first and last commit

drivers/uart/16x50/16x50.c

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+/* -*- tab-width: 8; Mode: C; c-basic-offset: 8; indent-tabs-mode: t -*-
+ *
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * This document is the property of Apple Inc.
+ * It is considered confidential and proprietary.
+ *
+ * This document may not be reproduced or transmitted in any form,
+ * in whole or in part, without the express written permission of
+ * Apple Inc.
+ */
+
+#include <debug.h>
+#include <drivers/uart.h>
+#include <platform/soc/hwclocks.h>
+#include <platform/soc/hwregbase.h>
+
+#include "16x50.h"
+
+static const uint32_t uart_ports[] = {
+#ifdef  UART0_BASE_ADDR
+	UART0_BASE_ADDR,
+# ifdef UART1_BASE_ADDR
+	UART1_BASE_ADDR,
+# endif
+#else
+# error No UARTs configured
+#endif
+};
+
+/*
+ * uart_hw_init
+ *
+ * Initialise the port for the requested baudrate.
+ */
+int
+uart_hw_init(uint32_t port, uint32_t baudrate)
+{
+	return(uart_hw_init_extended(port, baudrate, 8, PARITY_NONE, 1));
+}
+
+int
+uart_hw_init_extended(uint32_t port,
+		      uint32_t baudrate,
+		      uint32_t databits,
+		      enum uart_parity parity,
+		      uint32_t stopbits)
+{
+	uint32_t	divisor;
+	uint8_t		rv;
+
+	/* wait for the UART to be idle before talking to it */
+	while (!(rLSR(port) & LSR_THRE))
+		;
+
+	/* this can happen if the plaform defines more ports than the target */
+	if (port >= sizeof(uart_ports) / sizeof(uart_ports[0]))
+		return(-1);
+
+	/* disable interrupts, we poll */
+	rIER(port) = 0;	
+
+	/* compute LCR */
+	rv = LCR_WLS_8;
+	switch(parity) {
+	case PARITY_EVEN:
+		rv |= LCR_PEN | LCR_EPS;
+		break;
+	case PARITY_ODD:
+		rv |= LCR_PEN;
+		break;
+	default:
+		break;
+	}
+	switch(stopbits) {
+	default:
+	case 1:
+		rv |= LCR_1_STB;
+		break;
+	case 2:
+		rv |= LCR_2_STB;
+		break;
+	}
+
+	divisor = clock_get_frequency(CLK_UART) / (baudrate * 16);
+	rLCR(port) = rv | LCR_DLAB;	/* enable the divisor latch */	
+	rDLL(port) = divisor & 0xff;
+	rDLM(port) = (divisor >> 8) & 0xff;
+	rLCR(port) = rv;		/* disable the divisor latch */
+	
+	/* reset & re-enble FIFO with trigger at 1 byte */
+	rFCR(port) = FCR_FIFO_EN | FCR_RXSR | FCR_TXSR | FCR_TL1;
+	
+	return(0);
+}
+
+int
+uart_hw_set_rx_buf(uint32_t port, bool interrupt, size_t buffer_len)
+{
+	/* optional interface not implemented */
+	return -1;
+}
+
+/*
+ * uart_hw_getc
+ *
+ * Get a byte from the port.  Returns -1 if there isn't one ready.
+ */
+int
+uart_hw_getc(uint32_t port)
+{
+	ASSERT((unsigned)port < (sizeof(uart_ports) / sizeof(uart_ports[0])));
+
+	/* if data ready, return it */
+	if (rLSR(port) & LSR_DR)
+		return(rRBR(port));
+	return(-1);
+}
+
+/*
+ * uart_hw_putc
+ *
+ * Write a byte to the port.
+ */
+int
+uart_hw_putc(uint32_t port, char c)
+{
+
+	ASSERT((unsigned)port < (sizeof(uart_ports) / sizeof(uart_ports[0])));
+
+	/* if we can send the byte, do it */
+	if (rLSR(port) & LSR_THRE) {
+		rTHR(port) = c;
+		return(0);
+	}
+
+	/* can't send now, caller will yield and retry */
+	return(-1);
+}

