/*
 * lm63.c - driver for the National Semiconductor LM63 temperature sensor
 *          with integrated fan control
 * Copyright (C) 2004-2008  Jean Delvare <jdelvare@suse.de>
 * Based on the lm90 driver.
 *
 * The LM63 is a sensor chip made by National Semiconductor. It measures
 * two temperatures (its own and one external one) and the speed of one
 * fan, those speed it can additionally control. Complete datasheet can be
 * obtained from National's website at:
 *   http://www.national.com/pf/LM/LM63.html
 *
 * The LM63 is basically an LM86 with fan speed monitoring and control
 * capabilities added. It misses some of the LM86 features though:
 *  - No low limit for local temperature.
 *  - No critical limit for local temperature.
 *  - Critical limit for remote temperature can be changed only once. We
 *    will consider that the critical limit is read-only.
 *
 * The datasheet isn't very clear about what the tachometer reading is.
 * I had a explanation from National Semiconductor though. The two lower
 * bits of the read value have to be masked out. The value is still 16 bit
 * in width.
 *
 * 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/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon-sysfs.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/types.h>

/*
 * Addresses to scan
 * Address is fully defined internally and cannot be changed except for
 * LM64 which has one pin dedicated to address selection.
 * LM63 and LM96163 have address 0x4c.
 * LM64 can have address 0x18 or 0x4e.
 */

static const unsigned short normal_i2c[] = { 0x18, 0x4c, 0x4e, I2C_CLIENT_END };

/*
 * The LM63 registers
 */

#define LM63_REG_CONFIG1                0x03
#define LM63_REG_CONVRATE               0x04
#define LM63_REG_CONFIG2                0xBF
#define LM63_REG_CONFIG_FAN             0x4A

#define LM63_REG_TACH_COUNT_MSB         0x47
#define LM63_REG_TACH_COUNT_LSB         0x46
#define LM63_REG_TACH_LIMIT_MSB         0x49
#define LM63_REG_TACH_LIMIT_LSB         0x48

#define LM63_REG_PWM_VALUE              0x4C
#define LM63_REG_PWM_FREQ               0x4D
#define LM63_REG_LUT_TEMP_HYST          0x4F
#define LM63_REG_LUT_TEMP(nr)           (0x50 + 2 * (nr))
#define LM63_REG_LUT_PWM(nr)            (0x51 + 2 * (nr))

#define LM63_REG_LOCAL_TEMP             0x00
#define LM63_REG_LOCAL_HIGH             0x05

#define LM63_REG_REMOTE_TEMP_MSB        0x01
#define LM63_REG_REMOTE_TEMP_LSB        0x10
#define LM63_REG_REMOTE_OFFSET_MSB      0x11
#define LM63_REG_REMOTE_OFFSET_LSB      0x12
#define LM63_REG_REMOTE_HIGH_MSB        0x07
#define LM63_REG_REMOTE_HIGH_LSB        0x13
#define LM63_REG_REMOTE_LOW_MSB         0x08
#define LM63_REG_REMOTE_LOW_LSB         0x14
#define LM63_REG_REMOTE_TCRIT           0x19
#define LM63_REG_REMOTE_TCRIT_HYST      0x21

#define LM63_REG_ALERT_STATUS           0x02
#define LM63_REG_ALERT_MASK             0x16

#define LM63_REG_MAN_ID                 0xFE
#define LM63_REG_CHIP_ID                0xFF

#define LM96163_REG_TRUTHERM            0x30
#define LM96163_REG_REMOTE_TEMP_U_MSB   0x31
#define LM96163_REG_REMOTE_TEMP_U_LSB   0x32
#define LM96163_REG_CONFIG_ENHANCED     0x45

#define LM63_MAX_CONVRATE               9

#define LM63_MAX_CONVRATE_HZ            32
#define LM96163_MAX_CONVRATE_HZ         26

/*
 * Conversions and various macros
 * For tachometer counts, the LM63 uses 16-bit values.
 * For local temperature and high limit, remote critical limit and hysteresis
 * value, it uses signed 8-bit values with LSB = 1 degree Celsius.
 * For remote temperature, low and high limits, it uses signed 11-bit values
 * with LSB = 0.125 degree Celsius, left-justified in 16-bit registers.
 * For LM64 the actual remote diode temperature is 16 degree Celsius higher
 * than the register reading. Remote temperature setpoints have to be
 * adapted accordingly.
 */

