[PATCHv3 2/5] FWU: mtd: Add helper functions for accessing FWU metadata

[Jassi Brar <jassisinghbrar@gmail.com>]

From: Sughosh Ganu <sughosh.ganu@linaro.org>

Add helper functions needed for accessing the FWU metadata which
contains information on the updatable images.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
---
 include/fwu.h             |  27 ++++++
 lib/fwu_updates/Makefile  |   1 +
 lib/fwu_updates/fwu_mtd.c | 172 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 200 insertions(+)
 create mode 100644 lib/fwu_updates/fwu_mtd.c

diff --git a/include/fwu.h b/include/fwu.h
index ea25aca2cd..2edfa72caf 100644
--- a/include/fwu.h
+++ b/include/fwu.h
@@ -8,6 +8,7 @@
 
 #include <blk.h>
 #include <efi.h>
+#include <mtd.h>
 
 #include <linux/types.h>
 
@@ -251,4 +252,30 @@ u8 fwu_empty_capsule_checks_pass(void);
  */
 int fwu_trial_state_ctr_start(void);
 
+/**
+ * fwu_gen_alt_info_from_mtd() - Parse dfu_alt_info from metadata in mtd
+ * @buf: Buffer into which the dfu_alt_info is filled
+ * @len: Maximum charaters that can be written in buf
+ * @mtd: Pointer to underlying MTD device
+ *
+ * Parse dfu_alt_info from metadata in mtd. Used for setting the env.
+ *
+ * Return: 0 if OK, -ve on error
+ *
+ */
+int fwu_gen_alt_info_from_mtd(char *buf, size_t len, struct mtd_info *mtd);
+
+/**
+ * fwu_mtd_get_alt_num() - Mapping of fwu_plat_get_alt_num for MTD device
+ * @image_guid: Image GUID for which DFU alt number needs to be retrieved
+ * @alt_num: Pointer to the alt_num
+ * @mtd_dev: Name of mtd device instance
+ *
+ * To map fwu_plat_get_alt_num onto mtd based metadata implementation.
+ *
+ * Return: 0 if OK, -ve on error
+ *
+ */
+int fwu_mtd_get_alt_num(efi_guid_t *image_id, u8 *alt_num, const char *mtd_dev);
+
 #endif /* _FWU_H_ */
diff --git a/lib/fwu_updates/Makefile b/lib/fwu_updates/Makefile
index 1993088e5b..c9e3c06b48 100644
--- a/lib/fwu_updates/Makefile
+++ b/lib/fwu_updates/Makefile
@@ -5,3 +5,4 @@
 
