Enable internal clock gating for QUnipro by setting the following
attributes to 1 during host controller initialization:
- DL_VS_CLK_CFG
- PA_VS_CLK_CFG_REG
- DME_VS_CORE_CLK_CTRL.DME_HW_CGC_EN

This change is necessary to support the internal clock gating mechanism
in Qualcomm UFS host controller.

Signed-off-by: Nitin Rawat <quic_nitirawa@quicinc.com>
---
 drivers/ufs/host/ufs-qcom.c | 21 +++++++++++++++++++++
 drivers/ufs/host/ufs-qcom.h | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index dfdc52333a96..25b5f83b049c 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -558,11 +558,32 @@ static int ufs_qcom_power_up_sequence(struct ufs_hba *hba)
  */
 static void ufs_qcom_enable_hw_clk_gating(struct ufs_hba *hba)
 {
+	int err = 0;
+
+	/* Enable UTP internal clock gating */
 	ufshcd_rmwl(hba, REG_UFS_CFG2_CGC_EN_ALL, REG_UFS_CFG2_CGC_EN_ALL,
 		    REG_UFS_CFG2);

 	/* Ensure that HW clock gating is enabled before next operations */
 	ufshcd_readl(hba, REG_UFS_CFG2);
+
+	/* Enable Unipro internal clock gating */
+	err = ufshcd_dme_rmw(hba, DL_VS_CLK_CFG_MASK,
+			     DL_VS_CLK_CFG_MASK, DL_VS_CLK_CFG);
+	if (err)
+		goto out;
+
+	err = ufshcd_dme_rmw(hba, PA_VS_CLK_CFG_REG_MASK,
+			     PA_VS_CLK_CFG_REG_MASK, PA_VS_CLK_CFG_REG);
+	if (err)
+		goto out;
+
+	err = ufshcd_dme_rmw(hba, DME_VS_CORE_CLK_CTRL_DME_HW_CGC_EN,
+			     DME_VS_CORE_CLK_CTRL_DME_HW_CGC_EN,
+			     DME_VS_CORE_CLK_CTRL);
+out:
+	if (err)
+		dev_err(hba->dev, "hw clk gating enabled failed\n");
 }

 static int ufs_qcom_hce_enable_notify(struct ufs_hba *hba,
diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
index 0a5cfc2dd4f7..d8ad3cb3bd1c 100644
--- a/drivers/ufs/host/ufs-qcom.h
+++ b/drivers/ufs/host/ufs-qcom.h
@@ -24,6 +24,15 @@

 #define UFS_QCOM_LIMIT_HS_RATE		PA_HS_MODE_B

+/* bit and mask definitions for PA_VS_CLK_CFG_REG attribute */
+#define PA_VS_CLK_CFG_REG      0x9004
+#define PA_VS_CLK_CFG_REG_MASK GENMASK(8, 0)
+
+/* bit and mask definitions for DL_VS_CLK_CFG attribute */
+#define DL_VS_CLK_CFG          0xA00B
+#define DL_VS_CLK_CFG_MASK GENMASK(9, 0)
+#define DME_VS_CORE_CLK_CTRL_DME_HW_CGC_EN             BIT(9)
+
 /* QCOM UFS host controller vendor specific registers */
 enum {
 	REG_UFS_SYS1CLK_1US                 = 0xC0,
@@ -234,6 +243,32 @@ static inline void ufs_qcom_deassert_reset(struct ufs_hba *hba)
 	ufshcd_readl(hba, REG_UFS_CFG1);
 }

+/**
+ * ufshcd_dme_rmw - get modify set a dme attribute
+ * @hba - per adapter instance
+ * @mask - mask to apply on read value
+ * @val - actual value to write
+ * @attr - dme attribute
+ */
+static inline int ufshcd_dme_rmw(struct ufs_hba *hba, u32 mask,
+				 u32 val, u32 attr)
+{
+	u32 cfg = 0;
+	int err = 0;
+
+	err = ufshcd_dme_get(hba, UIC_ARG_MIB(attr), &cfg);
+	if (err)
+		goto out;
+
+	cfg &= ~mask;
+	cfg |= (val & mask);
+
+	err = ufshcd_dme_set(hba, UIC_ARG_MIB(attr), cfg);
+
+out:
+	return err;
+}
+
 /* Host controller hardware version: major.minor.step */
 struct ufs_hw_version {
 	u16 step;
--
2.48.1