fsl_utils.c

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#include <linux/module.h>
#include <linux/of_address.h>
#include <sound/soc.h>

#include "fsl_utils.h"

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 u32 *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 <[email protected]>");
MODULE_DESCRIPTION("Freescale ASoC utility code");
MODULE_LICENSE("GPL v2");