Added full chip erase function to W25Qx driver

platform/drivers/NVM/W25Qx.c

@@ -34,6 +34,7 @@
 #define CMD_RSECR 0x48   /* Read security register */
 #define CMD_WKUP  0xAB   /* Release power down     */
 #define CMD_PDWN  0xB9   /* Power down             */
+#define CMD_ECHIP 0xC7   /* Full chip erase        */
 
 /*
  * Target-specific SPI interface functions, their implementation can be found
@@ -159,6 +160,41 @@ bool W25Qx_eraseSector(uint32_t addr)
     return false;
 }
 
+bool W25Qx_eraseChip()
+{
+    gpio_clearPin(FLASH_CS);
+    (void) spiFlash_SendRecv(CMD_WREN);     /* Write enable */
+    gpio_setPin(FLASH_CS);
+
+    delayUs(5);
+
+    gpio_clearPin(FLASH_CS);
+    (void) spiFlash_SendRecv(CMD_ECHIP);    /* Command */
+    gpio_setPin(FLASH_CS);
+
+    /*
+     * Wait till erase terminates.
+     * Timeout after 200s, at 20ms per tick
+     */
+    uint16_t timeout = 10000;
+    while(timeout > 0)
+    {
+        delayMs(20);
+        timeout--;
+
+        gpio_clearPin(FLASH_CS);
+        (void) spiFlash_SendRecv(CMD_RDSTA);        /* Read status    */
+        uint8_t status = spiFlash_SendRecv(0x00);
+        gpio_setPin(FLASH_CS);
+
+        /* If busy flag is low, we're done */
+        if((status & 0x01) == 0) return true;
+    }
+
+    /* If we get here, we had a timeout */
+    return false;
+}
+
 ssize_t W25Qx_writePage(uint32_t addr, void* buf, size_t len)
 {
     /* Keep 256-byte boundary to avoid wrap-around when writing */

platform/drivers/NVM/W25Qx.h

@@ -86,6 +86,14 @@ void W25Qx_readData(uint32_t addr, void *buf, size_t len);
  */
 bool W25Qx_eraseSector(uint32_t addr);
 
+/**
+ * Full chip erase.
+ * Function returns when erase process terminated.
+ *
+ * @return true on success, false on failure.
+ */
+bool W25Qx_eraseChip();
+
 /**
  * Write data to a 256-byte flash memory page.
  * NOTE: if data size goes beyond the 256 byte boundary, length will be truncated