rt-thread/bsp/at91sam9g45/drivers/usart.c

/*
 * File      : usart.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author       Notes
 * 2011-01-13     weety       first version
 * 2013-07-21     weety       using serial component
 */

#include <rtthread.h>
#include <rthw.h>
#include <at91sam9g45.h>
#include <rtdevice.h>


struct at91_uart {
	AT91S_USART *port;
	int irq;
};


/**
 * This function will handle serial port interrupt
 */
void rt_at91_usart_handler(int vector, void *param)
{
	int status;
	struct at91_uart *uart;
	rt_device_t dev = (rt_device_t)param;
	uart = (struct at91_uart *)dev->user_data;
	status = uart->port->US_CSR;
	if (!(status & uart->port->US_IMR)) /* check actived and enabled interrupt */
	{
		return;
	}
	rt_interrupt_enter();
	rt_hw_serial_isr((struct rt_serial_device *)dev, RT_SERIAL_EVENT_RX_IND);
	rt_interrupt_leave();
}

/**
 * UART device in RT-Thread
 */
static rt_err_t at91_usart_configure(struct rt_serial_device *serial,
                                struct serial_configure *cfg)
{
	int div;
	int mode = 0;
	struct at91_uart *uart;

	RT_ASSERT(serial != RT_NULL);
    RT_ASSERT(cfg != RT_NULL);
	uart = (struct at91_uart *)serial->parent.user_data;

	uart->port->US_CR = AT91C_US_RSTTX | AT91C_US_RSTRX |
	       AT91C_US_RXDIS | AT91C_US_TXDIS;
	mode |= AT91C_US_USMODE_NORMAL | AT91C_US_CLKS_CLOCK |
	       AT91C_US_CHMODE_NORMAL;
	switch (cfg->data_bits)
	{
	case DATA_BITS_8:
		mode |= AT91C_US_CHRL_8_BITS;
		break;
	case DATA_BITS_7:
		mode |= AT91C_US_CHRL_7_BITS;
		break;
	case DATA_BITS_6:
		mode |= AT91C_US_CHRL_6_BITS;
		break;
	case DATA_BITS_5:
		mode |= AT91C_US_CHRL_5_BITS;
		break;
	default:
		mode |= AT91C_US_CHRL_8_BITS;
		break;
	}

	switch (cfg->stop_bits)
	{
	case STOP_BITS_2:
		mode |= AT91C_US_NBSTOP_2_BIT;
		break;
	case STOP_BITS_1:
	default:
		mode |= AT91C_US_NBSTOP_1_BIT;
		break;
	}

	switch (cfg->parity)
	{
	case PARITY_ODD:
		mode |= AT91C_US_PAR_ODD;
		break;
	case PARITY_EVEN:
		mode |= AT91C_US_PAR_EVEN;
		break;
	case PARITY_NONE:
	default:
		mode |= AT91C_US_PAR_NONE;
		break;
	}

	uart->port->US_MR = mode;
    /* Assume OVER is cleared and fractional baudrate generator is disabled */
	div = (clk_get_rate(clk_get("mck")) / 16 + cfg->baud_rate/2) / cfg->baud_rate;
	uart->port->US_BRGR = div;
	uart->port->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;
	uart->port->US_IER = AT91C_US_RXRDY;

    return RT_EOK;
}

static rt_err_t at91_usart_control(struct rt_serial_device *serial,
                              int cmd, void *arg)
{
    struct at91_uart* uart;

    RT_ASSERT(serial != RT_NULL);
    uart = (struct at91_uart *)serial->parent.user_data;

    switch (cmd)
    {
    case RT_DEVICE_CTRL_CLR_INT:
        /* disable rx irq */
		rt_hw_interrupt_mask(uart->irq);
        break;
    case RT_DEVICE_CTRL_SET_INT:
        /* enable rx irq */
		rt_hw_interrupt_umask(uart->irq);
        break;
    }

    return RT_EOK;
}

static int at91_usart_putc(struct rt_serial_device *serial, char c)
{
    //rt_uint32_t level;
	struct at91_uart *uart = serial->parent.user_data;

    while (!(uart->port->US_CSR & AT91C_US_TXRDY));
	uart->port->US_THR = c;

    return 1;
}

static int at91_usart_getc(struct rt_serial_device *serial)
{
    int result;
	struct at91_uart *uart = serial->parent.user_data;

    if (uart->port->US_CSR & AT91C_US_RXRDY)
	{
		result = uart->port->US_RHR & 0xff;
	}
	else
	{
		result = -1;
	}

    return result;
}

static const struct rt_uart_ops at91_usart_ops =
{
    at91_usart_configure,
    at91_usart_control,
    at91_usart_putc,
    at91_usart_getc,
};

