Add direct-access methods to the base Device class, so that there's a common way of talking to drivers regardless of which of the specialised classes they derive from.

Make the Device destructor public and virtual, so that arbitrary devices can be deleted. Likewise for classes that derive from it.

Make Device::init public so that arbitrary devices can be initialised after being returned by factories.

src/drivers/device/device.cpp

@@ -223,5 +223,22 @@ interrupt(int irq, void *context)
 	return OK;
 }
 
+int
+Device::read(unsigned offset, void *data, unsigned count)
+{
+	return -ENODEV;
+}
 
-} // namespace device
+int
+Device::write(unsigned offset, void *data, unsigned count)
+{
+	return -ENODEV;
+}
+
+int
+Device::ioctl(unsigned operation, unsigned &arg)
+{
+	return -ENODEV;
+}
+
+} // namespace device

src/drivers/device/device.h

@@ -68,11 +68,62 @@ namespace device __EXPORT
 class __EXPORT Device
 {
 public:
+	/**
+	 * Destructor.
+	 *
+	 * Public so that anonymous devices can be destroyed.
+	 */
+	virtual ~Device();
+
 	/**
 	 * Interrupt handler.
 	 */
 	virtual void	interrupt(void *ctx);	/**< interrupt handler */
 
+	/*
+	 * Direct access methods.
+	 */
+
+	/**
+	 * Initialise the driver and make it ready for use.
+	 *
+	 * @return	OK if the driver initialized OK, negative errno otherwise;
+	 */
+	virtual int	init();
+
+	/**
+	 * Read directly from the device.
+	 *
+	 * The actual size of each unit quantity is device-specific.
+	 *
+	 * @param offset	The device address at which to start reading
+	 * @param data		The buffer into which the read values should be placed.
+	 * @param count		The number of items to read.
+	 * @return		The number of items read on success, negative errno otherwise.
+	 */
+	virtual int	read(unsigned address, void *data, unsigned count);
+
+	/**
+	 * Write directly to the device.
+	 *
+	 * The actual size of each unit quantity is device-specific.
+	 *
+	 * @param address	The device address at which to start writing.
+	 * @param data		The buffer from which values should be read.
+	 * @param count		The number of items to write.
+	 * @return		The number of items written on success, negative errno otherwise.
+	 */	 
+	virtual int	write(unsigned address, void *data, unsigned count);
+
+	/**
+	 * Perform a device-specific operation.
+	 *
+	 * @param operation	The operation to perform.
+	 * @param arg		An argument to the operation.
+	 * @return		Negative errno on error, OK or positive value on success.
+	 */
+	virtual int	ioctl(unsigned operation, unsigned &arg);
+
 protected:
 	const char	*_name;			/**< driver name */
 	bool		_debug_enabled;		/**< if true, debug messages are printed */
@@ -85,14 +136,6 @@ protected:
 	 */
 	Device(const char *name,
 	       int irq = 0);
-	~Device();
-
-	/**
-	 * Initialise the driver and make it ready for use.
-	 *
-	 * @return	OK if the driver initialised OK.
-	 */
-	virtual int	init();
 
 	/**
 	 * Enable the device interrupt
@@ -189,7 +232,7 @@ public:
 	/**
 	 * Destructor
 	 */
-	~CDev();
+	virtual ~CDev();
 
 	virtual int	init();
 
@@ -282,6 +325,7 @@ public:
 	 * Test whether the device is currently open.
 	 *
 	 * This can be used to avoid tearing down a device that is still active.
+	 * Note - not virtual, cannot be overridden by a subclass.
 	 *
 	 * @return              True if the device is currently open.
 	 */
@@ -396,9 +440,9 @@ public:
 	    const char *devname,
 	    uint32_t base,
 	    int irq = 0);
-	~PIO();
+	virtual ~PIO();
 
-	int		init();
+	virtual int	init();
 
 protected:
 
@@ -407,7 +451,7 @@ protected:
 	 *
 	 * @param offset	Register offset in bytes from the base address.
 	 */
-	uint32_t reg(uint32_t offset) {
+	uint32_t	reg(uint32_t offset) {
 		return *(volatile uint32_t *)(_base + offset);
 	}
 
@@ -444,4 +488,4 @@ private:
 
 } // namespace device
 
-#endif /* _DEVICE_DEVICE_H */
+#endif /* _DEVICE_DEVICE_H */

src/drivers/device/i2c.h

@@ -55,13 +55,11 @@ class __EXPORT I2C : public CDev
 
 public:
 
-    /**
-     * Get the address
-     */
-    uint16_t get_address() {
-      return _address;
-    }
-
+	/**
+	 * Get the address
+	 */
+	int16_t		get_address() { return _address; }
+	
 protected:
 	/**
 	 * The number of times a read or write operation will be retried on
@@ -90,7 +88,7 @@ protected:
 	    uint16_t address,
 	    uint32_t frequency,
 	    int irq = 0);
-	~I2C();
+	virtual ~I2C();
 
 	virtual int	init();
 

src/drivers/device/spi.h

@@ -71,7 +71,7 @@ protected:
 	    enum spi_mode_e mode,
 	    uint32_t frequency,
 	    int irq = 0);
-	~SPI();
+	virtual ~SPI();
 
 	virtual int	init();