drivers: disk_flash: Create disk_flash driver

Create a driver that emulates a flash storage on the disk api. This enables e.g. using an spi SD-Card as secondary partition for mcuboot. Signed-off-by: Carlo Kirchmeier <[email protected]>
zephyrproject-rtos · Nov 21, 2023 · 3f0c0ed · 3f0c0ed
1 parent 26fd55e
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diff --git a/drivers/flash/CMakeLists.txt b/drivers/flash/CMakeLists.txt
@@ -26,6 +26,7 @@ if(CONFIG_FLASH_SIMULATOR)
     zephyr_library_sources(flash_simulator_native.c)
   endif()
 endif()
+zephyr_library_sources_ifdef(CONFIG_DISK_FLASH_DRIVER disk_flash.c)
 zephyr_library_sources_ifdef(CONFIG_SPI_FLASH_AT45 spi_flash_at45.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_ITE_IT8XXX2 flash_ite_it8xxx2.c)
 zephyr_library_sources_ifdef(CONFIG_SOC_FLASH_NRF soc_flash_nrf.c)

diff --git a/drivers/flash/Kconfig b/drivers/flash/Kconfig
@@ -138,6 +138,8 @@ source "drivers/flash/Kconfig.sam"
 
 source "drivers/flash/Kconfig.simulator"
 
+source "drivers/flash/Kconfig.disk_flash"
+
 source "drivers/flash/Kconfig.rv32m1"
 
 source "drivers/flash/Kconfig.nordic_qspi_nor"

