mirror of
https://github.com/AsahiLinux/u-boot
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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>
This commit is contained in:
Álvaro Fernández Rojas
Tom Rini
parent
10b4dc5208
commit
27ab27f850
4 changed files with 532 additions and 7 deletions
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@ -12,6 +12,13 @@ config DMA
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buses that is used to transfer data to and from memory.
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The uclass interface is defined in include/dma.h.
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config DMA_CHANNELS
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bool "Enable DMA channels support"
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depends on DMA
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help
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Enable channels support for DMA. Some DMA controllers have multiple
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channels which can either transfer data to/from different devices.
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config TI_EDMA3
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bool "TI EDMA3 driver"
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help
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@ -2,19 +2,192 @@
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/*
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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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* Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
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* Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
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* Written by Mugunthan V N <mugunthanvnm@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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#include <common.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 <dm/read.h>
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#include <dma-uclass.h>
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#include <dt-structs.h>
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#include <errno.h>
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#ifdef CONFIG_DMA_CHANNELS
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static inline struct dma_ops *dma_dev_ops(struct udevice *dev)
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{
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return (struct dma_ops *)dev->driver->ops;
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}
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# if CONFIG_IS_ENABLED(OF_CONTROL)
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static int dma_of_xlate_default(struct dma *dma,
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struct ofnode_phandle_args *args)
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{
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debug("%s(dma=%p)\n", __func__, dma);
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if (args->args_count > 1) {
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pr_err("Invaild args_count: %d\n", args->args_count);
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return -EINVAL;
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}
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if (args->args_count)
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dma->id = args->args[0];
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else
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dma->id = 0;
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return 0;
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}
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int dma_get_by_index(struct udevice *dev, int index, struct dma *dma)
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{
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int ret;
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struct ofnode_phandle_args args;
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struct udevice *dev_dma;
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const struct dma_ops *ops;
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debug("%s(dev=%p, index=%d, dma=%p)\n", __func__, dev, index, dma);
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assert(dma);
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dma->dev = NULL;
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ret = dev_read_phandle_with_args(dev, "dmas", "#dma-cells", 0, index,
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&args);
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if (ret) {
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pr_err("%s: dev_read_phandle_with_args failed: err=%d\n",
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__func__, ret);
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return ret;
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}
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ret = uclass_get_device_by_ofnode(UCLASS_DMA, args.node, &dev_dma);
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if (ret) {
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pr_err("%s: uclass_get_device_by_ofnode failed: err=%d\n",
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__func__, ret);
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return ret;
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}
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dma->dev = dev_dma;
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ops = dma_dev_ops(dev_dma);
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if (ops->of_xlate)
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ret = ops->of_xlate(dma, &args);
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else
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ret = dma_of_xlate_default(dma, &args);
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if (ret) {
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pr_err("of_xlate() failed: %d\n", ret);
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return ret;
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}
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return dma_request(dev_dma, dma);
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}
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int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma)
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{
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int index;
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debug("%s(dev=%p, name=%s, dma=%p)\n", __func__, dev, name, dma);
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dma->dev = NULL;
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index = dev_read_stringlist_search(dev, "dma-names", name);
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if (index < 0) {
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pr_err("dev_read_stringlist_search() failed: %d\n", index);
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return index;
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}
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return dma_get_by_index(dev, index, dma);
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}
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# endif /* OF_CONTROL */
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int dma_request(struct udevice *dev, struct dma *dma)
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{
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struct dma_ops *ops = dma_dev_ops(dev);
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debug("%s(dev=%p, dma=%p)\n", __func__, dev, dma);
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dma->dev = dev;
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if (!ops->request)
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return 0;
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return ops->request(dma);
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}
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int dma_free(struct dma *dma)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->free)
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return 0;
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return ops->free(dma);
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}
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int dma_enable(struct dma *dma)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->enable)
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return -ENOSYS;
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return ops->enable(dma);
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}
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int dma_disable(struct dma *dma)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->disable)
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return -ENOSYS;
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return ops->disable(dma);
