scsi: docs: convert ufs.txt to ReST

Link: https://lore.kernel.org/r/052d45576e342a217185e91a83793b384b1592a4.1583136624.git.mchehab+huawei@kernel.org
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 0 insertions, 171 deletions

diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.txt
deleted file mode 100644
index 81842ec3e116..000000000000
--- a/Documentation/scsi/ufs.txt
+++ /dev/null
@@ -1,171 +0,0 @@
-                       Universal Flash Storage
-                       =======================
-
-
-Contents
---------
-
-1. Overview
-2. UFS Architecture Overview
-  2.1 Application Layer
-  2.2 UFS Transport Protocol(UTP) layer
-  2.3 UFS Interconnect(UIC) Layer
-3. UFSHCD Overview
-  3.1 UFS controller initialization
-  3.2 UTP Transfer requests
-  3.3 UFS error handling
-  3.4 SCSI Error handling
-
-
-1. Overview
------------
-
-Universal Flash Storage(UFS) is a storage specification for flash devices.
-It is aimed to provide a universal storage interface for both
-embedded and removable flash memory based storage in mobile
-devices such as smart phones and tablet computers. The specification
-is defined by JEDEC Solid State Technology Association. UFS is based
-on MIPI M-PHY physical layer standard. UFS uses MIPI M-PHY as the
-physical layer and MIPI Unipro as the link layer.
-
-The main goals of UFS is to provide,
- * Optimized performance:
-   For UFS version 1.0 and 1.1 the target performance is as follows,
-   Support for Gear1 is mandatory (rate A: 1248Mbps, rate B: 1457.6Mbps)
-   Support for Gear2 is optional (rate A: 2496Mbps, rate B: 2915.2Mbps)
-   Future version of the standard,
-   Gear3 (rate A: 4992Mbps, rate B: 5830.4Mbps)
- * Low power consumption
- * High random IOPs and low latency
-
-
-2. UFS Architecture Overview
-----------------------------
-
-UFS has a layered communication architecture which is based on SCSI
-SAM-5 architectural model.
-
-UFS communication architecture consists of following layers,
-
-2.1 Application Layer
-
-  The Application layer is composed of UFS command set layer(UCS),
-  Task Manager and Device manager. The UFS interface is designed to be
-  protocol agnostic, however SCSI has been selected as a baseline
-  protocol for versions 1.0 and 1.1 of UFS protocol  layer.
-  UFS supports subset of SCSI commands defined by SPC-4 and SBC-3.
-  * UCS: It handles SCSI commands supported by UFS specification.
-  * Task manager: It handles task management functions defined by the
-     UFS which are meant for command queue control.
-  * Device manager: It handles device level operations and device
-     configuration operations. Device level operations mainly involve
-     device power management operations and commands to Interconnect
-     layers. Device level configurations involve handling of query
-     requests which are used to modify and retrieve configuration
-     information of the device.
-
-2.2 UFS Transport Protocol(UTP) layer
-
-  UTP layer provides services for
-  the higher layers through Service Access Points. UTP defines 3
-  service access points for higher layers.
-  * UDM_SAP: Device manager service access point is exposed to device
-    manager for device level operations. These device level operations
-    are done through query requests.
-  * UTP_CMD_SAP: Command service access point is exposed to UFS command
-    set layer(UCS) to transport commands.
-  * UTP_TM_SAP: Task management service access point is exposed to task
-    manager to transport task management functions.
-  UTP transports messages through UFS protocol information unit(UPIU).
-
-2.3 UFS Interconnect(UIC) Layer
-
-  UIC is the lowest layer of UFS layered architecture. It handles
-  connection between UFS host and UFS device. UIC consists of
-  MIPI UniPro and MIPI M-PHY. UIC provides 2 service access points
-  to upper layer,
-  * UIC_SAP: To transport UPIU between UFS host and UFS device.
-  * UIO_SAP: To issue commands to Unipro layers.
-
-
-3. UFSHCD Overview
-------------------
-
-The UFS host controller driver is based on Linux SCSI Framework.
-UFSHCD is a low level device driver which acts as an interface between
-SCSI Midlayer and PCIe based UFS host controllers.
-
-The current UFSHCD implementation supports following functionality,
-
-3.1 UFS controller initialization
-
-  The initialization module brings UFS host controller to active state
-  and prepares the controller to transfer commands/response between
-  UFSHCD and UFS device.
-
-3.2 UTP Transfer requests
-
-  Transfer request handling module of UFSHCD receives SCSI commands
-  from SCSI Midlayer, forms UPIUs and issues the UPIUs to UFS Host
-  controller. Also, the module decodes, responses received from UFS
-  host controller in the form of UPIUs and intimates the SCSI Midlayer
-  of the status of the command.
-
-3.3 UFS error handling
-
-  Error handling module handles Host controller fatal errors,
-  Device fatal errors and UIC interconnect layer related errors.
-
-3.4 SCSI Error handling
-
-  This is done through UFSHCD SCSI error handling routines registered
-  with SCSI Midlayer. Examples of some of the error handling commands
-  issues by SCSI Midlayer are Abort task, Lun reset and host reset.
-  UFSHCD Routines to perform these tasks are registered with
-  SCSI Midlayer through .eh_abort_handler, .eh_device_reset_handler and
-  .eh_host_reset_handler.
-
-In this version of UFSHCD Query requests and power management
-functionality are not implemented.
-
-4. BSG Support
-------------------
-
-This transport driver supports exchanging UFS protocol information units
-(UPIUs) with a UFS device. Typically, user space will allocate
-struct ufs_bsg_request and struct ufs_bsg_reply (see ufs_bsg.h) as
-request_upiu and reply_upiu respectively.  Filling those UPIUs should
-be done in accordance with JEDEC spec UFS2.1 paragraph 10.7.
-*Caveat emptor*: The driver makes no further input validations and sends the
-UPIU to the device as it is.  Open the bsg device in /dev/ufs-bsg and
-send SG_IO with the applicable sg_io_v4:
-
-	io_hdr_v4.guard = 'Q';
-	io_hdr_v4.protocol = BSG_PROTOCOL_SCSI;
-	io_hdr_v4.subprotocol = BSG_SUB_PROTOCOL_SCSI_TRANSPORT;
-	io_hdr_v4.response = (__u64)reply_upiu;
-	io_hdr_v4.max_response_len = reply_len;
-	io_hdr_v4.request_len = request_len;
-	io_hdr_v4.request = (__u64)request_upiu;
-	if (dir == SG_DXFER_TO_DEV) {
-		io_hdr_v4.dout_xfer_len = (uint32_t)byte_cnt;
-		io_hdr_v4.dout_xferp = (uintptr_t)(__u64)buff;
-	} else {
-		io_hdr_v4.din_xfer_len = (uint32_t)byte_cnt;
-		io_hdr_v4.din_xferp = (uintptr_t)(__u64)buff;
-	}
-
-If you wish to read or write a descriptor, use the appropriate xferp of
-sg_io_v4.
-
-The userspace tool that interacts with the ufs-bsg endpoint and uses its
-upiu-based protocol is available at:
-
-	https://github.com/westerndigitalcorporation/ufs-tool
-
-For more detailed information about the tool and its supported
-features, please see the tool's README.
-
-UFS Specifications can be found at,
-UFS - http://www.jedec.org/sites/default/files/docs/JESD220.pdf
-UFSHCI - http://www.jedec.org/sites/default/files/docs/JESD223.pdf