powerpc/powernv: hwmon driver for power values, fan rpm and temperature

This patch adds basic kernel enablement for reading power values, fan
speed rpm and temperature values on powernv platforms which will
be exported to user space through sysfs interface.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.vnet.ibm.com>
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

3 files changed, 538 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5ce43d8dfa98..ad4cdcbc618b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -557,6 +557,14 @@ config SENSORS_IBMPEX
 	  This driver can also be built as a module.  If so, the module
 	  will be called ibmpex.
 
+config SENSORS_IBMPOWERNV
+	tristate "IBM PowerNv Platform temperature/power/fan sensor"
+	depends on PPC_POWERNV
+	default y
+	help
+	  If you say yes here you get support for the temperature/fan/power
+	  sensors on your platform.
+
 config SENSORS_IIO_HWMON
 	tristate "Hwmon driver that uses channels specified via iio maps"
 	depends on IIO
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index ec7cde06eb52..807e1721ed79 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_SENSORS_ULTRA45)	+= ultra45_env.o
 obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
 obj-$(CONFIG_SENSORS_IBMAEM)	+= ibmaem.o
 obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
+obj-$(CONFIG_SENSORS_IBMPOWERNV)+= ibmpowernv.o
 obj-$(CONFIG_SENSORS_IIO_HWMON) += iio_hwmon.o
 obj-$(CONFIG_SENSORS_INA209)	+= ina209.o
 obj-$(CONFIG_SENSORS_INA2XX)	+= ina2xx.o
diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
new file mode 100644
index 000000000000..b7b1297a9b02
--- /dev/null
+++ b/drivers/hwmon/ibmpowernv.c
@@ -0,0 +1,529 @@
+/*
+ * hwmon driver for temperature/power/fan on IBM PowerNV platform
+ * Copyright (C) 2013 IBM
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+
+#include <linux/jiffies.h>
+#include <linux/platform_device.h>
+#include <asm/opal.h>
+#include <linux/err.h>
+
+MODULE_DESCRIPTION("IBM PowerNV Platform power/temp/fan sensor hwmon module");
+MODULE_LICENSE("GPL");
+
+#define MAX_ATTR_LENGTH		32
+
+/* Device tree sensor name prefixes. The device tree has the names in the
+ * format "cooling-fan#2-faulted" where the "cooling-fan" is the sensor type,
+ * 2 is the sensor count, and "faulted" is the sensor data attribute type.
+ */
+#define DT_FAULT_ATTR_SUFFIX		"faulted"
+#define DT_DATA_ATTR_SUFFIX		"data"
+#define DT_THRESHOLD_ATTR_SUFFIX	"thrs"
+
+enum sensors {
+	FAN,
+	TEMPERATURE,
+	POWERSUPPLY,
+	POWER,
+	MAX_SENSOR_TYPE,
+};
+
+enum attributes {
+	INPUT,
+	MINIMUM,
+	MAXIMUM,
+	FAULT,
+	MAX_ATTR_TYPES
+};
+
+static struct sensor_name {
+	char *name;
+	char *compaible;
+} sensor_names[] = {
+		{"fan-sensor", "ibm,opal-sensor-cooling-fan"},
+		{"amb-temp-sensor", "ibm,opal-sensor-amb-temp"},
+		{"power-sensor", "ibm,opal-sensor-power-supply"},
+		{"power", "ibm,opal-sensor-power"}
+};
+
+static const char * const attribute_type_table[] = {
+	"input",
+	"min",
+	"max",
+	"fault",
+	NULL
+};
+
+struct pdev_entry {
+	struct list_head list;
+	struct platform_device *pdev;
+	enum sensors type;
+};
+
+static LIST_HEAD(pdev_list);
+
+/* The sensors are categorised on type.
+ *
+ * The sensors of same type are categorised under a common platform device.
+ * So, The pdev is shared by all sensors of same type.
+ * Ex : temp1_input, temp1_max, temp2_input,temp2_max all share same platform
+ * device.
+ *
+ * "sensor_data" is the Platform device specific data.
+ * There is one hwmon_device instance for all the sensors of same type.
+ * This also holds the list of all sensors with same type but different
+ * attribute and index.
