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Diffstat (limited to 'include/linux/usb/storage.h')
-rw-r--r--include/linux/usb/storage.h25
1 files changed, 16 insertions, 9 deletions
diff --git a/include/linux/usb/storage.h b/include/linux/usb/storage.h
index cb33fff2ba0b..51be3bb8fccb 100644
--- a/include/linux/usb/storage.h
+++ b/include/linux/usb/storage.h
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
#ifndef __LINUX_USB_STORAGE_H
#define __LINUX_USB_STORAGE_H
@@ -8,8 +9,6 @@
*
* This file contains definitions taken from the
* USB Mass Storage Class Specification Overview
- *
- * Distributed under the terms of the GNU GPL, version two.
*/
/* Storage subclass codes */
@@ -45,29 +44,29 @@
#define USB_PR_DEVICE 0xff /* Use device's value */
- /*
- * Bulk only data structures
- */
+/*
+ * Bulk only data structures
+ */
/* command block wrapper */
struct bulk_cb_wrap {
__le32 Signature; /* contains 'USBC' */
__u32 Tag; /* unique per command id */
__le32 DataTransferLength; /* size of data */
- __u8 Flags; /* direction in bit 0 */
+ __u8 Flags; /* direction in bit 7 */
__u8 Lun; /* LUN normally 0 */
- __u8 Length; /* of of the CDB */
+ __u8 Length; /* length of the CDB */
__u8 CDB[16]; /* max command */
};
#define US_BULK_CB_WRAP_LEN 31
-#define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
+#define US_BULK_CB_SIGN 0x43425355 /* spells out 'USBC' */
#define US_BULK_FLAG_IN (1 << 7)
#define US_BULK_FLAG_OUT 0
/* command status wrapper */
struct bulk_cs_wrap {
- __le32 Signature; /* should = 'USBS' */
+ __le32 Signature; /* contains 'USBS' */
__u32 Tag; /* same as original command */
__le32 Residue; /* amount not transferred */
__u8 Status; /* see below */
@@ -83,4 +82,12 @@ struct bulk_cs_wrap {
#define US_BULK_RESET_REQUEST 0xff
#define US_BULK_GET_MAX_LUN 0xfe
+/*
+ * If 4 LUNs are supported then the LUNs would be
+ * numbered from 0 to 3, and the return value for
+ * US_BULK_GET_MAX_LUN request would be 3. The valid
+ * LUN field is 4 bits wide, the upper limit is 0x0f.
+ */
+#define US_BULK_MAX_LUN_LIMIT 0x0f
+
#endif