// 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.%pOFn", (unsigned long long) res.start, dma_channel_np); 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");