>
 
-#ifndef COMCONSOLE
-#define COMCONSOLE	0x3f8
+/* Set default console usage if applicable */
+#if ! ( defined ( CONSOLE_SERIAL ) && CONSOLE_EXPLICIT ( CONSOLE_SERIAL ) )
+#undef CONSOLE_SERIAL
+#define CONSOLE_SERIAL ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
 #endif
 
-#ifndef COMSPEED
-#define COMSPEED	9600
-#endif
-
-#ifndef COMDATA
-#define COMDATA		8
+/* UART port number */
+#ifdef COMCONSOLE
+#define CONSOLE_PORT COMCONSOLE
+#else
+#define CONSOLE_PORT 0
 #endif
 
-#ifndef COMPARITY
-#define COMPARITY	0
+/* UART baud rate */
+#ifdef COMPRESERVE
+#define CONSOLE_BAUD 0
+#else
+#define CONSOLE_BAUD COMSPEED
 #endif
 
-#ifndef COMSTOP
-#define COMSTOP		1
+/* UART line control register value */
+#ifdef COMPRESERVE
+#define CONSOLE_LCR 0
+#else
+#define CONSOLE_LCR UART_LCR_WPS ( COMDATA, COMPARITY, COMSTOP )
 #endif
 
-#undef UART_BASE
-#define UART_BASE ( COMCONSOLE )
-
-#undef UART_BAUD
-#define UART_BAUD ( COMSPEED )
+/** Serial console UART */
+struct uart serial_console;
 
-#if ((115200%UART_BAUD) != 0)
-#error Bad ttys0 baud rate
-#endif
-
-#define COMBRD (115200/UART_BAUD)
+/**
+ * Print a character to serial console
+ *
+ * @v character		Character to be printed
+ */
+static void serial_putchar ( int character ) {
 
-/* Line Control Settings */
-#define UART_LCS ( ( ( (COMDATA) - 5 )	<< 0 ) | \
-		   ( ( (COMPARITY) )	<< 3 ) | \
-		   ( ( (COMSTOP) - 1 )	<< 2 ) )
+	/* Do nothing if we have no UART */
+	if ( ! serial_console.base )
+		return;
 
-/* Data */
-#define UART_RBR 0x00
-#define UART_TBR 0x00
+	/* Transmit character */
+	uart_transmit ( &serial_console, character );
+}
 
-/* Control */
-#define UART_IER 0x01
-#define UART_IIR 0x02
-#define UART_FCR 0x02
-#define UART_LCR 0x03
-#define UART_MCR 0x04
-#define UART_DLL 0x00
-#define UART_DLM 0x01
+/**
+ * Get character from serial console
+ *
+ * @ret character	Character read from console
+ */
+static int serial_getchar ( void ) {
+	uint8_t data;
 
-/* Status */
-#define UART_LSR 0x05
-#define  UART_LSR_TEMPT 0x40	/* Transmitter empty */
-#define  UART_LSR_THRE  0x20	/* Transmit-hold-register empty */
-#define  UART_LSR_BI	0x10	/* Break interrupt indicator */
-#define  UART_LSR_FE	0x08	/* Frame error indicator */
-#define  UART_LSR_PE	0x04	/* Parity error indicator */
-#define  UART_LSR_OE	0x02	/* Overrun error indicator */
-#define  UART_LSR_DR	0x01	/* Receiver data ready */
+	/* Do nothing if we have no UART */
+	if ( ! serial_console.base )
+		return 0;
 
-#define UART_MSR 0x06
-#define UART_SCR 0x07
+	/* Wait for data to be ready */
+	while ( ! uart_data_ready ( &serial_console ) ) {}
 
-#if defined(UART_MEM)
-#define uart_readb(addr) readb((addr))
-#define uart_writeb(val,addr) writeb((val),(addr))
-#else
-#define uart_readb(addr) inb((addr))
-#define uart_writeb(val,addr) outb((val),(addr))
-#endif
+	/* Receive data */
+	data = uart_receive ( &serial_console );
 
-/* Boolean for the state of serial driver initialization */
-int serial_initialized = 0;
+	/* Strip any high bit and convert DEL to backspace */
+	data &= 0x7f;
+	if ( data == 0x7f )
+		data = 0x08;
 
-/*
- * void serial_putc(int ch);
- *	Write character `ch' to port UART_BASE.
- */
-void serial_putc ( int ch ) {
-	int i;
-	int status;
-	i = 1000; /* timeout */
-	while(--i > 0) {
-		status = uart_readb(UART_BASE + UART_LSR);
-		if (status & UART_LSR_THRE) { 
-			/* TX buffer emtpy */
-			uart_writeb(ch, UART_BASE + UART_TBR);
-			break;
-		}
-		mdelay(2);
-	}
+	return data;
 }
 
