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nuttx/arch/arm/src/kl/kl_lowputc.c
Gregory Nutt 9c63736c98 Standard some naming if code sectino comments
2016-02-21 18:06:09 -06:00

336 lines
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/****************************************************************************
* arch/arm/src/kl/kl_lowputc.c
*
* Copyright (C) 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 "kl_config.h"
#include "kl_lowputc.h"
#include "kl_gpio.h"
#include "chip/kl_uart.h"
#include "chip/kl_sim.h"
#include "chip/kl_port.h"
#include "chip/kl_uart.h"
#include "chip/kl_pinmux.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Select UART parameters for the selected console */
#if defined(CONFIG_UART0_SERIAL_CONSOLE)
# define CONSOLE_BASE KL_UART0_BASE
# define CONSOLE_FREQ BOARD_CORECLK_FREQ
# define CONSOLE_BAUD CONFIG_UART0_BAUD
# define CONSOLE_BITS CONFIG_UART0_BITS
# define CONSOLE_PARITY CONFIG_UART0_PARITY
#elif defined(CONFIG_UART1_SERIAL_CONSOLE)
# define CONSOLE_BASE KL_UART1_BASE
# define CONSOLE_FREQ BOARD_BUSCLK_FREQ
# define CONSOLE_BAUD CONFIG_UART1_BAUD
# define CONSOLE_BITS CONFIG_UART1_BITS
# define CONSOLE_PARITY CONFIG_UART1_PARITY
#elif defined(CONFIG_UART2_SERIAL_CONSOLE)
# define CONSOLE_BASE KL_UART2_BASE
# define CONSOLE_FREQ BOARD_BUSCLK_FREQ
# define CONSOLE_BAUD CONFIG_UART2_BAUD
# define CONSOLE_BITS CONFIG_UART2_BITS
# define CONSOLE_PARITY CONFIG_UART2_PARITY
#endif
#define OVER_SAMPLE 16
/****************************************************************************
* Private Types
****************************************************************************/
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: up_lowputc
*
* Description:
* Output one byte on the serial console
*
****************************************************************************/
void kl_lowputc(uint32_t ch)
{
#if defined HAVE_UART_DEVICE && defined HAVE_SERIAL_CONSOLE
/* Wait until the transmit data register is "empty" (TDRE). This state
* depends on the TX watermark setting and may not mean that the transmit
* buffer is truly empty. It just means that we can now add another
* characterto the transmit buffer without exceeding the watermark.
*
* NOTE: UART0 has an 8-byte deep FIFO; the other UARTs have no FIFOs
* (1-deep). There appears to be no way to know when the FIFO is not
* full (other than reading the FIFO length and comparing the FIFO count).
* Hence, the FIFOs are not used in this implementation and, as a result
* TDRE indeed mean that the single output buffer is available.
*
* Performance on UART0 could be improved by enabling the FIFO and by
* redesigning all of the FIFO status logic.
*/
while ((getreg8(CONSOLE_BASE+KL_UART_S1_OFFSET) & UART_S1_TDRE) == 0);
/* Then write the character to the UART data register */
putreg8((uint8_t)ch, CONSOLE_BASE+KL_UART_D_OFFSET);
#endif
}
/****************************************************************************
* Name: kl_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.
