/*

   * A hwmon driver for the IBM System Director Active Energy Manager (AEM)
   * temperature/power/energy sensors and capping functionality.

   * Copyright (C) 2008 IBM
   *

   * Author: Darrick J. Wong <darrick.wong@oracle.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
   */

  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #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>
  #include <linux/kdev_t.h>
  #include <linux/spinlock.h>
  #include <linux/idr.h>

  #include <linux/slab.h>

  #include <linux/sched.h>
  #include <linux/platform_device.h>
  #include <linux/math64.h>
  #include <linux/time.h>

  #include <linux/err.h>

  
  #define REFRESH_INTERVAL	(HZ)
  #define IPMI_TIMEOUT		(30 * HZ)
  #define DRVNAME			"aem"
  
  #define AEM_NETFN		0x2E
  
  #define AEM_FIND_FW_CMD		0x80
  #define AEM_ELEMENT_CMD		0x81
  #define AEM_FW_INSTANCE_CMD	0x82
  
  #define AEM_READ_ELEMENT_CFG	0x80
  #define AEM_READ_BUFFER		0x81
  #define AEM_READ_REGISTER	0x82
  #define AEM_WRITE_REGISTER	0x83
  #define AEM_SET_REG_MASK	0x84
  #define AEM_CLEAR_REG_MASK	0x85
  #define AEM_READ_ELEMENT_CFG2	0x86
  
  #define AEM_CONTROL_ELEMENT	0
  #define AEM_ENERGY_ELEMENT	1
  #define AEM_CLOCK_ELEMENT	4
  #define AEM_POWER_CAP_ELEMENT	7
  #define AEM_EXHAUST_ELEMENT	9
  #define AEM_POWER_ELEMENT	10
  
  #define AEM_MODULE_TYPE_ID	0x0001
  
  #define AEM2_NUM_ENERGY_REGS	2
  #define AEM2_NUM_PCAP_REGS	6
  #define AEM2_NUM_TEMP_REGS	2
  #define AEM2_NUM_SENSORS	14
  
  #define AEM1_NUM_ENERGY_REGS	1
  #define AEM1_NUM_SENSORS	3
  
  /* AEM 2.x has more energy registers */
  #define AEM_NUM_ENERGY_REGS	AEM2_NUM_ENERGY_REGS
  /* AEM 2.x needs more sensor files */
  #define AEM_NUM_SENSORS		AEM2_NUM_SENSORS
  
  #define POWER_CAP		0
  #define POWER_CAP_MAX_HOTPLUG	1
  #define POWER_CAP_MAX		2
  #define	POWER_CAP_MIN_WARNING	3
  #define POWER_CAP_MIN		4
  #define	POWER_AUX		5
  
  #define AEM_DEFAULT_POWER_INTERVAL 1000
  #define AEM_MIN_POWER_INTERVAL	200
  #define UJ_PER_MJ		1000L

  static DEFINE_IDA(aem_ida);

  static struct platform_driver aem_driver = {
  	.driver = {
  		.name = DRVNAME,
  		.bus = &platform_bus_type,
  	}

  };
  
  struct aem_ipmi_data {
  	struct completion	read_complete;
  	struct ipmi_addr	address;
  	ipmi_user_t		user;
  	int			interface;
  
  	struct kernel_ipmi_msg	tx_message;
  	long			tx_msgid;
  
  	void			*rx_msg_data;
  	unsigned short		rx_msg_len;
  	unsigned char		rx_result;
  	int			rx_recv_type;
  
  	struct device		*bmc_device;
  };
  
  struct aem_ro_sensor_template {
  	char *label;
  	ssize_t (*show)(struct device *dev,
  			struct device_attribute *devattr,
  			char *buf);
  	int index;
  };
  
  struct aem_rw_sensor_template {
  	char *label;
  	ssize_t (*show)(struct device *dev,
  			struct device_attribute *devattr,
  			char *buf);
  	ssize_t (*set)(struct device *dev,
  		       struct device_attribute *devattr,
  		       const char *buf, size_t count);
  	int index;
  };
  
  struct aem_data {
  	struct list_head	list;
  
  	struct device		*hwmon_dev;
  	struct platform_device	*pdev;
  	struct mutex		lock;
  	char			valid;
  	unsigned long		last_updated;	/* In jiffies */
  	u8			ver_major;
  	u8			ver_minor;
  	u8			module_handle;
  	int			id;
  	struct aem_ipmi_data	ipmi;

