scsi: ufs: qcom: Configure SYS1CLK_1US_REG for UFS V4 and above

SYS1CLK_1US represents the required number of system 1-clock cycles for one
microsecond. UFS Host Controller V4.0 and above mandates to write
SYS1CLK_1US_REG register and also these timer configuration needs to be
called from clk scaling pre ops as per HPG.

Refactor ufs_qcom_cfg_timers and add the below code support to align
with HPG.

a)Configure SYS1CLK_1US_REG for UFS V4 and above.
b)Introduce a new argument is_pre_scale_up for ufs_qcom_cfg_timers
to configure SYS1CLK_1US for max freq during prescale and link startup
condition.
c)Move ufs_qcom_cfg_timers from clk scaling post change ops
to clk scaling pre change ops.

Co-developed-by: Naveen Kumar Goud Arepalli <[email protected]>
Signed-off-by: Naveen Kumar Goud Arepalli <[email protected]>
Signed-off-by: Nitin Rawat <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Can Guo <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>

Author: Nitin Rawat

drivers/ufs/host/ufs-qcom.c

@@ -527,11 +527,20 @@ static int ufs_qcom_hce_enable_notify(struct ufs_hba *hba,
 	return err;
 }
 
-/*
+/**
+ * ufs_qcom_cfg_timers - Configure ufs qcom cfg timers
+ *
+ * @hba: host controller instance
+ * @gear: Current operating gear
+ * @hs: current power mode
+ * @rate: current operating rate (A or B)
+ * @update_link_startup_timer: indicate if link_start ongoing
+ * @is_pre_scale_up: flag to check if pre scale up condition.
  * Return: zero for success and non-zero in case of a failure.
  */
 static int ufs_qcom_cfg_timers(struct ufs_hba *hba, u32 gear,
-			       u32 hs, u32 rate, bool update_link_startup_timer)
+			       u32 hs, u32 rate, bool update_link_startup_timer,
+			       bool is_pre_scale_up)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
 	struct ufs_clk_info *clki;
@@ -562,11 +571,14 @@ static int ufs_qcom_cfg_timers(struct ufs_hba *hba, u32 gear,
 	/*
 	 * The Qunipro controller does not use following registers:
 	 * SYS1CLK_1US_REG, TX_SYMBOL_CLK_1US_REG, CLK_NS_REG &
-	 * UFS_REG_PA_LINK_STARTUP_TIMER
-	 * But UTP controller uses SYS1CLK_1US_REG register for Interrupt
+	 * UFS_REG_PA_LINK_STARTUP_TIMER.
+	 * However UTP controller uses SYS1CLK_1US_REG register for Interrupt
 	 * Aggregation logic.
-	*/
-	if (ufs_qcom_cap_qunipro(host) && !ufshcd_is_intr_aggr_allowed(hba))
+	 * It is mandatory to write SYS1CLK_1US_REG register on UFS host
+	 * controller V4.0.0 onwards.
+	 */
+	if (host->hw_ver.major < 4 && ufs_qcom_cap_qunipro(host) &&
+	    !ufshcd_is_intr_aggr_allowed(hba))
 		return 0;
 
 	if (gear == 0) {
@@ -575,8 +587,14 @@ static int ufs_qcom_cfg_timers(struct ufs_hba *hba, u32 gear,
 	}
 
 	list_for_each_entry(clki, &hba->clk_list_head, list) {
-		if (!strcmp(clki->name, "core_clk"))
-			core_clk_rate = clk_get_rate(clki->clk);
+		if (!strcmp(clki->name, "core_clk")) {
+			if (is_pre_scale_up)
+				core_clk_rate = clki->max_freq;
+			else
+				core_clk_rate = clk_get_rate(clki->clk);
+			break;
+		}
+
 	}
 
 	/* If frequency is smaller than 1MHz, set to 1MHz */
@@ -678,7 +696,7 @@ static int ufs_qcom_link_startup_notify(struct ufs_hba *hba,
 	switch (status) {
 	case PRE_CHANGE:
 		if (ufs_qcom_cfg_timers(hba, UFS_PWM_G1, SLOWAUTO_MODE,
-					0, true)) {
+					0, true, false)) {
 			dev_err(hba->dev, "%s: ufs_qcom_cfg_timers() failed\n",
 				__func__);
 			return -EINVAL;
@@ -922,7 +940,7 @@ static int ufs_qcom_pwr_change_notify(struct ufs_hba *hba,
 	case POST_CHANGE:
 		if (ufs_qcom_cfg_timers(hba, dev_req_params->gear_rx,
 					dev_req_params->pwr_rx,
-					dev_req_params->hs_rate, false)) {
+					dev_req_params->hs_rate, false, false)) {
 			dev_err(hba->dev, "%s: ufs_qcom_cfg_timers() failed\n",
 				__func__);
 			/*
@@ -1418,10 +1436,22 @@ static int ufs_qcom_set_core_clk_ctrl(struct ufs_hba *hba, bool is_scale_up)
 static int ufs_qcom_clk_scale_up_pre_change(struct ufs_hba *hba)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+	struct ufs_pa_layer_attr *attr = &host->dev_req_params;
+	int ret;
 
 	if (!ufs_qcom_cap_qunipro(host))
 		return 0;
 
+	if (attr) {
+		ret = ufs_qcom_cfg_timers(hba, attr->gear_rx,
+					attr->pwr_rx, attr->hs_rate,
+					false, true);
+		if (ret) {
+			dev_err(hba->dev, "%s ufs cfg timer failed\n",
+						__func__);
+			return ret;
+		}
+	}
 	/* set unipro core clock attributes and clear clock divider */
 	return ufs_qcom_set_core_clk_ctrl(hba, true);
 }
@@ -1471,7 +1501,6 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
 		bool scale_up, enum ufs_notify_change_status status)
 {
 	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	struct ufs_pa_layer_attr *dev_req_params = &host->dev_req_params;
 	int err = 0;
 
 	/* check the host controller state before sending hibern8 cmd */
@@ -1501,11 +1530,6 @@ static int ufs_qcom_clk_scale_notify(struct ufs_hba *hba,
 			return err;
 		}
 
-		ufs_qcom_cfg_timers(hba,
-				    dev_req_params->gear_rx,
-				    dev_req_params->pwr_rx,
-				    dev_req_params->hs_rate,
-				    false);
 		ufs_qcom_icc_update_bw(host);
 		ufshcd_uic_hibern8_exit(hba);
 	}