[PATCH v4] IBM power meter driver

["Darrick J. Wong" <djwong@us.ibm.com>]

Here's a fourth revision where I've tried to clean up the things that
people complained about, as well as shifted the sysfs file names to
match the spec that we've been drifting towards.
---
ibm_pex: Driver to export IBM PowerExecutive power meter sensors.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---

 drivers/hwmon/Kconfig  |   13 +
 drivers/hwmon/Makefile |    1 
 drivers/hwmon/ibmpex.c |  608 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 622 insertions(+), 0 deletions(-)

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 5ca5d95..591b666 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -315,6 +315,19 @@ config SENSORS_CORETEMP
 	  sensor inside your CPU. Supported all are all known variants
 	  of Intel Core family.
 
+config SENSORS_IBMPEX
+	tristate "IBM PowerExecutive temperature/power sensors"
+	select IPMI_SI
+	depends on IPMI_HANDLER
+	help
+	  If you say yes here you get support for the temperature and
+	  power sensors in various IBM System X servers that support
+	  PowerExecutive.  So far this includes the x3550, x3650, x3655,
+	  x3755, and certain HS20 blades.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called ibmpex.
+
 config SENSORS_IT87
 	tristate "ITE IT87xx and compatibles"
 	select HWMON_VID
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 5070cf7..0fcbcb4 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -38,6 +38,7 @@ obj-$(CONFIG_SENSORS_GL518SM)	+= gl518sm.o
 obj-$(CONFIG_SENSORS_GL520SM)	+= gl520sm.o
 obj-$(CONFIG_SENSORS_HDAPS)	+= hdaps.o
 obj-$(CONFIG_SENSORS_I5K_AMB)	+= i5k_amb.o
+obj-$(CONFIG_SENSORS_IBMPEX)	+= ibmpex.o
 obj-$(CONFIG_SENSORS_IPMI)	+= ipmisensors.o
 obj-$(CONFIG_SENSORS_IT87)	+= it87.o
 obj-$(CONFIG_SENSORS_K8TEMP)	+= k8temp.o
diff --git a/drivers/hwmon/ibmpex.c b/drivers/hwmon/ibmpex.c
new file mode 100644
index 0000000..fe2c261
--- /dev/null
+++ b/drivers/hwmon/ibmpex.c
@@ -0,0 +1,608 @@
+/*
+ * A hwmon driver for the IBM PowerExecutive temperature/power sensors
+ * Copyright (C) 2007 IBM
+ *
+ * Author: Darrick J. Wong <djwong@us.ibm.com>
+ *
+ * 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/ipmi.h>
+#include <linux/module.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/mutex.h>
+
+#define REFRESH_INTERVAL	(2 * HZ)
+#define DRVNAME			"ibmpex"
+
+#define PEX_GET_VERSION		1
+#define PEX_GET_SENSOR_COUNT	2
+#define PEX_GET_SENSOR_NAME	3
+#define PEX_RESET_HIGH_LOW	4
+#define PEX_GET_SENSOR_DATA	6
+
+#define PEX_NET_FUNCTION	0x3A
+#define PEX_COMMAND		0x3C
+
+static inline u16 extract_value(const char *data, int offset)
+{
+	return be16_to_cpup((u16 *)&data[offset]);
+}
+
+#define TEMP_SENSOR		1
+#define POWER_SENSOR		2
+
+#define PEX_SENSOR_TYPE_LEN	3
+static u8 const power_sensor_sig[] = {0x70, 0x77, 0x72};
+static u8 const temp_sensor_sig[]  = {0x74, 0x65, 0x6D};
+
+#define PEX_MULT_LEN		2
+static u8 const watt_sensor_sig[]  = {0x41, 0x43};
+
+#define PEX_NUM_SENSOR_FUNCS	3
+static char const * const power_sensor_name_templates[] = {
+	"%s%d_average",
+	"%s%d_average_lowest",
+	"%s%d_average_highest"
+};
+static char const * const temp_sensor_name_templates[] = {
+	"%s%d_input",
+	"%s%d_input_lowest",
+	"%s%d_input_highest"
+};
+
+static void ibmpex_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
+static void ibmpex_register_bmc(int iface, struct device *dev);
