/************************************************************************** * arch/arm/src/lpc43xx/lpc43_uart.c * * Copyright (C) 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 "chip.h" #include "lpc43_config.h" #include "lpc43_pinconfig.h" #include "lpc43_rgu.h" #include "lpc43_cgu.h" #include "lpc43_uart.h" /************************************************************************** * Private Definitions **************************************************************************/ /* Select UART parameters for the selected console */ #if defined(CONFIG_USART0_SERIAL_CONSOLE) # define CONSOLE_BASE LPC43_USART0_BASE # define CONSOLE_BASEFREQ BOARD_USART0_BASEFREQ # define CONSOLE_BAUD CONFIG_USART0_BAUD # define CONSOLE_BITS CONFIG_USART0_BITS # define CONSOLE_PARITY CONFIG_USART0_PARITY # define CONSOLE_2STOP CONFIG_USART0_2STOP #elif defined(CONFIG_UART1_SERIAL_CONSOLE) # define CONSOLE_BASE LPC43_UART1_BASE # define CONSOLE_BASEFREQ BOARD_UART1_BASEFREQ # 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_USART2_SERIAL_CONSOLE) # define CONSOLE_BASE LPC43_USART2_BASE # define CONSOLE_BASEFREQ BOARD_USART2_BASEFREQ # define CONSOLE_BAUD CONFIG_USART2_BAUD # define CONSOLE_BITS CONFIG_USART2_BITS # define CONSOLE_PARITY CONFIG_USART2_PARITY # define CONSOLE_2STOP CONFIG_USART2_2STOP #elif defined(CONFIG_USART3_SERIAL_CONSOLE) # define CONSOLE_BASE LPC43_USART3_BASE # define CONSOLE_BASEFREQ BOARD_USART3_BASEFREQ # define CONSOLE_BAUD CONFIG_USART3_BAUD # define CONSOLE_BITS CONFIG_USART3_BITS # define CONSOLE_PARITY CONFIG_USART3_PARITY # define CONSOLE_2STOP CONFIG_USART3_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 USART0/2/3, UART1 */ #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) /************************************************************************** * 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+LPC43_UART_LSR_OFFSET) & UART_LSR_THRE) == 0); /* Send the character */ putreg32((uint32_t)ch, CONSOLE_BASE+LPC43_UART_THR_OFFSET); #endif } /************************************************************************** * Name: lpc43_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 USART0/2/3 and UART1 peripherals are configured using the following registers: * 1. Power: In the PCONP register, set bits PCUSART0/1/2/3. * On reset, USART0 and UART 1 are enabled (PCUSART0 = 1 and PCUART1 = 1) * and USART2/3 are disabled (PCUART1 = 0 and PCUSART3 = 0). * 2. Peripheral clock: In the PCLKSEL0 register, select PCLK_USART0 and * PCLK_UART1; in the PCLKSEL1 register, select PCLK_USART2 and PCLK_USART3. * 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 lpc43_lowsetup(void) { #ifdef HAVE_UART /* Enable clocking and for all console UART and disable power for * other UARTs */ #if defined(CONFIG_USART0_SERIAL_CONSOLE) lpc43_usart0_setup(); #elif defined(CONFIG_UART1_SERIAL_CONSOLE) lpc43_uart1_setup(); #elif defined(CONFIG_USART2_SERIAL_CONSOLE) lpc43_usart2_setup(); #elif defined(CONFIG_USART3_SERIAL_CONSOLE) lpc43_usart3_setup(); #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+LPC43_UART_FCR_OFFSET); /* Set trigger */ putreg32(UART_FCR_FIFOEN|UART_FCR_RXTRIGGER_8, CONSOLE_BASE+LPC43_UART_FCR_OFFSET); /* Set up the LCR */ putreg32(CONSOLE_LCR_VALUE, CONSOLE_BASE+LPC43_UART_LCR_OFFSET); /* Set the BAUD divisor */ lpc43_setbaud(CONSOLE_BASE, CONSOLE_BASEFREQ, CONSOLE_BAUD); /* Configure the FIFOs */ putreg32(UART_FCR_RXTRIGGER_8|UART_FCR_TXRST|UART_FCR_RXRST|UART_FCR_FIFOEN, CONSOLE_BASE+LPC43_UART_FCR_OFFSET); #endif #endif /* HAVE_UART */ } /**************************************************************************** * Name: lpc43_u[s]art0/1/2/3_reset * * Description: * Reset a UART. These functions are used by the serial driver when a * UART is closed. * ****************************************************************************/ #ifdef CONFIG_LPC43_USART0 void lpc43_usart0_reset(void) { putreg32(RGU_CTRL1_USART0_RST, LPC43_RGU_CTRL1); } #endif #ifdef CONFIG_LPC43_UART1 void lpc43_uart1_reset(void) { putreg32(RGU_CTRL1_UART1_RST, LPC43_RGU_CTRL1); } #endif #ifdef CONFIG_LPC43_USART2 void lpc43_usart2_reset(void) { putreg32(RGU_CTRL1_USART2_RST, LPC43_RGU_CTRL1); } #endif #ifdef CONFIG_LPC43_USART3 void lpc43_usart3_reset(void) { putreg32(RGU_CTRL1_USART3_RST, LPC43_RGU_CTRL1); } #endif /**************************************************************************** * Name: lpc43_usart0_setup, lpc43_uart1_setup, lpc43_usart2_setup, and * lpc43_usart3_setup * * Description: * Configure the U[S]ART. This involves: * * 1. Connecting the input clock to the U[S]ART as specified in the * board.h file, * 2. Configuring the U[S]ART pins * * USART0/2/3 and UART1 clocking and power control: * * ----------------------------------- -------------- -------------- * BASE CLOCK BRANCH CLOCK * ----------------------------------- -------------- -------------- * USART0 clock to register interface BASE_M4_CLK CLK_M4_USART0 * USART0 peripheral clock (PCLK) BASE_UART0_CLK CLK_APB0_UART0 * UART1 clock to register interface BASE_M4_CLK CLK_M4_UART1 * UART1 peripheral clock (PCLK) BASE_UART1_CLK CLK_APB0_UART1 * USART2 clock to register interface BASE_M4_CLK CLK_M4_USART2 * USART2 peripheral clock (PCLK) BASE_UART2_CLK CLK_APB2_UART2 * USART3 clock to register interface BASE_M4_CLK CLK_M4_USART3 * USART3 peripheral clock (PCLK) BASE_UART3_CLK CLK_APB2_UART3 * ----------------------------------- -------------- -------------- * ****************************************************************************/ #ifdef CONFIG_LPC43_USART0 void lpc43_usart0_setup(void) { uint32_t regval; irqstate_t flags; /* Connect USART0 into the clock source specified in board.h */ flags = irqsave(); regval = getreg32(LPC43_BASE_USART0_CLK); regval &= ~BASE_USART0_CLK_CLKSEL_MASK; regval |= (BOARD_USART0_CLKSRC | BASE_USART0_CLK_AUTOBLOCK); putreg32(regval, LPC43_BASE_USART0_CLK); /* Configure I/O pins. NOTE that multiple pin configuration options must * be disambiguated by defining the pin configuration in the board.h * header file. */ lpc43_pin_config(PINCONF_U0_TXD); lpc43_pin_config(PINCONF_U0_RXD); /* If USART RS-485 mode is selected, then configure the DIR pin as well. * NOTE, again, that multiple pin configuration options must be * disambiguated by defining the pin configuration in the board.h header * file. */ #ifdef CONFIG_USART0_RS485MODE lpc43_pin_config(PINCONF_U0_DIR); #endif irqrestore(flags); }; #endif #ifdef CONFIG_LPC43_UART1 void lpc43_uart1_setup(void) { uint32_t regval; irqstate_t flags; /* Connect UART1 into the clock source specified in board.h */ flags = irqsave(); regval = getreg32(LPC43_BASE_UART1_CLK); regval &= ~BASE_UART1_CLK_CLKSEL_MASK; regval |= (BOARD_UART1_CLKSRC | BASE_UART1_CLK_AUTOBLOCK); putreg32(regval, LPC43_BASE_UART1_CLK); /* Configure I/O pins. NOTE that multiple pin configuration options must * be disambiguated by defining the pin configuration in the board.h * header file. */ lpc43_pin_config(PINCONF_U1_TXD); lpc43_pin_config(PINCONF_U1_RXD); #ifdef CONFIG_UART1_FLOWCONTROL lpc43_pin_config(PINCONF_U1_CTS); lpc43_pin_config(PINCONF_U1_DCD); lpc43_pin_config(PINCONF_U1_DSR); lpc43_pin_config(PINCONF_U1_DTR); lpc43_pin_config(PINCONF_U1_RTS); #ifdef CONFIG_UART1_RINGINDICATOR lpc43_pin_config(PINCONF_U1_RI); #endif #endif irqrestore(flags); }; #endif #ifdef CONFIG_LPC43_USART2 void lpc43_usart2_setup(void) { uint32_t regval; irqstate_t flags; /* Connect USART2 the clock source specified in board.h */ flags = irqsave(); regval = getreg32(LPC43_BASE_USART2_CLK); regval &= ~BASE_USART2_CLK_CLKSEL_MASK; regval |= (BOARD_USART2_CLKSRC | BASE_USART2_CLK_AUTOBLOCK); putreg32(regval, LPC43_BASE_USART2_CLK); /* Configure I/O pins. NOTE that multiple pin configuration options must * be disambiguated by defining the pin configuration in the board.h * header file. */ lpc43_pin_config(PINCONF_U2_TXD); lpc43_pin_config(PINCONF_U2_RXD); /* If USART RS-485 mode is selected, then configure the DIR pin as well. * NOTE, again, that multiple pin configuration options must be * disambiguated by defining the