#define FAN_FROM_REG(reg)       ((reg) == 0xFFFC || (reg) == 0 ? 0 : \
                                 5400000 / (reg))
#define FAN_TO_REG(val)         ((val) <= 82 ? 0xFFFC : \
                                 (5400000 / (val)) & 0xFFFC)
#define TEMP8_FROM_REG(reg)     ((reg) * 1000)
#define TEMP8_TO_REG(val)       ((val) <= -128000 ? -128 : \
                                 (val) >= 127000 ? 127 : \
                                 (val) < 0 ? ((val) - 500) / 1000 : \
                                 ((val) + 500) / 1000)
#define TEMP8U_TO_REG(val)      ((val) <= 0 ? 0 : \
                                 (val) >= 255000 ? 255 : \
                                 ((val) + 500) / 1000)
#define TEMP11_FROM_REG(reg)    ((reg) / 32 * 125)
#define TEMP11_TO_REG(val)      ((val) <= -128000 ? 0x8000 : \
                                 (val) >= 127875 ? 0x7FE0 : \
                                 (val) < 0 ? ((val) - 62) / 125 * 32 : \
                                 ((val) + 62) / 125 * 32)
#define TEMP11U_TO_REG(val)     ((val) <= 0 ? 0 : \
                                 (val) >= 255875 ? 0xFFE0 : \
                                 ((val) + 62) / 125 * 32)
#define HYST_TO_REG(val)        ((val) <= 0 ? 0 : \
                                 (val) >= 127000 ? 127 : \
                                 ((val) + 500) / 1000)

#define UPDATE_INTERVAL(max, rate) \
                        ((1000 << (LM63_MAX_CONVRATE - (rate))) / (max))

enum chips { lm63, lm64, lm96163 };

/*
 * Client data (each client gets its own)
 */

struct lm63_data {
        struct i2c_client *client;
        struct mutex update_lock;
        const struct attribute_group *groups[5];
        char valid; /* zero until following fields are valid */
        char lut_valid; /* zero until lut fields are valid */
        unsigned long last_updated; /* in jiffies */
        unsigned long lut_last_updated; /* in jiffies */
        enum chips kind;
        int temp2_offset;

        int update_interval;    /* in milliseconds */
        int max_convrate_hz;
        int lut_size;           /* 8 or 12 */

        /* registers values */
        u8 config, config_fan;
        u16 fan[2];     /* 0: input
                           1: low limit */
        u8 pwm1_freq;
        u8 pwm1[13];    /* 0: current output
                           1-12: lookup table */
        s8 temp8[15];   /* 0: local input
                           1: local high limit
                           2: remote critical limit
                           3-14: lookup table */
        s16 temp11[4];  /* 0: remote input
                           1: remote low limit
                           2: remote high limit
                           3: remote offset */
        u16 temp11u;    /* remote input (unsigned) */
        u8 temp2_crit_hyst;
        u8 lut_temp_hyst;
        u8 alarms;
        bool pwm_highres;
        bool lut_temp_highres;
        bool remote_unsigned; /* true if unsigned remote upper limits */
        bool trutherm;
};

static inline int temp8_from_reg(struct lm63_data *data, int nr)
{
        if (data->remote_unsigned)
                return TEMP8_FROM_REG((u8)data->temp8[nr]);
        return TEMP8_FROM_REG(data->temp8[nr]);
}

static inline int lut_temp_from_reg(struct lm63_data *data, int nr)
{
        return data->temp8[nr] * (data->lut_temp_highres ? 500 : 1000);
}

static inline int lut_temp_to_reg(struct lm63_data *data, long val)
{
        val -= data->temp2_offset;
        if (data->lut_temp_highres)
                return DIV_ROUND_CLOSEST(clamp_val(val, 0, 127500), 500);
        else
                return DIV_ROUND_CLOSEST(clamp_val(val, 0, 127000), 1000);
}

/*
 * Update the lookup table register cache.
 * client->update_lock must be held when calling this function.
 */
static void lm63_update_lut(struct lm63_data *data)
{
        struct i2c_client *client = data->client;
        int i;

        if (time_after(jiffies, data->lut_last_updated + 5 * HZ) ||
            !data->lut_valid) {
                for (i = 0; i < data->lut_size; i++) {
                        data->pwm1[1 + i] = i2c_smbus_read_byte_data(client,
                                            LM63_REG_LUT_PWM(i));
                        data->temp8[3 + i] = i2c_smbus_read_byte_data(client,
                                             LM63_REG_LUT_TEMP(i));
                }
                data->lut_temp_hyst = i2c_smbus_read_byte_data(client,
                                      LM63_REG_LUT_TEMP_HYST);

                data->lut_last_updated = jiffies;
                data->lut_valid = 1;
        }
}

static struct lm63_data *lm63_update_device(struct device *dev)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        unsigned long next_update;

        mutex_lock(&data->update_lock);

