Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / hwmon / pmbus / pmbus_core.c
diff --git a/kernel/drivers/hwmon/pmbus/pmbus_core.c b/kernel/drivers/hwmon/pmbus/pmbus_core.c
new file mode 100644 (file)
index 0000000..f2e47c7
--- /dev/null
@@ -0,0 +1,1921 @@
+/*
+ * Hardware monitoring driver for PMBus devices
+ *
+ * Copyright (c) 2010, 2011 Ericsson AB.
+ * Copyright (c) 2012 Guenter Roeck
+ *
+ * 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>
+#include <linux/i2c/pmbus.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.h>
+#include "pmbus.h"
+
+/*
+ * Number of additional attribute pointers to allocate
+ * with each call to krealloc
+ */
+#define PMBUS_ATTR_ALLOC_SIZE  32
+
+/*
+ * 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_TEMP_BASE    (PB_STATUS_FAN34_BASE + PMBUS_PAGES)
+#define PB_STATUS_INPUT_BASE   (PB_STATUS_TEMP_BASE + PMBUS_PAGES)
+#define PB_STATUS_VMON_BASE    (PB_STATUS_INPUT_BASE + 1)
+
+#define PB_NUM_STATUS_REG      (PB_STATUS_VMON_BASE + 1)
+
+#define PMBUS_NAME_SIZE                24
+
+struct pmbus_sensor {
+       struct pmbus_sensor *next;
+       char name[PMBUS_NAME_SIZE];     /* sysfs sensor name */
+       struct device_attribute attribute;
+       u8 page;                /* page number */
+       u16 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 */
+};
+#define to_pmbus_sensor(_attr) \
+       container_of(_attr, struct pmbus_sensor, attribute)
+
+struct pmbus_boolean {
+       char name[PMBUS_NAME_SIZE];     /* sysfs boolean name */
+       struct sensor_device_attribute attribute;
+       struct pmbus_sensor *s1;
+       struct pmbus_sensor *s2;
+};
+#define to_pmbus_boolean(_attr) \
+       container_of(_attr, struct pmbus_boolean, attribute)
+
+struct pmbus_label {
+       char name[PMBUS_NAME_SIZE];     /* sysfs label name */
+       struct device_attribute attribute;
+       char label[PMBUS_NAME_SIZE];    /* label */
+};
+#define to_pmbus_label(_attr) \
+       container_of(_attr, struct pmbus_label, attribute)
+
+struct pmbus_data {
+       struct device *dev;
+       struct device *hwmon_dev;
+
+       u32 flags;              /* from platform data */
+
+       int exponent[PMBUS_PAGES];
+                               /* linear mode: exponent for output voltages */
+
+       const struct pmbus_driver_info *info;
+
+       int max_attributes;
+       int num_attributes;
+       struct attribute_group group;
+       const struct attribute_group *groups[2];
+
+       struct pmbus_sensor *sensors;
+
+       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 status_register;
+
+       u8 currpage;
+};
+
+void pmbus_clear_cache(struct i2c_client *client)
+{
+       struct pmbus_data *data = i2c_get_clientdata(client);
+
+       data->valid = false;
+}
+EXPORT_SYMBOL_GPL(pmbus_clear_cache);
+
+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 = -EIO;
+               else
+                       data->currpage = page;
+       }
+       return rv;
+}
+EXPORT_SYMBOL_GPL(pmbus_set_page);
+
+int pmbus_write_byte(struct i2c_client *client, int page, u8 value)
+{
+       int rv;
+
+       if (page >= 0) {
+               rv = pmbus_set_page(client, page);
+               if (rv < 0)
+                       return rv;
+       }
+
+       return i2c_smbus_write_byte(client, value);
+}
+EXPORT_SYMBOL_GPL(pmbus_write_byte);
+
+/*
+ * _pmbus_write_byte() is similar to pmbus_write_byte(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_write_byte(struct i2c_client *client, int page, u8 value)
+{
+       struct pmbus_data *data = i2c_get_clientdata(client);
+       const struct pmbus_driver_info *info = data->info;
+       int status;
+
+       if (info->write_byte) {
+               status = info->write_byte(client, page, value);
+               if (status != -ENODATA)
+                       return status;
+       }
+       return pmbus_write_byte(client, page, value);
+}
+
+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);
+}
+EXPORT_SYMBOL_GPL(pmbus_write_word_data);
+
+/*
+ * _pmbus_write_word_data() is similar to pmbus_write_word_data(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_write_word_data(struct i2c_client *client, int page, int reg,
+                                 u16 word)
+{
+       struct pmbus_data *data = i2c_get_clientdata(client);
+       const struct pmbus_driver_info *info = data->info;
+       int status;
+
+       if (info->write_word_data) {
+               status = info->write_word_data(client, page, reg, word);
+               if (status != -ENODATA)
+                       return status;
+       }
+       if (reg >= PMBUS_VIRT_BASE)
+               return -ENXIO;
+       return pmbus_write_word_data(client, page, 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);
+
+/*
+ * _pmbus_read_word_data() is similar to pmbus_read_word_data(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_read_word_data(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->read_word_data) {
+               status = info->read_word_data(client, page, reg);
+               if (status != -ENODATA)
+                       return status;
+       }
+       if (reg >= PMBUS_VIRT_BASE)
+               return -ENXIO;
+       return pmbus_read_word_data(client, page, reg);
+}
+
+int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg)
+{
+       int rv;
+
+       if (page >= 0) {
+               rv = pmbus_set_page(client, page);
+               if (rv < 0)
+                       return rv;
+       }
+
+       return i2c_smbus_read_byte_data(client, reg);
+}
+EXPORT_SYMBOL_GPL(pmbus_read_byte_data);
+
+int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value)
+{
+       int rv;
+
+       rv = pmbus_set_page(client, page);
+       if (rv < 0)
+               return rv;
+
+       return i2c_smbus_write_byte_data(client, reg, value);
+}
+EXPORT_SYMBOL_GPL(pmbus_write_byte_data);
+
+int pmbus_update_byte_data(struct i2c_client *client, int page, u8 reg,
+                          u8 mask, u8 value)
+{
+       unsigned int tmp;
+       int rv;
+
+       rv = pmbus_read_byte_data(client, page, reg);
+       if (rv < 0)
+               return rv;
+
+       tmp = (rv & ~mask) | (value & mask);
+
+       if (tmp != rv)
+               rv = pmbus_write_byte_data(client, page, reg, tmp);
+
+       return rv;
+}
+EXPORT_SYMBOL_GPL(pmbus_update_byte_data);
+
+/*
+ * _pmbus_read_byte_data() is similar to pmbus_read_byte_data(), but checks if
+ * a device specific mapping function exists and calls it if necessary.
