libpayload: Consolidate io vs. mem mapped serial into accessor functions

This way we won't have two copies of the hardware init function, and three
copies of the putchar, havechar, and getchar functions.

Change-Id: Ifda7fec5d582244b0e163ee93ffeedeb28ce48da
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: http://review.coreboot.org/2657
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 49 insertions, 106 deletions

diff --git a/payloads/libpayload/drivers/serial.c b/payloads/libpayload/drivers/serial.c
index cd00a13204..0d26750941 100644
--- a/payloads/libpayload/drivers/serial.c
+++ b/payloads/libpayload/drivers/serial.c
@@ -32,68 +32,61 @@
 #include <libpayload.h>
 
 #define IOBASE lib_sysinfo.serial->baseaddr
-#define MEMBASE (phys_to_virt(lib_sysinfo.serial->baseaddr))
-#define DIVISOR(x) (115200 / x)
+#define MEMBASE (phys_to_virt(IOBASE))
 
-static int serial_io_hardware_is_present = 1;
+static int serial_hardware_is_present = 0;
+static int serial_is_mem_mapped = 0;
 
-#ifdef CONFIG_SERIAL_SET_SPEED
-static void serial_io_hardware_init(int port, int speed, int word_bits, int parity, int stop_bits)
+static uint8_t serial_read_reg(int offset)
 {
-	unsigned char reg;
-
-	/* Disable interrupts. */
-	outb(0, port + 0x01);
-
-	/* Assert RTS and DTR. */
-	outb(3, port + 0x04);
-
-	/* Set the divisor latch. */
-	reg = inb(port + 0x03);
-	outb(reg | 0x80, port + 0x03);
-
-	/* Write the divisor. */
-	outb(DIVISOR(speed) & 0xFF, port);
-	outb(DIVISOR(speed) >> 8 & 0xFF, port + 1);
+	if (serial_is_mem_mapped)
+		return readb(MEMBASE + offset);
+	else
+		return inb(IOBASE + offset);
+}
 
-	/* Restore the previous value of the divisor.
-	 * And set 8 bits per character */
-	outb((reg & ~0x80) | 3, port + 0x03);
+static void serial_write_reg(uint8_t val, int offset)
+{
+	if (serial_is_mem_mapped)
+		writeb(val, MEMBASE + offset);
+	else
+		outb(val, IOBASE + offset);
 }
 
-static void serial_mem_hardware_init(int port, int speed, int word_bits, int parity, int stop_bits)
+#ifdef CONFIG_SERIAL_SET_SPEED
+static void serial_hardware_init(int speed, int word_bits,
+				 int parity, int stop_bits)
 {
 	unsigned char reg;
 
-	/* We will assume 8n1 for now. Does anyone use anything else these days? */
-
 	/* Disable interrupts. */
-	writeb(0, MEMBASE + 0x01);
+	serial_write_reg(0, 0x01);
 
 	/* Assert RTS and DTR. */
-	writeb(3, MEMBASE + 0x04);
+	serial_write_reg(3, 0x04);
 
 	/* Set the divisor latch. */
-	reg = readb(MEMBASE + 0x03);
-	writeb(reg | 0x80, MEMBASE + 0x03);
+	reg = serial_read_reg(0x03);
+	serial_write_reg(reg | 0x80, 0x03);
 
 	/* Write the divisor. */
-	writeb(DIVISOR(speed) & 0xFF, MEMBASE);
-	writeb(DIVISOR(speed) >> 8 & 0xFF, MEMBASE + 1);
+	uint16_t divisor = 115200 / speed;
+	serial_write_reg(divisor & 0xFF, 0x00);
+	serial_write_reg(divisor >> 8, 0x01);
 
 	/* Restore the previous value of the divisor.
 	 * And set 8 bits per character */
-	writeb((reg & ~0x80) | 3, MEMBASE + 0x03);
+	serial_write_reg((reg & ~0x80) | 3, 0x03);
 }
 #endif
 
 static struct console_input_driver consin = {
-	.havekey = serial_havechar,
-	.getchar = serial_getchar
+	.havekey = &serial_havechar,
+	.getchar = &serial_getchar
 };
 
 static struct console_output_driver consout = {
-	.putchar = serial_putchar
+	.putchar = &serial_putchar
 };
 
 void serial_init(void)
@@ -101,94 +94,44 @@ void serial_init(void)
 	if (!lib_sysinfo.serial)
 		return;
 
