drv_uart.c

/*
 * File      : drv_uart.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2009-2014 RT-Thread Develop Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2013-05-18     Bernard      The first version for LPC40xx
 * 2014-12-16     RT_learning  The first version for LPC5410x
 * 2017-08-01     XiaoYang     The first version for LPC546xx
 */


#include <rthw.h>
#include <rtthread.h>
#include <rtdevice.h>

#include "fsl_usart.h"
#include "fsl_common.h"
#include "fsl_iocon.h"



struct lpc_uart
{
    USART_Type *UART;
    IRQn_Type UART_IRQn;
};

static rt_err_t lpc_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
{
    struct lpc_uart *uart;
    usart_config_t u0_config;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct lpc_uart *)serial->parent.user_data;

    /*
     * config.baudRate_Bps = 115200U;
     * config.parityMode = kUSART_ParityDisabled;
     * config.stopBitCount = kUSART_OneStopBit;
     * config.loopback = false;
     * config.enableTx = false;
     * config.enableRx = false;
     */
    USART_GetDefaultConfig(&u0_config);
    u0_config.baudRate_Bps = cfg->baud_rate;
    u0_config.enableTx = true;
    u0_config.enableRx = true;

    USART_Init(uart->UART, &u0_config, CLOCK_GetFreq(kCLOCK_Flexcomm0));

    return RT_EOK;
}

static rt_err_t lpc_control(struct rt_serial_device *serial, int cmd, void *arg)
{
    struct lpc_uart *uart;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct lpc_uart *)serial->parent.user_data;

    switch (cmd)
    {
    case RT_DEVICE_CTRL_CLR_INT:
        /* disable rx irq */
        USART_DisableInterrupts(uart->UART, kUSART_RxLevelInterruptEnable);
        break;
    case RT_DEVICE_CTRL_SET_INT:
        /* enable rx irq */
        USART_EnableInterrupts(uart->UART, kUSART_RxLevelInterruptEnable);
        break;
    }

    return RT_EOK;
}

static int lpc_putc(struct rt_serial_device *serial, char c)
{
    struct lpc_uart *uart;

    uart = (struct lpc_uart *)serial->parent.user_data;

    while (!(kUSART_TxFifoNotFullFlag & USART_GetStatusFlags(uart->UART)));

    USART_WriteByte(uart->UART, c);

    return 1;
}

static int lpc_getc(struct rt_serial_device *serial)
{
    struct lpc_uart *uart;

    uart = (struct lpc_uart *)serial->parent.user_data;
    if (kUSART_RxFifoNotEmptyFlag & USART_GetStatusFlags(uart->UART))
    {
        return USART_ReadByte(uart->UART);
    }
    else
        return -1;
}

static const struct rt_uart_ops lpc_uart_ops =
{
    lpc_configure,
    lpc_control,
    lpc_putc,
    lpc_getc,
};


#define IOCON_PIO_DIGITAL_EN        0x0100u   /*!< Enables digital function */
#define IOCON_PIO_FUNC1               0x01u   /*!< Selects pin function 1 */
#define IOCON_PIO_INPFILT_OFF       0x0200u   /*!< Input filter disabled */
#define IOCON_PIO_INV_DI              0x00u   /*!< Input function is not inverted */
#define IOCON_PIO_MODE_INACT          0x00u   /*!< No addition pin function */
#define IOCON_PIO_OPENDRAIN_DI        0x00u   /*!< Open drain is disabled */
#define IOCON_PIO_SLEW_STANDARD       0x00u   /*!< Standard mode, output slew rate control is enabled */
#define PIN29_IDX                       29u   /*!< Pin number for pin 29 in a port 0 */
#define PIN30_IDX                       30u   /*!< Pin number for pin 30 in a port 0 */
#define PORT0_IDX                        0u   /*!< Port index */

/* UART0 device driver structure */
struct lpc_uart uart0 =
{
    USART0,
    FLEXCOMM0_IRQn,
};
struct rt_serial_device serial0;

void FLEXCOMM0_IRQHandler(void)
{
    /* enter interrupt */
    rt_interrupt_enter();

    rt_hw_serial_isr(&serial0, RT_SERIAL_EVENT_RX_IND);

    /* leave interrupt */
    rt_interrupt_leave();
}

void rt_hw_uart_init(void)
{
    struct lpc_uart *uart;
    struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;

#ifdef RT_USING_UART0
    
    uart = &uart0;

    serial0.ops    = &lpc_uart_ops;
    serial0.config = config;
    serial0.parent.user_data = uart;

    /* attach 12 MHz clock to FLEXCOMM0 (debug console) */
    CLOCK_AttachClk(kFRO12M_to_FLEXCOMM0);
    /* Enables the clock for the IOCON block. 0 = Disable; 1 = Enable.: 0x01u */
//    CLOCK_EnableClock(kCLOCK_Iocon);
    {
        const uint32_t port0_pin29_config = (
                                                IOCON_PIO_FUNC1 |                                        /* Pin is configured as FC0_RXD_SDA_MOSI */
                                                IOCON_PIO_MODE_INACT |                                   /* No addition pin function */
                                                IOCON_PIO_INV_DI |                                       /* Input function is not inverted */
                                                IOCON_PIO_DIGITAL_EN |                                   /* Enables digital function */
                                                IOCON_PIO_INPFILT_OFF |                                  /* Input filter disabled */
                                                IOCON_PIO_SLEW_STANDARD |                                /* Standard mode, output slew rate control is enabled */
                                                IOCON_PIO_OPENDRAIN_DI                                   /* Open drain is disabled */
                                            );
        IOCON_PinMuxSet(IOCON, PORT0_IDX, PIN29_IDX, port0_pin29_config); /* PORT0 PIN29 (coords: B13) is configured as FC0_RXD_SDA_MOSI */
        const uint32_t port0_pin30_config = (
                                                IOCON_PIO_FUNC1 |                                        /* Pin is configured as FC0_TXD_SCL_MISO */
                                                IOCON_PIO_MODE_INACT |                                   /* No addition pin function */
                                                IOCON_PIO_INV_DI |                                       /* Input function is not inverted */
                                                IOCON_PIO_DIGITAL_EN |                                   /* Enables digital function */
                                                IOCON_PIO_INPFILT_OFF |                                  /* Input filter disabled */
                                                IOCON_PIO_SLEW_STANDARD |                                /* Standard mode, output slew rate control is enabled */
                                                IOCON_PIO_OPENDRAIN_DI                                   /* Open drain is disabled */
                                            );
        IOCON_PinMuxSet(IOCON, PORT0_IDX, PIN30_IDX, port0_pin30_config); /* PORT0 PIN30 (coords: A2) is configured as FC0_TXD_SCL_MISO */
    }

    /* Enable RX interrupt. */
    USART_EnableInterrupts(uart->UART, kUSART_RxLevelInterruptEnable);
    EnableIRQ(uart->UART_IRQn);

    /* register UART0 device */
    rt_hw_serial_register(&serial0, "uart0",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_STREAM,
                          uart);
#endif    
}