  	/* Function and buffer to update sensors */

  	void (*update)(struct aem_data *data);

  	struct aem_read_sensor_resp *rs_resp;

  
  	/*
  	 * AEM 1.x sensors:
  	 * Available sensors:
  	 * Energy meter
  	 * Power meter
  	 *
  	 * AEM 2.x sensors:
  	 * Two energy meters
  	 * Two power meters
  	 * Two temperature sensors
  	 * Six power cap registers
  	 */
  
  	/* sysfs attrs */
  	struct sensor_device_attribute	sensors[AEM_NUM_SENSORS];
  
  	/* energy use in mJ */
  	u64			energy[AEM_NUM_ENERGY_REGS];
  
  	/* power sampling interval in ms */
  	unsigned long		power_period[AEM_NUM_ENERGY_REGS];
  
  	/* Everything past here is for AEM2 only */
  
  	/* power caps in dW */
  	u16			pcap[AEM2_NUM_PCAP_REGS];
  
  	/* exhaust temperature in C */
  	u8			temp[AEM2_NUM_TEMP_REGS];
  };
  
  /* Data structures returned by the AEM firmware */
  struct aem_iana_id {
  	u8			bytes[3];
  };
  static struct aem_iana_id system_x_id = {
  	.bytes = {0x4D, 0x4F, 0x00}
  };
  
  /* These are used to find AEM1 instances */
  struct aem_find_firmware_req {
  	struct aem_iana_id	id;
  	u8			rsvd;

  	__be16			index;
  	__be16			module_type_id;

  } __packed;
  
  struct aem_find_firmware_resp {
  	struct aem_iana_id	id;
  	u8			num_instances;
  } __packed;
  
  /* These are used to find AEM2 instances */
  struct aem_find_instance_req {
  	struct aem_iana_id	id;
  	u8			instance_number;

  	__be16			module_type_id;

  } __packed;
  
  struct aem_find_instance_resp {
  	struct aem_iana_id	id;
  	u8			num_instances;
  	u8			major;
  	u8			minor;
  	u8			module_handle;
  	u16			record_id;
  } __packed;
  
  /* These are used to query sensors */
  struct aem_read_sensor_req {
  	struct aem_iana_id	id;
  	u8			module_handle;
  	u8			element;
  	u8			subcommand;
  	u8			reg;
  	u8			rx_buf_size;
  } __packed;
  
  struct aem_read_sensor_resp {
  	struct aem_iana_id	id;
  	u8			bytes[0];
  } __packed;
  
  /* Data structures to talk to the IPMI layer */
  struct aem_driver_data {
  	struct list_head	aem_devices;
  	struct ipmi_smi_watcher	bmc_events;
  	struct ipmi_user_hndl	ipmi_hndlrs;
  };
  
  static void aem_register_bmc(int iface, struct device *dev);
  static void aem_bmc_gone(int iface);
  static void aem_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);
  
  static void aem_remove_sensors(struct aem_data *data);

  static int aem1_find_sensors(struct aem_data *data);
  static int aem2_find_sensors(struct aem_data *data);
  static void update_aem1_sensors(struct aem_data *data);
  static void update_aem2_sensors(struct aem_data *data);
  
  static struct aem_driver_data driver_data = {
  	.aem_devices = LIST_HEAD_INIT(driver_data.aem_devices),
  	.bmc_events = {
  		.owner = THIS_MODULE,
  		.new_smi = aem_register_bmc,
  		.smi_gone = aem_bmc_gone,
  	},
  	.ipmi_hndlrs = {
  		.ipmi_recv_hndl = aem_msg_handler,
  	},
  };
  
  /* Functions to talk to the IPMI layer */
  
  /* Initialize IPMI address, message buffers and user data */
  static int aem_init_ipmi_data(struct aem_ipmi_data *data, int iface,
  			      struct device *bmc)
  {
  	int err;
  
  	init_completion(&data->read_complete);
  	data->bmc_device = bmc;
  
  	/* Initialize IPMI address */
  	data->address.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;
  	data->address.channel = IPMI_BMC_CHANNEL;
  	data->address.data[0] = 0;
  	data->interface = iface;
  
  	/* Initialize message buffers */
  	data->tx_msgid = 0;
  	data->tx_message.netfn = AEM_NETFN;
  
  	/* Create IPMI messaging interface user */
  	err = ipmi_create_user(data->interface, &driver_data.ipmi_hndlrs,
  			       data, &data->user);
  	if (err < 0) {

  		dev_err(bmc,
  			"Unable to register user with IPMI interface %d
  ",
  			data->interface);

  		return err;

