From 91ca757b9ae88d32415429d0903798d9ea0c07af Mon Sep 17 00:00:00 2001
From: Benjamin Valentin <benjamin.valentin@ml-pa.com>
Date: Mon, 7 Feb 2022 11:40:27 +0100
Subject: [PATCH] drivers/mtd_sdcard: implement erase_sector()

---
 drivers/include/mtd_sdcard.h    |  3 ++-
 drivers/mtd_sdcard/mtd_sdcard.c | 43 ++++++++++++++++++++++++---------
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/drivers/include/mtd_sdcard.h b/drivers/include/mtd_sdcard.h
index b4228c30fd..2c7cabf92f 100644
--- a/drivers/include/mtd_sdcard.h
+++ b/drivers/include/mtd_sdcard.h
@@ -55,7 +55,8 @@ typedef struct {
  *          the sector first.
  *          Attention: an erase call will therefore NOT touch the content,
  *          so enable this feature to ensure overriding the data.
- *          This feature is currently not supported.
+ *
+ *          This feature requires the `mtd_write_page` module.
  */
 #ifdef DOXYGEN
 #define CONFIG_MTD_SDCARD_ERASE
diff --git a/drivers/mtd_sdcard/mtd_sdcard.c b/drivers/mtd_sdcard/mtd_sdcard.c
index 765529dc48..788580eae4 100644
--- a/drivers/mtd_sdcard/mtd_sdcard.c
+++ b/drivers/mtd_sdcard/mtd_sdcard.c
@@ -138,21 +138,40 @@ static int mtd_sdcard_write_page(mtd_dev_t *dev, const void *buff, uint32_t page
     return size;
 }
 
-static int mtd_sdcard_erase(mtd_dev_t *dev,
-                            uint32_t addr,
-                            uint32_t size)
+static int mtd_sdcard_erase_sector(mtd_dev_t *dev, uint32_t sector, uint32_t count)
 {
-    DEBUG("mtd_sdcard_erase: addr:%" PRIu32 " size:%" PRIu32 "\n", addr, size);
-    (void)dev;
-    (void)addr;
-    (void)size;
+#if IS_ACTIVE(CONFIG_MTD_SDCARD_ERASE) && IS_USED(MODULE_MTD_WRITE_PAGE)
+    mtd_sdcard_t *mtd_sd = (mtd_sdcard_t*)dev;
 
-    if (!IS_ACTIVE(CONFIG_MTD_SDCARD_ERASE)) {
-        return 0;
+    DEBUG("mtd_sdcard_erase_sector: sector: %" PRIu32 " count: %" PRIu32 "\n",
+          sector, count);
+
+    if (dev->work_area == NULL) {
+        DEBUG("mtd_sdcard_erase_sector: no work area\n");
+        return -ENOTSUP;
     }
-    else {
-        return -ENOTSUP; /* explicit erase currently not supported */
+    memset(dev->work_area, 0, SD_HC_BLOCK_SIZE);
+    while (count) {
+        sd_rw_response_t err;
+        sdcard_spi_write_blocks(mtd_sd->sd_card, sector,
+                                dev->work_area, SD_HC_BLOCK_SIZE,
+                                1, &err);
+        if (err != SD_RW_OK) {
+            printf("err: %d\n", err);
+            return -EIO;
+        }
+        --count;
+        ++sector;
     }
+#else
+    (void)dev;
+    (void)sector;
+    (void)count;
+    if (IS_ACTIVE(CONFIG_MTD_SDCARD_ERASE)) {
+        return -ENOTSUP;
+    }
+#endif
+    return 0;
 }
 
 static int mtd_sdcard_power(mtd_dev_t *dev, enum mtd_power_state power)
@@ -199,6 +218,6 @@ const mtd_desc_t mtd_sdcard_driver = {
     .read_page = mtd_sdcard_read_page,
     .write = mtd_sdcard_write,
     .write_page = mtd_sdcard_write_page,
-    .erase = mtd_sdcard_erase,
+    .erase_sector = mtd_sdcard_erase_sector,
     .power = mtd_sdcard_power,
 };