pl011 uart: Add port_init code

* Add code to initilize the uart port
* Fix uart clock

headers/private/kernel/arch/arm/board/raspberry_pi/board_config.h

@@ -24,8 +24,8 @@
 
 #define BOARD_UART_DEBUG BOARD_UART2_BASE
 
-#define BOARD_UART_CLOCK 125000000
-	/* 125Mhz, strange */
+#define BOARD_UART_CLOCK 3000000
+	/* 3Mhz */
 
 
 #endif /* _BOARD_RASPBERRY_PI_BOARD_CONFIG_H */

headers/private/kernel/arch/arm/uart_pl011.h

@@ -72,6 +72,17 @@
 #define PL011_CR_SIREN	0x0002 // SIR enable
 #define PL011_CR_UARTEN 0x0001 // UART enable
 
+#define PL011_LCRH_SPS		0x80
+#define PL01x_LCRH_WLEN_8	0x60
+#define PL01x_LCRH_WLEN_7	0x40
+#define PL01x_LCRH_WLEN_6	0x20
+#define PL01x_LCRH_WLEN_5	0x00
+#define PL01x_LCRH_FEN		0x10
+#define PL01x_LCRH_STP2		0x08
+#define PL01x_LCRH_EPS		0x04
+#define PL01x_LCRH_PEN		0x02
+#define PL01x_LCRH_BRK		0x01
+
 // TODO: Other PL01x registers + values?
 
 

src/system/boot/platform/raspberrypi_arm/serial.cpp

@@ -89,7 +89,8 @@ serial_init(void)
 	}
 
 	gUARTInfo->init_early();
-	gUARTInfo->init(gUARTInfo->base);
+	gUARTInfo->init_port(gUARTInfo->base, 9600);
+	//gUARTInfo->init(gUARTInfo->base);
 
 	serial_enable();
 

src/system/kernel/arch/arm/uart_pl011.cpp

@@ -31,6 +31,28 @@ read_pl011(addr_t base, uint reg)
 void
 uart_pl011_init_port(addr_t base, uint baud)
 {
+	uint16 clockDiv
+		= (baud > BOARD_UART_CLOCK / 16) ? 8 : 4;
+	uint16 baudDivisor = BOARD_UART_CLOCK * clockDiv / baud;
+		// TODO: Round to closest baud divisor
+	uint16 lcr = PL01x_LCRH_WLEN_8;
+
+	// Disable everything
+	unsigned char originalCR
+		= read_pl011(base, PL011_CR);
+	write_pl011(base, PL011_CR, 0);
+
+	// Set baud divisor
+	write_pl011(base, PL011_FBRD, baudDivisor & 0x3f);
+	write_pl011(base, PL011_IBRD, baudDivisor >> 6);
+
+	// Set LCR
+	write_pl011(base, PL011_LCRH, lcr);
+
+	// Disable auto RTS / CTS in original CR
+	originalCR &= ~(PL011_CR_CTSEN | PL011_CR_RTSEN);
+
+	write_pl011(base, PL011_CR, originalCR);
 }
 
 
@@ -60,12 +82,6 @@ uart_pl011_init(addr_t base)
 
 	while (read_pl011(base, PL01x_FR) & PL01x_FR_BUSY);
 		// Wait for xmit
-
-	// Write baud divider
-	#if 0
-	write_pl011(base, PL011_FBRD, div & 0x3F);
-	write_pl011(base, PL011_IBRD, div >> 6);
-	#endif
 }