+static void ibmpex_bmc_gone(int iface);
+
+struct ibmpex_sensor_data {
+	int			in_use;
+	s16			values[PEX_NUM_SENSOR_FUNCS];
+	int			multiplier;
+
+	struct sensor_device_attribute_2	attr[PEX_NUM_SENSOR_FUNCS];
+};
+
+struct ibmpex_bmc_data {
+	struct list_head	list;
+	struct device		*hwmon_dev;
+	struct device		*bmc_device;
+	struct mutex		lock;
+	char			valid;
+	unsigned long		last_updated;	/* In jiffies */
+
+	struct ipmi_addr	address;
+	struct completion	read_complete;
+	ipmi_user_t		user;
+	int			interface;
+
+	struct kernel_ipmi_msg	tx_message;
+	unsigned char		tx_msg_data[IPMI_MAX_MSG_LENGTH];
+	long			tx_msgid;
+
+	unsigned char		rx_msg_data[IPMI_MAX_MSG_LENGTH];
+	unsigned long		rx_msg_len;
+	unsigned char		rx_result;
+	int			rx_recv_type;
+
+	unsigned char		sensor_major;
+	unsigned char		sensor_minor;
+
+	unsigned char		num_sensors;
+	struct ibmpex_sensor_data	*sensors;
+};
+
+struct ibmpex_driver_data {
+	struct list_head	bmc_data;
+	struct ipmi_smi_watcher	bmc_events;
+	struct ipmi_user_hndl	ipmi_hndlrs;
+};
+
+static struct ibmpex_driver_data driver_data = {
+	.bmc_data = LIST_HEAD_INIT(driver_data.bmc_data),
+	.bmc_events = {
+		.owner = THIS_MODULE,
+		.new_smi = ibmpex_register_bmc,
+		.smi_gone = ibmpex_bmc_gone,
+	},
+	.ipmi_hndlrs = {
+		.ipmi_recv_hndl = ibmpex_msg_handler,
+	},
+};
+
+static int ibmpex_send_message(struct ibmpex_bmc_data *data)
+{
+	int err;
+
+	err = ipmi_validate_addr(&data->address, sizeof(data->address));
+	if (err)
+		goto out;
+
+	data->tx_msgid++;
+	err = ipmi_request_settime(data->user, &data->address, data->tx_msgid,
+				   &data->tx_message, data, 0, 0, 0);
+	if (err)
+		goto out1;
+
+	return 0;
+out1:
+	printk(KERN_ERR "%s: request_settime=%x\n", __FUNCTION__, err);
+	return err;
+out:
+	printk(KERN_ERR "%s: validate_addr=%x\n", __FUNCTION__, err);
+	return err;
+}
+
+static int ibmpex_ver_check(struct ibmpex_bmc_data *data)
+{
+	data->tx_msg_data[0] = PEX_GET_VERSION;
+	data->tx_message.data_len = 1;
+	ibmpex_send_message(data);
+
+	wait_for_completion(&data->read_complete);
+
+	if (data->rx_result || data->rx_msg_len != 6)
+		return -ENOENT;
+
+	data->sensor_major = data->rx_msg_data[0];
+	data->sensor_minor = data->rx_msg_data[1];
+
+	printk(KERN_INFO DRVNAME ": Found BMC with sensor interface "
+	       "v%d.%d %d-%02d-%02d on interface %d\n",
+	       data->sensor_major,
+	       data->sensor_minor,
+	       extract_value(data->rx_msg_data, 2),
+	       data->rx_msg_data[4],
+	       data->rx_msg_data[5],
+	       data->interface);
+
+	return 0;
+}
+
+static int ibmpex_query_sensor_count(struct ibmpex_bmc_data *data)
+{
+	data->tx_msg_data[0] = PEX_GET_SENSOR_COUNT;
+	data->tx_message.data_len = 1;
+	ibmpex_send_message(data);
+
+	wait_for_completion(&data->read_complete);
+
+	if (data->rx_result || data->rx_msg_len != 1)
+		return -ENOENT;
+
+	return data->rx_msg_data[0];
+}
+
+static int ibmpex_query_sensor_name(struct ibmpex_bmc_data *data, int sensor)
+{
+	data->tx_msg_data[0] = PEX_GET_SENSOR_NAME;
+	data->tx_msg_data[1] = sensor;
+	data->tx_message.data_len = 2;
+	ibmpex_send_message(data);
+
+	wait_for_completion(&data->read_complete);
+
+	if (data->rx_result || data->rx_msg_len < 1)
+		return -ENOENT;
+
+	return 0;
+}
+
+static int ibmpex_query_sensor_data(struct ibmpex_bmc_data *data, int sensor)
+{
+	data->tx_msg_data[0] = PEX_GET_SENSOR_DATA;
+	data->tx_msg_data[1] = sensor;
