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rt-thread/bsp/cv1800b/drivers/drv_uart.c

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/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2023/06/25 flyingcys first version
*/
#include <rthw.h>
#include <rtthread.h>
#include <rtdevice.h>
#include "board.h"
#include "drv_uart.h"
#define DBG_TAG "DRV.UART"
#define DBG_LVL DBG_WARNING
#include <rtdbg.h>
/*
* The Synopsys DesignWare 8250 has an extra feature whereby it detects if the
* LCR is written whilst busy. If it is, then a busy detect interrupt is
* raised, the LCR needs to be rewritten and the uart status register read.
*/
#define UART_RX 0 /* In: Receive buffer */
#define UART_TX 0 /* Out: Transmit buffer */
#define UART_DLL 0 /* Out: Divisor Latch Low */
#define UART_DLM 1 /* Out: Divisor Latch High */
#define UART_IER 1 /* Out: Interrupt Enable Register */
#define UART_IER_RDI 0x01 /* Enable receiver data interrupt */
#define UART_SSR 0x22 /* In: Software Reset Register */
#define UART_USR 0x1f /* UART Status Register */
#define UART_LCR 3 /* Out: Line Control Register */
#define UART_LCR_DLAB 0x80 /* Divisor latch access bit */
#define UART_LCR_SPAR 0x20 /* Stick parity (?) */
#define UART_LCR_PARITY 0x8 /* Parity Enable */
#define UART_LCR_STOP 0x4 /* Stop bits: 0=1 bit, 1=2 bits */
#define UART_LCR_WLEN8 0x3 /* Wordlength: 8 bits */
#define UART_MCR 4 /* Out: Modem Control Register */
#define UART_MCR_RTS 0x02 /* RTS complement */
#define UART_LSR 5 /* In: Line Status Register */
#define UART_LSR_BI 0x10 /* Break interrupt indicator */
#define UART_LSR_DR 0x01 /* Receiver data ready */
#define UART_IIR 2 /* In: Interrupt ID Register */
#define UART_IIR_NO_INT 0x01 /* No interrupts pending */
#define UART_IIR_BUSY 0x07 /* DesignWare APB Busy Detect */
#define UART_IIR_RX_TIMEOUT 0x0c /* OMAP RX Timeout interrupt */
#define UART_FCR 2 /* Out: FIFO Control Register */
#define UART_FCR_EN_FIFO 0x01 /* Enable the FIFO */
#define UART_FCR_CLEAR_RCVR 0x02 /* Clear the RCVR FIFO */
#define UART_FCR_CLEAR_XMIT 0x04 /* Clear the XMIT FIFO */
struct hw_uart_device
{
rt_ubase_t hw_base;
rt_uint32_t irqno;
};
#define BSP_DEFINE_UART_DEVICE(no) \
static struct hw_uart_device _uart##no##_device = \
{ \
UART##no##_BASE, \
UART##no##_IRQ \
}; \
static struct rt_serial_device _serial##no;
#ifdef RT_USING_UART0
BSP_DEFINE_UART_DEVICE(0);
#endif
#ifdef RT_USING_UART1
BSP_DEFINE_UART_DEVICE(1);
#endif
#ifdef RT_USING_UART2
BSP_DEFINE_UART_DEVICE(2);
#endif
#ifdef RT_USING_UART3
BSP_DEFINE_UART_DEVICE(3);
#endif
rt_inline rt_uint32_t dw8250_read32(rt_ubase_t addr, rt_ubase_t offset)
{
return *((volatile rt_uint32_t *)(addr + (offset << UART_REG_SHIFT)));
}
rt_inline void dw8250_write32(rt_ubase_t addr, rt_ubase_t offset, rt_uint32_t value)
{
*((volatile rt_uint32_t *)(addr + (offset << UART_REG_SHIFT))) = value;
if (offset == UART_LCR)
{
int tries = 1000;
/* Make sure LCR write wasn't ignored */
while (tries--)
{
unsigned int lcr = dw8250_read32(addr, UART_LCR);
if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
{
return;
}
dw8250_write32(addr, UART_FCR, UART_FCR_EN_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
dw8250_read32(addr, UART_RX);
*((volatile rt_uint32_t *)(addr + (offset << UART_REG_SHIFT))) = value;
}
}
}
static rt_err_t dw8250_uart_configure(struct rt_serial_device *serial, struct serial_configure *cfg)
{
rt_base_t base, rate;
struct hw_uart_device *uart;
RT_ASSERT(serial != RT_NULL);
uart = (struct hw_uart_device *)serial->parent.user_data;
base = uart->hw_base;
/* Resset UART */
dw8250_write32(base, UART_SSR, 1);
dw8250_write32(base, UART_SSR, 0);
dw8250_write32(base, UART_IER, !UART_IER_RDI);
