ASoC: wcd-dsp-utils: Add utilities for wcd dsp

wcd_dsp_utils adds utilities that will be used by the
wcd dsp manager driver. Add helper functions to parse
WDSP image and provide list of segments to be loaded
to memory.

CRs-Fixed: 1049012
Change-Id: I2b1464c2a035a039440e6d3e5122ad3f90da4d1e
Signed-off-by: Bhalchandra Gajare <gajare@codeaurora.org>

3 files changed, 273 insertions, 0 deletions

diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
index ed2e49ddf432..6ca8559a4f2f 100644
--- a/sound/soc/codecs/Makefile
+++ b/sound/soc/codecs/Makefile
@@ -143,6 +143,7 @@ snd-soc-wcd-mbhc-objs := wcd-mbhc-v2.o
 snd-soc-msm8952-wcd-objs := msm8x16-wcd.o msm8x16-wcd-tables.o
 snd-soc-wsa881x-analog-objs := wsa881x-analog.o wsa881x-tables-analog.o
 snd-soc-wsa881x-analog-objs += wsa881x-regmap-analog.o wsa881x-irq.o
+snd-soc-wcd-dsp-utils-objs := wcd-dsp-utils.o
 snd-soc-wl1273-objs := wl1273.o
 snd-soc-wm-adsp-objs := wm_adsp.o
 snd-soc-wm0010-objs := wm0010.o
diff --git a/sound/soc/codecs/wcd-dsp-utils.c b/sound/soc/codecs/wcd-dsp-utils.c
new file mode 100644
index 000000000000..1f048917a6c8
--- /dev/null
+++ b/sound/soc/codecs/wcd-dsp-utils.c
@@ -0,0 +1,221 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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/device.h>
+#include <linux/err.h>
+#include <linux/firmware.h>
+#include <linux/elf.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include "wcd-dsp-utils.h"
+
+static bool wdsp_is_valid_elf_hdr(const struct elf32_hdr *ehdr,
+				  size_t fw_size)
+{
+	if (fw_size < sizeof(*ehdr)) {
+		pr_err("%s: Firmware too small\n", __func__);
+		goto elf_check_fail;
+	}
+
+	if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG) != 0) {
+		pr_err("%s: Not an ELF file\n", __func__);
+		goto elf_check_fail;
+	}
+
+	if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN) {
+		pr_err("%s: Not an executable image\n", __func__);
+		goto elf_check_fail;
+	}
+
+	if (ehdr->e_phnum == 0) {
+		pr_err("%s: no segments to load\n", __func__);
+		goto elf_check_fail;
+	}
+
+	if (sizeof(struct elf32_phdr) * ehdr->e_phnum +
+	    sizeof(struct elf32_hdr) > fw_size) {
+		pr_err("%s: Too small MDT file\n", __func__);
+		goto elf_check_fail;
+	}
+
+	return true;
+
+elf_check_fail:
+	return false;
+}
+
+static int wdsp_add_segment_to_list(struct device *dev,
+				    const char *img_fname,
+				    const struct elf32_phdr *phdr,
+				    int phdr_idx,
+				    struct list_head *seg_list)
+{
+	struct wdsp_img_segment *seg;
+	int ret = 0;
+
+	/* Do not load segments with zero size */
+	if (phdr->p_filesz == 0 || phdr->p_memsz == 0)
+		goto done;
+
+	seg = kzalloc(sizeof(*seg), GFP_KERNEL);
+	if (!seg) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	snprintf(seg->split_fname, sizeof(seg->split_fname),
+		 "%s.b%02d", img_fname, phdr_idx);
+	ret = request_firmware(&seg->split_fw, seg->split_fname, dev);
+	if (IS_ERR_VALUE(ret)) {
+		dev_err(dev, "%s: firmware %s not found\n",
+			__func__, seg->split_fname);
+		goto bad_seg;
+	}
+
+	seg->load_addr = phdr->p_paddr;
+	seg->size = phdr->p_filesz;
+	seg->data = (u8 *) seg->split_fw->data;
+
+	list_add_tail(&seg->list, seg_list);
+done:
+	return ret;
+bad_seg:
+	kfree(seg);
+	return ret;
+}
+
+/*
+ * wdsp_flush_segment_list: Flush the list of segments
+ * @seg_list: List of segments to be flushed
+ * This API will traverse through the list of segments provided in
+ * seg_list, release the firmware for each segment and delete the
+ * segment from the list.
+ */
+void wdsp_flush_segment_list(struct list_head *seg_list)
+{
+	struct wdsp_img_segment *seg, *next;
+
+	list_for_each_entry_safe(seg, next, seg_list, list) {
+		release_firmware(seg->split_fw);
+		list_del(&seg->list);
+		kfree(seg);
+	}
+}
+EXPORT_SYMBOL(wdsp_flush_segment_list);
+
+/*
+ * wdsp_get_segment_list: Get the list of requested segments
+ * @dev: struct device pointer of caller
+ * @img_fname: Image name for the mdt and split firmware files
