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// SPDX-License-Identifier: GPL-2.0
//
// Freescale ALSA SoC Machine driver utility
//
// Author: Timur Tabi <timur@freescale.com>
//
// Copyright 2010 Freescale Semiconductor, Inc.
#include <linux/module.h>
#include <linux/of_address.h>
#include <sound/soc.h>
#include "fsl_utils.h"
/**
* fsl_asoc_get_dma_channel - determine the dma channel for a SSI node
*
* @ssi_np: pointer to the SSI device tree node
* @name: name of the phandle pointing to the dma channel
* @dai: ASoC DAI link pointer to be filled with platform_name
* @dma_channel_id: dma channel id to be returned
* @dma_id: dma id to be returned
*
* This function determines the dma and channel id for given SSI node. It
* also discovers the platform_name for the ASoC DAI link.
*/
int fsl_asoc_get_dma_channel(struct device_node *ssi_np,
const char *name,
struct snd_soc_dai_link *dai,
unsigned int *dma_channel_id,
unsigned int *dma_id)
{
struct resource res;
struct device_node *dma_channel_np, *dma_np;
const __be32 *iprop;
int ret;
dma_channel_np = of_parse_phandle(ssi_np, name, 0);
if (!dma_channel_np)
return -EINVAL;
if (!of_device_is_compatible(dma_channel_np, "fsl,ssi-dma-channel")) {
of_node_put(dma_channel_np);
return -EINVAL;
}
/* Determine the dev_name for the device_node. This code mimics the
* behavior of of_device_make_bus_id(). We need this because ASoC uses
* the dev_name() of the device to match the platform (DMA) device with
* the CPU (SSI) device. It's all ugly and hackish, but it works (for
* now).
*
* dai->platform name should already point to an allocated buffer.
*/
ret = of_address_to_resource(dma_channel_np, 0, &res);
if (ret) {
of_node_put(dma_channel_np);
return ret;
}
snprintf((char *)dai->platform_name, DAI_NAME_SIZE, "%llx.%s",
(unsigned long long) res.start, dma_channel_np->name);
iprop = of_get_property(dma_channel_np, "cell-index", NULL);
if (!iprop) {
of_node_put(dma_channel_np);
return -EINVAL;
}
*dma_channel_id = be32_to_cpup(iprop);
dma_np = of_get_parent(dma_channel_np);
iprop = of_get_property(dma_np, "cell-index", NULL);
if (!iprop) {
of_node_put(dma_np);
return -EINVAL;
}
*dma_id = be32_to_cpup(iprop);
of_node_put(dma_np);
of_node_put(dma_channel_np);
return 0;
}
EXPORT_SYMBOL(fsl_asoc_get_dma_channel);
MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
MODULE_DESCRIPTION("Freescale ASoC utility code");
MODULE_LICENSE("GPL v2");
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