+ */
+static int _pmbus_read_byte_data(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->read_byte_data) {
+               status = info->read_byte_data(client, page, reg);
+               if (status != -ENODATA)
+                       return status;
+       }
+       return pmbus_read_byte_data(client, page, 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)
+{
+       struct pmbus_data *data = i2c_get_clientdata(client);
+       int status, status2;
+
+       status = _pmbus_read_byte_data(client, -1, data->status_register);
+       if (status < 0 || (status & PB_STATUS_CML)) {
+               status2 = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_CML);
+               if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND))
+                       return -EIO;
+       }
+       return 0;
+}
+
+static bool pmbus_check_register(struct i2c_client *client,
+                                int (*func)(struct i2c_client *client,
+                                            int page, int reg),
+                                int page, int reg)
+{
+       int rv;
+       struct pmbus_data *data = i2c_get_clientdata(client);
+
+       rv = func(client, page, reg);
+       if (rv >= 0 && !(data->flags & PMBUS_SKIP_STATUS_CHECK))
+               rv = pmbus_check_status_cml(client);
+       pmbus_clear_fault_page(client, -1);
+       return rv >= 0;
+}
+
+bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg)
+{
+       return pmbus_check_register(client, _pmbus_read_byte_data, page, reg);
+}
+EXPORT_SYMBOL_GPL(pmbus_check_byte_register);
+
+bool pmbus_check_word_register(struct i2c_client *client, int page, int reg)
+{
+       return pmbus_check_register(client, _pmbus_read_word_data, page, reg);
+}
+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 struct _pmbus_status {
+       u32 func;
+       u16 base;
+       u16 reg;
+} pmbus_status[] = {
+       { PMBUS_HAVE_STATUS_VOUT, PB_STATUS_VOUT_BASE, PMBUS_STATUS_VOUT },
+       { PMBUS_HAVE_STATUS_IOUT, PB_STATUS_IOUT_BASE, PMBUS_STATUS_IOUT },
+       { PMBUS_HAVE_STATUS_TEMP, PB_STATUS_TEMP_BASE,
+         PMBUS_STATUS_TEMPERATURE },
+       { PMBUS_HAVE_STATUS_FAN12, PB_STATUS_FAN_BASE, PMBUS_STATUS_FAN_12 },
+       { PMBUS_HAVE_STATUS_FAN34, PB_STATUS_FAN34_BASE, PMBUS_STATUS_FAN_34 },
+};
+
+static struct pmbus_data *pmbus_update_device(struct device *dev)
+{
+       struct i2c_client *client = to_i2c_client(dev->parent);
+       struct pmbus_data *data = i2c_get_clientdata(client);
+       const struct pmbus_driver_info *info = data->info;
+       struct pmbus_sensor *sensor;
+
+       mutex_lock(&data->update_lock);
+       if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+               int i, j;
+
+               for (i = 0; i < info->pages; i++) {
+                       data->status[PB_STATUS_BASE + i]
+                           = _pmbus_read_byte_data(client, i,
+                                                   data->status_register);
+                       for (j = 0; j < ARRAY_SIZE(pmbus_status); j++) {
+                               struct _pmbus_status *s = &pmbus_status[j];
+
+                               if (!(info->func[i] & s->func))
+                                       continue;
+                               data->status[s->base + i]
+                                       = _pmbus_read_byte_data(client, i,
+                                                               s->reg);
+                       }
+               }
+
+               if (info->func[0] & PMBUS_HAVE_STATUS_INPUT)
+                       data->status[PB_STATUS_INPUT_BASE]
+                         = _pmbus_read_byte_data(client, 0,
+                                                 PMBUS_STATUS_INPUT);
+
+               if (info->func[0] & PMBUS_HAVE_STATUS_VMON)
+                       data->status[PB_STATUS_VMON_BASE]
+                         = _pmbus_read_byte_data(client, 0,
+                                                 PMBUS_VIRT_STATUS_VMON);
+
+               for (sensor = data->sensors; sensor; sensor = sensor->next) {
+                       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[sensor->page];
+               mantissa = (u16) sensor->data;
+       } else {                                /* LINEAR11 */
+               exponent = ((s16)sensor->data) >> 11;
+               mantissa = ((s16)((sensor->data & 0x7ff) << 5)) >> 5;
+       }
+
+       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;
+}
+
+/*
+ * Convert VID sensor values to milli- or micro-units
+ * depending on sensor type.
+ * We currently only support VR11.
+ */
+static long pmbus_reg2data_vid(struct pmbus_data *data,
+                              struct pmbus_sensor *sensor)
+{
+       long val = sensor->data;
+
+       if (val < 0x02 || val > 0xb2)
+               return 0;
+       return DIV_ROUND_CLOSEST(160000 - (val - 2) * 625, 100);
+}
+
+static long pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)
+{
+       long val;
+
+       switch (data->info->format[sensor->class]) {
+       case direct:
+               val = pmbus_reg2data_direct(data, sensor);
+               break;
+       case vid:
+               val = pmbus_reg2data_vid(data, sensor);
+               break;
+       case linear:
+       default:
+               val = pmbus_reg2data_linear(data, sensor);
+               break;
+       }
+       return val;
+}
+
+#define MAX_MANTISSA   (1023 * 1000)
+#define MIN_MANTISSA   (511 * 1000)
+
+static u16 pmbus_data2reg_linear(struct pmbus_data *data,
+                                struct pmbus_sensor *sensor, long val)
+{
+       s16 exponent = 0, mantissa;
+       bool negative = false;
+
+       /* simple case */
+       if (val == 0)
+               return 0;
+
+       if (sensor->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[sensor->page] < 0)
+                       val <<= -data->exponent[sensor->page];
+               else
+                       val >>= data->exponent[sensor->page];
+               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 (sensor->class == PSC_POWER)
+               val = DIV_ROUND_CLOSEST(val, 1000L);
+
+       /*
+        * For simplicity, convert fan data to milli-units
+        * before calculating the exponent.
+        */
+       if (sensor->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,
+                                struct pmbus_sensor *sensor, long val)
+{
+       long m, b, R;
+
+       m = data->info->m[sensor->class];
+       b = data->info->b[sensor->class];
+       R = data->info->R[sensor->class];
+
+       /* Power is in uW. Adjust R and b. */
+       if (sensor->class == PSC_POWER) {
+               R -= 3;
+               b *= 1000;
+       }
+
+       /* Calculate Y = (m * X + b) * 10^R */
+       if (sensor->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_vid(struct pmbus_data *data,
+                             struct pmbus_sensor *sensor, long val)
+{
+       val = clamp_val(val, 500, 1600);
+
+       return 2 + DIV_ROUND_CLOSEST((1600 - val) * 100, 625);
+}
+
+static u16 pmbus_data2reg(struct pmbus_data *data,
+                         struct pmbus_sensor *sensor, long val)
+{
+       u16 regval;
+
+       switch (data->info->format[sensor->class]) {
+       case direct:
+               regval = pmbus_data2reg_direct(data, sensor, val);
+               break;
+       case vid:
+               regval = pmbus_data2reg_vid(data, sensor, val);
+               break;
+       case linear:
+       default:
+               regval = pmbus_data2reg_linear(data, sensor, val);
+               break;
+       }
+       return regval;
+}
+
+/*
+ * Return boolean calculated from converted data.
+ * <index> defines a status register index and mask.
+ * The mask is in the lower 8 bits, the register index is in bits 8..23.
+ *
+ * The associated pmbus_boolean structure contains optional pointers to two
+ * sensor attributes. If specified, those attributes are compared against each
+ * other to determine if a limit has been exceeded.
+ *
+ * If the sensor attribute pointers are NULL, the function returns true if
+ * (status[reg] & mask) is true.
+ *
+ * If sensor attribute pointers are provided, 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 attribute pointers 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, struct pmbus_boolean *b,
+                            int index)
+{
+       struct pmbus_sensor *s1 = b->s1;
+       struct pmbus_sensor *s2 = b->s2;
+       u16 reg = (index >> 8) & 0xffff;
+       u8 mask = index & 0xff;
+       int ret, status;
+       u8 regval;
+
+       status = data->status[reg];
+       if (status < 0)
+               return status;
+
+       regval = status & mask;
+       if (!s1 && !s2) {
+               ret = !!regval;
+       } else if (!s1 || !s2) {
+               WARN(1, "Bad boolean descriptor %p: s1=%p, s2=%p\n", b, s1, s2);
+               return 0;
+       } else {
+               long v1, v2;
+
+               if (s1->data < 0)
+                       return s1->data;
+               if (s2->data < 0)
+                       return s2->data;
+
+               v1 = pmbus_reg2data(data, s1);
+               v2 = pmbus_reg2data(data, s2);
+               ret = !!(regval && v1 >= v2);
+       }
+       return ret;
+}
+
+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_boolean *boolean = to_pmbus_boolean(attr);
+       struct pmbus_data *data = pmbus_update_device(dev);
+       int val;
+
+       val = pmbus_get_boolean(data, boolean, attr->index);
+       if (val < 0)
+               return val;
+       return snprintf(buf, PAGE_SIZE, "%d\n", val);
+}
+
+static ssize_t pmbus_show_sensor(struct device *dev,
+                                struct device_attribute *devattr, char *buf)
+{
+       struct pmbus_data *data = pmbus_update_device(dev);
+       struct pmbus_sensor *sensor = to_pmbus_sensor(devattr);
+
+       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 i2c_client *client = to_i2c_client(dev->parent);
+       struct pmbus_data *data = i2c_get_clientdata(client);
+       struct pmbus_sensor *sensor = to_pmbus_sensor(devattr);
+       ssize_t rv = count;
+       long val = 0;
+       int ret;
+       u16 regval;
+
+       if (kstrtol(buf, 10, &val) < 0)
+               return -EINVAL;
+
+       mutex_lock(&data->update_lock);
+       regval = pmbus_data2reg(data, sensor, val);
+       ret = _pmbus_write_word_data(client, sensor->page, sensor->reg, regval);
+       if (ret < 0)
+               rv = ret;
+       else
+               sensor->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 pmbus_label *label = to_pmbus_label(da);
+
+       return snprintf(buf, PAGE_SIZE, "%s\n", label->label);
+}
+
+static int pmbus_add_attribute(struct pmbus_data *data, struct attribute *attr)
+{
+       if (data->num_attributes >= data->max_attributes - 1) {
+               int new_max_attrs = data->max_attributes + PMBUS_ATTR_ALLOC_SIZE;
+               void *new_attrs = krealloc(data->group.attrs,
+                                          new_max_attrs * sizeof(void *),
+                                          GFP_KERNEL);
+               if (!new_attrs)
+                       return -ENOMEM;
+               data->group.attrs = new_attrs;
+               data->max_attributes = new_max_attrs;
+       }
+
+       data->group.attrs[data->num_attributes++] = attr;
+       data->group.attrs[data->num_attributes] = NULL;
+       return 0;
+}
+
+static void pmbus_dev_attr_init(struct device_attribute *dev_attr,
+                               const char *name,
+                               umode_t mode,
+                               ssize_t (*show)(struct device *dev,
+                                               struct device_attribute *attr,
+                                               char *buf),
+                               ssize_t (*store)(struct device *dev,
+                                                struct device_attribute *attr,
+                                                const char *buf, size_t count))
+{
+       sysfs_attr_init(&dev_attr->attr);
+       dev_attr->attr.name = name;
+       dev_attr->attr.mode = mode;
+       dev_attr->show = show;
+       dev_attr->store = store;
+}
+
+static void pmbus_attr_init(struct sensor_device_attribute *a,
+                           const char *name,
+                           umode_t mode,
+                           ssize_t (*show)(struct device *dev,
+                                           struct device_attribute *attr,
+                                           char *buf),
+                           ssize_t (*store)(struct device *dev,
+                                            struct device_attribute *attr,
+                                            const char *buf, size_t count),
+                           int idx)
+{
+       pmbus_dev_attr_init(&a->dev_attr, name, mode, show, store);
+       a->index = idx;
+}
+
+static int pmbus_add_boolean(struct pmbus_data *data,
+                            const char *name, const char *type, int seq,
+                            struct pmbus_sensor *s1,
+                            struct pmbus_sensor *s2,
+                            u16 reg, u8 mask)
+{
+       struct pmbus_boolean *boolean;
+       struct sensor_device_attribute *a;
+
+       boolean = devm_kzalloc(data->dev, sizeof(*boolean), GFP_KERNEL);
+       if (!boolean)
+               return -ENOMEM;
+
+       a = &boolean->attribute;
+
+       snprintf(boolean->name, sizeof(boolean->name), "%s%d_%s",
+                name, seq, type);
+       boolean->s1 = s1;
+       boolean->s2 = s2;
+       pmbus_attr_init(a, boolean->name, S_IRUGO, pmbus_show_boolean, NULL,
+                       (reg << 8) | mask);
+
+       return pmbus_add_attribute(data, &a->dev_attr.attr);
+}
+
+static struct pmbus_sensor *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;
+       struct device_attribute *a;
+
+       sensor = devm_kzalloc(data->dev, sizeof(*sensor), GFP_KERNEL);
+       if (!sensor)
+               return NULL;
+       a = &sensor->attribute;
+
+       snprintf(sensor->name, sizeof(sensor->name), "%s%d_%s",
+                name, seq, type);
+       sensor->page = page;
+       sensor->reg = reg;
+       sensor->class = class;
+       sensor->update = update;
+       pmbus_dev_attr_init(a, sensor->name,
+                           readonly ? S_IRUGO : S_IRUGO | S_IWUSR,
+                           pmbus_show_sensor, pmbus_set_sensor);
+
+       if (pmbus_add_attribute(data, &a->attr))
+               return NULL;
+
+       sensor->next = data->sensors;
+       data->sensors = sensor;
+
+       return sensor;
+}
+
+static int pmbus_add_label(struct pmbus_data *data,
+                          const char *name, int seq,
+                          const char *lstring, int index)
+{
+       struct pmbus_label *label;
+       struct device_attribute *a;
+
+       label = devm_kzalloc(data->dev, sizeof(*label), GFP_KERNEL);
+       if (!label)
+               return -ENOMEM;
+
+       a = &label->attribute;
+
+       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_dev_attr_init(a, label->name, S_IRUGO, pmbus_show_label, NULL);
+       return pmbus_add_attribute(data, &a->attr);
+}
+
+/*
+ * Search for attributes. Allocate sensors, booleans, and labels as needed.
+ */
+
+/*
+ * The pmbus_limit_attr structure describes a single limit attribute
+ * and its associated alarm attribute.
+ */
+struct pmbus_limit_attr {
+       u16 reg;                /* Limit register */
+       u16 sbit;               /* Alarm attribute status bit */
+       bool update;            /* True if register needs updates */
+       bool low;               /* True if low limit; for limits with compare
+                                  functions only */
+       const char *attr;       /* Attribute name */
+       const char *alarm;      /* Alarm attribute name */
+};
+
+/*
+ * The pmbus_sensor_attr structure describes one sensor attribute. This
+ * description includes a reference to the associated limit attributes.
+ */
+struct pmbus_sensor_attr {
+       u16 reg;                        /* sensor register */
+       u8 gbit;                        /* generic status bit */
+       u8 nlimit;                      /* # of limit registers */
+       enum pmbus_sensor_classes class;/* sensor class */
+       const char *label;              /* sensor label */
+       bool paged;                     /* true if paged sensor */
+       bool update;                    /* true if update needed */
+       bool compare;                   /* true if compare function needed */
+       u32 func;                       /* sensor mask */
+       u32 sfunc;                      /* sensor status mask */
+       int sbase;                      /* status base register */
+       const struct pmbus_limit_attr *limit;/* limit registers */
+};
+
+/*
+ * Add a set of limit attributes and, if supported, the associated
+ * alarm attributes.
+ * returns 0 if no alarm register found, 1 if an alarm register was found,
+ * < 0 on errors.
+ */
+static int pmbus_add_limit_attrs(struct i2c_client *client,
+                                struct pmbus_data *data,
+                                const struct pmbus_driver_info *info,
+                                const char *name, int index, int page,
+                                struct pmbus_sensor *base,
+                                const struct pmbus_sensor_attr *attr)
+{
+       const struct pmbus_limit_attr *l = attr->limit;
+       int nlimit = attr->nlimit;
+       int have_alarm = 0;
+       int i, ret;
+       struct pmbus_sensor *curr;
+
+       for (i = 0; i < nlimit; i++) {
+               if (pmbus_check_word_register(client, page, l->reg)) {
+                       curr = pmbus_add_sensor(data, name, l->attr, index,
+                                               page, l->reg, attr->class,
+                                               attr->update || l->update,
+                                               false);
+                       if (!curr)
+                               return -ENOMEM;
+                       if (l->sbit && (info->func[page] & attr->sfunc)) {
+                               ret = pmbus_add_boolean(data, name,
+                                       l->alarm, index,
+                                       attr->compare ?  l->low ? curr : base
+                                                     : NULL,
+                                       attr->compare ? l->low ? base : curr
+                                                     : NULL,
+                                       attr->sbase + page, l->sbit);
+                               if (ret)
+                                       return ret;
+                               have_alarm = 1;
+                       }
+               }
+               l++;
+       }
+       return have_alarm;
+}
+
+static int pmbus_add_sensor_attrs_one(struct i2c_client *client,
+                                     struct pmbus_data *data,
+                                     const struct pmbus_driver_info *info,
+                                     const char *name,
+                                     int index, int page,
+                                     const struct pmbus_sensor_attr *attr)
+{
+       struct pmbus_sensor *base;
+       int ret;
+
+       if (attr->label) {
+               ret = pmbus_add_label(data, name, index, attr->label,
+                                     attr->paged ? page + 1 : 0);
+               if (ret)
+                       return ret;
+       }
+       base = pmbus_add_sensor(data, name, "input", index, page, attr->reg,
+                               attr->class, true, true);
+       if (!base)
+               return -ENOMEM;
+       if (attr->sfunc) {
+               ret = pmbus_add_limit_attrs(client, data, info, name,
+                                           index, page, base, attr);
+               if (ret < 0)
+                       return ret;
+               /*
+                * Add generic alarm attribute only if there are no individual
+                * alarm attributes, if there is a global alarm bit, and if
+                * the generic status register for this page is accessible.
+                */
+               if (!ret && attr->gbit &&
+                   pmbus_check_byte_register(client, page,
+                                             data->status_register)) {
+                       ret = pmbus_add_boolean(data, name, "alarm", index,
+                                               NULL, NULL,
+                                               PB_STATUS_BASE + page,
+                                               attr->gbit);
+                       if (ret)
+                               return ret;
+               }
+       }
+       return 0;
+}
+
+static int pmbus_add_sensor_attrs(struct i2c_client *client,
+                                 struct pmbus_data *data,
+                                 const char *name,
+                                 const struct pmbus_sensor_attr *attrs,
+                                 int nattrs)
+{
+       const struct pmbus_driver_info *info = data->info;
+       int index, i;
+       int ret;
+
+       index = 1;
+       for (i = 0; i < nattrs; i++) {
+               int page, pages;
+
+               pages = attrs->paged ? info->pages : 1;
+               for (page = 0; page < pages; page++) {
+                       if (!(info->func[page] & attrs->func))
+                               continue;
+                       ret = pmbus_add_sensor_attrs_one(client, data, info,
+                                                        name, index, page,
+                                                        attrs);
+                       if (ret)
+                               return ret;
+                       index++;
+               }
+               attrs++;
+       }
+       return 0;
+}
+
+static const struct pmbus_limit_attr vin_limit_attrs[] = {
+       {
+               .reg = PMBUS_VIN_UV_WARN_LIMIT,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_VOLTAGE_UV_WARNING,
+       }, {
+               .reg = PMBUS_VIN_UV_FAULT_LIMIT,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_VOLTAGE_UV_FAULT,
+       }, {
+               .reg = PMBUS_VIN_OV_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_VOLTAGE_OV_WARNING,
+       }, {
+               .reg = PMBUS_VIN_OV_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_VOLTAGE_OV_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_VIN_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_VIN_MIN,
+               .update = true,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_VIN_MAX,
+               .update = true,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_VIN_HISTORY,
+               .attr = "reset_history",
+       },
+};
+
+static const struct pmbus_limit_attr vmon_limit_attrs[] = {
+       {
+               .reg = PMBUS_VIRT_VMON_UV_WARN_LIMIT,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_VOLTAGE_UV_WARNING,
+       }, {
+               .reg = PMBUS_VIRT_VMON_UV_FAULT_LIMIT,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_VOLTAGE_UV_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_VMON_OV_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_VOLTAGE_OV_WARNING,
+       }, {
+               .reg = PMBUS_VIRT_VMON_OV_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_VOLTAGE_OV_FAULT,
+       }
+};
+
+static const struct pmbus_limit_attr vout_limit_attrs[] = {
+       {
+               .reg = PMBUS_VOUT_UV_WARN_LIMIT,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_VOLTAGE_UV_WARNING,
+       }, {
+               .reg = PMBUS_VOUT_UV_FAULT_LIMIT,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_VOLTAGE_UV_FAULT,
+       }, {
+               .reg = PMBUS_VOUT_OV_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_VOLTAGE_OV_WARNING,
+       }, {
+               .reg = PMBUS_VOUT_OV_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_VOLTAGE_OV_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_VOUT_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_VOUT_MIN,
+               .update = true,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_VOUT_MAX,
+               .update = true,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_VOUT_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_sensor_attr voltage_attributes[] = {
+       {
+               .reg = PMBUS_READ_VIN,
+               .class = PSC_VOLTAGE_IN,
+               .label = "vin",
+               .func = PMBUS_HAVE_VIN,
+               .sfunc = PMBUS_HAVE_STATUS_INPUT,
+               .sbase = PB_STATUS_INPUT_BASE,
+               .gbit = PB_STATUS_VIN_UV,
+               .limit = vin_limit_attrs,
+               .nlimit = ARRAY_SIZE(vin_limit_attrs),
+       }, {
+               .reg = PMBUS_VIRT_READ_VMON,
+               .class = PSC_VOLTAGE_IN,
+               .label = "vmon",
+               .func = PMBUS_HAVE_VMON,
+               .sfunc = PMBUS_HAVE_STATUS_VMON,
+               .sbase = PB_STATUS_VMON_BASE,
+               .limit = vmon_limit_attrs,
+               .nlimit = ARRAY_SIZE(vmon_limit_attrs),
+       }, {
+               .reg = PMBUS_READ_VCAP,
+               .class = PSC_VOLTAGE_IN,
+               .label = "vcap",
+               .func = PMBUS_HAVE_VCAP,
+       }, {
+               .reg = PMBUS_READ_VOUT,
+               .class = PSC_VOLTAGE_OUT,
+               .label = "vout",
+               .paged = true,
+               .func = PMBUS_HAVE_VOUT,
+               .sfunc = PMBUS_HAVE_STATUS_VOUT,
+               .sbase = PB_STATUS_VOUT_BASE,
+               .gbit = PB_STATUS_VOUT_OV,
+               .limit = vout_limit_attrs,
+               .nlimit = ARRAY_SIZE(vout_limit_attrs),
+       }
+};
+
+/* Current attributes */
+
+static const struct pmbus_limit_attr iin_limit_attrs[] = {
+       {
+               .reg = PMBUS_IIN_OC_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_IIN_OC_WARNING,
+       }, {
+               .reg = PMBUS_IIN_OC_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_IIN_OC_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_IIN_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_IIN_MIN,
+               .update = true,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_IIN_MAX,
+               .update = true,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_IIN_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_limit_attr iout_limit_attrs[] = {
+       {
+               .reg = PMBUS_IOUT_OC_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_IOUT_OC_WARNING,
+       }, {
+               .reg = PMBUS_IOUT_UC_FAULT_LIMIT,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_IOUT_UC_FAULT,
+       }, {
+               .reg = PMBUS_IOUT_OC_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_IOUT_OC_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_IOUT_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_IOUT_MIN,
+               .update = true,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_IOUT_MAX,
+               .update = true,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_IOUT_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_sensor_attr current_attributes[] = {
+       {
+               .reg = PMBUS_READ_IIN,
+               .class = PSC_CURRENT_IN,
+               .label = "iin",
+               .func = PMBUS_HAVE_IIN,
+               .sfunc = PMBUS_HAVE_STATUS_INPUT,
+               .sbase = PB_STATUS_INPUT_BASE,
+               .limit = iin_limit_attrs,
+               .nlimit = ARRAY_SIZE(iin_limit_attrs),
+       }, {
+               .reg = PMBUS_READ_IOUT,
+               .class = PSC_CURRENT_OUT,
+               .label = "iout",
+               .paged = true,
+               .func = PMBUS_HAVE_IOUT,
+               .sfunc = PMBUS_HAVE_STATUS_IOUT,
+               .sbase = PB_STATUS_IOUT_BASE,
+               .gbit = PB_STATUS_IOUT_OC,
+               .limit = iout_limit_attrs,
+               .nlimit = ARRAY_SIZE(iout_limit_attrs),
+       }
+};
+
+/* Power attributes */
+
+static const struct pmbus_limit_attr pin_limit_attrs[] = {
+       {
+               .reg = PMBUS_PIN_OP_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "alarm",
+               .sbit = PB_PIN_OP_WARNING,
+       }, {
+               .reg = PMBUS_VIRT_READ_PIN_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_PIN_MAX,
+               .update = true,
+               .attr = "input_highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_PIN_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_limit_attr pout_limit_attrs[] = {
+       {
+               .reg = PMBUS_POUT_MAX,
+               .attr = "cap",
+               .alarm = "cap_alarm",
+               .sbit = PB_POWER_LIMITING,
+       }, {
+               .reg = PMBUS_POUT_OP_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_POUT_OP_WARNING,
+       }, {
+               .reg = PMBUS_POUT_OP_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_POUT_OP_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_POUT_AVG,
+               .update = true,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_POUT_MAX,
+               .update = true,
+               .attr = "input_highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_POUT_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_sensor_attr power_attributes[] = {
+       {
+               .reg = PMBUS_READ_PIN,
+               .class = PSC_POWER,
+               .label = "pin",
+               .func = PMBUS_HAVE_PIN,
+               .sfunc = PMBUS_HAVE_STATUS_INPUT,
+               .sbase = PB_STATUS_INPUT_BASE,
+               .limit = pin_limit_attrs,
+               .nlimit = ARRAY_SIZE(pin_limit_attrs),
+       }, {
+               .reg = PMBUS_READ_POUT,
+               .class = PSC_POWER,
+               .label = "pout",
+               .paged = true,
+               .func = PMBUS_HAVE_POUT,
+               .sfunc = PMBUS_HAVE_STATUS_IOUT,
+               .sbase = PB_STATUS_IOUT_BASE,
+               .limit = pout_limit_attrs,
+               .nlimit = ARRAY_SIZE(pout_limit_attrs),
+       }
+};
+
+/* Temperature atributes */
+
+static const struct pmbus_limit_attr temp_limit_attrs[] = {
+       {
+               .reg = PMBUS_UT_WARN_LIMIT,
+               .low = true,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_TEMP_UT_WARNING,
+       }, {
+               .reg = PMBUS_UT_FAULT_LIMIT,
+               .low = true,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_TEMP_UT_FAULT,
+       }, {
+               .reg = PMBUS_OT_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_TEMP_OT_WARNING,
+       }, {
+               .reg = PMBUS_OT_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_TEMP_OT_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP_MIN,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP_AVG,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP_MAX,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_TEMP_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_limit_attr temp_limit_attrs2[] = {
+       {
+               .reg = PMBUS_UT_WARN_LIMIT,
+               .low = true,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_TEMP_UT_WARNING,
+       }, {
+               .reg = PMBUS_UT_FAULT_LIMIT,
+               .low = true,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_TEMP_UT_FAULT,
+       }, {
+               .reg = PMBUS_OT_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_TEMP_OT_WARNING,
+       }, {
+               .reg = PMBUS_OT_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_TEMP_OT_FAULT,
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP2_MIN,
+               .attr = "lowest",
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP2_AVG,
+               .attr = "average",
+       }, {
+               .reg = PMBUS_VIRT_READ_TEMP2_MAX,
+               .attr = "highest",
+       }, {
+               .reg = PMBUS_VIRT_RESET_TEMP2_HISTORY,
+               .attr = "reset_history",
+       }
+};
+
+static const struct pmbus_limit_attr temp_limit_attrs3[] = {
+       {
+               .reg = PMBUS_UT_WARN_LIMIT,
+               .low = true,
+               .attr = "min",
+               .alarm = "min_alarm",
+               .sbit = PB_TEMP_UT_WARNING,
+       }, {
+               .reg = PMBUS_UT_FAULT_LIMIT,
+               .low = true,
+               .attr = "lcrit",
+               .alarm = "lcrit_alarm",
+               .sbit = PB_TEMP_UT_FAULT,
+       }, {
+               .reg = PMBUS_OT_WARN_LIMIT,
+               .attr = "max",
+               .alarm = "max_alarm",
+               .sbit = PB_TEMP_OT_WARNING,
+       }, {
+               .reg = PMBUS_OT_FAULT_LIMIT,
+               .attr = "crit",
+               .alarm = "crit_alarm",
+               .sbit = PB_TEMP_OT_FAULT,
+       }
+};
+
+static const struct pmbus_sensor_attr temp_attributes[] = {
+       {
+               .reg = PMBUS_READ_TEMPERATURE_1,
+               .class = PSC_TEMPERATURE,
+               .paged = true,
+               .update = true,
+               .compare = true,
+               .func = PMBUS_HAVE_TEMP,
+               .sfunc = PMBUS_HAVE_STATUS_TEMP,
+               .sbase = PB_STATUS_TEMP_BASE,
+               .gbit = PB_STATUS_TEMPERATURE,
+               .limit = temp_limit_attrs,
+               .nlimit = ARRAY_SIZE(temp_limit_attrs),
+       }, {
+               .reg = PMBUS_READ_TEMPERATURE_2,
+               .class = PSC_TEMPERATURE,
+               .paged = true,
+               .update = true,
+               .compare = true,
+               .func = PMBUS_HAVE_TEMP2,
+               .sfunc = PMBUS_HAVE_STATUS_TEMP,
+               .sbase = PB_STATUS_TEMP_BASE,
+               .gbit = PB_STATUS_TEMPERATURE,
+               .limit = temp_limit_attrs2,
+               .nlimit = ARRAY_SIZE(temp_limit_attrs2),
+       }, {
+               .reg = PMBUS_READ_TEMPERATURE_3,
+               .class = PSC_TEMPERATURE,
+               .paged = true,
+               .update = true,
+               .compare = true,
+               .func = PMBUS_HAVE_TEMP3,
+               .sfunc = PMBUS_HAVE_STATUS_TEMP,
+               .sbase = PB_STATUS_TEMP_BASE,
+               .gbit = PB_STATUS_TEMPERATURE,
+               .limit = temp_limit_attrs3,
+               .nlimit = ARRAY_SIZE(temp_limit_attrs3),
+       }
+};
+
+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
+};
+
+/* Fans */
+static int pmbus_add_fan_attributes(struct i2c_client *client,
+                                   struct pmbus_data *data)
+{
+       const struct pmbus_driver_info *info = data->info;
+       int index = 1;
+       int page;
+       int ret;
+
+       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]))
+                               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;
+
+                       if (pmbus_add_sensor(data, "fan", "input", index,
+                                            page, pmbus_fan_registers[f],
+                                            PSC_FAN, true, true) == NULL)
+                               return -ENOMEM;
+
+                       /*
+                        * 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;
+                               ret = pmbus_add_boolean(data, "fan",
+                                       "alarm", index, NULL, NULL, base,
+                                       PB_FAN_FAN1_WARNING >> (f & 1));
+                               if (ret)
+                                       return ret;
+                               ret = pmbus_add_boolean(data, "fan",
+                                       "fault", index, NULL, NULL, base,
+                                       PB_FAN_FAN1_FAULT >> (f & 1));
+                               if (ret)
+                                       return ret;
+                       }
+                       index++;
+               }
+       }
+       return 0;
+}
+
+static int pmbus_find_attributes(struct i2c_client *client,
+                                struct pmbus_data *data)
+{
+       int ret;
+
+       /* Voltage sensors */
+       ret = pmbus_add_sensor_attrs(client, data, "in", voltage_attributes,
+                                    ARRAY_SIZE(voltage_attributes));
+       if (ret)
+               return ret;
+
+       /* Current sensors */
+       ret = pmbus_add_sensor_attrs(client, data, "curr", current_attributes,
+                                    ARRAY_SIZE(current_attributes));
+       if (ret)
+               return ret;
+
+       /* Power sensors */
+       ret = pmbus_add_sensor_attrs(client, data, "power", power_attributes,
+                                    ARRAY_SIZE(power_attributes));
+       if (ret)
+               return ret;
+
+       /* Temperature sensors */
+       ret = pmbus_add_sensor_attrs(client, data, "temp", temp_attributes,
+                                    ARRAY_SIZE(temp_attributes));
+       if (ret)
+               return ret;
+
+       /* Fans */
+       ret = pmbus_add_fan_attributes(client, data);
+       return ret;
+}
+
+/*
+ * Identify chip parameters.
+ * This function is called for all chips.
+ */
+static int pmbus_identify_common(struct i2c_client *client,
+                                struct pmbus_data *data, int page)
+{
+       int vout_mode = -1;
+
+       if (pmbus_check_byte_register(client, page, PMBUS_VOUT_MODE))
+               vout_mode = _pmbus_read_byte_data(client, page,
+                                                 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->format[PSC_VOLTAGE_OUT] != linear)
+                               return -ENODEV;
+
+                       data->exponent[page] = ((s8)(vout_mode << 3)) >> 3;
+                       break;
+               case 1: /* VID mode         */
+                       if (data->info->format[PSC_VOLTAGE_OUT] != vid)
+                               return -ENODEV;
+                       break;
+               case 2: /* direct mode      */
+                       if (data->info->format[PSC_VOLTAGE_OUT] != direct)
+                               return -ENODEV;
+                       break;
+               default:
+                       return -ENODEV;
+               }
+       }
+
+       pmbus_clear_fault_page(client, page);
+       return 0;
+}
+
+static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data,
+                            struct pmbus_driver_info *info)
+{
+       struct device *dev = &client->dev;
+       int page, ret;
+
+       /*
+        * Some PMBus chips don't support PMBUS_STATUS_BYTE, so try
+        * to use PMBUS_STATUS_WORD instead if that is the case.