 obj-$(CONFIG_FWU_MULTI_BANK_UPDATE) += fwu.o
 obj-$(CONFIG_FWU_MDATA_GPT_BLK) += fwu_gpt.o
+obj-$(CONFIG_FWU_MDATA_MTD) += fwu_mtd.o
diff --git a/lib/fwu_updates/fwu_mtd.c b/lib/fwu_updates/fwu_mtd.c
new file mode 100644
index 0000000000..1895b8fab3
--- /dev/null
+++ b/lib/fwu_updates/fwu_mtd.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023, Linaro Limited
+ */
+
+#include <dm.h>
+#include <dfu.h>
+#include <fwu.h>
+#include <fwu_mdata.h>
+#include <log.h>
+#include <malloc.h>
+#include <mtd.h>
+#include <uuid.h>
+#include <vsprintf.h>
+
+#include <dm/ofnode.h>
+
+int fwu_mtd_get_alt_num(efi_guid_t *image_id, u8 *alt_num,
+			const char *mtd_dev)
+{
+	int i, nalt;
+	int ret = -1;
+	struct mtd_info *mtd;
+	struct dfu_entity *dfu;
+	ofnode node, parts_node;
+	fdt_addr_t offset, size;
+	char uuidbuf[UUID_STR_LEN + 1];
+
+	mtd_probe_devices();
+	mtd = get_mtd_device_nm(mtd_dev);
+
+	/* Find partition node under given MTD device. */
+	parts_node = ofnode_by_compatible(mtd_get_ofnode(mtd),
+					  "fixed-partitions");
+
+	uuid_bin_to_str(image_id->b, uuidbuf, UUID_STR_FORMAT_STD);
+	node = ofnode_by_prop_value(parts_node, "uuid", uuidbuf,
+				    sizeof(uuidbuf));
+	if (!ofnode_valid(node)) {
+		log_warning("Warning: Failed to find partition by image UUID\n");
+		return -ENOENT;
+	}
+
+	offset = ofnode_get_addr_size_index_notrans(node, 0, &size);
+	if (offset == FDT_ADDR_T_NONE || !size)
+		return -ENOENT;
+
+	dfu_init_env_entities(NULL, NULL);
+
+	nalt = 0;
+	list_for_each_entry(dfu, &dfu_list, list)
+		nalt++;
+
+	if (!nalt) {
+		log_warning("No entities in dfu_alt_info\n");
+		dfu_free_entities();
+		return -ENOENT;
+	}
+
+	for (i = 0; i < nalt; i++) {
+		dfu = dfu_get_entity(i);
+
+		/* Only MTD RAW access */
+		if (!dfu || dfu->dev_type != DFU_DEV_MTD ||
+			dfu->layout != DFU_RAW_ADDR ||
+			dfu->data.mtd.start != offset ||
+			dfu->data.mtd.size != size)
+			continue;
+
+		*alt_num = dfu->alt;
+		ret = 0;
+		break;
+	}
+
+	dfu_free_entities();
+
+	return ret;
+}
+
+static int gen_image_alt_info(char *buf, size_t len, int sidx,
+		       struct fwu_image_entry *img, struct mtd_info *mtd)
+{
+	int i;
+	const char *suuid;
+	ofnode node, parts_node;
+	char uuidbuf[UUID_STR_LEN + 1];
+	char *p = buf, *end = buf + len;
+
+	/* Find partition node under given MTD device. */
+	parts_node = ofnode_by_compatible(mtd_get_ofnode(mtd),
+					  "fixed-partitions");
+	if (!ofnode_valid(parts_node))
+		return -ENOENT;
+
+	/* Check the media UUID if exist. */
+	suuid = ofnode_read_string(parts_node, "uuid");
+	if (suuid) {
+		log_debug("Got location uuid %s\n", suuid);
+		uuid_bin_to_str(img->location_uuid.b, uuidbuf, UUID_STR_FORMAT_STD);
+		if (strcasecmp(suuid, uuidbuf))
+			log_warning("Warning: Location UUID does not match!\n");
+	}
+
+	p += snprintf(p, end - p, "mtd %s", mtd->name);
+	if (end < p) {
+		log_err("%s:%d Run out of buffer\n", __func__, __LINE__);
+		return -E2BIG;
+	}
+
+	/*
+	 * List the image banks in the FWU mdata and search the corresponding
+	 * partition based on partition's uuid.
+	 */
+	for (i = 0; i < CONFIG_FWU_NUM_BANKS; i++) {
+		struct fwu_image_bank_info *bank;
+		fdt_addr_t offset, size;
+
+		/* Query a partition by image UUID */
+		bank = &img->img_bank_info[i];
+		uuid_bin_to_str(bank->image_uuid.b, uuidbuf, UUID_STR_FORMAT_STD);
+		node = ofnode_by_prop_value(parts_node, "uuid", uuidbuf,
+					    sizeof(uuidbuf));
+		if (!ofnode_valid(node)) {
+			log_err("Failed to find partition by image UUID\n");
+			break;
+		}
+
+		offset = ofnode_get_addr_size_index_notrans(node, 0, &size);
+		if (offset == FDT_ADDR_T_NONE || !size)
+			break;
+
+		p += snprintf(p, end - p, "%sbank%d raw %lx %lx",
+			      i == 0 ? "=" : ";", i, (unsigned long)offset,
+			      (unsigned long)size);
+		if (end < p) {
+			log_err("%s:%d Run out of buffer\n", __func__, __LINE__);
+			return -E2BIG;
+		}
+	}
+
+	if (i == CONFIG_FWU_NUM_BANKS)
+		return 0;
+
+	return -ENOENT;
+}
+
+int fwu_gen_alt_info_from_mtd(char *buf, size_t len, struct mtd_info *mtd)
+{
+	struct fwu_mdata mdata;
+	int i, l, ret;
+
+	ret = fwu_get_mdata(&mdata);
+	if (ret < 0) {
+		log_debug("Failed to get the FWU mdata.\n");
+		return ret;
+	}
+
+	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
+		ret = gen_image_alt_info(buf, len, i * CONFIG_FWU_NUM_BANKS,
+					 &mdata.img_entry[i], mtd);
+		if (ret)
+			break;
+		l = strlen(buf);
+		/* Replace the last ';' with '&' if there is another image. */
+		if (i != CONFIG_FWU_NUM_IMAGES_PER_BANK - 1 && l)
+			buf[l - 1] = '&';
+		len -= l;
+		buf += l;
+	}
+
+	return ret;
+}
-- 
2.34.1