pin configuration in the board.h header * file. */ #ifdef CONFIG_USART2_RS485MODE lpc43_pin_config(PINCONF_U2_DIR); #endif irqrestore(flags); }; #endif #ifdef CONFIG_LPC43_USART3 void lpc43_usart3_setup(void) { uint32_t regval; irqstate_t flags; /* Connect USART3 into the clock source specified in board.h */ flags = irqsave(); regval = getreg32(LPC43_BASE_USART3_CLK); regval &= ~BASE_USART3_CLK_CLKSEL_MASK; regval |= (BOARD_USART3_CLKSRC | BASE_USART3_CLK_AUTOBLOCK); putreg32(regval, LPC43_BASE_USART3_CLK); /* Configure I/O pins. NOTE that multiple pin configuration options must * be disambiguated by defining the pin configuration in the board.h * header file. */ lpc43_pin_config(PINCONF_U3_TXD); lpc43_pin_config(PINCONF_U3_RXD); /* If USART RS-485 mode is selected, then configure the DIR pin as well. * NOTE, again, that multiple pin configuration options must be * disambiguated by defining the pin configuration in the board.h header * file. */ #ifdef CONFIG_USART3_RS485MODE lpc43_pin_config(PINCONF_U3_DIR); #endif irqrestore(flags); }; #endif /**************************************************************************** * Name: lpc43_setbaud * * Description: * Configure the U[S]ART divisors to accomplish the desired BAUD given the * U[S]ART base frequency. * * This computationally intensive algorithm is based on the same logic * used in the NXP sample code. * ****************************************************************************/ void lpc43_setbaud(uintptr_t uartbase, uint32_t basefreq, uint32_t baud) { uint32_t lcr; /* Line control register value */ uint32_t dl; /* Best DLM/DLL full value */ uint32_t mul; /* Best FDR MULVALL value */ uint32_t divadd; /* Best FDR DIVADDVAL value */ uint32_t best; /* Error value associated with best {dl, mul, divadd} */ uint32_t cdl; /* Candidate DLM/DLL full value */ uint32_t cmul; /* Candidate FDR MULVALL value */ uint32_t cdivadd; /* Candidate FDR DIVADDVAL value */ uint32_t errval; /* Error value associated with the candidate */ /* The U[S]ART buad is given by: * * Fbaud = Fbase * mul / (mul + divadd) / (16 * dl) * dl = Fbase * mul / (mul + divadd) / Fbaud / 16 * = Fbase * mul / ((mul + divadd) * Fbaud * 16) * = ((Fbase * mul) >> 4) / ((mul + divadd) * Fbaud) * * Where the value of MULVAL and DIVADDVAL comply with: * * 0 < mul < 16 * 0 <= divadd < mul */ best = UINT32_MAX; divadd = 0; mul = 0; dl = 0; /* Try each mulitplier value in the valid range */ for (cmul = 1 ; cmul < 16; cmul++) { /* Try each divider value in the valid range */ for (cdivadd = 0 ; cdivadd < cmul ; cdivadd++) { /* Candidate: * dl = ((Fbase * mul) >> 4) / ((mul + cdivadd) * Fbaud) * (dl << 32) = (Fbase << 28) * cmul / ((mul + cdivadd) * Fbaud) */ uint64_t dl64 = ((uint64_t)basefreq << 28) * cmul / ((cmul + cdivadd) * baud); /* The lower 32-bits of this value is the error */ errval = (uint32_t)(dl64 & 0x00000000ffffffffull); /* The upper 32-bits is the candidate DL value */ cdl = (uint32_t)(dl64 >> 32); /* Round up */ if (errval > (1 << 31)) { errval = -errval; cdl++; } /* Check if the resulting candidate DL value is within range */ if (cdl < 1 || cdl > 65536) { /* No... try a different divadd value */ continue; } /* Is this the best combination that we have seen so far? */ if (errval < best) { /* Yes.. then the candidate is out best guess so far */ best = errval; dl = cdl; divadd = cdivadd; mul = cmul; /* If the new best guess is exact (within our precision), then * we are finished. */ if (best == 0) { break; } } } } DEBUGASSERT(dl > 0); /* Enter DLAB=1 */ lcr = getreg32(uartbase + LPC43_UART_LCR_OFFSET); putreg32(lcr | UART_LCR_DLAB, uartbase + LPC43_UART_LCR_OFFSET); /* Save then divider values */ putreg32(dl >> 8, uartbase + LPC43_UART_DLM_OFFSET); putreg32(dl & 0xff, uartbase + LPC43_UART_DLL_OFFSET); /* Clear DLAB */ putreg32(lcr & ~UART_LCR_DLAB, uartbase + LPC43_UART_LCR_OFFSET); /* Then save the fractional divider values */ putreg32((mul << UART_FDR_MULVAL_SHIFT) | (divadd << UART_FDR_DIVADDVAL_SHIFT), uartbase + LPC43_UART_FDR_OFFSET); }