+        * Bail out if both registers are not supported.
+        */
+       data->status_register = PMBUS_STATUS_BYTE;
+       ret = i2c_smbus_read_byte_data(client, PMBUS_STATUS_BYTE);
+       if (ret < 0 || ret == 0xff) {
+               data->status_register = PMBUS_STATUS_WORD;
+               ret = i2c_smbus_read_word_data(client, PMBUS_STATUS_WORD);
+               if (ret < 0 || ret == 0xffff) {
+                       dev_err(dev, "PMBus status register not found\n");
+                       return -ENODEV;
+               }
+       }
+
+       pmbus_clear_faults(client);
+
+       if (info->identify) {
+               ret = (*info->identify)(client, info);
+               if (ret < 0) {
+                       dev_err(dev, "Chip identification failed\n");
+                       return ret;
+               }
+       }
+
+       if (info->pages <= 0 || info->pages > PMBUS_PAGES) {
+               dev_err(dev, "Bad number of PMBus pages: %d\n", info->pages);
+               return -ENODEV;
+       }
+
+       for (page = 0; page < info->pages; page++) {
+               ret = pmbus_identify_common(client, data, page);
+               if (ret < 0) {
+                       dev_err(dev, "Failed to identify chip capabilities\n");
+                       return ret;
+               }
+       }
+       return 0;
+}
+
+#if IS_ENABLED(CONFIG_REGULATOR)
+static int pmbus_regulator_is_enabled(struct regulator_dev *rdev)
+{
+       struct device *dev = rdev_get_dev(rdev);
+       struct i2c_client *client = to_i2c_client(dev->parent);
+       u8 page = rdev_get_id(rdev);
+       int ret;
+
+       ret = pmbus_read_byte_data(client, page, PMBUS_OPERATION);
+       if (ret < 0)
+               return ret;
+
+       return !!(ret & PB_OPERATION_CONTROL_ON);
+}
+
+static int _pmbus_regulator_on_off(struct regulator_dev *rdev, bool enable)
+{
+       struct device *dev = rdev_get_dev(rdev);
+       struct i2c_client *client = to_i2c_client(dev->parent);
+       u8 page = rdev_get_id(rdev);
+
+       return pmbus_update_byte_data(client, page, PMBUS_OPERATION,
+                                     PB_OPERATION_CONTROL_ON,
+                                     enable ? PB_OPERATION_CONTROL_ON : 0);
+}
+
+static int pmbus_regulator_enable(struct regulator_dev *rdev)
+{
+       return _pmbus_regulator_on_off(rdev, 1);
+}
+
+static int pmbus_regulator_disable(struct regulator_dev *rdev)
+{
+       return _pmbus_regulator_on_off(rdev, 0);
+}
+
+struct regulator_ops pmbus_regulator_ops = {
+       .enable = pmbus_regulator_enable,
+       .disable = pmbus_regulator_disable,
+       .is_enabled = pmbus_regulator_is_enabled,
+};
+EXPORT_SYMBOL_GPL(pmbus_regulator_ops);
+
+static int pmbus_regulator_register(struct pmbus_data *data)
+{
+       struct device *dev = data->dev;
+       const struct pmbus_driver_info *info = data->info;
+       const struct pmbus_platform_data *pdata = dev_get_platdata(dev);
+       struct regulator_dev *rdev;
+       int i;
+
+       for (i = 0; i < info->num_regulators; i++) {
+               struct regulator_config config = { };
+
+               config.dev = dev;
+               config.driver_data = data;
+
+               if (pdata && pdata->reg_init_data)
+                       config.init_data = &pdata->reg_init_data[i];
+
+               rdev = devm_regulator_register(dev, &info->reg_desc[i],
+                                              &config);
+               if (IS_ERR(rdev)) {
+                       dev_err(dev, "Failed to register %s regulator\n",
+                               info->reg_desc[i].name);
+                       return PTR_ERR(rdev);
+               }
+       }
+
+       return 0;
+}
+#else
+static int pmbus_regulator_register(struct pmbus_data *data)
+{
+       return 0;
+}
+#endif
+
+int pmbus_do_probe(struct i2c_client *client, const struct i2c_device_id *id,
+                  struct pmbus_driver_info *info)
+{
+       struct device *dev = &client->dev;
+       const struct pmbus_platform_data *pdata = dev_get_platdata(dev);
+       struct pmbus_data *data;
+       int ret;
+
+       if (!info)
+               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 = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       i2c_set_clientdata(client, data);
+       mutex_init(&data->update_lock);
+       data->dev = dev;
+
+       if (pdata)
+               data->flags = pdata->flags;
+       data->info = info;
+
+       ret = pmbus_init_common(client, data, info);
+       if (ret < 0)
+               return ret;
+
+       ret = pmbus_find_attributes(client, data);
+       if (ret)
+               goto out_kfree;
+
+       /*
+        * If there are no attributes, something is wrong.
+        * Bail out instead of trying to register nothing.
+        */
+       if (!data->num_attributes) {
+               dev_err(dev, "No attributes found\n");
+               ret = -ENODEV;
+               goto out_kfree;
+       }
+
+       data->groups[0] = &data->group;
+       data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
+                                                           data, data->groups);
+       if (IS_ERR(data->hwmon_dev)) {
+               ret = PTR_ERR(data->hwmon_dev);
+               dev_err(dev, "Failed to register hwmon device\n");
+               goto out_kfree;
+       }
+
+       ret = pmbus_regulator_register(data);
+       if (ret)
+               goto out_unregister;
+
+       return 0;
+
+out_unregister:
+       hwmon_device_unregister(data->hwmon_dev);
+out_kfree:
+       kfree(data->group.attrs);
+       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);
+       kfree(data->group.attrs);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(pmbus_do_remove);
+
+MODULE_AUTHOR("Guenter Roeck");
+MODULE_DESCRIPTION("PMBus core driver");
+MODULE_LICENSE("GPL");