diff --git a/drivers/flash/Kconfig.disk_flash b/drivers/flash/Kconfig.disk_flash
@@ -0,0 +1,14 @@
+# Disk flash emulator config
+
+# Copyright (c) 2023 Endress+Hauser AG
+# SPDX-License-Identifier: Apache-2.0
+
+config DISK_FLASH_DRIVER
+	bool "Use the flash on disk emulator"
+	default y
+	depends on DT_HAS_ZEPHYR_DISK_FLASH_ENABLED
+	select FLASH_HAS_DRIVER_ENABLED
+	help
+	  This option enables the flash on disk emulator
+	  which can be used to emulate a flash on a disk
+	  device like sd-card or ramdisk.
diff --git a/drivers/flash/disk_flash.c b/drivers/flash/disk_flash.c
@@ -0,0 +1,344 @@
+/*
+ * Copyright (c) 2023 Endress+Hauser AG
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT zephyr_disk_flash
+
+#include <string.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/device.h>
+#include <zephyr/storage/disk_access.h>
+#include <zephyr/drivers/flash.h>
+#include <zephyr/drivers/disk.h>
+
+LOG_MODULE_REGISTER(disk_flash, CONFIG_FLASH_LOG_LEVEL);
+
+struct disk_flash_data {
+	struct k_sem sem;
+	uint8_t *const sector_buf;
+	uint16_t const sector_buf_size;
+	uint32_t disk_total_sector_cnt;
+	uint32_t disk_sector_size;
+};
+
+struct disk_flash_config {
+	uint32_t flash_size;
+	struct flash_parameters flash_parameters;
+	char *disk_name;
+	uint32_t disk_offset;
+
+	IF_ENABLED(CONFIG_FLASH_PAGE_LAYOUT, (struct flash_pages_layout fpl;))
+};
+
+static void acquire_device(const struct device *dev)
+{
+	struct disk_flash_data *const data = dev->data;
+
+	k_sem_take(&data->sem, K_FOREVER);
+}
+
+static void release_device(const struct device *dev)
+{
+	struct disk_flash_data *const data = dev->data;
+
+	k_sem_give(&data->sem);
+}
+
+static int check_boundary(const struct device *dev, off_t offset, size_t len)
+{
+	int ret = 0;
+	const struct disk_flash_config *cfg = dev->config;
+	size_t operation_end = offset + len;
+
+	if (cfg->flash_size < operation_end || offset < 0) {
+		LOG_ERR("Operation out of bounds");
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int disk_flash_read(const struct device *dev, off_t offset, void *dst, size_t len)
+{
+	int ret = 0;
+	uint8_t *dst_buf = dst;
+	const struct disk_flash_config *cfg = dev->config;
+	struct disk_flash_data *data = dev->data;
+	uint32_t write_cursor = 0;
+
+	acquire_device(dev);
+
+	ret = check_boundary(dev, offset, len);
+	if (ret != 0) {
+		goto release_device;
+	}
+
+	if (data->disk_sector_size == 0) {
+		ret = -EINVAL;
+		goto release_device;
+	}
+
+	while (write_cursor < len) {
+		uint32_t read_cursor = cfg->disk_offset + offset + write_cursor;
+		uint32_t read_sector = read_cursor / data->disk_sector_size;
+		uint32_t read_padding = read_cursor % data->disk_sector_size;
+		uint32_t len_write = (len - write_cursor);
+
+		if (read_sector < 0 || read_sector >= data->disk_total_sector_cnt) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (disk_access_read(cfg->disk_name, data->sector_buf, read_sector, 1)) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (len_write > data->sector_buf_size - read_padding) {
+			len_write = data->sector_buf_size - read_padding;
+		}
+
+		memcpy(&dst_buf[write_cursor], &data->sector_buf[read_padding], len_write);
+		write_cursor += len_write;
+	}
+
+release_device:
+	release_device(dev);
+	return ret;
+}
+
+static int disk_flash_write(const struct device *dev, off_t offset, const void *src, size_t len)
+{
+	int ret = 0;
+	const uint8_t *src_buf = src;
+	const struct disk_flash_config *cfg = dev->config;
+	struct disk_flash_data *data = dev->data;
+	uint32_t read_cursor = 0;
+
+	acquire_device(dev);
+
+	ret = check_boundary(dev, offset, len);
+	if (ret != 0) {
+		goto release_device;
+	}
+
+	if (data->disk_sector_size == 0) {
+		ret = -EINVAL;
+		goto release_device;
+	}
+
+	while (read_cursor < len) {
+		uint32_t write_cursor = cfg->disk_offset + offset + read_cursor;
+		uint32_t write_sector = write_cursor / data->disk_sector_size;
+		uint32_t write_padding = write_cursor % data->disk_sector_size;
+		uint32_t len_write = (len - read_cursor);
+
+		if (write_sector < 0 || write_sector >= data->disk_total_sector_cnt) {
+			LOG_ERR("Sector out of bounds");
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (disk_access_read(cfg->disk_name, data->sector_buf, write_sector, 1)) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (len_write > data->sector_buf_size - write_padding) {
+			len_write = data->sector_buf_size - write_padding;
+		}
+
+		memcpy(&data->sector_buf[write_padding], &src_buf[read_cursor], len_write);
+
+		if (disk_access_write(cfg->disk_name, data->sector_buf, write_sector, 1)) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+		read_cursor += len_write;
+	}
+
+release_device:
+	release_device(dev);
+	return ret;
+}
+
+static int disk_flash_erase(const struct device *dev, off_t offset, size_t size)
+{
+	int ret = 0;
+	const struct disk_flash_config *cfg = dev->config;
+	struct disk_flash_data *data = dev->data;
+	uint32_t read_cursor = 0;
