Clean up io/system573 example and libpsxpress

2 files changed, 19 insertions, 15 deletions

diff --git a/libpsn00b/include/psxpress.h b/libpsn00b/include/psxpress.h
index b060170..6203c2a 100644
--- a/libpsn00b/include/psxpress.h
+++ b/libpsn00b/include/psxpress.h
@@ -40,7 +40,7 @@ extern "C" {
  *
  * @param mode
  */
-void DecDCTReset(int32_t mode);
+void DecDCTReset(int mode);
 
 /**
  * @brief Uploads the specified decoding environment's quantization tables and
@@ -61,7 +61,7 @@ void DecDCTReset(int32_t mode);
  * @param env Pointer to DECDCTENV or 0 for default tables
  * @param mono 0 for color (normal), 1 for monochrome
  */
-void DecDCTPutEnv(const DECDCTENV *env, int32_t mono);
+void DecDCTPutEnv(const DECDCTENV *env, int mono);
 
 /**
  * @brief Sets up the MDEC to start fetching and decoding a stream from the
@@ -79,7 +79,7 @@ void DecDCTPutEnv(const DECDCTENV *env, int32_t mono);
  * @param data
  * @param mode DECDCT_MODE_* or -1
  */
-void DecDCTin(const uint32_t *data, int32_t mode);
+void DecDCTin(const uint32_t *data, int mode);
 
 /**
  * @brief Configures the MDEC to automatically fetch data (the input stream,
@@ -113,7 +113,7 @@ void DecDCTinRaw(const uint32_t *data, size_t length);
  * @param mode
  * @return 0 or -1 in case of a timeout (mode = 0) / MDEC busy flag (mode = 1)
  */
-int32_t DecDCTinSync(int32_t mode);
+int DecDCTinSync(int mode);
 
 /**
  * @brief Configures the MDEC to automatically transfer decoded image data in
@@ -144,7 +144,7 @@ void DecDCTout(uint32_t *data, size_t length);
  * @param mode
  * @return 0 or -1 in case of a timeout (mode = 0) / DMA busy flag (mode = 1)
  */
-int32_t DecDCToutSync(int32_t mode);
+int DecDCToutSync(int mode);
 
 #ifdef __cplusplus
 }
diff --git a/libpsn00b/psxpress/mdec.c b/libpsn00b/psxpress/mdec.c
index ca4c75a..ba190d4 100644
--- a/libpsn00b/psxpress/mdec.c
+++ b/libpsn00b/psxpress/mdec.c
@@ -9,7 +9,8 @@
 #include <psxpress.h>
 #include <hwregs_c.h>
 
-#define MDEC_SYNC_TIMEOUT 0x1000000
+#define DMA_CHUNK_LENGTH	32
+#define MDEC_SYNC_TIMEOUT	0x1000000
 
 /* Default IDCT matrix and quantization tables */
 
@@ -82,7 +83,7 @@ static const DECDCTENV _default_mdec_env = {
 
 /* Public API */
 
-void DecDCTReset(int32_t mode) {
+void DecDCTReset(int mode) {
 	EnterCriticalSection();
 
 	DMA_DPCR   |= 0x000000bb; // Enable DMA0 and DMA1
@@ -96,7 +97,7 @@ void DecDCTReset(int32_t mode) {
 		DecDCTPutEnv(0, 0);
 }
 
-void DecDCTPutEnv(const DECDCTENV *env, int32_t mono) {
+void DecDCTPutEnv(const DECDCTENV *env, int mono) {
 	const DECDCTENV *_env = env ? env : &_default_mdec_env;
 	DecDCTinSync(0);
 
@@ -109,7 +110,7 @@ void DecDCTPutEnv(const DECDCTENV *env, int32_t mono) {
 	DecDCTinSync(0);
 }
 
-void DecDCTin(const uint32_t *data, int32_t mode) {
+void DecDCTin(const uint32_t *data, int mode) {
 	uint32_t header = *data;
 	if (mode == DECDCT_MODE_RAW)
 		MDEC0 = header;
@@ -125,16 +126,19 @@ void DecDCTin(const uint32_t *data, int32_t mode) {
 // data length as an argument rather than parsing it from the first 4 bytes of
 // the stream.
 void DecDCTinRaw(const uint32_t *data, size_t length) {
+	// NOTE: if length >= DMA_CHUNK_LENGTH then it also has to be a multiple of
+	// DMA_CHUNK_LENGTH, otherwise the DMA channel will get stuck waiting for
+	// more data indefinitely.
 	DMA_MADR(0) = (uint32_t) data;
-	if (length < 32)
+	if (length < DMA_CHUNK_LENGTH)
 		DMA_BCR(0) = 0x00010000 | length;
 	else
-		DMA_BCR(0) = 0x00000020 | ((length / 32) << 16);
+		DMA_BCR(0) = DMA_CHUNK_LENGTH | ((length / DMA_CHUNK_LENGTH) << 16);
 
 	DMA_CHCR(0) = 0x01000201;
 }
 
-int32_t DecDCTinSync(int32_t mode) {
+int DecDCTinSync(int mode) {
 	if (mode)
 		return (MDEC1 >> 29) & 1;
 
@@ -151,15 +155,15 @@ void DecDCTout(uint32_t *data, size_t length) {
 	DecDCToutSync(0);
 
 	DMA_MADR(1) = (uint32_t) data;
-	if (length < 32)
+	if (length < DMA_CHUNK_LENGTH)
 		DMA_BCR(1) = 0x00010000 | length;
 	else
-		DMA_BCR(1) = 0x00000020 | ((length / 32) << 16);
+		DMA_BCR(1) = DMA_CHUNK_LENGTH | ((length / DMA_CHUNK_LENGTH) << 16);
 
 	DMA_CHCR(1) = 0x01000200;
 }
 
-int32_t DecDCToutSync(int32_t mode) {
+int DecDCToutSync(int mode) {
 	if (mode)
 		return (DMA_CHCR(1) >> 24) & 1;