sb16: cleanup and add stereo support

src/drivers/sb16.c

@@ -27,6 +27,8 @@ static bool is_playing = false;
 
 static size_t slot_sizes[2];
 
+static bool stereo = true;
+
 #define min(a, b) ((a) < (b) ? (a) : (b))
 
 void sb16_enable_irq() {
@@ -103,9 +105,6 @@ void sb16_program_dma(uint32_t buf_size)
     int buffer_pos = (uint32_t)buffer_phys + (current_slot << 15);
     int count = buf_size;
 
-    //printf("buffer_pos: %x buffer: %x\n", buffer_pos, buffer_phys);
-    //printf("buffer: 0x%x\n", ((uint32_t)buffer_phys >> 16) & 0xFF);
-
     outb(0x0A, 0x4 + channel);//0x4 + channel number (1 in this case)
     outb(0x0C, 1);//flip flop
     outb(0x0B, transfer_mode + channel);
@@ -124,16 +123,21 @@ void sb16_program_dma(uint32_t buf_size)
 
 void sb16_program(uint32_t buf_size)
 {
-    const int samples_count = buf_size;
+    const int samples_count = stereo ? buf_size / 2 : buf_size;
     outb(DSP_WRITE, 0x41);//sample rate
 
     const int sample_rate = 44100;
     outb(DSP_WRITE, (sample_rate >> 8) & 0xff);
     outb(DSP_WRITE, (sample_rate) & 0xff);
 
+    uint8_t mode = 0x0;
+    if(stereo)
+    {
+        mode |= (1 << 5);//set the 5th bit to 1 if stereo
+    }
 
     outb(DSP_WRITE, 0xC0);//8-bit sound
-    outb(DSP_WRITE, 0x00);//mono unsigned
+    outb(DSP_WRITE, mode);
     outb(DSP_WRITE, (samples_count - 1) & 0xFF);
     outb(DSP_WRITE, ((samples_count - 1) >> 8) & 0xFF);
 }
@@ -235,7 +239,4 @@ void sb16_init()
 
     outb(MIXER, 0x80);
     printf("SB16 raw irq_code: 0x%X\n", inb(MIXER_DATA));
-
-    //sb16_program_dma();
-    //sb16_program();
 }