+	data->tx_message.data_len = 2;
+	ibmpex_send_message(data);
+
+	wait_for_completion(&data->read_complete);
+
+	if (data->rx_result || data->rx_msg_len < 26) {
+		printk(KERN_ERR "Error reading sensor %d, please check.\n",
+		       sensor);
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
+static int ibmpex_reset_high_low_data(struct ibmpex_bmc_data *data)
+{
+	data->tx_msg_data[0] = PEX_RESET_HIGH_LOW;
+	data->tx_message.data_len = 1;
+	ibmpex_send_message(data);
+
+	wait_for_completion(&data->read_complete);
+
+	return 0;
+}
+
+static void ibmpex_update_device(struct ibmpex_bmc_data *data)
+{
+	int i, err;
+
+	mutex_lock(&data->lock);
+	if (time_before(jiffies, data->last_updated + REFRESH_INTERVAL) &&
+	    data->valid)
+		goto out;
+
+	for (i = 0; i < data->num_sensors; i++) {
+		if (!data->sensors[i].in_use)
+			continue;
+		err = ibmpex_query_sensor_data(data, i);
+		if (err)
+			continue;
+		data->sensors[i].values[0] =
+			extract_value(data->rx_msg_data, 16);
+		data->sensors[i].values[1] =
+			extract_value(data->rx_msg_data, 18);
+		data->sensors[i].values[2] =
+			extract_value(data->rx_msg_data, 20);
+	}
+
+	data->last_updated = jiffies;
+	data->valid = 1;
+
+out:
+	mutex_unlock(&data->lock);
+}
+
+static struct ibmpex_bmc_data *get_bmc_data(int iface)
+{
+	struct ibmpex_bmc_data *p, *next;
+
+	list_for_each_entry_safe(p, next, &driver_data.bmc_data, list)
+		if (p->interface == iface)
+			return p;
+
+	return NULL;
+}
+
+static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
+			 char *buf)
+{
+	return sprintf(buf, "%s\n", DRVNAME);
+}
+static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
+
+static ssize_t ibmpex_show_sensor(struct device *dev,
+				  struct device_attribute *devattr,
+				  char *buf)
+{
+	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
+	struct ibmpex_bmc_data *data = dev_get_drvdata(dev);
+	int mult = data->sensors[attr->index].multiplier;
+	ibmpex_update_device(data);
+
+	return sprintf(buf, "%d\n",
+		       data->sensors[attr->index].values[attr->nr] * mult);
+}
+
+static ssize_t ibmpex_reset_high_low(struct device *dev,
+				     struct device_attribute *devattr,
+				     const char *buf,
+				     size_t count)
+{
+	struct ibmpex_bmc_data *data = dev_get_drvdata(dev);
+
+	ibmpex_reset_high_low_data(data);
+
+	return count;
+}
+
+static SENSOR_DEVICE_ATTR(reset_high_low, S_IWUSR, NULL,
+			  ibmpex_reset_high_low, 0);
+
+static int is_power_sensor(const char *sensor_id, int len)
+{
+	if (len < PEX_SENSOR_TYPE_LEN)
+		return 0;
+
+	if (!memcmp(sensor_id, power_sensor_sig, PEX_SENSOR_TYPE_LEN))
+		return 1;
+	return 0;
+}
+
+static int is_temp_sensor(const char *sensor_id, int len)
+{
+	if (len < PEX_SENSOR_TYPE_LEN)
+		return 0;
+
+	if (!memcmp(sensor_id, temp_sensor_sig, PEX_SENSOR_TYPE_LEN))
+		return 1;
+	return 0;
+}
+
+static int power_sensor_multiplier(const char *sensor_id, int len)
+{
+	int i;
+
+	for (i = PEX_SENSOR_TYPE_LEN; i < len - 1; i++)
+		if (!memcmp(&sensor_id[i], watt_sensor_sig, PEX_MULT_LEN))
+			return 1000000;
+
+	return 100000;
+}
+
+static int create_sensor(struct ibmpex_bmc_data *data, int type,
+			 int counter, int sensor, int func)
+{
+	int err;
+	char *n;
+
+	n = kmalloc(32, GFP_KERNEL);
+	if (!n)
+		return -ENOMEM;
+
+	if (type == TEMP_SENSOR)
+		sprintf(n, temp_sensor_name_templates[func], "temp", counter);
+	else if (type == POWER_SENSOR)
