From 5312f45737db0ee11609b3fa5156742ded554c0a Mon Sep 17 00:00:00 2001
From: Clint Stevenson <clintastevenson@gmail.com>
Date: Mon, 12 Jun 2017 22:21:05 -0500
Subject: [PATCH] Added private variable 'chipID'. Made corrections to command
 byte in readSerialNumber method and generally improved to work with multiple
 chips that support this feature. Added method readSFDP used to support
 readSerialNumber.

---
 SerialFlash.h       |  2 ++
 SerialFlashChip.cpp | 42 +++++++++++++++++++++++++++++++++++++-----
 2 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/SerialFlash.h b/SerialFlash.h
index 3c0a5ae..fb8f292 100644
--- a/SerialFlash.h
+++ b/SerialFlash.h
@@ -44,6 +44,7 @@ class SerialFlashChip
 	static void wakeup();
 	static void readID(uint8_t *buf);
 	static void readSerialNumber(uint8_t *buf);
+	static void readSFDP(uint8_t* buf, uint8_t addr, uint16_t len);
 	static void read(uint32_t addr, void *buf, uint32_t len);
 	static bool ready();
 	static void wait();
@@ -68,6 +69,7 @@ class SerialFlashChip
 				// 1 = suspendable program operation
 				// 2 = suspendable erase operation
 				// 3 = busy for realz!!
+	static uint8_t chipID;
 };
 
 extern SerialFlashChip SerialFlash;
diff --git a/SerialFlashChip.cpp b/SerialFlashChip.cpp
index 7af00d2..f60585c 100644
--- a/SerialFlashChip.cpp
+++ b/SerialFlashChip.cpp
@@ -35,6 +35,7 @@
 uint16_t SerialFlashChip::dirindex = 0;
 uint8_t SerialFlashChip::flags = 0;
 uint8_t SerialFlashChip::busy = 0;
+uint8_t SerialFlashChip::chipID = 0;
 
 static volatile IO_REG_TYPE *cspin_basereg;
 static IO_REG_TYPE cspin_bitmask;
@@ -426,6 +427,7 @@ void SerialFlashChip::readID(uint8_t *buf)
 	}
 	CSRELEASE();
 	SPIPORT.endTransaction();
+	chipID = buf[0];			// Save ID for retrieval later
 	//Serial.printf("ID: %02X %02X %02X\n", buf[0], buf[1], buf[2]);
 }
 
@@ -434,17 +436,46 @@ void SerialFlashChip::readSerialNumber(uint8_t *buf) //needs room for 8 bytes
 	if (busy) wait();
 	SPIPORT.beginTransaction(SPICONFIG);
 	CSASSERT();
-	SPIPORT.transfer(0x4B);			
-	SPIPORT.transfer16(0);	
-	SPIPORT.transfer16(0);
-	for (int i=0; i<8; i++) {		
-		buf[i] = SPIPORT.transfer(0);
+	if (ID0_SPANSION == chipID) {
+		// Spansion UniqueID is stored in the SFDP region at address 0x5A
+		// Spansion does not support the 0x4B UniqueID command
+		readSFDP(buf, 0xF8, 8);
+	}
+	else {
+		if (ID0_SST == chipID) {
+			SPIPORT.transfer(0x88);		// SST is 0x88
+			SPIPORT.transfer16(0);		// Dummy bits 15:0
+		}
+		else if (ID0_WINBOND == chipID) {
+			SPIPORT.transfer(0x4B);		// Winbond is 0x4B
+			SPIPORT.transfer16(0);		// Dummy bits 31:16
+			SPIPORT.transfer16(0);		// Dummy bits 15:0
+		}
+		for (int i=0; i<8; i++) {		
+			buf[i] = SPIPORT.transfer(0);
+		}
 	}
 	CSRELEASE();
 	SPIPORT.endTransaction();
 //	Serial.printf("Serial Number: %02X %02X %02X %02X %02X %02X %02X %02X\n", buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
 }
 
+void SerialFlashChip::readSFDP(uint8_t* buf, uint8_t addr, uint16_t len) // buf needs room for up to 256 bytes for entire SFDP
+{
+	if (busy) wait();
+	SPIPORT.beginTransaction(SPICONFIG);
+	CSASSERT();
+	SPIPORT.transfer(0x5A);				// Read SFDP command
+	SPIPORT.transfer16(0);				// Dummy bits 31:16
+	SPIPORT.transfer(addr);				// SFDP address byte
+	SPIPORT.transfer(0);				// Dummy bits 7:0
+	for (int i = 0; i < len; i++) {
+		buf[i] = SPIPORT.transfer(0);
+	}
+	CSRELEASE();
+	SPIPORT.endTransaction();
+}
+
 uint32_t SerialFlashChip::capacity(const uint8_t *id)
 {
 	uint32_t n = 1048576; // unknown chips, default to 1 MByte
@@ -500,6 +531,7 @@ SST26VF032	4
 // Spansion S25FL128P	16	64	01 20 18
 // Spansion S25FL256S	32	64	01 02 19	05			60 & C7
 // Spansion S25FL512S	64	256	01 02 20
+// Spansion S25FL116	2	4	01 40 15
 // Macronix MX25L12805D 16	?	C2 20 18
 // Macronix MX66L51235F	64		C2 20 1A
 // Numonyx M25P128	16	?	20 20 18