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>

2 files changed, 55 insertions, 30 deletions

diff --git a/Documentation/scsi/index.rst b/Documentation/scsi/index.rst
index df005cb94f6b..27720d145eff 100644
--- a/Documentation/scsi/index.rst
+++ b/Documentation/scsi/index.rst
@@ -44,5 +44,6 @@ Linux SCSI Subsystem
    sym53c500_cs
    sym53c8xx_2
    tcm_qla2xxx
+   ufs
 
    scsi_transport_srp/figures
diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.rst
index 81842ec3e116..a920c0a5a1f6 100644
--- a/Documentation/scsi/ufs.txt
+++ b/Documentation/scsi/ufs.rst
@@ -1,24 +1,26 @@
-                       Universal Flash Storage
-                       =======================
+.. SPDX-License-Identifier: GPL-2.0
 
+=======================
+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
+.. 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
@@ -28,19 +30,25 @@ 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,
+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)
+
+   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)
+
+   - 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.
@@ -48,16 +56,22 @@ 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
+
+  * 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
+  * 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
@@ -65,10 +79,12 @@ UFS communication architecture consists of following layers,
      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.
@@ -76,20 +92,23 @@ UFS communication architecture consists of following layers,
     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
@@ -98,12 +117,14 @@ 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
@@ -112,11 +133,13 @@ The current UFSHCD implementation supports following functionality,
   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
@@ -129,7 +152,7 @@ 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
@@ -138,7 +161,7 @@ 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:
+send SG_IO with the applicable sg_io_v4::
 
 	io_hdr_v4.guard = 'Q';
 	io_hdr_v4.protocol = BSG_PROTOCOL_SCSI;
@@ -166,6 +189,7 @@ upiu-based protocol is available at:
 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
+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