cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fsl_utils.c (2506B)

      1// SPDX-License-Identifier: GPL-2.0
      2//
      3// Freescale ALSA SoC Machine driver utility
      4//
      5// Author: Timur Tabi <timur@freescale.com>
      6//
      7// Copyright 2010 Freescale Semiconductor, Inc.
      8
      9#include <linux/module.h>
     10#include <linux/of_address.h>
     11#include <sound/soc.h>
     12
     13#include "fsl_utils.h"
     14
     15/**
     16 * fsl_asoc_get_dma_channel - determine the dma channel for a SSI node
     17 *
     18 * @ssi_np: pointer to the SSI device tree node
     19 * @name: name of the phandle pointing to the dma channel
     20 * @dai: ASoC DAI link pointer to be filled with platform_name
     21 * @dma_channel_id: dma channel id to be returned
     22 * @dma_id: dma id to be returned
     23 *
     24 * This function determines the dma and channel id for given SSI node.  It
     25 * also discovers the platform_name for the ASoC DAI link.
     26 */
     27int fsl_asoc_get_dma_channel(struct device_node *ssi_np,
     28			     const char *name,
     29			     struct snd_soc_dai_link *dai,
     30			     unsigned int *dma_channel_id,
     31			     unsigned int *dma_id)
     32{
     33	struct resource res;
     34	struct device_node *dma_channel_np, *dma_np;
     35	const __be32 *iprop;
     36	int ret;
     37
     38	dma_channel_np = of_parse_phandle(ssi_np, name, 0);
     39	if (!dma_channel_np)
     40		return -EINVAL;
     41
     42	if (!of_device_is_compatible(dma_channel_np, "fsl,ssi-dma-channel")) {
     43		of_node_put(dma_channel_np);
     44		return -EINVAL;
     45	}
     46
     47	/* Determine the dev_name for the device_node.  This code mimics the
     48	 * behavior of of_device_make_bus_id(). We need this because ASoC uses
     49	 * the dev_name() of the device to match the platform (DMA) device with
     50	 * the CPU (SSI) device.  It's all ugly and hackish, but it works (for
     51	 * now).
     52	 *
     53	 * dai->platform name should already point to an allocated buffer.
     54	 */
     55	ret = of_address_to_resource(dma_channel_np, 0, &res);
     56	if (ret) {
     57		of_node_put(dma_channel_np);
     58		return ret;
     59	}
     60	snprintf((char *)dai->platforms->name, DAI_NAME_SIZE, "%llx.%pOFn",
     61		 (unsigned long long) res.start, dma_channel_np);
     62
     63	iprop = of_get_property(dma_channel_np, "cell-index", NULL);
     64	if (!iprop) {
     65		of_node_put(dma_channel_np);
     66		return -EINVAL;
     67	}
     68	*dma_channel_id = be32_to_cpup(iprop);
     69
     70	dma_np = of_get_parent(dma_channel_np);
     71	iprop = of_get_property(dma_np, "cell-index", NULL);
     72	if (!iprop) {
     73		of_node_put(dma_np);
     74		of_node_put(dma_channel_np);
     75		return -EINVAL;
     76	}
     77	*dma_id = be32_to_cpup(iprop);
     78
     79	of_node_put(dma_np);
     80	of_node_put(dma_channel_np);
     81
     82	return 0;
     83}
     84EXPORT_SYMBOL(fsl_asoc_get_dma_channel);
     85
     86MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
     87MODULE_DESCRIPTION("Freescale ASoC utility code");
     88MODULE_LICENSE("GPL v2");