sb16: continue trying to add a driver

src/drivers/sb16.c

@@ -49,11 +49,13 @@ int sb16_get_irq()
     return irq;
 }
 
+void* buffer;
+
 void* sb16_allocate_buf()
 {
     const size_t size = 64*1024;//64 KB
 
-    void* buffer = malloc(size);
+    buffer = malloc(size);
 
     return get_physaddr(buffer);
 }
@@ -66,6 +68,42 @@ void sb16_get_version(int* major, int* minor)
     *minor = inb(DSP_READ);
 }
 
+void sb16_program_dma()
+{
+    const int transfer_mode = 0x48;
+    const int channel = 1;
+    const int page_number = 0;//page that contains sound data
+
+    int buffer_pos = (uint32_t)buffer & 0xffff;
+    int count = 0;
+
+    outb(0x0A, 0x4 + channel);//0x4 + channel number (1 in this case)
+    outb(0x0C, 1);//flip flop
+    outb(0x0B, transfer_mode + channel);
+    outb(0x83, page_number);
+
+    //set the position
+    outb(0x02, (buffer_pos) & 0xFF);
+    outb(0x02, (buffer_pos >> 8) & 0xFF);
+
+    //set the count
+    outb(0x03, (count - 1) & 0xFF);
+    outb(0x03, ((count - 1) >> 8) & 0xFF);
+
+    outb(0x0A, 1);
+}
+
+void sb16_program()
+{
+    const int samples_count = 0;
+    outb(DSP_WRITE, 0x40);//time constant
+    outb(DSP_WRITE, 165);//10989 Hz
+    outb(DSP_WRITE, 0xC0);//8-bit sound
+    outb(DSP_WRITE, 0x00);//mono unsigned
+    outb(DSP_WRITE, (samples_count - 1) & 0xFF);
+    outb(DSP_WRITE, ((samples_count - 1) >> 8) & 0xFF);
+}
+
 void sb16_init()
 {
     int status = sb16_dsp_reset();
@@ -80,4 +118,7 @@ void sb16_init()
     printf("sb16 version: %X.%X\n", major, minor);
 
     outb(DSP_WRITE, 0xD1);//enable speaker
+
+    sb16_program_dma();
+    sb16_program();
 }