scsi: ufs: Add quirk to enable host controller without hce

Some host controllers don't support host controller enable via HCE.

Link: https://lore.kernel.org/r/20200528011658.71590-4-alim.akhtar@samsung.com
Reviewed-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Seungwon Jeon <essuuj@gmail.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -3552,6 +3552,52 @@ static int ufshcd_dme_link_startup(struct ufs_hba *hba)
 			"dme-link-startup: error code %d\n", ret);
 	return ret;
 }
+/**
+ * ufshcd_dme_reset - UIC command for DME_RESET
+ * @hba: per adapter instance
+ *
+ * DME_RESET command is issued in order to reset UniPro stack.
+ * This function now deals with cold reset.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_dme_reset(struct ufs_hba *hba)
+{
+	struct uic_command uic_cmd = {0};
+	int ret;
+
+	uic_cmd.command = UIC_CMD_DME_RESET;
+
+	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+	if (ret)
+		dev_err(hba->dev,
+			"dme-reset: error code %d\n", ret);
+
+	return ret;
+}
+
+/**
+ * ufshcd_dme_enable - UIC command for DME_ENABLE
+ * @hba: per adapter instance
+ *
+ * DME_ENABLE command is issued in order to enable UniPro stack.
+ *
+ * Returns 0 on success, non-zero value on failure
+ */
+static int ufshcd_dme_enable(struct ufs_hba *hba)
+{
+	struct uic_command uic_cmd = {0};
+	int ret;
+
+	uic_cmd.command = UIC_CMD_DME_ENABLE;
+
+	ret = ufshcd_send_uic_cmd(hba, &uic_cmd);
+	if (ret)
+		dev_err(hba->dev,
+			"dme-reset: error code %d\n", ret);
+
+	return ret;
+}
 
 static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba)
 {
@@ -4276,7 +4322,7 @@ static inline void ufshcd_hba_stop(struct ufs_hba *hba)
 }
 
 /**
- * ufshcd_hba_enable - initialize the controller
+ * ufshcd_hba_execute_hce - initialize the controller
  * @hba: per adapter instance
  *
  * The controller resets itself and controller firmware initialization
@@ -4285,7 +4331,7 @@ static inline void ufshcd_hba_stop(struct ufs_hba *hba)
  *
  * Returns 0 on success, non-zero value on failure
  */
-int ufshcd_hba_enable(struct ufs_hba *hba)
+static int ufshcd_hba_execute_hce(struct ufs_hba *hba)
 {
 	int retry;
 
@@ -4333,6 +4379,32 @@ int ufshcd_hba_enable(struct ufs_hba *hba)
 
 	return 0;
 }
+
+int ufshcd_hba_enable(struct ufs_hba *hba)
+{
+	int ret;
+
+	if (hba->quirks & UFSHCI_QUIRK_BROKEN_HCE) {
+		ufshcd_set_link_off(hba);
+		ufshcd_vops_hce_enable_notify(hba, PRE_CHANGE);
+
+		/* enable UIC related interrupts */
+		ufshcd_enable_intr(hba, UFSHCD_UIC_MASK);
+		ret = ufshcd_dme_reset(hba);
+		if (!ret) {
+			ret = ufshcd_dme_enable(hba);
+			if (!ret)
+				ufshcd_vops_hce_enable_notify(hba, POST_CHANGE);
+			if (ret)
+				dev_err(hba->dev,
+					"Host controller enable failed with non-hce\n");
+		}
+	} else {
+		ret = ufshcd_hba_execute_hce(hba);
+	}
+
+	return ret;
+}
 EXPORT_SYMBOL_GPL(ufshcd_hba_enable);
 
 static int ufshcd_disable_tx_lcc(struct ufs_hba *hba, bool peer)

drivers/scsi/ufs/ufshcd.h

@@ -531,6 +531,12 @@ enum ufshcd_quirks {
 	 * that the interrupt aggregation timer and counter are reset by s/w.
 	 */
 	UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR		= 1 << 7,
+
+	/*
+	 * This quirks needs to be enabled if host controller cannot be
+	 * enabled via HCE register.
+	 */
+	UFSHCI_QUIRK_BROKEN_HCE				= 1 << 8,
 };
 
 enum ufshcd_caps {