        next_update = data->last_updated +
                      msecs_to_jiffies(data->update_interval);
        if (time_after(jiffies, next_update) || !data->valid) {
                if (data->config & 0x04) { /* tachometer enabled  */
                        /* order matters for fan1_input */
                        data->fan[0] = i2c_smbus_read_byte_data(client,
                                       LM63_REG_TACH_COUNT_LSB) & 0xFC;
                        data->fan[0] |= i2c_smbus_read_byte_data(client,
                                        LM63_REG_TACH_COUNT_MSB) << 8;
                        data->fan[1] = (i2c_smbus_read_byte_data(client,
                                        LM63_REG_TACH_LIMIT_LSB) & 0xFC)
                                     | (i2c_smbus_read_byte_data(client,
                                        LM63_REG_TACH_LIMIT_MSB) << 8);
                }

                data->pwm1_freq = i2c_smbus_read_byte_data(client,
                                  LM63_REG_PWM_FREQ);
                if (data->pwm1_freq == 0)
                        data->pwm1_freq = 1;
                data->pwm1[0] = i2c_smbus_read_byte_data(client,
                                LM63_REG_PWM_VALUE);

                data->temp8[0] = i2c_smbus_read_byte_data(client,
                                 LM63_REG_LOCAL_TEMP);
                data->temp8[1] = i2c_smbus_read_byte_data(client,
                                 LM63_REG_LOCAL_HIGH);

                /* order matters for temp2_input */
                data->temp11[0] = i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_TEMP_MSB) << 8;
                data->temp11[0] |= i2c_smbus_read_byte_data(client,
                                   LM63_REG_REMOTE_TEMP_LSB);
                data->temp11[1] = (i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_LOW_MSB) << 8)
                                | i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_LOW_LSB);
                data->temp11[2] = (i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_HIGH_MSB) << 8)
                                | i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_HIGH_LSB);
                data->temp11[3] = (i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_OFFSET_MSB) << 8)
                                | i2c_smbus_read_byte_data(client,
                                  LM63_REG_REMOTE_OFFSET_LSB);

                if (data->kind == lm96163)
                        data->temp11u = (i2c_smbus_read_byte_data(client,
                                        LM96163_REG_REMOTE_TEMP_U_MSB) << 8)
                                      | i2c_smbus_read_byte_data(client,
                                        LM96163_REG_REMOTE_TEMP_U_LSB);

                data->temp8[2] = i2c_smbus_read_byte_data(client,
                                 LM63_REG_REMOTE_TCRIT);
                data->temp2_crit_hyst = i2c_smbus_read_byte_data(client,
                                        LM63_REG_REMOTE_TCRIT_HYST);

                data->alarms = i2c_smbus_read_byte_data(client,
                               LM63_REG_ALERT_STATUS) & 0x7F;

                data->last_updated = jiffies;
                data->valid = 1;
        }

        lm63_update_lut(data);

        mutex_unlock(&data->update_lock);

        return data;
}

/*
 * Trip points in the lookup table should be in ascending order for both
 * temperatures and PWM output values.
 */
static int lm63_lut_looks_bad(struct device *dev, struct lm63_data *data)
{
        int i;

        mutex_lock(&data->update_lock);
        lm63_update_lut(data);

        for (i = 1; i < data->lut_size; i++) {
                if (data->pwm1[1 + i - 1] > data->pwm1[1 + i]
                 || data->temp8[3 + i - 1] > data->temp8[3 + i]) {
                        dev_warn(dev,
                                 "Lookup table doesn't look sane (check entries %d and %d)\n",
                                 i, i + 1);
                        break;
                }
        }
        mutex_unlock(&data->update_lock);

        return i == data->lut_size ? 0 : 1;
}

/*
 * Sysfs callback functions and files
 */

static ssize_t show_fan(struct device *dev, struct device_attribute *devattr,
                        char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index]));
}

static ssize_t set_fan(struct device *dev, struct device_attribute *dummy,
                       const char *buf, size_t count)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        data->fan[1] = FAN_TO_REG(val);
        i2c_smbus_write_byte_data(client, LM63_REG_TACH_LIMIT_LSB,
                                  data->fan[1] & 0xFF);
        i2c_smbus_write_byte_data(client, LM63_REG_TACH_LIMIT_MSB,
                                  data->fan[1] >> 8);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_pwm1(struct device *dev, struct device_attribute *devattr,
                         char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        int nr = attr->index;
        int pwm;

        if (data->pwm_highres)
                pwm = data->pwm1[nr];
        else
                pwm = data->pwm1[nr] >= 2 * data->pwm1_freq ?
                       255 : (data->pwm1[nr] * 255 + data->pwm1_freq) /
                       (2 * data->pwm1_freq);

        return sprintf(buf, "%d\n", pwm);
}

static ssize_t set_pwm1(struct device *dev, struct device_attribute *devattr,
                        const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        int nr = attr->index;
        unsigned long val;
        int err;
        u8 reg;

