Commit a0594cef authored by Mugunthan V N's avatar Mugunthan V N Committed by Jagan Teki

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: default avatarMugunthan V N <mugunthanvnm@ti.com>
Reviewed-by: default avatarSimon Glass <sjg@chromium.org>
Reviewed-by: default avatarJagan Teki <jteki@openedev.com>
parent 18c61e95
menu "DMA Support"
config DMA
bool "Enable Driver Model for DMA drivers"
depends on DM
help
Enable driver model for DMA. DMA engines can do
asynchronous data transfers without involving the host
CPU. Currently, this framework can be used to offload
memory copies to and from devices like qspi, ethernet
etc Drivers provide methods to access the DMA devices
buses that is used to transfer data to and from memory.
The uclass interface is defined in include/dma.h.
endmenu # menu "DMA Support"
......@@ -5,6 +5,8 @@
# SPDX-License-Identifier: GPL-2.0+
#
obj-$(CONFIG_DMA) += dma-uclass.o
obj-$(CONFIG_FSLDMAFEC) += MCD_tasksInit.o MCD_dmaApi.o MCD_tasks.o
obj-$(CONFIG_APBH_DMA) += apbh_dma.o
obj-$(CONFIG_FSL_DMA) += fsl_dma.o
......
/*
* 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),
};
......@@ -31,6 +31,7 @@ enum uclass_id {
UCLASS_CROS_EC, /* Chrome OS EC */
UCLASS_DISK, /* Disk controller, e.g. SATA */
UCLASS_DISPLAY, /* Display (e.g. DisplayPort, HDMI) */
UCLASS_DMA, /* Direct Memory Access */
UCLASS_RAM, /* RAM controller */
UCLASS_ETH, /* Ethernet device */
UCLASS_GPIO, /* Bank of general-purpose I/O pins */
......
/*
* (C) Copyright 2015
* Texas Instruments Incorporated, <www.ti.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DMA_H_
#define _DMA_H_
/*
* enum dma_direction - dma transfer direction indicator
* @DMA_MEM_TO_MEM: Memcpy mode
* @DMA_MEM_TO_DEV: From Memory to Device
* @DMA_DEV_TO_MEM: From Device to Memory
* @DMA_DEV_TO_DEV: From Device to Device
*/
enum dma_direction {
DMA_MEM_TO_MEM,
DMA_MEM_TO_DEV,
DMA_DEV_TO_MEM,
DMA_DEV_TO_DEV,
};
#define DMA_SUPPORTS_MEM_TO_MEM BIT(0)
#define DMA_SUPPORTS_MEM_TO_DEV BIT(1)
#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
*
* @supported: mode of transfers that DMA can support, should be
* one/multiple of DMA_SUPPORTS_*
*/
struct dma_dev_priv {
u32 supported;
};
/*
* dma_get_device - get a DMA device which supports transfer
* type of transfer_type
*
* @transfer_type - transfer type should be one/multiple of
* DMA_SUPPORTS_*
* @devp - udevice pointer to return the found device
* @return - will return on success and devp will hold the
* pointer to the device
*/
int dma_get_device(u32 transfer_type, struct udevice **devp);
/*
* dma_memcpy - try to use DMA to do a mem copy which will be
* much faster than CPU mem copy
*
* @dst - destination pointer
* @src - souce pointer
* @len - data length to be copied
* @return - on successful transfer returns no of bytes
transferred and on failure return error code.
*/
int dma_memcpy(void *dst, void *src, size_t len);
#endif /* _DMA_H_ */
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