+#include <stdio.h>
+#include <dos.h>
+#include <pc.h>
+#include <go32.h>
+#include <dpmi.h>
+#include "audio.h"
+#include "au_sb.h"
+#include "dma.h"
+
+#define IRQ_TO_INTR(x) ((x) + 8)
+
+/* PIC command and data ports */
+#define PIC1_CMD 0x20
+#define PIC1_DATA 0x21
+#define PIC2_CMD 0xa0
+#define PIC2_DATA 0xa1
+/* PIC operation command word 2 bits */
+#define OCW2_EOI (1 << 5)
+
+#define REG_MIXPORT (base_port + 0x4)
+#define REG_MIXDATA (base_port + 0x5)
+#define REG_RESET (base_port + 0x6)
+#define REG_RDATA (base_port + 0xa)
+#define REG_WDATA (base_port + 0xc)
+#define REG_WSTAT (base_port + 0xc)
+#define REG_RSTAT (base_port + 0xe)
+#define REG_INTACK (base_port + 0xe)
+#define REG_INT16ACK (base_port + 0xf)
+
+#define WSTAT_BUSY 0x80
+#define RSTAT_RDY 0x80
+
+#define CMD_RATE 0x40
+#define CMD_SB16_OUT_RATE 0x41
+#define CMD_SB16_IN_RATE 0x42
+#define CMD_GET_VER 0xe1
+
+/* start DMA playback/recording. combine with fifo/auto/input flags */
+#define CMD_START_DMA8 0xc0
+#define CMD_START_DMA16 0xb0
+#define CMD_FIFO 0x02
+#define CMD_AUTO 0x04
+#define CMD_INPUT 0x08
+
+/* immediately pause/continue */
+#define CMD_PAUSE_DMA8 0xd0
+#define CMD_ENABLE_OUTPUT 0xd1
+#define CMD_DISABLE_OUTPUT 0xd3
+#define CMD_CONT_DMA8 0xd4
+#define CMD_PAUSE_DMA16 0xd5
+#define CMD_CONT_DMA16 0xd6
+
+/* end the playback at the end of the current buffer */
+#define CMD_END_DMA16 0xd9
+#define CMD_END_DMA8 0xda
+
+/* transfer mode commands */
+#define CMD_MODE_SIGNED 0x10
+#define CMD_MODE_STEREO 0x20
+
+/* mixer registers */
+#define MIX_IRQ_SEL 0x80
+#define MIX_DMA_SEL 0x81
+
+#define VER_MAJOR(x) ((x) >> 8)
+#define VER_MINOR(x) ((x) & 0xff)
+
+/* delay for about 1us */
+#define iodelay() outportb(0x80, 0)
+
+static void intr_handler();
+static void start_dma_transfer(uint32_t addr, int size);
+static void write_dsp(unsigned char val);
+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[];
+
+static int base_port;
+static int irq, dma_chan, dma16_chan;
+static int sb16;
+static void *buffer;
+static int xfer_mode;
+
+int sb_detect(void)
+{
+ int i, ver;
+
+ for(i=0; i<6; i++) {
+ base_port = 0x200 + ((i + 1) << 4);
+ if(sb_reset_dsp() == 0) {
+ ver = get_dsp_version();
+ sb16 = VER_MAJOR(ver) >= 4;
+
+ if(sb16) {
+ if(sb16_detect_irq() == -1) {
+ printf("sb_detect: failed to configure IRQ\n");
+ return 0;
+ }
+ 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",
+ sbname(ver), VER_MAJOR(ver), VER_MINOR(ver),
+ base_port, irq, dma_chan, dma16_chan);
+
+ } else {
+ /* XXX for old sound blasters, hard-code to IRQ 5 DMA 1 for now */
+ irq = 5;
+ dma_chan = 1;
+ dma16_chan = -1;
+
+ printf("sb_detect: found %s (DSP v%d.%02d) at port %xh\n", sbname(ver),
+ VER_MAJOR(ver), VER_MINOR(ver), base_port);
+ printf("sb_detect: old sound blaster dsp. assuming: irq 5, dma 1\n");
+ }
+
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+int sb_reset_dsp(void)
+{
+ int i;
+
+ outportb(REG_RESET, 1);
+ for(i=0; i<3; i++) iodelay();
+ outportb(REG_RESET, 0);
+
+ for(i=0; i<128; i++) {
+ if(inportb(REG_RSTAT) & RSTAT_RDY) {
+ if(inportb(REG_RDATA) == 0xaa) {
+ return 0;
+ }
+ }
+ }
+
+ return -1;
+}
+
+void sb_set_output_rate(int rate)
+{
+ if(sb16) {
+ write_dsp(CMD_SB16_OUT_RATE);
+ write_dsp(rate >> 8);
+ write_dsp(rate & 0xff);
+ } else {
+ int tcon = 256 - 1000000 / rate;
+ write_dsp(CMD_RATE);
+ write_dsp(tcon);
+ }
+}
+
+void *sb_buffer(int *size)
+{
+ *size = 65536;
+ return buffer;
+}
+
+void sb_start(int rate, int nchan)
+{
+ uint32_t addr;
+ int size;
+ _go32_dpmi_seginfo intr;
+
+ /* for now just use the are after boot2. it's only used by the second stage
+ * loader and the VBE init code, none of which should overlap with audio playback.