+ * @segment_type: Requested segment type, should be either
+ *		  WDSP_ELF_FLAG_RE or WDSP_ELF_FLAG_WRITE
+ * @seg_list: An initialized head for list of segmented to be returned
+ * @entry_point: Pointer to return the entry point of the image
+ * This API will parse the mdt file for img_fname and create
+ * an struct wdsp_img_segment for each segment that matches segment_type
+ * and add this structure to list pointed by seg_list
+ */
+int wdsp_get_segment_list(struct device *dev,
+			  const char *img_fname,
+			  unsigned int segment_type,
+			  struct list_head *seg_list,
+			  u32 *entry_point)
+{
+	const struct firmware *fw;
+	const struct elf32_hdr *ehdr;
+	const struct elf32_phdr *phdr;
+	const u8 *elf_ptr;
+	char mdt_name[WDSP_IMG_NAME_LEN_MAX];
+	int ret, phdr_idx;
+	bool segment_match;
+
+	if (!dev) {
+		ret = -EINVAL;
+		pr_err("%s: Invalid device handle\n", __func__);
+		goto done;
+	}
+
+	if (!img_fname || !seg_list || !entry_point) {
+		ret = -EINVAL;
+		dev_err(dev, "%s: Invalid input params\n",
+			__func__);
+		goto done;
+	}
+
+	if (segment_type != WDSP_ELF_FLAG_RE &&
+	    segment_type != WDSP_ELF_FLAG_WRITE) {
+		dev_err(dev, "%s: Invalid request for segment_type %d\n",
+			__func__, segment_type);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	snprintf(mdt_name, sizeof(mdt_name), "%s.mdt", img_fname);
+	ret = request_firmware(&fw, mdt_name, dev);
+	if (IS_ERR_VALUE(ret)) {
+		dev_err(dev, "%s: firmware %s not found\n",
+			__func__, mdt_name);
+		goto done;
+	}
+
+	ehdr = (struct elf32_hdr *) fw->data;
+	*entry_point = ehdr->e_entry;
+	if (!wdsp_is_valid_elf_hdr(ehdr, fw->size)) {
+		dev_err(dev, "%s: fw mdt %s is invalid\n",
+			__func__, mdt_name);
+		ret = -EINVAL;
+		goto bad_elf;
+	}
+
+	elf_ptr = fw->data + sizeof(*ehdr);
+	for (phdr_idx = 0; phdr_idx < ehdr->e_phnum; phdr_idx++) {
+		phdr = (struct elf32_phdr *) elf_ptr;
+		segment_match = false;
+
+		switch (segment_type) {
+		case WDSP_ELF_FLAG_RE:
+			/*
+			 * Flag can be READ or EXECUTE or both but
+			 * WRITE flag should not be set.
+			 */
+			if ((phdr->p_flags & segment_type) &&
+			    !(phdr->p_flags & WDSP_ELF_FLAG_WRITE))
+				segment_match = true;
+			break;
+		case WDSP_ELF_FLAG_WRITE:
+			/*
+			 * If WRITE flag is set, other flags do not
+			 * matter.
+			 */
+			if (phdr->p_flags & segment_type)
+				segment_match = true;
+			break;
+		}
+
+		if (segment_match) {
+			ret = wdsp_add_segment_to_list(dev, img_fname, phdr,
+						       phdr_idx, seg_list);
+			if (IS_ERR_VALUE(ret)) {
+				wdsp_flush_segment_list(seg_list);
+				goto bad_elf;
+			}
+		}
+		elf_ptr = elf_ptr + sizeof(*phdr);
+	}
+
+bad_elf:
+	release_firmware(fw);
+done:
+	return ret;
+}
+EXPORT_SYMBOL(wdsp_get_segment_list);
diff --git a/sound/soc/codecs/wcd-dsp-utils.h b/sound/soc/codecs/wcd-dsp-utils.h
new file mode 100644
index 000000000000..81842f77260e
--- /dev/null
+++ b/sound/soc/codecs/wcd-dsp-utils.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only 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.
+ */
+
+#ifndef __WCD_DSP_UTILS_H__
+#define __WCD_DSP_UTILS_H__
+
+#define WDSP_IMG_NAME_LEN_MAX    64
+
+#define WDSP_ELF_FLAG_EXECUTE    (1 << 0)
+#define WDSP_ELF_FLAG_WRITE      (1 << 1)
+#define WDSP_ELF_FLAG_READ       (1 << 2)
+
+#define WDSP_ELF_FLAG_RE (WDSP_ELF_FLAG_READ | WDSP_ELF_FLAG_EXECUTE)
+
+struct wdsp_img_segment {
+
+	/* Firmware for the slit image */
+	const struct firmware *split_fw;
+
+	/* Name of the split firmware file */
+	char split_fname[WDSP_IMG_NAME_LEN_MAX];
+
+	/* Address where the segment is to be loaded */
+	u32 load_addr;
+
+	/* Buffer to hold the data to be loaded */
+	u8 *data;
+
+	/* Size of the data to be loaded */
+	size_t size;
+
+	/* List node pointing to next segment */
+	struct list_head list;
+};
+
+int wdsp_get_segment_list(struct device *, const char *,
+			  unsigned int, struct list_head *,
+			  u32 *);
+void wdsp_flush_segment_list(struct list_head *);
+
+#endif /* __WCD_DSP_UTILS_H__ */