-/*
- * int serial_getc(void);
- *	Read a character from port UART_BASE.
- */
-int serial_getc ( void ) {
-	int status;
-	int ch;
-	do {
-		status = uart_readb(UART_BASE + UART_LSR);
-	} while((status & 1) == 0);
-	ch = uart_readb(UART_BASE + UART_RBR);	/* fetch (first) character */
-	ch &= 0x7f;				/* remove any parity bits we get */
-	if (ch == 0x7f) {			/* Make DEL... look like BS */
-		ch = 0x08;
-	}
-	return ch;
-}
-
-/*
- * int serial_ischar(void);
- *       If there is a character in the input buffer of port UART_BASE,
- *       return nonzero; otherwise return 0.
+/**
+ * Check for character ready to read from serial console
+ *
+ * @ret True		Character available to read
+ * @ret False		No character available to read
  */
-int serial_ischar ( void ) {
-	int status;
-	status = uart_readb(UART_BASE + UART_LSR);	/* line status reg; */
-	return status & 1;		/* rx char available */
-}
+static int serial_iskey ( void ) {
 
-/*
- * int serial_init(void);
- *	Initialize port UART_BASE to speed COMSPEED, line settings 8N1.
- */
-static void serial_init ( void ) {
-	int status;
-	int divisor, lcs;
+	/* Do nothing if we have no UART */
+	if ( ! serial_console.base )
+		return 0;
 
-	DBG ( "Serial port %#x initialising\n", UART_BASE );
+	/* Check UART */
+	return uart_data_ready ( &serial_console );
+}
 
-	divisor = COMBRD;
-	lcs = UART_LCS;
+/** Serial console */
+struct console_driver serial_console_driver __console_driver = {
+	.putchar = serial_putchar,
+	.getchar = serial_getchar,
+	.iskey = serial_iskey,
+	.usage = CONSOLE_SERIAL,
+};
 
+/** Initialise serial console */
+static void serial_init ( void ) {
+	int rc;
 
-#ifdef COMPRESERVE
-	lcs = uart_readb(UART_BASE + UART_LCR) & 0x7f;
-	uart_writeb(0x80 | lcs, UART_BASE + UART_LCR);
-	divisor = (uart_readb(UART_BASE + UART_DLM) << 8) | uart_readb(UART_BASE + UART_DLL);
-	uart_writeb(lcs, UART_BASE + UART_LCR);
-#endif
+	/* Do nothing if we have no default port */
+	if ( ! CONSOLE_PORT )
+		return;
 
-	/* Set Baud Rate Divisor to COMSPEED, and test to see if the
-	 * serial port appears to be present.
-	 */
-	uart_writeb(0x80 | lcs, UART_BASE + UART_LCR);
-	uart_writeb(0xaa, UART_BASE + UART_DLL);
-	if (uart_readb(UART_BASE + UART_DLL) != 0xaa) {
-		DBG ( "Serial port %#x UART_DLL failed\n", UART_BASE );
-		goto out;
-	}
-	uart_writeb(0x55, UART_BASE + UART_DLL);
-	if (uart_readb(UART_BASE + UART_DLL) != 0x55) {
-		DBG ( "Serial port %#x UART_DLL failed\n", UART_BASE );
-		goto out;
+	/* Select UART */
+	if ( ( rc = uart_select ( &serial_console, CONSOLE_PORT ) ) != 0 ) {
+		DBG ( "Could not select UART %d: %s\n",
+		      CONSOLE_PORT, strerror ( rc ) );
+		return;
 	}
-	uart_writeb(divisor & 0xff, UART_BASE + UART_DLL);
-	if (uart_readb(UART_BASE + UART_DLL) != (divisor & 0xff)) {
-		DBG ( "Serial port %#x UART_DLL failed\n", UART_BASE );
-		goto out;
-	}
-	uart_writeb(0xaa, UART_BASE + UART_DLM);
-	if (uart_readb(UART_BASE + UART_DLM) != 0xaa) {
-		DBG ( "Serial port %#x UART_DLM failed\n", UART_BASE );
-		goto out;
-	}
-	uart_writeb(0x55, UART_BASE + UART_DLM);
-	if (uart_readb(UART_BASE + UART_DLM) != 0x55) {
-		DBG ( "Serial port %#x UART_DLM failed\n", UART_BASE );
-		goto out;
-	}
-	uart_writeb((divisor >> 8) & 0xff, UART_BASE + UART_DLM);
-	if (uart_readb(UART_BASE + UART_DLM) != ((divisor >> 8) & 0xff)) {
-		DBG ( "Serial port %#x UART_DLM failed\n", UART_BASE );
-		goto out;
-	}
-	uart_writeb(lcs, UART_BASE + UART_LCR);
-	
-	/* disable interrupts */
-	uart_writeb(0x0, UART_BASE + UART_IER);
 
-	/* enable fifos */
-	uart_writeb(0x01, UART_BASE + UART_FCR);
+	/* Initialise UART */
+	if ( ( rc = uart_init ( &serial_console, CONSOLE_BAUD,
+				CONSOLE_LCR ) ) != 0 ) {
+		DBG ( "Could not initialise UART %d baud %d LCR %#02x: %s\n",
+		      CONSOLE_PORT, CONSOLE_BAUD, CONSOLE_LCR, strerror ( rc ));
+		return;
+	}
+}
 