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}
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int dma_prepare_rcv_buf(struct dma *dma, void *dst, size_t size)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->prepare_rcv_buf)
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return -1;
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return ops->prepare_rcv_buf(dma, dst, size);
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}
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int dma_receive(struct dma *dma, void **dst, void *metadata)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->receive)
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return -ENOSYS;
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return ops->receive(dma, dst, metadata);
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}
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int dma_send(struct dma *dma, void *src, size_t len, void *metadata)
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{
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struct dma_ops *ops = dma_dev_ops(dma->dev);
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debug("%s(dma=%p)\n", __func__, dma);
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if (!ops->send)
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return -ENOSYS;
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return ops->send(dma, src, len, metadata);
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}
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#endif /* CONFIG_DMA_CHANNELS */
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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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@ -1,7 +1,7 @@
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/* SPDX-License-Identifier: GPL-2.0+ */
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/*
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* Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
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* Copyright (C) 2015 Texas Instruments Incorporated <www.ti.com>
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* Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
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* Written by Mugunthan V N <mugunthanvnm@ti.com>
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*
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*/
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@ -13,6 +13,8 @@
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#include <dma.h>
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struct ofnode_phandle_args;
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/*
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* struct dma_ops - Driver model DMA operations
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*
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@ -20,6 +22,93 @@
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* driver model.
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*/
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struct dma_ops {
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#ifdef CONFIG_DMA_CHANNELS
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/**
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* of_xlate - Translate a client's device-tree (OF) DMA specifier.
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*
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* The DMA core calls this function as the first step in implementing
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* a client's dma_get_by_*() call.
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*
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* If this function pointer is set to NULL, the DMA core will use a
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* default implementation, which assumes #dma-cells = <1>, and that
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* the DT cell contains a simple integer DMA Channel.
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*
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* At present, the DMA API solely supports device-tree. If this
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* changes, other xxx_xlate() functions may be added to support those
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* other mechanisms.
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*
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* @dma: The dma struct to hold the translation result.
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* @args: The dma specifier values from device tree.
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* @return 0 if OK, or a negative error code.
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*/
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int (*of_xlate)(struct dma *dma,
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struct ofnode_phandle_args *args);
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/**
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* request - Request a translated DMA.
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*
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* The DMA core calls this function as the second step in
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* implementing a client's dma_get_by_*() call, following a successful
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* xxx_xlate() call, or as the only step in implementing a client's
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* dma_request() call.
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*
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* @dma: The DMA struct to request; this has been filled in by
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* a previoux xxx_xlate() function call, or by the caller of
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* dma_request().
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* @return 0 if OK, or a negative error code.
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*/
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int (*request)(struct dma *dma);
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/**
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* free - Free a previously requested dma.
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*
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* This is the implementation of the client dma_free() API.
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*
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* @dma: The DMA to free.
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* @return 0 if OK, or a negative error code.
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*/
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int (*free)(struct dma *dma);
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/**
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* enable() - Enable a DMA Channel.
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*
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* @dma: The DMA Channel to manipulate.
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* @return zero on success, or -ve error code.
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*/
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int (*enable)(struct dma *dma);
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/**
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* disable() - Disable a DMA Channel.
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*
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* @dma: The DMA Channel to manipulate.
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* @return zero on success, or -ve error code.
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*/
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int (*disable)(struct dma *dma);
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/**
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* prepare_rcv_buf() - Prepare/Add receive DMA buffer.
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*
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* @dma: The DMA Channel to manipulate.
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* @dst: The receive buffer pointer.
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* @size: The receive buffer size
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* @return zero on success, or -ve error code.
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*/
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int (*prepare_rcv_buf)(struct dma *dma, void *dst, size_t size);
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/**
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* receive() - Receive a DMA transfer.
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*
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* @dma: The DMA Channel to manipulate.
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* @dst: The destination pointer.
