scsi: ufs-msm: add power management support

This patch adds the vendor specific UFS power management support for MSM
platform.

If UFS link hibernate operation is broken in HW, make sure that link
remains active and device in sleep state during the runtime suspend.
During system suspend, keep both link and device in power off state.

If UFS link hibernate operation is working properly in HW, keep the link
in hibernate state and device in sleep state during both runtime and
system suspend.

Change-Id: Ibc5be00eb9d5fd72ed116b887d835a12ed97ae78
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>

drivers/scsi/ufs/ufs-msm.c

@@ -331,9 +331,11 @@ struct msm_ufs_phy {
 	void __iomem *mmio;
 	struct clk *tx_iface_clk;
 	struct clk *rx_iface_clk;
+	bool is_iface_clk_enabled;
 	struct clk *ref_clk_src;
 	struct clk *ref_clk_parent;
 	struct clk *ref_clk;
+	bool is_ref_clk_enabled;
 	struct msm_ufs_phy_vreg vdda_pll;
 	struct msm_ufs_phy_vreg vdda_phy;
 };
@@ -975,6 +977,95 @@ out:
 	return phy;
 }
 
+/* Turn ON M-PHY RMMI interface clocks */
+static int msm_ufs_enable_phy_iface_clk(struct msm_ufs_phy *phy)
+{
+	int ret = 0;
+
+	if (phy->is_iface_clk_enabled)
+		goto out;
+
+	ret = clk_prepare_enable(phy->tx_iface_clk);
+	if (ret)
+		goto out;
+	ret = clk_prepare_enable(phy->rx_iface_clk);
+	if (ret)
+		goto disable_tx_iface_clk;
+
+	phy->is_iface_clk_enabled = true;
+
+disable_tx_iface_clk:
+	if (ret)
+		clk_disable_unprepare(phy->tx_iface_clk);
+out:
+	if (ret)
+		dev_err(phy->dev, "%s: iface_clk enable failed %d\n",
+				__func__, ret);
+	return ret;
+}
+
+/* Turn OFF M-PHY RMMI interface clocks */
+static void msm_ufs_disable_phy_iface_clk(struct msm_ufs_phy *phy)
+{
+	if (phy->is_iface_clk_enabled) {
+		clk_disable_unprepare(phy->tx_iface_clk);
+		clk_disable_unprepare(phy->rx_iface_clk);
+		phy->is_iface_clk_enabled = false;
+	}
+}
+
+static int msm_ufs_enable_phy_ref_clk(struct msm_ufs_phy *phy)
+{
+	int ret = 0;
+
+	if (phy->is_ref_clk_enabled)
+		goto out;
+
+	/*
+	 * reference clock is propagated in a daisy-chained manner from
+	 * source to phy, so ungate them at each stage.
+	 */
+	ret = clk_prepare_enable(phy->ref_clk_src);
+	if (ret) {
+		dev_err(phy->dev, "%s: ref_clk_src enable failed %d\n",
+				__func__, ret);
+		goto out;
+	}
+
+	ret = clk_prepare_enable(phy->ref_clk_parent);
+	if (ret) {
+		dev_err(phy->dev, "%s: ref_clk_parent enable failed %d\n",
+				__func__, ret);
+		goto out_disable_src;
+	}
+
+	ret = clk_prepare_enable(phy->ref_clk);
+	if (ret) {
+		dev_err(phy->dev, "%s: ref_clk enable failed %d\n",
+				__func__, ret);
+		goto out_disable_parent;
+	}
+	goto out;
+
+out_disable_parent:
+	clk_disable_unprepare(phy->ref_clk_parent);
+out_disable_src:
+	clk_disable_unprepare(phy->ref_clk_src);
+out:
+	return ret;
+}
+
+static void msm_ufs_disable_phy_ref_clk(struct msm_ufs_phy *phy)
+{
+	if (phy->is_ref_clk_enabled) {
+		clk_disable_unprepare(phy->ref_clk);
+		clk_disable_unprepare(phy->ref_clk_parent);
+		clk_disable_unprepare(phy->ref_clk_src);
+		phy->is_ref_clk_enabled = false;
+	}
+}
+
+
 static int msm_ufs_phy_cfg_vreg(struct device *dev,
 				struct msm_ufs_phy_vreg *vreg, bool on)
 {
@@ -1152,55 +1243,18 @@ static int msm_ufs_phy_power_on(struct msm_ufs_phy *phy)
 	if (err)
 		goto out_disable_phy;
 
-	/*
+	err = msm_ufs_enable_phy_ref_clk(phy);
-	 * reference clock is propagated in a daisy-chained manner from
+	if (err)
-	 * source to phy, so ungate them at each stage.
-	 */
-	err = clk_prepare_enable(phy->ref_clk_src);
-	if (err) {
-		dev_err(phy->dev, "%s: ref_clk_src enable failed %d\n",
-				__func__, err);
 		goto out_disable_pll;
-	}
 
-	err = clk_prepare_enable(phy->ref_clk_parent);
+	err = msm_ufs_enable_phy_iface_clk(phy);
-	if (err) {
+	if (err)
-		dev_err(phy->dev, "%s: ref_clk_parent enable failed %d\n",
-				__func__, err);
-		goto out_disable_src;
-	}
-
-	err = clk_prepare_enable(phy->ref_clk);
-	if (err) {
-		dev_err(phy->dev, "%s: ref_clk enable failed %d\n",
-				__func__, err);
-		goto out_disable_parent;
-	}
-
-	err = clk_prepare_enable(phy->tx_iface_clk);
-	if (err) {
-		dev_err(phy->dev, "%s: tx_iface_clk enable failed %d\n",
-				__func__, err);
 		goto out_disable_ref;
-	}
-
-	err = clk_prepare_enable(phy->rx_iface_clk);
-	if (err) {
-		dev_err(phy->dev, "%s: rx_iface_clk enable failed %d\n",
-				__func__, err);
-		goto out_disable_tx;
-	}
 
 	goto out;
 