+ */
+struct sensor_specific_data {
+	u32 sensor_id; /* The hex value as in the device tree */
+	u32 sensor_index; /* The sensor instance index */
+	struct sensor_device_attribute sd_attr;
+	enum attributes attr_type;
+	char attr_name[64];
+};
+
+struct sensor_data {
+	struct device *hwmon_dev;
+	struct list_head sensor_list;
+	struct device_attribute name_attr;
+};
+
+struct  sensor_entry {
+	struct list_head list;
+	struct sensor_specific_data *sensor_data;
+};
+
+static struct platform_device *powernv_sensor_get_pdev(enum sensors type)
+{
+	struct pdev_entry *p;
+	list_for_each_entry(p, &pdev_list, list)
+		if (p->type == type)
+			return p->pdev;
+
+	return NULL;
+}
+
+static struct sensor_specific_data *powernv_sensor_get_sensor_data(
+					struct sensor_data *pdata,
+					int index, enum attributes attr_type)
+{
+	struct sensor_entry *p;
+	list_for_each_entry(p, &pdata->sensor_list, list)
+		if ((p->sensor_data->sensor_index == index) &&
+		    (attr_type == p->sensor_data->attr_type))
+			return p->sensor_data;
+
+	return NULL;
+}
+
+static ssize_t show_name(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	return sprintf(buf, "%s\n", pdev->name);
+}
+
+/* Note: Data from the sensors for each sensor type needs to be converted to
+ * the dimension appropriate.
+ */
+static ssize_t show_sensor(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct sensor_device_attribute *sd_attr = to_sensor_dev_attr(devattr);
+	struct platform_device *pdev = to_platform_device(dev);
+	struct sensor_data *pdata = platform_get_drvdata(pdev);
+	struct sensor_specific_data *tdata = NULL;
+	enum sensors sensor_type = pdev->id;
+	u32 x = -1;
+	int ret;
+
+	if (sd_attr && sd_attr->dev_attr.attr.name) {
+		char *pos = strchr(sd_attr->dev_attr.attr.name, '_');
+		int i;
+
+		for (i = 0; i < MAX_ATTR_TYPES; i++) {
+			if (strcmp(pos+1, attribute_type_table[i]) == 0) {
+				tdata = powernv_sensor_get_sensor_data(pdata,
+						sd_attr->index, i);
+				break;
+			}
+		}
+	}
+
+	if (tdata) {
+		ret = opal_get_sensor_data(tdata->sensor_id, &x);
+		if (ret)
+			x = -1;
+	}
+
+	if (sensor_type == TEMPERATURE && x > 0) {
+		/* Temperature comes in Degrees and convert it to
+		 * milli-degrees.
+		 */
+		x = x*1000;
+	} else if (sensor_type == POWER && x > 0) {
+		/* Power value comes in watts, convert to micro-watts */
+		x = x * 1000000;
+	}
+
+	return sprintf(buf, "%d\n", x);
+}
+
+static u32 get_sensor_index_from_name(const char *name)
+{
+	char *hash_position = strchr(name, '#');
+	u32 index = 0, copy_length;
+	char newbuf[8];
+
+	if (hash_position) {
+		copy_length = strchr(hash_position, '-') - hash_position - 1;
+		if (copy_length < sizeof(newbuf)) {
+			strncpy(newbuf, hash_position + 1, copy_length);
+			sscanf(newbuf, "%d", &index);
+		}
+	}
+
+	return index;
+}
+
+static inline void get_sensor_suffix_from_name(const char *name, char *suffix)
+{
+	char *dash_position = strrchr(name, '-');
+	if (dash_position)
+		strncpy(suffix, dash_position+1, MAX_ATTR_LENGTH);
+	else
+		strcpy(suffix,"");
+}
+
+static int get_sensor_attr_properties(const char *sensor_name,
+		enum sensors sensor_type, enum attributes *attr_type,
+		u32 *sensor_index)
+{
+	char suffix[MAX_ATTR_LENGTH];
+
+	*attr_type = MAX_ATTR_TYPES;
+	*sensor_index = get_sensor_index_from_name(sensor_name);
+	if (*sensor_index == 0)
+		return -EINVAL;
+
+	get_sensor_suffix_from_name(sensor_name, suffix);
+	if (strcmp(suffix, "") == 0)
+		return -EINVAL;
+
