subsys: storage: Add flash_map abstraction module

Introduce flas_map module is abstraction over flash memory and its
driver for using flash memories along with description of
available flash areas.
Module provides simple API for write/read/erase and so one.

Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>

subsys/storage/CMakeLists.txt

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+add_subdirectory_ifdef(CONFIG_FLASH_MAP  flash_map)

subsys/storage/Kconfig

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+# Kconfig - Subsystem configuration options
+#
+# Copyright (c) 2018 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+
+menu "Storage"
+
+source "subsys/storage/flash_map/Kconfig"
+
+endmenu

subsys/storage/flash_map/CMakeLists.txt

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+zephyr_sources(flash_map.c)
+zephyr_sources_ifndef(CONFIG_FLASH_MAP_CUSTOM flash_map_default.c)
+

subsys/storage/flash_map/Kconfig

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+# Kconfig - Flash map abstraction module
+#
+# Copyright (c) 2017 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+#
+# Flash map
+#
+
+menuconfig FLASH_MAP
+	bool
+	prompt "Flash map abstraction module"
+	default n
+	depends on FLASH
+	help
+	  Enable support of flash map abstraction.
+
+config FLASH_MAP_CUSTOM
+	bool
+	prompt "Custom flash map description"
+	default n
+	depends on FLASH_MAP
+	help
+	  This option enables custom flash map description.
+	  User must provide such a description in place of default on
+	  if had enabled this option.

subsys/storage/flash_map/flash_map.c

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+/*
+ * Copyright (c) 2017 Nordic Semiconductor ASA
+ * Copyright (c) 2015 Runtime Inc
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/types.h>
+#include <stddef.h>
+#include <sys/types.h>
+#include <device.h>
+#include <flash_map.h>
+#include <flash.h>
+#include <soc.h>
+
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+struct layout_data {
+	u32_t area_idx;
+	u32_t area_off;
+	u32_t area_len;
+	void *ret;        /* struct flash_area* or struct flash_sector* */
+	u32_t ret_idx;
+	u32_t ret_len;
+	int status;
+};
+#endif /* CONFIG_FLASH_PAGE_LAYOUT */
+
+struct driver_map_entry {
+	u8_t id;
+	const char * const name;
+};
+
+static const struct driver_map_entry  flash_drivers_map[] = {
+#ifdef FLASH_DRIVER_NAME /* SoC embedded flash driver */
+	{SOC_FLASH_0_ID, FLASH_DRIVER_NAME},
+#endif
+#ifdef CONFIG_SPI_FLASH_W25QXXDV
+	{SPI_FLASH_0_ID, CONFIG_SPI_FLASH_W25QXXDV_DRV_NAME},
+#endif
+};
+
+const struct flash_area *flash_map;
+extern const int flash_map_entries;
+
+int flash_area_open(u8_t id, const struct flash_area **fap)
+{
+	const struct flash_area *area;
+	int i;
+
+	if (flash_map == NULL) {
+		return -EACCES;
+	}
+
+	for (i = 0; i < flash_map_entries; i++) {
+		area = flash_map + i;
+		if (area->fa_id == id) {
+			*fap = area;
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+void flash_area_close(const struct flash_area *fa)
+{
+	/* nothing to do for now */
+}
+
+static struct device *get_flah_dev_from_id(u8_t id)
+{
+	for (int i = 0; i < ARRAY_SIZE(flash_drivers_map); i++) {
+		if (flash_drivers_map[i].id == id) {
+			return device_get_binding(flash_drivers_map[i].name);
+		}
+	}
+
+	k_panic();
+}
+
+static inline bool is_in_flash_area_bounds(const struct flash_area *fa,
+					   off_t off, size_t len)
+{
+	return (off <= fa->fa_size && off + len <= fa->fa_size);
+}
+
+struct flash_area const *get_flash_area_from_id(int idx)
+{
+	for (int i = 0; i < flash_map_entries; i++) {
+		if (flash_map[i].fa_id == idx) {
+			return &flash_map[i];
+		}
+	}
+
+	return NULL;
+}
+
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+/*
+ * Check if a flash_page_foreach() callback should exit early, due to
+ * one of the following conditions:
+ *
+ * - The flash page described by "info" is before the area of interest
+ *   described in "data"
+ * - The flash page is after the end of the area
+ * - There are too many flash pages on the device to fit in the array
+ *   held in data->ret. In this case, data->status is set to -ENOMEM.
+ *
+ * The value to return to flash_page_foreach() is stored in
+ * "bail_value" if the callback should exit early.
+ */
+static bool should_bail(const struct flash_pages_info *info,
+						struct layout_data *data,
+						bool *bail_value)
+{
+	if (info->start_offset < data->area_off) {
+		*bail_value = true;
+		return true;
+	} else if (info->start_offset >= data->area_off + data->area_len) {
+		*bail_value = false;
+		return true;
+	} else if (data->ret_idx >= data->ret_len) {
+		data->status = -ENOMEM;
+		*bail_value = false;
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Generic page layout discovery routine. This is kept separate to
+ * support both the deprecated flash_area_to_sectors() and the current
+ * flash_area_get_sectors(). A lot of this can be inlined once
+ * flash_area_to_sectors() is removed.
+ */
+static int flash_area_layout(int idx, int *cnt, void *ret,
+flash_page_cb cb, struct layout_data *cb_data)
+{
+	struct device *flash_dev;
+
+	cb_data->area_idx = idx;
+
+	const struct flash_area *fa;
+
+	fa = get_flash_area_from_id(idx);
+	if (fa == NULL) {
+		return -EINVAL;
+	}
+
+	cb_data->area_idx = idx;
+	cb_data->area_off = fa->fa_off;
+	cb_data->area_len = fa->fa_size;
+
+	cb_data->ret = ret;
+	cb_data->ret_idx = 0;
+	cb_data->ret_len = *cnt;
+	cb_data->status = 0;
+
+	flash_dev = get_flah_dev_from_id(fa->fa_device_id);
+
+	flash_page_foreach(flash_dev, cb, cb_data);
+
+	if (cb_data->status == 0) {
+		*cnt = cb_data->ret_idx;
+	}
+
+	return cb_data->status;
+}
+
+static bool get_sectors_cb(const struct flash_pages_info *info, void *datav)
+{
+	struct layout_data *data = datav;
+	struct flash_sector *ret = data->ret;
+	bool bail;
+
+	if (should_bail(info, data, &bail)) {
+		return bail;
+	}
+
+	ret[data->ret_idx].fs_off = info->start_offset - data->area_off;
+	ret[data->ret_idx].fs_size = info->size;
+	data->ret_idx++;
+
+	return true;
+}
+
+int flash_area_get_sectors(int idx, uint32_t *cnt, struct flash_sector *ret)
+{
+	struct layout_data data;
+
+	return flash_area_layout(idx, cnt, ret, get_sectors_cb, &data);
+}
+#endif /* CONFIG_FLASH_PAGE_LAYOUT */
+
+int flash_area_read(const struct flash_area *fa, off_t off, void *dst,
+		    size_t len)
+{
+	struct device *dev;
+
+	if (!is_in_flash_area_bounds(fa, off, len)) {
+		return -1;
+	}
+
+	dev = get_flah_dev_from_id(fa->fa_device_id);
+
+	return flash_read(dev, fa->fa_off + off, dst, len);
+}
+
+int flash_area_write(const struct flash_area *fa, off_t off, const void *src,
+		     size_t len)
+{
+	struct device *flash_dev;
+	int rc;
+
+	if (!is_in_flash_area_bounds(fa, off, len)) {
+		return -1;
+	}
+
+	flash_dev = get_flah_dev_from_id(fa->fa_device_id);
+
+	rc = flash_write_protection_set(flash_dev, false);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_write(flash_dev, fa->fa_off + off, (void *)src, len);
+
+	/* Ignore errors here - this does not affect write operation */
+	(void) flash_write_protection_set(flash_dev, true);
+
+	return rc;
+}
+
+int flash_area_erase(const struct flash_area *fa, off_t off, size_t len)
+{
+	struct device *flash_dev;
+	int rc;
+
+	if (!is_in_flash_area_bounds(fa, off, len)) {
+		return -1;
+	}
+
+	flash_dev = get_flah_dev_from_id(fa->fa_device_id);
+
+	rc = flash_write_protection_set(flash_dev, false);
+	if (rc) {
+		return rc;
+	}
+
+	rc = flash_erase(flash_dev, fa->fa_off + off, len);
+
+	/* Ignore errors here - this does not affect write operation */
+	(void) flash_write_protection_set(flash_dev, true);
+
+	return rc;
+}
+
+u8_t flash_area_align(const struct flash_area *fa)
+{
+	struct device *dev;
+
+	dev = get_flah_dev_from_id(fa->fa_device_id);
+
+	return flash_get_write_block_size(dev);
+}
+
+void flash_map_init(void)
+{
+}

