scsi: ufs: host: mediatek: Add DDR_EN setting

On MT6989 and later platforms, control of DDR_EN has been switched from
SPM to EMI. To prevent abnormal access to DRAM, it is necessary to wait
for 'ddren_ack' or assert 'ddren_urgent' after sending 'ddren_req'.

Introduce the DDR_EN configuration in the UFS initialization flow,
utilizing the assertion of 'ddren_urgent' to maintain performance.

Signed-off-by: Naomi Chu <naomi.chu@mediatek.com>
Link: https://lore.kernel.org/r/20250722030841.1998783-3-peter.wang@mediatek.com
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Chun-Hung Wu <chun-hung.wu@mediatek.com>
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: Naomi Chu

drivers/ufs/host/ufs-mediatek.c

@@ -267,6 +267,13 @@ static int ufs_mtk_hce_enable_notify(struct ufs_hba *hba,
 		ufshcd_writel(hba,
 			      ufshcd_readl(hba, REG_UFS_XOUFS_CTRL) | 0x80,
 			      REG_UFS_XOUFS_CTRL);
+
+		/* DDR_EN setting */
+		if (host->ip_ver >= IP_VER_MT6989) {
+			ufshcd_rmwl(hba, UFS_MASK(0x7FFF, 8),
+				0x453000, REG_UFS_MMIO_OPT_CTRL_0);
+		}
+
 	}
 
 	return 0;

drivers/ufs/host/ufs-mediatek.h

@@ -192,4 +192,16 @@ struct ufs_mtk_host {
 /* MTK RTT support number */
 #define MTK_MAX_NUM_RTT 2
 
+/* UFSHCI MTK ip version value */
+enum {
+	/* UFSHCI 3.1 */
+	IP_VER_MT6878    = 0x10420200,
+
+	/* UFSHCI 4.0 */
+	IP_VER_MT6897    = 0x10440000,
+	IP_VER_MT6989    = 0x10450000,
+
+	IP_VER_NONE      = 0xFFFFFFFF
+};
+
 #endif /* !_UFS_MEDIATEK_H */