+
+	acquire_device(dev);
+
+	ret = check_boundary(dev, offset, size);
+	if (ret != 0) {
+		goto release_device;
+	}
+
+	if (data->disk_sector_size == 0) {
+		ret = -EINVAL;
+		goto release_device;
+	}
+
+	while (read_cursor < size) {
+		uint32_t write_cursor = cfg->disk_offset + offset + read_cursor;
+		uint32_t write_sector = write_cursor / data->disk_sector_size;
+		uint32_t write_padding = write_cursor % data->disk_sector_size;
+		uint32_t len_write = (size - read_cursor);
+
+		if (write_sector < 0 || write_sector >= data->disk_total_sector_cnt) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (disk_access_read(cfg->disk_name, data->sector_buf, write_sector, 1)) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+
+		if (len_write > data->sector_buf_size - write_padding) {
+			len_write = data->sector_buf_size - write_padding;
+		}
+
+		memset(&data->sector_buf[write_padding],
+			cfg->flash_parameters.erase_value,
+			len_write);
+
+		if (disk_access_write(cfg->disk_name, data->sector_buf, write_sector, 1)) {
+			ret = -EINVAL;
+			goto release_device;
+		}
+		read_cursor += len_write;
+	}
+
+release_device:
+	release_device(dev);
+	return ret;
+}
+
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+static void disk_flash_pages_layout(const struct device *dev,
+				    const struct flash_pages_layout **layout, size_t *layout_size)
+{
+	const struct disk_flash_config *cfg = dev->config;
+
+	*layout = &cfg->fpl;
+	*layout_size = 1;
+}
+#endif
+
+static const struct flash_parameters *disk_flash_get_parameters(const struct device *dev)
+{
+	const struct disk_flash_config *cfg = dev->config;
+
+	return &cfg->flash_parameters;
+}
+
+static const struct flash_driver_api disk_flash_api = {
+	.read = disk_flash_read,
+	.write = disk_flash_write,
+	.erase = disk_flash_erase,
+	.get_parameters = disk_flash_get_parameters,
+#if defined(CONFIG_FLASH_PAGE_LAYOUT)
+	.page_layout = disk_flash_pages_layout,
+#endif
+#if defined(CONFIG_FLASH_JESD216_API)
+	.sfdp_read = NULL,
+	.read_jedec_id = NULL,
+#endif
+#if defined(CONFIG_FLASH_EX_OP_ENABLED)
+	.ex_op = NULL,
+#endif
+};
+
+static int disk_flash_init(const struct device *dev)
+{
+	int res = 0;
+	struct disk_flash_data *data = dev->data;
+	const struct disk_flash_config *cfg = dev->config;
+	size_t disk_size = 0;
+
+	k_sem_init(&data->sem, 1, 1);
+
+	res = disk_access_init(cfg->disk_name);
+	if (res != 0) {
+		LOG_ERR("init disk failed: %d", res);
+		goto init_done;
+	}
+
+	res = disk_access_ioctl(cfg->disk_name, DISK_IOCTL_GET_SECTOR_COUNT,
+				&data->disk_total_sector_cnt);
+	if (res != 0) {
+		LOG_ERR("read total sector cnt failed: %d", res);
+		goto init_done;
+	}
+
+
+	res = disk_access_ioctl(cfg->disk_name, DISK_IOCTL_GET_SECTOR_SIZE,
+				&data->disk_sector_size);
+	if (res != 0) {
+		LOG_ERR("read sector size failed: %d", res);
+		goto init_done;
+	}
+
+	if (data->disk_sector_size > data->sector_buf_size) {
+		LOG_ERR("sector size %u of disk to big for buffer %u", data->disk_sector_size,
+			(uint32_t)data->sector_buf_size);
+		res = -EINVAL;
+		goto init_done;
+	}
+
+	if (cfg->disk_offset % data->disk_sector_size != 0) {
+		LOG_WRN("offset is not aligned with disk sectors (disk sector size: %u)",
+			data->disk_sector_size);
+	}
+
+	disk_size = data->disk_sector_size * data->disk_total_sector_cnt;
+	if ((disk_size - cfg->disk_offset) < cfg->flash_size) {
+		LOG_ERR("Underlying disk to small to support flash: %lu < %d",
+			(unsigned long)(disk_size - cfg->disk_offset),
+			cfg->flash_size);
+		res = -EINVAL;
+		goto init_done;
+	}
+
+init_done:
+	return res;
+}
+
+#define DISK_FLASH_DEFINE(index)								\
+	BUILD_ASSERT(DT_INST_PROP(index, size) > 0, "flash_size needs to be > 0");		\
+	BUILD_ASSERT(DT_INST_PROP(index, disk_offset) >= 0, "disk_offset needs to be >= 0");	\
+	uint8_t sector_buf_##index[DT_INST_PROP(index, disk_sector_size)];			\
+	static struct disk_flash_data disk_flash_data_##index = {				\
+		.sector_buf = sector_buf_##index,						\
+		.sector_buf_size = sizeof(sector_buf_##index),					\
+	};											\
+	static const struct disk_flash_config disk_flash_config_##index = {			\
+		.flash_size = DT_INST_PROP(index, size),					\
+		.flash_parameters =								\
+		{										\
+			.write_block_size = 1,							\
+			.erase_value = 0xFF							\
+		},										\
+		IF_ENABLED(									\
+			CONFIG_FLASH_PAGE_LAYOUT,						\
+			(.fpl =									\
+				{								\
+					.pages_count = DT_INST_PROP(index, size),		\
+					.pages_size = 1						\
+				},								\
+			)									\
+		)										\
+		.disk_name = DT_INST_PROP(index, disk_name),					\
+		.disk_offset = DT_INST_PROP(index, disk_offset),				\
+	};											\
+	DEVICE_DT_INST_DEFINE(index, &disk_flash_init, NULL, &disk_flash_data_##index,		\
+			&disk_flash_config_##index,						\
+			DT_STRING_TOKEN(DT_DRV_INST(index), init_level),			\
+			CONFIG_FLASH_INIT_PRIORITY, &disk_flash_api);
+
+DT_INST_FOREACH_STATUS_OKAY(DISK_FLASH_DEFINE)