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