/************************************************************************** * arch/arm/src/lpc2378/lpc23xx_lowputc.S * * Copyright (C) 2010 Rommel Marcelo. All rights reserved. * Author: Rommel Marcelo * * This file is part of the NuttX RTOS and based on the lpc2148 port: * * Copyright (C) 2010 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * **************************************************************************/ /************************************************************************** * Included Files **************************************************************************/ #include #include "up_internal.h" #include "up_arch.h" #include "lpc23xx_pinsel.h" #include "lpc23xx_scb.h" #include "lpc23xx_uart.h" /************************************************************************** * Private Definitions **************************************************************************/ @ //-- Pins @ PINSEL0 |= (0x01<<4) | //-- P0.2 TXD0 @ (0x01<<6); //-- P0.3 RXD0 @PCLKSEL0 |= (0x01 << 6); //-- bit 7:6 =01-> Clock div = 1 for UART0 #if defined(CONFIG_UART0_SERIAL_CONSOLE) # define UARTxBASE UART0_BASE_ADDR # define PINSELECT LPC23XX_PINSEL0 # define UARTxPCLKSEL 0xE01FC1A8 # define PCLKSEL_MASK U0_PCLKSEL_MASK # define UARTxPINSEL UART0_PINSEL # define UARTxPINMASK UART0_PINMASK # define UARTxBAUD CONFIG_UART0_BAUD # define UARTxBITS CONFIG_UART0_BITS # define UARTxPARITY CONFIG_UART0_PARITY # define UARTx2STOP CONFIG_UART0_2STOP #elif defined(CONFIG_UART1_SERIAL_CONSOLE) # define UARTxBASE UART1_BASE_ADDR /* # define PINSELECT LPC23XX_PINSEL1 only Uart0/Uart2 share same Pinsel */ # define UARTxPCLKSEL 0xE01FC1A8 # define PCLKSEL_MASK U1_PCLKSEL_MASK # define UARTxPINSEL UART1_PINSEL # define UARTxPINMASK UART1_PINMASK # define UARTxBAUD CONFIG_UART1_BAUD # define UARTxBITS CONFIG_UART1_BITS # define UARTxPARITY CONFIG_UART1_PARITY # define UARTx2STOP CONFIG_UART1_2STOP #elif defined(CONFIG_UART2_SERIAL_CONSOLE) # define UARTxBASE UART2_BASE_ADDR # define PINSELECT LPC23XX_PINSEL0 # define UARTxPCLKSEL 0xE01FC1AC # define PCLKSEL_MASK U2_PCLKSEL_MASK # define UARTxPINSEL UART2_PINSEL # define UARTxPINMASK UART2_PINMASK # define UARTxBAUD CONFIG_UART2_BAUD # define UARTxBITS CONFIG_UART2_BITS # define UARTxPARITY CONFIG_UART2_PARITY # define UARTx2STOP CONFIG_UART2_2STOP #elif defined(CONFIG_UART3_SERIAL_CONSOLE) # define PINSELECT LPC23XX_PINSEL0 # define UARTxBASE UART3_BASE_ADDR # define UARTxPCLKSEL 0xE01FC1AC # define PCLKSEL_MASK U2_PCLKSEL_MASK # define UARTxPINSEL UART3_PINSEL # define UARTxPINMASK UART3_PINMASK # define UARTxBAUD CONFIG_UART3_BAUD # define UARTxBITS CONFIG_UART3_BITS # define UARTxPARITY CONFIG_UART3_PARITY # define UARTx2STOP CONFIG_UART3_2STOP #else # error "No CONFIG_UARTn_SERIAL_CONSOLE Setting" #endif #if UARTxBITS == 5 # define LCR_CHAR LCR_CHAR_5 #elif UARTxBITS == 6 # define LCR_CHAR LCR_CHAR_6 #elif UARTxBITS == 7 # define LCR_CHAR LCR_CHAR_7 #elif UARTxBITS == 8 # define LCR_CHAR LCR_CHAR_8 #else # error "No CONFIG_UARTn_BITS Setting" #endif #if UARTxPARITY == 0 # define LCR_PAR LCR_PAR_NONE #elif UARTxPARITY == 1 # define LCR_PAR LCR_PAR_ODD #elif UARTxPARITY == 2 # define LCR_PAR LCR_PAR_EVEN #elif UARTxPARITY == 3 # define LCR_PAR LCR_PAR_MARK #elif UARTxPARITY == 4 # define LCR_PAR