ufs: query descriptor API

Introduces the API for sending queries with descriptors.
A descriptor is a block or page of parameters that describe the device.
The descriptors are classified into types and can range in size
from 2 bytes through 255 bytes.
All descriptors have a length value as their first element, and a type
identification element as their second byte.
All descriptors are readable and some may be write once.
They are accessed using their type, index and selector.

Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: Raviv Shvili <rshvili@codeaurora.org>
Acked-by: Santosh Y <santoshsy@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/ufs/ufs.h

@@ -41,7 +41,8 @@
 
 #define MAX_CDB_SIZE	16
 #define GENERAL_UPIU_REQUEST_SIZE 32
-#define QUERY_DESC_MAX_SIZE       256
+#define QUERY_DESC_MAX_SIZE       255
+#define QUERY_DESC_MIN_SIZE       2
 #define QUERY_OSF_SIZE            (GENERAL_UPIU_REQUEST_SIZE - \
 					(sizeof(struct utp_upiu_header)))
 
@@ -117,6 +118,20 @@ enum attr_idn {
 	QUERY_ATTR_IDN_EE_STATUS	= 0x0E,
 };
 
+/* Descriptor idn for Query requests */
+enum desc_idn {
+	QUERY_DESC_IDN_DEVICE		= 0x0,
+	QUERY_DESC_IDN_CONFIGURAION	= 0x1,
+	QUERY_DESC_IDN_UNIT		= 0x2,
+	QUERY_DESC_IDN_RFU_0		= 0x3,
+	QUERY_DESC_IDN_INTERCONNECT	= 0x4,
+	QUERY_DESC_IDN_STRING		= 0x5,
+	QUERY_DESC_IDN_RFU_1		= 0x6,
+	QUERY_DESC_IDN_GEOMETRY		= 0x7,
+	QUERY_DESC_IDN_POWER		= 0x8,
+	QUERY_DESC_IDN_RFU_2		= 0x9,
+};
+
 /* Exception event mask values */
 enum {
 	MASK_EE_STATUS		= 0xFFFF,