dma: move dma_ops to dma-uclass.h

Move dma_ops to a separate header file, following other uclass
implementations. While doing so, this patch also improves dma_ops
documentation.

Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>

drivers/dma/dma-uclass.c

@@ -9,10 +9,10 @@
  */
 
 #include <common.h>
-#include <dma.h>
 #include <dm.h>
 #include <dm/uclass-internal.h>
 #include <dm/device-internal.h>
+#include <dma-uclass.h>
 #include <errno.h>
 
 int dma_get_device(u32 transfer_type, struct udevice **devp)

drivers/dma/ti-edma3.c

@@ -11,7 +11,7 @@
 #include <asm/io.h>
 #include <common.h>
 #include <dm.h>
-#include <dma.h>
+#include <dma-uclass.h>
 #include <asm/omap_common.h>
 #include <asm/ti-common/ti-edma3.h>
 

include/dma-uclass.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
+ * Copyright (C) 2015 Texas Instruments Incorporated <www.ti.com>
+ * Written by Mugunthan V N <mugunthanvnm@ti.com>
+ *
+ */
+
+#ifndef _DMA_UCLASS_H
+#define _DMA_UCLASS_H
+
+/* See dma.h for background documentation. */
+
+#include <dma.h>
+
+/*
+ * struct dma_ops - Driver model DMA operations
+ *
+ * The uclass interface is implemented by all DMA devices which use
+ * driver model.
+ */
+struct dma_ops {
+	/**
+	 * transfer() - Issue a DMA transfer. The implementation must
+	 *   wait until the transfer is done.
+	 *
+	 * @dev: The DMA device
+	 * @direction: direction of data transfer (should be one from
+	 *   enum dma_direction)
+	 * @dst: The destination pointer.
+	 * @src: The source pointer.
+	 * @len: Length of the data to be copied (number of bytes).
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*transfer)(struct udevice *dev, int direction, void *dst,
+			void *src, size_t len);
+};
+
+#endif /* _DMA_UCLASS_H */

include/dma.h

@@ -26,28 +26,6 @@ enum dma_direction {
 #define DMA_SUPPORTS_DEV_TO_MEM	BIT(2)
 #define DMA_SUPPORTS_DEV_TO_DEV	BIT(3)
 
-/*
- * struct dma_ops - Driver model DMA operations
- *
- * The uclass interface is implemented by all DMA devices which use
- * driver model.
- */
-struct dma_ops {
-	/*
-	 * Get the current timer count
-	 *
-	 * @dev: The DMA device
-	 * @direction: direction of data transfer should be one from
-		       enum dma_direction
-	 * @dst: Destination pointer
-	 * @src: Source pointer
-	 * @len: Length of the data to be copied.
-	 * @return: 0 if OK, -ve on error
-	 */
-	int (*transfer)(struct udevice *dev, int direction, void *dst,
-			void *src, size_t len);
-};
-
 /*
  * struct dma_dev_priv - information about a device used by the uclass
  *