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* @metadata: DMA driver's specific data
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* @return zero on success, or -ve error code.
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*/
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int (*receive)(struct dma *dma, void **dst, void *metadata);
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/**
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* send() - Send a DMA transfer.
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*
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* @dma: The DMA Channel to manipulate.
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* @src: The source pointer.
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* @len: Length of the data to be sent (number of bytes).
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* @metadata: DMA driver's specific data
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* @return zero on success, or -ve error code.
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*/
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int (*send)(struct dma *dma, void *src, size_t len, void *metadata);
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#endif /* CONFIG_DMA_CHANNELS */
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/**
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* transfer() - Issue a DMA transfer. The implementation must
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* wait until the transfer is done.
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260
include/dma.h
260
include/dma.h
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@ -1,12 +1,17 @@
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/* SPDX-License-Identifier: GPL-2.0+ */
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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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* Copyright (C) 2018 Álvaro Fernández Rojas <noltari@gmail.com>
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* Copyright (C) 2015 - 2018 Texas Instruments Incorporated <www.ti.com>
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* Written by Mugunthan V N <mugunthanvnm@ti.com>
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*
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*/
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#ifndef _DMA_H_
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#define _DMA_H_
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#include <linux/errno.h>
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#include <linux/types.h>
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/*
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* enum dma_direction - dma transfer direction indicator
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* @DMA_MEM_TO_MEM: Memcpy mode
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@ -36,6 +41,257 @@ struct dma_dev_priv {
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u32 supported;
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};
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#ifdef CONFIG_DMA_CHANNELS
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/**
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* A DMA is a feature of computer systems that allows certain hardware
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* subsystems to access main system memory, independent of the CPU.
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* DMA channels are typically generated externally to the HW module
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* consuming them, by an entity this API calls a DMA provider. This API
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* provides a standard means for drivers to enable and disable DMAs, and to
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* copy, send and receive data using DMA.
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*
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* A driver that implements UCLASS_DMA is a DMA provider. A provider will
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* often implement multiple separate DMAs, since the hardware it manages
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* often has this capability. dma_uclass.h describes the interface which
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* DMA providers must implement.
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*
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* DMA consumers/clients are the HW modules driven by the DMA channels. This
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* header file describes the API used by drivers for those HW modules.
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*
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* DMA consumer DMA_MEM_TO_DEV (transmit) usage example (based on networking).
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* Note. dma_send() is sync operation always - it'll start transfer and will
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* poll for it to complete:
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* - get/request dma channel
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* struct dma dma_tx;
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* ret = dma_get_by_name(common->dev, "tx0", &dma_tx);
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* if (ret) ...
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*
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* - enable dma channel
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* ret = dma_enable(&dma_tx);
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* if (ret) ...
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*
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* - dma transmit DMA_MEM_TO_DEV.
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* struct ti_drv_packet_data packet_data;
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*
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* packet_data.opt1 = val1;
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* packet_data.opt2 = val2;
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* ret = dma_send(&dma_tx, packet, length, &packet_data);
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* if (ret) ..
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*
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* DMA consumer DMA_DEV_TO_MEM (receive) usage example (based on networking).
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* Note. dma_receive() is sync operation always - it'll start transfer
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* (if required) and will poll for it to complete (or for any previously
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* configured dev2mem transfer to complete):
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* - get/request dma channel
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* struct dma dma_rx;
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* ret = dma_get_by_name(common->dev, "rx0", &dma_rx);
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* if (ret) ...
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*
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* - enable dma channel
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* ret = dma_enable(&dma_rx);
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* if (ret) ...
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*
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* - dma receive DMA_DEV_TO_MEM.
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* struct ti_drv_packet_data packet_data;
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*
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* len = dma_receive(&dma_rx, (void **)packet, &packet_data);
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* if (ret < 0) ...
