dm: blk: Allow blk_create_device() to allocate the device number

Allow a devnum parameter of -1 to indicate that the device number should be
alocated automatically. The next highest available device number for that
interface type is used.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 3687b9a100081e9c7728c5881b72f7350d2fd300..c947d950232aca460daa5de7ce166bd7a6b172dc 100644 (file)
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -411,6 +411,26 @@ int blk_prepare_device(struct udevice *dev)
        return 0;
 }
 
+int blk_find_max_devnum(enum if_type if_type)
+{
+       struct udevice *dev;
+       int max_devnum = -ENODEV;
+       struct uclass *uc;
+       int ret;
+
+       ret = uclass_get(UCLASS_BLK, &uc);
+       if (ret)
+               return ret;
+       uclass_foreach_dev(dev, uc) {
+               struct blk_desc *desc = dev_get_uclass_platdata(dev);
+
+               if (desc->if_type == if_type && desc->devnum > max_devnum)
+                       max_devnum = desc->devnum;
+       }
+
+       return max_devnum;
+}
+
 int blk_create_device(struct udevice *parent, const char *drv_name,
                      const char *name, int if_type, int devnum, int blksz,
                      lbaint_t size, struct udevice **devp)
@@ -428,6 +448,15 @@ int blk_create_device(struct udevice *parent, const char *drv_name,
        desc->lba = size / blksz;
        desc->part_type = PART_TYPE_UNKNOWN;
        desc->bdev = dev;
+       if (devnum == -1) {
+               ret = blk_find_max_devnum(if_type);
+               if (ret == -ENODEV)
+                       devnum = 0;
+               else if (ret < 0)
+                       return ret;
+               else
+                       devnum = ret + 1;
+       }
        desc->devnum = devnum;
        *devp = dev;
 

diff --git a/include/blk.h b/include/blk.h
index 2caac9c96b68be6f95d1e5d42457afccf9560265..547c3b48dcac41e386492f50f11d0e811ba2d3ba 100644 (file)
--- a/include/blk.h
+++ b/include/blk.h
@@ -270,7 +270,8 @@ int blk_next_device(struct udevice **devp);
  * @drv_name:  Driver name to use for the block device
  * @name:      Name for the device
  * @if_type:   Interface type (enum if_type_t)
- * @devnum:    Device number, specific to the interface type
+ * @devnum:    Device number, specific to the interface type, or -1 to
+ *             allocate the next available number
  * @blksz:     Block size of the device in bytes (typically 512)
  * @size:      Total size of the device in bytes
  * @devp:      the new device (which has not been probed)
@@ -299,6 +300,18 @@ int blk_prepare_device(struct udevice *dev);
  */
 int blk_unbind_all(int if_type);
 
+/**
+ * blk_find_max_devnum() - find the maximum device number for an interface type
+ *
+ * Finds the last allocated device number for an interface type @if_type. The
+ * next number is safe to use for a newly allocated device.
+ *
+ * @if_type:   Interface type to scan
+ * @return maximum device number found, or -ENODEV if none, or other -ve on
+ * error
+ */
+int blk_find_max_devnum(enum if_type if_type);
+
 #else
 #include <errno.h>
 /*