#if defined(RT_USING_DBGU)
static struct rt_serial_device serial_dbgu;
struct at91_uart dbgu = {
	(AT91PS_USART)AT91C_BASE_DBGU,
	AT91C_ID_SYS
};

#endif

#if defined(RT_USING_UART0)
static struct rt_serial_device serial0;
struct at91_uart uart0 = {
	AT91C_BASE_US0,
	AT91C_ID_US0
};
#endif

#if defined(RT_USING_UART1)
static struct rt_serial_device serial1;
struct at91_uart uart1 = {
	AT91C_BASE_US1,
	AT91C_ID_US1
};
#endif

#if defined(RT_USING_UART2)
static struct rt_serial_device serial2;
struct at91_uart uart2 = {
	AT91C_BASE_US2,
	AT91C_ID_US2
};
#endif

#if defined(RT_USING_UART3)
static struct rt_serial_device serial3;
struct at91_uart uart3 = {
	AT91C_BASE_US3,
	AT91C_ID_US3
};
#endif


void at91_usart_gpio_init(void)
{
#ifdef RT_USING_DBGU
#define DRXD	12		// DBGU  rx as Peripheral A on PB12
#define DTXD	13		// DBGU  tx as Peripheral A on PB13
	AT91C_BASE_PIOB->PIO_IDR,   (1<<DRXD)|(1<<DTXD);   // Disables the Input Change Interrupt on the I/O line
	AT91C_BASE_PIOB->PIO_PPUDR, (1<<DRXD)|(1<<DTXD);   // Disables the pull up resistor on the I/O line
	AT91C_BASE_PIOB->PIO_ASR,   (1<<DRXD)|(1<<DTXD);   // Assigns the I/O line to the Peripheral A function
	AT91C_BASE_PIOB->PIO_PDR,   (1<<DRXD)|(1<<DTXD);   // enables peripheral control of the pin
	AT91C_BASE_PMC->PMC_PCER,    1 << AT91C_ID_SYS;
#endif

#ifdef RT_USING_UART0
#define RXD0    18		// UART0 rx as Peripheral A on PB18
#define TXD0    19		// UART0 tx as Peripheral A on PB19
	AT91C_BASE_PMC->PMC_PCER,    1 << AT91C_ID_US0;
	AT91C_BASE_PIOB->PIO_IDR,   (1<<RXD0)|(1<<TXD0);
	AT91C_BASE_PIOB->PIO_PPUER, (1<<RXD0);
	AT91C_BASE_PIOB->PIO_PPUDR, (1<<TXD0);
	AT91C_BASE_PIOB->PIO_ASR,   (1<<RXD0)|(1<<TXD0);
	AT91C_BASE_PIOB->PIO_PDR,   (1<<RXD0)|(1<<TXD0);
#endif

#ifdef RT_USING_UART1
#define TXD1     4		// UART1 tx as Peripheral A on PB4
#define RXD1     5		// UART1 rx as Peripheral A on PB5
	AT91C_BASE_PMC->PMC_PCER,    1 << AT91C_ID_US1;
	AT91C_BASE_PIOB->PIO_IDR,   (1<<RXD1)|(1<<TXD1);
	AT91C_BASE_PIOB->PIO_PPUER, (1<<RXD1);
	AT91C_BASE_PIOB->PIO_PPUDR, (1<<TXD1);
	AT91C_BASE_PIOB->PIO_ASR,   (1<<RXD1)|(1<<TXD1);
	AT91C_BASE_PIOB->PIO_PDR,   (1<<RXD1)|(1<<TXD1);
#endif

#ifdef RT_USING_UART2
#define TXD2     6		// UART2 tx as Peripheral A on PB6
#define RXD2     7		// UART2 rx as Peripheral A on PB7
	AT91C_BASE_PMC->PMC_PCER,    1 << AT91C_ID_US2;
	AT91C_BASE_PIOB->PIO_IDR,   (1<<RXD2)|(1<<TXD2);
	AT91C_BASE_PIOB->PIO_PPUER, (1<<RXD2);
	AT91C_BASE_PIOB->PIO_PPUDR, (1<<TXD2);
	AT91C_BASE_PIOB->PIO_ASR,   (1<<RXD2)|(1<<TXD2);
	AT91C_BASE_PIOB->PIO_PDR,   (1<<RXD2)|(1<<TXD2);
#endif

#ifdef RT_USING_UART3
#define TXD3     8		// UART3 tx as Peripheral A on PB8
#define RXD3     9		// UART3 rx as Peripheral A on PB9
	AT91C_BASE_PMC->PMC_PCER,    1<<AT91C_ID_US3;
	AT91C_BASE_PIOB->PIO_IDR,   (1<<RXD3)|(1<<TXD3);
	AT91C_BASE_PIOB->PIO_PPUER, (1<<RXD3);
	AT91C_BASE_PIOB->PIO_PPUDR, (1<<TXD3);
	AT91C_BASE_PIOB->PIO_ASR,   (1<<RXD3)|(1<<TXD3);
	AT91C_BASE_PIOB->PIO_PDR,   (1<<RXD3)|(1<<TXD3);
#endif
}

