[PATCH V6 2/6] scsi: ufs: qcom: Configure PA_VS_CORE_CLK_40NS_CYCLES

[Nitin Rawat]

Configure PA_VS_CORE_CLK_40NS_CYCLES with frequency of unipro core clk
for Qualcomm UFS controller V4.0 and onwards to align with the hardware
specification.

Co-developed-by: Naveen Kumar Goud Arepalli <quic_narepall@xxxxxxxxxxx>
Signed-off-by: Naveen Kumar Goud Arepalli <quic_narepall@xxxxxxxxxxx>
Signed-off-by: Nitin Rawat <quic_nitirawa@xxxxxxxxxxx>
---
 drivers/ufs/host/ufs-qcom.c | 47 ++++++++++++++++++++++++++++---------
 drivers/ufs/host/ufs-qcom.h |  2 ++
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index fe36003faaa8..018e391c276e 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -93,8 +93,9 @@ static const struct __ufs_qcom_bw_table {
 static struct ufs_qcom_host *ufs_qcom_hosts[MAX_UFS_QCOM_HOSTS];

 static void ufs_qcom_get_default_testbus_cfg(struct ufs_qcom_host *host);
-static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
-						       u32 clk_cycles);
+static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba,
+						       u32 clk_cycles,
+						       u32 clk_40ns_cycles);

 static struct ufs_qcom_host *rcdev_to_ufs_host(struct reset_controller_dev *rcd)
 {
@@ -690,8 +691,8 @@ static int ufs_qcom_link_startup_notify(struct ufs_hba *hba,
 			 * set unipro core clock cycles to 150 & clear clock
 			 * divider
 			 */
-			err = ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(hba,
-									  150);
+			err = ufs_qcom_set_core_clk_ctrl(hba,
+									  150, 6);

 		/*
 		 * Some UFS devices (and may be host) have issues if LCC is
@@ -1295,12 +1296,12 @@ static void ufs_qcom_exit(struct ufs_hba *hba)
 	phy_power_off(host->generic_phy);
 	phy_exit(host->generic_phy);
 }
-
-static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
-						       u32 cycles_in_1us)
+static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba,
+					u32 cycles_in_1us,
+					u32 cycles_in_40ns)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	u32 core_clk_ctrl_reg;
+	u32 core_clk_ctrl_reg, reg;
 	int ret;

 	ret = ufshcd_dme_get(hba,
@@ -1325,9 +1326,33 @@ static int ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(struct ufs_hba *hba,
 	/* Clear CORE_CLK_DIV_EN */
 	core_clk_ctrl_reg &= ~DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT;

-	return ufshcd_dme_set(hba,
+	err = ufshcd_dme_set(hba,
 			    UIC_ARG_MIB(DME_VS_CORE_CLK_CTRL),
 			    core_clk_ctrl_reg);
+	/*
+	 * UFS host controller V4.0.0 onwards needs to program
+	 * PA_VS_CORE_CLK_40NS_CYCLES attribute per programmed
+	 * frequency of unipro core clk of UFS host controller.
+	 */
+	if (!err && (host->hw_ver.major >= 4)) {
+		if (cycles_in_40ns > PA_VS_CORE_CLK_40NS_CYCLES_MASK)
+			return -EINVAL;
+
+		err = ufshcd_dme_get(hba,
+				     UIC_ARG_MIB(PA_VS_CORE_CLK_40NS_CYCLES),
+				     &reg);
+		if (err)
+			return err;
+
+		reg &= ~PA_VS_CORE_CLK_40NS_CYCLES_MASK;
+		reg |= cycles_in_40ns;
+
+		err = ufshcd_dme_set(hba,
+				     UIC_ARG_MIB(PA_VS_CORE_CLK_40NS_CYCLES),
+				     reg);
+	}
+
+	return err;
 }

 static int ufs_qcom_clk_scale_up_pre_change(struct ufs_hba *hba)
@@ -1344,7 +1369,7 @@ static int ufs_qcom_clk_scale_up_post_change(struct ufs_hba *hba)
 		return 0;

 	/* set unipro core clock cycles to 150 and clear clock divider */
-	return ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(hba, 150);
+	return ufs_qcom_set_core_clk_ctrl(hba, 150, 6);
 }

 static int ufs_qcom_clk_scale_down_pre_change(struct ufs_hba *hba)
@@ -1380,7 +1405,7 @@ static int ufs_qcom_clk_scale_down_post_change(struct ufs_hba *hba)
 		return 0;

 	/* set unipro core clock cycles to 75 and clear clock divider */
-	return ufs_qcom_set_dme_vs_core_clk_ctrl_clear_div(hba, 75);
+	return ufs_qcom_set_core_clk_ctrl(hba, 75, 3);
 }

 static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
diff --git a/drivers/ufs/host/ufs-qcom.h b/drivers/ufs/host/ufs-qcom.h
index 8a9d3dbec297..d81bf1a1b77a 100644
--- a/drivers/ufs/host/ufs-qcom.h
+++ b/drivers/ufs/host/ufs-qcom.h
@@ -132,6 +132,8 @@ enum {
 #define CLK_1US_CYCLES_MASK_V4				GENMASK(27, 16)
 #define CLK_1US_CYCLES_MASK				GENMASK(7, 0)
 #define DME_VS_CORE_CLK_CTRL_CORE_CLK_DIV_EN_BIT	BIT(8)
+#define PA_VS_CORE_CLK_40NS_CYCLES			0x9007
+#define PA_VS_CORE_CLK_40NS_CYCLES_MASK			GENMASK(6, 0)

 static inline void
 ufs_qcom_get_controller_revision(struct ufs_hba *hba,
--
2.17.1