si4713-i2c: avoid potential buffer overflow on si4713

[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / hwmon / pmbus_core.c

/*
 * Hardware monitoring driver for PMBus devices
 *
 * Copyright (c) 2010, 2011 Ericsson AB.
 *
 * 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/delay.h>
#include <linux/i2c/pmbus.h>
#include "pmbus.h"

/*
 * Constants needed to determine number of sensors, booleans, and labels.
 */
#define PMBUS_MAX_INPUT_SENSORS         11      /* 6*volt, 3*curr, 2*power */
#define PMBUS_VOUT_SENSORS_PER_PAGE     5       /* input, min, max, lcrit,
                                                   crit */
#define PMBUS_IOUT_SENSORS_PER_PAGE     4       /* input, min, max, crit */
#define PMBUS_POUT_SENSORS_PER_PAGE     4       /* input, cap, max, crit */
#define PMBUS_MAX_SENSORS_PER_FAN       1       /* input */
#define PMBUS_MAX_SENSORS_PER_TEMP      5       /* input, min, max, lcrit,
                                                   crit */

#define PMBUS_MAX_INPUT_BOOLEANS        7       /* v: min_alarm, max_alarm,
                                                   lcrit_alarm, crit_alarm;
                                                   c: alarm, crit_alarm;
                                                   p: crit_alarm */
#define PMBUS_VOUT_BOOLEANS_PER_PAGE    4       /* min_alarm, max_alarm,
                                                   lcrit_alarm, crit_alarm */
#define PMBUS_IOUT_BOOLEANS_PER_PAGE    3       /* alarm, lcrit_alarm,
                                                   crit_alarm */
#define PMBUS_POUT_BOOLEANS_PER_PAGE    2       /* alarm, crit_alarm */
#define PMBUS_MAX_BOOLEANS_PER_FAN      2       /* alarm, fault */
#define PMBUS_MAX_BOOLEANS_PER_TEMP     4       /* min_alarm, max_alarm,
                                                   lcrit_alarm, crit_alarm */

#define PMBUS_MAX_INPUT_LABELS          4       /* vin, vcap, iin, pin */

/*
 * status, status_vout, status_iout, status_fans, status_fan34, and status_temp
 * are paged. status_input is unpaged.
 */
#define PB_NUM_STATUS_REG       (PMBUS_PAGES * 6 + 1)

/*
 * Index into status register array, per status register group
 */
#define PB_STATUS_BASE          0
#define PB_STATUS_VOUT_BASE     (PB_STATUS_BASE + PMBUS_PAGES)
#define PB_STATUS_IOUT_BASE     (PB_STATUS_VOUT_BASE + PMBUS_PAGES)
#define PB_STATUS_FAN_BASE      (PB_STATUS_IOUT_BASE + PMBUS_PAGES)
#define PB_STATUS_FAN34_BASE    (PB_STATUS_FAN_BASE + PMBUS_PAGES)
#define PB_STATUS_INPUT_BASE    (PB_STATUS_FAN34_BASE + PMBUS_PAGES)
#define PB_STATUS_TEMP_BASE     (PB_STATUS_INPUT_BASE + 1)

struct pmbus_sensor {
        char name[I2C_NAME_SIZE];       /* sysfs sensor name */
        struct sensor_device_attribute attribute;
        u8 page;                /* page number */
        u8 reg;                 /* register */
        enum pmbus_sensor_classes class;        /* sensor class */
        bool update;            /* runtime sensor update needed */
        int data;               /* Sensor data.
                                   Negative if there was a read error */
};

struct pmbus_boolean {
        char name[I2C_NAME_SIZE];       /* sysfs boolean name */
        struct sensor_device_attribute attribute;
};

struct pmbus_label {
        char name[I2C_NAME_SIZE];       /* sysfs label name */
        struct sensor_device_attribute attribute;
        char label[I2C_NAME_SIZE];      /* label */
};

struct pmbus_data {
        struct device *hwmon_dev;

        u32 flags;              /* from platform data */

        int exponent;           /* linear mode: exponent for output voltages */

        const struct pmbus_driver_info *info;

        int max_attributes;
        int num_attributes;
        struct attribute **attributes;
        struct attribute_group group;

        /*
         * Sensors cover both sensor and limit registers.
         */
        int max_sensors;
        int num_sensors;
        struct pmbus_sensor *sensors;
        /*
         * Booleans are used for alarms.
         * Values are determined from status registers.
         */
        int max_booleans;
        int num_booleans;
        struct pmbus_boolean *booleans;
        /*
         * Labels are used to map generic names (e.g., "in1")
         * to PMBus specific names (e.g., "vin" or "vout1").
         */
        int max_labels;
        int num_labels;
        struct pmbus_label *labels;

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

        /*
         * A single status register covers multiple attributes,
         * so we keep them all together.
         */
        u8 status[PB_NUM_STATUS_REG];

        u8 currpage;
};

int pmbus_set_page(struct i2c_client *client, u8 page)
{
        struct pmbus_data *data = i2c_get_clientdata(client);
        int rv = 0;
        int newpage;

        if (page != data->currpage) {
                rv = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
                newpage = i2c_smbus_read_byte_data(client, PMBUS_PAGE);
                if (newpage != page)
                        rv = -EINVAL;
                else
                        data->currpage = page;
        }
        return rv;
}
EXPORT_SYMBOL_GPL(pmbus_set_page);

static int pmbus_write_byte(struct i2c_client *client, u8 page, u8 value)
{
        int rv;

        rv = pmbus_set_page(client, page);
        if (rv < 0)
                return rv;

        return i2c_smbus_write_byte(client, value);
}

static int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg,
                                 u16 word)
{
        int rv;

        rv = pmbus_set_page(client, page);
        if (rv < 0)
                return rv;

        return i2c_smbus_write_word_data(client, reg, word);
}

int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg)
{
        int rv;

        rv = pmbus_set_page(client, page);
        if (rv < 0)
                return rv;

        return i2c_smbus_read_word_data(client, reg);
}
EXPORT_SYMBOL_GPL(pmbus_read_word_data);

static int pmbus_read_byte_data(struct i2c_client *client, u8 page, u8 reg)
{
        int rv;

        rv = pmbus_set_page(client, page);
        if (rv < 0)
                return rv;

        return i2c_smbus_read_byte_data(client, reg);
}

static void pmbus_clear_fault_page(struct i2c_client *client, int page)
{
        pmbus_write_byte(client, page, PMBUS_CLEAR_FAULTS);
}

void pmbus_clear_faults(struct i2c_client *client)
{
        struct pmbus_data *data = i2c_get_clientdata(client);
        int i;

        for (i = 0; i < data->info->pages; i++)
                pmbus_clear_fault_page(client, i);
}
EXPORT_SYMBOL_GPL(pmbus_clear_faults);

static int pmbus_check_status_cml(struct i2c_client *client, int page)
{
        int status, status2;

        status = pmbus_read_byte_data(client, page, PMBUS_STATUS_BYTE);
        if (status < 0 || (status & PB_STATUS_CML)) {
                status2 = pmbus_read_byte_data(client, page, PMBUS_STATUS_CML);
                if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND))
                        return -EINVAL;
        }
        return 0;
}

bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg)
{
        int rv;
        struct pmbus_data *data = i2c_get_clientdata(client);

        rv = pmbus_read_byte_data(client, page, reg);
        if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
                rv = pmbus_check_status_cml(client, page);
        pmbus_clear_fault_page(client, page);
        return rv >= 0;
}
EXPORT_SYMBOL_GPL(pmbus_check_byte_register);

bool pmbus_check_word_register(struct i2c_client *client, int page, int reg)
{
        int rv;
        struct pmbus_data *data = i2c_get_clientdata(client);

        rv = pmbus_read_word_data(client, page, reg);
        if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
                rv = pmbus_check_status_cml(client, page);
        pmbus_clear_fault_page(client, page);
        return rv >= 0;
}
EXPORT_SYMBOL_GPL(pmbus_check_word_register);

const struct pmbus_driver_info *pmbus_get_driver_info(struct i2c_client *client)
{
        struct pmbus_data *data = i2c_get_clientdata(client);

        return data->info;
}
EXPORT_SYMBOL_GPL(pmbus_get_driver_info);

static int pmbus_get_status(struct i2c_client *client, int page, int reg)
{
        struct pmbus_data *data = i2c_get_clientdata(client);
        const struct pmbus_driver_info *info = data->info;
        int status;

        if (info->get_status) {
                status = info->get_status(client, page, reg);
                if (status != -ENODATA)
                        return status;
        }
        return  pmbus_read_byte_data(client, page, reg);
}

static struct pmbus_data *pmbus_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct pmbus_data *data = i2c_get_clientdata(client);
        const struct pmbus_driver_info *info = data->info;

        mutex_lock(&data->update_lock);
        if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
                int i;

                for (i = 0; i < info->pages; i++)
                        data->status[PB_STATUS_BASE + i]
                            = pmbus_read_byte_data(client, i,
                                                   PMBUS_STATUS_BYTE);
                for (i = 0; i < info->pages; i++) {
                        if (!(info->func[i] & PMBUS_HAVE_STATUS_VOUT))
                                continue;
                        data->status[PB_STATUS_VOUT_BASE + i]
                          = pmbus_get_status(client, i, PMBUS_STATUS_VOUT);
                }
                for (i = 0; i < info->pages; i++) {
                        if (!(info->func[i] & PMBUS_HAVE_STATUS_IOUT))
                                continue;
                        data->status[PB_STATUS_IOUT_BASE + i]
                          = pmbus_get_status(client, i, PMBUS_STATUS_IOUT);
                }
                for (i = 0; i < info->pages; i++) {
                        if (!(info->func[i] & PMBUS_HAVE_STATUS_TEMP))
                                continue;
                        data->status[PB_STATUS_TEMP_BASE + i]
                          = pmbus_get_status(client, i,
                                             PMBUS_STATUS_TEMPERATURE);
                }
                for (i = 0; i < info->pages; i++) {
                        if (!(info->func[i] & PMBUS_HAVE_STATUS_FAN12))
                                continue;
                        data->status[PB_STATUS_FAN_BASE + i]
                          = pmbus_get_status(client, i, PMBUS_STATUS_FAN_12);
                }

                for (i = 0; i < info->pages; i++) {
                        if (!(info->func[i] & PMBUS_HAVE_STATUS_FAN34))
                                continue;
                        data->status[PB_STATUS_FAN34_BASE + i]
                          = pmbus_get_status(client, i, PMBUS_STATUS_FAN_34);
                }

                if (info->func[0] & PMBUS_HAVE_STATUS_INPUT)
                        data->status[PB_STATUS_INPUT_BASE]
                          = pmbus_get_status(client, 0, PMBUS_STATUS_INPUT);

                for (i = 0; i < data->num_sensors; i++) {
                        struct pmbus_sensor *sensor = &data->sensors[i];

                        if (!data->valid || sensor->update)
                                sensor->data
                                    = pmbus_read_word_data(client, sensor->page,
                                                           sensor->reg);
                }
                pmbus_clear_faults(client);
                data->last_updated = jiffies;
                data->valid = 1;
        }
        mutex_unlock(&data->update_lock);
        return data;
}

/*
 * Convert linear sensor values to milli- or micro-units
 * depending on sensor type.
 */
static long pmbus_reg2data_linear(struct pmbus_data *data,
                                  struct pmbus_sensor *sensor)
{
        s16 exponent;
        s32 mantissa;
        long val;

        if (sensor->class == PSC_VOLTAGE_OUT) { /* LINEAR16 */
                exponent = data->exponent;
                mantissa = (u16) sensor->data;
        } else {                                /* LINEAR11 */
                exponent = (sensor->data >> 11) & 0x001f;
                mantissa = sensor->data & 0x07ff;

                if (exponent > 0x0f)
                        exponent |= 0xffe0;     /* sign extend exponent */
                if (mantissa > 0x03ff)
                        mantissa |= 0xfffff800; /* sign extend mantissa */
        }

        val = mantissa;

        /* scale result to milli-units for all sensors except fans */
        if (sensor->class != PSC_FAN)
                val = val * 1000L;

        /* scale result to micro-units for power sensors */
        if (sensor->class == PSC_POWER)
                val = val * 1000L;

        if (exponent >= 0)
                val <<= exponent;
        else
                val >>= -exponent;

        return val;
}

/*
 * Convert direct sensor values to milli- or micro-units
 * depending on sensor type.
 */
static long pmbus_reg2data_direct(struct pmbus_data *data,
                                  struct pmbus_sensor *sensor)
{
        long val = (s16) sensor->data;
        long m, b, R;

        m = data->info->m[sensor->class];
        b = data->info->b[sensor->class];
        R = data->info->R[sensor->class];

        if (m == 0)
                return 0;

        /* X = 1/m * (Y * 10^-R - b) */
        R = -R;
        /* scale result to milli-units for everything but fans */
        if (sensor->class != PSC_FAN) {
                R += 3;
                b *= 1000;
        }

        /* scale result to micro-units for power sensors */
        if (sensor->class == PSC_POWER) {
                R += 3;
                b *= 1000;
        }

        while (R > 0) {
                val *= 10;
                R--;
        }
        while (R < 0) {
                val = DIV_ROUND_CLOSEST(val, 10);
                R++;
        }

        return (val - b) / m;
}

static long pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)
{
        long val;

        if (data->info->direct[sensor->class])
                val = pmbus_reg2data_direct(data, sensor);
        else
                val = pmbus_reg2data_linear(data, sensor);

        return val;
}

#define MAX_MANTISSA    (1023 * 1000)
#define MIN_MANTISSA    (511 * 1000)

static u16 pmbus_data2reg_linear(struct pmbus_data *data,
                                 enum pmbus_sensor_classes class, long val)
{
        s16 exponent = 0, mantissa;
        bool negative = false;

        /* simple case */
        if (val == 0)
                return 0;

        if (class == PSC_VOLTAGE_OUT) {
                /* LINEAR16 does not support negative voltages */
                if (val < 0)
                        return 0;

                /*
                 * For a static exponents, we don't have a choice
                 * but to adjust the value to it.
                 */
                if (data->exponent < 0)
                        val <<= -data->exponent;
                else
                        val >>= data->exponent;
                val = DIV_ROUND_CLOSEST(val, 1000);
                return val & 0xffff;
        }

        if (val < 0) {
                negative = true;
                val = -val;
        }

        /* Power is in uW. Convert to mW before converting. */
        if (class == PSC_POWER)
                val = DIV_ROUND_CLOSEST(val, 1000L);

        /*
         * For simplicity, convert fan data to milli-units
         * before calculating the exponent.
         */
        if (class == PSC_FAN)
                val = val * 1000;

        /* Reduce large mantissa until it fits into 10 bit */
        while (val >= MAX_MANTISSA && exponent < 15) {
                exponent++;
                val >>= 1;
        }
        /* Increase small mantissa to improve precision */
        while (val < MIN_MANTISSA && exponent > -15) {
                exponent--;
                val <<= 1;
        }

        /* Convert mantissa from milli-units to units */
        mantissa = DIV_ROUND_CLOSEST(val, 1000);

        /* Ensure that resulting number is within range */
        if (mantissa > 0x3ff)
                mantissa = 0x3ff;

        /* restore sign */
        if (negative)
                mantissa = -mantissa;

        /* Convert to 5 bit exponent, 11 bit mantissa */
        return (mantissa & 0x7ff) | ((exponent << 11) & 0xf800);
}

static u16 pmbus_data2reg_direct(struct pmbus_data *data,
                                 enum pmbus_sensor_classes class, long val)
{
        long m, b, R;

        m = data->info->m[class];
        b = data->info->b[class];
        R = data->info->R[class];

        /* Power is in uW. Adjust R and b. */
        if (class == PSC_POWER) {
                R -= 3;
                b *= 1000;
        }

        /* Calculate Y = (m * X + b) * 10^R */
        if (class != PSC_FAN) {
                R -= 3;         /* Adjust R and b for data in milli-units */
                b *= 1000;
        }
        val = val * m + b;

        while (R > 0) {
                val *= 10;
                R--;
        }
        while (R < 0) {
                val = DIV_ROUND_CLOSEST(val, 10);
                R++;
        }

        return val;
}

static u16 pmbus_data2reg(struct pmbus_data *data,
                          enum pmbus_sensor_classes class, long val)
{
        u16 regval;

        if (data->info->direct[class])
                regval = pmbus_data2reg_direct(data, class, val);
        else
                regval = pmbus_data2reg_linear(data, class, val);

        return regval;
}

/*
 * Return boolean calculated from converted data.
 * <index> defines a status register index and mask, and optionally
 * two sensor indexes.
 * The upper half-word references the two sensors,
 * two sensor indices.
 * The upper half-word references the two optional sensors,
 * the lower half word references status register and mask.
 * The function returns true if (status[reg] & mask) is true and,
 * if specified, if v1 >= v2.
 * To determine if an object exceeds upper limits, specify <v, limit>.
 * To determine if an object exceeds lower limits, specify <limit, v>.
 *
 * For booleans created with pmbus_add_boolean_reg(), only the lower 16 bits of
 * index are set. s1 and s2 (the sensor index values) are zero in this case.
 * The function returns true if (status[reg] & mask) is true.
 *
 * If the boolean was created with pmbus_add_boolean_cmp(), a comparison against
 * a specified limit has to be performed to determine the boolean result.
 * In this case, the function returns true if v1 >= v2 (where v1 and v2 are
 * sensor values referenced by sensor indices s1 and s2).
 *
 * To determine if an object exceeds upper limits, specify <s1,s2> = <v,limit>.
 * To determine if an object exceeds lower limits, specify <s1,s2> = <limit,v>.
 *
 * If a negative value is stored in any of the referenced registers, this value
 * reflects an error code which will be returned.
 */
static int pmbus_get_boolean(struct pmbus_data *data, int index, int *val)
{
        u8 s1 = (index >> 24) & 0xff;
        u8 s2 = (index >> 16) & 0xff;
        u8 reg = (index >> 8) & 0xff;
        u8 mask = index & 0xff;
        int status;
        u8 regval;

        status = data->status[reg];
        if (status < 0)
                return status;

        regval = status & mask;
        if (!s1 && !s2)
                *val = !!regval;
        else {
                long v1, v2;
                struct pmbus_sensor *sensor1, *sensor2;

                sensor1 = &data->sensors[s1];
                if (sensor1->data < 0)
                        return sensor1->data;
                sensor2 = &data->sensors[s2];
                if (sensor2->data < 0)
                        return sensor2->data;

                v1 = pmbus_reg2data(data, sensor1);
                v2 = pmbus_reg2data(data, sensor2);
                *val = !!(regval && v1 >= v2);
        }
        return 0;
}

static ssize_t pmbus_show_boolean(struct device *dev,
                                  struct device_attribute *da, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        struct pmbus_data *data = pmbus_update_device(dev);
        int val;
        int err;

        err = pmbus_get_boolean(data, attr->index, &val);
        if (err)
                return err;
        return snprintf(buf, PAGE_SIZE, "%d\n", val);
}

static ssize_t pmbus_show_sensor(struct device *dev,
                                 struct device_attribute *da, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
        struct pmbus_data *data = pmbus_update_device(dev);
        struct pmbus_sensor *sensor;

        sensor = &data->sensors[attr->index];
        if (sensor->data < 0)
                return sensor->data;

        return snprintf(buf, PAGE_SIZE, "%ld\n", pmbus_reg2data(data, sensor));
}

static ssize_t pmbus_set_sensor(struct device *dev,
                                struct device_attribute *devattr,
                                const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct i2c_client *client = to_i2c_client(dev);
        struct pmbus_data *data = i2c_get_clientdata(client);
        struct pmbus_sensor *sensor = &data->sensors[attr->index];
        ssize_t rv = count;
        long val = 0;
        int ret;
        u16 regval;

        if (strict_strtol(buf, 10, &val) < 0)
                return -EINVAL;

        mutex_lock(&data->update_lock);
        regval = pmbus_data2reg(data, sensor->class, val);
        ret = pmbus_write_word_data(client, sensor->page, sensor->reg, regval);
        if (ret < 0)
                rv = ret;
        else
                data->sensors[attr->index].data = regval;
        mutex_unlock(&data->update_lock);
        return rv;
}

static ssize_t pmbus_show_label(struct device *dev,
                                struct device_attribute *da, char *buf)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct pmbus_data *data = i2c_get_clientdata(client);
        struct sensor_device_attribute *attr = to_sensor_dev_attr(da);

        return snprintf(buf, PAGE_SIZE, "%s\n",
                        data->labels[attr->index].label);
}

#define PMBUS_ADD_ATTR(data, _name, _idx, _mode, _type, _show, _set)    \
do {                                                                    \
        struct sensor_device_attribute *a                               \
            = &data->_type##s[data->num_##_type##s].attribute;          \
        BUG_ON(data->num_attributes >= data->max_attributes);           \
        sysfs_attr_init(&a->dev_attr.attr);                             \
        a->dev_attr.attr.name = _name;                                  \
        a->dev_attr.attr.mode = _mode;                                  \
        a->dev_attr.show = _show;                                       \
        a->dev_attr.store = _set;                                       \
        a->index = _idx;                                                \
        data->attributes[data->num_attributes] = &a->dev_attr.attr;     \
        data->num_attributes++;                                         \
} while (0)

#define PMBUS_ADD_GET_ATTR(data, _name, _type, _idx)                    \
        PMBUS_ADD_ATTR(data, _name, _idx, S_IRUGO, _type,               \
                       pmbus_show_##_type,  NULL)

#define PMBUS_ADD_SET_ATTR(data, _name, _type, _idx)                    \
        PMBUS_ADD_ATTR(data, _name, _idx, S_IWUSR | S_IRUGO, _type,     \
                       pmbus_show_##_type, pmbus_set_##_type)

static void pmbus_add_boolean(struct pmbus_data *data,
                              const char *name, const char *type, int seq,
                              int idx)
{
        struct pmbus_boolean *boolean;

        BUG_ON(data->num_booleans >= data->max_booleans);

        boolean = &data->booleans[data->num_booleans];

        snprintf(boolean->name, sizeof(boolean->name), "%s%d_%s",
                 name, seq, type);
        PMBUS_ADD_GET_ATTR(data, boolean->name, boolean, idx);
        data->num_booleans++;
}

static void pmbus_add_boolean_reg(struct pmbus_data *data,
                                  const char *name, const char *type,
                                  int seq, int reg, int bit)
{
        pmbus_add_boolean(data, name, type, seq, (reg << 8) | bit);
}

static void pmbus_add_boolean_cmp(struct pmbus_data *data,
                                  const char *name, const char *type,
                                  int seq, int i1, int i2, int reg, int mask)
{
        pmbus_add_boolean(data, name, type, seq,
                          (i1 << 24) | (i2 << 16) | (reg << 8) | mask);
}

static void pmbus_add_sensor(struct pmbus_data *data,
                             const char *name, const char *type, int seq,
                             int page, int reg, enum pmbus_sensor_classes class,
                             bool update, bool readonly)
{
        struct pmbus_sensor *sensor;

        BUG_ON(data->num_sensors >= data->max_sensors);

        sensor = &data->sensors[data->num_sensors];
        snprintf(sensor->name, sizeof(sensor->name), "%s%d_%s",
                 name, seq, type);
        sensor->page = page;
        sensor->reg = reg;
        sensor->class = class;
        sensor->update = update;
        if (readonly)
                PMBUS_ADD_GET_ATTR(data, sensor->name, sensor,
                                   data->num_sensors);
        else
                PMBUS_ADD_SET_ATTR(data, sensor->name, sensor,
                                   data->num_sensors);
        data->num_sensors++;
}

static void pmbus_add_label(struct pmbus_data *data,
                            const char *name, int seq,
                            const char *lstring, int index)
{
        struct pmbus_label *label;

        BUG_ON(data->num_labels >= data->max_labels);

        label = &data->labels[data->num_labels];
        snprintf(label->name, sizeof(label->name), "%s%d_label", name, seq);
        if (!index)
                strncpy(label->label, lstring, sizeof(label->label) - 1);
        else
                snprintf(label->label, sizeof(label->label), "%s%d", lstring,
                         index);

        PMBUS_ADD_GET_ATTR(data, label->name, label, data->num_labels);
        data->num_labels++;
}

static const int pmbus_temp_registers[] = {
        PMBUS_READ_TEMPERATURE_1,
        PMBUS_READ_TEMPERATURE_2,
        PMBUS_READ_TEMPERATURE_3
};

static const int pmbus_temp_flags[] = {
        PMBUS_HAVE_TEMP,
        PMBUS_HAVE_TEMP2,
        PMBUS_HAVE_TEMP3
};

static const int pmbus_fan_registers[] = {
        PMBUS_READ_FAN_SPEED_1,
        PMBUS_READ_FAN_SPEED_2,
        PMBUS_READ_FAN_SPEED_3,
        PMBUS_READ_FAN_SPEED_4
};

static const int pmbus_fan_config_registers[] = {
        PMBUS_FAN_CONFIG_12,
        PMBUS_FAN_CONFIG_12,
        PMBUS_FAN_CONFIG_34,
        PMBUS_FAN_CONFIG_34
};

static const int pmbus_fan_status_registers[] = {
        PMBUS_STATUS_FAN_12,
        PMBUS_STATUS_FAN_12,
        PMBUS_STATUS_FAN_34,
        PMBUS_STATUS_FAN_34
};

static const u32 pmbus_fan_flags[] = {
        PMBUS_HAVE_FAN12,
        PMBUS_HAVE_FAN12,
        PMBUS_HAVE_FAN34,
        PMBUS_HAVE_FAN34
};

static const u32 pmbus_fan_status_flags[] = {
        PMBUS_HAVE_STATUS_FAN12,
        PMBUS_HAVE_STATUS_FAN12,
        PMBUS_HAVE_STATUS_FAN34,
        PMBUS_HAVE_STATUS_FAN34
};

/*
 * Determine maximum number of sensors, booleans, and labels.
 * To keep things simple, only make a rough high estimate.
 */
static void pmbus_find_max_attr(struct i2c_client *client,
                                struct pmbus_data *data)
{
        const struct pmbus_driver_info *info = data->info;
        int page, max_sensors, max_booleans, max_labels;

        max_sensors = PMBUS_MAX_INPUT_SENSORS;
        max_booleans = PMBUS_MAX_INPUT_BOOLEANS;
        max_labels = PMBUS_MAX_INPUT_LABELS;

        for (page = 0; page < info->pages; page++) {
                if (info->func[page] & PMBUS_HAVE_VOUT) {
                        max_sensors += PMBUS_VOUT_SENSORS_PER_PAGE;
                        max_booleans += PMBUS_VOUT_BOOLEANS_PER_PAGE;
                        max_labels++;
                }
                if (info->func[page] & PMBUS_HAVE_IOUT) {
                        max_sensors += PMBUS_IOUT_SENSORS_PER_PAGE;
                        max_booleans += PMBUS_IOUT_BOOLEANS_PER_PAGE;
                        max_labels++;
                }
                if (info->func[page] & PMBUS_HAVE_POUT) {
                        max_sensors += PMBUS_POUT_SENSORS_PER_PAGE;
                        max_booleans += PMBUS_POUT_BOOLEANS_PER_PAGE;
                        max_labels++;
                }
                if (info->func[page] & PMBUS_HAVE_FAN12) {
                        max_sensors += 2 * PMBUS_MAX_SENSORS_PER_FAN;
                        max_booleans += 2 * PMBUS_MAX_BOOLEANS_PER_FAN;
                }
                if (info->func[page] & PMBUS_HAVE_FAN34) {
                        max_sensors += 2 * PMBUS_MAX_SENSORS_PER_FAN;
                        max_booleans += 2 * PMBUS_MAX_BOOLEANS_PER_FAN;
                }
                if (info->func[page] & PMBUS_HAVE_TEMP) {
                        max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
                        max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
                }
                if (info->func[page] & PMBUS_HAVE_TEMP2) {
                        max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
                        max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
                }
                if (info->func[page] & PMBUS_HAVE_TEMP3) {
                        max_sensors += PMBUS_MAX_SENSORS_PER_TEMP;
                        max_booleans += PMBUS_MAX_BOOLEANS_PER_TEMP;
                }
        }
        data->max_sensors = max_sensors;
        data->max_booleans = max_booleans;
        data->max_labels = max_labels;
        data->max_attributes = max_sensors + max_booleans + max_labels;
}

/*
 * Search for attributes. Allocate sensors, booleans, and labels as needed.
 */
static void pmbus_find_attributes(struct i2c_client *client,
                                  struct pmbus_data *data)
{
        const struct pmbus_driver_info *info = data->info;
        int page, i0, i1, in_index;

        /*
         * Input voltage sensors
         */
        in_index = 1;
        if (info->func[0] & PMBUS_HAVE_VIN) {
                bool have_alarm = false;

                i0 = data->num_sensors;
                pmbus_add_label(data, "in", in_index, "vin", 0);
                pmbus_add_sensor(data, "in", "input", in_index, 0,
                                 PMBUS_READ_VIN, PSC_VOLTAGE_IN, true, true);
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_VIN_UV_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "min", in_index,
                                         0, PMBUS_VIN_UV_WARN_LIMIT,
                                         PSC_VOLTAGE_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT) {
                                pmbus_add_boolean_reg(data, "in", "min_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_VOLTAGE_UV_WARNING);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_VIN_UV_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "lcrit", in_index,
                                         0, PMBUS_VIN_UV_FAULT_LIMIT,
                                         PSC_VOLTAGE_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT) {
                                pmbus_add_boolean_reg(data, "in", "lcrit_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_VOLTAGE_UV_FAULT);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_VIN_OV_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "max", in_index,
                                         0, PMBUS_VIN_OV_WARN_LIMIT,
                                         PSC_VOLTAGE_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT) {
                                pmbus_add_boolean_reg(data, "in", "max_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_VOLTAGE_OV_WARNING);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_VIN_OV_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "crit", in_index,
                                         0, PMBUS_VIN_OV_FAULT_LIMIT,
                                         PSC_VOLTAGE_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT) {
                                pmbus_add_boolean_reg(data, "in", "crit_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_VOLTAGE_OV_FAULT);
                                have_alarm = true;
                        }
                }
                /*
                 * Add generic alarm attribute only if there are no individual
                 * attributes.
                 */
                if (!have_alarm)
                        pmbus_add_boolean_reg(data, "in", "alarm",
                                              in_index,
                                              PB_STATUS_BASE,
                                              PB_STATUS_VIN_UV);
                in_index++;
        }
        if (info->func[0] & PMBUS_HAVE_VCAP) {
                pmbus_add_label(data, "in", in_index, "vcap", 0);
                pmbus_add_sensor(data, "in", "input", in_index, 0,
                                 PMBUS_READ_VCAP, PSC_VOLTAGE_IN, true, true);
                in_index++;
        }

        /*
         * Output voltage sensors
         */
        for (page = 0; page < info->pages; page++) {
                bool have_alarm = false;

                if (!(info->func[page] & PMBUS_HAVE_VOUT))
                        continue;

                i0 = data->num_sensors;
                pmbus_add_label(data, "in", in_index, "vout", page + 1);
                pmbus_add_sensor(data, "in", "input", in_index, page,
                                 PMBUS_READ_VOUT, PSC_VOLTAGE_OUT, true, true);
                if (pmbus_check_word_register(client, page,
                                              PMBUS_VOUT_UV_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "min", in_index, page,
                                         PMBUS_VOUT_UV_WARN_LIMIT,
                                         PSC_VOLTAGE_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_VOUT) {
                                pmbus_add_boolean_reg(data, "in", "min_alarm",
                                                      in_index,
                                                      PB_STATUS_VOUT_BASE +
                                                      page,
                                                      PB_VOLTAGE_UV_WARNING);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_VOUT_UV_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "lcrit", in_index, page,
                                         PMBUS_VOUT_UV_FAULT_LIMIT,
                                         PSC_VOLTAGE_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_VOUT) {
                                pmbus_add_boolean_reg(data, "in", "lcrit_alarm",
                                                      in_index,
                                                      PB_STATUS_VOUT_BASE +
                                                      page,
                                                      PB_VOLTAGE_UV_FAULT);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_VOUT_OV_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "max", in_index, page,
                                         PMBUS_VOUT_OV_WARN_LIMIT,
                                         PSC_VOLTAGE_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_VOUT) {
                                pmbus_add_boolean_reg(data, "in", "max_alarm",
                                                      in_index,
                                                      PB_STATUS_VOUT_BASE +
                                                      page,
                                                      PB_VOLTAGE_OV_WARNING);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_VOUT_OV_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "in", "crit", in_index, page,
                                         PMBUS_VOUT_OV_FAULT_LIMIT,
                                         PSC_VOLTAGE_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_VOUT) {
                                pmbus_add_boolean_reg(data, "in", "crit_alarm",
                                                      in_index,
                                                      PB_STATUS_VOUT_BASE +
                                                      page,
                                                      PB_VOLTAGE_OV_FAULT);
                                have_alarm = true;
                        }
                }
                /*
                 * Add generic alarm attribute only if there are no individual
                 * attributes.
                 */
                if (!have_alarm)
                        pmbus_add_boolean_reg(data, "in", "alarm",
                                              in_index,
                                              PB_STATUS_BASE + page,
                                              PB_STATUS_VOUT_OV);
                in_index++;
        }

        /*
         * Current sensors
         */

        /*
         * Input current sensors
         */
        in_index = 1;
        if (info->func[0] & PMBUS_HAVE_IIN) {
                i0 = data->num_sensors;
                pmbus_add_label(data, "curr", in_index, "iin", 0);
                pmbus_add_sensor(data, "curr", "input", in_index, 0,
                                 PMBUS_READ_IIN, PSC_CURRENT_IN, true, true);
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_IIN_OC_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "curr", "max", in_index,
                                         0, PMBUS_IIN_OC_WARN_LIMIT,
                                         PSC_CURRENT_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT) {
                                pmbus_add_boolean_reg(data, "curr", "max_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_IIN_OC_WARNING);
                        }
                }
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_IIN_OC_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "curr", "crit", in_index,
                                         0, PMBUS_IIN_OC_FAULT_LIMIT,
                                         PSC_CURRENT_IN, false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT)
                                pmbus_add_boolean_reg(data, "curr",
                                                      "crit_alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_IIN_OC_FAULT);
                }
                in_index++;
        }

        /*
         * Output current sensors
         */
        for (page = 0; page < info->pages; page++) {
                bool have_alarm = false;

                if (!(info->func[page] & PMBUS_HAVE_IOUT))
                        continue;

                i0 = data->num_sensors;
                pmbus_add_label(data, "curr", in_index, "iout", page + 1);
                pmbus_add_sensor(data, "curr", "input", in_index, page,
                                 PMBUS_READ_IOUT, PSC_CURRENT_OUT, true, true);
                if (pmbus_check_word_register(client, page,
                                              PMBUS_IOUT_OC_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "curr", "max", in_index, page,
                                         PMBUS_IOUT_OC_WARN_LIMIT,
                                         PSC_CURRENT_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_IOUT) {
                                pmbus_add_boolean_reg(data, "curr", "max_alarm",
                                                      in_index,
                                                      PB_STATUS_IOUT_BASE +
                                                      page, PB_IOUT_OC_WARNING);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_IOUT_UC_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "curr", "lcrit", in_index, page,
                                         PMBUS_IOUT_UC_FAULT_LIMIT,
                                         PSC_CURRENT_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_IOUT) {
                                pmbus_add_boolean_reg(data, "curr",
                                                      "lcrit_alarm",
                                                      in_index,
                                                      PB_STATUS_IOUT_BASE +
                                                      page, PB_IOUT_UC_FAULT);
                                have_alarm = true;
                        }
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_IOUT_OC_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "curr", "crit", in_index, page,
                                         PMBUS_IOUT_OC_FAULT_LIMIT,
                                         PSC_CURRENT_OUT, false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_IOUT) {
                                pmbus_add_boolean_reg(data, "curr",
                                                      "crit_alarm",
                                                      in_index,
                                                      PB_STATUS_IOUT_BASE +
                                                      page, PB_IOUT_OC_FAULT);
                                have_alarm = true;
                        }
                }
                /*
                 * Add generic alarm attribute only if there are no individual
                 * attributes.
                 */
                if (!have_alarm)
                        pmbus_add_boolean_reg(data, "curr", "alarm",
                                              in_index,
                                              PB_STATUS_BASE + page,
                                              PB_STATUS_IOUT_OC);
                in_index++;
        }

        /*
         * Power sensors
         */
        /*
         * Input Power sensors
         */
        in_index = 1;
        if (info->func[0] & PMBUS_HAVE_PIN) {
                i0 = data->num_sensors;
                pmbus_add_label(data, "power", in_index, "pin", 0);
                pmbus_add_sensor(data, "power", "input", in_index,
                                 0, PMBUS_READ_PIN, PSC_POWER, true, true);
                if (pmbus_check_word_register(client, 0,
                                              PMBUS_PIN_OP_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "power", "max", in_index,
                                         0, PMBUS_PIN_OP_WARN_LIMIT, PSC_POWER,
                                         false, false);
                        if (info->func[0] & PMBUS_HAVE_STATUS_INPUT)
                                pmbus_add_boolean_reg(data, "power",
                                                      "alarm",
                                                      in_index,
                                                      PB_STATUS_INPUT_BASE,
                                                      PB_PIN_OP_WARNING);
                }
                in_index++;
        }

        /*
         * Output Power sensors
         */
        for (page = 0; page < info->pages; page++) {
                bool need_alarm = false;

                if (!(info->func[page] & PMBUS_HAVE_POUT))
                        continue;

                i0 = data->num_sensors;
                pmbus_add_label(data, "power", in_index, "pout", page + 1);
                pmbus_add_sensor(data, "power", "input", in_index, page,
                                 PMBUS_READ_POUT, PSC_POWER, true, true);
                /*
                 * Per hwmon sysfs API, power_cap is to be used to limit output
                 * power.
                 * We have two registers related to maximum output power,
                 * PMBUS_POUT_MAX and PMBUS_POUT_OP_WARN_LIMIT.
                 * PMBUS_POUT_MAX matches the powerX_cap attribute definition.
                 * There is no attribute in the API to match
                 * PMBUS_POUT_OP_WARN_LIMIT. We use powerX_max for now.
                 */
                if (pmbus_check_word_register(client, page, PMBUS_POUT_MAX)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "power", "cap", in_index, page,
                                         PMBUS_POUT_MAX, PSC_POWER,
                                         false, false);
                        need_alarm = true;
                }
                if (pmbus_check_word_register(client, page,
                                              PMBUS_POUT_OP_WARN_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "power", "max", in_index, page,
                                         PMBUS_POUT_OP_WARN_LIMIT, PSC_POWER,
                                         false, false);
                        need_alarm = true;
                }
                if (need_alarm && (info->func[page] & PMBUS_HAVE_STATUS_IOUT))
                        pmbus_add_boolean_reg(data, "power", "alarm",
                                              in_index,
                                              PB_STATUS_IOUT_BASE + page,
                                              PB_POUT_OP_WARNING
                                              | PB_POWER_LIMITING);

                if (pmbus_check_word_register(client, page,
                                              PMBUS_POUT_OP_FAULT_LIMIT)) {
                        i1 = data->num_sensors;
                        pmbus_add_sensor(data, "power", "crit", in_index, page,
                                         PMBUS_POUT_OP_FAULT_LIMIT, PSC_POWER,
                                         false, false);
                        if (info->func[page] & PMBUS_HAVE_STATUS_IOUT)
                                pmbus_add_boolean_reg(data, "power",
                                                      "crit_alarm",
                                                      in_index,
                                                      PB_STATUS_IOUT_BASE
                                                      + page,
                                                      PB_POUT_OP_FAULT);
                }
                in_index++;
        }

        /*
         * Temperature sensors
         */
        in_index = 1;
        for (page = 0; page < info->pages; page++) {
                int t;

                for (t = 0; t < ARRAY_SIZE(pmbus_temp_registers); t++) {
                        bool have_alarm = false;

                        /*
                         * A PMBus chip may support any combination of
                         * temperature registers on any page. So we can not
                         * abort after a failure to detect a register, but have
                         * to continue checking for all registers on all pages.
                         */
                        if (!(info->func[page] & pmbus_temp_flags[t]))
                                continue;

                        if (!pmbus_check_word_register
                            (client, page, pmbus_temp_registers[t]))
                                continue;

                        i0 = data->num_sensors;
                        pmbus_add_sensor(data, "temp", "input", in_index, page,
                                         pmbus_temp_registers[t],
                                         PSC_TEMPERATURE, true, true);

                        /*
                         * PMBus provides only one status register for TEMP1-3.
                         * Thus, we can not use the status register to determine
                         * which of the three sensors actually caused an alarm.
                         * Always compare current temperature against the limit
                         * registers to determine alarm conditions for a
                         * specific sensor.
                         *
                         * Since there is only one set of limit registers for
                         * up to three temperature sensors, we need to update
                         * all limit registers after the limit was changed for
                         * one of the sensors. This ensures that correct limits
                         * are reported for all temperature sensors.
                         */
                        if (pmbus_check_word_register
                            (client, page, PMBUS_UT_WARN_LIMIT)) {
                                i1 = data->num_sensors;
                                pmbus_add_sensor(data, "temp", "min", in_index,
                                                 page, PMBUS_UT_WARN_LIMIT,
                                                 PSC_TEMPERATURE, true, false);
                                if (info->func[page] & PMBUS_HAVE_STATUS_TEMP) {
                                        pmbus_add_boolean_cmp(data, "temp",
                                                "min_alarm", in_index, i1, i0,
                                                PB_STATUS_TEMP_BASE + page,
                                                PB_TEMP_UT_WARNING);
                                        have_alarm = true;
                                }
                        }
                        if (pmbus_check_word_register(client, page,
                                                      PMBUS_UT_FAULT_LIMIT)) {
                                i1 = data->num_sensors;
                                pmbus_add_sensor(data, "temp", "lcrit",
                                                 in_index, page,
                                                 PMBUS_UT_FAULT_LIMIT,
                                                 PSC_TEMPERATURE, true, false);
                                if (info->func[page] & PMBUS_HAVE_STATUS_TEMP) {
                                        pmbus_add_boolean_cmp(data, "temp",
                                                "lcrit_alarm", in_index, i1, i0,
                                                PB_STATUS_TEMP_BASE + page,
                                                PB_TEMP_UT_FAULT);
                                        have_alarm = true;
                                }
                        }
                        if (pmbus_check_word_register
                            (client, page, PMBUS_OT_WARN_LIMIT)) {
                                i1 = data->num_sensors;
                                pmbus_add_sensor(data, "temp", "max", in_index,
                                                 page, PMBUS_OT_WARN_LIMIT,
                                                 PSC_TEMPERATURE, true, false);
                                if (info->func[page] & PMBUS_HAVE_STATUS_TEMP) {
                                        pmbus_add_boolean_cmp(data, "temp",
                                                "max_alarm", in_index, i0, i1,
                                                PB_STATUS_TEMP_BASE + page,
                                                PB_TEMP_OT_WARNING);
                                        have_alarm = true;
                                }
                        }
                        if (pmbus_check_word_register(client, page,
                                                      PMBUS_OT_FAULT_LIMIT)) {
                                i1 = data->num_sensors;
                                pmbus_add_sensor(data, "temp", "crit", in_index,
                                                 page, PMBUS_OT_FAULT_LIMIT,
                                                 PSC_TEMPERATURE, true, false);
                                if (info->func[page] & PMBUS_HAVE_STATUS_TEMP) {
                                        pmbus_add_boolean_cmp(data, "temp",
                                                "crit_alarm", in_index, i0, i1,
                                                PB_STATUS_TEMP_BASE + page,
                                                PB_TEMP_OT_FAULT);
                                        have_alarm = true;
                                }
                        }
                        /*
                         * Last resort - we were not able to create any alarm
                         * registers. Report alarm for all sensors using the
                         * status register temperature alarm bit.
                         */
                        if (!have_alarm)
                                pmbus_add_boolean_reg(data, "temp", "alarm",
                                                      in_index,
                                                      PB_STATUS_BASE + page,
                                                      PB_STATUS_TEMPERATURE);
                        in_index++;
                }
        }

        /*
         * Fans
         */
        in_index = 1;
        for (page = 0; page < info->pages; page++) {
                int f;

                for (f = 0; f < ARRAY_SIZE(pmbus_fan_registers); f++) {
                        int regval;

                        if (!(info->func[page] & pmbus_fan_flags[f]))
                                break;

                        if (!pmbus_check_word_register(client, page,
                                                       pmbus_fan_registers[f])
                            || !pmbus_check_byte_register(client, page,
                                                pmbus_fan_config_registers[f]))
                                break;

                        /*
                         * Skip fan if not installed.
                         * Each fan configuration register covers multiple fans,
                         * so we have to do some magic.
                         */
                        regval = pmbus_read_byte_data(client, page,
                                pmbus_fan_config_registers[f]);
                        if (regval < 0 ||
                            (!(regval & (PB_FAN_1_INSTALLED >> ((f & 1) * 4)))))
                                continue;

                        i0 = data->num_sensors;
                        pmbus_add_sensor(data, "fan", "input", in_index, page,
                                         pmbus_fan_registers[f], PSC_FAN, true,
                                         true);

                        /*
                         * Each fan status register covers multiple fans,
                         * so we have to do some magic.
                         */
                        if ((info->func[page] & pmbus_fan_status_flags[f]) &&
                            pmbus_check_byte_register(client,
                                        page, pmbus_fan_status_registers[f])) {
                                int base;

                                if (f > 1)      /* fan 3, 4 */
                                        base = PB_STATUS_FAN34_BASE + page;
                                else
                                        base = PB_STATUS_FAN_BASE + page;
                                pmbus_add_boolean_reg(data, "fan", "alarm",
                                        in_index, base,
                                        PB_FAN_FAN1_WARNING >> (f & 1));
                                pmbus_add_boolean_reg(data, "fan", "fault",
                                        in_index, base,
                                        PB_FAN_FAN1_FAULT >> (f & 1));
                        }
                        in_index++;
                }
        }
}

/*
 * Identify chip parameters.
 * This function is called for all chips.
 */
static int pmbus_identify_common(struct i2c_client *client,
                                 struct pmbus_data *data)
{
        int vout_mode = -1, exponent;

        if (pmbus_check_byte_register(client, 0, PMBUS_VOUT_MODE))
                vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE);
        if (vout_mode >= 0 && vout_mode != 0xff) {
                /*
                 * Not all chips support the VOUT_MODE command,
                 * so a failure to read it is not an error.
                 */
                switch (vout_mode >> 5) {
                case 0: /* linear mode      */
                        if (data->info->direct[PSC_VOLTAGE_OUT])
                                return -ENODEV;

                        exponent = vout_mode & 0x1f;
                        /* and sign-extend it */
                        if (exponent & 0x10)
                                exponent |= ~0x1f;
                        data->exponent = exponent;
                        break;
                case 2: /* direct mode      */
                        if (!data->info->direct[PSC_VOLTAGE_OUT])
                                return -ENODEV;
                        break;
                default:
                        return -ENODEV;
                }
        }

        /* Determine maximum number of sensors, booleans, and labels */
        pmbus_find_max_attr(client, data);
        pmbus_clear_fault_page(client, 0);
        return 0;
}

int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
                   struct pmbus_driver_info *info)
{
        const struct pmbus_platform_data *pdata = client->dev.platform_data;
        struct pmbus_data *data;
        int ret;

        if (!info) {
                dev_err(&client->dev, "Missing chip information");
                return -ENODEV;
        }

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE
                                     | I2C_FUNC_SMBUS_BYTE_DATA
                                     | I2C_FUNC_SMBUS_WORD_DATA))
                return -ENODEV;

        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data) {
                dev_err(&client->dev, "No memory to allocate driver data\n");
                return -ENOMEM;
        }

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

        /* Bail out if PMBus status register does not exist. */
        if (i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE) < 0) {
                dev_err(&client->dev, "PMBus status register not found\n");
                ret = -ENODEV;
                goto out_data;
        }

        if (pdata)
                data->flags = pdata->flags;
        data->info = info;

        pmbus_clear_faults(client);

        if (info->identify) {
                ret = (*info->identify)(client, info);
                if (ret < 0) {
                        dev_err(&client->dev, "Chip identification failed\n");
                        goto out_data;
                }
        }

        if (info->pages <= 0 || info->pages > PMBUS_PAGES) {
                dev_err(&client->dev, "Bad number of PMBus pages: %d\n",
                        info->pages);
                ret = -EINVAL;
                goto out_data;
        }
        /*
         * Bail out if more than one page was configured, but we can not
         * select the highest page. This is an indication that the wrong
         * chip type was selected. Better bail out now than keep
         * returning errors later on.
         */
        if (info->pages > 1 && pmbus_set_page(client, info->pages - 1) < 0) {
                dev_err(&client->dev, "Failed to select page %d\n",
                        info->pages - 1);
                ret = -EINVAL;
                goto out_data;
        }

        ret = pmbus_identify_common(client, data);
        if (ret < 0) {
                dev_err(&client->dev, "Failed to identify chip capabilities\n");
                goto out_data;
        }

        ret = -ENOMEM;
        data->sensors = kzalloc(sizeof(struct pmbus_sensor) * data->max_sensors,
                                GFP_KERNEL);
        if (!data->sensors) {
                dev_err(&client->dev, "No memory to allocate sensor data\n");
                goto out_data;
        }

        data->booleans = kzalloc(sizeof(struct pmbus_boolean)
                                 * data->max_booleans, GFP_KERNEL);
        if (!data->booleans) {
                dev_err(&client->dev, "No memory to allocate boolean data\n");
                goto out_sensors;
        }

        data->labels = kzalloc(sizeof(struct pmbus_label) * data->max_labels,
                               GFP_KERNEL);
        if (!data->labels) {
                dev_err(&client->dev, "No memory to allocate label data\n");
                goto out_booleans;
        }

        data->attributes = kzalloc(sizeof(struct attribute *)
                                   * data->max_attributes, GFP_KERNEL);
        if (!data->attributes) {
                dev_err(&client->dev, "No memory to allocate attribute data\n");
                goto out_labels;
        }

        pmbus_find_attributes(client, data);

        /*
         * If there are no attributes, something is wrong.
         * Bail out instead of trying to register nothing.
         */
        if (!data->num_attributes) {
                dev_err(&client->dev, "No attributes found\n");
                ret = -ENODEV;
                goto out_attributes;
        }

        /* Register sysfs hooks */
        data->group.attrs = data->attributes;
        ret = sysfs_create_group(&client->dev.kobj, &data->group);
        if (ret) {
                dev_err(&client->dev, "Failed to create sysfs entries\n");
                goto out_attributes;
        }
        data->hwmon_dev = hwmon_device_register(&client->dev);
        if (IS_ERR(data->hwmon_dev)) {
                ret = PTR_ERR(data->hwmon_dev);
                dev_err(&client->dev, "Failed to register hwmon device\n");
                goto out_hwmon_device_register;
        }
        return 0;

out_hwmon_device_register:
        sysfs_remove_group(&client->dev.kobj, &data->group);
out_attributes:
        kfree(data->attributes);
out_labels:
        kfree(data->labels);
out_booleans:
        kfree(data->booleans);
out_sensors:
        kfree(data->sensors);
out_data:
        kfree(data);
        return ret;
}
EXPORT_SYMBOL_GPL(pmbus_do_probe);

int pmbus_do_remove(struct i2c_client *client)
{
        struct pmbus_data *data = i2c_get_clientdata(client);
        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&client->dev.kobj, &data->group);
        kfree(data->attributes);
        kfree(data->labels);
        kfree(data->booleans);
        kfree(data->sensors);
        kfree(data);
        return 0;
}
EXPORT_SYMBOL_GPL(pmbus_do_remove);

MODULE_AUTHOR("Guenter Roeck");
MODULE_DESCRIPTION("PMBus core driver");
MODULE_LICENSE("GPL");