tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 ret = of_dma_controller_register(pdev->dev.of_node,
49 shdma_of_xlate, pdev);
50 if (ret < 0)
51 return ret;
52
53 ret = of_platform_populate(pdev->dev.of_node, NULL, lookup, &pdev->dev);
54 if (ret < 0)
55 of_dma_controller_free(pdev->dev.of_node);
56
57 return ret;
58}
59
60static const struct of_device_id shdma_of_match[] = {
61 { .compatible = "renesas,shdma-mux", },
62 { }
63};
64MODULE_DEVICE_TABLE(of, sh_dmae_of_match);
65
66static struct platform_driver shdma_of = {
67 .driver = {
68 .owner = THIS_MODULE,
69 .name = "shdma-of",
70 .of_match_table = shdma_of_match,
71 },
72 .probe = shdma_of_probe,
73};
74
75module_platform_driver(shdma_of);
76
77MODULE_LICENSE("GPL v2");
78MODULE_DESCRIPTION("SH-DMA driver DT glue");
79MODULE_AUTHOR("Guennadi Liakhovetski <g.liakhovetski@gmx.de>");