123 строки
3.3 KiB
C
123 строки
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Platform driver for the Synopsys DesignWare DMA Controller
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*
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* Copyright (C) 2007-2008 Atmel Corporation
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* Copyright (C) 2010-2011 ST Microelectronics
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* Copyright (C) 2013 Intel Corporation
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*/
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#include <linux/of.h>
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#include <linux/of_dma.h>
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#include <linux/platform_device.h>
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#include "internal.h"
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static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
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struct of_dma *ofdma)
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{
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struct dw_dma *dw = ofdma->of_dma_data;
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struct dw_dma_slave slave = {
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.dma_dev = dw->dma.dev,
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};
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dma_cap_mask_t cap;
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if (dma_spec->args_count < 3 || dma_spec->args_count > 4)
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return NULL;
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slave.src_id = dma_spec->args[0];
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slave.dst_id = dma_spec->args[0];
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slave.m_master = dma_spec->args[1];
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slave.p_master = dma_spec->args[2];
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if (dma_spec->args_count >= 4)
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slave.channels = dma_spec->args[3];
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if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||
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slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||
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slave.m_master >= dw->pdata->nr_masters ||
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slave.p_master >= dw->pdata->nr_masters ||
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slave.channels >= BIT(dw->pdata->nr_channels)))
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return NULL;
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dma_cap_zero(cap);
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dma_cap_set(DMA_SLAVE, cap);
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/* TODO: there should be a simpler way to do this */
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return dma_request_channel(cap, dw_dma_filter, &slave);
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}
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struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
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{
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struct device_node *np = pdev->dev.of_node;
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struct dw_dma_platform_data *pdata;
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u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];
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u32 nr_masters;
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u32 nr_channels;
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if (of_property_read_u32(np, "dma-masters", &nr_masters))
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return NULL;
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if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
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return NULL;
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if (of_property_read_u32(np, "dma-channels", &nr_channels))
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return NULL;
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if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
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return NULL;
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pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
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if (!pdata)
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return NULL;
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pdata->nr_masters = nr_masters;
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pdata->nr_channels = nr_channels;
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of_property_read_u32(np, "chan_allocation_order", &pdata->chan_allocation_order);
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of_property_read_u32(np, "chan_priority", &pdata->chan_priority);
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of_property_read_u32(np, "block_size", &pdata->block_size);
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/* Try deprecated property first */
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if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
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for (tmp = 0; tmp < nr_masters; tmp++)
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pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
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}
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/* If "data_width" and "data-width" both provided use the latter one */
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of_property_read_u32_array(np, "data-width", pdata->data_width, nr_masters);
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memset32(pdata->multi_block, 1, nr_channels);
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of_property_read_u32_array(np, "multi-block", pdata->multi_block, nr_channels);
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memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels);
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of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst, nr_channels);
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of_property_read_u32(np, "snps,dma-protection-control", &pdata->protctl);
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if (pdata->protctl > CHAN_PROTCTL_MASK)
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return NULL;
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return pdata;
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}
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void dw_dma_of_controller_register(struct dw_dma *dw)
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{
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struct device *dev = dw->dma.dev;
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int ret;
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if (!dev->of_node)
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return;
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ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);
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if (ret)
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dev_err(dev, "could not register of_dma_controller\n");
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}
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void dw_dma_of_controller_free(struct dw_dma *dw)
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{
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struct device *dev = dw->dma.dev;
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if (!dev->of_node)
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return;
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of_dma_controller_free(dev->of_node);
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}
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