// 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
 */

#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/platform_device.h>

#include "internal.h"

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 || dma_spec->args_count > 4)
                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 (dma_spec->args_count >= 4)
                slave.channels = dma_spec->args[3];

        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 ||
                    slave.channels >= BIT(dw->pdata->nr_channels)))
                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);
}

struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct dw_dma_platform_data *pdata;
        u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
        u32 nr_masters;
        u32 nr_channels;

        if (of_property_read_u32(np, "dma-masters", &nr_masters))
                return NULL;
        if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
                return NULL;

        if (of_property_read_u32(np, "dma-channels", &nr_channels))
                return NULL;
        if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
                return NULL;

        pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return NULL;

        pdata->nr_masters = nr_masters;
        pdata->nr_channels = nr_channels;

        of_property_read_u32(np, "chan_allocation_order", &pdata->chan_allocation_order);
        of_property_read_u32(np, "chan_priority", &pdata->chan_priority);

        of_property_read_u32(np, "block_size", &pdata->block_size);

        /* Try deprecated property first */
        if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
                for (tmp = 0; tmp < nr_masters; tmp++)
                        pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
        }

        /* If "data_width" and "data-width" both provided use the latter one */
        of_property_read_u32_array(np, "data-width", pdata->data_width, nr_masters);

        memset32(pdata->multi_block, 1, nr_channels);
        of_property_read_u32_array(np, "multi-block", pdata->multi_block, nr_channels);

        memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels);
        of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst, nr_channels);

        of_property_read_u32(np, "snps,dma-protection-control", &pdata->protctl);
        if (pdata->protctl > CHAN_PROTCTL_MASK)
                return NULL;

        return pdata;
}

void dw_dma_of_controller_register(struct dw_dma *dw)
{
        struct device *dev = dw->dma.dev;
        int ret;

        if (!dev->of_node)
                return;

        ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);
        if (ret)
                dev_err(dev, "could not register of_dma_controller\n");
}

void dw_dma_of_controller_free(struct dw_dma *dw)
{
        struct device *dev = dw->dma.dev;

        if (!dev->of_node)
                return;

        of_dma_controller_free(dev->of_node);
}