+ * It's not necessary to use low memory. We can use up to the first 16mb for this,
+ * so if this becomes an issue, I'll make a DMA buffer allocator over 1mb.
+ * start the buffer from the next 64k boundary.
+ */
+ addr = ((uint32_t)low_mem_buffer + 0xffff) & 0xffff0000;
+ buffer = (void*)addr;
+
+ xfer_mode = CMD_MODE_SIGNED;
+ if(nchan > 1) {
+ xfer_mode |= CMD_MODE_STEREO;
+ }
+
+ if(!(size = audio_callback(buffer, 65536))) {
+ return;
+ }
+
+ intr.pm_offset = (intptr_t)intr_handler;
+ intr.pm_selector = _go32_my_cs();
+ _disable();
+ _go32_dpmi_set_protected_mode_interrupt_vector(IRQ_TO_INTR(irq), &intr);
+ _enable();
+
+ sb_set_output_rate(rate);
+ start_dma_transfer(addr, size);
+ write_dsp(CMD_ENABLE_OUTPUT);
+}
+
+void sb_pause(void)
+{
+ write_dsp(CMD_PAUSE_DMA8);
+}
+
+void sb_continue(void)
+{
+ write_dsp(CMD_CONT_DMA8);
+}
+
+void sb_stop(void)
+{
+ write_dsp(CMD_END_DMA8);
+ write_dsp(CMD_DISABLE_OUTPUT);
+}
+
+void sb_volume(int vol)
+{
+ /* TODO */
+}
+
+static void intr_handler()
+{
+ int size;
+
+ /* ask for more data */
+ if(!(size = audio_callback(buffer, 65536))) {
+ sb_stop();
+ return;
+ }
+ start_dma_transfer((uint32_t)buffer, size);
+
+ /* acknowledge the interrupt */
+ inportb(REG_INTACK);
+
+ if(irq > 7) {
+ outportb(PIC2_CMD, OCW2_EOI);
+ }
+ outportb(PIC1_CMD, OCW2_EOI);
+}
+
+static void start_dma_transfer(uint32_t addr, int size)
+{
+ /* set up the next DMA transfer */
+ dma_out(dma_chan, addr, size, DMA_SINGLE);
+
+ /* program the DSP to accept the DMA transfer */
+ write_dsp(CMD_START_DMA8 | CMD_FIFO);
+ write_dsp(xfer_mode);
+ size--;
+ write_dsp(size & 0xff);
+ write_dsp((size >> 8) & 0xff);
+}
+
+static void write_dsp(unsigned char val)
+{
+ while(inportb(REG_WSTAT) & WSTAT_BUSY);
+ outportb(REG_WDATA, val);
+}
+
+static unsigned char read_dsp(void)
+{
+ while((inportb(REG_RSTAT) & RSTAT_RDY) == 0);
+ return inportb(REG_RDATA);
+}
+
+static void write_mix(unsigned char val, int reg)
+{
+ outportb(REG_MIXPORT, reg);
+ outportb(REG_MIXDATA, val);
+}
+
+static unsigned char read_mix(int reg)
+{
+ outportb(REG_MIXPORT, reg);
+ return inportb(REG_MIXDATA);
+}
+
+static int get_dsp_version(void)
+{
+ int major, minor;
+
+ write_dsp(CMD_GET_VER);
+ major = read_dsp();
+ minor = read_dsp();
+
+ 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)
+{
+ int major = VER_MAJOR(ver);
+ int minor = VER_MINOR(ver);
+
+ switch(major) {
+ case 1:
+ if(minor == 5) {
+ return "Sound Blaster 1.5";
+ }
+ return "Sound Blaster 1.0";
+
+ case 2:
+ if(minor == 1 || minor == 2) {
+ return "Sound Blaster 2.0";
+ }
+ break;
+
+ case 3:
+ switch(minor) {
+ case 0:
+ return "Sound Blaster Pro";
+ case 1:
+ case 2:
+ return "Sound Blaster Pro 2";
+ case 5:
+ return "Gallant SC-6000";
+ default:
+ break;
+ }
+ break;
+
+ case 4:
+ switch(minor) {
+ case 4:
+ case 5:
+ return "Sound Blaster 16";
+ case 11:
+ return "Sound Blaster 16 SCSI-2";
+ case 12:
+ return "Sound Blaster AWE 32";
+ case 13:
+ return "Sound Blaster ViBRA16C";
+ case 16:
+ return "Sound Blaster AWE 64";
+ default:
+ break;
+ }
+ break;
+ }
+
+ return "Unknown Sound Blaster";
+}
projects / dos_sbtest / commitdiff