progmem interface: Discern r/w and erase page sizes. Introduce new up_progmem_erasesize architecture API to be able to communicate the read/write page size independently from erase page size. Implement up_progmem_erasesize for all architectures that already support progmem, assuming that for those architectures the sizes of both read/write and erase pages are identical.

arch/arm/src/efm32/efm32_flash.c

@@ -577,6 +577,11 @@ size_t up_progmem_pagesize(size_t page)
   return 0;
 }
 
+size_t up_progmem_erasesize(size_t page)
+{
+  return up_progmem_pagesize(page);
+}
+
 ssize_t up_progmem_getpage(size_t addr)
 {
 #if (EFM32_FLASH_BASE != 0)

arch/arm/src/samv7/sam_progmem.c

@@ -409,6 +409,19 @@ size_t up_progmem_pagesize(size_t cluster)
   return SAMV7_CLUSTER_SIZE;
 }
 
+/****************************************************************************
+ * Name: up_progmem_erasesize
+ *
+ * Description:
+ *   Return cluster size
+ *
+ ****************************************************************************/
+
+size_t up_progmem_erasesize(size_t cluster)
+{
+  return SAMV7_CLUSTER_SIZE;
+}
+
 /****************************************************************************
  * Name: up_progmem_getpage
  *

arch/arm/src/stm32/stm32_flash.c

@@ -512,6 +512,11 @@ size_t up_progmem_pagesize(size_t page)
   return STM32_FLASH_PAGESIZE;
 }
 
+size_t up_progmem_erasesize(size_t page)
+{
+  return STM32_FLASH_PAGESIZE;
+}
+
 ssize_t up_progmem_getpage(size_t addr)
 {
   if (addr >= STM32_FLASH_BASE)

arch/arm/src/stm32l4/stm32l4_flash.c

@@ -276,6 +276,11 @@ size_t up_progmem_pagesize(size_t page)
   return STM32L4_FLASH_PAGESIZE;
 }
 
+size_t up_progmem_erasesize(size_t page)
+{
+  return STM32L4_FLASH_PAGESIZE;
+}
+
 ssize_t up_progmem_getpage(size_t addr)
 {
   if (addr >= STM32L4_FLASH_BASE)

drivers/mtd/mtd_progmem.c

@@ -69,7 +69,8 @@ struct progmem_dev_s
   /* Fields unique to the progmem MTD driver */
 
   bool    initialized;      /* True: Already initialized */
-  uint8_t blkshift;         /* Log2 of the flash block size */
+  uint8_t blkshift;         /* Log2 of the flash read/write block size */
+  uint8_t ersshift;         /* Log2 of the flash erase block size */
 };
 
 /****************************************************************************
@@ -314,7 +315,7 @@ static int progmem_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
                */
 
               geo->blocksize    = (1 << priv->blkshift);  /* Size of one read/write block */
-              geo->erasesize    = (1 << priv->blkshift);  /* Size of one erase block */
+              geo->erasesize    = (1 << priv->ersshift);  /* Size of one erase block */
               geo->neraseblocks = up_progmem_npages();    /* Number of erase blocks */
               ret               = OK;
           }
@@ -374,6 +375,7 @@ FAR struct mtd_dev_s *progmem_initialize(void)
 {
   FAR struct progmem_dev_s *priv = (FAR struct progmem_dev_s *)&g_progmem;
   int32_t blkshift;
+  int32_t ersshift;
 
   /* Perform initialization if necessary */
 
@@ -386,7 +388,7 @@ FAR struct mtd_dev_s *progmem_initialize(void)
 
       size_t blocksize = up_progmem_pagesize(0);
 
-     /* Calculate Log2 of the flash block size */
+      /* Calculate Log2 of the flash read/write block size */
 
       blkshift = progmem_log2(blocksize);
       if (blkshift < 0)
@@ -394,9 +396,20 @@ FAR struct mtd_dev_s *progmem_initialize(void)
           return NULL;
         }
 
+      /* Calculate Log2 of the flash erase block size */
+
+      blocksize = up_progmem_erasesize(0);
+
+      ersshift = progmem_log2(blocksize);
+      if (ersshift < 0)
+        {
+          return NULL;
+        }
+
       /* Save the configuration data */
 
       g_progmem.blkshift    = blkshift;
+      g_progmem.ersshift    = ersshift;
       g_progmem.initialized = true;
 
 #ifdef CONFIG_MTD_REGISTRATION

include/nuttx/progmem.h

@@ -68,7 +68,7 @@ extern "C"
  * Name: up_progmem_npages
  *
  * Description:
- *   Return number of pages
+ *   Return number of erase pages
  *
  ****************************************************************************/
 
@@ -78,7 +78,7 @@ size_t up_progmem_npages(void);
  * Name: up_progmem_isuniform
  *
  * Description:
- *   Is program memory uniform or page size differs?
+ *   Is program memory uniform or erase page and read/write page size differs?
  *
  ****************************************************************************/
 
@@ -88,17 +88,27 @@ bool up_progmem_isuniform(void);
  * Name: up_progmem_pagesize
  *
  * Description:
- *   Return page size
+ *   Return read/write page size
  *
  ****************************************************************************/
 
 size_t up_progmem_pagesize(size_t page);
 
+/****************************************************************************
+ * Name: up_progmem_erasesize
+ *
+ * Description:
+ *   Return erase page size. Must be a multiple of the read/write page size.
+ *
+ ****************************************************************************/
+
+size_t up_progmem_erasesize(size_t page);
+
 /****************************************************************************
  * Name: up_progmem_getpage
  *
  * Description:
- *   Address to page conversion
+ *   Address to read/write page conversion
  *
  * Input Parameters:
  *   addr - Address with or without flash offset (absolute or aligned to page0)
@@ -117,7 +127,7 @@ ssize_t up_progmem_getpage(size_t addr);
  * Name: up_progmem_getaddress
  *
  * Description:
- *   Page to address conversion
+ *   Read/write page to address conversion
  *
  * Input Parameters:
  *   page - page index
@@ -133,10 +143,10 @@ size_t up_progmem_getaddress(size_t page);
  * Name: up_progmem_erasepage
  *
  * Description:
- *   Erase selected page.
+ *   Erase selected erase page.
  *
  * Input Parameters:
- *   page - The page index to be erased.
+ *   page - The erase page index to be erased.
  *
  * Returned Value:
  *   Page size or negative value on error.  The following errors are reported
@@ -157,7 +167,7 @@ ssize_t up_progmem_erasepage(size_t page);
  * Name: up_progmem_ispageerased
  *
  * Description:
- *   Checks whether page is erased
+ *   Checks whether erase page is erased
  *
  * Input Parameters:
  *   page - The page index to be checked.