1 files changed, 346 insertions, 0 deletions
diff --git a/nuttx/drivers/mtd/rammtd.c b/nuttx/drivers/mtd/rammtd.c
new file mode 100644
index 000000000..707192d88
--- /dev/null
+++ b/nuttx/drivers/mtd/rammtd.c
@@ -0,0 +1,346 @@
+/****************************************************************************
+ * drivers/mtd/rammtd.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <nuttx/ioctl.h>
+#include <nuttx/mtd.h>
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* Configuration ************************************************************/
+
+#ifndef CONFIG_RAMMTD_BLOCKSIZE
+#  define CONFIG_RAMMTD_BLOCKSIZE 512
+#endif
+
+#ifndef CONFIG_RAMMTD_ERASESIZE
+#  define CONFIG_RAMMTD_ERASESIZE 4096
+#endif
+
+#ifndef CONFIG_RAMMTD_ERASESTATE
+#  define CONFIG_RAMMTD_ERASESTATE 0xff
+#endif
+
+#if CONFIG_RAMMTD_BLOCKSIZE > CONFIG_RAMMTD_ERASESIZE
+#  error "Must have CONFIG_RAMMTD_BLOCKSIZE <= CONFIG_RAMMTD_ERASESIZE"
+#endif
+
+#undef  CONFIG_RAMMTD_BLKPER
+#define CONFIG_RAMMTD_BLKPER (CONFIG_RAMMTD_ERASESIZE/CONFIG_RAMMTD_BLOCKSIZE)
+
+#if CONFIG_RAMMTD_BLKPER*CONFIG_RAMMTD_BLOCKSIZE != CONFIG_RAMMTD_ERASESIZE
+#  error "CONFIG_RAMMTD_ERASESIZE must be an even multiple of CONFIG_RAMMTD_BLOCKSIZE"
+#endif
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+/* This type represents the state of the MTD device.  The struct mtd_dev_s
+ * must appear at the beginning of the definition so that you can freely
+ * cast between pointers to struct mtd_dev_s and struct ram_dev_s.
+ */
+
+struct ram_dev_s
+{
+  struct mtd_dev_s mtd;      /* MTD device */
+  FAR uint8_t     *start;    /* Start of RAM */
+  size_t           nblocks;  /* Number of erase blocks */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+/* MTD driver methods */
+
+static int ram_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks);
+static ssize_t ram_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                          FAR uint8_t *buf);
+static ssize_t ram_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                           FAR const uint8_t *buf);
+static int ram_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ram_erase
+ ****************************************************************************/
+
+static int ram_erase(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks)
+{
+  FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev;
+  off_t offset;
+  size_t nbytes;
+
+  DEBUGASSERT(dev);
+
+  /* Convert the erase block to a logical block and the number of blocks
+   * in logical block numbers
+   */
+
+  startblock *= CONFIG_RAMMTD_BLKPER;
+  nblocks    *= CONFIG_RAMMTD_BLKPER;
+
+  /* Don't let the erase exceed the size of the ram buffer */
+
+  if (startblock >= priv->nblocks)
+    {
+      return 0;
+    }
+
+  if (startblock + nblocks >= priv->nblocks)
+    {
+      nblocks = priv->nblocks - nblocks;
+    }
+
+  /* Get the offset corresponding to the first block and the size
+   * corresponding to the number of blocks.
+   */
+
+  offset = startblock * CONFIG_RAMMTD_BLOCKSIZE;
+  nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE;
+
+  /* Then erase the data in RAM */
+
+  memset(&priv->start[offset], CONFIG_RAMMTD_ERASESTATE, nbytes);
+  return OK;
+}
+
+/****************************************************************************
+ * Name: ram_bread
+ ****************************************************************************/
+
+static ssize_t ram_bread(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                          FAR uint8_t *buf)
+{
+  FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev;
+  off_t offset;
+  size_t nbytes;
+
+  DEBUGASSERT(dev && buf);
+
+  /* Don't let the read exceed the size of the ram buffer */
+
+  if (startblock >= priv->nblocks)
+    {
+      return 0;
+    }
+
+  if (startblock + nblocks >= priv->nblocks)
+    {
+      nblocks = priv->nblocks - nblocks;
+    }
+
+  /* Get the offset corresponding to the first block and the size
+   * corresponding to the number of blocks.