        if (!(data->config_fan & 0x20)) /* register is read-only */
                return -EPERM;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        reg = nr ? LM63_REG_LUT_PWM(nr - 1) : LM63_REG_PWM_VALUE;
        val = clamp_val(val, 0, 255);

        mutex_lock(&data->update_lock);
        data->pwm1[nr] = data->pwm_highres ? val :
                        (val * data->pwm1_freq * 2 + 127) / 255;
        i2c_smbus_write_byte_data(client, reg, data->pwm1[nr]);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_pwm1_enable(struct device *dev,
                                struct device_attribute *dummy, char *buf)
{
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", data->config_fan & 0x20 ? 1 : 2);
}

static ssize_t set_pwm1_enable(struct device *dev,
                               struct device_attribute *dummy,
                               const char *buf, size_t count)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;
        if (val < 1 || val > 2)
                return -EINVAL;

        /*
         * Only let the user switch to automatic mode if the lookup table
         * looks sane.
         */
        if (val == 2 && lm63_lut_looks_bad(dev, data))
                return -EPERM;

        mutex_lock(&data->update_lock);
        data->config_fan = i2c_smbus_read_byte_data(client,
                                                    LM63_REG_CONFIG_FAN);
        if (val == 1)
                data->config_fan |= 0x20;
        else
                data->config_fan &= ~0x20;
        i2c_smbus_write_byte_data(client, LM63_REG_CONFIG_FAN,
                                  data->config_fan);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * There are 8bit registers for both local(temp1) and remote(temp2) sensor.
 * For remote sensor registers temp2_offset has to be considered,
 * for local sensor it must not.
 * So we need separate 8bit accessors for local and remote sensor.
 */
static ssize_t show_local_temp8(struct device *dev,
                                struct device_attribute *devattr,
                                char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", TEMP8_FROM_REG(data->temp8[attr->index]));
}

static ssize_t show_remote_temp8(struct device *dev,
                                 struct device_attribute *devattr,
                                 char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", temp8_from_reg(data, attr->index)
                       + data->temp2_offset);
}

static ssize_t show_lut_temp(struct device *dev,
                              struct device_attribute *devattr,
                              char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", lut_temp_from_reg(data, attr->index)
                       + data->temp2_offset);
}

static ssize_t set_temp8(struct device *dev, struct device_attribute *devattr,
                         const char *buf, size_t count)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        int nr = attr->index;
        long val;
        int err;
        int temp;
        u8 reg;

        err = kstrtol(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        switch (nr) {
        case 2:
                reg = LM63_REG_REMOTE_TCRIT;
                if (data->remote_unsigned)
                        temp = TEMP8U_TO_REG(val - data->temp2_offset);
                else
                        temp = TEMP8_TO_REG(val - data->temp2_offset);
                break;
        case 1:
                reg = LM63_REG_LOCAL_HIGH;
                temp = TEMP8_TO_REG(val);
                break;
        default:        /* lookup table */
                reg = LM63_REG_LUT_TEMP(nr - 3);
                temp = lut_temp_to_reg(data, val);
        }
        data->temp8[nr] = temp;
        i2c_smbus_write_byte_data(client, reg, temp);
        mutex_unlock(&data->update_lock);
        return count;
}

static ssize_t show_temp11(struct device *dev, struct device_attribute *devattr,
                           char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        int nr = attr->index;
        int temp;

        if (!nr) {
                /*
                 * Use unsigned temperature unless its value is zero.
                 * If it is zero, use signed temperature.
                 */
                if (data->temp11u)
                        temp = TEMP11_FROM_REG(data->temp11u);
                else
                        temp = TEMP11_FROM_REG(data->temp11[nr]);
        } else {
                if (data->remote_unsigned && nr == 2)
                        temp = TEMP11_FROM_REG((u16)data->temp11[nr]);
                else
                        temp = TEMP11_FROM_REG(data->temp11[nr]);
        }
        return sprintf(buf, "%d\n", temp + data->temp2_offset);
}

static ssize_t set_temp11(struct device *dev, struct device_attribute *devattr,
                          const char *buf, size_t count)
{
        static const u8 reg[6] = {
                LM63_REG_REMOTE_LOW_MSB,
                LM63_REG_REMOTE_LOW_LSB,
                LM63_REG_REMOTE_HIGH_MSB,
                LM63_REG_REMOTE_HIGH_LSB,
                LM63_REG_REMOTE_OFFSET_MSB,
                LM63_REG_REMOTE_OFFSET_LSB,
        };

        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        long val;
        int err;
        int nr = attr->index;

        err = kstrtol(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        if (data->remote_unsigned && nr == 2)
                data->temp11[nr] = TEMP11U_TO_REG(val - data->temp2_offset);
        else
                data->temp11[nr] = TEMP11_TO_REG(val - data->temp2_offset);

        i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2],
                                  data->temp11[nr] >> 8);
        i2c_smbus_write_byte_data(client, reg[(nr - 1) * 2 + 1],
                                  data->temp11[nr] & 0xff);
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * Hysteresis register holds a relative value, while we want to present
 * an absolute to user-space
 */
static ssize_t show_temp2_crit_hyst(struct device *dev,
                                    struct device_attribute *dummy, char *buf)
{
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%d\n", temp8_from_reg(data, 2)
                       + data->temp2_offset
                       - TEMP8_FROM_REG(data->temp2_crit_hyst));
}

static ssize_t show_lut_temp_hyst(struct device *dev,
                                  struct device_attribute *devattr, char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);

        return sprintf(buf, "%d\n", lut_temp_from_reg(data, attr->index)
                       + data->temp2_offset
                       - TEMP8_FROM_REG(data->lut_temp_hyst));
}

/*
 * And now the other way around, user-space provides an absolute
 * hysteresis value and we have to store a relative one
 */
static ssize_t set_temp2_crit_hyst(struct device *dev,
                                   struct device_attribute *dummy,
                                   const char *buf, size_t count)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        long val;
        int err;
        long hyst;

        err = kstrtol(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        hyst = temp8_from_reg(data, 2) + data->temp2_offset - val;
        i2c_smbus_write_byte_data(client, LM63_REG_REMOTE_TCRIT_HYST,
                                  HYST_TO_REG(hyst));
        mutex_unlock(&data->update_lock);
        return count;
}

/*
 * Set conversion rate.
 * client->update_lock must be held when calling this function.
 */
static void lm63_set_convrate(struct lm63_data *data, unsigned int interval)
{
        struct i2c_client *client = data->client;
        unsigned int update_interval;
        int i;

        /* Shift calculations to avoid rounding errors */
        interval <<= 6;

        /* find the nearest update rate */
        update_interval = (1 << (LM63_MAX_CONVRATE + 6)) * 1000
          / data->max_convrate_hz;
        for (i = 0; i < LM63_MAX_CONVRATE; i++, update_interval >>= 1)
                if (interval >= update_interval * 3 / 4)
                        break;

        i2c_smbus_write_byte_data(client, LM63_REG_CONVRATE, i);
        data->update_interval = UPDATE_INTERVAL(data->max_convrate_hz, i);
}

static ssize_t show_update_interval(struct device *dev,
                                    struct device_attribute *attr, char *buf)
{
        struct lm63_data *data = dev_get_drvdata(dev);

        return sprintf(buf, "%u\n", data->update_interval);
}

static ssize_t set_update_interval(struct device *dev,
                                   struct device_attribute *attr,
                                   const char *buf, size_t count)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        unsigned long val;
        int err;

        err = kstrtoul(buf, 10, &val);
        if (err)
                return err;

        mutex_lock(&data->update_lock);
        lm63_set_convrate(data, clamp_val(val, 0, 100000));
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t show_type(struct device *dev, struct device_attribute *attr,
                         char *buf)
{
        struct lm63_data *data = dev_get_drvdata(dev);

        return sprintf(buf, data->trutherm ? "1\n" : "2\n");
}

static ssize_t set_type(struct device *dev, struct device_attribute *attr,
                        const char *buf, size_t count)
{
        struct lm63_data *data = dev_get_drvdata(dev);
        struct i2c_client *client = data->client;
        unsigned long val;
        int ret;
        u8 reg;

        ret = kstrtoul(buf, 10, &val);
        if (ret < 0)
                return ret;
        if (val != 1 && val != 2)
                return -EINVAL;

        mutex_lock(&data->update_lock);
        data->trutherm = val == 1;
        reg = i2c_smbus_read_byte_data(client, LM96163_REG_TRUTHERM) & ~0x02;
        i2c_smbus_write_byte_data(client, LM96163_REG_TRUTHERM,
                                  reg | (data->trutherm ? 0x02 : 0x00));
        data->valid = 0;
        mutex_unlock(&data->update_lock);

        return count;
}

static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
                           char *buf)
{
        struct lm63_data *data = lm63_update_device(dev);
        return sprintf(buf, "%u\n", data->alarms);
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *devattr,
                          char *buf)
{
        struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
        struct lm63_data *data = lm63_update_device(dev);
        int bitnr = attr->index;

        return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
}

static SENSOR_DEVICE_ATTR(fan1_input, S_IRUGO, show_fan, NULL, 0);
static SENSOR_DEVICE_ATTR(fan1_min, S_IWUSR | S_IRUGO, show_fan,
        set_fan, 1);

static SENSOR_DEVICE_ATTR(pwm1, S_IWUSR | S_IRUGO, show_pwm1, set_pwm1, 0);
static DEVICE_ATTR(pwm1_enable, S_IWUSR | S_IRUGO,
        show_pwm1_enable, set_pwm1_enable);
static SENSOR_DEVICE_ATTR(pwm1_auto_point1_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 1);
static SENSOR_DEVICE_ATTR(pwm1_auto_point1_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 3);
static SENSOR_DEVICE_ATTR(pwm1_auto_point1_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 3);
static SENSOR_DEVICE_ATTR(pwm1_auto_point2_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 2);
static SENSOR_DEVICE_ATTR(pwm1_auto_point2_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 4);
static SENSOR_DEVICE_ATTR(pwm1_auto_point2_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 4);
static SENSOR_DEVICE_ATTR(pwm1_auto_point3_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 3);
static SENSOR_DEVICE_ATTR(pwm1_auto_point3_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 5);
static SENSOR_DEVICE_ATTR(pwm1_auto_point3_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 5);
static SENSOR_DEVICE_ATTR(pwm1_auto_point4_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 4);
static SENSOR_DEVICE_ATTR(pwm1_auto_point4_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 6);
static SENSOR_DEVICE_ATTR(pwm1_auto_point4_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 6);
static SENSOR_DEVICE_ATTR(pwm1_auto_point5_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 5);
static SENSOR_DEVICE_ATTR(pwm1_auto_point5_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 7);
static SENSOR_DEVICE_ATTR(pwm1_auto_point5_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 7);
static SENSOR_DEVICE_ATTR(pwm1_auto_point6_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 6);
static SENSOR_DEVICE_ATTR(pwm1_auto_point6_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 8);
static SENSOR_DEVICE_ATTR(pwm1_auto_point6_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 8);
static SENSOR_DEVICE_ATTR(pwm1_auto_point7_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 7);
static SENSOR_DEVICE_ATTR(pwm1_auto_point7_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 9);
static SENSOR_DEVICE_ATTR(pwm1_auto_point7_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 9);
static SENSOR_DEVICE_ATTR(pwm1_auto_point8_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 8);
static SENSOR_DEVICE_ATTR(pwm1_auto_point8_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 10);
static SENSOR_DEVICE_ATTR(pwm1_auto_point8_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 10);
static SENSOR_DEVICE_ATTR(pwm1_auto_point9_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 9);
static SENSOR_DEVICE_ATTR(pwm1_auto_point9_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 11);
static SENSOR_DEVICE_ATTR(pwm1_auto_point9_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 11);
static SENSOR_DEVICE_ATTR(pwm1_auto_point10_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 10);
static SENSOR_DEVICE_ATTR(pwm1_auto_point10_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 12);
static SENSOR_DEVICE_ATTR(pwm1_auto_point10_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 12);
static SENSOR_DEVICE_ATTR(pwm1_auto_point11_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 11);
static SENSOR_DEVICE_ATTR(pwm1_auto_point11_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 13);
static SENSOR_DEVICE_ATTR(pwm1_auto_point11_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 13);
static SENSOR_DEVICE_ATTR(pwm1_auto_point12_pwm, S_IWUSR | S_IRUGO,
        show_pwm1, set_pwm1, 12);
static SENSOR_DEVICE_ATTR(pwm1_auto_point12_temp, S_IWUSR | S_IRUGO,
        show_lut_temp, set_temp8, 14);
static SENSOR_DEVICE_ATTR(pwm1_auto_point12_temp_hyst, S_IRUGO,
        show_lut_temp_hyst, NULL, 14);

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_local_temp8, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_local_temp8,
        set_temp8, 1);

static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp11, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_temp11,
        set_temp11, 1);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp11,
        set_temp11, 2);
static SENSOR_DEVICE_ATTR(temp2_offset, S_IWUSR | S_IRUGO, show_temp11,
        set_temp11, 3);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_remote_temp8,
        set_temp8, 2);
static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp2_crit_hyst,
        set_temp2_crit_hyst);

static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type);

/* Individual alarm files */
static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 2);
static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 3);
static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
/* Raw alarm file for compatibility */
static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);

static DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR, show_update_interval,
                   set_update_interval);

static struct attribute *lm63_attributes[] = {
        &sensor_dev_attr_pwm1.dev_attr.attr,
        &dev_attr_pwm1_enable.attr,
        &sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point1_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point1_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point2_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point2_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point3_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point3_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point3_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point4_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point4_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point4_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point5_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point5_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point5_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point6_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point6_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point6_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point7_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point7_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point7_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point8_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point8_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point8_temp_hyst.dev_attr.attr,