-	/* Set clear to send, so flow control works... */
-	uart_writeb((1<<1), UART_BASE + UART_MCR);
+/**
+ * Shut down serial console
+ *
+ * @v flags		Shutdown flags
+ */
+static void serial_shutdown ( int flags __unused ) {
 
-	/* Flush the input buffer. */
-	do {
-		/* rx buffer reg
-		 * throw away (unconditionally the first time)
-		 */
-	        (void) uart_readb(UART_BASE + UART_RBR);
-		/* line status reg */
-		status = uart_readb(UART_BASE + UART_LSR);
-	} while(status & UART_LSR_DR);
+	/* Do nothing if we have no UART */
+	if ( ! serial_console.base )
+		return;
 
-	/* Note that serial support has been initialized */
-	serial_initialized = 1;
- out:
-	return;
-}
+	/* Flush any pending output */
+	uart_flush ( &serial_console );
 
-/*
- * void serial_fini(void);
- *	Cleanup our use of the serial port, in particular flush the
- *	output buffer so we don't accidentially lose characters.
- */
-static void serial_fini ( int flags __unused ) {
-	int i, status;
-	/* Flush the output buffer to avoid dropping characters,
-	 * if we are reinitializing the serial port.
-	 */
-	i = 10000; /* timeout */
-	do {
-		status = uart_readb(UART_BASE + UART_LSR);
-	} while((--i > 0) && !(status & UART_LSR_TEMPT));
-	/* Don't mark it as disabled; it's still usable */
+	/* Leave console enabled; it's still usable */
 }
 
-/**
- * Serial driver initialisation function
- *
- * Initialise serial port early on so that it is available to capture
- * early debug messages.
- */
-struct init_fn serial_init_fn __init_fn ( INIT_SERIAL ) = {
+/** Serial console initialisation function */
+struct init_fn serial_console_init_fn __init_fn ( INIT_CONSOLE ) = {
 	.initialise = serial_init,
 };
 
-/** Serial driver startup function */
+/** Serial console startup function */
 struct startup_fn serial_startup_fn __startup_fn ( STARTUP_EARLY ) = {
-	.shutdown = serial_fini,
+	.shutdown = serial_shutdown,
 };
diff --git a/src/core/serial_console.c b/src/core/serial_console.c
deleted file mode 100644
index de9b84ca..00000000
--- a/src/core/serial_console.c
+++ /dev/null
@@ -1,42 +0,0 @@
-#include <ipxe/init.h>
-#include <ipxe/serial.h>
-#include <ipxe/console.h>
-#include <config/console.h>
-
-/** @file
- *
- * Serial console
- *
- */
-
-/* Set default console usage if applicable */
-#if ! ( defined ( CONSOLE_SERIAL ) && CONSOLE_EXPLICIT ( CONSOLE_SERIAL ) )
-#undef CONSOLE_SERIAL
-#define CONSOLE_SERIAL ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_LOG )
-#endif
-
-struct console_driver serial_console __console_driver;
-
-static void serial_console_init ( void ) {
-	/*
-	 * Check if serial driver initialization is done.
-	 * If so, it's time to enable the serial console.
-	 */
-	if ( serial_initialized )
-		serial_console.disabled = 0;
-}
-
-struct console_driver serial_console __console_driver = {
-	.putchar = serial_putc,
-	.getchar = serial_getc,
-	.iskey = serial_ischar,
-	.disabled = CONSOLE_DISABLED,
-	.usage = CONSOLE_SERIAL,
-};
-
-/**
- * Serial console initialisation function
- */
-struct init_fn serial_console_init_fn __init_fn ( INIT_CONSOLE ) = {
-	.initialise = serial_console_init,
-};
diff --git a/src/include/ipxe/init.h b/src/include/ipxe/init.h
index e051dc6c..025cfaf3 100644
--- a/src/include/ipxe/init.h
+++ b/src/include/ipxe/init.h
@@ -26,10 +26,9 @@ struct init_fn {
  */
 
 #define INIT_EARLY	01	/**< Early initialisation */
-#define INIT_SERIAL	02	/**< Serial driver initialisation */
-#define	INIT_CONSOLE	03	/**< Console initialisation */
-#define INIT_NORMAL	04	/**< Normal initialisation */
-#define INIT_LATE	05	/**< Late initialisation */
+#define	INIT_CONSOLE	02	/**< Console initialisation */
+#define INIT_NORMAL	03	/**< Normal initialisation */
+#define INIT_LATE	04	/**< Late initialisation */
 
 /** @} */
 
diff --git a/src/include/ipxe/serial.h b/src/include/ipxe/serial.h
index 86d05370..83be59c3 100644
--- a/src/include/ipxe/serial.h
+++ b/src/include/ipxe/serial.h
@@ -3,15 +3,14 @@
 
 /** @file
  *
- * Serial driver functions
+ * Serial console
  *
  */
 
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
-extern void serial_putc ( int ch );
-extern int serial_getc ( void );
-extern int serial_ischar ( void );
-extern int serial_initialized;
+#include <ipxe/uart.h>
+
+extern struct uart serial_console;
 
 #endif /* _IPXE_SERIAL_H */