scsi: ufs: docs: ABI: Add wb_on documentation for new entry wb_on

Adds UFS sysfs documentation for new entry wb_on.

[mkp: fix doc formatting]

Link: https://lore.kernel.org/r/20210119163847.20165-3-huobean@gmail.com
Signed-off-by: Bean Huo <beanhuo@micron.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
fix format

diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index adc0d0e..375a10f 100644 (file)
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1153,3 +1153,14 @@ Description:     This entry shows the configured size of WriteBooster buffer.
                0400h corresponds to 4GB.
 
                The file is read only.
+
+What:          /sys/bus/platform/drivers/ufshcd/*/wb_on
+Date:          January 2021
+Contact:       Bean Huo <beanhuo@micron.com>
+Description:   This node is used to set or display whether UFS WriteBooster is
+               enabled. Echo 0 to this file to disable UFS WriteBooster or 1 to
+               enable it. The WriteBooster is enabled after power-on/reset,
+               however, it will be disabled/enable while CLK scaling down/up
+               (if the platform supports UFSHCD_CAP_CLK_SCALING). For a
+               platform that doesn't support UFSHCD_CAP_CLK_SCALING, we can
+               disable/enable WriteBooster through this sysfs node.