-#ifdef CONFIG_SERIAL_SET_SPEED
-	if (lib_sysinfo.serial->type == CB_SERIAL_TYPE_MEMORY_MAPPED)
-		serial_mem_hardware_init(IOBASE, CONFIG_SERIAL_BAUD_RATE, 8, 0, 1);
-	else
-		serial_io_hardware_init(IOBASE, CONFIG_SERIAL_BAUD_RATE, 8, 0, 1);
-#endif
-	console_add_input_driver(&consin);
-	console_add_output_driver(&consout);
+	serial_is_mem_mapped =
+		(lib_sysinfo.serial->type == CB_SERIAL_TYPE_MEMORY_MAPPED);
 
-	/* check to see if there's actually serial port h/w */
-	if (lib_sysinfo.ser_ioport) {
-		if( (inb(IOBASE + 0x05)==0xFF) && (inb(IOBASE + 0x06)==0xFF) )
-			serial_io_hardware_is_present = 0;
+	if (!serial_is_mem_mapped && (inb(IOBASE + 0x05) == 0xFF) &&
+			(inb(IOBASE + 0x06) == 0xFF)) {
+		return;
 	}
-}
-
-static void serial_io_putchar(unsigned int c)
-{
-	c &= 0xff;
-	while ((inb(IOBASE + 0x05) & 0x20) == 0) ;
-	outb(c, IOBASE);
-}
 
-static int serial_io_havechar(void)
-{
-	if ( !serial_io_hardware_is_present )
-		return 0;
-	return inb(IOBASE + 0x05) & 0x01;
-}
-
-static int serial_io_getchar(void)
-{
-	if ( !serial_io_hardware_is_present )
-		return -1;
-	while (!serial_io_havechar()) ;
-	return (int)inb(IOBASE);
-}
+	serial_hardware_is_present = 1;
 
-static void serial_mem_putchar(unsigned int c)
-{
-	c &= 0xff;
-	while ((readb(MEMBASE + 0x05) & 0x20) == 0) ;
-	writeb(c, MEMBASE);
-}
-
-static int serial_mem_havechar(void)
-{
-	return readb(MEMBASE + 0x05) & 0x01;
-}
-
-static int serial_mem_getchar(void)
-{
-	while (!serial_mem_havechar()) ;
-	return (int)readb(MEMBASE);
+#ifdef CONFIG_SERIAL_SET_SPEED
+	serial_hardware_init(CONFIG_SERIAL_BAUD_RATE, 8, 0, 1);
+#endif
+	console_add_input_driver(&consin);
+	console_add_output_driver(&consout);
 }
 
-
 void serial_putchar(unsigned int c)
 {
-	if (!lib_sysinfo.serial)
+	if (!serial_hardware_is_present)
 		return;
-
-	if (lib_sysinfo.serial->type == CB_SERIAL_TYPE_MEMORY_MAPPED)
-		serial_mem_putchar(c);
-	else
-		serial_io_putchar(c);
+	while ((serial_read_reg(0x05) & 0x20) == 0) ;
+	serial_write_reg(c, 0x00);
 }
 
 int serial_havechar(void)
 {
-	if (!lib_sysinfo.serial)
+	if (!serial_hardware_is_present)
 		return 0;
-
-	if (lib_sysinfo.ser_base)
-		return serial_mem_havechar();
-	else
-		return serial_io_havechar();
+	return serial_read_reg(0x05) & 0x01;
 }
 
 int serial_getchar(void)
 {
-	if (!lib_sysinfo.serial)
+	if (!serial_hardware_is_present)
 		return -1;
-
-	if (lib_sysinfo.ser_base)
-		return serial_mem_getchar();
-	else
-		return serial_io_getchar();
+	while (!serial_havechar()) ;
+	return serial_read_reg(0x00);
 }
 
 /*  These are thinly veiled vt100 functions used by curses */
@@ -214,7 +157,7 @@ int serial_getchar(void)
 
 static void serial_putcmd(const char *str)
 {
-	while(*str)
+	while (*str)
 		serial_putchar(*(str++));
 }