+   */
+
+  offset = startblock * CONFIG_RAMMTD_BLOCKSIZE;
+  nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE;
+
+  /* Then read the data frp, RAM */
+
+  memcpy(buf, &priv->start[offset], nbytes);
+  return nblocks;
+}
+
+/****************************************************************************
+ * Name: ram_bwrite
+ ****************************************************************************/
+
+static ssize_t ram_bwrite(FAR struct mtd_dev_s *dev, off_t startblock, size_t nblocks,
+                           FAR const uint8_t *buf)
+{
+  FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev;
+  off_t offset;
+  size_t nbytes;
+
+  DEBUGASSERT(dev && buf);
+
+  /* Don't let the write exceed the size of the ram buffer */
+
+  if (startblock >= priv->nblocks)
+    {
+      return 0;
+    }
+
+  if (startblock + nblocks >= priv->nblocks)
+    {
+      nblocks = priv->nblocks - nblocks;
+    }
+
+  /* Get the offset corresponding to the first block and the size
+   * corresponding to the number of blocks.
+   */
+
+  offset = startblock * CONFIG_RAMMTD_BLOCKSIZE;
+  nbytes = nblocks * CONFIG_RAMMTD_BLOCKSIZE;
+
+  /* Then write the data to RAM */
+
+  memcpy(&priv->start[offset], buf, nbytes);
+  return nblocks;
+}
+
+/****************************************************************************
+ * Name: ram_ioctl
+ ****************************************************************************/
+
+static int ram_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
+{
+  FAR struct ram_dev_s *priv = (FAR struct ram_dev_s *)dev;
+  int ret = -EINVAL; /* Assume good command with bad parameters */
+
+  switch (cmd)
+    {
+      case MTDIOC_GEOMETRY:
+        {
+          FAR struct mtd_geometry_s *geo = (FAR struct mtd_geometry_s *)arg;
+          if (geo)
+            {
+              /* Populate the geometry structure with information need to know
+               * the capacity and how to access the device.
+               */
+
+              geo->blocksize    = CONFIG_RAMMTD_BLOCKSIZE;
+              geo->erasesize    = CONFIG_RAMMTD_ERASESIZE;
+              geo->neraseblocks = priv->nblocks;
+              ret               = OK;
+          }
+        }
+        break;
+
+      case MTDIOC_XIPBASE:
+        {
+          FAR void **ppv = (FAR void**)arg;
+          if (ppv)
+            {
+              /* Return (void*) base address of device memory */
+
+              *ppv = (FAR void*)priv->start;
+              ret  = OK;
+            }
+        }
+        break;
+
+      case MTDIOC_BULKERASE:
+        {
+            size_t size = priv->nblocks * CONFIG_RAMMTD_ERASESIZE;
+
+	        /* Erase the entire device */
+
+            memset(priv->start, CONFIG_RAMMTD_ERASESTATE, size);
+	        ret = OK;
+        }
+        break;
+ 
+      default:
+        ret = -ENOTTY; /* Bad command */
+        break;
+    }
+
+  return ret;
+}
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: rammtd_initialize
+ *
+ * Description:
+ *   Create and initialize a RAM MTD device instance.
+ *
+ * Input Parameters:
+ *   start - Address of the beginning of the allocated RAM regions.
+ *   size  - The size in bytes of the allocated RAM region.
+ *
+ ****************************************************************************/
+
+FAR struct mtd_dev_s *rammtd_initialize(FAR uint8_t *start, size_t size)
+{
+  FAR struct ram_dev_s *priv;
+  size_t nblocks;
+
+  /* Create an instance of the RAM MTD device state structure */
+
+  priv = (FAR struct ram_dev_s *)kzmalloc(sizeof(struct ram_dev_s));
+  if (!priv)
+    {
+      fdbg("Failed to allocate the RAM MTD state structure\n");
+      return NULL;
+    }
+
+  /* Force the size to be an even number of the erase block size */
+
+  nblocks = size / CONFIG_RAMMTD_ERASESIZE;
+  if (nblocks <= 0)
+    {
+      fdbg("Need to provide at least one full erase block\n");
+      return NULL;
+    }
+  
+  /* Perform initialization as necessary */
+
+  priv->mtd.erase  = ram_erase;
+  priv->mtd.bread  = ram_bread;
+  priv->mtd.bwrite = ram_bwrite;
+  priv->mtd.ioctl  = ram_ioctl;
+  priv->mtd.erase  = ram_erase;
+
+  priv->start      = start;
+  priv->nblocks    = nblocks;
+  return &priv->mtd;
+}