scsi: ufs: ufs-qcom: Add support for reinitializing the UFS device

Starting from Qualcomm UFS version 4, the UFS device needs to be
reinitialized after switching to maximum gear by the UFS core. Hence, add
support for it by enabling the UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH
quirk, implementing reinit_notify() callback and using the agreed gear
speed for setting the PHY mode.
Suggested-by: Can Guo <quic_cang@quicinc.com>
Tested-by: Andrew Halaney <ahalaney@redhat.com> # Qdrive3/sa8540p-ride
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/ufs/host/ufs-qcom.c

@@ -293,7 +293,6 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	struct phy *phy = host->generic_phy;
 	int ret;
-	bool is_rate_B = UFS_QCOM_LIMIT_HS_RATE == PA_HS_MODE_B;
 
 	/* Reset UFS Host Controller and PHY */
 	ret = ufs_qcom_host_reset(hba);
@@ -301,9 +300,6 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
 		dev_warn(hba->dev, "%s: host reset returned %d\n",
 				  __func__, ret);
 
-	if (is_rate_B)
-		phy_set_mode(phy, PHY_MODE_UFS_HS_B);
-
 	/* phy initialization - calibrate the phy */
 	ret = phy_init(phy);
 	if (ret) {
@@ -312,6 +308,8 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
 		return ret;
 	}
 
+	phy_set_mode_ext(phy, PHY_MODE_UFS_HS_B, host->hs_gear);
+
 	/* power on phy - start serdes and phy's power and clocks */
 	ret = phy_power_on(phy);
 	if (ret) {
@@ -714,6 +712,9 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 			return ret;
 		}
 
+		/* Use the agreed gear */
+		host->hs_gear = dev_req_params->gear_tx;
+
 		/* enable the device ref clock before changing to HS mode */
 		if (!ufshcd_is_hs_mode(&hba->pwr_info) &&
 			ufshcd_is_hs_mode(dev_req_params))
@@ -827,6 +828,9 @@ static void ufs_qcom_advertise_quirks(struct ufs_hba *hba)
 				| UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE
 				| UFSHCD_QUIRK_BROKEN_PA_RXHSUNTERMCAP);
 	}
+
+	if (host->hw_ver.major > 0x3)
+		hba->quirks |= UFSHCD_QUIRK_REINIT_AFTER_MAX_GEAR_SWITCH;
 }
 
 static void ufs_qcom_set_caps(struct ufs_hba *hba)
@@ -1034,6 +1038,12 @@ static int ufs_qcom_init(struct ufs_hba *hba)
 		dev_warn(dev, "%s: failed to configure the testbus %d\n",
 				__func__, err);
 
+	/*
+	 * Power up the PHY using the minimum supported gear (UFS_HS_G2).
+	 * Switching to max gear will be performed during reinit if supported.
+	 */
+	host->hs_gear = UFS_HS_G2;
+
 	return 0;
 
 out_variant_clear:
@@ -1377,6 +1387,13 @@ static void ufs_qcom_config_scaling_param(struct ufs_hba *hba,
 }
 #endif
 
+static void ufs_qcom_reinit_notify(struct ufs_hba *hba)
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	phy_power_off(host->generic_phy);
+}
+
 /*
  * struct ufs_hba_qcom_vops - UFS QCOM specific variant operations
  *
@@ -1400,6 +1417,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.device_reset		= ufs_qcom_device_reset,
 	.config_scaling_param = ufs_qcom_config_scaling_param,
 	.program_key		= ufs_qcom_ice_program_key,
+	.reinit_notify		= ufs_qcom_reinit_notify,
 };
 
 /**

drivers/ufs/host/ufs-qcom.h

@@ -206,6 +206,8 @@ struct ufs_qcom_host {
 	struct reset_controller_dev rcdev;
 
 	struct gpio_desc *device_reset;
+
+	u32 hs_gear;
 };
 
 static inline u32