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 |  9 +++++++++
 2 files changed, 30 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..e0e129af7c16 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,
--
2.48.1

On Tue, Jul 08, 2025 at 02:33:00AM GMT, Nitin Rawat wrote:
> 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 |  9 +++++++++
>  2 files changed, 30 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;
> +

No need to init err.

> +	/* 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");

So the error is not a hard fault and you want the driver to continue? If so, it
should be justified in commit message.

- Mani

-- 
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