LCR_PAR_SPACE #else # error "No CONFIG_UARTn_PARITY Setting" #endif #if UARTx2STOP != 0 # define LCR_STOP LCR_STOP_2 #else # define LCR_STOP LCR_STOP_1 #endif #define LCR_VALUE (LCR_CHAR | LCR_PAR | LCR_STOP) #define FCR_VALUE (FCR_FIFO_TRIG8 | FCR_TX_FIFO_RESET | \ FCR_RX_FIFO_RESET | FCR_FIFO_ENABLE) @#define MULVAL (12 << 4) @#define DIVADDVAL 3 /************************************************************************** * Private Types **************************************************************************/ /************************************************************************** * Private Function Prototypes **************************************************************************/ /************************************************************************** * Global Variables **************************************************************************/ /************************************************************************** * Private Variables **************************************************************************/ /************************************************************************** * Private Functions **************************************************************************/ /************************************************************************** * Public Functions **************************************************************************/ /************************************************************************** * Name: up_lowputc **************************************************************************/ /* This assembly language version has the advantage that it does not * require a C stack and uses only r0-r1. Hence it can be used during * early boot phases. */ .text .global up_lowputc .type up_lowputc, function up_lowputc: /* On entry, r0 holds the character to be printed */ ldr r1, =UARTxBASE strb r0, [r1, #UART_THR_OFFSET] /* Wait for the byte to be transferred */ 1: ldr r0, [r1, #UART_LSR_OFFSET] ands r0, #LSR_TEMT /* Transmitter empty */ beq 1b /* And return */ mov pc, lr .size up_lowputc, . - up_lowputc /* This performs basic initialization of the UART. This can be called very * early in initialization because it does not depend on having a stack. It * modifies r0-r2 and r14. */ .text .globl up_lowsetup .type up_lowsetup, function up_lowsetup: /* Configure PINSEL0 */ ldr r0, =PINSELECT /* TODO: generalize this for different uart pins */ ldr r1, [r0] ldr r2, =(~UARTxPINMASK) and r1, r2 ldr r2, =(UARTxPINSEL) orr r1, r2 str r1, [r0] /* Power Up Uart0 */ ldr r0, =UARTxPCLKSEL /* PCLKSEL0 address */ ldr r1, [r0] ldr r2, =(~PCLKSEL_MASK) and r1, r2 ldr r2, =(U0_PCLKSEL) orr r1, r2 str r1, [r0] /* Configure parity, data bits, stop bits and set DLAB=1 */ ldr r0, =UARTxBASE mov r1, #(LCR_VALUE | LCR_DLAB_ENABLE) strb r1, [r0, #UART_LCR_OFFSET] /* Set the BAUD divisor */ mov r1, #((MULVAL << 4) | DIVADDVAL) strb r1, [r0, #UART_FDR_OFFSET] mov r1, #DLMVAL strb r1, [r0, #UART_DLM_OFFSET] mov r1, #DLLVAL strb r1, [r0, #UART_DLL_OFFSET] /* Clear DLAB and Set format 8N1 */ mov r1, #LCR_VALUE strb r1, [r0, #UART_LCR_OFFSET] /* Configure the FIFOs */ mov r1, #FCR_VALUE strb r1, [r0, #UART_FCR_OFFSET] mov r1, #LCR_VALUE strb r1, [r0, #UART_LCR_OFFSET] /* And return */ mov pc, lr .size up_lowsetup, . - up_lowsetup .end