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1 | /** |
2 | * Freescale ALSA SoC Machine driver utility | |
3 | * | |
4 | * Author: Timur Tabi <timur@freescale.com> | |
5 | * | |
6 | * Copyright 2010 Freescale Semiconductor, Inc. | |
7 | * | |
8 | * This file is licensed under the terms of the GNU General Public License | |
9 | * version 2. This program is licensed "as is" without any warranty of any | |
10 | * kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | #include <linux/module.h> | |
14 | #include <linux/of_address.h> | |
60aae8da SG |
15 | #include <sound/soc.h> |
16 | ||
17 | #include "fsl_utils.h" | |
18 | ||
60aae8da SG |
19 | /** |
20 | * fsl_asoc_get_dma_channel - determine the dma channel for a SSI node | |
21 | * | |
22 | * @ssi_np: pointer to the SSI device tree node | |
23 | * @name: name of the phandle pointing to the dma channel | |
24 | * @dai: ASoC DAI link pointer to be filled with platform_name | |
25 | * @dma_channel_id: dma channel id to be returned | |
26 | * @dma_id: dma id to be returned | |
27 | * | |
28 | * This function determines the dma and channel id for given SSI node. It | |
29 | * also discovers the platform_name for the ASoC DAI link. | |
30 | */ | |
31 | int fsl_asoc_get_dma_channel(struct device_node *ssi_np, | |
32 | const char *name, | |
33 | struct snd_soc_dai_link *dai, | |
34 | unsigned int *dma_channel_id, | |
35 | unsigned int *dma_id) | |
36 | { | |
37 | struct resource res; | |
38 | struct device_node *dma_channel_np, *dma_np; | |
39 | const u32 *iprop; | |
40 | int ret; | |
41 | ||
42 | dma_channel_np = of_parse_phandle(ssi_np, name, 0); | |
43 | if (!dma_channel_np) | |
44 | return -EINVAL; | |
45 | ||
46 | if (!of_device_is_compatible(dma_channel_np, "fsl,ssi-dma-channel")) { | |
47 | of_node_put(dma_channel_np); | |
48 | return -EINVAL; | |
49 | } | |
50 | ||
51 | /* Determine the dev_name for the device_node. This code mimics the | |
52 | * behavior of of_device_make_bus_id(). We need this because ASoC uses | |
53 | * the dev_name() of the device to match the platform (DMA) device with | |
54 | * the CPU (SSI) device. It's all ugly and hackish, but it works (for | |
55 | * now). | |
56 | * | |
57 | * dai->platform name should already point to an allocated buffer. | |
58 | */ | |
59 | ret = of_address_to_resource(dma_channel_np, 0, &res); | |
60 | if (ret) { | |
61 | of_node_put(dma_channel_np); | |
62 | return ret; | |
63 | } | |
64 | snprintf((char *)dai->platform_name, DAI_NAME_SIZE, "%llx.%s", | |
65 | (unsigned long long) res.start, dma_channel_np->name); | |
66 | ||
67 | iprop = of_get_property(dma_channel_np, "cell-index", NULL); | |
68 | if (!iprop) { | |
69 | of_node_put(dma_channel_np); | |
70 | return -EINVAL; | |
71 | } | |
72 | *dma_channel_id = be32_to_cpup(iprop); | |
73 | ||
74 | dma_np = of_get_parent(dma_channel_np); | |
75 | iprop = of_get_property(dma_np, "cell-index", NULL); | |
76 | if (!iprop) { | |
77 | of_node_put(dma_np); | |
78 | return -EINVAL; | |
79 | } | |
80 | *dma_id = be32_to_cpup(iprop); | |
81 | ||
82 | of_node_put(dma_np); | |
83 | of_node_put(dma_channel_np); | |
84 | ||
85 | return 0; | |
86 | } | |
87 | EXPORT_SYMBOL(fsl_asoc_get_dma_channel); | |
88 | ||
89 | MODULE_AUTHOR("Timur Tabi <timur@freescale.com>"); | |
90 | MODULE_DESCRIPTION("Freescale ASoC utility code"); | |
91 | MODULE_LICENSE("GPL v2"); |