linux-kernel - [PATCH RESEND 1/2] scsi: ufs: Enable hibern8 interrupt only during manual hibern8 in Cadence UFS.

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Date:   Tue, 19 Nov 2019 08:04:41 +0100
From:   sheebab <sheebab@...ence.com>
To:     <alim.akhtar@...sung.com>, <avri.altman@....com>,
        <pedrom.sousa@...opsys.com>, <jejb@...ux.ibm.com>,
        <martin.petersen@...cle.com>, <stanley.chu@...iatek.com>,
        <beanhuo@...ron.com>, <yuehaibing@...wei.com>,
        <linux-scsi@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <vigneshr@...com>, <linux-block@...r.kernel.org>
CC:     <rafalc@...ence.com>, <mparab@...ence.com>,
        sheebab <sheebab@...ence.com>
Subject: [PATCH RESEND 1/2] scsi: ufs: Enable hibern8 interrupt only during manual hibern8 in Cadence UFS.

Auto hibern8 causes false interrupt assertion.
To overcome this, disable hibern8 interrupt during initialization
and Enable/Disable hibern8 interrupt during manual hibern8 Entry/Exit.

Signed-off-by: sheebab <sheebab@...ence.com>
---
 drivers/scsi/ufs/cdns-pltfrm.c | 75 ++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 72 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c
index b2af04c..adbbd60 100644
--- a/drivers/scsi/ufs/cdns-pltfrm.c
+++ b/drivers/scsi/ufs/cdns-pltfrm.c
@@ -21,6 +21,32 @@
 #define CDNS_UFS_REG_PHY_XCFGD1	0x113C
 
 /**
+ * cdns_ufs_enable_intr - enable interrupts
+ * @hba: per adapter instance
+ * @intrs: interrupt bits
+ */
+static void cdns_ufs_enable_intr(struct ufs_hba *hba, u32 intrs)
+{
+	u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+
+	set = set | intrs;
+	ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
+}
+
+/**
+ * cdns_ufs_disable_intr - disable interrupts
+ * @hba: per adapter instance
+ * @intrs: interrupt bits
+ */
+static void cdns_ufs_disable_intr(struct ufs_hba *hba, u32 intrs)
+{
+	u32 set = ufshcd_readl(hba, REG_INTERRUPT_ENABLE);
+
+	set = set & ~intrs;
+	ufshcd_writel(hba, set, REG_INTERRUPT_ENABLE);
+}
+
+/**
  * Sets HCLKDIV register value based on the core_clk
  * @hba: host controller instance
  *
@@ -71,10 +97,51 @@ static int cdns_ufs_set_hclkdiv(struct ufs_hba *hba)
 static int cdns_ufs_hce_enable_notify(struct ufs_hba *hba,
 				      enum ufs_notify_change_status status)
 {
-	if (status != PRE_CHANGE)
-		return 0;
+	int err = 0;
+
+	switch (status) {
+	case PRE_CHANGE:
+		err = cdns_ufs_set_hclkdiv(hba);
+		break;
+	case POST_CHANGE:
+		/**
+		 * Hibern8 interrupts(UHESE, UHXSE) disabled
+		 * during initialization.
+		 */
+		cdns_ufs_disable_intr(hba, UFSHCD_UIC_HIBERN8_MASK);
+		break;
+	default:
+		dev_err(hba->dev, "%s: invalid status %d\n", __func__, status);
+		err = -EINVAL;
+		break;
+	}
+	return err;
+}
 
-	return cdns_ufs_set_hclkdiv(hba);
+/**
+ * Called around hibern8 enter/exit.
+ * @hba: host controller instance
+ * @cmd: UIC Command
+ * @status: notify stage (pre, post change)
+ *
+ */
+static void cdns_ufs_hibern8_notify(struct ufs_hba *hba, enum uic_cmd_dme cmd,
+				    enum ufs_notify_change_status status)
+{
+	if (status == PRE_CHANGE && cmd == UIC_CMD_DME_HIBER_ENTER) {
+		/**
+		 * Hibern8 interrupts(UHESE, UHXSE) enabled
+		 * before manual hibernate entry.
+		 */
+		cdns_ufs_enable_intr(hba, UFSHCD_UIC_HIBERN8_MASK);
+	}
+	if (status == POST_CHANGE && cmd == UIC_CMD_DME_HIBER_EXIT) {
+		/**
+		 * Hibern8 interrupts(UHESE, UHXSE) disabled
+		 * after manual hibern8 exit.
+		 */
+		cdns_ufs_disable_intr(hba, UFSHCD_UIC_HIBERN8_MASK);
+	}
 }
 
 /**
@@ -140,6 +207,7 @@ static const struct ufs_hba_variant_ops cdns_ufs_pltfm_hba_vops = {
 	.name = "cdns-ufs-pltfm",
 	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 	.link_startup_notify = cdns_ufs_link_startup_notify,
+	.hibern8_notify = cdns_ufs_hibern8_notify,
 };
 
 static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
@@ -148,6 +216,7 @@ static const struct ufs_hba_variant_ops cdns_ufs_m31_16nm_pltfm_hba_vops = {
 	.hce_enable_notify = cdns_ufs_hce_enable_notify,
 	.link_startup_notify = cdns_ufs_link_startup_notify,
 	.phy_initialization = cdns_ufs_m31_16nm_phy_initialization,
+	.hibern8_notify = cdns_ufs_hibern8_notify,
 };
 
 static const struct of_device_id cdns_ufs_of_match[] = {
-- 
2.7.4