  	}
  
  	return 0;
  }
  
  /* Send an IPMI command */
  static int aem_send_message(struct aem_ipmi_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:
  	dev_err(data->bmc_device, "request_settime=%x
  ", err);
  	return err;
  out:
  	dev_err(data->bmc_device, "validate_addr=%x
  ", err);
  	return err;
  }
  
  /* Dispatch IPMI messages to callers */
  static void aem_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)
  {
  	unsigned short rx_len;
  	struct aem_ipmi_data *data = user_msg_data;
  
  	if (msg->msgid != data->tx_msgid) {

  		dev_err(data->bmc_device,
  			"Mismatch between received msgid (%02x) and transmitted msgid (%02x)!
  ",

  			(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) {
  		rx_len = msg->msg.data_len - 1;
  		if (data->rx_msg_len < rx_len)
  			rx_len = data->rx_msg_len;
  		data->rx_msg_len = rx_len;
  		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);
  }

  /* Sensor support functions */

  /* Read a sensor value; must be called with data->lock held */

  static int aem_read_sensor(struct aem_data *data, u8 elt, u8 reg,
  			   void *buf, size_t size)
  {
  	int rs_size, res;
  	struct aem_read_sensor_req rs_req;

  	/* Use preallocated rx buffer */
  	struct aem_read_sensor_resp *rs_resp = data->rs_resp;

  	struct aem_ipmi_data *ipmi = &data->ipmi;
  
  	/* AEM registers are 1, 2, 4 or 8 bytes */
  	switch (size) {
  	case 1:
  	case 2:
  	case 4:
  	case 8:
  		break;
  	default:
  		return -EINVAL;
  	}
  
  	rs_req.id = system_x_id;
  	rs_req.module_handle = data->module_handle;
  	rs_req.element = elt;
  	rs_req.subcommand = AEM_READ_REGISTER;
  	rs_req.reg = reg;
  	rs_req.rx_buf_size = size;
  
  	ipmi->tx_message.cmd = AEM_ELEMENT_CMD;
  	ipmi->tx_message.data = (char *)&rs_req;
  	ipmi->tx_message.data_len = sizeof(rs_req);
  
  	rs_size = sizeof(*rs_resp) + size;

  	ipmi->rx_msg_data = rs_resp;
  	ipmi->rx_msg_len = rs_size;
  
  	aem_send_message(ipmi);
  
  	res = wait_for_completion_timeout(&ipmi->read_complete, IPMI_TIMEOUT);

  	if (!res) {
  		res = -ETIMEDOUT;
  		goto out;
  	}

  
  	if (ipmi->rx_result || ipmi->rx_msg_len != rs_size ||
  	    memcmp(&rs_resp->id, &system_x_id, sizeof(system_x_id))) {

  		res = -ENOENT;
  		goto out;

  	}
  
  	switch (size) {
  	case 1: {
  		u8 *x = buf;
  		*x = rs_resp->bytes[0];
  		break;
  	}
  	case 2: {
  		u16 *x = buf;

  		*x = be16_to_cpup((__be16 *)rs_resp->bytes);

  		break;
  	}
  	case 4: {
  		u32 *x = buf;

  		*x = be32_to_cpup((__be32 *)rs_resp->bytes);

  		break;
  	}
  	case 8: {
  		u64 *x = buf;

  		*x = be64_to_cpup((__be64 *)rs_resp->bytes);

  		break;
  	}
  	}

  	res = 0;

  out:

  	return res;

  }
  
  /* Update AEM energy registers */

  static void update_aem_energy_one(struct aem_data *data, int which)
  {
  	aem_read_sensor(data, AEM_ENERGY_ELEMENT, which,
  			&data->energy[which], 8);
  }

  static void update_aem_energy(struct aem_data *data)
  {

  	update_aem_energy_one(data, 0);

  	if (data->ver_major < 2)
  		return;

  	update_aem_energy_one(data, 1);

