drivers/mtd: add MTDIOC_ISBAD ioctl

add an ioctl item MTDIOC_ISBAD
used for flashtool command to check bad blocks

Signed-off-by: zhengyu9 <zhengyu9@xiaomi.com>

Documentation/components/drivers/special/mtd.rst

@@ -36,6 +36,7 @@ See include/nuttx/mtd/mtd.h for additional information.
 
    -  ``MTDIOC_GEOMETRY``: Get MTD geometry
    -  ``MTDIOC_BULKERASE``: Erase the entire device
+   -  ``MTDIOC_ISBAD``: Check if a block is bad
 
    is provided via a single ``ioctl`` method (see
    ``include/nuttx/fs/ioctl.h``):

drivers/mtd/mtd_nand.c

@@ -837,6 +837,15 @@ static int nand_ioctl(FAR struct mtd_dev_s *dev, int cmd, unsigned long arg)
         }
         break;
 
+      case MTDIOC_ISBAD:
+        {
+          FAR struct mtd_bad_block_s *bad_block =
+                                     (FAR struct mtd_bad_block_s *)arg;
+          bad_block->bad_flag = nand_isbad(dev, bad_block->block_num);
+          ret = OK;
+        }
+        break;
+
       default:
         ret = -ENOTTY; /* Bad command */
         break;

include/nuttx/mtd/mtd.h

@@ -85,6 +85,9 @@
                                              * OUT: None
                                              *      Resets the device to the power-on
                                              *      default condition */
+#define MTDIOC_ISBAD        _MTDIOC(0x000e) /* IN: Erase block number
+                                             * OUT: 0=A good block
+                                             *      1=A bad block */
 
 /* Macros to hide implementation */
 
@@ -158,6 +161,14 @@ struct mtd_erase_s
   uint32_t nblocks;     /* Number of blocks to be erased */
 };
 
+/* This structure store the bad block information of a block */
+
+struct mtd_bad_block_s
+{
+  off_t block_num;
+  int bad_flag;
+};
+
 /* This structure defines the interface to a simple memory technology device.
  * It will likely need to be extended in the future to support more complex
  * devices.