scsi: ufs: core: Pass the clock scaling timeout as an argument

Prepare for adding an additional ufshcd_clock_scaling_prepare() call with a
different timeout.
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/core/ufshcd.c

@@ -1121,6 +1121,12 @@ static u32 ufshcd_pending_cmds(struct ufs_hba *hba)
 	return pending;
 }
 
+/*
+ * Wait until all pending SCSI commands and TMFs have finished or the timeout
+ * has expired.
+ *
+ * Return: 0 upon success; -EBUSY upon timeout.
+ */
 static int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba,
 					u64 wait_timeout_us)
 {
@@ -1225,9 +1231,14 @@ static int ufshcd_scale_gear(struct ufs_hba *hba, bool scale_up)
 	return ret;
 }
 
-static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
+/*
+ * Wait until all pending SCSI commands and TMFs have finished or the timeout
+ * has expired.
+ *
+ * Return: 0 upon success; -EBUSY upon timeout.
+ */
+static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us)
 {
-	#define DOORBELL_CLR_TOUT_US		(1000 * 1000) /* 1 sec */
 	int ret = 0;
 	/*
 	 * make sure that there are no outstanding requests when
@@ -1237,7 +1248,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba)
 	down_write(&hba->clk_scaling_lock);
 
 	if (!hba->clk_scaling.is_allowed ||
-	    ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US)) {
+	    ufshcd_wait_for_doorbell_clr(hba, timeout_us)) {
 		ret = -EBUSY;
 		up_write(&hba->clk_scaling_lock);
 		ufshcd_scsi_unblock_requests(hba);
@@ -1275,7 +1286,7 @@ static int ufshcd_devfreq_scale(struct ufs_hba *hba, bool scale_up)
 	int ret = 0;
 	bool is_writelock = true;
 
-	ret = ufshcd_clock_scaling_prepare(hba);
+	ret = ufshcd_clock_scaling_prepare(hba, 1 * USEC_PER_SEC);
 	if (ret)
 		return ret;