diff options
Diffstat (limited to 'nuttx/arch/arm/src/lpc2378/lpc23xx_lowputc.S')
| -rwxr-xr-x | nuttx/arch/arm/src/lpc2378/lpc23xx_lowputc.S | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/nuttx/arch/arm/src/lpc2378/lpc23xx_lowputc.S b/nuttx/arch/arm/src/lpc2378/lpc23xx_lowputc.S new file mode 100755 index 000000000..1d88b77fb --- /dev/null +++ b/nuttx/arch/arm/src/lpc2378/lpc23xx_lowputc.S @@ -0,0 +1,262 @@ +/************************************************************************** + * 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 <spudmonkey@racsa.co.cr> + * + * 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 <nuttx/config.h> +#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 |