+	if (strcmp(suffix, DT_FAULT_ATTR_SUFFIX) == 0)
+		*attr_type = FAULT;
+	else if (strcmp(suffix, DT_DATA_ATTR_SUFFIX) == 0)
+		*attr_type = INPUT;
+	else if ((sensor_type == TEMPERATURE) &&
+			(strcmp(suffix, DT_THRESHOLD_ATTR_SUFFIX) == 0))
+		*attr_type = MAXIMUM;
+	else if ((sensor_type == FAN) &&
+			(strcmp(suffix, DT_THRESHOLD_ATTR_SUFFIX) == 0))
+		*attr_type = MINIMUM;
+	else
+		return -ENOENT;
+
+	if (((sensor_type == FAN) && ((*attr_type == INPUT) ||
+				    (*attr_type == MINIMUM)))
+	    || ((sensor_type == TEMPERATURE) && ((*attr_type == INPUT) ||
+						 (*attr_type == MAXIMUM)))
+	    || ((sensor_type == POWER) && ((*attr_type == INPUT))))
+		return 0;
+
+	return -ENOENT;
+}
+
+static int create_sensor_attr(struct sensor_specific_data *tdata,
+		struct device *dev, enum sensors sensor_type,
+		enum attributes attr_type)
+{
+	int err = 0;
+	char temp_file_prefix[50];
+	static const char *const file_name_format = "%s%d_%s";
+
+	tdata->attr_type = attr_type;
+
+	if (sensor_type == FAN)
+		strcpy(temp_file_prefix, "fan");
+	else if (sensor_type == TEMPERATURE)
+		strcpy(temp_file_prefix, "temp");
+	else if (sensor_type == POWERSUPPLY)
+		strcpy(temp_file_prefix, "powersupply");
+	else if (sensor_type == POWER)
+		strcpy(temp_file_prefix, "power");
+
+	snprintf(tdata->attr_name, sizeof(tdata->attr_name), file_name_format,
+		 temp_file_prefix, tdata->sensor_index,
+		 attribute_type_table[tdata->attr_type]);
+
+	sysfs_attr_init(&tdata->sd_attr.dev_attr.attr);
+	tdata->sd_attr.dev_attr.attr.name = tdata->attr_name;
+	tdata->sd_attr.dev_attr.attr.mode = S_IRUGO;
+	tdata->sd_attr.dev_attr.show = show_sensor;
+
+	tdata->sd_attr.index = tdata->sensor_index;
+	err = device_create_file(dev, &tdata->sd_attr.dev_attr);
+
+	return err;
+}
+
+static int create_name_attr(struct sensor_data *pdata,
+				struct device *dev)
+{
+	sysfs_attr_init(&pdata->name_attr.attr);
+	pdata->name_attr.attr.name = "name";
+	pdata->name_attr.attr.mode = S_IRUGO;
+	pdata->name_attr.show = show_name;
+	return device_create_file(dev, &pdata->name_attr);
+}
+
+static int create_platform_device(enum sensors sensor_type,
+					struct platform_device **pdev)
+{
+	struct pdev_entry *pdev_entry = NULL;
+	int err;
+
+	*pdev = platform_device_alloc(sensor_names[sensor_type].name,
+			sensor_type);
+	if (!*pdev) {
+		pr_err("Device allocation failed\n");
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	pdev_entry = kzalloc(sizeof(struct pdev_entry), GFP_KERNEL);
+	if (!pdev_entry) {
+		pr_err("Device allocation failed\n");
+		err = -ENOMEM;
+		goto exit_device_put;
+	}
+
+	err = platform_device_add(*pdev);
+	if (err) {
+		pr_err("Device addition failed (%d)\n", err);
+		goto exit_device_free;
+	}
+
+	pdev_entry->pdev = *pdev;
+	pdev_entry->type = (*pdev)->id;
+
+	list_add_tail(&pdev_entry->list, &pdev_list);
+
+	return 0;
+exit_device_free:
+	kfree(pdev_entry);
+exit_device_put:
+	platform_device_put(*pdev);
+exit:
+	return err;
+}
+
+static int create_sensor_data(struct platform_device *pdev)
+{
+	struct sensor_data *pdata = NULL;
+	int err = 0;
+
+	pdata = kzalloc(sizeof(struct sensor_data), GFP_KERNEL);
+	if (!pdata) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	err = create_name_attr(pdata, &pdev->dev);
+	if (err)
+		goto exit_free;
+
+	pdata->hwmon_dev = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(pdata->hwmon_dev)) {
+		err = PTR_ERR(pdata->hwmon_dev);
+		dev_err(&pdev->dev, "Class registration failed (%d)\n",
+			err);
