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>

2 files changed, 184 insertions, 4 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 4ee6afad35..b9b85c65fc 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -12,6 +12,13 @@ config DMA
 	  buses that is used to transfer data to and from memory.
 	  The uclass interface is defined in include/dma.h.
 
+config DMA_CHANNELS
+	bool "Enable DMA channels support"
+	depends on DMA
+	help
+	  Enable channels support for DMA. Some DMA controllers have multiple
+	  channels which can either transfer data to/from different devices.
+
 config TI_EDMA3
 	bool "TI EDMA3 driver"
 	help
diff --git a/drivers/dma/dma-uclass.c b/drivers/dma/dma-uclass.c
index 6c3506c302..9c961cf1e2 100644
--- a/drivers/dma/dma-uclass.c
+++ b/drivers/dma/dma-uclass.c
@@ -2,19 +2,192 @@
 /*
  * Direct Memory Access U-Class driver
  *
- * (C) Copyright 2015
- *     Texas Instruments Incorporated, <www.ti.com>
+ * Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
+ * Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
+ * Written by Mugunthan V N <mugunthanvnm@ti.com>
  *
  * Author: Mugunthan V N <mugunthanvnm@ti.com>
  */
 
 #include <common.h>
 #include <dm.h>
-#include <dm/uclass-internal.h>
-#include <dm/device-internal.h>
+#include <dm/read.h>
 #include <dma-uclass.h>
+#include <dt-structs.h>
 #include <errno.h>
 
+#ifdef CONFIG_DMA_CHANNELS
+static inline struct dma_ops *dma_dev_ops(struct udevice *dev)
+{
+	return (struct dma_ops *)dev->driver->ops;
+}
+
+# if CONFIG_IS_ENABLED(OF_CONTROL)
+static int dma_of_xlate_default(struct dma *dma,
+				struct ofnode_phandle_args *args)
+{
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (args->args_count > 1) {
+		pr_err("Invaild args_count: %d\n", args->args_count);
+		return -EINVAL;
+	}
+
+	if (args->args_count)
+		dma->id = args->args[0];
+	else
+		dma->id = 0;
+
+	return 0;
+}
+
+int dma_get_by_index(struct udevice *dev, int index, struct dma *dma)
+{
+	int ret;
+	struct ofnode_phandle_args args;
+	struct udevice *dev_dma;
+	const struct dma_ops *ops;
+
+	debug("%s(dev=%p, index=%d, dma=%p)\n", __func__, dev, index, dma);
+
+	assert(dma);
+	dma->dev = NULL;
+
+	ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, index,
+					 &args);
+	if (ret) {
+		pr_err("%s: dev_read_phandle_with_args failed: err=%d\n",
+		       __func__, ret);
+		return ret;
+	}
+
+	ret = uclass_get_device_by_ofnode(UCLASS_DMA, args.node, &dev_dma);
+	if (ret) {
+		pr_err("%s: uclass_get_device_by_ofnode failed: err=%d\n",
+		       __func__, ret);
+		return ret;
+	}
+
+	dma->dev = dev_dma;
+
+	ops = dma_dev_ops(dev_dma);
+
+	if (ops->of_xlate)
+		ret = ops->of_xlate(dma, &args);
+	else
+		ret = dma_of_xlate_default(dma, &args);
+	if (ret) {
+		pr_err("of_xlate() failed: %d\n", ret);
+		return ret;
+	}
+
+	return dma_request(dev_dma, dma);
+}
+
+int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma)
+{
+	int index;
+
+	debug("%s(dev=%p, name=%s, dma=%p)\n", __func__, dev, name, dma);
+	dma->dev = NULL;
+
+	index = dev_read_stringlist_search(dev, "dma-names", name);
+	if (index < 0) {
+		pr_err("dev_read_stringlist_search() failed: %d\n", index);
+		return index;
+	}
+
+	return dma_get_by_index(dev, index, dma);
+}
+# endif /* OF_CONTROL */
+
+int dma_request(struct udevice *dev, struct dma *dma)
+{
+	struct dma_ops *ops = dma_dev_ops(dev);
+
+	debug("%s(dev=%p, dma=%p)\n", __func__, dev, dma);
+
+	dma->dev = dev;
+
+	if (!ops->request)
+		return 0;
+
+	return ops->request(dma);
+}
+
+int dma_free(struct dma *dma)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->free)
+		return 0;
+
+	return ops->free(dma);
+}
+
+int dma_enable(struct dma *dma)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->enable)
+		return -ENOSYS;
+
+	return ops->enable(dma);
+}
+
+int dma_disable(struct dma *dma)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->disable)
+		return -ENOSYS;
+
+	return ops->disable(dma);
+}
+
+int dma_prepare_rcv_buf(struct dma *dma, void *dst, size_t size)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->prepare_rcv_buf)
+		return -1;
+
+	return ops->prepare_rcv_buf(dma, dst, size);
+}
+
+int dma_receive(struct dma *dma, void **dst, void *metadata)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->receive)
+		return -ENOSYS;
+
+	return ops->receive(dma, dst, metadata);
+}
+
+int dma_send(struct dma *dma, void *src, size_t len, void *metadata)
+{
+	struct dma_ops *ops = dma_dev_ops(dma->dev);
+
+	debug("%s(dma=%p)\n", __func__, dma);
+
+	if (!ops->send)
+		return -ENOSYS;
+
+	return ops->send(dma, src, len, metadata);
+}
+#endif /* CONFIG_DMA_CHANNELS */
+
 int dma_get_device(u32 transfer_type, struct udevice **devp)
 {
 	struct udevice *dev;