From 3050daaecc1fff63d1095230e0e212e2ba459856 Mon Sep 17 00:00:00 2001
From: Jordan Yates <jordan@embeint.com>
Date: Fri, 12 Jul 2024 15:05:24 +1000
Subject: [PATCH] storage: disk_access: add `disk_access_erase`

Add the `disk_access_erase` command to complement the read and write
commands.

As a backwards compatible new feature, this increments the API version
from `1.0.0` to `1.1.0`.

Signed-off-by: Jordan Yates <jordan@embeint.com>
---
 include/zephyr/drivers/disk.h        |  3 ++-
 include/zephyr/storage/disk_access.h | 20 +++++++++++++++++++
 subsys/disk/disk_access.c            | 30 ++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/include/zephyr/drivers/disk.h b/include/zephyr/drivers/disk.h
index 18b1c0f3ede..899a3e25be5 100644
--- a/include/zephyr/drivers/disk.h
+++ b/include/zephyr/drivers/disk.h
@@ -23,7 +23,7 @@
  * @brief Interfaces for disks.
  * @defgroup disk_driver_interface Disk Access
  * @since 1.6
- * @version 1.0.0
+ * @version 1.1.0
  * @ingroup io_interfaces
  * @{
  */
@@ -110,6 +110,7 @@ struct disk_operations {
 		    uint32_t start_sector, uint32_t num_sector);
 	int (*write)(struct disk_info *disk, const uint8_t *data_buf,
 		     uint32_t start_sector, uint32_t num_sector);
+	int (*erase)(struct disk_info *disk, uint32_t start_sector, uint32_t num_sector);
 	int (*ioctl)(struct disk_info *disk, uint8_t cmd, void *buff);
 };
 
diff --git a/include/zephyr/storage/disk_access.h b/include/zephyr/storage/disk_access.h
index c06d7d1baf2..4608cb7bb67 100644
--- a/include/zephyr/storage/disk_access.h
+++ b/include/zephyr/storage/disk_access.h
@@ -100,6 +100,26 @@ int disk_access_read(const char *pdrv, uint8_t *data_buf,
 int disk_access_write(const char *pdrv, const uint8_t *data_buf,
 		      uint32_t start_sector, uint32_t num_sector);
 
+enum disk_access_erase_type {
+	/** Erase the physical bytes on the disk to their natural erase value (0x00 or 0xFF) */
+	DISK_ACCESS_ERASE_PHYSICAL = 0,
+};
+
+/**
+ * @brief erase data from disk
+ *
+ * The result of this operation depends on the type of erase, as specified by @a erase_type.
+ *
+ * @param[in] pdrv          Disk name
+ * @param[in] start_sector  Start disk sector to erase
+ * @param[in] num_sector    Number of disk sectors to erase
+ * @param[in] erase_type    Type of erase to perform
+ *
+ * @return 0 on success, negative errno code on fail
+ */
+int disk_access_erase(const char *pdrv, uint32_t start_sector, uint32_t num_sector,
+		      enum disk_access_erase_type erase_type);
+
 /**
  * @brief Get/Configure disk parameters
  *
diff --git a/subsys/disk/disk_access.c b/subsys/disk/disk_access.c
index 313c937c15d..b9512a788ab 100644
--- a/subsys/disk/disk_access.c
+++ b/subsys/disk/disk_access.c
@@ -118,6 +118,36 @@ int disk_access_write(const char *pdrv, const uint8_t *data_buf,
 	return rc;
 }
 
+int disk_access_erase(const char *pdrv, uint32_t start_sector, uint32_t num_sector,
+		      enum disk_access_erase_type erase_type)
+{
+	struct disk_info *disk = disk_access_get_di(pdrv);
+	uint32_t erase_sector_size;
+	int rc = -EINVAL;
+
+	/* Only support physical erase for now.
+	 * This parameter is not passed through to the underlying disk to leave the design
+	 * space open for future erase types (Other erase types may be dedicated functions).
+	 */
+	if (erase_type != DISK_ACCESS_ERASE_PHYSICAL) {
+		return -EINVAL;
+	}
+
+	/* Validate sector sizes, if underlying driver exposes a way to query it */
+	if (disk_access_ioctl(pdrv, DISK_IOCTL_GET_ERASE_BLOCK_SZ, &erase_sector_size) == 0) {
+		/* Alignment check on both start and range of erase request */
+		if ((start_sector % erase_sector_size) || (num_sector % erase_sector_size)) {
+			return -EINVAL;
+		}
+	}
+
+	if ((disk != NULL) && (disk->ops != NULL) && (disk->ops->erase != NULL)) {
+		rc = disk->ops->erase(disk, start_sector, num_sector);
+	}
+
+	return rc;
+}
+
 int disk_access_ioctl(const char *pdrv, uint8_t cmd, void *buf)
 {
 	struct disk_info *disk = disk_access_get_di(pdrv);