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authorDaniil Lunev <dlunev@chromium.org>2022-08-29 08:18:58 +1000
committerMartin K. Petersen <martin.petersen@oracle.com>2022-09-06 22:18:06 -0400
commit2286ade07d74498a62c0ad067a79ca8dcc04016f (patch)
treec73bf76b57dfab8e4dd46b7e1f02733e7743ac20 /Documentation/ABI
parent9806d1b895f42c919620539b8e7621d73ea6d60d (diff)
downloadlinux-2286ade07d74498a62c0ad067a79ca8dcc04016f.tar.gz
scsi: ufs: core: Print UFSHCD capabilities in controller's sysfs node
Userspace may want to manually control when the data should go into
WriteBooster buffer. The control happens via "wb_on" node, but presently,
there is no simple way to check if WriteBooster is supported and
enabled.

Expose the Write Booster and Clock Scaling capabilities to be able to
determine if the Write Booster is available and if its manual control is
blocked by Clock Scaling mechanism.

Link: https://lore.kernel.org/r/20220829081845.v8.1.Ibf9efc9be50783eeee55befa2270b7d38552354c@changeid
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Daniil Lunev <dlunev@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'Documentation/ABI')
-rw-r--r--Documentation/ABI/testing/sysfs-driver-ufs37
1 files changed, 37 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index 91de786f9a71..228aa43e14ed 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1600,6 +1600,43 @@ Description:	This entry shows the status of HPB.
 
 		The file is read only.
 
+Contact:	Daniil Lunev <dlunev@chromium.org>
+What:		/sys/bus/platform/drivers/ufshcd/*/capabilities/
+What:		/sys/bus/platform/devices/*.ufs/capabilities/
+Date:		August 2022
+Description:	The group represents the effective capabilities of the
+		host-device pair. i.e. the capabilities which are enabled in the
+		driver for the specific host controller, supported by the host
+		controller and are supported and/or have compatible
+		configuration on the device side.
+
+Contact:	Daniil Lunev <dlunev@chromium.org>
+What:		/sys/bus/platform/drivers/ufshcd/*/capabilities/clock_scaling
+What:		/sys/bus/platform/devices/*.ufs/capabilities/clock_scaling
+Date:		August 2022
+Contact:	Daniil Lunev <dlunev@chromium.org>
+Description:	Indicates status of clock scaling.
+
+		== ============================
+		0  Clock scaling is not supported.
+		1  Clock scaling is supported.
+		== ============================
+
+		The file is read only.
+
+What:		/sys/bus/platform/drivers/ufshcd/*/capabilities/write_booster
+What:		/sys/bus/platform/devices/*.ufs/capabilities/write_booster
+Date:		August 2022
+Contact:	Daniil Lunev <dlunev@chromium.org>
+Description:	Indicates status of Write Booster.
+
+		== ============================
+		0  Write Booster can not be enabled.
+		1  Write Booster can be enabled.
+		== ============================
+
+		The file is read only.
+
 What:		/sys/class/scsi_device/*/device/hpb_param_sysfs/activation_thld
 Date:		February 2021
 Contact:	Avri Altman <avri.altman@wdc.com>