[PATCH V2] hwmon: (ibmpowernv) Add min/max attributes and current sensors

[Shilpasri G Bhat]

Add support for adding min/max values for the inband sensors copied by
OCC to main memory. And also add current(mA) sensors to the list.

Signed-off-by: Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx>
---
Changes from V1:
- Add functions to get min and max attribute strings
- Add function 'populate_sensor' to fill in the 'struct sensor_data'
  for each sensor.

 drivers/hwmon/ibmpowernv.c | 96 +++++++++++++++++++++++++++++++++++++---------
 1 file changed, 77 insertions(+), 19 deletions(-)

diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
index 6d2e660..d59262c 100644
--- a/drivers/hwmon/ibmpowernv.c
+++ b/drivers/hwmon/ibmpowernv.c
@@ -50,6 +50,7 @@ enum sensors {
 	TEMP,
 	POWER_SUPPLY,
 	POWER_INPUT,
+	CURRENT,
 	MAX_SENSOR_TYPE,
 };
 
@@ -65,7 +66,8 @@ enum sensors {
 	{"fan", "ibm,opal-sensor-cooling-fan"},
 	{"temp", "ibm,opal-sensor-amb-temp"},
 	{"in", "ibm,opal-sensor-power-supply"},
-	{"power", "ibm,opal-sensor-power"}
+	{"power", "ibm,opal-sensor-power"},
+	{"curr"}, /* Follows newer device tree compatible ibm,opal-sensor */
 };
 
 struct sensor_data {
@@ -287,6 +289,7 @@ static int populate_attr_groups(struct platform_device *pdev)
 	opal = of_find_node_by_path("/ibm,opal/sensors");
 	for_each_child_of_node(opal, np) {
 		const char *label;
+		int len;
 
 		if (np->name == NULL)
 			continue;
@@ -298,10 +301,14 @@ static int populate_attr_groups(struct platform_device *pdev)
 		sensor_groups[type].attr_count++;
 
 		/*
-		 * add a new attribute for labels
+		 * add attributes for labels, min and max
 		 */
 		if (!of_property_read_string(np, "label", &label))
 			sensor_groups[type].attr_count++;
+		if (of_find_property(np, "sensor-data-min", &len))
+			sensor_groups[type].attr_count++;
+		if (of_find_property(np, "sensor-data-max", &len))
+			sensor_groups[type].attr_count++;
 	}
 
 	of_node_put(opal);
@@ -337,6 +344,49 @@ static void create_hwmon_attr(struct sensor_data *sdata, const char *attr_name,
 	sdata->dev_attr.show = show;
 }
 
+static void populate_sensor(struct sensor_data *sdata, int od, int hd, int sid,
+			    const char *attr_name, enum sensors type,
+			    const struct attribute_group *pgroup,
+			    ssize_t (*show)(struct device *dev,
+					    struct device_attribute *attr,
+					    char *buf))
+{
+	sdata->id = sid;
+	sdata->type = type;
+	sdata->opal_index = od;
+	sdata->hwmon_index = hd;
+	create_hwmon_attr(sdata, attr_name, show);
+	pgroup->attrs[sensor_groups[type].attr_count++] = &sdata->dev_attr.attr;
+}
+
+static char *get_max_attr(enum sensors type)
+{
+	switch (type) {
+	case POWER_INPUT:
+		return "input_highest";
+	case TEMP:
+		return "max";
+	default:
+		break;
+	}
+
+	return "highest";
+}
+
+static char *get_min_attr(enum sensors type)
+{
+	switch (type) {
+	case POWER_INPUT:
+		return "input_lowest";
+	case TEMP:
+		return "min";
+	default:
+		break;
+	}
+
+	return "lowest";
+}
+
 /*
  * Iterate through the device tree for each child of 'sensors' node, create
  * a sysfs attribute file, the file is named by translating the DT node name
@@ -365,6 +415,7 @@ static int create_device_attrs(struct platform_device *pdev)
 	for_each_child_of_node(opal, np) {
 		const char *attr_name;
 		u32 opal_index;
+		u32 hwmon_index;
 		const char *label;
 
 		if (np->name == NULL)
@@ -386,9 +437,6 @@ static int create_device_attrs(struct platform_device *pdev)
 			continue;
 		}
 
-		sdata[count].id = sensor_id;
-		sdata[count].type = type;
-
 		/*
 		 * If we can not parse the node name, it means we are
 		 * running on a newer device tree. We can just forget
@@ -401,14 +449,12 @@ static int create_device_attrs(struct platform_device *pdev)
 			opal_index = INVALID_INDEX;
 		}
 
-		sdata[count].opal_index = opal_index;
-		sdata[count].hwmon_index =
-			get_sensor_hwmon_index(&sdata[count], sdata, count);
-
-		create_hwmon_attr(&sdata[count], attr_name, show_sensor);
-
-		pgroups[type]->attrs[sensor_groups[type].attr_count++] =
-				&sdata[count++].dev_attr.attr;
+		hwmon_index = get_sensor_hwmon_index(&sdata[count], sdata,
+						     count);
+		populate_sensor(&sdata[count], opal_index, hwmon_index,
+				sensor_id, attr_name, type, pgroups[type],
+				show_sensor);
+		count++;
 
 		if (!of_property_read_string(np, "label", &label)) {
 			/*
@@ -417,16 +463,28 @@ static int create_device_attrs(struct platform_device *pdev)
 			 * attribute. They are related to the same
 			 * sensor.
 			 */
-			sdata[count].type = type;
-			sdata[count].opal_index = sdata[count - 1].opal_index;
-			sdata[count].hwmon_index = sdata[count - 1].hwmon_index;
 
 			make_sensor_label(np, &sdata[count], label);
+			populate_sensor(&sdata[count], opal_index, hwmon_index,
+					sensor_id, "label", type, pgroups[type],
+					show_label);
+			count++;
+		}
 
-			create_hwmon_attr(&sdata[count], "label", show_label);
+		if (!of_property_read_u32(np, "sensor-data-max", &sensor_id)) {
+			attr_name = get_max_attr(type);
+			populate_sensor(&sdata[count], opal_index, hwmon_index,
+					sensor_id, attr_name, type,
+					pgroups[type], show_sensor);
+			count++;
+		}
 
-			pgroups[type]->attrs[sensor_groups[type].attr_count++] =
-				&sdata[count++].dev_attr.attr;
+		if (!of_property_read_u32(np, "sensor-data-min", &sensor_id)) {
+			attr_name = get_min_attr(type);
+			populate_sensor(&sdata[count], opal_index, hwmon_index,
+					sensor_id, attr_name, type,
+					pgroups[type], show_sensor);
+			count++;
 		}
 	}
 
-- 
1.8.3.1