dw8250_write32(base, UART_FCR, UART_FCR_EN_FIFO | UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT);
/* Disable flow ctrl */
dw8250_write32(base, UART_MCR, 0);
/* Clear RTS */
dw8250_write32(base, UART_MCR, dw8250_read32(base, UART_MCR) | UART_MCR_RTS);
rate = UART_INPUT_CLK / 16 / serial->config.baud_rate;
/* Enable access DLL & DLH */
dw8250_write32(base, UART_LCR, dw8250_read32(base, UART_LCR) | UART_LCR_DLAB);
dw8250_write32(base, UART_DLL, (rate & 0xff));
dw8250_write32(base, UART_DLM, (rate & 0xff00) >> 8);
/* Clear DLAB bit */
dw8250_write32(base, UART_LCR, dw8250_read32(base, UART_LCR) & (~UART_LCR_DLAB));
dw8250_write32(base, UART_LCR, (dw8250_read32(base, UART_LCR) & (~UART_LCR_WLEN8)) | UART_LCR_WLEN8);
dw8250_write32(base, UART_LCR, dw8250_read32(base, UART_LCR) & (~UART_LCR_STOP));
dw8250_write32(base, UART_LCR, dw8250_read32(base, UART_LCR) & (~UART_LCR_PARITY));
dw8250_write32(base, UART_IER, UART_IER_RDI);
return RT_EOK;
}
static rt_err_t dw8250_uart_control(struct rt_serial_device *serial, int cmd, void *arg)
{
struct hw_uart_device *uart;
RT_ASSERT(serial != RT_NULL);
uart = (struct hw_uart_device *)serial->parent.user_data;
switch (cmd)
{
case RT_DEVICE_CTRL_CLR_INT:
/* Disable rx irq */
dw8250_write32(uart->hw_base, UART_IER, !UART_IER_RDI);
rt_hw_interrupt_mask(uart->irqno);
break;
case RT_DEVICE_CTRL_SET_INT:
/* Enable rx irq */
dw8250_write32(uart->hw_base, UART_IER, UART_IER_RDI);
rt_hw_interrupt_umask(uart->irqno);
break;
}
return RT_EOK;
}
static int dw8250_uart_putc(struct rt_serial_device *serial, char c)
{
rt_base_t base;
struct hw_uart_device *uart;
RT_ASSERT(serial != RT_NULL);
uart = (struct hw_uart_device *)serial->parent.user_data;
base = uart->hw_base;
while ((dw8250_read32(base, UART_USR) & 0x2) == 0)
{
}
dw8250_write32(base, UART_TX, c);
return 1;
}
static int dw8250_uart_getc(struct rt_serial_device *serial)
{
int ch = -1;
rt_base_t base;
struct hw_uart_device *uart;
RT_ASSERT(serial != RT_NULL);
uart = (struct hw_uart_device *)serial->parent.user_data;
base = uart->hw_base;
if ((dw8250_read32(base, UART_LSR) & 0x1))
{
ch = dw8250_read32(base, UART_RX) & 0xff;
}
return ch;
}
static const struct rt_uart_ops _uart_ops =
{
dw8250_uart_configure,
dw8250_uart_control,
dw8250_uart_putc,
dw8250_uart_getc,
};
static void rt_hw_uart_isr(int irqno, void *param)
{
unsigned int iir, status;
struct rt_serial_device *serial = (struct rt_serial_device *)param;
struct hw_uart_device *uart = (struct hw_uart_device *)serial->parent.user_data;
iir = dw8250_read32(uart->hw_base, UART_IIR);
/* If don't do this in non-DMA mode then the "RX TIMEOUT" interrupt will fire forever. */
if ((iir & 0x3f) == UART_IIR_RX_TIMEOUT)
{
status = dw8250_read32(uart->hw_base, UART_LSR);
if (!(status & (UART_LSR_DR | UART_LSR_BI)))
{
dw8250_read32(uart->hw_base, UART_RX);
}
}
if (!(iir & UART_IIR_NO_INT))
{
rt_hw_serial_isr(serial, RT_SERIAL_EVENT_RX_IND);
}
if ((iir & UART_IIR_BUSY) == UART_IIR_BUSY)
{
/* Clear the USR */
dw8250_read32(uart->hw_base, UART_USR);
return;
}
}
int rt_hw_uart_init(void)
{
struct hw_uart_device* uart;
struct serial_configure config = RT_SERIAL_CONFIG_DEFAULT;
config.baud_rate = 115200;
#define BSP_INSTALL_UART_DEVICE(no) \
uart = &_uart##no##_device; \
_serial##no.ops = &_uart_ops; \
_serial##no.config = config; \
rt_hw_serial_register(&_serial##no, "uart" #no, RT_DEVICE_FLAG_RDWR | RT_DEVICE_FLAG_INT_RX, uart); \
rt_hw_interrupt_install(uart->irqno, rt_hw_uart_isr, &_serial##no, "uart" #no);
#ifdef RT_USING_UART0
BSP_INSTALL_UART_DEVICE(0);
#endif
#ifdef RT_USING_UART1
BSP_INSTALL_UART_DEVICE(1);
#endif
#ifdef RT_USING_UART2
BSP_INSTALL_UART_DEVICE(2);
#endif
#ifdef RT_USING_UART3
BSP_INSTALL_UART_DEVICE(3);
#endif
return 0;
}
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