[feat] 简易鼠标驱动

2026-06-06 11:32:08 +08:00
parent 866c3e4d03
commit 3bece9e75e
7 changed files with 326 additions and 24 deletions
@@ -0,0 +1,170 @@
+#include <devices/mouse.h>
+#include <interrupt/idt.h>
+#include <interrupt/pic.h>
+#include <serial.h>
+
+static inline void outb(UINT16 port, UINT8 val) {
+    ASM("outb %0, %1" : : "a"(val), "Nd"(port));
+}
+
+static inline UINT8 inb(UINT16 port) {
+    UINT8 ret;
+    ASM("inb %1, %0" : "=a"(ret) : "Nd"(port));
+    return ret;
+}
+
+// 等待 PS/2 控制器输入缓冲区清空
+static void ps2_wait_input(void) {
+    for (int i = 0; i < 100000; i++) {
+        if (!(inb(PS2_STATUS_PORT) & PS2_STAT_IBF)) return;
+    }
+}
+
+// 等待 PS/2 控制器输出缓冲区有数据
+static void ps2_wait_output(void) {
+    for (int i = 0; i < 100000; i++) {
+        if (inb(PS2_STATUS_PORT) & PS2_STAT_OBF) return;
+    }
+}
+
+// 向 PS/2 控制器发送命令
+static void ps2_write_cmd(UINT8 cmd) {
+    ps2_wait_input();
+    outb(PS2_CMD_PORT, cmd);
+}
+
+// 读取 PS/2 控制器返回的数据
+static UINT8 ps2_read_data(void) {
+    ps2_wait_output();
+    return inb(PS2_DATA_PORT);
+}
+
+// 向辅助端口（鼠标）发送数据
+static void ps2_write_mouse(UINT8 data) {
+    ps2_write_cmd(0xD4);  // Write to Auxiliary Device
+    ps2_wait_input();
+    outb(PS2_DATA_PORT, data);
+}
+
+// 鼠标 3 字节数据包状态
+static int    g_pkt_phase = 0;     // 0=byte0, 1=byte1, 2=byte2
+static UINT8  g_pkt_byte0 = 0;
+static UINT8  g_pkt_byte1 = 0;
+
+// 鼠标光标位置（相对于屏幕中心）
+static volatile SSINT32 g_mouse_x = 0;
+static volatile SSINT32 g_mouse_y = 0;
+static volatile bool    g_mouse_btn_l = false;
+static volatile bool    g_mouse_btn_r = false;
+static volatile bool    g_mouse_btn_m = false;
+
+// IRQ12 处理函数
+static void mouse_irq_handler(trap_frame* frame) {
+    (void)frame;
+    pic_send_eoi(PS2_MOUSE_IRQ);
+
+    // 读取状态寄存器，检查输出缓冲区是否有数据
+    UINT8 status = inb(PS2_STATUS_PORT);
+    if (!(status & PS2_STAT_OBF)) return;
+
+    UINT8 data = inb(PS2_DATA_PORT);
+
+    // 解析 3 字节数据包
+    switch (g_pkt_phase) {
+        case 0:  // byte 0: 按钮 + 标志
+            if (!(data & PS2_MOUSE_ALWAYS1)) return;  // 无效字节，重新同步
+            g_pkt_byte0 = data;
+            g_pkt_phase = 1;
+            break;
+        case 1:  // byte 1: X delta
+            g_pkt_byte1 = data;
+            g_pkt_phase = 2;
+            break;
+        case 2:  // byte 2: Y delta
+            g_pkt_byte0 = g_pkt_byte0;  // 确保编译器不优化
+            g_pkt_byte1 = g_pkt_byte1;
+
+            // 解析按钮状态
+            g_mouse_btn_l = (g_pkt_byte0 & PS2_MOUSE_LEFT)   != 0;
+            g_mouse_btn_r = (g_pkt_byte0 & PS2_MOUSE_RIGHT)  != 0;
+            g_mouse_btn_m = (g_pkt_byte0 & PS2_MOUSE_MIDDLE) != 0;
+
+            // 解析 X delta
+            SSINT32 dx = (SSINT32)(SSINT8)g_pkt_byte1;
+            if (g_pkt_byte0 & PS2_MOUSE_X_SIGN) dx |= 0xFFFFFF00;
+
+            // 解析 Y delta
+            SSINT32 dy = (SSINT32)(SSINT8)data;
+            if (g_pkt_byte0 & PS2_MOUSE_Y_SIGN) dy |= 0xFFFFFF00;
+
+            // 更新光标位置（Y 轴在屏幕上向下为正）
+            g_mouse_x += dx;
+            g_mouse_y -= dy;
+
+            g_pkt_phase = 0;
+            break;
+    }
+}
+
+// 丢弃输出缓冲区中的残留数据
+static void ps2_flush_output(void) {
+    for (int i = 0; i < 100; i++) {
+        inb(PS2_DATA_PORT);
+    }
+}
+
+void mouse_init(void) {
+    // 1. 控制器自检（必须在命令字节写入之前，因为自检会重置命令字节）
+    ps2_write_cmd(PS2_CMD_SELF_TEST);
+    UINT8 self_test = ps2_read_data();
+    if (self_test != 0x55) {
+        serial_write("MOUSE: self-test FAILED\n");
+    }
+
+    // 2. 丢弃自检可能产生的残留数据
+    ps2_flush_output();
+
+    // 3. 启用辅助端口（鼠标）
+    ps2_write_cmd(PS2_CMD_ENABLE_A2);
+
+    // 4. 读取当前命令字节
+    ps2_write_cmd(PS2_CMD_READ_MB);
+    UINT8 cmd = ps2_read_data();
+
+    // 5. 启用 IRQ12 + IRQ1
+    cmd |= PS2_CMD_IRQ12 | PS2_CMD_IRQ1;
+
+    // 6. 写入修改后的命令字节（在自检之后，不会被重置）
+    ps2_write_cmd(PS2_CMD_WRITE_MB);
+    ps2_wait_input();
+    outb(PS2_DATA_PORT, cmd);
+
+    // 7. 验证命令字节已写入
+    ps2_write_cmd(PS2_CMD_READ_MB);
+    UINT8 verify = ps2_read_data();
+    if (verify != cmd) {
+        serial_write("MOUSE: cmd verify mismatch\n");
+    }
+
+    // 重置鼠标
+    ps2_write_mouse(PS2_MOUSE_RESET);
+    UINT8 ack = ps2_read_data();
+    if (ack == 0xFA) {
+        ps2_read_data(); // 丢弃第二字节
+    }
+
+    // 启用鼠标数据上报
+    ps2_write_mouse(PS2_MOUSE_ENABLE);
+    ps2_read_data();
+
+    // 注册 IRQ12 处理函数并取消屏蔽
+    idt_set_handler(PS2_MOUSE_VECTOR, mouse_irq_handler);
+    pic_unmask_irq(2);   // 取消主片级联屏蔽
+    pic_unmask_irq(PS2_MOUSE_IRQ);
+}
+
+SSINT32 mouse_get_x(void) { return g_mouse_x; }
+SSINT32 mouse_get_y(void) { return g_mouse_y; }
+bool    mouse_get_btn_left(void)   { return g_mouse_btn_l; }
+bool    mouse_get_btn_right(void)  { return g_mouse_btn_r; }
+bool    mouse_get_btn_middle(void) { return g_mouse_btn_m; }