drivers/uart/16x50/16x50.h

@@ -0,0 +1,95 @@
+/* -*- tab-width: 8; Mode: C; c-basic-offset: 8; indent-tabs-mode: t -*-
+ *
+ * Copyright (C) 2010 Apple Inc. All rights reserved.
+ *
+ * This document is the property of Apple Computer, Inc.
+ * It is considered confidential and proprietary.
+ *
+ * This document may not be reproduced or transmitted in any form,
+ * in whole or in part, without the express written permission of
+ * Apple Computer, Inc.
+ */
+
+/*
+ * Register layout for a memory-mapped 16x50-style UART.
+ *
+ * Register and bit names/definitions from the National Semiconductor PC16550D datasheet.
+ *
+ * Note that the register set described here is a subset containing just those registers
+ * useful for the iBoot environment.  In particular, no modem support registers/definitions
+ * are included.
+ */
+
+#ifndef __UART_16x50_H
+#define __UART_16x50_H
+
+/* allow an override of the spacing between registers */
+#ifndef UART16x50_REGISTER_STRIDE
+# define UART16x50_REGISTER_STRIDE	4
+#endif
+
+/* allow an override of the datatype used for reading/writing the registers */
+#ifndef UART16x50_REGISTER_TYPE
+# define UART16x50_REGISTER_TYPE	uint32_t
+#endif
+
+/* produce a pointer to a UART register, assuming base registers in uart_ports */
+#define UART_REG(_port, _offset) \
+	(*(volatile UART16x50_REGISTER_TYPE *)((uint8_t *)uart_ports[(_port)] + ((_offset) * UART16x50_REGISTER_STRIDE)))
+
+//
+// UART Registers for UART _port
+//
+#define rRBR(_port)	UART_REG(_port, 0)	// receiver buffer register (RO)
+#define rTHR(_port)	UART_REG(_port, 0)	// transmitter holding register (WO)
+#define rIER(_port)	UART_REG(_port, 1)	// interrupt enable register
+#define rIIR(_port)	UART_REG(_port, 2)	// interrupt ident. register (RO)
+#define rFCR(_port)	UART_REG(_port, 2)	// FIFO control register (WO)
+#define rLCR(_port)	UART_REG(_port, 3)	// line control register 
+#define rLSR(_port)	UART_REG(_port, 5)	// line status register
+#define rDLL(_port)	UART_REG(_port, 0)	// divisor latch (LS)
+#define rDLM(_port)	UART_REG(_port, 1)	// divisor latch (MS)
+
+// IER
+#define IER_ERBFI	(1<<0)			// enable received data available interrupt
+#define IER_ETBEI	(1<<1)			// enable transmit holding register empty interrupt
+#define IER_ELSI	(1<<2)			// enable receiver line status interrupt
+
+// IIR
+#define IIR_NOTPEND	(1<<0)			// interrupt not pending
+#define IIR_IID_MASK	0xe			// interrupt pending/ID mask
+#define IIR_IID_THRE	0x2			// transmitter holding register empty
+#define IIR_IID_RBF	0x4			// received data available
+#define IIR_IID_LSR	0x6			// receiver line status
+#define IIR_IID_CTI	0xc			// character timeout indication
+
+// FCR
+#define FCR_FIFO_EN	(1<<0)			// FIFO enable
+#define FCR_RXSR	(1<<1)			// reciever fifo reset
+#define FCR_TXSR	(1<<2)			// transmitter fifo reset
+#define FCR_TL1		(0<<6)			// RCVR FIFO trigger level - 1 byte
+#define FCR_TL4		(1<<6)			// 4 bytes
+#define FCR_TL8		(2<<6)			// 8 bytes
+#define FCR_TL14	(3<<6)			// 14 bytes
+
+// LCR
+#define LCR_WLS_8	(3<<0)			// 8 bit data (seriously, who uses anything else?)
+#define LCR_1_STB	(0<<2)			// 1 stop bit
+#define LCR_2_STB	(1<<2)			// 2 stop bits
+#define LCR_PEN		(1<<3)			// parity enable
+#define LCR_EPS		(1<<4)			// even parity select
+#define LCR_STICK	(1<<5)			// stick parity
+#define LCR_SBRK	(1<<6)			// set break
+#define LCR_DLAB	(1<<7)			// divisor latch access bit
+
+// LSR
+#define LSR_DR		(1<<0)			// data ready 
+#define LSR_OE		(1<<1)			// overrun 
+#define LSR_PE		(1<<2)			// parity error 
+#define LSR_FE		(1<<3)			// framing error 
+#define LSR_BI		(1<<4)			// break 
+#define LSR_THRE	(1<<5)			// transmit holding register empty 
+#define LSR_TEMT	(1<<6)			// transmitter empty 
+#define LSR_RFERR	(1<<7)			// error in receiver FIFO
+
+#endif /* __UART_16x50_H */

drivers/uart/16x50/rules.mk

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+# Copyright (C) 2010 Apple Computer, Inc. All rights reserved.
+#
+# This document is the property of Apple Computer, Inc.
+# It is considered confidential and proprietary.
+#
+# This document may not be reproduced or transmitted in any form,
+# in whole or in part, without the express written permission of
+# Apple Computer, Inc.
+#
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+MODULES	+=	drivers/uart
+
+OPTIONS += 	WITH_UART_16X50=1 \
+		WITH_HW_UART=1
+
+ALL_OBJS += 	$(LOCAL_DIR)/16x50.o
+

