[PATCH v3 2/2] scsi: ufs: Add temperature notification exception handling

[Avri Altman <avri.altman@wdc.com>]

The device may notify the host of an extreme temperature by using the
exception event mechanism. The exception can be raised when the device’s
Tcase temperature is either too high or too low.

It is essentially up to the platform to decide what further actions need
to be taken. leave a placeholder for a designated vop for that.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufs-hwmon.c | 14 ++++++++++++++
 drivers/scsi/ufs/ufs.h       |  2 ++
 drivers/scsi/ufs/ufshcd.c    | 21 +++++++++++++++++++++
 drivers/scsi/ufs/ufshcd.h    |  2 ++
 4 files changed, 39 insertions(+)

diff --git a/drivers/scsi/ufs/ufs-hwmon.c b/drivers/scsi/ufs/ufs-hwmon.c
index a50e83f645f4..b466b4649c21 100644
--- a/drivers/scsi/ufs/ufs-hwmon.c
+++ b/drivers/scsi/ufs/ufs-hwmon.c
@@ -177,3 +177,17 @@ void ufs_hwmon_remove(struct ufs_hba *hba)
 	hba->hwmon_device = NULL;
 	kfree(data);
 }
+
+void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask)
+{
+	if (!hba->hwmon_device)
+		return;
+
+	if (ee_mask & MASK_EE_TOO_HIGH_TEMP)
+		hwmon_notify_event(hba->hwmon_device, hwmon_temp,
+				   hwmon_temp_max_alarm, 0);
+
+	if (ee_mask & MASK_EE_TOO_LOW_TEMP)
+		hwmon_notify_event(hba->hwmon_device, hwmon_temp,
+				   hwmon_temp_min_alarm, 0);
+}
diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 171b27be7b1d..d9bc048c2a71 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -377,6 +377,8 @@ enum {
 	MASK_EE_PERFORMANCE_THROTTLING	= BIT(6),
 };
 
+#define MASK_EE_URGENT_TEMP (MASK_EE_TOO_HIGH_TEMP | MASK_EE_TOO_LOW_TEMP)
+
 /* Background operation status */
 enum bkops_status {
 	BKOPS_STATUS_NO_OP               = 0x0,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 90c2e9677435..3f4c7124b74b 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5642,6 +5642,24 @@ static void ufshcd_bkops_exception_event_handler(struct ufs_hba *hba)
 				__func__, err);
 }
 
+static void ufshcd_temp_exception_event_handler(struct ufs_hba *hba, u16 status)
+{
+	u32 value;
+
+	if (ufshcd_query_attr_retry(hba, UPIU_QUERY_OPCODE_READ_ATTR,
+				QUERY_ATTR_IDN_CASE_ROUGH_TEMP, 0, 0, &value))
+		return;
+
+	dev_info(hba->dev, "exception Tcase %d\n", value - 80);
+
+	ufs_hwmon_notify_event(hba, status & MASK_EE_URGENT_TEMP);
+
+	/*
+	 * A placeholder for the platform vendors to add whatever additional
+	 * steps required
+	 */
+}
+
 static int __ufshcd_wb_toggle(struct ufs_hba *hba, bool set, enum flag_idn idn)
 {
 	u8 index;
@@ -5821,6 +5839,9 @@ static void ufshcd_exception_event_handler(struct work_struct *work)
 	if (status & hba->ee_drv_mask & MASK_EE_URGENT_BKOPS)
 		ufshcd_bkops_exception_event_handler(hba);
 
+	if (status & hba->ee_drv_mask & MASK_EE_URGENT_TEMP)
+		ufshcd_temp_exception_event_handler(hba, status);
+
 	ufs_debugfs_exception_event(hba, status);
 out:
 	ufshcd_scsi_unblock_requests(hba);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 798a408d71e5..e6abce9a8b00 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -1063,9 +1063,11 @@ static inline u8 ufshcd_wb_get_query_index(struct ufs_hba *hba)
 #ifdef CONFIG_SCSI_UFS_HWMON
 void ufs_hwmon_probe(struct ufs_hba *hba, u8 mask);
 void ufs_hwmon_remove(struct ufs_hba *hba);
+void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask);
 #else
 static inline void ufs_hwmon_probe(struct ufs_hba *hba, u8 mask) {}
 static inline void ufs_hwmon_remove(struct ufs_hba *hba) {}
+void ufs_hwmon_notify_event(struct ufs_hba *hba, u8 ee_mask) {}
 #endif
 
 #ifdef CONFIG_PM
-- 
2.17.1