e200: Use 16-16 L-R pairs when writing to the TX FIFO. Kill the channel swapping and clicks. Reduce number of FIQs. Should be adaptable to iPods and other PP targets in a few minutes work, eh?

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@13463 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 67 insertions, 16 deletions

diff --git a/firmware/target/arm/i2s-pp.c b/firmware/target/arm/i2s-pp.c
index a2a74bf72b..c63287b72b 100644
--- a/firmware/target/arm/i2s-pp.c
+++ b/firmware/target/arm/i2s-pp.c
@@ -46,20 +46,58 @@ void i2s_reset(void)
 }
 #else /* PP502X */
 
+/* All I2S formats send MSB first */
+
 /* Data format on the I2S bus */
-#define FORMAT_MASK (0x3 << 10)
-#define FORMAT_I2S  (0x00 << 10)
-/* Other formats not yet known */
+#define FORMAT_MASK  (0x3 << 10)
+#define FORMAT_I2S   (0x0 << 10) /* Standard I2S - leading dummy bit */
+#define FORMAT_1     (0x1 << 10)
+#define FORMAT_LJUST (0x2 << 10) /* Left justified - no dummy bit */
+#define FORMAT_3     (0x3 << 10)
+/* Other formats not yet known  */
 
 /* Data size on I2S bus */
 #define SIZE_MASK   (0x3 << 8)
-#define SIZE_16BIT  (0x00 << 10)
+#define SIZE_16BIT  (0x0 << 8)
 /* Other sizes not yet known */
 
 /* Data size/format on I2S FIFO */
-#define FIFO_FORMAT_MASK (0x7 << 4)
-#define FIFO_FORMAT_32LSB (0x03 << 4)
-/* Other formats not yet known */
+#define FIFO_FORMAT_MASK    (0x7 << 4)
+#define FIFO_FORMAT_0       (0x0 << 4)
+/* Big-endian formats - data sent to the FIFO must be big endian.
+ * I forgot which is which size but did test them. */
+#define FIFO_FORMAT_1       (0x1 << 4)
+#define FIFO_FORMAT_2       (0x2 << 4)
+ /* 32bit-MSB-little endian */
+#define FIFO_FORMAT_LE32 (0x3 << 4)
+ /* 16bit-MSB-little endian */
+#define FIFO_FORMAT_LE16 (0x4 << 4)
+
+/* FIFO formats 0x5 and above seem equivalent to 0x4 ?? */
+
+/**
+ * PP502x
+ *
+ * IISCONFIG bits:
+ * |   31   |   30   |   29   |   28   |   27   |   26   |   25   |   24   |
+ * | RESET  |        |TXFIFOEN|RXFIFOEN|        |  ????  |   MS   |  ????  |
+ * |   23   |   22   |   21   |   20   |   19   |   18   |   17   |   16   |
+ * |        |        |        |        |        |        |        |        |
+ * |   15   |   14   |   13   |   12   |   11   |   10   |    9   |    8   |
+ * |        |        |        |        | Bus Format[1:0] |     Size[1:0]   |
+ * |    7   |    6   |    5   |    4   |    3   |    2   |    1   |    0   |
+ * |        |     Size Format[2:0]     |  ????  |  ????  | IRQTX  | IRQRX  |
+ *
+ * IISFIFO_CFG bits:
+ * |   31   |   30   |   29   |   28   |   27   |   26   |   25   |   24   |
+ * |        |                         Free[6:0]                            |
+ * |   23   |   22   |   21   |   20   |   19   |   18   |   17   |   16   |
+ * |        |        |        |        |        |        |        |        |
+ * |   15   |   14   |   13   |   12   |   11   |   10   |    9   |    8   |
+ * |        |        |        | RXCLR  |        |        |        | TXCLR  |
+ * |    7   |    6   |    5   |    4   |    3   |    2   |    1   |    0   |
+ * |        |        |   RX_ATN_LEVEL  |        |        |   TX_ATN_LEVEL  |
+ */
 
 /* Are we I2S Master or slave? */
 #define I2S_MASTER (1<<25)
@@ -83,12 +121,16 @@ void i2s_reset(void)
 
     /* FIFO.FORMAT */
     /* If BIT.SIZE < FIFO.FORMAT low bits will be 0 */
-    IISCONFIG = ((IISCONFIG & ~FIFO_FORMAT_MASK) | FIFO_FORMAT_32LSB);
 #ifdef HAVE_AS3514
     /* AS3514 can only operate as I2S Slave */
     IISCONFIG |= I2S_MASTER;
     /* Set I2S to 44.1kHz */
-    outl((inl(0x70002808) & ~(0x1ff)) | 271, 0x70002808);
+    outl((inl(0x70002808) & ~(0x1ff)) | 33, 0x70002808);
+    outl(7, 0x60006080);
+
+    IISCONFIG = ((IISCONFIG & ~FIFO_FORMAT_MASK) | FIFO_FORMAT_LE16);
+#else
+    IISCONFIG = ((IISCONFIG & ~FIFO_FORMAT_MASK) | FIFO_FORMAT_LE32);
 #endif
 
     /* RX_ATN_LVL=1 == when 12 slots full */
diff --git a/firmware/target/arm/pcm-pp.c b/firmware/target/arm/pcm-pp.c
index e483700e88..41bd92bd0d 100644
--- a/firmware/target/arm/pcm-pp.c
+++ b/firmware/target/arm/pcm-pp.c
@@ -93,13 +93,7 @@ void fiq(void)
         "bls .fifo_full       \n\t" /* FIFO full, exit */
         "ldr r10, [r9], #4    \n\t" /* load two samples */
 #ifdef HAVE_AS3514
-        /* The AS3514 reads 3 bytes at a time, it seems, ignoring the lowest.
-        This code seems to work well, but we may have to mask off the extra
-        bits - at the expense of a few extra cycles in the FIQ */
-        "mov r10, r10, ror #2\n\t" /* put left sample at the top bits */
-        "str r10, [r12, #0x40]\n\t" /* write top sample, lower sample ignored */
-        "mov r10, r10, ror #16\n\t" /* put left sample at the top bits */
-        "str r10, [r12, #0x40]\n\t" /* then write it */
+        "str r10, [r12, #0x40]\n\t" /* write them */
 #else
         "mov r10, r10, ror #16\n\t" /* put left sample at the top bits */
         "str r10, [r12, #0x40]\n\t" /* write top sample, lower sample ignored */
@@ -184,8 +178,13 @@ void fiq(void)
                 return;
             }
 
+#ifdef HAVE_AS3514
+            IISFIFO_WR = *(int32_t *)p;
+            p += 2;
+#else
             IISFIFO_WR = (*(p++))<<16;
             IISFIFO_WR = (*(p++))<<16;
+#endif
             p_size-=4;
         }
 
@@ -240,8 +239,13 @@ void pcm_play_dma_start(const void *addr, size_t size)
             return;
         }
 
+#ifdef HAVE_AS3514
+        IISFIFO_WR = *(int32_t *)p;
+        p += 2;
+#else
         IISFIFO_WR = (*(p++))<<16;
         IISFIFO_WR = (*(p++))<<16;
+#endif
         p_size-=4;
     }
 }
@@ -315,8 +319,13 @@ void pcm_play_pause_unpause(void)
             return;
         }
 
+#ifdef HAVE_AS3514
+        IISFIFO_WR = *(int32_t *)p;
+        p += 2;
+#else
         IISFIFO_WR = (*(p++))<<16;
         IISFIFO_WR = (*(p++))<<16;
+#endif
         p_size-=4;
     }
 }