add support for setWritableCallback()

Author: hathach

examples/MassStorage/msc_external_flash/msc_external_flash.ino

@@ -146,7 +146,7 @@ void loop()
 // return number of copied bytes (must be multiple of block size) 
 int32_t msc_read_cb (uint32_t lba, void* buffer, uint32_t bufsize)
 {
-  // Note: SPIFLash Bock API: readBlocks/writeBlocks/syncBlocks
+  // Note: SPIFLash Block API: readBlocks/writeBlocks/syncBlocks
   // already include 4K sector caching internally. We don't need to cache it, yahhhh!!
   return flash.readBlocks(lba, (uint8_t*) buffer, bufsize/512) ? bufsize : -1;
 }
@@ -158,7 +158,7 @@ int32_t msc_write_cb (uint32_t lba, uint8_t* buffer, uint32_t bufsize)
 {
   digitalWrite(LED_BUILTIN, HIGH);
 
-  // Note: SPIFLash Bock API: readBlocks/writeBlocks/syncBlocks
+  // Note: SPIFLash Block API: readBlocks/writeBlocks/syncBlocks
   // already include 4K sector caching internally. We don't need to cache it, yahhhh!!
   return flash.writeBlocks(lba, buffer, bufsize/512) ? bufsize : -1;
 }

src/arduino/msc/Adafruit_USBD_MSC.cpp

@@ -112,6 +112,10 @@ void Adafruit_USBD_MSC::setReadyCallback(uint8_t lun, ready_callback_t cb) {
   _lun_info[lun].ready_cb = cb;
 }
 
+void Adafruit_USBD_MSC::setWritableCallback(uint8_t lun, writable_callback_t cb) {
+  _lun_info[lun].writable_cb = cb;
+}
+
 bool Adafruit_USBD_MSC::begin(void) {
   if (!TinyUSBDevice.addInterface(*this)) {
     return false;
@@ -256,6 +260,17 @@ void tud_msc_write10_complete_cb(uint8_t lun) {
   return _msc_dev->_lun_info[lun].fl_cb();
 }
 
+// Invoked to check if device is writable as part of SCSI WRITE10
+// Default mode is writable
+bool tud_msc_is_writable_cb(uint8_t lun)
+{
+  if (!(_msc_dev && _msc_dev->_lun_info[lun].writable_cb)) {
+    return true;
+  }
+
+  return _msc_dev->_lun_info[lun].writable_cb();
+}
+
 } // extern "C"
 
 #endif // TUSB_OPT_DEVICE_ENABLED

src/arduino/msc/Adafruit_USBD_MSC.h

@@ -35,6 +35,7 @@ class Adafruit_USBD_MSC : public Adafruit_USBD_Interface {
                                       uint32_t bufsize);
   typedef void (*flush_callback_t)(void);
   typedef bool (*ready_callback_t)(void);
+  typedef bool (*writable_callback_t)(void);
 
   Adafruit_USBD_MSC(void);
 
@@ -51,6 +52,7 @@ class Adafruit_USBD_MSC : public Adafruit_USBD_Interface {
   void setReadWriteCallback(uint8_t lun, read_callback_t rd_cb,
                             write_callback_t wr_cb, flush_callback_t fl_cb);
   void setReadyCallback(uint8_t lun, ready_callback_t cb);
+  void setWritableCallback(uint8_t lun, writable_callback_t cb);
 
   //------------- Single LUN API -------------//
   void setID(const char *vendor_id, const char *product_id,
@@ -70,18 +72,20 @@ class Adafruit_USBD_MSC : public Adafruit_USBD_Interface {
   }
 
   void setReadyCallback(ready_callback_t cb) { setReadyCallback(0, cb); }
+  void setWritableCallback(writable_callback_t cb) { setWritableCallback(0, cb); }
 
   // from Adafruit_USBD_Interface
   virtual uint16_t getInterfaceDescriptor(uint8_t itfnum, uint8_t *buf,
                                           uint16_t bufsize);
 
 private:
-  enum { MAX_LUN = 2 };
+  enum { MAX_LUN = 2 }; // TODO make it configurable
   struct {
     read_callback_t rd_cb;
     write_callback_t wr_cb;
     flush_callback_t fl_cb;
     ready_callback_t ready_cb;
+    writable_callback_t writable_cb;
 
     const char *_inquiry_vid;
     const char *_inquiry_pid;
@@ -107,6 +111,7 @@ class Adafruit_USBD_MSC : public Adafruit_USBD_Interface {
   friend int32_t tud_msc_write10_cb(uint8_t lun, uint32_t lba, uint32_t offset,
                                     uint8_t *buffer, uint32_t bufsize);
   friend void tud_msc_write10_complete_cb(uint8_t lun);
+  friend bool tud_msc_is_writable_cb(uint8_t lun);
 };
 
 #endif /* ADAFRUIT_USBD_MSC_H_ */