[PATCH v2] hwmon: (pmbus/ibm-cffps) Add clear_faults debugfs entry

[Brandon Wyman <bjwyman@gmail.com>]

Add a clear_faults write-only debugfs entry for the ibm-cffps device
driver.

Certain IBM power supplies require clearing some latched faults in order
to indicate that the fault has indeed been observed/noticed.

Signed-off-by: Brandon Wyman <bjwyman@gmail.com>
---
V1 -> V2: Explain why this change is needed

 drivers/hwmon/pmbus/ibm-cffps.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/hwmon/pmbus/ibm-cffps.c b/drivers/hwmon/pmbus/ibm-cffps.c
index e3294a1a54bb..3f02dde02a4b 100644
--- a/drivers/hwmon/pmbus/ibm-cffps.c
+++ b/drivers/hwmon/pmbus/ibm-cffps.c
@@ -67,6 +67,7 @@ enum {
 	CFFPS_DEBUGFS_CCIN,
 	CFFPS_DEBUGFS_FW,
 	CFFPS_DEBUGFS_ON_OFF_CONFIG,
+	CFFPS_DEBUGFS_CLEAR_FAULTS,
 	CFFPS_DEBUGFS_NUM_ENTRIES
 };
 
@@ -274,6 +275,13 @@ static ssize_t ibm_cffps_debugfs_write(struct file *file,
 		if (rc)
 			return rc;
 
+		rc = 1;
+		break;
+	case CFFPS_DEBUGFS_CLEAR_FAULTS:
+		rc = i2c_smbus_write_byte(psu->client, PMBUS_CLEAR_FAULTS);
+		if (rc < 0)
+			return rc;
+
 		rc = 1;
 		break;
 	default:
@@ -607,6 +615,9 @@ static int ibm_cffps_probe(struct i2c_client *client)
 	debugfs_create_file("on_off_config", 0644, ibm_cffps_dir,
 			    &psu->debugfs_entries[CFFPS_DEBUGFS_ON_OFF_CONFIG],
 			    &ibm_cffps_fops);
+	debugfs_create_file("clear_faults", 0200, ibm_cffps_dir,
+			    &psu->debugfs_entries[CFFPS_DEBUGFS_CLEAR_FAULTS],
+			    &ibm_cffps_fops);
 
 	return 0;
 }
-- 
2.25.1