/************************************************************************** * arch/arm/src/lpc17xx/lpc17_lowputc.c * * Copyright (C) 2010-2012 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 #include #include #include "up_internal.h" #include "up_arch.h" #include "lpc17_internal.h" #include "lpc17_syscon.h" #include "lpc17_uart.h" #include "lpc17_serial.h" /************************************************************************** * Private Definitions **************************************************************************/ /* Select UART parameters for the selected console */ #if defined(CONFIG_UART0_SERIAL_CONSOLE) # define CONSOLE_BASE LPC17_UART0_BASE # define CONSOLE_BAUD CONFIG_UART0_BAUD # define CONSOLE_BITS CONFIG_UART0_BITS # define CONSOLE_PARITY CONFIG_UART0_PARITY # define CONSOLE_2STOP CONFIG_UART0_2STOP #elif defined(CONFIG_UART1_SERIAL_CONSOLE) # define CONSOLE_BASE LPC17_UART1_BASE # define CONSOLE_BAUD CONFIG_UART1_BAUD # define CONSOLE_BITS CONFIG_UART1_BITS # define CONSOLE_PARITY CONFIG_UART1_PARITY # define CONSOLE_2STOP CONFIG_UART1_2STOP #elif defined(CONFIG_UART2_SERIAL_CONSOLE) # define CONSOLE_BASE LPC17_UART2_BASE # define CONSOLE_BAUD CONFIG_UART2_BAUD # define CONSOLE_BITS CONFIG_UART2_BITS # define CONSOLE_PARITY CONFIG_UART2_PARITY # define CONSOLE_2STOP CONFIG_UART2_2STOP #elif defined(CONFIG_UART3_SERIAL_CONSOLE) # define CONSOLE_BASE LPC17_UART3_BASE # define CONSOLE_BAUD CONFIG_UART3_BAUD # define CONSOLE_BITS CONFIG_UART3_BITS # define CONSOLE_PARITY CONFIG_UART3_PARITY # define CONSOLE_2STOP CONFIG_UART3_2STOP #elif defined(HAVE_CONSOLE) # error "No CONFIG_UARTn_SERIAL_CONSOLE Setting" #endif /* Get word length setting for the console */ #if CONSOLE_BITS == 5 # define CONSOLE_LCR_WLS UART_LCR_WLS_5BIT #elif CONSOLE_BITS == 6 # define CONSOLE_LCR_WLS UART_LCR_WLS_6BIT #elif CONSOLE_BITS == 7 # define CONSOLE_LCR_WLS UART_LCR_WLS_7BIT #elif CONSOLE_BITS == 8 # define CONSOLE_LCR_WLS UART_LCR_WLS_8BIT #elif defined(HAVE_CONSOLE) # error "Invalid CONFIG_UARTn_BITS setting for console " #endif /* Get parity setting for the console */ #if CONSOLE_PARITY == 0 # define CONSOLE_LCR_PAR 0 #elif CONSOLE_PARITY == 1 # define CONSOLE_LCR_PAR (UART_LCR_PE|UART_LCR_PS_ODD) #elif CONSOLE_PARITY == 2 # define CONSOLE_LCR_PAR (UART_LCR_PE|UART_LCR_PS_EVEN) #elif CONSOLE_PARITY == 3 # define CONSOLE_LCR_PAR (UART_LCR_PE|UART_LCR_PS_STICK1) #elif CONSOLE_PARITY == 4 # define CONSOLE_LCR_PAR (UART_LCR_PE|UART_LCR_PS_STICK0) #elif defined(HAVE_CONSOLE) # error "Invalid CONFIG_UARTn_PARITY setting for CONSOLE" #endif /* Get stop-bit setting for the console and UART0-3 */ #if CONSOLE_2STOP != 0 # define CONSOLE_LCR_STOP UART_LCR_STOP #else # define CONSOLE_LCR_STOP 0 #endif /* LCR and FCR values for the console */ #define CONSOLE_LCR_VALUE (CONSOLE_LCR_WLS | CONSOLE_LCR_PAR | CONSOLE_LCR_STOP) #define CONSOLE_FCR_VALUE (UART_FCR_RXTRIGGER_8 | UART_FCR_TXRST |\ UART_FCR_RXRST | UART_FCR_FIFOEN) /* Select a CCLK divider to produce the UART PCLK. The strategy is to select the * smallest divisor that results in an solution within range of the 16-bit * DLM and DLL divisor: * * BAUD = PCLK / (16 * DL), or * DL = PCLK / BAUD / 16 * * Where: * * PCLK = CCLK / divisor * * Ignoring the fractional divider for now. (If you want to extend this driver * to support the fractional divider, see lpc43xx_uart.c. The LPC43xx uses * the same peripheral and that logic could easily leveraged here). * * Check divisor == 1. This works if the upper limit is met: * * DL < 0xffff, or * PCLK / BAUD / 16 < 0xffff, or * CCLK / BAUD / 16 < 0xffff, or * CCLK < BAUD * 0xffff * 16 * BAUD > CCLK / 0xffff / 16 * * And the lower limit is met (we can't allow