ibmpex.c

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/*
 * A hwmon driver for the IBM PowerExecutive temperature/power sensors
 * Copyright (C) 2007 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
 */

#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/slab.h>
#include <linux/err.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((__be16 *)&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:
    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;
}

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];

    dev_info(data->bmc_device, "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) {
        dev_err(data->bmc_device, "Error reading sensor %d.\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(struct ibmpex_bmc_data *data,
                   const char *sensor_id, int len)
{
    int i;

    if (data->sensor_major == 2)
        return 1000000;

    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);

    sysfs_attr_init(&data->sensors[sensor].attr[func].dev_attr.attr);
    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,
                            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 = 1000;
        } 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) {
        dev_err(dev, "Insufficient memory for BMC interface.\n");
        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) {
        dev_err(dev, "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)) {
        dev_err(data->bmc_device, "Unable to register hwmon "
            "device for IPMI interface %d\n",
            data->interface);
        goto out_user;
    }

    /* 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) {
        dev_err(data->bmc_device, "Error %d finding sensors\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) {
        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) {
        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 <[email protected]>");
MODULE_DESCRIPTION("IBM PowerExecutive power/temperature sensor driver");
MODULE_LICENSE("GPL");

module_init(ibmpex_init);
module_exit(ibmpex_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-*");