  }
  
  /* Update all AEM1 sensors */
  static void update_aem1_sensors(struct aem_data *data)
  {
  	mutex_lock(&data->lock);
  	if (time_before(jiffies, data->last_updated + REFRESH_INTERVAL) &&
  	    data->valid)
  		goto out;
  
  	update_aem_energy(data);
  out:
  	mutex_unlock(&data->lock);
  }
  
  /* Update all AEM2 sensors */
  static void update_aem2_sensors(struct aem_data *data)
  {
  	int i;
  
  	mutex_lock(&data->lock);
  	if (time_before(jiffies, data->last_updated + REFRESH_INTERVAL) &&
  	    data->valid)
  		goto out;
  
  	update_aem_energy(data);
  	aem_read_sensor(data, AEM_EXHAUST_ELEMENT, 0, &data->temp[0], 1);
  	aem_read_sensor(data, AEM_EXHAUST_ELEMENT, 1, &data->temp[1], 1);
  
  	for (i = POWER_CAP; i <= POWER_AUX; i++)
  		aem_read_sensor(data, AEM_POWER_CAP_ELEMENT, i,
  				&data->pcap[i], 2);
  out:
  	mutex_unlock(&data->lock);
  }
  
  /* Delete an AEM instance */
  static void aem_delete(struct aem_data *data)
  {
  	list_del(&data->list);
  	aem_remove_sensors(data);

  	kfree(data->rs_resp);

  	hwmon_device_unregister(data->hwmon_dev);
  	ipmi_destroy_user(data->ipmi.user);

  	platform_set_drvdata(data->pdev, NULL);

  	platform_device_unregister(data->pdev);

  	ida_simple_remove(&aem_ida, data->id);

  	kfree(data);
  }
  
  /* Probe functions for AEM1 devices */
  
  /* Retrieve version and module handle for an AEM1 instance */
  static int aem_find_aem1_count(struct aem_ipmi_data *data)
  {
  	int res;
  	struct aem_find_firmware_req	ff_req;
  	struct aem_find_firmware_resp	ff_resp;
  
  	ff_req.id = system_x_id;
  	ff_req.index = 0;
  	ff_req.module_type_id = cpu_to_be16(AEM_MODULE_TYPE_ID);
  
  	data->tx_message.cmd = AEM_FIND_FW_CMD;
  	data->tx_message.data = (char *)&ff_req;
  	data->tx_message.data_len = sizeof(ff_req);
  
  	data->rx_msg_data = &ff_resp;
  	data->rx_msg_len = sizeof(ff_resp);
  
  	aem_send_message(data);
  
  	res = wait_for_completion_timeout(&data->read_complete, IPMI_TIMEOUT);
  	if (!res)
  		return -ETIMEDOUT;
  
  	if (data->rx_result || data->rx_msg_len != sizeof(ff_resp) ||
  	    memcmp(&ff_resp.id, &system_x_id, sizeof(system_x_id)))
  		return -ENOENT;
  
  	return ff_resp.num_instances;
  }
  
  /* Find and initialize one AEM1 instance */
  static int aem_init_aem1_inst(struct aem_ipmi_data *probe, u8 module_handle)
  {
  	struct aem_data *data;
  	int i;
  	int res = -ENOMEM;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return res;
  	mutex_init(&data->lock);
  
  	/* Copy instance data */
  	data->ver_major = 1;
  	data->ver_minor = 0;
  	data->module_handle = module_handle;
  	for (i = 0; i < AEM1_NUM_ENERGY_REGS; i++)
  		data->power_period[i] = AEM_DEFAULT_POWER_INTERVAL;
  
  	/* Create sub-device for this fw instance */

  	data->id = ida_simple_get(&aem_ida, 0, 0, GFP_KERNEL);
  	if (data->id < 0)

  		goto id_err;
  
  	data->pdev = platform_device_alloc(DRVNAME, data->id);
  	if (!data->pdev)
  		goto dev_err;

  	data->pdev->dev.driver = &aem_driver.driver;

  
  	res = platform_device_add(data->pdev);
  	if (res)
  		goto ipmi_err;

  	platform_set_drvdata(data->pdev, data);

  
  	/* Set up IPMI interface */

  	res = aem_init_ipmi_data(&data->ipmi, probe->interface,
  				 probe->bmc_device);
  	if (res)

  		goto ipmi_err;
  
  	/* Register with hwmon */
  	data->hwmon_dev = hwmon_device_register(&data->pdev->dev);

  	if (IS_ERR(data->hwmon_dev)) {

  		dev_err(&data->pdev->dev,
  			"Unable to register hwmon device for IPMI interface %d
  ",

  			probe->interface);

  		res = PTR_ERR(data->hwmon_dev);

  		goto hwmon_reg_err;
  	}
  
  	data->update = update_aem1_sensors;

  	data->rs_resp = kzalloc(sizeof(*(data->rs_resp)) + 8, GFP_KERNEL);
  	if (!data->rs_resp) {
  		res = -ENOMEM;
  		goto alloc_resp_err;
  	}

