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ibmpex.c

/*
 * 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:
      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(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) {
            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 <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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