dm: implement a Miscellaneous uclass

Implement a Miscellaneous uclass with generic read or
write operations. This class is used only for those
do not fit other more general classes.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 330ecd2..886a44c 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -39,6 +39,7 @@
 	UCLASS_LED,		/* Light-emitting diode (LED) */
 	UCLASS_LPC,		/* x86 'low pin count' interface */
 	UCLASS_MASS_STORAGE,	/* Mass storage device */
+	UCLASS_MISC,		/* Miscellaneous device */
 	UCLASS_MMC,		/* SD / MMC card or chip */
 	UCLASS_MOD_EXP,		/* RSA Mod Exp device */
 	UCLASS_PCH,		/* x86 platform controller hub */
diff --git a/include/misc.h b/include/misc.h
new file mode 100644
index 0000000..7e9badf
--- /dev/null
+++ b/include/misc.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2015 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _MISC_H_
+#define _MISC_H_
+
+/*
+ * Read the device to buffer, optional.
+ *
+ * @dev: the device
+ * @offset: offset to read the device
+ * @buf: pointer to data buffer
+ * @size: data size in bytes to read the device
+ * @return: 0 if OK, -ve on error
+ */
+int misc_read(struct udevice *dev, int offset, void *buf, int size);
+/*
+ * Write buffer to the device, optional.
+ *
+ * @dev: the device
+ * @offset: offset to write the device
+ * @buf: pointer to data buffer
+ * @size: data size in bytes to write the device
+ * @return: 0 if OK, -ve on error
+ */
+int misc_write(struct udevice *dev, int offset, void *buf, int size);
+/*
+ * Assert command to the device, optional.
+ *
+ * @dev: the device
+ * @request: command to be sent to the device
+ * @buf: pointer to buffer related to the requset
+ * @return: 0 if OK, -ve on error
+ */
+int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
+
+/*
+ * struct misc_ops - Driver model Misc operations
+ *
+ * The uclass interface is implemented by all miscellaneous devices which
+ * use driver model.
+ */
+struct misc_ops {
+	/*
+	 * Read the device to buffer, optional.
+	 *
+	 * @dev: the device
+	 * @offset: offset to read the device
+	 * @buf: pointer to data buffer
+	 * @size: data size in bytes to read the device
+	 * @return: 0 if OK, -ve on error
+	 */
+	int (*read)(struct udevice *dev, int offset, void *buf, int size);
+	/*
+	 * Write buffer to the device, optional.
+	 *
+	 * @dev: the device
+	 * @offset: offset to write the device
+	 * @buf: pointer to data buffer
+	 * @size: data size in bytes to write the device
+	 * @return: 0 if OK, -ve on error
+	 */
+	int (*write)(struct udevice *dev, int offset, const void *buf,
+		     int size);
+	/*
+	 * Assert command to the device, optional.
+	 *
+	 * @dev: the device
+	 * @request: command to be sent to the device
+	 * @buf: pointer to buffer related to the requset
+	 * @return: 0 if OK, -ve on error
+	 */
+	int (*ioctl)(struct udevice *dev, unsigned long request, void *buf);
+};
+
+#endif	/* _MISC_H_ */