Commit 838f595a authored by Bean Huo's avatar Bean Huo Committed by Martin K. Petersen
Browse files

scsi: ufs: core: Add sysfs node for UFS RTC update 



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: default avatarBean Huo <beanhuo@micron.com>
Link: https://lore.kernel.org/r/20231212220825.85255-4-beanhuo@iokpp.de


Acked-by: default avatarAvri Altman <avri.altman@wdc.com>
Reviewed-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 6bf999e0

Documentation/ABI/testing/sysfs-driver-ufs

+7 −0
Original line number Diff line number Diff line
@@ -1474,3 +1474,10 @@ 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@micron.com>

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.

drivers/ufs/core/ufs-sysfs.c

+31 −0
Original line number Diff line number Diff line
@@ -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 = 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)
@@ -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

};

drivers/ufs/core/ufshcd.c

+9 −2
Original line number Diff line number Diff line
@@ -8233,9 +8233,9 @@ 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)
@@ -8257,6 +8257,13 @@ 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)

include/ufs/ufs.h

+1 −0
Original line number Diff line number Diff line
@@ -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;

};



/*