scsi: ufs: mediatek: TX skew fix

Fix Mediatek TX skew issue by checking dts setting and vendor/model. Then
set PA_TACTIVATE to 8.
Signed-off-by: Peter Wang <peter.wang@mediatek.com>
Acked-by: Chun-Hung Wu <Chun-Hung.Wu@mediatek.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Link: https://lore.kernel.org/r/20240315083448.7185-3-peter.wang@mediatek.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/host/ufs-mediatek.c

@@ -118,6 +118,13 @@ static bool ufs_mtk_is_pmc_via_fastauto(struct ufs_hba *hba)
 	return !!(host->caps & UFS_MTK_CAP_PMC_VIA_FASTAUTO);
 }
 
+static bool ufs_mtk_is_tx_skew_fix(struct ufs_hba *hba)
+{
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+	return (host->caps & UFS_MTK_CAP_TX_SKEW_FIX);
+}
+
 static bool ufs_mtk_is_allow_vccqx_lpm(struct ufs_hba *hba)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
@@ -629,6 +636,9 @@ static void ufs_mtk_init_host_caps(struct ufs_hba *hba)
 	if (of_property_read_bool(np, "mediatek,ufs-pmc-via-fastauto"))
 		host->caps |= UFS_MTK_CAP_PMC_VIA_FASTAUTO;
 
+	if (of_property_read_bool(np, "mediatek,ufs-tx-skew-fix"))
+		host->caps |= UFS_MTK_CAP_TX_SKEW_FIX;
+
 	dev_info(hba->dev, "caps: 0x%x", host->caps);
 }
 
@@ -1455,6 +1465,17 @@ static int ufs_mtk_apply_dev_quirks(struct ufs_hba *hba)
 	if (mid == UFS_VENDOR_SAMSUNG) {
 		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TACTIVATE), 6);
 		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HIBERN8TIME), 10);
+	} else if (mid == UFS_VENDOR_MICRON) {
+		/* Only for the host which have TX skew issue */
+		if (ufs_mtk_is_tx_skew_fix(hba) &&
+			(STR_PRFX_EQUAL("MT128GBCAV2U31", dev_info->model) ||
+			STR_PRFX_EQUAL("MT256GBCAV4U31", dev_info->model) ||
+			STR_PRFX_EQUAL("MT512GBCAV8U31", dev_info->model) ||
+			STR_PRFX_EQUAL("MT256GBEAX4U40", dev_info->model) ||
+			STR_PRFX_EQUAL("MT512GAYAX4U40", dev_info->model) ||
+			STR_PRFX_EQUAL("MT001TAYAX8U40", dev_info->model))) {
+			ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TACTIVATE), 8);
+		}
 	}
 
 	/*

drivers/ufs/host/ufs-mediatek.h

@@ -142,6 +142,7 @@ enum ufs_mtk_host_caps {
 	 */
 	UFS_MTK_CAP_ALLOW_VCCQX_LPM            = 1 << 5,
 	UFS_MTK_CAP_PMC_VIA_FASTAUTO           = 1 << 6,
+	UFS_MTK_CAP_TX_SKEW_FIX                = 1 << 7,
 };
 
 struct ufs_mtk_crypt_cfg {