u-boot/drivers/dma/dma-uclass.c
Mugunthan V N a0594cefb7 dm: implement a DMA uclass
Implement a DMA uclass so that the devices like ethernet, spi,
mmc etc can offload the data transfers from/to the device and
memory.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Jagan Teki <jteki@openedev.com>
2016-02-23 16:14:45 +05:30

72 lines
1.5 KiB
C

/*
* Direct Memory Access U-Class driver
*
* (C) Copyright 2015
* Texas Instruments Incorporated, <www.ti.com>
*
* Author: Mugunthan V N <mugunthanvnm@ti.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dma.h>
#include <dm.h>
#include <dm/uclass-internal.h>
#include <dm/device-internal.h>
#include <errno.h>
DECLARE_GLOBAL_DATA_PTR;
int dma_get_device(u32 transfer_type, struct udevice **devp)
{
struct udevice *dev;
int ret;
for (ret = uclass_first_device(UCLASS_DMA, &dev); dev && !ret;
ret = uclass_next_device(&dev)) {
struct dma_dev_priv *uc_priv;
uc_priv = dev_get_uclass_priv(dev);
if (uc_priv->supported & transfer_type)
break;
}
if (!dev) {
error("No DMA device found that supports %x type\n",
transfer_type);
return -EPROTONOSUPPORT;
}
*devp = dev;
return ret;
}
int dma_memcpy(void *dst, void *src, size_t len)
{
struct udevice *dev;
const struct dma_ops *ops;
int ret;
ret = dma_get_device(DMA_SUPPORTS_MEM_TO_MEM, &dev);
if (ret < 0)
return ret;
ops = device_get_ops(dev);
if (!ops->transfer)
return -ENOSYS;
/* Invalidate the area, so no writeback into the RAM races with DMA */
invalidate_dcache_range((unsigned long)dst, (unsigned long)dst +
roundup(len, ARCH_DMA_MINALIGN));
return ops->transfer(dev, DMA_MEM_TO_MEM, dst, src, len);
}
UCLASS_DRIVER(dma) = {
.id = UCLASS_DMA,
.name = "dma",
.flags = DM_UC_FLAG_SEQ_ALIAS,
.per_device_auto_alloc_size = sizeof(struct dma_dev_priv),
};