+		goto exit_name;
+	}
+
+	INIT_LIST_HEAD(&pdata->sensor_list);
+	platform_set_drvdata(pdev, pdata);
+
+	return 0;
+
+exit_name:
+	device_remove_file(&pdev->dev, &pdata->name_attr);
+exit_free:
+	kfree(pdata);
+exit:
+	return err;
+}
+
+static void delete_sensor_attr(struct sensor_data *pdata)
+{
+	struct sensor_entry *s, *l;
+
+	list_for_each_entry_safe(s, l, &pdata->sensor_list, list) {
+		struct sensor_specific_data *tdata = s->sensor_data;
+			kfree(tdata);
+			list_del(&s->list);
+			kfree(s);
+		}
+}
+
+static int powernv_sensor_init(u32 sensor_id, const struct device_node *np,
+		enum sensors sensor_type, enum attributes attr_type,
+		u32 sensor_index)
+{
+	struct platform_device *pdev = powernv_sensor_get_pdev(sensor_type);
+	struct sensor_specific_data *tdata;
+	struct sensor_entry *sensor_entry;
+	struct sensor_data *pdata;
+	int err = 0;
+
+	if (!pdev) {
+		err = create_platform_device(sensor_type, &pdev);
+		if (err)
+			goto exit;
+
+		err = create_sensor_data(pdev);
+		if (err)
+			goto exit;
+	}
+
+	pdata = platform_get_drvdata(pdev);
+	if (!pdata) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	tdata = kzalloc(sizeof(struct sensor_specific_data), GFP_KERNEL);
+	if (!tdata) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	tdata->sensor_id = sensor_id;
+	tdata->sensor_index = sensor_index;
+
+	err = create_sensor_attr(tdata, &pdev->dev, sensor_type, attr_type);
+	if (err)
+		goto exit_free;
+
+	sensor_entry = kzalloc(sizeof(struct sensor_entry), GFP_KERNEL);
+	if (!sensor_entry) {
+		err = -ENOMEM;
+		goto exit_attr;
+	}
+
+	sensor_entry->sensor_data = tdata;
+
+	list_add_tail(&sensor_entry->list, &pdata->sensor_list);
+
+	return 0;
+exit_attr:
+	device_remove_file(&pdev->dev, &tdata->sd_attr.dev_attr);
+exit_free:
+	kfree(tdata);
+exit:
+	return err;
+}
+
+static void delete_unregister_sensors(void)
+{
+	struct pdev_entry *p, *n;
+
+	list_for_each_entry_safe(p, n, &pdev_list, list) {
+		struct sensor_data *pdata = platform_get_drvdata(p->pdev);
+			if (pdata) {
+				delete_sensor_attr(pdata);
+
+				hwmon_device_unregister(pdata->hwmon_dev);
+				kfree(pdata);
+			}
+		platform_device_unregister(p->pdev);
+		list_del(&p->list);
+		kfree(p);
+	}
+}
+
+static int __init powernv_hwmon_init(void)
+{
+	struct device_node *opal, *np = NULL;
+	enum attributes attr_type;
+	enum sensors type;
+	const u32 *sensor_id;
+	u32 sensor_index;
+	int err;
+
+	opal = of_find_node_by_path("/ibm,opal/sensors");
+	if (!opal) {
+		pr_err("%s: Opal 'sensors' node not found\n", __func__);
+		return -ENXIO;
+	}
+
+	for_each_child_of_node(opal, np) {
+		if (np->name == NULL)
+			continue;
+
+		for (type = 0; type < MAX_SENSOR_TYPE; type++)
+			if (of_device_is_compatible(np,
+					sensor_names[type].compaible))
+				break;
+
+		if (type == MAX_SENSOR_TYPE)
+			continue;
+
+		if (get_sensor_attr_properties(np->name, type, &attr_type,
+				&sensor_index))
+			continue;
+
+		sensor_id = of_get_property(np, "sensor-id", NULL);
+		if (!sensor_id) {
+			pr_info("%s: %s doesn't have sensor-id\n", __func__,
+					np->name);
+			continue;
+		}
+
+		err = powernv_sensor_init(*sensor_id, np, type, attr_type,
+				sensor_index);
+		if (err) {
+			of_node_put(opal);
+			goto exit;
+		}
+	}
+	of_node_put(opal);
+
+	return 0;
+exit:
+	delete_unregister_sensors();
+	return err;
+
+}
+
+static void powernv_hwmon_exit(void)
+{
+	delete_unregister_sensors();
+}
+
+module_init(powernv_hwmon_init);
+module_exit(powernv_hwmon_exit);