  
  	/* Find sensors */

  	res = aem1_find_sensors(data);
  	if (res)

  		goto sensor_err;
  
  	/* Add to our list of AEM devices */
  	list_add_tail(&data->list, &driver_data.aem_devices);
  
  	dev_info(data->ipmi.bmc_device, "Found AEM v%d.%d at 0x%X
  ",
  		 data->ver_major, data->ver_minor,
  		 data->module_handle);
  	return 0;
  
  sensor_err:

  	kfree(data->rs_resp);
  alloc_resp_err:

  	hwmon_device_unregister(data->hwmon_dev);
  hwmon_reg_err:
  	ipmi_destroy_user(data->ipmi.user);
  ipmi_err:

  	platform_set_drvdata(data->pdev, NULL);

  	platform_device_unregister(data->pdev);
  dev_err:

  	ida_simple_remove(&aem_ida, data->id);

  id_err:
  	kfree(data);
  
  	return res;
  }
  
  /* Find and initialize all AEM1 instances */

  static void aem_init_aem1(struct aem_ipmi_data *probe)

  {
  	int num, i, err;
  
  	num = aem_find_aem1_count(probe);
  	for (i = 0; i < num; i++) {
  		err = aem_init_aem1_inst(probe, i);
  		if (err) {
  			dev_err(probe->bmc_device,
  				"Error %d initializing AEM1 0x%X
  ",
  				err, i);

  		}
  	}

  }
  
  /* Probe functions for AEM2 devices */
  
  /* Retrieve version and module handle for an AEM2 instance */
  static int aem_find_aem2(struct aem_ipmi_data *data,
  			    struct aem_find_instance_resp *fi_resp,
  			    int instance_num)
  {
  	int res;
  	struct aem_find_instance_req fi_req;
  
  	fi_req.id = system_x_id;
  	fi_req.instance_number = instance_num;
  	fi_req.module_type_id = cpu_to_be16(AEM_MODULE_TYPE_ID);
  
  	data->tx_message.cmd = AEM_FW_INSTANCE_CMD;
  	data->tx_message.data = (char *)&fi_req;
  	data->tx_message.data_len = sizeof(fi_req);
  
  	data->rx_msg_data = fi_resp;
  	data->rx_msg_len = sizeof(*fi_resp);
  
  	aem_send_message(data);
  
  	res = wait_for_completion_timeout(&data->read_complete, IPMI_TIMEOUT);
  	if (!res)
  		return -ETIMEDOUT;
  
  	if (data->rx_result || data->rx_msg_len != sizeof(*fi_resp) ||

  	    memcmp(&fi_resp->id, &system_x_id, sizeof(system_x_id)) ||
  	    fi_resp->num_instances <= instance_num)

  		return -ENOENT;
  
  	return 0;
  }
  
  /* Find and initialize one AEM2 instance */
  static int aem_init_aem2_inst(struct aem_ipmi_data *probe,
  			      struct aem_find_instance_resp *fi_resp)
  {
  	struct aem_data *data;
  	int i;
  	int res = -ENOMEM;
  
  	data = kzalloc(sizeof(*data), GFP_KERNEL);
  	if (!data)
  		return res;
  	mutex_init(&data->lock);
  
  	/* Copy instance data */
  	data->ver_major = fi_resp->major;
  	data->ver_minor = fi_resp->minor;
  	data->module_handle = fi_resp->module_handle;
  	for (i = 0; i < AEM2_NUM_ENERGY_REGS; i++)
  		data->power_period[i] = AEM_DEFAULT_POWER_INTERVAL;
  
  	/* Create sub-device for this fw instance */

  	data->id = ida_simple_get(&aem_ida, 0, 0, GFP_KERNEL);
  	if (data->id < 0)

  		goto id_err;
  
  	data->pdev = platform_device_alloc(DRVNAME, data->id);
  	if (!data->pdev)
  		goto dev_err;

  	data->pdev->dev.driver = &aem_driver.driver;

  
  	res = platform_device_add(data->pdev);
  	if (res)
  		goto ipmi_err;

  	platform_set_drvdata(data->pdev, data);

  
  	/* Set up IPMI interface */

  	res = aem_init_ipmi_data(&data->ipmi, probe->interface,
  				 probe->bmc_device);
  	if (res)

  		goto ipmi_err;
  
