ibmaem.c

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/*
 * 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 <[email protected]>
 *
 * 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\n", data->interface);
        return -EACCES;
    }

    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\n", err);
    return err;
out:
    dev_err(data->bmc_device, "validate_addr=%x\n", 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)!\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) {
        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\n",
            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\n",
         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\n",
                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\n",
            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\n",
         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.\n",
                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\n",
                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\n", 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\n", 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;
    struct timespec b, a;

    mutex_lock(&data->lock);
    update_aem_energy_one(data, attr->index);
    getnstimeofday(&b);
    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);
    getnstimeofday(&a);
    after = data->energy[attr->index];
    mutex_unlock(&data->lock);

    time = timespec_to_ns(&a) - timespec_to_ns(&b);
    delta = (after - before) * UJ_PER_MJ;

    return sprintf(buf, "%llu\n",
        (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\n",
            (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\n", 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,
                struct aem_ro_sensor_template *ro,
                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\n", 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\n", 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 struct aem_ro_sensor_template aem1_ro_sensors[] = {
{"energy1_input",  aem_show_energy, 0},
{"power1_average", aem_show_power,  0},
{NULL,         NULL,        0},
};

static 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 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 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\n");
        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 <[email protected]>");
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-*");