Changeset 398

Timestamp:

May 30, 2013, 5:16:33 PM (12 years ago)

Author:

bouyer

Message:

Use 128bits transfers at the SPI controller level when possible;
this speeds up the boot

Location:

trunk/softs/tsar_boot

Files:

• include/spi.h (modified) (1 diff)
• src/sdcard.c (modified) (2 diffs)
• src/spi.c (modified) (2 diffs)

trunk/softs/tsar_boot/include/spi.h

@@ -60 +60 @@
  */
 inline volatile unsigned char spi_get_rx(struct spi_dev * spi, int index);
+
+/**
+ * \param   spi     : initialized pointer to a SPI controller.
+ * \param   buf     : buffer to store data read
+ * \param   count   : byte count to read
+ *
+ * \return  void
+ *
+ * \brief   get a data block from the SPI controller using 128bits
+ *          reads if possible
+ */
+void spi_get_data(struct spi_dev * spi, void *buf, unsigned int count);
 
 /**

trunk/softs/tsar_boot/src/sdcard.c

@@ -228 +228 @@
     _sdcard_wait_data_block(sdcard);
 
-    for ( i = 0; i < count; i++ )
-    {
-        *((char *) buf + i) = _sdcard_receive_char(sdcard);
-    }
+    spi_get_data(sdcard->spi, buf, count);
 
     /*
@@ -237 +234 @@
      * at the end of the data block)
      */
+    i = count;
     while( i++ < (sdcard->block_length + 2) ) _sdcard_receive_char(sdcard);
 

trunk/softs/tsar_boot/src/spi.c

@@ -5 +5 @@
  */
 #include <spi.h>
+
+/**
+ * \param   x: input value
+ *
+ * \return  byte-swapped value
+ *
+ * \brief   byte-swap a 32bit word
+ */
+static unsigned int bswap32(unsigned int x)
+{
+  unsigned int y;
+  y =  (x & 0x000000ff) << 24;
+  y |= (x & 0x0000ff00) <<  8;
+  y |= (x & 0x00ff0000) >>  8;
+  y |= (x & 0xff000000) >> 24;
+  return y;
+}
 
 /**
@@ -67 +84 @@
 }
 
+void spi_get_data(struct spi_dev * spi, void *buf, unsigned int count)
+{
+    unsigned int *data = buf;
+    unsigned char *data8;
+    unsigned int spi_ctrl0, spi_ctrl;
+    int i;
+
+    _spi_wait_if_busy(spi);
+    /* switch to 128 bits words */
+    spi_ctrl0 = ioread32(&spi->ctrl);
+    spi_ctrl = (spi_ctrl0 & ~SPI_CTRL_CHAR_LEN_MASK) | 128;
+    iowrite32(&spi->ctrl, spi_ctrl);
+
+    /* read data */
+    for (i = 0; i + 3 < count / 4; i += 4) {
+        iowrite32(&spi->rx_tx[0], 0xffffffff);
+        iowrite32(&spi->rx_tx[1], 0xffffffff);
+        iowrite32(&spi->rx_tx[2], 0xffffffff);
+        iowrite32(&spi->rx_tx[3], 0xffffffff);
+        iowrite32(&spi->ctrl,  spi_ctrl | SPI_CTRL_GO_BSY);
+        _spi_wait_if_busy(spi);
+        *data = bswap32(ioread32(&spi->rx_tx[3]));
+        data++;
+        *data = bswap32(ioread32(&spi->rx_tx[2]));
+        data++;
+        *data = bswap32(ioread32(&spi->rx_tx[1]));
+        data++;
+        *data = bswap32(ioread32(&spi->rx_tx[0]));
+        data++;
+    }
+    /* switch back to original word size */
+    iowrite32(&spi->ctrl, spi_ctrl0);
+    /* read missing bits */
+    data8 = (void *)data;
+    i = i * 4;
+    for (; i < count; i++) {
+        iowrite32(&spi->rx_tx[0], 0xffffffff);
+        iowrite32(&spi->ctrl,  spi_ctrl0 | SPI_CTRL_GO_BSY);
+        _spi_wait_if_busy(spi);
+        *data8 = spi_get_rx(spi, 0);
+        data8++;
+    }
+    return;
+}
+
 void spi_ss_assert(struct spi_dev * spi, int index)
 {