arch/arm/src/tiva: Implemented Flash CONFIG_MTD_BYTE_WRITE for TM4c1294. Implemented the tiva_write function which will write an arbitrary number of bytes to flash (in multiple of 4).

arch/arm/src/tiva/tiva_flash.c

@@ -2,7 +2,7 @@
  * arch/arm/src/tiva/tiva_flash.c
  *
  *   Copyright (c) 2013 Max Holtzberg. All rights reserved.
- *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2013, 2018 Gregory Nutt. All rights reserved.
  *
  *   Authors: Max Holtzberg <mh@uvc.de>
  *            Gregory Nutt <gnutt@nuttx.org>
@@ -64,8 +64,8 @@
  ****************************************************************************/
 
 #define TIVA_VIRTUAL_NPAGES (TIVA_FLASH_NPAGES - CONFIG_TIVA_FLASH_STARTPAGE)
-#define TIVA_VIRTUAL_BASE   (TIVA_FLASH_BASE \
-                             + CONFIG_TIVA_FLASH_STARTPAGE * TIVA_FLASH_PAGESIZE)
+#define TIVA_VIRTUAL_OFFSET (CONFIG_TIVA_FLASH_STARTPAGE * TIVA_FLASH_PAGESIZE)
+#define TIVA_VIRTUAL_BASE   (TIVA_FLASH_BASE + TIVA_VIRTUAL_OFFSET)
 
 /****************************************************************************
  * Private Types
@@ -120,6 +120,7 @@ static struct tiva_dev_s g_lmdev =
 #endif
     tiva_ioctl
   },
+
   /* Initialization of any other implementation specific data goes here */
 };
 
@@ -138,12 +139,15 @@ static struct tiva_dev_s g_lmdev =
 static int tiva_erase(FAR struct mtd_dev_s *dev, off_t startblock,
                       size_t nblocks)
 {
-  int curpage;
+  off_t endblock;
   uint32_t pageaddr;
+  uint32_t regval;
+  int curpage;
 
-  DEBUGASSERT(nblocks <= TIVA_VIRTUAL_NPAGES);
+  endblock = startblock + nblocks;
+  DEBUGASSERT(endblock <= TIVA_VIRTUAL_NPAGES);
 
-  for (curpage = startblock; curpage < nblocks; curpage++)
+  for (curpage = startblock; curpage < endblock; curpage++)
     {
       pageaddr = TIVA_VIRTUAL_BASE + curpage * TIVA_FLASH_PAGESIZE;
 
@@ -160,7 +164,19 @@ static int tiva_erase(FAR struct mtd_dev_s *dev, off_t startblock,
 
       /* wait until erase has finished */
 
-      while (getreg32(TIVA_FLASH_FMC) & FLASH_FMC_ERASE);
+      while (getreg32(TIVA_FLASH_FMC) & FLASH_FMC_ERASE)
+        {
+        }
+
+      /* Return an error if an access violation or erase error occurred. */
+
+      regval  = getreg32(TIVA_FLASH_FCRIS);
+      regval &= (FLASH_FCRIS_ARIS | FLASH_FCRIS_VOLTRIS | FLASH_FCRIS_ERRIS);
+
+      if (regval != 0)
+        {
+           return -EACCES;
+        }
     }
 
   return OK;
@@ -255,7 +271,90 @@ static ssize_t tiva_read(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
 static ssize_t tiva_write(FAR struct mtd_dev_s *dev, off_t offset, size_t nbytes,
                           FAR const uint8_t *buf)
 {
-  return -ENOSYS;
+  FAR const uint32_t *src = (uint32_t *)((uintptr_t)buf & ~3);
+  ssize_t remaining;
+  uint32_t regval;
+
+  DEBUGASSERT(dev != NULL && buf != NULL);
+  DEBUGASSERT(((uintptr_t)buf & 3) == 0 && (offset & 3) == 0 && (nbytes && 3) == 0);
+
+  /* Clear the flash access and error interrupts. */
+
+   putreg32(FLASH_FCMISC_AMISC | FLASH_FCMISC_VOLTMISC | FLASH_FCMISC_ERMISC,
+            TIVA_FLASH_FCMISC);
+
+  /* Adjust the offset to the start of the partition.
+   * REVISIT:  If we really wanted to gracefully handler unaligned addresses,
+   * offsets, and sizes we would have to do a little more than this.
+   */
+
+  offset   &= ~3;
+  offset   += TIVA_VIRTUAL_OFFSET;
+  nbytes   &= ~3;
+  remaining = nbytes;
+
+#if defined(CONFIG_ARCH_CHIP_TM4C1294NC)
+  while (remaining > 0)
+    {
+      /* Set the address of this block of words. */
+
+      putreg32((offset & ~(0x7f)), TIVA_FLASH_FMA);
+
+      /* Loop over the words in this 32-word block. */
+
+      while(((offset & 0x7c) || (getreg32(TIVA_FLASH_FWBN) == 0)) &&
+            (remaining > 0))
+        {
+          /* Write this word into the write buffer. */
+
+          putreg32(*src++, (TIVA_FLASH_FWBN + (offset & 0x7c)));
+          offset    += 4;
+          remaining -= 4;
+        }
+
+      /* Program the contents of the write buffer into flash. */
+
+       putreg32(FLASH_FMC_WRKEY | FLASH_FMC2_WRBUF, TIVA_FLASH_FMC2);
+
+       /* Wait until the write buffer has been programmed. */
+
+       while(getreg32(TIVA_FLASH_FMC2) & FLASH_FMC2_WRBUF)
+         {
+         }
+     }
+#else
+  while (remaining > 0)
+    {
+      /* Program the next word. */
+
+       putreg32(offset, TIVA_FLASH_FMA);
+       putreg32(*src, TIVA_FLASH_FMD);
+       putreg32(FLASH_FMC_WRKEY | FLASH_FMC_WRITE, TIVA_FLASH_FMC);
+
+       /* Wait until the word has been programmed. */
+
+       while(getreg32(TIVA_FLASH_FMC) & FLASH_FMC_WRITE);
+
+       /* Increment to the next word. */
+
+       src++;
+       offset    += 4;
+       remaining -= 4;
+    }
+#endif
+
+  /* Return an error if an access violation or erase error occurred. */
+
+  regval  = getreg32(TIVA_FLASH_FCRIS);
+  regval &= (FLASH_FCRIS_ARIS | FLASH_FCRIS_VOLTRIS | FLASH_FCRIS_INVDRIS |
+             FLASH_FCRIS_PROGRIS);
+
+  if (regval != 0)
+    {
+       return -EACCES;
+    }
+
+  return nbytes;
 }
 #endif