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