shdma-of.c revision d4adcc0160404c3237fe6ffa09dd2dd039dd3975 
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
22static 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, (void *)id);
37	if (chan)
38		to_shdma_chan(chan)->hw_req = id;
39
40	return chan;
41}
42
43static int shdma_of_probe(struct platform_device *pdev)
44{
45	const struct of_dev_auxdata *lookup = dev_get_platdata(&pdev->dev);
46	int ret;
47
48	if (!lookup)
49		return -EINVAL;
50
51	ret = of_dma_controller_register(pdev->dev.of_node,
52					 shdma_of_xlate, pdev);
53	if (ret < 0)
54		return ret;
55
56	ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
57	if (ret < 0)
58		of_dma_controller_free(pdev->dev.of_node);
59
60	return ret;
61}
62
63static const struct of_device_id shdma_of_match[] = {
64	{ .compatible = "renesas,shdma-mux", },
65	{ }
66};
67MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
68
69static struct platform_driver shdma_of = {
70	.driver		= {
71		.owner	= THIS_MODULE,
72		.name	= "shdma-of",
73		.of_match_table = shdma_of_match,
74	},
75	.probe		= shdma_of_probe,
76};
77
78module_platform_driver(shdma_of);
79
80MODULE_LICENSE("GPL v2");
81MODULE_DESCRIPTION("SH-DMA driver DT glue");
82MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");
83