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*
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* DMA consumer DMA_DEV_TO_MEM (receive) zero-copy usage example (based on
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* networking). Networking subsystem allows to configure and use few receive
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* buffers (dev2mem), as Networking RX DMA channels usually implemented
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* as streaming interface
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* - get/request dma channel
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* struct dma dma_rx;
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* ret = dma_get_by_name(common->dev, "rx0", &dma_rx);
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* if (ret) ...
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*
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* for (i = 0; i < RX_DESC_NUM; i++) {
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* ret = dma_prepare_rcv_buf(&dma_rx,
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* net_rx_packets[i],
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* RX_BUF_SIZE);
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* if (ret) ...
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* }
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*
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* - enable dma channel
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* ret = dma_enable(&dma_rx);
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* if (ret) ...
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*
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* - dma receive DMA_DEV_TO_MEM.
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* struct ti_drv_packet_data packet_data;
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*
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* len = dma_receive(&dma_rx, (void **)packet, &packet_data);
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* if (ret < 0) ..
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*
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* -- process packet --
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*
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* - return buffer back to DAM channel
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* ret = dma_prepare_rcv_buf(&dma_rx,
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* net_rx_packets[rx_next],
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* RX_BUF_SIZE);
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*/
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struct udevice;
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/**
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* struct dma - A handle to (allowing control of) a single DMA.
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*
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* Clients provide storage for DMA handles. The content of the structure is
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* managed solely by the DMA API and DMA drivers. A DMA struct is
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* initialized by "get"ing the DMA struct. The DMA struct is passed to all
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* other DMA APIs to identify which DMA channel to operate upon.
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*
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* @dev: The device which implements the DMA channel.
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* @id: The DMA channel ID within the provider.
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*
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* Currently, the DMA API assumes that a single integer ID is enough to
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* identify and configure any DMA channel for any DMA provider. If this
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* assumption becomes invalid in the future, the struct could be expanded to
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* either (a) add more fields to allow DMA providers to store additional
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* information, or (b) replace the id field with an opaque pointer, which the
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* provider would dynamically allocated during its .of_xlate op, and process
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* during is .request op. This may require the addition of an extra op to clean
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* up the allocation.
|
||||
*/
|
||||
struct dma {
|
||||
struct udevice *dev;
|
||||
/*
|
||||
* Written by of_xlate. We assume a single id is enough for now. In the
|
||||
* future, we might add more fields here.
|
||||
*/
|
||||
unsigned long id;
|
||||
};
|
||||
|
||||
# if CONFIG_IS_ENABLED(OF_CONTROL) && CONFIG_IS_ENABLED(DMA)
|
||||
/**
|
||||
* dma_get_by_index - Get/request a DMA by integer index.
|
||||
*
|
||||
* This looks up and requests a DMA. The index is relative to the client
|
||||
* device; each device is assumed to have n DMAs associated with it somehow,
|
||||
* and this function finds and requests one of them. The mapping of client
|
||||
* device DMA indices to provider DMAs may be via device-tree properties,
|
||||
* board-provided mapping tables, or some other mechanism.
|
||||
*
|
||||
* @dev: The client device.
|
||||
* @index: The index of the DMA to request, within the client's list of
|
||||
* DMA channels.
|
||||
* @dma: A pointer to a DMA struct to initialize.
|
||||
* @return 0 if OK, or a negative error code.
|
||||
*/
|
||||
int dma_get_by_index(struct udevice *dev, int index, struct dma *dma);
|
||||
|
||||
/**
|
||||
* dma_get_by_name - Get/request a DMA by name.
|
||||
*
|
||||
* This looks up and requests a DMA. The name is relative to the client
|
||||
* device; each device is assumed to have n DMAs associated with it somehow,
|
||||
* and this function finds and requests one of them. The mapping of client
|
||||
* device DMA names to provider DMAs may be via device-tree properties,
|
||||
* board-provided mapping tables, or some other mechanism.
|
||||
*
|
||||
* @dev: The client device.