  	/* Register with hwmon */
  	data->hwmon_dev = hwmon_device_register(&data->pdev->dev);

  	if (IS_ERR(data->hwmon_dev)) {

  		dev_err(&data->pdev->dev,
  			"Unable to register hwmon device for IPMI interface %d
  ",

  			probe->interface);

  		res = PTR_ERR(data->hwmon_dev);

  		goto hwmon_reg_err;
  	}
  
  	data->update = update_aem2_sensors;

  	data->rs_resp = kzalloc(sizeof(*(data->rs_resp)) + 8, GFP_KERNEL);
  	if (!data->rs_resp) {
  		res = -ENOMEM;
  		goto alloc_resp_err;
  	}

  
  	/* Find sensors */

  	res = aem2_find_sensors(data);
  	if (res)

  		goto sensor_err;
  
  	/* Add to our list of AEM devices */
  	list_add_tail(&data->list, &driver_data.aem_devices);
  
  	dev_info(data->ipmi.bmc_device, "Found AEM v%d.%d at 0x%X
  ",
  		 data->ver_major, data->ver_minor,
  		 data->module_handle);
  	return 0;
  
  sensor_err:

  	kfree(data->rs_resp);
  alloc_resp_err:

  	hwmon_device_unregister(data->hwmon_dev);
  hwmon_reg_err:
  	ipmi_destroy_user(data->ipmi.user);
  ipmi_err:

  	platform_set_drvdata(data->pdev, NULL);

  	platform_device_unregister(data->pdev);
  dev_err:

  	ida_simple_remove(&aem_ida, data->id);

  id_err:
  	kfree(data);
  
  	return res;
  }
  
  /* Find and initialize all AEM2 instances */

  static void aem_init_aem2(struct aem_ipmi_data *probe)

  {
  	struct aem_find_instance_resp fi_resp;
  	int err;
  	int i = 0;
  
  	while (!aem_find_aem2(probe, &fi_resp, i)) {
  		if (fi_resp.major != 2) {

  			dev_err(probe->bmc_device,
  				"Unknown AEM v%d; please report this to the maintainer.
  ",

  				fi_resp.major);
  			i++;
  			continue;
  		}
  		err = aem_init_aem2_inst(probe, &fi_resp);
  		if (err) {
  			dev_err(probe->bmc_device,
  				"Error %d initializing AEM2 0x%X
  ",
  				err, fi_resp.module_handle);

  		}
  		i++;
  	}

  }
  
  /* Probe a BMC for AEM firmware instances */
  static void aem_register_bmc(int iface, struct device *dev)
  {
  	struct aem_ipmi_data probe;
  
  	if (aem_init_ipmi_data(&probe, iface, dev))
  		return;
  
  	/* Ignore probe errors; they won't cause problems */
  	aem_init_aem1(&probe);
  	aem_init_aem2(&probe);
  
  	ipmi_destroy_user(probe.user);
  }
  
  /* Handle BMC deletion */
  static void aem_bmc_gone(int iface)
  {
  	struct aem_data *p1, *next1;
  
  	list_for_each_entry_safe(p1, next1, &driver_data.aem_devices, list)
  		if (p1->ipmi.interface == iface)
  			aem_delete(p1);
  }
  
  /* sysfs support functions */
  
  /* AEM device name */
  static ssize_t show_name(struct device *dev, struct device_attribute *devattr,
  			 char *buf)
  {
  	struct aem_data *data = dev_get_drvdata(dev);
  
  	return sprintf(buf, "%s%d
  ", DRVNAME, data->ver_major);
  }
  static SENSOR_DEVICE_ATTR(name, S_IRUGO, show_name, NULL, 0);
  
  /* AEM device version */
  static ssize_t show_version(struct device *dev,
  			    struct device_attribute *devattr,
  			    char *buf)
  {
  	struct aem_data *data = dev_get_drvdata(dev);
  
  	return sprintf(buf, "%d.%d
  ", data->ver_major, data->ver_minor);
  }
  static SENSOR_DEVICE_ATTR(version, S_IRUGO, show_version, NULL, 0);
  