DL to get very close to one). * * DL >= MinDL * CCLK / BAUD / 16 >= MinDL, or * BAUD <= CCLK / 16 / MinDL */ #if CONSOLE_BAUD < (LPC17_CCLK / 16 / UART_MINDL) # define CONSOLE_CCLKDIV SYSCON_PCLKSEL_CCLK # define CONSOLE_NUMERATOR (LPC17_CCLK) /* Check divisor == 2. This works if: * * 2 * CCLK / BAUD / 16 < 0xffff, or * BAUD > CCLK / 0xffff / 8 * * And * * 2 * CCLK / BAUD / 16 >= MinDL, or * BAUD <= CCLK / 8 / MinDL */ #elif CONSOLE_BAUD < (LPC17_CCLK / 8 / UART_MINDL) # define CONSOLE_CCLKDIV SYSCON_PCLKSEL_CCLK2 # define CONSOLE_NUMERATOR (LPC17_CCLK / 2) /* Check divisor == 4. This works if: * * 4 * CCLK / BAUD / 16 < 0xffff, or * BAUD > CCLK / 0xffff / 4 * * And * * 4 * CCLK / BAUD / 16 >= MinDL, or * BAUD <= CCLK / 4 / MinDL */ #elif CONSOLE_BAUD < (LPC17_CCLK / 4 / UART_MINDL) # define CONSOLE_CCLKDIV SYSCON_PCLKSEL_CCLK4 # define CONSOLE_NUMERATOR (LPC17_CCLK / 4) /* Check divisor == 8. This works if: * * 8 * CCLK / BAUD / 16 < 0xffff, or * BAUD > CCLK / 0xffff / 2 * * And * * 8 * CCLK / BAUD / 16 >= MinDL, or * BAUD <= CCLK / 2 / MinDL */ #else /* if CONSOLE_BAUD < (LPC17_CCLK / 2 / UART_MINDL) */ # define CONSOLE_CCLKDIV SYSCON_PCLKSEL_CCLK8 # define CONSOLE_NUMERATOR (LPC17_CCLK / 8) #endif /* Then this is the value to use for the DLM and DLL registers */ #define CONSOLE_DL (CONSOLE_NUMERATOR / (CONSOLE_BAUD << 4)) /************************************************************************** * Private Types **************************************************************************/ /************************************************************************** * Private Function Prototypes **************************************************************************/ /************************************************************************** * Global Variables **************************************************************************/ /************************************************************************** * Private Variables **************************************************************************/ /************************************************************************** * Private Functions **************************************************************************/ /************************************************************************** * Public Functions **************************************************************************/ /************************************************************************** * Name: up_lowputc * * Description: * Output one byte on the serial console * **************************************************************************/ void up_lowputc(char ch) { #if defined HAVE_UART && defined HAVE_CONSOLE /* Wait for the transmitter to be available */ while ((getreg32(CONSOLE_BASE+LPC17_UART_LSR_OFFSET) & UART_LSR_THRE) == 0); /* Send the character */ putreg32((uint32_t)ch, CONSOLE_BASE+LPC17_UART_THR_OFFSET); #endif } /************************************************************************** * Name: lpc17_lowsetup * * Description: * This performs basic initialization of the UART used for the serial * console. Its purpose is to get the console output availabe as soon * as possible. * * The UART0/1/2/3 peripherals are configured using the following registers: * 1. Power: In the PCONP register, set bits PCUART0/1/2/3. * On reset, UART0 and UART 1 are enabled (PCUART0 = 1 and PCUART1 = 1) * and UART2/3 are disabled (PCUART1 = 0 and PCUART3 = 0). * 2. Peripheral clock: In the PCLKSEL0 register, select PCLK_UART0 and * PCLK_UART1; in the PCLKSEL1 register, select PCLK_UART2 and PCLK_UART3. * 3. Baud rate: In the LCR register, set bit DLAB = 1. This enables access * to registers DLL and DLM for setting the baud