*
****************************************************************************/
void kl_lowsetup(void)
{
uint32_t regval;
uint8_t regval8;
#if 0
regval = getreg32(KL_SIM_SOPT2);
regval |= SIM_SOPT2_PLLFLLSEL | SIM_SOPT2_UART0SRC_MCGCLK ;
putreg32(regval, KL_SIM_SOPT2);
#endif
regval = getreg32(KL_SIM_SCGC4);
#ifdef CONFIG_KL_UART0
regval |= SIM_SCGC4_UART0;
#endif
#ifdef CONFIG_KL_UART1
regval |= SIM_SCGC4_UART1;
#endif
#ifdef CONFIG_KL_UART2
regval |= SIM_SCGC4_UART2;
#endif
putreg32(regval, KL_SIM_SCGC4);
regval = getreg32(KL_SIM_SOPT2);
regval &= ~(SIM_SOPT2_UART0SRC_MASK);
putreg32(regval, KL_SIM_SOPT2);
regval = getreg32(KL_SIM_SOPT2);
regval |= SIM_SOPT2_UART0SRC_MCGCLK;
putreg32(regval, KL_SIM_SOPT2);
putreg32((PORT_PCR_MUX_ALT2), KL_PORTA_PCR1);
putreg32((PORT_PCR_MUX_ALT2), KL_PORTA_PCR2);
/* Disable UART before changing registers */
putreg8(0, KL_UART0_C2);
putreg8(0, KL_UART0_C1);
putreg8(0, KL_UART0_C3);
putreg8(0, KL_UART0_S2);
/* Set the baud rate divisor */
uint16_t divisor = (CONSOLE_FREQ / OVER_SAMPLE) / CONSOLE_BAUD;
regval8 = OVER_SAMPLE - 1;
putreg8(regval8, KL_UART0_C4);
regval8 = (divisor >> 8) & UART_BDH_SBR_MASK;
putreg8(regval8, KL_UART0_BDH);
regval8 = (divisor & UART_BDL_SBR_MASK);
putreg8(regval8, KL_UART0_BDL);
/* Enable UART before changing registers */
regval8 = getreg8(KL_UART0_C2);
regval8 |= (UART_C2_RE | UART_C2_TE);
putreg8(regval8, KL_UART0_C2);
/* Configure the console (only) now. Other UARTs will be configured
* when the serial driver is opened.
*/
#if defined(HAVE_SERIAL_CONSOLE) && !defined(CONFIG_SUPPRESS_UART_CONFIG)
kl_uartconfigure(CONSOLE_BASE, CONSOLE_BAUD, CONSOLE_FREQ,
CONSOLE_PARITY, CONSOLE_BITS);
#endif
}
/****************************************************************************
* Name: kl_uartreset
*
* Description:
* Reset a UART.
*
****************************************************************************/
#ifdef HAVE_UART_DEVICE
void kl_uartreset(uintptr_t uart_base)
{
uint8_t regval;
/* Just disable the transmitter and receiver */
regval = getreg8(uart_base + KL_UART_C2_OFFSET);
regval &= ~(UART_C2_RE | UART_C2_TE);
putreg8(regval, uart_base + KL_UART_C2_OFFSET);
}
#endif
/****************************************************************************
* Name: kl_uartconfigure
*
* Description:
* Configure a UART as a RS-232 UART.
*
****************************************************************************/
#ifdef HAVE_UART_DEVICE
void kl_uartconfigure(uintptr_t uart_base, uint32_t baud, uint32_t clock,
unsigned int parity, unsigned int nbits)
{
uint32_t sbr;
uint32_t tmp;
uint8_t regval;
/* Disable the transmitter and receiver throughout the reconfiguration */
regval = getreg8(uart_base+KL_UART_C2_OFFSET);
regval &= ~(UART_C2_RE | UART_C2_TE);
putreg8(regval, uart_base+KL_UART_C2_OFFSET);
/* Configure number of bits, stop bits and parity */
regval = 0;
/* Check for odd parity */
if (parity == 1)
{
regval |= (UART_C1_PE | UART_C1_PT); /* Enable + odd parity type */
}
/* Check for even parity */
else if (parity == 2)
{
regval |= UART_C1_PE; /* Enable (even parity default) */
}
/* The only other option is no parity */
else
{
DEBUGASSERT(parity == 0);
}
/* Check for 9-bit operation */
if (nbits == 9)
{
regval |= UART_C1_M;
}
/* The only other option is 8-bit operation */
else
{
DEBUGASSERT(nbits == 8);
}
putreg8(regval, uart_base + KL_UART_C1_OFFSET);
/* Calculate baud settings (truncating) */
sbr = clock / (baud << 4);
DEBUGASSERT(sbr < 0x2000);
/* Save the new baud divisor, retaining other bits in the UARTx_BDH
* register.
*/
regval = getreg8(uart_base + KL_UART_BDH_OFFSET) & UART_BDH_SBR_MASK;
tmp = sbr >> 8;
regval |= (((uint8_t)tmp) << UART_BDH_SBR_SHIFT) & UART_BDH_SBR_MASK;
putreg8(regval, uart_base + KL_UART_BDH_OFFSET);
regval = sbr & 0xff;
putreg8(regval, uart_base + KL_UART_BDL_OFFSET);
/* Now we can (re-)enable the transmitter and receiver */
regval = getreg8(uart_base + KL_UART_C2_OFFSET);
regval |= (UART_C2_RE | UART_C2_TE);
putreg8(regval, uart_base + KL_UART_C2_OFFSET);
}
#endif
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