  /* Display power use */
  static ssize_t aem_show_power(struct device *dev,
  			      struct device_attribute *devattr,
  			      char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *data = dev_get_drvdata(dev);
  	u64 before, after, delta, time;
  	signed long leftover;

  
  	mutex_lock(&data->lock);

  	update_aem_energy_one(data, attr->index);

  	time = ktime_get_ns();

  	before = data->energy[attr->index];
  
  	leftover = schedule_timeout_interruptible(
  			msecs_to_jiffies(data->power_period[attr->index])
  		   );
  	if (leftover) {
  		mutex_unlock(&data->lock);
  		return 0;
  	}

  	update_aem_energy_one(data, attr->index);

  	time = ktime_get_ns() - time;

  	after = data->energy[attr->index];
  	mutex_unlock(&data->lock);

  	delta = (after - before) * UJ_PER_MJ;
  
  	return sprintf(buf, "%llu
  ",
  		(unsigned long long)div64_u64(delta * NSEC_PER_SEC, time));
  }
  
  /* Display energy use */
  static ssize_t aem_show_energy(struct device *dev,
  			       struct device_attribute *devattr,
  			       char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *a = dev_get_drvdata(dev);

  	mutex_lock(&a->lock);
  	update_aem_energy_one(a, attr->index);
  	mutex_unlock(&a->lock);

  
  	return sprintf(buf, "%llu
  ",
  			(unsigned long long)a->energy[attr->index] * 1000);
  }
  
  /* Display power interval registers */
  static ssize_t aem_show_power_period(struct device *dev,
  				     struct device_attribute *devattr,
  				     char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *a = dev_get_drvdata(dev);
  	a->update(a);
  
  	return sprintf(buf, "%lu
  ", a->power_period[attr->index]);
  }
  
  /* Set power interval registers */
  static ssize_t aem_set_power_period(struct device *dev,
  				    struct device_attribute *devattr,
  				    const char *buf, size_t count)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *a = dev_get_drvdata(dev);
  	unsigned long temp;
  	int res;

  	res = kstrtoul(buf, 10, &temp);

  	if (res)
  		return res;
  
  	if (temp < AEM_MIN_POWER_INTERVAL)
  		return -EINVAL;
  
  	mutex_lock(&a->lock);
  	a->power_period[attr->index] = temp;
  	mutex_unlock(&a->lock);
  
  	return count;
  }
  
  /* Discover sensors on an AEM device */
  static int aem_register_sensors(struct aem_data *data,

  				const struct aem_ro_sensor_template *ro,
  				const struct aem_rw_sensor_template *rw)

  {
  	struct device *dev = &data->pdev->dev;
  	struct sensor_device_attribute *sensors = data->sensors;
  	int err;
  
  	/* Set up read-only sensors */
  	while (ro->label) {

  		sysfs_attr_init(&sensors->dev_attr.attr);

  		sensors->dev_attr.attr.name = ro->label;
  		sensors->dev_attr.attr.mode = S_IRUGO;
  		sensors->dev_attr.show = ro->show;
  		sensors->index = ro->index;
  
  		err = device_create_file(dev, &sensors->dev_attr);
  		if (err) {
  			sensors->dev_attr.attr.name = NULL;
  			goto error;
  		}
  		sensors++;
  		ro++;
  	}
  
  	/* Set up read-write sensors */
  	while (rw->label) {

  		sysfs_attr_init(&sensors->dev_attr.attr);

  		sensors->dev_attr.attr.name = rw->label;
  		sensors->dev_attr.attr.mode = S_IRUGO | S_IWUSR;
  		sensors->dev_attr.show = rw->show;
  		sensors->dev_attr.store = rw->set;
  		sensors->index = rw->index;
  
  		err = device_create_file(dev, &sensors->dev_attr);
  		if (err) {
  			sensors->dev_attr.attr.name = NULL;
  			goto error;
  		}
  		sensors++;
  		rw++;
  	}
  
  	err = device_create_file(dev, &sensor_dev_attr_name.dev_attr);
  	if (err)
  		goto error;
  	err = device_create_file(dev, &sensor_dev_attr_version.dev_attr);
  	return err;
  
  error:
  	aem_remove_sensors(data);
  	return err;
  }
  
  /* sysfs support functions for AEM2 sensors */
  
  /* Display temperature use */
  static ssize_t aem2_show_temp(struct device *dev,
  			      struct device_attribute *devattr,
  			      char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *a = dev_get_drvdata(dev);
  	a->update(a);
  
  	return sprintf(buf, "%u
  ", a->temp[attr->index] * 1000);
  }
  
  /* Display power-capping registers */
  static ssize_t aem2_show_pcap_value(struct device *dev,
  				    struct device_attribute *devattr,
  				    char *buf)
  {
  	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
  	struct aem_data *a = dev_get_drvdata(dev);
  	a->update(a);
  
  	return sprintf(buf, "%u
  ", a->pcap[attr->index] * 100000);
  }
  
  /* Remove sensors attached to an AEM device */
  static void aem_remove_sensors(struct aem_data *data)
  {
  	int i;
  
  	for (i = 0; i < AEM_NUM_SENSORS; i++) {
  		if (!data->sensors[i].dev_attr.attr.name)
  			continue;
  		device_remove_file(&data->pdev->dev,
  				   &data->sensors[i].dev_attr);
  	}
  
  	device_remove_file(&data->pdev->dev,
  			   &sensor_dev_attr_name.dev_attr);
  	device_remove_file(&data->pdev->dev,
  			   &sensor_dev_attr_version.dev_attr);
  }
  
