ASoC: SOF: OF: Add fw_path and tplg_path parameters

This allows specifying an alternate path for SOF firmware or
SOF topology.

This is particularly useful for i.MX when running Linux vs Android.
Signed-off-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Link: https://lore.kernel.org/r/20211005071949.1277613-1-daniel.baluta@oss.nxp.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/sof-of-dev.c

@@ -7,12 +7,21 @@
 
 #include <linux/firmware.h>
 #include <linux/module.h>
+#include <linux/moduleparam.h>
 #include <linux/pm_runtime.h>
 #include <sound/sof.h>
 
 #include "ops.h"
 #include "imx/imx-ops.h"
 
+static char *fw_path;
+module_param(fw_path, charp, 0444);
+MODULE_PARM_DESC(fw_path, "alternate path for SOF firmware.");
+
+static char *tplg_path;
+module_param(tplg_path, charp, 0444);
+MODULE_PARM_DESC(tplg_path, "alternate path for SOF topology.");
+
 /* platform specific devices */
 #if IS_ENABLED(CONFIG_SND_SOC_SOF_IMX8)
 static struct sof_dev_desc sof_of_imx8qxp_desc = {
@@ -87,9 +96,15 @@ static int sof_of_probe(struct platform_device *pdev)
 	sof_pdata->dev = &pdev->dev;
 	sof_pdata->fw_filename = desc->default_fw_filename;
 
-	/* TODO: read alternate fw and tplg filenames from DT */
-	sof_pdata->fw_filename_prefix = sof_pdata->desc->default_fw_path;
-	sof_pdata->tplg_filename_prefix = sof_pdata->desc->default_tplg_path;
+	if (fw_path)
+		sof_pdata->fw_filename_prefix = fw_path;
+	else
+		sof_pdata->fw_filename_prefix = sof_pdata->desc->default_fw_path;
+
+	if (tplg_path)
+		sof_pdata->tplg_filename_prefix = tplg_path;
+	else
+		sof_pdata->tplg_filename_prefix = sof_pdata->desc->default_tplg_path;
 
 	/* set callback to be called on successful device probe to enable runtime_pm */
 	sof_pdata->sof_probe_complete = sof_of_probe_complete;