/**
 * This function will handle init uart
 */
int rt_hw_uart_init(void)
{
	at91_usart_gpio_init();

#if defined(RT_USING_DBGU)
	serial_dbgu.ops = &at91_usart_ops;
	serial_dbgu.config.baud_rate = BAUD_RATE_115200;
    serial_dbgu.config.bit_order = BIT_ORDER_LSB;
    serial_dbgu.config.data_bits = DATA_BITS_8;
    serial_dbgu.config.parity = PARITY_NONE;
    serial_dbgu.config.stop_bits = STOP_BITS_1;
    serial_dbgu.config.invert = NRZ_NORMAL;
	serial_dbgu.config.bufsz = RT_SERIAL_RB_BUFSZ;

    /* register vcom device */
    rt_hw_serial_register(&serial_dbgu, "dbgu",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          &dbgu);
#endif

#if defined(RT_USING_UART0)
	serial0.ops = &at91_usart_ops;
	serial0.config.baud_rate = BAUD_RATE_115200;
    serial0.config.bit_order = BIT_ORDER_LSB;
    serial0.config.data_bits = DATA_BITS_8;
    serial0.config.parity = PARITY_NONE;
    serial0.config.stop_bits = STOP_BITS_1;
    serial0.config.invert = NRZ_NORMAL;
	serial0.config.bufsz = RT_SERIAL_RB_BUFSZ;

    /* register vcom device */
    rt_hw_serial_register(&serial0, "uart0",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX | RT_DEVICE_FLAG_STREAM,
                          &uart0);
	rt_hw_interrupt_install(uart0.irq, rt_at91_usart_handler,
							(void *)&(serial0.parent), "UART0");
	rt_hw_interrupt_umask(uart0.irq);
#endif

#if defined(RT_USING_UART1)
	serial1.ops = &at91_usart_ops;
	serial1.config.baud_rate = BAUD_RATE_115200;
    serial1.config.bit_order = BIT_ORDER_LSB;
    serial1.config.data_bits = DATA_BITS_8;
    serial1.config.parity = PARITY_NONE;
    serial1.config.stop_bits = STOP_BITS_1;
    serial1.config.invert = NRZ_NORMAL;
	serial1.config.bufsz = RT_SERIAL_RB_BUFSZ;

    /* register vcom device */
    rt_hw_serial_register(&serial1, "uart1",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          &uart1);
	rt_hw_interrupt_install(uart1.irq, rt_at91_usart_handler,
							(void *)&(serial1.parent), "UART1");
	rt_hw_interrupt_umask(uart1.irq);
#endif

#if defined(RT_USING_UART2)
	serial2.ops = &at91_usart_ops;
	serial2.config.baud_rate = BAUD_RATE_115200;
    serial2.config.bit_order = BIT_ORDER_LSB;
    serial2.config.data_bits = DATA_BITS_8;
    serial2.config.parity = PARITY_NONE;
    serial2.config.stop_bits = STOP_BITS_1;
    serial2.config.invert = NRZ_NORMAL;
	serial2.config.bufsz = RT_SERIAL_RB_BUFSZ;

    /* register vcom device */
    rt_hw_serial_register(&serial2, "uart2",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          &uart2);
	rt_hw_interrupt_install(uart2.irq, rt_at91_usart_handler,
							(void *)&(serial2.parent), "UART2");
	rt_hw_interrupt_umask(uart2.irq);
#endif

#if defined(RT_USING_UART3)
	serial3.ops = &at91_usart_ops;
	serial3.config.baud_rate = BAUD_RATE_115200;
    serial3.config.bit_order = BIT_ORDER_LSB;
    serial3.config.data_bits = DATA_BITS_8;
    serial3.config.parity = PARITY_NONE;
    serial3.config.stop_bits = STOP_BITS_1;
    serial3.config.invert = NRZ_NORMAL;
	serial3.config.bufsz = RT_SERIAL_RB_BUFSZ;

    /* register vcom device */
    rt_hw_serial_register(&serial3, "uart3",
                          RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX,
                          &uart3);
	rt_hw_interrupt_install(uart3.irq, rt_at91_usart_handler,
							(void *)&(serial3.parent), "UART3");
	rt_hw_interrupt_umask(uart3.irq);
#endif

	return 0;
}

INIT_BOARD_EXPORT(rt_hw_uart_init);

#ifdef RT_USING_DBGU
void rt_dbgu_isr(void)
{
	rt_at91_usart_handler(dbgu.irq, &(serial_dbgu.parent));
}
#endif