Refactor libpsxcd, add new CD-ROM APIs, fix SPU DMA read

1 files changed, 168 insertions, 0 deletions

diff --git a/libpsn00b/psxcd/cdread.c b/libpsn00b/psxcd/cdread.c
new file mode 100644
index 0000000..d211a01
--- /dev/null
+++ b/libpsn00b/psxcd/cdread.c
@@ -0,0 +1,168 @@
+/*
+ * PSn00bSDK CD-ROM library (high-level reading API)
+ * (C) 2020-2022 Lameguy64, spicyjpeg - MPL licensed
+ *
+ * CdRead() and its related functions are separate from the "main" psxcd code
+ * since handling retries is fairly complicated. In particular the drive
+ * controller will not process any command properly for some time after a
+ * CdlPause command, so an external timer (the vblank counter) and manual
+ * polling are required to defer the next attempt.
+ */
+
+#include <stdint.h>
+#include <assert.h>
+#include <psxgpu.h>
+#include <psxapi.h>
+#include <psxcd.h>
+
+#define CD_READ_TIMEOUT		180
+#define CD_READ_COOLDOWN	60
+
+/* Internal globals */
+
+static CdlCB _read_callback = (CdlCB) 0;
+
+static int     _total_sectors, _sector_size;
+static uint8_t _read_result[4];
+
+static volatile uint32_t *_read_addr;
+static volatile int      _read_timeout, _pending_attempts, _pending_sectors;
+
+extern CdlCB _cd_override_callback;
+
+/* Private utilities and sector callback */
+
+static void _sector_callback(CdlIntrResult irq, uint8_t *result) {
+	if (irq == CdlDataReady) {
+		CdGetSector((void *) _read_addr, _sector_size);
+		_read_addr += _sector_size;
+
+		if (--_pending_sectors > 0) {
+			_read_timeout = VSync(-1) + CD_READ_TIMEOUT;
+			return;
+		}
+	}
+
+	// Stop reading if an error occurred or if no more sectors need to be read.
+	CdCommandF(CdlPause, 0, 0);
+
+	_cd_override_callback = (CdlCB) 0;
+	if (!_pending_attempts && _read_callback)
+		_read_callback(irq, result);
+
+	_read_timeout = VSync(-1) + CD_READ_COOLDOWN;
+}
+
+static int _poll_retry(void) {
+	if (!_pending_attempts) {
+		_sdk_log("CdRead() failed, too many attempts\n");
+
+		_pending_sectors = 0;
+		return -1;
+	}
+
+	//CdControlB(CdlPause, 0, 0);
+
+	_sdk_log("CdRead() failed, retrying (%d sectors pending)\n", _pending_sectors);
+	_pending_attempts--;
+
+	// Restart from the first sector that returned an error.
+	CdlLOC pos;
+	CdIntToPos(
+		CdPosToInt(CdLastPos()) + _total_sectors - _pending_sectors,
+		&pos
+	);
+
+	_read_timeout  = VSync(-1) + CD_READ_TIMEOUT;
+	_total_sectors = _pending_sectors;
+
+	FastEnterCriticalSection();
+	_cd_override_callback = &_sector_callback;
+	FastExitCriticalSection();
+
+	if (CdCommand(CdlSetloc, (uint8_t *) &pos, 3, _read_result))
+		CdCommand(CdlReadN, 0, 0, _read_result);
+
+	return _pending_sectors;
+}
+
+/* Public API */
+
+int CdReadRetry(int sectors, uint32_t *buf, int mode, int attempts) {
+	if (CdReadSync(1, 0) > 0) {
+		_sdk_log("CdRead() failed, another read in progress (%d sectors pending)\n", _pending_sectors);
+		return 0;
+	}
+
+	_read_addr        = buf;
+	_read_timeout     = VSync(-1) + CD_READ_TIMEOUT;
+	_pending_attempts = attempts - 1;
+	_pending_sectors  = sectors;
+	_total_sectors    = sectors;
+	_sector_size      = (mode & CdlModeSize) ? 585 : 512;
+
+	FastEnterCriticalSection();
+	_cd_override_callback = &_sector_callback;
+	FastExitCriticalSection();
+
+	uint8_t _mode = mode;
+	if (!CdCommand(CdlSetmode, &_mode, 1, 0))
+		return 0;
+	if (!CdCommand(CdlReadN, 0, 0, _read_result))
+		return 0;
+
+	return 1;
+}
+
+int CdRead(int sectors, uint32_t *buf, int mode) {
+	return CdReadRetry(sectors, buf, mode, 1);
+}
+
+void CdReadBreak(void) {
+	if (_pending_sectors > 0)
+		_pending_sectors = -1;
+}
+
+int CdReadSync(int mode, uint8_t *result) {
+	if (mode) {
+		if (_pending_sectors < 0)
+			return -2;
+		if (!_pending_sectors)
+			return 0;
+
+		if (VSync(-1) > _read_timeout)
+			return _poll_retry();
+		if (CdSync(1, 0) == CdlDiskError)
+			return -1;
+
+		return _pending_sectors;
+	}
+
+	while (_pending_sectors > 0) {
+		if (VSync(-1) > _read_timeout) {
+			if (_poll_retry() < 0)
+				return -1;
+		}
+
+		//if (CdSync(1, 0) == CdlDiskError)
+			//return -1;
+	}
+
+	CdlIntrResult status = CdSync(0, result);
+	if (_pending_sectors < 0)
+		return -2;
+	if (status != CdlComplete)
+		return -1;
+
+	return 0;
+}
+
+CdlCB CdReadCallback(CdlCB func) {
+	FastEnterCriticalSection();
+
+	CdlCB old_callback = _read_callback;
+	_read_callback     = func;
+
+	FastExitCriticalSection();
+	return old_callback;
+}