1 // SPDX-License-Identifier: GPL-2.0
3 * Platform driver for the Synopsys DesignWare DMA Controller
5 * Copyright (C) 2007-2008 Atmel Corporation
6 * Copyright (C) 2010-2011 ST Microelectronics
7 * Copyright (C) 2013 Intel Corporation
11 #include <linux/of_dma.h>
12 #include <linux/platform_device.h>
16 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
19 struct dw_dma *dw = ofdma->of_dma_data;
20 struct dw_dma_slave slave = {
21 .dma_dev = dw->dma.dev,
25 if (dma_spec->args_count < 3 || dma_spec->args_count > 4)
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];
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)))
43 dma_cap_set(DMA_SLAVE, cap);
45 /* TODO: there should be a simpler way to do this */
46 return dma_request_channel(cap, dw_dma_filter, &slave);
49 struct dw_dma_platform_data *dw_dma_parse_dt(struct platform_device *pdev)
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], mb[DW_DMA_MAX_NR_CHANNELS];
58 dev_err(&pdev->dev, "Missing DT data\n");
62 if (of_property_read_u32(np, "dma-masters", &nr_masters))
64 if (nr_masters < 1 || nr_masters > DW_DMA_MAX_NR_MASTERS)
67 if (of_property_read_u32(np, "dma-channels", &nr_channels))
69 if (nr_channels > DW_DMA_MAX_NR_CHANNELS)
72 pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
76 pdata->nr_masters = nr_masters;
77 pdata->nr_channels = nr_channels;
79 if (!of_property_read_u32(np, "chan_allocation_order", &tmp))
80 pdata->chan_allocation_order = (unsigned char)tmp;
82 if (!of_property_read_u32(np, "chan_priority", &tmp))
83 pdata->chan_priority = tmp;
85 if (!of_property_read_u32(np, "block_size", &tmp))
86 pdata->block_size = tmp;
88 if (!of_property_read_u32_array(np, "data-width", arr, nr_masters)) {
89 for (tmp = 0; tmp < nr_masters; tmp++)
90 pdata->data_width[tmp] = arr[tmp];
91 } else if (!of_property_read_u32_array(np, "data_width", arr, nr_masters)) {
92 for (tmp = 0; tmp < nr_masters; tmp++)
93 pdata->data_width[tmp] = BIT(arr[tmp] & 0x07);
96 if (!of_property_read_u32_array(np, "multi-block", mb, nr_channels)) {
97 for (tmp = 0; tmp < nr_channels; tmp++)
98 pdata->multi_block[tmp] = mb[tmp];
100 for (tmp = 0; tmp < nr_channels; tmp++)
101 pdata->multi_block[tmp] = 1;
104 if (!of_property_read_u32(np, "snps,dma-protection-control", &tmp)) {
105 if (tmp > CHAN_PROTCTL_MASK)
107 pdata->protctl = tmp;
113 void dw_dma_of_controller_register(struct dw_dma *dw)
115 struct device *dev = dw->dma.dev;
121 ret = of_dma_controller_register(dev->of_node, dw_dma_of_xlate, dw);
123 dev_err(dev, "could not register of_dma_controller\n");
126 void dw_dma_of_controller_free(struct dw_dma *dw)
128 struct device *dev = dw->dma.dev;
133 of_dma_controller_free(dev->of_node);