scsi: ufs: ufs-mediatek: Introduce workaround for power mode change

Some MediaTek SoC chips need special flow for power mode change, especially
for chips supporting HS-G5.

Enable the workaround by setting the host-specific capability.

Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Stanley Chu <[email protected]>
Signed-off-by: CC Chou <[email protected]>
Signed-off-by: Eddie Huang <[email protected]>
Signed-off-by: Dennis Yu <[email protected]>
Signed-off-by: Peter Wang <[email protected]>
Signed-off-by: Stanley Chu <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: CC Chou

drivers/ufs/host/ufs-mediatek.c

@@ -82,6 +82,13 @@ static bool ufs_mtk_is_broken_vcc(struct ufs_hba *hba)
 	return !!(host->caps & UFS_MTK_CAP_BROKEN_VCC);
 }
 
+static bool ufs_mtk_is_pmc_via_fastauto(struct ufs_hba *hba)
+{
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+
+	return (host->caps & UFS_MTK_CAP_PMC_VIA_FASTAUTO);
+}
+
 static void ufs_mtk_cfg_unipro_cg(struct ufs_hba *hba, bool enable)
 {
 	u32 tmp;
@@ -579,6 +586,9 @@ static void ufs_mtk_init_host_caps(struct ufs_hba *hba)
 	if (of_property_read_bool(np, "mediatek,ufs-broken-vcc"))
 		host->caps |= UFS_MTK_CAP_BROKEN_VCC;
 
+	if (of_property_read_bool(np, "mediatek,ufs-pmc-via-fastauto"))
+		host->caps |= UFS_MTK_CAP_PMC_VIA_FASTAUTO;
+
 	dev_info(hba->dev, "caps: 0x%x", host->caps);
 }
 
@@ -754,6 +764,26 @@ static int ufs_mtk_init(struct ufs_hba *hba)
 	return err;
 }
 
+static bool ufs_mtk_pmc_via_fastauto(struct ufs_hba *hba,
+				     struct ufs_pa_layer_attr *dev_req_params)
+{
+	if (!ufs_mtk_is_pmc_via_fastauto(hba))
+		return false;
+
+	if (dev_req_params->hs_rate == hba->pwr_info.hs_rate)
+		return false;
+
+	if (dev_req_params->pwr_tx != FAST_MODE &&
+	    dev_req_params->gear_tx < UFS_HS_G4)
+		return false;
+
+	if (dev_req_params->pwr_rx != FAST_MODE &&
+	    dev_req_params->gear_rx < UFS_HS_G4)
+		return false;
+
+	return true;
+}
+
 static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
 				  struct ufs_pa_layer_attr *dev_max_params,
 				  struct ufs_pa_layer_attr *dev_req_params)
@@ -763,8 +793,8 @@ static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
 	int ret;
 
 	ufshcd_init_pwr_dev_param(&host_cap);
-	host_cap.hs_rx_gear = UFS_HS_G4;
-	host_cap.hs_tx_gear = UFS_HS_G4;
+	host_cap.hs_rx_gear = UFS_HS_G5;
+	host_cap.hs_tx_gear = UFS_HS_G5;
 
 	ret = ufshcd_get_pwr_dev_param(&host_cap,
 				       dev_max_params,
@@ -774,6 +804,32 @@ static int ufs_mtk_pre_pwr_change(struct ufs_hba *hba,
 			__func__);
 	}
 
+	if (ufs_mtk_pmc_via_fastauto(hba, dev_req_params)) {
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXTERMINATION), true);
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXGEAR), UFS_HS_G1);
+
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXTERMINATION), true);
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_RXGEAR), UFS_HS_G1);
+
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVETXDATALANES),
+			       dev_req_params->lane_tx);
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_ACTIVERXDATALANES),
+			       dev_req_params->lane_rx);
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_HSSERIES),
+			       dev_req_params->hs_rate);
+
+		ufshcd_dme_set(hba, UIC_ARG_MIB(PA_TXHSADAPTTYPE),
+			       PA_NO_ADAPT);
+
+		ret = ufshcd_uic_change_pwr_mode(hba,
+					FASTAUTO_MODE << 4 | FASTAUTO_MODE);
+
+		if (ret) {
+			dev_err(hba->dev, "%s: HSG1B FASTAUTO failed ret=%d\n",
+				__func__, ret);
+		}
+	}
+
 	if (host->hw_ver.major >= 3) {
 		ret = ufshcd_dme_configure_adapt(hba,
 					   dev_req_params->gear_tx,

drivers/ufs/host/ufs-mediatek.h

@@ -108,6 +108,7 @@ enum ufs_mtk_host_caps {
 	UFS_MTK_CAP_VA09_PWR_CTRL              = 1 << 1,
 	UFS_MTK_CAP_DISABLE_AH8                = 1 << 2,
 	UFS_MTK_CAP_BROKEN_VCC                 = 1 << 3,
+	UFS_MTK_CAP_PMC_VIA_FASTAUTO           = 1 << 6,
 };
 
 struct ufs_mtk_crypt_cfg {

include/ufs/unipro.h

@@ -228,6 +228,7 @@ enum ufs_hs_gear_tag {
 	UFS_HS_G2,		/* HS Gear 2 */
 	UFS_HS_G3,		/* HS Gear 3 */
 	UFS_HS_G4,		/* HS Gear 4 */
+	UFS_HS_G5		/* HS Gear 5 */
 };
 
 enum ufs_unipro_ver {