+		sprintf(n, power_sensor_name_templates[func], "power", counter);
+
+	data->sensors[sensor].attr[func].dev_attr.attr.name = n;
+	data->sensors[sensor].attr[func].dev_attr.attr.mode = S_IRUGO;
+	data->sensors[sensor].attr[func].dev_attr.show = ibmpex_show_sensor;
+	data->sensors[sensor].attr[func].index = sensor;
+	data->sensors[sensor].attr[func].nr = func;
+
+	err = device_create_file(data->bmc_device,
+				 &data->sensors[sensor].attr[func].dev_attr);
+	if (err) {
+		data->sensors[sensor].attr[func].dev_attr.attr.name = NULL;
+		kfree(n);
+		return err;
+	}
+
+	return 0;
+}
+
+static int ibmpex_find_sensors(struct ibmpex_bmc_data *data)
+{
+	int i, j, err;
+	int sensor_type;
+	int sensor_counter;
+	int num_power = 0;
+	int num_temp = 0;
+
+	err = ibmpex_query_sensor_count(data);
+	if (err <= 0)
+		return -ENOENT;
+	data->num_sensors = err;
+
+	data->sensors = kzalloc(data->num_sensors * sizeof(*data->sensors),
+				GFP_KERNEL);
+	if (!data->sensors)
+		return -ENOMEM;
+
+	for (i = 0; i < data->num_sensors; i++) {
+		err = ibmpex_query_sensor_name(data, i);
+		if (err)
+			continue;
+
+		if (is_power_sensor(data->rx_msg_data, data->rx_msg_len)) {
+			sensor_type = POWER_SENSOR;
+			num_power++;
+			sensor_counter = num_power;
+			data->sensors[i].multiplier =
+				power_sensor_multiplier(data->rx_msg_data,
+						     data->rx_msg_len);
+		} else if (is_temp_sensor(data->rx_msg_data,
+					  data->rx_msg_len)) {
+			sensor_type = TEMP_SENSOR;
+			num_temp++;
+			sensor_counter = num_temp;
+			data->sensors[i].multiplier = 1;
+		} else
+			continue;
+
+		data->sensors[i].in_use = 1;
+
+		/* Create attributes */
+		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
+			err = create_sensor(data, sensor_type, sensor_counter,
+					    i, j);
+			if (err)
+				goto exit_remove;
+		}
+	}
+
+	err = device_create_file(data->bmc_device,
+			&sensor_dev_attr_reset_high_low.dev_attr);
+	if (err)
+		goto exit_remove;
+
+	err = device_create_file(data->bmc_device,
+			&sensor_dev_attr_name.dev_attr);
+	if (err)
+		goto exit_remove;
+
+	return 0;
+
+exit_remove:
+	device_remove_file(data->bmc_device,
+			   &sensor_dev_attr_reset_high_low.dev_attr);
+	device_remove_file(data->bmc_device, &sensor_dev_attr_name.dev_attr);
+	for (i = 0; i < data->num_sensors; i++)
+		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
+			if (!data->sensors[i].attr[j].dev_attr.attr.name)
+				continue;
+			device_remove_file(data->bmc_device,
+				&data->sensors[i].attr[j].dev_attr);
+			kfree(data->sensors[i].attr[j].dev_attr.attr.name);
+		}
+
+	kfree(data->sensors);
+	return err;
+}
+
+static void ibmpex_register_bmc(int iface, struct device *dev)
+{
+	struct ibmpex_bmc_data *data;
+	int err;
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		printk(KERN_ERR DRVNAME ": Insufficient memory for BMC "
+		       "interface %d.\n", data->interface);
+		return;
+	}
+
+	data->address.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
+	data->address.channel = IPMI_BMC_CHANNEL;
+	data->address.data[0] = 0;
+	data->interface = iface;
+	data->bmc_device = dev;
+
+	/* Create IPMI messaging interface user */
+	err = ipmi_create_user(data->interface, &driver_data.ipmi_hndlrs,
+			       data, &data->user);
+	if (err < 0) {
+		printk(KERN_ERR DRVNAME ": Error, unable to register user with "
+		       "ipmi interface %d\n",
+		       data->interface);
+		goto out;
+	}
+
+	mutex_init(&data->lock);