-out_disable_tx:
-	clk_disable_unprepare(phy->tx_iface_clk);
 out_disable_ref:
-	clk_disable_unprepare(phy->ref_clk);
+	msm_ufs_disable_phy_ref_clk(phy);
-out_disable_parent:
-	clk_disable_unprepare(phy->ref_clk_parent);
-out_disable_src:
-	clk_disable_unprepare(phy->ref_clk_src);
 out_disable_pll:
 	msm_ufs_phy_disable_vreg(phy, &phy->vdda_pll);
 out_disable_phy:
@@ -1214,11 +1268,8 @@ static int msm_ufs_phy_power_off(struct msm_ufs_phy *phy)
 	writel_relaxed(0x0, phy->mmio + UFS_PHY_POWER_DOWN_CONTROL);
 	mb();
 
-	clk_disable_unprepare(phy->rx_iface_clk);
+	msm_ufs_disable_phy_iface_clk(phy);
-	clk_disable_unprepare(phy->tx_iface_clk);
+	msm_ufs_disable_phy_ref_clk(phy);
-	clk_disable_unprepare(phy->ref_clk);
-	clk_disable_unprepare(phy->ref_clk_parent);
-	clk_disable_unprepare(phy->ref_clk_src);
 
 	msm_ufs_phy_disable_vreg(phy, &phy->vdda_pll);
 	msm_ufs_phy_disable_vreg(phy, &phy->vdda_phy);
@@ -1338,6 +1389,49 @@ static int msm_ufs_link_startup_notify(struct ufs_hba *hba, bool status)
 	return 0;
 }
 
+static int msm_ufs_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	struct msm_ufs_phy *phy = hba->priv;
+	int ret = 0;
+
+	if (!phy)
+		return 0;
+
+	if (ufshcd_is_link_off(hba)) {
+		msm_ufs_phy_power_off(phy);
+		goto out;
+	}
+
+	/* M-PHY RMMI interface clocks can be turned off */
+	msm_ufs_disable_phy_iface_clk(phy);
+
+	/*
+	 * If UniPro link is not active, PHY ref_clk and main PHY analog power
+	 * can be switched off.
+	 */
+	if (!ufshcd_is_link_active(hba)) {
+		msm_ufs_disable_phy_ref_clk(phy);
+		ret = msm_ufs_phy_disable_vreg(phy, &phy->vdda_phy);
+		/*
+		 * TODO: Check if "vdda_pll" can voted off when link is hibern8
+		 * or power off state?
+		 */
+	}
+
+out:
+	return ret;
+}
+
+static int msm_ufs_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
+{
+	struct msm_ufs_phy *phy = hba->priv;
+
+	if (!phy)
+		return 0;
+
+	return msm_ufs_phy_power_on(phy);
+}
+
 #define UFS_HW_VER_MAJOR_SHFT	(28)
 #define UFS_HW_VER_MAJOR_MASK	(0x000F << UFS_HW_VER_MAJOR_SHFT)
 #define UFS_HW_VER_MINOR_SHFT	(16)
@@ -1374,7 +1468,8 @@ static void msm_ufs_advertise_quirks(struct ufs_hba *hba)
 			      | UFSHCD_QUIRK_BROKEN_VER_REG_1_1
 			      | UFSHCD_QUIRK_BROKEN_CAP_64_BIT_0
 			      | UFSHCD_QUIRK_BROKEN_DEVICE_Q_CMND
-			      | UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE);
+			      | UFSHCD_QUIRK_BROKEN_PWR_MODE_CHANGE
+			      | UFSHCD_QUIRK_BROKEN_SUSPEND);
 }
 
 /**
@@ -1404,6 +1499,30 @@ static int msm_ufs_init(struct ufs_hba *hba)
 		hba->priv = NULL;
 
 	msm_ufs_advertise_quirks(hba);
+	if (hba->quirks & UFSHCD_QUIRK_BROKEN_SUSPEND) {
+		/*
+		 * During runtime suspend and system suspend keep the device
+		 * and the link active but shut-off the system clocks.
+		 */
+		hba->rpm_lvl = UFS_PM_LVL_0;
+		hba->spm_lvl = UFS_PM_LVL_0;
+
+	} else if (hba->quirks & UFSHCD_QUIRK_BROKEN_HIBERN8) {
+		/*
+		 * During runtime suspend, keep link active but put device in
+		 * sleep state.
+		 * During system suspend, power off both link and device.
+		 */
+		hba->rpm_lvl = UFS_PM_LVL_2;
+		hba->spm_lvl = UFS_PM_LVL_4;
+	} else {
+		/*
+		 * During runtime & system suspend, put link in Hibern8 and
+		 * device in sleep.
+		 */
+		hba->rpm_lvl = UFS_PM_LVL_3;
+		hba->spm_lvl = UFS_PM_LVL_3;
+	}
 out:
 	return err;
 }
@@ -1564,6 +1683,8 @@ const struct ufs_hba_variant_ops ufs_hba_msm_vops = {
 	.exit                   = msm_ufs_exit,
 	.hce_enable_notify      = msm_ufs_hce_enable_notify,
 	.link_startup_notify    = msm_ufs_link_startup_notify,
+	.suspend		= msm_ufs_suspend,
+	.resume			= msm_ufs_resume,
 };
 EXPORT_SYMBOL(ufs_hba_msm_vops);