subsys/storage/flash_map/flash_map_default.c

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+/*
+ * Copyright (c) 2017 Nordic Semiconductor ASA
+ * Copyright (c) 2015 Runtime Inc
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr.h>
+#include <flash_map.h>
+
+const struct flash_area default_flash_map[] = {
+	/* FLASH_AREA_BOOTLOADER */
+	{
+		.fa_id = 0,
+		.fa_device_id = SOC_FLASH_0_ID,
+		.fa_off = FLASH_AREA_MCUBOOT_OFFSET,
+		.fa_size = FLASH_AREA_MCUBOOT_SIZE,
+	},
+
+	/* FLASH_AREA_IMAGE_0 */
+	{
+		.fa_id = 1,
+		.fa_device_id = SOC_FLASH_0_ID,
+		.fa_off = FLASH_AREA_IMAGE_0_OFFSET,
+		.fa_size = FLASH_AREA_IMAGE_0_SIZE,
+	},
+
+	/* FLASH_AREA_IMAGE_1 */
+	{
+		.fa_id = 2,
+		.fa_device_id = SOC_FLASH_0_ID,
+		.fa_off = FLASH_AREA_IMAGE_1_OFFSET,
+		.fa_size = FLASH_AREA_IMAGE_1_SIZE,
+	},
+
+	/* FLASH_AREA_IMAGE_SCRATCH */
+	{
+		.fa_id = 3,
+		.fa_device_id = SOC_FLASH_0_ID,
+		.fa_off = FLASH_AREA_IMAGE_SCRATCH_OFFSET,
+		.fa_size = FLASH_AREA_IMAGE_SCRATCH_SIZE,
+	},
+
+#ifdef CONFIG_FILE_SYSTEM_NFFS
+	/* FLASH_AREA_NFFS_ */
+	{
+		.fa_id = 4,
+		.fa_device_id = SOC_FLASH_0_ID,
+		.fa_off = FLASH_AREA_NFFS_OFFSET,
+		.fa_size = FLASH_AREA_NFFS_SIZE,
+	},
+#endif
+};
+
+const int flash_map_entries = ARRAY_SIZE(default_flash_map);
+const struct flash_area *flash_map = default_flash_map;