From: Bean Huo <beanhuo@xxxxxxxxxx>
Introduce a sysfs node named 'rtc_update_ms' within the kernel, enabling
user to adjust the RTC periodic update frequency to suit the specific
requirements of the system and UFS. Also, this patch allows the user to
disable/enable periodic update RTC in the UFS idle time.
Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
Acked-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
Documentation/ABI/testing/sysfs-driver-ufs | 7 +++++
drivers/ufs/core/ufs-sysfs.c | 31 ++++++++++++++++++++++
drivers/ufs/core/ufshcd.c | 11 ++++++--
include/ufs/ufs.h | 1 +
4 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-driver-ufs b/Documentation/ABI/testing/sysfs-driver-ufs
index b73067bb5ea2..5bf7073b4f75 100644
--- a/Documentation/ABI/testing/sysfs-driver-ufs
+++ b/Documentation/ABI/testing/sysfs-driver-ufs
@@ -1523,3 +1523,10 @@ Description: Indicates status of Write Booster.
The file is read only.
+What: /sys/bus/platform/drivers/ufshcd/*/rtc_update_ms
+What: /sys/bus/platform/devices/*.ufs/rtc_update_ms
+Date: November 2023
+Contact: Bean Huo <beanhuo@xxxxxxxxxx>
+Description:
+ rtc_update_ms indicates how often the host should synchronize or update the
+ UFS RTC. If set to 0, this will disable UFS RTC periodic update.
diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index 05b10ca90b50..e6d12289e017 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -302,6 +302,35 @@ static ssize_t wb_on_store(struct device *dev, struct device_attribute *attr,
return res < 0 ? res : count;
}
+static ssize_t rtc_update_ms_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%d\n", hba->dev_info.rtc_update_period);
+}
+
+static ssize_t rtc_update_ms_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct ufs_hba *hba = dev_get_drvdata(dev);
+ unsigned int ms;
+ bool resume_period_update = false;
+
+ if (kstrtouint(buf, 0, &ms))
+ return -EINVAL;
+
+ if (!hba->dev_info.rtc_update_period && ms > 0)
+ resume_period_update = true;
+ /* Minimum and maximum update frequency should be synchronized with all UFS vendors */
+ hba->dev_info.rtc_update_period = ms;
+
+ if (resume_period_update)
+ schedule_delayed_work(&hba->ufs_rtc_update_work,
+ msecs_to_jiffies(hba->dev_info.rtc_update_period));
+ return count;
+}
+
static ssize_t enable_wb_buf_flush_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -386,6 +415,7 @@ static DEVICE_ATTR_RW(auto_hibern8);
static DEVICE_ATTR_RW(wb_on);
static DEVICE_ATTR_RW(enable_wb_buf_flush);
static DEVICE_ATTR_RW(wb_flush_threshold);
+static DEVICE_ATTR_RW(rtc_update_ms);
static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
&dev_attr_rpm_lvl.attr,
@@ -398,6 +428,7 @@ static struct attribute *ufs_sysfs_ufshcd_attrs[] = {
&dev_attr_wb_on.attr,
&dev_attr_enable_wb_buf_flush.attr,
&dev_attr_wb_flush_threshold.attr,
+ &dev_attr_rtc_update_ms.attr,
NULL
};
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index cda1e1080446..5ebc9c957236 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -8235,9 +8235,9 @@ static void ufshcd_rtc_work(struct work_struct *work)
if (!ufshcd_is_ufs_dev_busy(hba) && hba->ufshcd_state == UFSHCD_STATE_OPERATIONAL)
ufshcd_update_rtc(hba);
- if (ufshcd_is_ufs_dev_active(hba))
+ if (ufshcd_is_ufs_dev_active(hba) && hba->dev_info.rtc_update_period)
schedule_delayed_work(&hba->ufs_rtc_update_work,
- msecs_to_jiffies(UFS_RTC_UPDATE_INTERVAL_MS));
+ msecs_to_jiffies(hba->dev_info.rtc_update_period));
}
static void ufs_init_rtc(struct ufs_hba *hba, u8 *desc_buf)
@@ -8259,6 +8259,13 @@ static void ufs_init_rtc(struct ufs_hba *hba, u8 *desc_buf)
dev_info->rtc_type = UFS_RTC_RELATIVE;
dev_info->rtc_time_baseline = 0;
}
+
+ /*
+ * We ignore TIME_PERIOD defined in wPeriodicRTCUpdate because Spec does not clearly state
+ * how to calculate the specific update period for each time unit. And we disable periodic
+ * RTC update work, let user configure by sysfs node according to specific circumstance.
+ */
+ dev_info->rtc_update_period = 0;
}
static int ufs_get_device_desc(struct ufs_hba *hba)
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index 7e7169d94596..b6003749bc83 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -591,6 +591,7 @@ struct ufs_dev_info {
/* UFS RTC */
enum ufs_rtc_time rtc_type;
time64_t rtc_time_baseline;
+ u32 rtc_update_period;
};
/*
--
2.34.1