rate. Also, if needed, * set the fractional baud rate in the fractional divider * 4. UART FIFO: Use bit FIFO enable (bit 0) in FCR register to * enable FIFO. * 5. Pins: Select UART pins through the PINSEL registers and pin modes * through the PINMODE registers. UART receive pins should not have * pull-down resistors enabled. * 6. Interrupts: To enable UART interrupts set bit DLAB = 0 in the LCRF * register. This enables access to IER. Interrupts are enabled * in the NVIC using the appropriate Interrupt Set Enable register. * 7. DMA: UART transmit and receive functions can operate with the * GPDMA controller. * **************************************************************************/ void lpc17_lowsetup(void) { #ifdef HAVE_UART uint32_t regval; /* Step 1: Enable power for all console UART and disable power for * other UARTs */ regval = getreg32(LPC17_SYSCON_PCONP); regval &= ~(SYSCON_PCONP_PCUART0|SYSCON_PCONP_PCUART1| SYSCON_PCONP_PCUART2|SYSCON_PCONP_PCUART3); #if defined(CONFIG_UART0_SERIAL_CONSOLE) regval |= SYSCON_PCONP_PCUART0; #elif defined(CONFIG_UART1_SERIAL_CONSOLE) regval |= SYSCON_PCONP_PCUART1; #elif defined(CONFIG_UART2_SERIAL_CONSOLE) regval |= SYSCON_PCONP_PCUART2; #elif defined(CONFIG_UART3_SERIAL_CONSOLE) regval |= SYSCON_PCONP_PCUART3; #endif putreg32(regval, LPC17_SYSCON_PCONP); /* Step 2: Enable peripheral clocking for the console UART and disable * clocking for all other UARTs */ regval = getreg32(LPC17_SYSCON_PCLKSEL0); regval &= ~(SYSCON_PCLKSEL0_UART0_MASK|SYSCON_PCLKSEL0_UART1_MASK); #if defined(CONFIG_UART0_SERIAL_CONSOLE) regval |= (CONSOLE_CCLKDIV << SYSCON_PCLKSEL0_UART0_SHIFT); #elif defined(CONFIG_UART1_SERIAL_CONSOLE) regval |= (CONSOLE_CCLKDIV << SYSCON_PCLKSEL0_UART1_SHIFT); #endif putreg32(regval, LPC17_SYSCON_PCLKSEL0); regval = getreg32(LPC17_SYSCON_PCLKSEL1); regval &= ~(SYSCON_PCLKSEL1_UART2_MASK|SYSCON_PCLKSEL1_UART3_MASK); #if defined(CONFIG_UART2_SERIAL_CONSOLE) regval |= (CONSOLE_CCLKDIV << SYSCON_PCLKSEL1_UART2_SHIFT); #elif defined(CONFIG_UART3_SERIAL_CONSOLE) regval |= (CONSOLE_CCLKDIV << SYSCON_PCLKSEL1_UART3_SHIFT); #endif putreg32(regval, LPC17_SYSCON_PCLKSEL1); /* Configure UART pins for the selected CONSOLE */ #if defined(CONFIG_UART0_SERIAL_CONSOLE) lpc17_configgpio(GPIO_UART0_TXD); lpc17_configgpio(GPIO_UART0_RXD); #elif defined(CONFIG_UART1_SERIAL_CONSOLE) lpc17_configgpio(GPIO_UART1_TXD); lpc17_configgpio(GPIO_UART1_RXD); #ifdef CONFIG_UART1_FLOWCONTROL lpc17_configgpio(GPIO_UART1_CTS); lpc17_configgpio(GPIO_UART1_DCD); lpc17_configgpio(GPIO_UART1_DSR); lpc17_configgpio(GPIO_UART1_DTR); lpc17_configgpio(GPIO_UART1_RI); lpc17_configgpio(GPIO_UART1_RTS); #endif #elif defined(CONFIG_UART2_SERIAL_CONSOLE) lpc17_configgpio(GPIO_UART2_TXD); lpc17_configgpio(GPIO_UART2_RXD); #elif defined(CONFIG_UART3_SERIAL_CONSOLE) lpc17_configgpio(GPIO_UART3_TXD); lpc17_configgpio(GPIO_UART3_RXD); #endif /* Configure the console (only) */ #if defined(HAVE_CONSOLE) && !defined(CONFIG_SUPPRESS_UART_CONFIG) /* Clear fifos */ putreg32(UART_FCR_RXRST|UART_FCR_TXRST, CONSOLE_BASE+LPC17_UART_FCR_OFFSET); /* Set trigger */ putreg32(UART_FCR_FIFOEN|UART_FCR_RXTRIGGER_8, CONSOLE_BASE+LPC17_UART_FCR_OFFSET); /* Set up the LCR and set DLAB=1 */ putreg32(CONSOLE_LCR_VALUE|UART_LCR_DLAB, CONSOLE_BASE+LPC17_UART_LCR_OFFSET); /* Set the BAUD divisor */ putreg32(CONSOLE_DL >> 8, CONSOLE_BASE+LPC17_UART_DLM_OFFSET); putreg32(CONSOLE_DL & 0xff, CONSOLE_BASE+LPC17_UART_DLL_OFFSET); /* Clear DLAB */ putreg32(CONSOLE_LCR_VALUE, CONSOLE_BASE+LPC17_UART_LCR_OFFSET); /* Configure the FIFOs */ putreg32(UART_FCR_RXTRIGGER_8|UART_FCR_TXRST|UART_FCR_RXRST|UART_FCR_FIFOEN, CONSOLE_BASE+LPC17_UART_FCR_OFFSET); #endif #endif /* HAVE_UART */ }