dma: add channels support

This adds channels support for dma controllers that have multiple channels
which can transfer data to/from different devices (enet, usb...).

DMA channle API:
 dma_get_by_index()
 dma_get_by_name()
 dma_request()
 dma_free()
 dma_enable()
 dma_disable()
 dma_prepare_rcv_buf()
 dma_receive()
 dma_send()

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
[grygorii.strashko@ti.com: drop unused dma_get_by_index_platdata(),
 add metadata to send/receive ops, add dma_prepare_rcv_buf(),
 minor clean up]
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 90 insertions, 1 deletions

diff --git a/include/dma-uclass.h b/include/dma-uclass.h
index 7bec5d33990..31b43fb4b98 100644
--- a/include/dma-uclass.h
+++ b/include/dma-uclass.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0+ */
 /*
  * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
- * Copyright (C) 2015 Texas Instruments Incorporated <www.ti.com>
+ * Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
  * Written by Mugunthan V N <mugunthanvnm@ti.com>
  *
  */
@@ -13,6 +13,8 @@
 
 #include <dma.h>
 
+struct ofnode_phandle_args;
+
 /*
  * struct dma_ops - Driver model DMA operations
  *
@@ -20,6 +22,93 @@
  * driver model.
  */
 struct dma_ops {
+#ifdef CONFIG_DMA_CHANNELS
+	/**
+	 * of_xlate - Translate a client's device-tree (OF) DMA specifier.
+	 *
+	 * The DMA core calls this function as the first step in implementing
+	 * a client's dma_get_by_*() call.
+	 *
+	 * If this function pointer is set to NULL, the DMA core will use a
+	 * default implementation, which assumes #dma-cells = <1>, and that
+	 * the DT cell contains a simple integer DMA Channel.
+	 *
+	 * At present, the DMA API solely supports device-tree. If this
+	 * changes, other xxx_xlate() functions may be added to support those
+	 * other mechanisms.
+	 *
+	 * @dma: The dma struct to hold the translation result.
+	 * @args:	The dma specifier values from device tree.
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*of_xlate)(struct dma *dma,
+			struct ofnode_phandle_args *args);
+	/**
+	 * request - Request a translated DMA.
+	 *
+	 * The DMA core calls this function as the second step in
+	 * implementing a client's dma_get_by_*() call, following a successful
+	 * xxx_xlate() call, or as the only step in implementing a client's
+	 * dma_request() call.
+	 *
+	 * @dma: The DMA struct to request; this has been filled in by
+	 *   a previoux xxx_xlate() function call, or by the caller of
+	 *   dma_request().
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*request)(struct dma *dma);
+	/**
+	 * free - Free a previously requested dma.
+	 *
+	 * This is the implementation of the client dma_free() API.
+	 *
+	 * @dma: The DMA to free.
+	 * @return 0 if OK, or a negative error code.
+	 */
+	int (*free)(struct dma *dma);
+	/**
+	 * enable() - Enable a DMA Channel.
+	 *
+	 * @dma: The DMA Channel to manipulate.
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*enable)(struct dma *dma);
+	/**
+	 * disable() - Disable a DMA Channel.
+	 *
+	 * @dma: The DMA Channel to manipulate.
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*disable)(struct dma *dma);
+	/**
+	 * prepare_rcv_buf() - Prepare/Add receive DMA buffer.
+	 *
+	 * @dma: The DMA Channel to manipulate.
+	 * @dst: The receive buffer pointer.
+	 * @size: The receive buffer size
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*prepare_rcv_buf)(struct dma *dma, void *dst, size_t size);
+	/**
+	 * receive() - Receive a DMA transfer.
+	 *
+	 * @dma: The DMA Channel to manipulate.
+	 * @dst: The destination pointer.
+	 * @metadata: DMA driver's specific data
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*receive)(struct dma *dma, void **dst, void *metadata);
+	/**
+	 * send() - Send a DMA transfer.
+	 *
+	 * @dma: The DMA Channel to manipulate.
+	 * @src: The source pointer.
+	 * @len: Length of the data to be sent (number of bytes).
+	 * @metadata: DMA driver's specific data
+	 * @return zero on success, or -ve error code.
+	 */
+	int (*send)(struct dma *dma, void *src, size_t len, void *metadata);
+#endif /* CONFIG_DMA_CHANNELS */
 	/**
 	 * transfer() - Issue a DMA transfer. The implementation must
 	 *   wait until the transfer is done.