drivers/uart/rules.mk

@@ -0,0 +1,17 @@
+# Copyright (C) 2009 Apple Computer, Inc. All rights reserved.
+#
+# This document is the property of Apple Computer, Inc.
+# It is considered confidential and proprietary.
+#
+# This document may not be reproduced or transmitted in any form,
+# in whole or in part, without the express written permission of
+# Apple Computer, Inc.
+#
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+OPTIONS += \
+	WITH_UART=1
+
+ALL_OBJS += \
+	$(LOCAL_DIR)/uart.o
+

drivers/uart/uart.c

@@ -0,0 +1,157 @@
+/*
+ * Copyright (C) 2009 Apple Inc. All rights reserved.
+ *
+ * This document is the property of Apple Inc.
+ * It is considered confidential and proprietary.
+ *
+ * This document may not be reproduced or transmitted in any form,
+ * in whole or in part, without the express written permission of
+ * Apple Inc.
+ */
+
+#include <debug.h>
+#include <sys/task.h>
+#include <sys.h>
+
+#include <drivers/power.h>
+#include <drivers/uart.h>
+
+#include <target/uartconfig.h>
+
+/*
+ * Hardware-independent UART support.
+ */
+
+#define	UART_BAUDRATE	115200
+
+static int uart_reader_task(void *arg);
+
+/*
+ * uart_init
+ *
+ * Initalise UARTs in the system.
+ *
+ * Starts the debug input polling threads as well.
+ */
+int
+uart_init(void)
+{
+	u_int32_t	port;
+
+	/* do base hardware init */
+	for (port = 0; port < UARTS_COUNT; port++)
+		uart_hw_init(port, UART_BAUDRATE);
+
+#ifdef DEBUG_SERIAL_PORT
+	/* regular console port */
+	task_start(task_create("uart reader", uart_reader_task, (void *)DEBUG_SERIAL_PORT, 0x200));
+#ifdef DEBUG_SERIAL_PORT2
+	/* alternate console port */
+	task_start(task_create("uart reader", uart_reader_task, (void *)DEBUG_SERIAL_PORT2, 0x200));
+#endif
+#endif
+
+#if DEBUG_UART_ENABLE_DEFAULT
+	/* enable console ports early */
+	DebugUartReady |= kPowerNVRAMiBootDebugIAPSerial | kPowerNVRAMiBootDebugAltSerial;
+#endif
+
+	return(0);
+}
+
+/*
+ * uart_getc
+ *
+ * Read a byte from the port, optionally waiting.
+ * If not waiting, returns -1 if a byte is not available.
+ */
+int
+uart_getc(int port, bool wait)
+{
+	int c;
+	
+	for (;;) {
+		/* grab a byte */
+		c = uart_hw_getc(port);
+
+		/* if we got one, or we're not waiting, return */
+		if ((-1 != c) || !wait)
+			return(c);
+
+		/* give up cycles */
+		task_yield();
+	}
+}
+
+/*
+ * uart_puts
+ *
+ * Write a nul-terminated string to the port.
+ */
+int
+uart_puts(int port, const char *s)
+{
+	while(*s)
+		uart_putc(port, *(s++));
+	return(0);
+}
+
+/*
+ * uart_putc
+ *
+ * Write a byte to the port.
+ */
+int
+uart_putc(int port, char c)
+{
+	/* spin until the byte can be sent */
+	while (-1 == uart_hw_putc(port, c))
+		task_yield();
+	return(0);
+}
+
+/*
+ * uart_debug_reader_task
+ *
+ * This helper task polls the configured serial port and
+ * feeds bytes read from it into the console input queue.
+ */
+static int
+uart_reader_task(void *arg)
+{
+	int		port = (int)arg;
+	u_int8_t	port_mask;
+	int		c;
+
+	/* work out what the enable mask is for this port */
+	switch (port) {
+#if defined(DEBUG_SERIAL_PORT)
+	case DEBUG_SERIAL_PORT:
+		port_mask = kPowerNVRAMiBootDebugIAPSerial;
+		break;
+#if defined(DEBUG_SERIAL_PORT2)
+	case DEBUG_SERIAL_PORT2:
+		port_mask = kPowerNVRAMiBootDebugAltSerial;
+		break;
+#endif	
+#endif
+	default:
+		ASSERT(false);
+		return(0);
+	}
+
+	/* loop reading bytes */
+	for(;;) {
+		/* ask the port for a byte, waiting if required */
+		c = uart_getc(port, true);
+
+		/* if our port is enabled, feed it to the input queue */
+		if (DebugUartReady & port_mask)
+			debug_pushchar(c);
+
+		/* yield to avoid hogging */
+		task_yield();
+	}
+	return(0);
+}
+