1 files changed, 91 insertions, 0 deletions

diff --git a/sound/soc/fsl/fsl_utils.c b/sound/soc/fsl/fsl_utils.c
new file mode 100644
index 000000000000..b9e42b503a37
--- /dev/null
+++ b/sound/soc/fsl/fsl_utils.c
@@ -0,0 +1,91 @@
+/**
+ * Freescale ALSA SoC Machine driver utility
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * Copyright 2010 Freescale Semiconductor, Inc.
+ *
+ * This file is licensed under the terms of the GNU General Public License
+ * version 2.  This program is licensed "as is" without any warranty of any
+ * kind, whether express or implied.
+ */
+
+#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 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 <timur@freescale.com>");
+MODULE_DESCRIPTION("Freescale ASoC utility code");
+MODULE_LICENSE("GPL v2");