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1// SPDX-License-Identifier: GPL-2.02/*3 * Platform driver for the Synopsys DesignWare DMA Controller4 *5 * Copyright (C) 2007-2008 Atmel Corporation6 * Copyright (C) 2010-2011 ST Microelectronics7 * Copyright (C) 2013 Intel Corporation8 */9 10#include <linux/of.h>11#include <linux/of_dma.h>12#include <linux/platform_device.h>13 14#include "internal.h"15 16static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,17 struct of_dma *ofdma)18{19 struct dw_dma *dw = ofdma->of_dma_data;20 struct dw_dma_slave slave = {21 .dma_dev = dw->dma.dev,22 };23 dma_cap_mask_t cap;24 25 if (dma_spec->args_count < 3 || dma_spec->args_count > 4)26 return NULL;27 28 slave.src_id = dma_spec->args[0];29 slave.dst_id = dma_spec->args[0];30 slave.m_master = dma_spec->args[1];31 slave.p_master = dma_spec->args[2];32 if (dma_spec->args_count >= 4)33 slave.channels = dma_spec->args[3];34 35 if (WARN_ON(slave.src_id >= DW_DMA_MAX_NR_REQUESTS ||36 slave.dst_id >= DW_DMA_MAX_NR_REQUESTS ||37 slave.m_master >= dw->pdata->nr_masters ||38 slave.p_master >= dw->pdata->nr_masters ||39 slave.channels >= BIT(dw->pdata->nr_channels)))40 return NULL;41 42 dma_cap_zero(cap);43 dma_cap_set(DMA_SLAVE, cap);44 45 /* TODO: there should be a simpler way to do this */46 return dma_request_channel(cap, dw_dma_filter, &slave);47}48 49struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)50{51 struct device_node *np = pdev->dev.of_node;52 struct dw_dma_platform_data *pdata;53 u32 tmp, arr[DW_DMA_MAX_NR_MASTERS];54 u32 nr_masters;55 u32 nr_channels;56 57 if (of_property_read_u32(np, "dma-masters", &nr_masters))58 return NULL;59 if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)60 return NULL;61 62 if (of_property_read_u32(np, "dma-channels", &nr_channels))63 return NULL;64 if (nr_channels > DW_DMA_MAX_NR_CHANNELS)65 return NULL;66 67 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);68 if (!pdata)69 return NULL;70 71 pdata->nr_masters = nr_masters;72 pdata->nr_channels = nr_channels;73 74 of_property_read_u32(np, "chan_allocation_order", &pdata->chan_allocation_order);75 of_property_read_u32(np, "chan_priority", &pdata->chan_priority);76 77 of_property_read_u32(np, "block_size", &pdata->block_size);78 79 /* Try deprecated property first */80 if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {81 for (tmp = 0; tmp < nr_masters; tmp++)82 pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);83 }84 85 /* If "data_width" and "data-width" both provided use the latter one */86 of_property_read_u32_array(np, "data-width", pdata->data_width, nr_masters);87 88 memset32(pdata->multi_block, 1, nr_channels);89 of_property_read_u32_array(np, "multi-block", pdata->multi_block, nr_channels);90 91 memset32(pdata->max_burst, DW_DMA_MAX_BURST, nr_channels);92 of_property_read_u32_array(np, "snps,max-burst-len", pdata->max_burst, nr_channels);93 94 of_property_read_u32(np, "snps,dma-protection-control", &pdata->protctl);95 if (pdata->protctl > CHAN_PROTCTL_MASK)96 return NULL;97 98 return pdata;99}100 101void dw_dma_of_controller_register(struct dw_dma *dw)102{103 struct device *dev = dw->dma.dev;104 int ret;105 106 if (!dev->of_node)107 return;108 109 ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);110 if (ret)111 dev_err(dev, "could not register of_dma_controller\n");112}113 114void dw_dma_of_controller_free(struct dw_dma *dw)115{116 struct device *dev = dw->dma.dev;117 118 if (!dev->of_node)119 return;120 121 of_dma_controller_free(dev->of_node);122}123