1 /*
2 * SHDMA Device Tree glue
3 *
4 * Copyright (C) 2013 Renesas Electronics Inc.
5 * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
6 *
7 * This is free software; you can redistribute it and/or modify
8 * it under the terms of version 2 of the GNU General Public License as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/dmaengine.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/of_dma.h>
16 #include <linux/of_platform.h>
17 #include <linux/platform_device.h>
18 #include <linux/shdma-base.h>
19
20 #define to_shdma_chan(c) container_of(c, struct shdma_chan, dma_chan)
21
shdma_of_xlate(struct of_phandle_args * dma_spec,struct of_dma * ofdma)22 static struct dma_chan *shdma_of_xlate(struct of_phandle_args *dma_spec,
23 struct of_dma *ofdma)
24 {
25 u32 id = dma_spec->args[0];
26 dma_cap_mask_t mask;
27 struct dma_chan *chan;
28
29 if (dma_spec->args_count != 1)
30 return NULL;
31
32 dma_cap_zero(mask);
33 /* Only slave DMA channels can be allocated via DT */
34 dma_cap_set(DMA_SLAVE, mask);
35
36 chan = dma_request_channel(mask, shdma_chan_filter,
37 (void *)(uintptr_t)id);
38 if (chan)
39 to_shdma_chan(chan)->hw_req = id;
40
41 return chan;
42 }
43
shdma_of_probe(struct platform_device * pdev)44 static int shdma_of_probe(struct platform_device *pdev)
45 {
46 const struct of_dev_auxdata *lookup = dev_get_platdata(&pdev->dev);
47 int ret;
48
49 ret = of_dma_controller_register(pdev->dev.of_node,
50 shdma_of_xlate, pdev);
51 if (ret < 0)
52 return ret;
53
54 ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
55 if (ret < 0)
56 of_dma_controller_free(pdev->dev.of_node);
57
58 return ret;
59 }
60
61 static const struct of_device_id shdma_of_match[] = {
62 { .compatible = "renesas,shdma-mux", },
63 { }
64 };
65 MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
66
67 static struct platform_driver shdma_of = {
68 .driver = {
69 .name = "shdma-of",
70 .of_match_table = shdma_of_match,
71 },
72 .probe = shdma_of_probe,
73 };
74
75 module_platform_driver(shdma_of);
76
77 MODULE_LICENSE("GPL v2");
78 MODULE_DESCRIPTION("SH-DMA driver DT glue");
79 MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
80