env: mmc: add erase-function

this adds erase environment for mmc storage

squashed fixes:
 - add CONFIG_CMD_ERASEENV
 - env: erase redundant offset if defined
 - changes mentioned by Simon
 - fix whitespaces around errmsg

Suggested-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>

diff --git a/env/mmc.c b/env/mmc.c
index c3cf35d..b7b833f 100644 (file)
--- a/env/mmc.c
+++ b/env/mmc.c
@@ -242,6 +242,54 @@ fini:
        fini_mmc_for_env(mmc);
        return ret;
 }
+
+#if defined(CONFIG_CMD_ERASEENV)
+static inline int erase_env(struct mmc *mmc, unsigned long size,
+                           unsigned long offset)
+{
+       uint blk_start, blk_cnt, n;
+       struct blk_desc *desc = mmc_get_blk_desc(mmc);
+
+       blk_start       = ALIGN(offset, mmc->write_bl_len) / mmc->write_bl_len;
+       blk_cnt         = ALIGN(size, mmc->write_bl_len) / mmc->write_bl_len;
+
+       n = blk_derase(desc, blk_start, blk_cnt);
+       printf("%d blocks erased: %s\n", n, (n == blk_cnt) ? "OK" : "ERROR");
+
+       return (n == blk_cnt) ? 0 : 1;
+}
+
+static int env_mmc_erase(void)
+{
+       int dev = mmc_get_env_dev();
+       struct mmc *mmc = find_mmc_device(dev);
+       int     ret, copy = 0;
+       u32     offset;
+       const char *errmsg;
+
+       errmsg = init_mmc_for_env(mmc);
+       if (errmsg) {
+               printf("%s\n", errmsg);
+               return 1;
+       }
+
+       if (mmc_get_env_addr(mmc, copy, &offset))
+               return CMD_RET_FAILURE;
+
+       ret = erase_env(mmc, CONFIG_ENV_SIZE, offset);
+
+#ifdef CONFIG_ENV_OFFSET_REDUND
+       copy = 1;
+
+       if (mmc_get_env_addr(mmc, copy, &offset))
+               return CMD_RET_FAILURE;
+
+       ret |= erase_env(mmc, CONFIG_ENV_SIZE, offset);
+#endif
+
+       return ret;
+}
+#endif /* CONFIG_CMD_ERASEENV */
 #endif /* CONFIG_CMD_SAVEENV && !CONFIG_SPL_BUILD */
 
 static inline int read_env(struct mmc *mmc, unsigned long size,
@@ -351,5 +399,8 @@ U_BOOT_ENV_LOCATION(mmc) = {
        .load           = env_mmc_load,
 #ifndef CONFIG_SPL_BUILD
        .save           = env_save_ptr(env_mmc_save),
+#if defined(CONFIG_CMD_ERASEENV)
+       .erase          = env_mmc_erase,
+#endif
 #endif
 };