/**************************************************************************
* 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 <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 "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