|
||||
* @name: The name of the DMA to request, within the client's list of
|
||||
* DMA channels.
|
||||
* @dma: A pointer to a DMA struct to initialize.
|
||||
* @return 0 if OK, or a negative error code.
|
||||
*/
|
||||
int dma_get_by_name(struct udevice *dev, const char *name, struct dma *dma);
|
||||
# else
|
||||
static inline int dma_get_by_index(struct udevice *dev, int index,
|
||||
struct dma *dma)
|
||||
{
|
||||
return -ENOSYS;
|
||||
}
|
||||
|
||||
static inline int dma_get_by_name(struct udevice *dev, const char *name,
|
||||
struct dma *dma)
|
||||
{
|
||||
return -ENOSYS;
|
||||
}
|
||||
# endif
|
||||
|
||||
/**
|
||||
* dma_request - Request a DMA by provider-specific ID.
|
||||
*
|
||||
* This requests a DMA using a provider-specific ID. Generally, this function
|
||||
* should not be used, since dma_get_by_index/name() provide an interface that
|
||||
* better separates clients from intimate knowledge of DMA providers.
|
||||
* However, this function may be useful in core SoC-specific code.
|
||||
*
|
||||
* @dev: The DMA provider device.
|
||||
* @dma: A pointer to a DMA struct to initialize. The caller must
|
||||
* have already initialized any field in this struct which the
|
||||
* DMA provider uses to identify the DMA channel.
|
||||
* @return 0 if OK, or a negative error code.
|
||||
*/
|
||||
int dma_request(struct udevice *dev, struct dma *dma);
|
||||
|
||||
/**
|
||||
* dma_free - Free a previously requested DMA.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @return 0 if OK, or a negative error code.
|
||||
*/
|
||||
int dma_free(struct dma *dma);
|
||||
|
||||
/**
|
||||
* dma_enable() - Enable (turn on) a DMA channel.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @return zero on success, or -ve error code.
|
||||
*/
|
||||
int dma_enable(struct dma *dma);
|
||||
|
||||
/**
|
||||
* dma_disable() - Disable (turn off) a DMA channel.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @return zero on success, or -ve error code.
|
||||
*/
|
||||
int dma_disable(struct dma *dma);
|
||||
|
||||
/**
|
||||
* dma_prepare_rcv_buf() - Prepare/add receive DMA buffer.
|
||||
*
|
||||
* It allows to implement zero-copy async DMA_DEV_TO_MEM (receive) transactions
|
||||
* if supported by DMA providers.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @dst: The receive buffer pointer.
|
||||
* @size: The receive buffer size
|
||||
* @return zero on success, or -ve error code.
|
||||
*/
|
||||
int dma_prepare_rcv_buf(struct dma *dma, void *dst, size_t size);
|
||||
|
||||
/**
|
||||
* dma_receive() - Receive a DMA transfer.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @dst: The destination pointer.
|
||||
* @metadata: DMA driver's channel specific data
|
||||
* @return length of received data on success, or zero - no data,
|
||||
* or -ve error code.
|
||||
*/
|
||||
int dma_receive(struct dma *dma, void **dst, void *metadata);
|
||||
|
||||
/**
|
||||
* dma_send() - Send a DMA transfer.
|
||||
*
|
||||
* @dma: A DMA struct that was previously successfully requested by
|
||||
* dma_request/get_by_*().
|
||||
* @src: The source pointer.
|
||||
* @len: Length of the data to be sent (number of bytes).
|
||||
* @metadata: DMA driver's channel specific data
|
||||
* @return zero on success, or -ve error code.
|
||||
*/
|
||||
int dma_send(struct dma *dma, void *src, size_t len, void *metadata);
|
||||
#endif /* CONFIG_DMA_CHANNELS */
|
||||
|
||||
/*
|
||||
* dma_get_device - get a DMA device which supports transfer
|
||||
* type of transfer_type
|
||||
|
|
|
|||
Loading…
Reference in a new issue