/**************************************************************************
* arch/arm/src/lpc17xx/lpc17_lowputc.c
*
* Copyright (C) 2010-2013 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 <stdint.h>
#include <arch/irq.h>
#include <arch/board/board.h>
#include "up_internal.h"
#include "up_arch.h"
#include "chip/lpc17_syscon.h"
#include "chip/lpc17_uart.h"
#include "lpc17_gpio.h"
#include "lpc17_lowputc.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 for the LPC176x the PCLK is determined by the UART-specific divisor in
* PCLKSEL0 or PCLKSEL1:
*
* PCLK = CCLK / divisor
*
* And for the LPC178x, the PCLK is determined by the global divisor setting in
* the PLKSEL register.
*
* 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).
*/
#ifdef LPC178x
/* Use the global PCLK frequency */
# define CONSOLE_NUMERATOR BOARD_PCLK_FREQUENCY
#else
/* Calculate and optimal PCLKSEL0/1 divisor.
* First, 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
#endif /* LPC178x */
/* 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
*/
#ifdef LPC176x
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);
#endif
/* 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 */
}
