[PATCH v7 3/7] scsi: ufs: introduce common and flexible delay function

[Stanley Chu]

Introduce a common delay function to provide flexible way for users
to take choices of udelay and usleep_range into consideration according
to the required delay time.

Signed-off-by: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>
Reviewed-by: Can Guo <cang@xxxxxxxxxxxxxx>
---
 drivers/scsi/ufs/ufshcd.c | 12 ++++++++++++
 drivers/scsi/ufs/ufshcd.h |  1 +
 2 files changed, 13 insertions(+)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 314e808b0d4e..a42a84164dec 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -597,6 +597,18 @@ static void ufshcd_print_pwr_info(struct ufs_hba *hba)
 		 hba->pwr_info.hs_rate);
 }
 
+void ufshcd_delay_us(unsigned long us, unsigned long tolerance)
+{
+	if (!us)
+		return;
+
+	if (us < 10)
+		udelay(us);
+	else
+		usleep_range(us, us + tolerance);
+}
+EXPORT_SYMBOL_GPL(ufshcd_delay_us);
+
 /*
  * ufshcd_wait_for_register - wait for register value to change
  * @hba - per-adapter interface
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 52425371082a..9a14ff3d5f8b 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -792,6 +792,7 @@ int ufshcd_init(struct ufs_hba * , void __iomem * , unsigned int);
 int ufshcd_make_hba_operational(struct ufs_hba *hba);
 void ufshcd_remove(struct ufs_hba *);
 int ufshcd_uic_hibern8_exit(struct ufs_hba *hba);
+void ufshcd_delay_us(unsigned long us, unsigned long tolerance);
 int ufshcd_wait_for_register(struct ufs_hba *hba, u32 reg, u32 mask,
 				u32 val, unsigned long interval_us,
 				unsigned long timeout_ms, bool can_sleep);
-- 
2.18.0