[PATCH v2 3/6] scsi: ufs-mediatek: introduce reference clock control

@@ -22,6 +22,9 @@
 	arm_smccc_smc(MTK_SIP_UFS_CONTROL, \
 		      cmd, val, 0, 0, 0, 0, 0, &(res))
 
+#define ufs_mtk_ref_clk_notify(on, res) \
+	ufs_mtk_smc(UFS_MTK_SIP_REF_CLK_NOTIFICATION, on, res)
+
 #define ufs_mtk_device_reset_ctrl(high, res) \
 	ufs_mtk_smc(UFS_MTK_SIP_DEVICE_RESET, high, res)
 

@@ -90,6 +93,49 @@ static int ufs_mtk_bind_mphy(struct ufs_hba *hba)
 	return err;
 }
 
+static int ufs_mtk_setup_ref_clk(struct ufs_hba *hba, bool on)
+{
+	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
+	struct arm_smccc_res res;
+	unsigned long timeout;
+	u32 value;
+
+	if (host->ref_clk_enabled == on)
+		return 0;
+
+	if (on) {
+		ufs_mtk_ref_clk_notify(on, res);
+		ufshcd_writel(hba, REFCLK_REQUEST, REG_UFS_REFCLK_CTRL);
+	} else {
+		ufshcd_writel(hba, REFCLK_RELEASE, REG_UFS_REFCLK_CTRL);
+	}
+
+	/* Wait for ack */
+	timeout = jiffies + msecs_to_jiffies(REFCLK_REQ_TIMEOUT_MS);
+	do {
+		value = ufshcd_readl(hba, REG_UFS_REFCLK_CTRL);
+
+		/* Wait until ack bit equals to req bit */
+		if (((value & REFCLK_ACK) >> 1) == (value & REFCLK_REQUEST))
+			goto out;
+
+		usleep_range(100, 200);
+	} while (time_before(jiffies, timeout));
+
+	dev_err(hba->dev, "missing ack of refclk req, reg: 0x%x\n", value);
+
+	ufs_mtk_ref_clk_notify(host->ref_clk_enabled, res);
+
+	return -ETIMEDOUT;
+
+out:
+	host->ref_clk_enabled = on;
+	if (!on)
+		ufs_mtk_ref_clk_notify(on, res);
+
+	return 0;
+}
+
 /**
  * ufs_mtk_setup_clocks - enables/disable clocks
  * @hba: host controller instance

@@ -114,12 +160,16 @@ static int ufs_mtk_setup_clocks(struct ufs_hba *hba, bool on,
 
 	switch (status) {
 	case PRE_CHANGE:
-		if (!on)
+		if (!on) {
+			ufs_mtk_setup_ref_clk(hba, on);
 			ret = phy_power_off(host->mphy);
+		}
 		break;
 	case POST_CHANGE:
-		if (on)
+		if (on) {
 			ret = phy_power_on(host->mphy);
+			ufs_mtk_setup_ref_clk(hba, on);
+		}
 		break;
 	}
 

@@ -305,8 +355,10 @@ static int ufs_mtk_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 
-	if (ufshcd_is_link_hibern8(hba))
+	if (ufshcd_is_link_hibern8(hba)) {
 		phy_power_off(host->mphy);
+		ufs_mtk_setup_ref_clk(hba, false);
+	}
 
 	return 0;
 }

@@ -315,8 +367,10 @@ static int ufs_mtk_resume(struct ufs_hba *hba, enum ufs_pm_op pm_op)
 {
 	struct ufs_mtk_host *host = ufshcd_get_variant(hba);
 
-	if (ufshcd_is_link_hibern8(hba))
+	if (ufshcd_is_link_hibern8(hba)) {
+		ufs_mtk_setup_ref_clk(hba, true);
 		phy_power_on(host->mphy);
+	}
 
 	return 0;
 }

@@ -9,6 +9,22 @@
 #include <linux/bitops.h>
 #include <linux/soc/mediatek/mtk_sip_svc.h>
 
+/*
+ * Vendor specific UFSHCI Registers
+ */
+#define REG_UFS_REFCLK_CTRL         0x144
+
+/*
+ * Ref-clk control
+ *
+ * Values for register REG_UFS_REFCLK_CTRL
+ */
+#define REFCLK_RELEASE              0x0
+#define REFCLK_REQUEST              BIT(0)
+#define REFCLK_ACK                  BIT(1)
+
+#define REFCLK_REQ_TIMEOUT_MS       3
+
 /*
  * Vendor specific pre-defined parameters
  */

@@ -35,8 +51,9 @@
 /*
  * SiP commands
  */
-#define MTK_SIP_UFS_CONTROL         MTK_SIP_SMC_CMD(0x276)
-#define UFS_MTK_SIP_DEVICE_RESET    BIT(1)
+#define MTK_SIP_UFS_CONTROL               MTK_SIP_SMC_CMD(0x276)
+#define UFS_MTK_SIP_DEVICE_RESET          BIT(1)
+#define UFS_MTK_SIP_REF_CLK_NOTIFICATION  BIT(3)
 
 /*
  * VS_DEBUGCLOCKENABLE

@@ -57,6 +74,7 @@ enum {
 struct ufs_mtk_host {
 	struct ufs_hba *hba;
 	struct phy *mphy;
+	bool ref_clk_enabled;
 };
 
 #endif /* !_UFS_MEDIATEK_H */