scsi: ufs: allow custom delay prior to host enabling

Currently a 1 ms delay is applied before polling CONTROLLER_ENABLE
bit. This delay may not be required or can be changed in different
controllers. Make the delay as a changeable value in struct ufs_hba to
allow it customized by vendors.

Link: https://lore.kernel.org/r/20200318104016.28049-6-stanley.chu@mediatek.comReviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Can Guo <cang@codeaurora.org>
Signed-off-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -4235,7 +4235,7 @@ int ufshcd_hba_enable(struct ufs_hba *hba)
 	 * instruction might be read back.
 	 * This delay can be changed based on the controller.
 	 */
-	usleep_range(1000, 1100);
+	ufshcd_delay_us(hba->hba_enable_delay_us, 100);
 
 	/* wait for the host controller to complete initialization */
 	retry = 10;
@@ -8359,6 +8359,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 
 	hba->mmio_base = mmio_base;
 	hba->irq = irq;
+	hba->hba_enable_delay_us = 1000;
 
 	err = ufshcd_hba_init(hba);
 	if (err)

drivers/scsi/ufs/ufshcd.h

@@ -668,6 +668,7 @@ struct ufs_hba {
 	u32 eh_flags;
 	u32 intr_mask;
 	u16 ee_ctrl_mask;
+	u16 hba_enable_delay_us;
 	bool is_powered;
 	struct ufs_init_prefetch init_prefetch_data;