DataFlash: fallback to BlockErase if ChipErase fails

The errata on the APM2 dataflash chip says that ChipErase may not work
on some chips

libraries/DataFlash/DataFlash.cpp

@@ -3,6 +3,7 @@
 	DataFlash.cpp - DataFlash log library generic code
 */
 
+#include <FastSerial.h>
 #include <stdint.h>
 #include "DataFlash.h"
 
@@ -188,8 +189,28 @@ uint16_t DataFlash_Class::GetFilePage()
 
 void DataFlash_Class::EraseAll(void (*delay_cb)(unsigned long))
 {
+    // write a bad value to the last page
+    StartWrite(df_NumPages+1);
+    WriteLong(DF_LOGGING_FORMAT_INVALID);
+	BufferToPage(df_BufferNum,df_PageAdr,1);
+
     ChipErase(delay_cb);
 	SetFileNumber(0xFFFF);
+
+    StartRead(0);
+    StartRead(df_NumPages+1);
+    int32_t format = ReadLong();
+
+    if (format == DF_LOGGING_FORMAT_INVALID) {
+        // the chip erase didn't work - fall back to a erasing
+        // each page separately. The errata on the APM2 dataflash chip
+        // suggests that chip erase won't always work
+        for(uint16_t j = 1; j <= (df_NumPages+1)/8; j++) {
+            BlockErase(j);
+            delay_cb(1);
+        }
+    }
+
     // write the logging format in the last page
     StartWrite(df_NumPages+1);
     WriteLong(DF_LOGGING_FORMAT);

libraries/DataFlash/DataFlash.h

@@ -12,6 +12,9 @@
 // this if (and only if!) the low level format changes
 #define DF_LOGGING_FORMAT    0x28122011
 
+// we use an invalie logging format to test the chip erase
+#define DF_LOGGING_FORMAT_INVALID   0x28122012
+
 class DataFlash_Class
 {
   private:
@@ -32,6 +35,7 @@ class DataFlash_Class
 	virtual void PageToBuffer(unsigned char BufferNum, uint16_t PageAdr) = 0;
 	virtual unsigned char BufferRead (unsigned char BufferNum, uint16_t IntPageAdr) = 0;
 	virtual void PageErase(uint16_t PageAdr) = 0;
+	virtual void BlockErase(uint16_t BlockAdr) = 0;
 	virtual void ChipErase(void (*delay_cb)(unsigned long)) = 0;
 
 	// internal high level functions

libraries/DataFlash/DataFlash_APM1.cpp

@@ -294,6 +294,29 @@ void DataFlash_APM1::PageErase (uint16_t PageAdr)
 }
 
 
+void DataFlash_APM1::BlockErase (uint16_t BlockAdr)
+{
+  dataflash_CS_active();     // activate dataflash command decoder
+  SPI.transfer(DF_BLOCK_ERASE);   // Command
+
+  if (df_PageSize==512) {
+      SPI.transfer((unsigned char)(BlockAdr >> 3));
+      SPI.transfer((unsigned char)(BlockAdr << 5));
+  } else {
+      SPI.transfer((unsigned char)(BlockAdr >> 4));
+      SPI.transfer((unsigned char)(BlockAdr << 4));
+  }
+
+  SPI.transfer(0x00);	           // "dont cares"
+  dataflash_CS_inactive();               //initiate flash page erase
+  dataflash_CS_active();
+  while(!ReadStatus());
+
+  dataflash_CS_inactive();   // deactivate dataflash command decoder
+}
+
+
+
 void DataFlash_APM1::ChipErase(void (*delay_cb)(unsigned long))
 {
 

libraries/DataFlash/DataFlash_APM1.h

@@ -19,6 +19,7 @@ class DataFlash_APM1 : public DataFlash_Class
 	unsigned char ReadStatus();
 	uint16_t PageSize();
 	void PageErase (uint16_t PageAdr);
+	void BlockErase (uint16_t BlockAdr);
 	void ChipErase(void (*delay_cb)(unsigned long));
 
   public:

libraries/DataFlash/DataFlash_APM2.cpp

@@ -349,6 +349,33 @@ void DataFlash_APM2::PageErase (uint16_t PageAdr)
 	CS_inactive();
 }
 
+// erase a block of 8 pages.
+void DataFlash_APM2::BlockErase(uint16_t BlockAdr)
+{
+	// activate dataflash command decoder
+	CS_active();
+
+	// Send block erase command
+	SPI_transfer(DF_BLOCK_ERASE);
+
+	if (df_PageSize==512) {
+		SPI_transfer((unsigned char)(BlockAdr >> 3));
+		SPI_transfer((unsigned char)(BlockAdr << 5));
+	} else {
+		SPI_transfer((unsigned char)(BlockAdr >> 4));
+		SPI_transfer((unsigned char)(BlockAdr << 4));
+	}
+	SPI_transfer(0x00);
+
+	//initiate flash page erase
+	CS_inactive();
+	CS_active();
+	while(!ReadStatus());
+
+	// release SPI bus for use by other sensors
+	CS_inactive();
+}
+
 
 void DataFlash_APM2::ChipErase(void (*delay_cb)(unsigned long))
 {

libraries/DataFlash/DataFlash_APM2.h

@@ -23,6 +23,7 @@ class DataFlash_APM2 : public DataFlash_Class
 	void CS_inactive();
 	void CS_active();
 	void PageErase (uint16_t PageAdr);
+	void BlockErase (uint16_t BlockAdr);
 	void ChipErase(void (*delay_cb)(unsigned long));
 
   public: