lineage-pem.c

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/*
 * Driver for Lineage Compact Power Line series of power entry modules.
 *
 * Copyright (C) 2010, 2011 Ericsson AB.
 *
 * Documentation:
 *  http://www.lineagepower.com/oem/pdf/CPLI2C.pdf
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>

/*
 * This driver supports various Lineage Compact Power Line DC/DC and AC/DC
 * converters such as CP1800, CP2000AC, CP2000DC, CP2100DC, and others.
 *
 * The devices are nominally PMBus compliant. However, most standard PMBus
 * commands are not supported. Specifically, all hardware monitoring and
 * status reporting commands are non-standard. For this reason, a standard
 * PMBus driver can not be used.
 *
 * All Lineage CPL devices have a built-in I2C bus master selector (PCA9541).
 * To ensure device access, this driver should only be used as client driver
 * to the pca9541 I2C master selector driver.
 */

/* Command codes */
#define PEM_OPERATION       0x01
#define PEM_CLEAR_INFO_FLAGS    0x03
#define PEM_VOUT_COMMAND    0x21
#define PEM_VOUT_OV_FAULT_LIMIT 0x40
#define PEM_READ_DATA_STRING    0xd0
#define PEM_READ_INPUT_STRING   0xdc
#define PEM_READ_FIRMWARE_REV   0xdd
#define PEM_READ_RUN_TIMER  0xde
#define PEM_FAN_HI_SPEED    0xdf
#define PEM_FAN_NORMAL_SPEED    0xe0
#define PEM_READ_FAN_SPEED  0xe1

/* offsets in data string */
#define PEM_DATA_STATUS_2   0
#define PEM_DATA_STATUS_1   1
#define PEM_DATA_ALARM_2    2
#define PEM_DATA_ALARM_1    3
#define PEM_DATA_VOUT_LSB   4
#define PEM_DATA_VOUT_MSB   5
#define PEM_DATA_CURRENT    6
#define PEM_DATA_TEMP       7

/* Virtual entries, to report constants */
#define PEM_DATA_TEMP_MAX   10
#define PEM_DATA_TEMP_CRIT  11

/* offsets in input string */
#define PEM_INPUT_VOLTAGE   0
#define PEM_INPUT_POWER_LSB 1
#define PEM_INPUT_POWER_MSB 2

/* offsets in fan data */
#define PEM_FAN_ADJUSTMENT  0
#define PEM_FAN_FAN1        1
#define PEM_FAN_FAN2        2
#define PEM_FAN_FAN3        3

/* Status register bits */
#define STS1_OUTPUT_ON      (1 << 0)
#define STS1_LEDS_FLASHING  (1 << 1)
#define STS1_EXT_FAULT      (1 << 2)
#define STS1_SERVICE_LED_ON (1 << 3)
#define STS1_SHUTDOWN_OCCURRED  (1 << 4)
#define STS1_INT_FAULT      (1 << 5)
#define STS1_ISOLATION_TEST_OK  (1 << 6)

#define STS2_ENABLE_PIN_HI  (1 << 0)
#define STS2_DATA_OUT_RANGE (1 << 1)
#define STS2_RESTARTED_OK   (1 << 1)
#define STS2_ISOLATION_TEST_FAIL (1 << 3)
#define STS2_HIGH_POWER_CAP (1 << 4)
#define STS2_INVALID_INSTR  (1 << 5)
#define STS2_WILL_RESTART   (1 << 6)
#define STS2_PEC_ERR        (1 << 7)

/* Alarm register bits */
#define ALRM1_VIN_OUT_LIMIT (1 << 0)
#define ALRM1_VOUT_OUT_LIMIT    (1 << 1)
#define ALRM1_OV_VOLT_SHUTDOWN  (1 << 2)
#define ALRM1_VIN_OVERCURRENT   (1 << 3)
#define ALRM1_TEMP_WARNING  (1 << 4)
#define ALRM1_TEMP_SHUTDOWN (1 << 5)
#define ALRM1_PRIMARY_FAULT (1 << 6)
#define ALRM1_POWER_LIMIT   (1 << 7)

#define ALRM2_5V_OUT_LIMIT  (1 << 1)
#define ALRM2_TEMP_FAULT    (1 << 2)
#define ALRM2_OV_LOW        (1 << 3)
#define ALRM2_DCDC_TEMP_HIGH    (1 << 4)
#define ALRM2_PRI_TEMP_HIGH (1 << 5)
#define ALRM2_NO_PRIMARY    (1 << 6)
#define ALRM2_FAN_FAULT     (1 << 7)

#define FIRMWARE_REV_LEN    4
#define DATA_STRING_LEN     9
#define INPUT_STRING_LEN    5   /* 4 for most devices   */
#define FAN_SPEED_LEN       5

struct pem_data {
    struct device *hwmon_dev;

    struct mutex update_lock;
    bool valid;
    bool fans_supported;
    int input_length;
    unsigned long last_updated; /* in jiffies */

    u8 firmware_rev[FIRMWARE_REV_LEN];
    u8 data_string[DATA_STRING_LEN];
    u8 input_string[INPUT_STRING_LEN];
    u8 fan_speed[FAN_SPEED_LEN];
};

static int pem_read_block(struct i2c_client *client, u8 command, u8 *data,
              int data_len)
{
    u8 block_buffer[I2C_SMBUS_BLOCK_MAX];
    int result;

    result = i2c_smbus_read_block_data(client, command, block_buffer);
    if (unlikely(result < 0))
        goto abort;
    if (unlikely(result == 0xff || result != data_len)) {
        result = -EIO;
        goto abort;
    }
    memcpy(data, block_buffer, data_len);
    result = 0;
abort:
    return result;
}

static struct pem_data *pem_update_device(struct device *dev)
{
    struct i2c_client *client = to_i2c_client(dev);
    struct pem_data *data = i2c_get_clientdata(client);
    struct pem_data *ret = data;

    mutex_lock(&data->update_lock);

    if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
        int result;

        /* Read data string */
        result = pem_read_block(client, PEM_READ_DATA_STRING,
                    data->data_string,
                    sizeof(data->data_string));
        if (unlikely(result < 0)) {
            ret = ERR_PTR(result);
            goto abort;
        }

        /* Read input string */
        if (data->input_length) {
            result = pem_read_block(client, PEM_READ_INPUT_STRING,
                        data->input_string,
                        data->input_length);
            if (unlikely(result < 0)) {
                ret = ERR_PTR(result);
                goto abort;
            }
        }

        /* Read fan speeds */
        if (data->fans_supported) {
            result = pem_read_block(client, PEM_READ_FAN_SPEED,
                        data->fan_speed,
                        sizeof(data->fan_speed));
            if (unlikely(result < 0)) {
                ret = ERR_PTR(result);
                goto abort;
            }
        }

        i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);

        data->last_updated = jiffies;
        data->valid = 1;
    }
abort:
    mutex_unlock(&data->update_lock);
    return ret;
}

static long pem_get_data(u8 *data, int len, int index)
{
    long val;

    switch (index) {
    case PEM_DATA_VOUT_LSB:
        val = (data[index] + (data[index+1] << 8)) * 5 / 2;
        break;
    case PEM_DATA_CURRENT:
        val = data[index] * 200;
        break;
    case PEM_DATA_TEMP:
        val = data[index] * 1000;
        break;
    case PEM_DATA_TEMP_MAX:
        val = 97 * 1000;    /* 97 degrees C per datasheet */
        break;
    case PEM_DATA_TEMP_CRIT:
        val = 107 * 1000;   /* 107 degrees C per datasheet */
        break;
    default:
        WARN_ON_ONCE(1);
        val = 0;
    }
    return val;
}

static long pem_get_input(u8 *data, int len, int index)
{
    long val;

    switch (index) {
    case PEM_INPUT_VOLTAGE:
        if (len == INPUT_STRING_LEN)
            val = (data[index] + (data[index+1] << 8) - 75) * 1000;
        else
            val = (data[index] - 75) * 1000;
        break;
    case PEM_INPUT_POWER_LSB:
        if (len == INPUT_STRING_LEN)
            index++;
        val = (data[index] + (data[index+1] << 8)) * 1000000L;
        break;
    default:
        WARN_ON_ONCE(1);
        val = 0;
    }
    return val;
}

static long pem_get_fan(u8 *data, int len, int index)
{
    long val;

    switch (index) {
    case PEM_FAN_FAN1:
    case PEM_FAN_FAN2:
    case PEM_FAN_FAN3:
        val = data[index] * 100;
        break;
    default:
        WARN_ON_ONCE(1);
        val = 0;
    }
    return val;
}

/*
 * Show boolean, either a fault or an alarm.
 * .nr points to the register, .index is the bit mask to check
 */
static ssize_t pem_show_bool(struct device *dev,
                 struct device_attribute *da, char *buf)
{
    struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
    struct pem_data *data = pem_update_device(dev);
    u8 status;

    if (IS_ERR(data))
        return PTR_ERR(data);

    status = data->data_string[attr->nr] & attr->index;
    return snprintf(buf, PAGE_SIZE, "%d\n", !!status);
}

static ssize_t pem_show_data(struct device *dev, struct device_attribute *da,
                 char *buf)
{
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    struct pem_data *data = pem_update_device(dev);
    long value;

    if (IS_ERR(data))
        return PTR_ERR(data);

    value = pem_get_data(data->data_string, sizeof(data->data_string),
                 attr->index);

    return snprintf(buf, PAGE_SIZE, "%ld\n", value);
}

static ssize_t pem_show_input(struct device *dev, struct device_attribute *da,
                  char *buf)
{
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    struct pem_data *data = pem_update_device(dev);
    long value;

    if (IS_ERR(data))
        return PTR_ERR(data);

    value = pem_get_input(data->input_string, sizeof(data->input_string),
                  attr->index);

    return snprintf(buf, PAGE_SIZE, "%ld\n", value);
}

static ssize_t pem_show_fan(struct device *dev, struct device_attribute *da,
                char *buf)
{
    struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
    struct pem_data *data = pem_update_device(dev);
    long value;

    if (IS_ERR(data))
        return PTR_ERR(data);

    value = pem_get_fan(data->fan_speed, sizeof(data->fan_speed),
                attr->index);

    return snprintf(buf, PAGE_SIZE, "%ld\n", value);
}

/* Voltages */
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, pem_show_data, NULL,
              PEM_DATA_VOUT_LSB);
static SENSOR_DEVICE_ATTR_2(in1_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_VOUT_OUT_LIMIT);
static SENSOR_DEVICE_ATTR_2(in1_crit_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_OV_VOLT_SHUTDOWN);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, pem_show_input, NULL,
              PEM_INPUT_VOLTAGE);
static SENSOR_DEVICE_ATTR_2(in2_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1,
                ALRM1_VIN_OUT_LIMIT | ALRM1_PRIMARY_FAULT);

/* Currents */
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, pem_show_data, NULL,
              PEM_DATA_CURRENT);
static SENSOR_DEVICE_ATTR_2(curr1_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_VIN_OVERCURRENT);

/* Power */
static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, pem_show_input, NULL,
              PEM_INPUT_POWER_LSB);
static SENSOR_DEVICE_ATTR_2(power1_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_POWER_LIMIT);

/* Fans */
static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, pem_show_fan, NULL,
              PEM_FAN_FAN1);
static SENSOR_DEVICE_ATTR(fan2_input, S_IRUGO, pem_show_fan, NULL,
              PEM_FAN_FAN2);
static SENSOR_DEVICE_ATTR(fan3_input, S_IRUGO, pem_show_fan, NULL,
              PEM_FAN_FAN3);
static SENSOR_DEVICE_ATTR_2(fan1_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_2, ALRM2_FAN_FAULT);

/* Temperatures */
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, pem_show_data, NULL,
              PEM_DATA_TEMP);
static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, pem_show_data, NULL,
              PEM_DATA_TEMP_MAX);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, pem_show_data, NULL,
              PEM_DATA_TEMP_CRIT);
static SENSOR_DEVICE_ATTR_2(temp1_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_TEMP_WARNING);
static SENSOR_DEVICE_ATTR_2(temp1_crit_alarm, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_1, ALRM1_TEMP_SHUTDOWN);
static SENSOR_DEVICE_ATTR_2(temp1_fault, S_IRUGO, pem_show_bool, NULL,
                PEM_DATA_ALARM_2, ALRM2_TEMP_FAULT);

static struct attribute *pem_attributes[] = {
    &sensor_dev_attr_in1_input.dev_attr.attr,
    &sensor_dev_attr_in1_alarm.dev_attr.attr,
    &sensor_dev_attr_in1_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_in2_alarm.dev_attr.attr,

    &sensor_dev_attr_curr1_alarm.dev_attr.attr,

    &sensor_dev_attr_power1_alarm.dev_attr.attr,

    &sensor_dev_attr_fan1_alarm.dev_attr.attr,

    &sensor_dev_attr_temp1_input.dev_attr.attr,
    &sensor_dev_attr_temp1_max.dev_attr.attr,
    &sensor_dev_attr_temp1_crit.dev_attr.attr,
    &sensor_dev_attr_temp1_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
    &sensor_dev_attr_temp1_fault.dev_attr.attr,

    NULL,
};

static const struct attribute_group pem_group = {
    .attrs = pem_attributes,
};

static struct attribute *pem_input_attributes[] = {
    &sensor_dev_attr_in2_input.dev_attr.attr,
    &sensor_dev_attr_curr1_input.dev_attr.attr,
    &sensor_dev_attr_power1_input.dev_attr.attr,
};

static const struct attribute_group pem_input_group = {
    .attrs = pem_input_attributes,
};

static struct attribute *pem_fan_attributes[] = {
    &sensor_dev_attr_fan1_input.dev_attr.attr,
    &sensor_dev_attr_fan2_input.dev_attr.attr,
    &sensor_dev_attr_fan3_input.dev_attr.attr,
};

static const struct attribute_group pem_fan_group = {
    .attrs = pem_fan_attributes,
};

static int pem_probe(struct i2c_client *client,
             const struct i2c_device_id *id)
{
    struct i2c_adapter *adapter = client->adapter;
    struct pem_data *data;
    int ret;

    if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BLOCK_DATA
                     | I2C_FUNC_SMBUS_WRITE_BYTE))
        return -ENODEV;

    data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
    if (!data)
        return -ENOMEM;

    i2c_set_clientdata(client, data);
    mutex_init(&data->update_lock);

    /*
     * We use the next two commands to determine if the device is really
     * there.
     */
    ret = pem_read_block(client, PEM_READ_FIRMWARE_REV,
                 data->firmware_rev, sizeof(data->firmware_rev));
    if (ret < 0)
        return ret;

    ret = i2c_smbus_write_byte(client, PEM_CLEAR_INFO_FLAGS);
    if (ret < 0)
        return ret;

    dev_info(&client->dev, "Firmware revision %d.%d.%d\n",
         data->firmware_rev[0], data->firmware_rev[1],
         data->firmware_rev[2]);

    /* Register sysfs hooks */
    ret = sysfs_create_group(&client->dev.kobj, &pem_group);
    if (ret)
        return ret;

    /*
     * Check if input readings are supported.
     * This is the case if we can read input data,
     * and if the returned data is not all zeros.
     * Note that input alarms are always supported.
     */
    ret = pem_read_block(client, PEM_READ_INPUT_STRING,
                 data->input_string,
                 sizeof(data->input_string) - 1);
    if (!ret && (data->input_string[0] || data->input_string[1] ||
             data->input_string[2]))
        data->input_length = sizeof(data->input_string) - 1;
    else if (ret < 0) {
        /* Input string is one byte longer for some devices */
        ret = pem_read_block(client, PEM_READ_INPUT_STRING,
                    data->input_string,
                    sizeof(data->input_string));
        if (!ret && (data->input_string[0] || data->input_string[1] ||
                data->input_string[2] || data->input_string[3]))
            data->input_length = sizeof(data->input_string);
    }
    ret = 0;
    if (data->input_length) {
        ret = sysfs_create_group(&client->dev.kobj, &pem_input_group);
        if (ret)
            goto out_remove_groups;
    }

    /*
     * Check if fan speed readings are supported.
     * This is the case if we can read fan speed data,
     * and if the returned data is not all zeros.
     * Note that the fan alarm is always supported.
     */
    ret = pem_read_block(client, PEM_READ_FAN_SPEED,
                 data->fan_speed,
                 sizeof(data->fan_speed));
    if (!ret && (data->fan_speed[0] || data->fan_speed[1] ||
             data->fan_speed[2] || data->fan_speed[3])) {
        data->fans_supported = true;
        ret = sysfs_create_group(&client->dev.kobj, &pem_fan_group);
        if (ret)
            goto out_remove_groups;
    }

    data->hwmon_dev = hwmon_device_register(&client->dev);
    if (IS_ERR(data->hwmon_dev)) {
        ret = PTR_ERR(data->hwmon_dev);
        goto out_remove_groups;
    }

    return 0;

out_remove_groups:
    sysfs_remove_group(&client->dev.kobj, &pem_input_group);
    sysfs_remove_group(&client->dev.kobj, &pem_fan_group);
    sysfs_remove_group(&client->dev.kobj, &pem_group);
    return ret;
}

static int pem_remove(struct i2c_client *client)
{
    struct pem_data *data = i2c_get_clientdata(client);

    hwmon_device_unregister(data->hwmon_dev);

    sysfs_remove_group(&client->dev.kobj, &pem_input_group);
    sysfs_remove_group(&client->dev.kobj, &pem_fan_group);
    sysfs_remove_group(&client->dev.kobj, &pem_group);

    return 0;
}

static const struct i2c_device_id pem_id[] = {
    {"lineage_pem", 0},
    {}
};
MODULE_DEVICE_TABLE(i2c, pem_id);

static struct i2c_driver pem_driver = {
    .driver = {
           .name = "lineage_pem",
           },
    .probe = pem_probe,
    .remove = pem_remove,
    .id_table = pem_id,
};

module_i2c_driver(pem_driver);

MODULE_AUTHOR("Guenter Roeck <[email protected]>");
MODULE_DESCRIPTION("Lineage CPL PEM hardware monitoring driver");
MODULE_LICENSE("GPL");