linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Platform driver for the Synopsys DesignWare DMA Controller

 *

 * Copyright (C) 2007-2008 Atmel Corporation

 * Copyright (C) 2010-2011 ST Microelectronics

 * Copyright (C) 2013 Intel Corporation

 *

 * Some parts of this driver are derived from the original dw_dmac.

 */

​

#include <linux/module.h>

#include <linux/device.h>

#include <linux/clk.h>

#include <linux/pm_runtime.h>

#include <linux/platform_device.h>

#include <linux/dmaengine.h>

#include <linux/dma-mapping.h>

#include <linux/of.h>

#include <linux/of_dma.h>

#include <linux/acpi.h>

#include <linux/acpi_dma.h>

​

#include "internal.h"

​

#define DRV_NAME    "dw_dmac"

​

static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,

                    struct of_dma *ofdma)

{

    struct dw_dma *dw = ofdma->of_dma_data;

    struct dw_dma_slave slave = {

        .dma_dev = dw->dma.dev,

    };

    dma_cap_mask_t cap;

​

    if (dma_spec->args_count != 3)

        return NULL;

​

    slave.src_id = dma_spec->args[0];

    slave.dst_id = dma_spec->args[0];

    slave.m_master = dma_spec->args[1];

    slave.p_master = dma_spec->args[2];

​

    if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||

            slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||

            slave.m_master >= dw->pdata->nr_masters ||

            slave.p_master >= dw->pdata->nr_masters))

        return NULL;

​

    dma_cap_zero(cap);

    dma_cap_set(DMA_SLAVE, cap);

​

    /* TODO: there should be a simpler way to do this */

    return dma_request_channel(cap, dw_dma_filter, &slave);

}

​

#ifdef CONFIG_ACPI

static bool dw_dma_acpi_filter(struct dma_chan *chan, void *param)

{

    struct acpi_dma_spec *dma_spec = param;

    struct dw_dma_slave slave = {

        .dma_dev = dma_spec->dev,