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sdk:lib: rewrite uart 

Signed-off-by: liangkangnan <liangkangnan@163.com>
pull/4/head
liangkangnan 2021-08-07 14:30:29 +08:00
parent 58f180a92f
commit 72b982d133
3 changed files with 61 additions and 17 deletions
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63
sdk/bsp/include/uart.h
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@ -1,17 +1,60 @@
#ifndef _UART_H_
#define _UART_H_
#ifndef _UART_REG_DEFS_
#define _UART_REG_DEFS_
#define UART0_BASE (0x50000000)
#define UART0_CTRL (UART0_BASE + (0x00))
#define UART0_STATUS (UART0_BASE + (0x04))
#define UART0_BAUD (UART0_BASE + (0x08))
#define UART0_TXDATA (UART0_BASE + (0x0c))
#define UART0_RXDATA (UART0_BASE + (0x10))
#ifdef __cplusplus
extern "C" {
#endif
// Register width
#define UART_PARAM_REG_WIDTH 32
#define UART0_REG(addr) (*((volatile uint32_t *)addr))
#define UART0_BASE_ADDR (0x50000000)
#define UART0_REG(offset) (*((volatile uint32_t *)(UART0_BASE_ADDR + offset)))
// UART control register
#define UART_CTRL_REG_OFFSET 0x0
#define UART_CTRL_REG_RESVAL 0xd90000
#define UART_CTRL_TX_EN_BIT 0
#define UART_CTRL_RX_EN_BIT 1
#define UART_CTRL_TX_FIFO_EMPTY_INT_EN_BIT 2
#define UART_CTRL_RX_FIFO_NOT_EMPTY_INT_EN_BIT 3
#define UART_CTRL_TX_FIFO_RST_BIT 4
#define UART_CTRL_RX_FIFO_RST_BIT 5
#define UART_CTRL_BAUD_DIV_MASK 0xffff
#define UART_CTRL_BAUD_DIV_OFFSET 16
#define UART_CTRL_BAUD_DIV_FIELD \
((bitfield_field32_t) { .mask = UART_CTRL_BAUD_DIV_MASK, .index = UART_CTRL_BAUD_DIV_OFFSET })
// UART status register
#define UART_STATUS_REG_OFFSET 0x4
#define UART_STATUS_REG_RESVAL 0x3c
#define UART_STATUS_TXFULL_BIT 0
#define UART_STATUS_RXFULL_BIT 1
#define UART_STATUS_TXEMPTY_BIT 2
#define UART_STATUS_RXEMPTY_BIT 3
#define UART_STATUS_TXIDLE_BIT 4
#define UART_STATUS_RXIDLE_BIT 5
// UART TX data register
#define UART_TXDATA_REG_OFFSET 0x8
#define UART_TXDATA_REG_RESVAL 0x0
#define UART_TXDATA_TXDATA_MASK 0xff
#define UART_TXDATA_TXDATA_OFFSET 0
#define UART_TXDATA_TXDATA_FIELD \
((bitfield_field32_t) { .mask = UART_TXDATA_TXDATA_MASK, .index = UART_TXDATA_TXDATA_OFFSET })
// UART RX data register
#define UART_RXDATA_REG_OFFSET 0xc
#define UART_RXDATA_REG_RESVAL 0x0
#define UART_RXDATA_RXDATA_MASK 0xff
#define UART_RXDATA_RXDATA_OFFSET 0
#define UART_RXDATA_RXDATA_FIELD \
((bitfield_field32_t) { .mask = UART_RXDATA_RXDATA_MASK, .index = UART_RXDATA_RXDATA_OFFSET })
void uart_init();
void uart_putc(uint8_t c);
uint8_t uart_getc();
void uart_putc(uint8_t c);
#ifdef __cplusplus
} // extern "C"
#endif
#endif // _UART_REG_DEFS_

13
sdk/bsp/lib/uart.c
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@ -7,23 +7,24 @@
// send one char to uart
void uart_putc(uint8_t c)
{
while (UART0_REG(UART0_STATUS) & 0x1);
UART0_REG(UART0_TXDATA) = c;
while (UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_TXFULL_BIT));
UART0_REG(UART_TXDATA_REG_OFFSET) = c;
}
// Block, get one char from uart.
uint8_t uart_getc()
{
UART0_REG(UART0_STATUS) &= ~0x2;
while (!(UART0_REG(UART0_STATUS) & 0x2));
return (UART0_REG(UART0_RXDATA) & 0xff);
while ((UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_RXEMPTY_BIT)));
return (UART0_REG(UART_RXDATA_REG_OFFSET) & 0xff);
}
// 115200bps, 8 N 1
void uart_init()
{
// enable tx and rx
UART0_REG(UART0_CTRL) = 0x3;
UART0_REG(UART_CTRL_REG_OFFSET) |= 0x3;
xdev_out(uart_putc);
}

2
sdk/examples/uart_loopback/Makefile
View File

@ -3,7 +3,7 @@ RISCV_ABI := ilp32
RISCV_MCMODEL := medlow
TARGET = uart_rx
TARGET = uart_loopback
#CFLAGS += -DSIMULATION