+
+	/* Initialize message */
+	data->tx_msgid = 0;
+	init_completion(&data->read_complete);
+	data->tx_message.netfn = PEX_NET_FUNCTION;
+	data->tx_message.cmd = PEX_COMMAND;
+	data->tx_message.data = data->tx_msg_data;
+
+	/* Does this BMC support PowerExecutive? */
+	err = ibmpex_ver_check(data);
+	if (err)
+		goto out_user;
+
+	/* Register the BMC as a HWMON class device */
+	data->hwmon_dev = hwmon_device_register(data->bmc_device);
+
+	if (IS_ERR(data->hwmon_dev)) {
+		printk(KERN_ERR DRVNAME ": Error, unable to register hwmon "
+		       "class device for interface %d\n",
+		       data->interface);
+		kfree(data);
+		return;
+	}
+
+	/* finally add the new bmc data to the bmc data list */
+	dev_set_drvdata(dev, data);
+	list_add_tail(&data->list, &driver_data.bmc_data);
+
+	/* Now go find all the sensors */
+	err = ibmpex_find_sensors(data);
+	if (err) {
+		printk(KERN_ERR "Error %d allocating memory\n", err);
+		goto out_register;
+	}
+
+	return;
+
+out_register:
+	hwmon_device_unregister(data->hwmon_dev);
+out_user:
+	ipmi_destroy_user(data->user);
+out:
+	kfree(data);
+}
+
+static void ibmpex_bmc_delete(struct ibmpex_bmc_data *data)
+{
+	int i, j;
+
+	device_remove_file(data->bmc_device,
+			   &sensor_dev_attr_reset_high_low.dev_attr);
+	device_remove_file(data->bmc_device, &sensor_dev_attr_name.dev_attr);
+	for (i = 0; i < data->num_sensors; i++)
+		for (j = 0; j < PEX_NUM_SENSOR_FUNCS; j++) {
+			if (!data->sensors[i].attr[j].dev_attr.attr.name)
+				continue;
+			device_remove_file(data->bmc_device,
+				&data->sensors[i].attr[j].dev_attr);
+			kfree(data->sensors[i].attr[j].dev_attr.attr.name);
+		}
+
+	list_del(&data->list);
+	dev_set_drvdata(data->bmc_device, NULL);
+	hwmon_device_unregister(data->hwmon_dev);
+	ipmi_destroy_user(data->user);
+	kfree(data->sensors);
+	kfree(data);
+}
+
+static void ibmpex_bmc_gone(int iface)
+{
+	struct ibmpex_bmc_data *data = get_bmc_data(iface);
+
+	if (!data)
+		return;
+
+	ibmpex_bmc_delete(data);
+}
+
+static void ibmpex_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
+{
+	struct ibmpex_bmc_data *data = (struct ibmpex_bmc_data *)user_msg_data;
+
+	if (msg->msgid != data->tx_msgid) {
+		printk(KERN_ERR "Received msgid (%02x) and transmitted "
+		       "msgid (%02x) mismatch!\n",
+		       (int)msg->msgid,
+		       (int)data->tx_msgid);
+		ipmi_free_recv_msg(msg);
+		return;
+	}
+
+	data->rx_recv_type = msg->recv_type;
+	if (msg->msg.data_len > 0)
+		data->rx_result = msg->msg.data[0];
+	else
+		data->rx_result = IPMI_UNKNOWN_ERR_COMPLETION_CODE;
+
+	if (msg->msg.data_len > 1) {
+		data->rx_msg_len = msg->msg.data_len - 1;
+		memcpy(data->rx_msg_data, msg->msg.data + 1, data->rx_msg_len);
+	} else
+		data->rx_msg_len = 0;
+
+	ipmi_free_recv_msg(msg);
+	complete(&data->read_complete);
+}
+
+static int __init ibmpex_init(void)
+{
+	return ipmi_smi_watcher_register(&driver_data.bmc_events);
+}
+
+static void __exit ibmpex_exit(void)
+{
+	struct ibmpex_bmc_data *p, *next;
+
+	ipmi_smi_watcher_unregister(&driver_data.bmc_events);
+	list_for_each_entry_safe(p, next, &driver_data.bmc_data, list)
+		ibmpex_bmc_delete(p);
+}
+
+MODULE_AUTHOR("Darrick J. Wong <djwong@us.ibm.com>");
+MODULE_DESCRIPTION("IBM PowerExecutive power/temperature sensor driver");
+MODULE_LICENSE("GPL");
+
+module_init(ibmpex_init);
+module_exit(ibmpex_exit);

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