  /* Sensor probe functions */
  
  /* Description of AEM1 sensors */

  static const struct aem_ro_sensor_template aem1_ro_sensors[] = {

  {"energy1_input",  aem_show_energy, 0},
  {"power1_average", aem_show_power,  0},
  {NULL,		   NULL,	    0},
  };

  static const struct aem_rw_sensor_template aem1_rw_sensors[] = {

  {"power1_average_interval", aem_show_power_period, aem_set_power_period, 0},
  {NULL,			    NULL,                  NULL,                 0},
  };
  
  /* Description of AEM2 sensors */

  static const struct aem_ro_sensor_template aem2_ro_sensors[] = {

  {"energy1_input",	  aem_show_energy,	0},
  {"energy2_input",	  aem_show_energy,	1},
  {"power1_average",	  aem_show_power,	0},
  {"power2_average",	  aem_show_power,	1},
  {"temp1_input",		  aem2_show_temp,	0},
  {"temp2_input",		  aem2_show_temp,	1},
  
  {"power4_average",	  aem2_show_pcap_value,	POWER_CAP_MAX_HOTPLUG},
  {"power5_average",	  aem2_show_pcap_value,	POWER_CAP_MAX},
  {"power6_average",	  aem2_show_pcap_value,	POWER_CAP_MIN_WARNING},
  {"power7_average",	  aem2_show_pcap_value,	POWER_CAP_MIN},

  {"power3_average",	  aem2_show_pcap_value,	POWER_AUX},

  {"power_cap",		  aem2_show_pcap_value,	POWER_CAP},
  {NULL,                    NULL,                 0},
  };

  static const struct aem_rw_sensor_template aem2_rw_sensors[] = {

  {"power1_average_interval", aem_show_power_period, aem_set_power_period, 0},
  {"power2_average_interval", aem_show_power_period, aem_set_power_period, 1},
  {NULL,			    NULL,                  NULL,                 0},
  };
  
  /* Set up AEM1 sensor attrs */
  static int aem1_find_sensors(struct aem_data *data)
  {
  	return aem_register_sensors(data, aem1_ro_sensors, aem1_rw_sensors);
  }
  
  /* Set up AEM2 sensor attrs */
  static int aem2_find_sensors(struct aem_data *data)
  {
  	return aem_register_sensors(data, aem2_ro_sensors, aem2_rw_sensors);
  }
  
  /* Module init/exit routines */
  
  static int __init aem_init(void)
  {
  	int res;

  	res = driver_register(&aem_driver.driver);

  	if (res) {

  		pr_err("Can't register aem driver
  ");

  		return res;
  	}
  
  	res = ipmi_smi_watcher_register(&driver_data.bmc_events);
  	if (res)
  		goto ipmi_reg_err;
  	return 0;
  
  ipmi_reg_err:

  	driver_unregister(&aem_driver.driver);

  	return res;
  
  }
  
  static void __exit aem_exit(void)
  {
  	struct aem_data *p1, *next1;
  
  	ipmi_smi_watcher_unregister(&driver_data.bmc_events);

  	driver_unregister(&aem_driver.driver);

  	list_for_each_entry_safe(p1, next1, &driver_data.aem_devices, list)
  		aem_delete(p1);
  }

  MODULE_AUTHOR("Darrick J. Wong <darrick.wong@oracle.com>");

  MODULE_DESCRIPTION("IBM AEM power/temp/energy sensor driver");

  MODULE_LICENSE("GPL");
  
  module_init(aem_init);
  module_exit(aem_exit);

  
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3350-*");
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3550-*");
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3650-*");
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3655-*");
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMSystemx3755-*");
  MODULE_ALIAS("dmi:bvnIBM:*:pnIBM3850M2/x3950M2-*");

  MODULE_ALIAS("dmi:bvnIBM:*:pnIBMBladeHC10-*");