Added QSPI with DMA support

Author: dgarske

config/examples/versal_vmk180.config

@@ -93,6 +93,17 @@ CFLAGS_EXTRA+=-DWOLFBOOT_SHA_BLOCK_SIZE=4096
 # UART Configuration - UART0 for APU console
 CFLAGS_EXTRA+=-DDEBUG_UART_NUM=0
 
-# QSPI flash debug and test options (uncomment to enable)
-#CFLAGS_EXTRA+=-DDEBUG_QSPI
-#CFLAGS_EXTRA+=-DTEST_EXT_FLASH
+# QSPI Reference Clock: Ref (300MHz default for Versal)
+#CFLAGS_EXTRA+=-DGQSPI_CLK_REF=300000000
+
+# QSPI Bus Divisor: (2 << div) = BUS (0=div2, 1=div4, 2=div8)
+# MT25QU01G max: 133MHz Quad Read (0x6C) with 8 dummy cycles
+# div=0: 300MHz/2 = 150MHz (above spec but tested working)
+# div=1: 300MHz/4 = 75MHz (within spec, default)
+# div=2: 300MHz/8 = 37.5MHz (conservative)
+#CFLAGS_EXTRA+=-DGQSPI_CLK_DIV=1
+
+# QSPI flash options (uncomment to enable)
+#CFLAGS_EXTRA+=-DDEBUG_QSPI       # Enable QSPI debug logging
+#CFLAGS_EXTRA+=-DGQSPI_MODE_IO    # Use polling instead of DMA (slower)
+#CFLAGS_EXTRA+=-DTEST_EXT_FLASH   # Run flash erase/write/read test