Allows userspace to check if Clock Scaling and Write Booster are
supported.
Signed-off-by: Daniil Lunev <dlunev@xxxxxxxxxxxx>
---
Changes in v7:
* Move the comment to the documnetation
* Update the month on the documentation
Changes in v6:
* Add comment to clarify meaning of the "capbilities" sysfs group.
Changes in v5:
* Correct wording for clock scaling.
* Correct wording for the commit message.
Changes in v4:
* Dropped crypto node per Eric Biggers mentioning it can be queried from
disk's queue node
Changes in v3:
* Expose each capability individually.
* Update documentation to represent new scheme.
Changes in v2:
* Add documentation entry for the new sysfs node.
Documentation/ABI/testing/sysfs-driver-ufs | 37 ++++++++++++++++++++++
drivers/ufs/core/ufs-sysfs.c | 35 ++++++++++++++++++++
2 files changed, 72 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index 6b248abb1bd71..78f3e393d2498 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1591,6 +1591,43 @@ Description: This entry shows the status of HPB.
The file is read only.
+Contact: Daniil Lunev <dlunev@xxxxxxxxxxxx>
+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@xxxxxxxxxxxx>
+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@xxxxxxxxxxxx>
+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@xxxxxxxxxxxx>
+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@xxxxxxx>
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 0a088b47d5570..75d4287657c80 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -279,6 +279,40 @@ static const struct attribute_group ufs_sysfs_default_group = {
.attrs = ufs_sysfs_ufshcd_attrs,
};
+static ssize_t clock_scaling_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%d\n", ufshcd_is_clkscaling_supported(hba));
+}
+
+static ssize_t write_booster_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%d\n", ufshcd_is_wb_allowed(hba));
+}
+
+static DEVICE_ATTR_RO(clock_scaling);
+static DEVICE_ATTR_RO(write_booster);
+
+/*
+ * See Documentation/ABI/testing/sysfs-driver-ufs for the semantics of this
+ * group.
+ */
+static struct attribute *ufs_sysfs_capabilities_attrs[] = {
+ &dev_attr_clock_scaling.attr,
+ &dev_attr_write_booster.attr,
+ NULL
+};
+
+static const struct attribute_group ufs_sysfs_capabilities_group = {
+ .name = "capabilities",
+ .attrs = ufs_sysfs_capabilities_attrs,
+};
+
static ssize_t monitor_enable_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1134,6 +1168,7 @@ static const struct attribute_group ufs_sysfs_attributes_group = {
static const struct attribute_group *ufs_sysfs_groups[] = {
&ufs_sysfs_default_group,
+ &ufs_sysfs_capabilities_group,
&ufs_sysfs_monitor_group,
&ufs_sysfs_device_descriptor_group,
&ufs_sysfs_interconnect_descriptor_group,
--
2.31.0
