scsi: ufs: provide sysfs attribute to select the PM level

This patch provides the sysfs attribute to choose the power management
level for UFS runtime and system suspend.
Reviewed-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/ufs/ufshcd.c

@@ -686,6 +686,28 @@ static inline int ufshcd_is_hba_active(struct ufs_hba *hba)
 	return (ufshcd_readl(hba, REG_CONTROLLER_ENABLE) & 0x1) ? 0 : 1;
 }
 
+static const char *ufschd_uic_link_state_to_string(
+			enum uic_link_state state)
+{
+	switch (state) {
+	case UIC_LINK_OFF_STATE:	return "OFF";
+	case UIC_LINK_ACTIVE_STATE:	return "ACTIVE";
+	case UIC_LINK_HIBERN8_STATE:	return "HIBERN8";
+	default:			return "UNKNOWN";
+	}
+}
+
+static const char *ufschd_ufs_dev_pwr_mode_to_string(
+			enum ufs_dev_pwr_mode state)
+{
+	switch (state) {
+	case UFS_ACTIVE_PWR_MODE:	return "ACTIVE";
+	case UFS_SLEEP_PWR_MODE:	return "SLEEP";
+	case UFS_POWERDOWN_PWR_MODE:	return "POWERDOWN";
+	default:			return "UNKNOWN";
+	}
+}
+
 u32 ufshcd_get_local_unipro_ver(struct ufs_hba *hba)
 {
 	/* HCI version 1.0 and 1.1 supports UniPro 1.41 */
@@ -6709,6 +6731,127 @@ int ufshcd_runtime_idle(struct ufs_hba *hba)
 }
 EXPORT_SYMBOL(ufshcd_runtime_idle);
 
+static inline ssize_t ufshcd_pm_lvl_store(struct device *dev,
+					   struct device_attribute *attr,
+					   const char *buf, size_t count,
+					   bool rpm)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	unsigned long flags, value;
+
+	if (kstrtoul(buf, 0, &value))
+		return -EINVAL;
+
+	if ((value < UFS_PM_LVL_0) || (value >= UFS_PM_LVL_MAX))
+		return -EINVAL;
+
+	spin_lock_irqsave(hba->host->host_lock, flags);
+	if (rpm)
+		hba->rpm_lvl = value;
+	else
+		hba->spm_lvl = value;
+	spin_unlock_irqrestore(hba->host->host_lock, flags);
+	return count;
+}
+
+static ssize_t ufshcd_rpm_lvl_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int curr_len;
+	u8 lvl;
+
+	curr_len = snprintf(buf, PAGE_SIZE,
+			    "\nCurrent Runtime PM level [%d] => dev_state [%s] link_state [%s]\n",
+			    hba->rpm_lvl,
+			    ufschd_ufs_dev_pwr_mode_to_string(
+				ufs_pm_lvl_states[hba->rpm_lvl].dev_state),
+			    ufschd_uic_link_state_to_string(
+				ufs_pm_lvl_states[hba->rpm_lvl].link_state));
+
+	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+			     "\nAll available Runtime PM levels info:\n");
+	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
+		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+				     "\tRuntime PM level [%d] => dev_state [%s] link_state [%s]\n",
+				    lvl,
+				    ufschd_ufs_dev_pwr_mode_to_string(
+					ufs_pm_lvl_states[lvl].dev_state),
+				    ufschd_uic_link_state_to_string(
+					ufs_pm_lvl_states[lvl].link_state));
+
+	return curr_len;
+}
+
+static ssize_t ufshcd_rpm_lvl_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	return ufshcd_pm_lvl_store(dev, attr, buf, count, true);
+}
+
+static void ufshcd_add_rpm_lvl_sysfs_nodes(struct ufs_hba *hba)
+{
+	hba->rpm_lvl_attr.show = ufshcd_rpm_lvl_show;
+	hba->rpm_lvl_attr.store = ufshcd_rpm_lvl_store;
+	sysfs_attr_init(&hba->rpm_lvl_attr.attr);
+	hba->rpm_lvl_attr.attr.name = "rpm_lvl";
+	hba->rpm_lvl_attr.attr.mode = 0644;
+	if (device_create_file(hba->dev, &hba->rpm_lvl_attr))
+		dev_err(hba->dev, "Failed to create sysfs for rpm_lvl\n");
+}
+
+static ssize_t ufshcd_spm_lvl_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ufs_hba *hba = dev_get_drvdata(dev);
+	int curr_len;
+	u8 lvl;
+
+	curr_len = snprintf(buf, PAGE_SIZE,
+			    "\nCurrent System PM level [%d] => dev_state [%s] link_state [%s]\n",
+			    hba->spm_lvl,
+			    ufschd_ufs_dev_pwr_mode_to_string(
+				ufs_pm_lvl_states[hba->spm_lvl].dev_state),
+			    ufschd_uic_link_state_to_string(
+				ufs_pm_lvl_states[hba->spm_lvl].link_state));
+
+	curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+			     "\nAll available System PM levels info:\n");
+	for (lvl = UFS_PM_LVL_0; lvl < UFS_PM_LVL_MAX; lvl++)
+		curr_len += snprintf((buf + curr_len), (PAGE_SIZE - curr_len),
+				     "\tSystem PM level [%d] => dev_state [%s] link_state [%s]\n",
+				    lvl,
+				    ufschd_ufs_dev_pwr_mode_to_string(
+					ufs_pm_lvl_states[lvl].dev_state),
+				    ufschd_uic_link_state_to_string(
+					ufs_pm_lvl_states[lvl].link_state));
+
+	return curr_len;
+}
+
+static ssize_t ufshcd_spm_lvl_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	return ufshcd_pm_lvl_store(dev, attr, buf, count, false);
+}
+
+static void ufshcd_add_spm_lvl_sysfs_nodes(struct ufs_hba *hba)
+{
+	hba->spm_lvl_attr.show = ufshcd_spm_lvl_show;
+	hba->spm_lvl_attr.store = ufshcd_spm_lvl_store;
+	sysfs_attr_init(&hba->spm_lvl_attr.attr);
+	hba->spm_lvl_attr.attr.name = "spm_lvl";
+	hba->spm_lvl_attr.attr.mode = 0644;
+	if (device_create_file(hba->dev, &hba->spm_lvl_attr))
+		dev_err(hba->dev, "Failed to create sysfs for spm_lvl\n");
+}
+
+static inline void ufshcd_add_sysfs_nodes(struct ufs_hba *hba)
+{
+	ufshcd_add_rpm_lvl_sysfs_nodes(hba);
+	ufshcd_add_spm_lvl_sysfs_nodes(hba);
+}
+
 /**
  * ufshcd_shutdown - shutdown routine
  * @hba: per adapter instance
@@ -7133,6 +7276,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
 	ufshcd_set_ufs_dev_active(hba);
 
 	async_schedule(ufshcd_async_scan, hba);
+	ufshcd_add_sysfs_nodes(hba);
 
 	return 0;
 

drivers/scsi/ufs/ufshcd.h

@@ -435,6 +435,8 @@ struct ufs_hba {
 	enum ufs_pm_level rpm_lvl;
 	/* Desired UFS power management level during system PM */
 	enum ufs_pm_level spm_lvl;
+	struct device_attribute rpm_lvl_attr;
+	struct device_attribute spm_lvl_attr;
 	int pm_op_in_progress;
 
 	struct ufshcd_lrb *lrb;