[PATCH v1 2/2] scsi: ufs: core: Add sysfs node for UFS RTC update

[Bean Huo <beanhuo@iokpp.de>]

From: Bean Huo <beanhuo@micron.com>

This patch introduces a sysfs node named 'rtc_update_ms' within the kernel, enabling users 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 periodic update RTC  in the UFS idle time.

Signed-off-by: Bean Huo <beanhuo@micron.com>
---
 drivers/ufs/core/ufs-sysfs.c | 31 +++++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd.c    |  4 ++--
 2 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
index c95906443d5f..d42846316a86 100644
--- a/drivers/ufs/core/ufs-sysfs.c
+++ b/drivers/ufs/core/ufs-sysfs.c
@@ -255,6 +255,35 @@ 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;
+
+	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_delayed_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)
@@ -339,6 +368,7 @@ 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,
@@ -351,6 +381,7 @@ 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 f0e3dd3dd280..ae9b60619fd3 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -8234,9 +8234,9 @@ static void ufshcd_rtc_work(struct work_struct *work)
 
 	ufshcd_update_rtc(hba);
 out:
-	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_delayed_work,
-							msecs_to_jiffies(UFS_RTC_UPDATE_EVERY_MS));
+						msecs_to_jiffies(hba->dev_info.rtc_update_period));
 	return;
 }
 
-- 
2.34.1