        &sensor_dev_attr_temp1_input.dev_attr.attr,
        &sensor_dev_attr_temp2_input.dev_attr.attr,
        &sensor_dev_attr_temp2_min.dev_attr.attr,
        &sensor_dev_attr_temp1_max.dev_attr.attr,
        &sensor_dev_attr_temp2_max.dev_attr.attr,
        &sensor_dev_attr_temp2_offset.dev_attr.attr,
        &sensor_dev_attr_temp2_crit.dev_attr.attr,
        &dev_attr_temp2_crit_hyst.attr,

        &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
        &sensor_dev_attr_temp2_fault.dev_attr.attr,
        &sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
        &sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
        &dev_attr_alarms.attr,
        &dev_attr_update_interval.attr,
        NULL
};

static struct attribute *lm63_attributes_temp2_type[] = {
        &dev_attr_temp2_type.attr,
        NULL
};

static const struct attribute_group lm63_group_temp2_type = {
        .attrs = lm63_attributes_temp2_type,
};

static struct attribute *lm63_attributes_extra_lut[] = {
        &sensor_dev_attr_pwm1_auto_point9_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point9_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point9_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point10_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point10_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point10_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point11_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point11_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point11_temp_hyst.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point12_pwm.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point12_temp.dev_attr.attr,
        &sensor_dev_attr_pwm1_auto_point12_temp_hyst.dev_attr.attr,
        NULL
};

static const struct attribute_group lm63_group_extra_lut = {
        .attrs = lm63_attributes_extra_lut,
};

/*
 * On LM63, temp2_crit can be set only once, which should be job
 * of the bootloader.
 * On LM64, temp2_crit can always be set.
 * On LM96163, temp2_crit can be set if bit 1 of the configuration
 * register is true.
 */
static umode_t lm63_attribute_mode(struct kobject *kobj,
                                   struct attribute *attr, int index)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct lm63_data *data = dev_get_drvdata(dev);

        if (attr == &sensor_dev_attr_temp2_crit.dev_attr.attr
            && (data->kind == lm64 ||
                (data->kind == lm96163 && (data->config & 0x02))))
                return attr->mode | S_IWUSR;

        return attr->mode;
}

static const struct attribute_group lm63_group = {
        .is_visible = lm63_attribute_mode,
        .attrs = lm63_attributes,
};

static struct attribute *lm63_attributes_fan1[] = {
        &sensor_dev_attr_fan1_input.dev_attr.attr,
        &sensor_dev_attr_fan1_min.dev_attr.attr,

        &sensor_dev_attr_fan1_min_alarm.dev_attr.attr,
        NULL
};

static const struct attribute_group lm63_group_fan1 = {
        .attrs = lm63_attributes_fan1,
};

/*
 * Real code
 */

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm63_detect(struct i2c_client *client,
                       struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = client->adapter;
        u8 man_id, chip_id, reg_config1, reg_config2;
        u8 reg_alert_status, reg_alert_mask;
        int address = client->addr;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
                return -ENODEV;

        man_id = i2c_smbus_read_byte_data(client, LM63_REG_MAN_ID);
        chip_id = i2c_smbus_read_byte_data(client, LM63_REG_CHIP_ID);

        reg_config1 = i2c_smbus_read_byte_data(client, LM63_REG_CONFIG1);
        reg_config2 = i2c_smbus_read_byte_data(client, LM63_REG_CONFIG2);
        reg_alert_status = i2c_smbus_read_byte_data(client,
                           LM63_REG_ALERT_STATUS);
        reg_alert_mask = i2c_smbus_read_byte_data(client, LM63_REG_ALERT_MASK);

        if (man_id != 0x01 /* National Semiconductor */
         || (reg_config1 & 0x18) != 0x00
         || (reg_config2 & 0xF8) != 0x00
         || (reg_alert_status & 0x20) != 0x00
         || (reg_alert_mask & 0xA4) != 0xA4) {
                dev_dbg(&adapter->dev,
                        "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
                        man_id, chip_id);
                return -ENODEV;
        }

        if (chip_id == 0x41 && address == 0x4c)
                strlcpy(info->type, "lm63", I2C_NAME_SIZE);
        else if (chip_id == 0x51 && (address == 0x18 || address == 0x4e))
                strlcpy(info->type, "lm64", I2C_NAME_SIZE);
        else if (chip_id == 0x49 && address == 0x4c)
                strlcpy(info->type, "lm96163", I2C_NAME_SIZE);
        else
                return -ENODEV;

        return 0;
}

/*
 * Ideally we shouldn't have to initialize anything, since the BIOS
 * should have taken care of everything
 */
static void lm63_init_client(struct lm63_data *data)
{
        struct i2c_client *client = data->client;
        struct device *dev = &client->dev;
        u8 convrate;

        data->config = i2c_smbus_read_byte_data(client, LM63_REG_CONFIG1);
        data->config_fan = i2c_smbus_read_byte_data(client,
                                                    LM63_REG_CONFIG_FAN);

        /* Start converting if needed */
        if (data->config & 0x40) { /* standby */
                dev_dbg(dev, "Switching to operational mode\n");
                data->config &= 0xA7;
                i2c_smbus_write_byte_data(client, LM63_REG_CONFIG1,
                                          data->config);
        }
        /* Tachometer is always enabled on LM64 */
        if (data->kind == lm64)
                data->config |= 0x04;

        /* We may need pwm1_freq before ever updating the client data */
        data->pwm1_freq = i2c_smbus_read_byte_data(client, LM63_REG_PWM_FREQ);
        if (data->pwm1_freq == 0)
                data->pwm1_freq = 1;

        switch (data->kind) {
        case lm63:
        case lm64:
                data->max_convrate_hz = LM63_MAX_CONVRATE_HZ;
                data->lut_size = 8;
                break;
        case lm96163:
                data->max_convrate_hz = LM96163_MAX_CONVRATE_HZ;
                data->lut_size = 12;
                data->trutherm
                  = i2c_smbus_read_byte_data(client,
                                             LM96163_REG_TRUTHERM) & 0x02;
                break;
        }
        convrate = i2c_smbus_read_byte_data(client, LM63_REG_CONVRATE);
        if (unlikely(convrate > LM63_MAX_CONVRATE))
                convrate = LM63_MAX_CONVRATE;
        data->update_interval = UPDATE_INTERVAL(data->max_convrate_hz,
                                                convrate);

        /*
         * For LM96163, check if high resolution PWM
         * and unsigned temperature format is enabled.
         */
        if (data->kind == lm96163) {
                u8 config_enhanced
                  = i2c_smbus_read_byte_data(client,
                                             LM96163_REG_CONFIG_ENHANCED);
                if (config_enhanced & 0x20)
                        data->lut_temp_highres = true;
                if ((config_enhanced & 0x10)
                    && !(data->config_fan & 0x08) && data->pwm1_freq == 8)
                        data->pwm_highres = true;
                if (config_enhanced & 0x08)
                        data->remote_unsigned = true;
        }

        /* Show some debug info about the LM63 configuration */
        if (data->kind == lm63)
                dev_dbg(dev, "Alert/tach pin configured for %s\n",
                        (data->config & 0x04) ? "tachometer input" :
                        "alert output");
        dev_dbg(dev, "PWM clock %s kHz, output frequency %u Hz\n",
                (data->config_fan & 0x08) ? "1.4" : "360",
                ((data->config_fan & 0x08) ? 700 : 180000) / data->pwm1_freq);
        dev_dbg(dev, "PWM output active %s, %s mode\n",
                (data->config_fan & 0x10) ? "low" : "high",
                (data->config_fan & 0x20) ? "manual" : "auto");
}

static int lm63_probe(struct i2c_client *client,
                      const struct i2c_device_id *id)
{
        struct device *dev = &client->dev;
        struct device *hwmon_dev;
        struct lm63_data *data;
        int groups = 0;

        data = devm_kzalloc(dev, sizeof(struct lm63_data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        data->client = client;
        mutex_init(&data->update_lock);

        /* Set the device type */
        data->kind = id->driver_data;
        if (data->kind == lm64)
                data->temp2_offset = 16000;

        /* Initialize chip */
        lm63_init_client(data);

        /* Register sysfs hooks */
        data->groups[groups++] = &lm63_group;
        if (data->config & 0x04)        /* tachometer enabled */
                data->groups[groups++] = &lm63_group_fan1;

        if (data->kind == lm96163) {
                data->groups[groups++] = &lm63_group_temp2_type;
                data->groups[groups++] = &lm63_group_extra_lut;
        }

        hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
                                                           data, data->groups);
        return PTR_ERR_OR_ZERO(hwmon_dev);
}

/*
 * Driver data (common to all clients)
 */

static const struct i2c_device_id lm63_id[] = {
        { "lm63", lm63 },
        { "lm64", lm64 },
        { "lm96163", lm96163 },
        { }
};
MODULE_DEVICE_TABLE(i2c, lm63_id);

static struct i2c_driver lm63_driver = {
        .class          = I2C_CLASS_HWMON,
        .driver = {
                .name   = "lm63",
        },
        .probe          = lm63_probe,
        .id_table       = lm63_id,
        .detect         = lm63_detect,
        .address_list   = normal_i2c,
};

module_i2c_driver(lm63_driver);

MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("LM63 driver");
MODULE_LICENSE("GPL");