From 9387f56a33518e7bb21b5bace691563befabc2da Mon Sep 17 00:00:00 2001
From: liangkangnan <liangkangnan@163.com>
Date: Fri, 13 Aug 2021 09:31:19 +0800
Subject: [PATCH] sdk:examples: add uart_int

Signed-off-by: liangkangnan <liangkangnan@163.com>
---
 sdk/examples/uart_int/.gitignore |  8 ++++
 sdk/examples/uart_int/Makefile   | 20 +++++++++
 sdk/examples/uart_int/README.md  |  1 +
 sdk/examples/uart_int/main.c     | 76 ++++++++++++++++++++++++++++++++
 4 files changed, 105 insertions(+)
 create mode 100644 sdk/examples/uart_int/.gitignore
 create mode 100644 sdk/examples/uart_int/Makefile
 create mode 100644 sdk/examples/uart_int/README.md
 create mode 100644 sdk/examples/uart_int/main.c

diff --git a/sdk/examples/uart_int/.gitignore b/sdk/examples/uart_int/.gitignore
new file mode 100644
index 0000000..bf502dc
--- /dev/null
+++ b/sdk/examples/uart_int/.gitignore
@@ -0,0 +1,8 @@
+# Object files
+*.o
+*.ko
+*.obj
+*.bin
+*.dump
+*.mem
+uart_int
diff --git a/sdk/examples/uart_int/Makefile b/sdk/examples/uart_int/Makefile
new file mode 100644
index 0000000..f7bb1d4
--- /dev/null
+++ b/sdk/examples/uart_int/Makefile
@@ -0,0 +1,20 @@
+RISCV_ARCH := rv32im
+RISCV_ABI := ilp32
+RISCV_MCMODEL := medlow
+
+
+TARGET = uart_int
+
+
+#CFLAGS += -DSIMULATION
+#CFLAGS += -O2
+#ASM_SRCS +=
+#LDFLAGS +=
+#INCLUDES += -I.
+
+C_SRCS := \
+	main.c \
+
+
+BSP_DIR = ../../bsp
+include ../../bsp/bsp.mk
diff --git a/sdk/examples/uart_int/README.md b/sdk/examples/uart_int/README.md
new file mode 100644
index 0000000..d313acc
--- /dev/null
+++ b/sdk/examples/uart_int/README.md
@@ -0,0 +1 @@
+UART发送、接收中断例程。
\ No newline at end of file
diff --git a/sdk/examples/uart_int/main.c b/sdk/examples/uart_int/main.c
new file mode 100644
index 0000000..a5cdde8
--- /dev/null
+++ b/sdk/examples/uart_int/main.c
@@ -0,0 +1,76 @@
+#include <stdint.h>
+
+#include "../../bsp/include/uart.h"
+#include "../../bsp/include/xprintf.h"
+#include "../../bsp/include/rvic.h"
+#include "../../bsp/include/utils.h"
+
+
+#define UART_TXB	(80)
+
+
+static volatile struct {
+	uint16_t	tri, twi, tct;
+	uint8_t tbuf[UART_TXB];
+} fifo;
+
+static void uart_putc(uint8_t c)
+{
+	uint16_t i;
+
+	if (fifo.tct >= UART_TXB)
+        return;
+
+	i = fifo.twi;
+	fifo.tbuf[i] = c;
+	fifo.twi = ++i % UART_TXB;
+
+    global_irq_disable();
+	fifo.tct++;
+    // 使能TX FIFO空中断
+    UART0_REG(UART_CTRL_REG_OFFSET) |= 1 << UART_CTRL_TX_FIFO_EMPTY_INT_EN_BIT;
+    global_irq_enable();
+}
+
+int main()
+{
+    uart0_init(uart_putc);
+    rvic_irq_enable(1);
+    rvic_set_irq_prio_level(1, 1);
+    // 使能RX FIFO非空中断
+    UART0_REG(UART_CTRL_REG_OFFSET) |= 1 << UART_CTRL_RX_FIFO_NOT_EMPTY_INT_EN_BIT;
+    global_irq_enable();
+    fifo.tri = 0; fifo.twi = 0; fifo.tct = 0;
+
+    xprintf("uart interrupt test\n");
+    while (1);
+}
+
+void uart0_irq_handler()
+{
+    uint16_t i, count, index;
+    uint8_t data;
+
+    // 如果RX FIFO非空
+    while (!(UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_RXEMPTY_BIT))) {
+        data = UART0_REG(UART_RXDATA_REG_OFFSET);
+        UART0_REG(UART_TXDATA_REG_OFFSET) = data;
+    }
+    // 如果TX FIFO为空
+    if ((UART0_REG(UART_STATUS_REG_OFFSET) & (1 << UART_STATUS_TXEMPTY_BIT)) &&
+        (fifo.tct > 0)) {
+
+        count = fifo.tct;
+        if (count > 8)
+            count = 8;
+        for (index = 0; index < count; index++) {
+            fifo.tct--;
+            i = fifo.tri;
+            UART0_REG(UART_TXDATA_REG_OFFSET) = fifo.tbuf[i];
+            fifo.tri = ++i % UART_TXB;
+        }
+        if (fifo.tct == 0)
+            UART0_REG(UART_CTRL_REG_OFFSET) &= ~(1 << UART_CTRL_TX_FIFO_EMPTY_INT_EN_BIT);
+    }
+    rvic_clear_irq_pending(1);
+}