cleaned up the irq/dma detect code

diff --git a/src/au_sb.c b/src/au_sb.c
index 3e27e2f..1adcfc1 100644 (file)
--- a/src/au_sb.c
+++ b/src/au_sb.c
@@ -77,6 +77,8 @@ static unsigned char read_dsp(void);
 static void write_mix(unsigned char val, int reg);
 static unsigned char read_mix(int reg);
 static int get_dsp_version(void);
+static int sb16_detect_irq(void);
+static int sb16_detect_dma(void);
 static const char *sbname(int ver);
 
 extern unsigned char low_mem_buffer[];
@@ -89,9 +91,7 @@ static int xfer_mode;
 
 int sb_detect(void)
 {
-       int i, j, ver, tmp, irqsel, dmasel;
-       static int irqtab[] = {2, 5, 7, 10};
-       static int dmatab[] = {0, 1, -1, 3, -1, 5, 6, 7};
+       int i, ver;
 
        for(i=0; i<6; i++) {
                base_port = 0x200 + ((i + 1) << 4);
@@ -100,62 +100,13 @@ int sb_detect(void)
                        sb16 = VER_MAJOR(ver) >= 4;
 
                        if(sb16) {
-                               irq = 0;
-                               irqsel = read_mix(MIX_IRQ_SEL);
-                               for(j=0; j<4; j++) {
-                                       if(irqsel & (1 << j)) {
-                                               irq = irqtab[j];
-                                               break;
-                                       }
-                               }
-                               if(!irq) {
-                                       /* try to force IRQ 5 */
-                                       write_mix(2, MIX_IRQ_SEL);      /* bit1 selects irq 5 */
-
-                                       /* re-read to verify */
-                                       irqsel = read_mix(MIX_IRQ_SEL);
-                                       if(irqsel != 2) {
-                                               printf("sb_detect: failed to configure IRQ\n");
-                                               return 0;
-                                       }
-                                       irq = 5;
-                               }
-
-                               dma_chan = -1;
-                               dma16_chan = -1;
-                               dmasel = read_mix(MIX_DMA_SEL);
-                               for(j=0; j<4; j++) {
-                                       if(dmasel & (1 << j)) {
-                                               dma_chan = dmatab[j];
-                                               break;
-                                       }
-                               }
-                               for(j=5; j<8; j++) {
-                                       if(dmasel & (1 << j)) {
-                                               dma16_chan = dmatab[j];
-                                               break;
-                                       }
-                               }
-                               if(dma_chan == -1) {
-                                       /* try to force DMA 1 */
-                                       dmasel |= 2;
+                               if(sb16_detect_irq() == -1) {
+                                       printf("sb_detect: failed to configure IRQ\n");
+                                       return 0;
                                }
-                               if(dma16_chan == -1) {
-                                       /* try to force 16bit DMA 5 */
-                                       dmasel |= 0x20;
-                               }
-
-                               if(dma_chan == -1 || dma16_chan == -1) {
-                                       write_mix(dmasel, MIX_DMA_SEL);
-
-                                       /* re-read to verify */
-                                       tmp = read_mix(MIX_DMA_SEL);
-                                       if(tmp != dmasel) {
-                                               printf("sb_detect: failed to configure DMA\n");
-                                               return 0;
-                                       }
-                                       dma_chan = 1;
-                                       dma16_chan = 5;
+                               if(sb16_detect_dma() == -1) {
+                                       printf("sb_detect: failed to configure DMA\n");
+                                       return 0;
                                }
 
                                printf("sb_detect: found %s (DSP v%d.%02d) at port %xh, irq %d, dma %d/%d\n",
@@ -332,6 +283,78 @@ static int get_dsp_version(void)
        return (major << 8) | minor;
 }
 
+static int sb16_detect_irq(void)
+{
+       int i, irqsel;
+       static int irqtab[] = {2, 5, 7, 10};
+
+       irq = 0;
+       irqsel = read_mix(MIX_IRQ_SEL);
+       for(i=0; i<4; i++) {
+               if(irqsel & (1 << i)) {
+                       irq = irqtab[i];
+                       break;
+               }
+       }
+       if(!irq) {
+               /* try to force IRQ 5 */
+               write_mix(2, MIX_IRQ_SEL);      /* bit1 selects irq 5 */
+
+               /* re-read to verify */
+               irqsel = read_mix(MIX_IRQ_SEL);
+               if(irqsel != 2) {
+                       return -1;
+               }
+               irq = 5;
+       }
+
+       return irq;
+}
+
+static int sb16_detect_dma(void)
+{
+       int i, dmasel, tmp;
+       static int dmatab[] = {0, 1, -1, 3, -1, 5, 6, 7};
+
+       dma_chan = -1;
+       dma16_chan = -1;
+       dmasel = read_mix(MIX_DMA_SEL);
+       for(i=0; i<4; i++) {
+               if(dmasel & (1 << i)) {
+                       dma_chan = dmatab[i];
+                       break;
+               }
+       }
+       for(i=5; i<8; i++) {
+               if(dmasel & (1 << i)) {
+                       dma16_chan = dmatab[i];
+                       break;
+               }
+       }
+       if(dma_chan == -1) {
+               /* try to force DMA 1 */
+               dmasel |= 2;
+       }
+       if(dma16_chan == -1) {
+               /* try to force 16bit DMA 5 */
+               dmasel |= 0x20;
+       }
+
+       if(dma_chan == -1 || dma16_chan == -1) {
+               write_mix(dmasel, MIX_DMA_SEL);
+
+               /* re-read to verify */
+               tmp = read_mix(MIX_DMA_SEL);
+               if(tmp != dmasel) {
+                       return -1;
+               }
+               dma_chan = 1;
+               dma16_chan = 5;
+       }
+
+       return dma_chan;
+}
+
 #define V(maj, min)    (((maj) << 8) | (min))
 
 static const char *sbname(int ver)