ASoC: Intel: Skylake: Add strip extended manifest utility

[mirror_ubuntu-eoan-kernel.git] / sound / soc / intel / skylake / skl-sst-utils.c

/*
 *  skl-sst-utils.c - SKL sst utils functions
 *
 *  Copyright (C) 2016 Intel Corp
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/firmware.h>
#include "skl-sst-dsp.h"

/* FW Extended Manifest Header id = $AE1 */
#define SKL_EXT_MANIFEST_HEADER_MAGIC   0x31454124

struct skl_ext_manifest_hdr {
	u32 id;
	u32 len;
	u16 version_major;
	u16 version_minor;
	u32 entries;
};

/*
 * some firmware binary contains some extended manifest. This needs
 * to be stripped in that case before we load and use that image.
 *
 * So check for magic header, if found strip the header
 */
int skl_dsp_strip_extended_manifest(struct firmware *fw)
{
	struct skl_ext_manifest_hdr *hdr;

	/* check if fw file is greater than header we are looking */
	if (fw->size < sizeof(hdr)) {
		pr_err("%s: Firmware file small, no hdr\n", __func__);
		return -EINVAL;
	}

	hdr = (struct skl_ext_manifest_hdr *)fw->data;

	if (hdr->id == SKL_EXT_MANIFEST_HEADER_MAGIC) {
		fw->size -= hdr->len;
		fw->data += hdr->len;
	}

	return 0;
}