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nuttx/arch/arm/src/lpc214x/lpc214x_lowputc.S
patacongo 36df84c843 Email address change in nuttx/ 
git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5145 42af7a65-404d-4744-a932-0658087f49c3
2012-09-13 18:32:24 +00:00

210 lines
7.1 KiB
ArmAsm
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/**************************************************************************
* arch/arm/src/lpc214x/lpc214X_lowputc.S
*
* Copyright (C) 2007, 2008 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* 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 "chip.h"
#include "up_arch.h"
#include "up_internal.h"
#include "lpc214x_pinsel.h"
#include "lpc214x_uart.h"
/**************************************************************************
* Private Definitions
**************************************************************************/
#if defined(CONFIG_UART0_SERIAL_CONSOLE)
# define LPC214X_UART_BASE LPC214X_UART0_BASE
# define LPC214X_UART_PINSEL LPC214X_UART0_PINSEL
# define LPC214X_UART_PINMASK LPC214X_UART0_PINMASK
# define LPC214X_UART_BAUD CONFIG_UART0_BAUD
# define LPC214X_UART_BITS CONFIG_UART0_BITS
# define LPC214X_UART_PARITY CONFIG_UART0_PARITY
# define LPC214X_UART_2STOP CONFIG_UART0_2STOP
#elif defined(CONFIG_UART1_SERIAL_CONSOLE)
# define LPC214X_UART_BASE LPC214X_UART1_BASE
# define LPC214X_UART_PINSEL LPC214X_UART1_PINSEL
# define LPC214X_UART_PINMASK LPC214X_UART1_PINMASK
# define LPC214X_UART_BAUD CONFIG_UART1_BAUD
# define LPC214X_UART_BITS CONFIG_UART1_BITS
# define LPC214X_UART_PARITY CONFIG_UART1_PARITY
# define LPC214X_UART_2STOP CONFIG_UART1_2STOP
#else
# error "No CONFIG_UARTn_SERIAL_CONSOLE Setting"
#endif
#if LPC214X_UART_BITS == 5
# define LPC214X_LCR_CHAR LPC214X_LCR_CHAR_5
#elif LPC214X_UART_BITS == 6
# define LPC214X_LCR_CHAR LPC214X_LCR_CHAR_6
#elif LPC214X_UART_BITS == 7
# define LPC214X_LCR_CHAR LPC214X_LCR_CHAR_7
#elif LPC214X_UART_BITS == 8
# define LPC214X_LCR_CHAR LPC214X_LCR_CHAR_8
#else
# error "No CONFIG_UARTn_BITS Setting"
#endif
#if LPC214X_UART_PARITY == 0
# define LPC214X_LCR_PAR LPC214X_LCR_PAR_NONE
#elif LPC214X_UART_PARITY == 1
# define LPC214X_LCR_PAR LPC214X_LCR_PAR_ODD
#elif LPC214X_UART_PARITY == 2
# define LPC214X_LCR_PAR LPC214X_LCR_PAR_EVEN
#elif LPC214X_UART_PARITY == 3
# define LPC214X_LCR_PAR LPC214X_LCR_PAR_MARK
#elif LPC214X_UART_PARITY == 4
# define LPC214X_LCR_PAR LPC214X_LCR_PAR_SPACE
#else
# error "No CONFIG_UARTn_PARITY Setting"
#endif
#if LPC214X_UART_2STOP != 0
# define LPC214X_LCR_STOP LPC214X_LCR_STOP_2
#else
# define LPC214X_LCR_STOP LPC214X_LCR_STOP_1
#endif
#define LPC214X_LCR_VALUE (LPC214X_LCR_CHAR | LPC214X_LCR_PAR | LPC214X_LCR_STOP)
#define LPC214X_FCR_VALUE (LPC214X_FCR_FIFO_TRIG8 | LPC214X_FCR_TX_FIFO_RESET |\
LPC214X_FCR_RX_FIFO_RESET | LPC214X_FCR_FIFO_ENABLE)
/**************************************************************************
* 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 can 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, =LPC214X_UART_BASE
strb r0, [r1, #LPC214X_UART_THR_OFFSET]
/* Wait for the byte to be transferred */
1: ldr r0, [r1, #LPC214X_UART_LSR_OFFSET]
ands r0, #LPC214X_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, =LPC214X_PINSEL0
ldr r1, [r0]
ldr r2, =~LPC214X_UART_PINMASK
and r1, r2
ldr r2, =LPC214X_UART_PINSEL
orr r1, r2
str r1, [r0]
/* Configure parity, data bits, stop bits and set DLAB=1 */
ldr r0, =LPC214X_UART_BASE
mov r1, #(LPC214X_LCR_VALUE | LPC214X_LCR_DLAB_ENABLE)
strb r1, [r0, #LPC214X_UART_LCR_OFFSET]
/* Set the BAUD divisor */
mov r1, #(UART_BAUD(LPC214X_UART_BAUD) >> 8)
strb r1, [r0, #LPC214X_UART_DLM_OFFSET]
mov r1, #(UART_BAUD(LPC214X_UART_BAUD) & 0xff)
strb r1, [r0, #LPC214X_UART_DLL_OFFSET]
/* Clear DLAB */
mov r1, #LPC214X_LCR_VALUE
strb r1, [r0, #LPC214X_UART_LCR_OFFSET]
/* Configure the FIFOs */
mov r1, #LPC214X_FCR_VALUE
strb r1, [r0, #LPC214X_UART_FCR_OFFSET]
/* And return */
mov pc, lr
.size up_lowsetup, . - up_lowsetup
.end
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