procfs: do not confuse jiffies with cputime64_t

[zen-stable.git] / drivers / hwmon / jc42.c

/*
 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
 *
 * Copyright (c) 2010  Ericsson AB.
 *
 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
 *
 * JC42.4 compliant temperature sensors are typically used on memory modules.
 *
 * 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.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = {
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };

/* JC42 registers. All registers are 16 bit. */
#define JC42_REG_CAP            0x00
#define JC42_REG_CONFIG         0x01
#define JC42_REG_TEMP_UPPER     0x02
#define JC42_REG_TEMP_LOWER     0x03
#define JC42_REG_TEMP_CRITICAL  0x04
#define JC42_REG_TEMP           0x05
#define JC42_REG_MANID          0x06
#define JC42_REG_DEVICEID       0x07

/* Status bits in temperature register */
#define JC42_ALARM_CRIT_BIT     15
#define JC42_ALARM_MAX_BIT      14
#define JC42_ALARM_MIN_BIT      13

/* Configuration register defines */
#define JC42_CFG_CRIT_ONLY      (1 << 2)
#define JC42_CFG_TCRIT_LOCK     (1 << 6)
#define JC42_CFG_EVENT_LOCK     (1 << 7)
#define JC42_CFG_SHUTDOWN       (1 << 8)
#define JC42_CFG_HYST_SHIFT     9
#define JC42_CFG_HYST_MASK      0x03

/* Capabilities */
#define JC42_CAP_RANGE          (1 << 2)

/* Manufacturer IDs */
#define ADT_MANID               0x11d4  /* Analog Devices */
#define MAX_MANID               0x004d  /* Maxim */
#define IDT_MANID               0x00b3  /* IDT */
#define MCP_MANID               0x0054  /* Microchip */
#define NXP_MANID               0x1131  /* NXP Semiconductors */
#define ONS_MANID               0x1b09  /* ON Semiconductor */
#define STM_MANID               0x104a  /* ST Microelectronics */

/* Supported chips */

/* Analog Devices */
#define ADT7408_DEVID           0x0801
#define ADT7408_DEVID_MASK      0xffff

/* IDT */
#define TS3000B3_DEVID          0x2903  /* Also matches TSE2002B3 */
#define TS3000B3_DEVID_MASK     0xffff

/* Maxim */
#define MAX6604_DEVID           0x3e00
#define MAX6604_DEVID_MASK      0xffff

/* Microchip */
#define MCP98242_DEVID          0x2000
#define MCP98242_DEVID_MASK     0xfffc

#define MCP98243_DEVID          0x2100
#define MCP98243_DEVID_MASK     0xfffc

#define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
#define MCP9843_DEVID_MASK      0xfffe

/* NXP */
#define SE97_DEVID              0xa200
#define SE97_DEVID_MASK         0xfffc

#define SE98_DEVID              0xa100
#define SE98_DEVID_MASK         0xfffc

/* ON Semiconductor */
#define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
#define CAT6095_DEVID_MASK      0xffe0

/* ST Microelectronics */
#define STTS424_DEVID           0x0101
#define STTS424_DEVID_MASK      0xffff

#define STTS424E_DEVID          0x0000
#define STTS424E_DEVID_MASK     0xfffe

static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };

struct jc42_chips {
        u16 manid;
        u16 devid;
        u16 devid_mask;
};

static struct jc42_chips jc42_chips[] = {
        { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
        { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
        { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
        { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
        { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
        { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
        { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
        { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
        { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
        { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
        { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
};

/* Each client has this additional data */
struct jc42_data {
        struct device   *hwmon_dev;
        struct mutex    update_lock;    /* protect register access */
        bool            extended;       /* true if extended range supported */
        bool            valid;
        unsigned long   last_updated;   /* In jiffies */
        u16             orig_config;    /* original configuration */
        u16             config;         /* current configuration */
        u16             temp_input;     /* Temperatures */
        u16             temp_crit;
        u16             temp_min;
        u16             temp_max;
};

static int jc42_probe(struct i2c_client *client,
                      const struct i2c_device_id *id);
static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
static int jc42_remove(struct i2c_client *client);

static struct jc42_data *jc42_update_device(struct device *dev);

static const struct i2c_device_id jc42_id[] = {
        { "adt7408", 0 },
        { "cat94ts02", 0 },
        { "cat6095", 0 },
        { "jc42", 0 },
        { "max6604", 0 },
        { "mcp9805", 0 },
        { "mcp98242", 0 },
        { "mcp98243", 0 },
        { "mcp9843", 0 },
        { "se97", 0 },
        { "se97b", 0 },
        { "se98", 0 },
        { "stts424", 0 },
        { "tse2002b3", 0 },
        { "ts3000b3", 0 },
        { }
};
MODULE_DEVICE_TABLE(i2c, jc42_id);

#ifdef CONFIG_PM

static int jc42_suspend(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct jc42_data *data = i2c_get_clientdata(client);

        data->config |= JC42_CFG_SHUTDOWN;
        i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
        return 0;
}

static int jc42_resume(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct jc42_data *data = i2c_get_clientdata(client);

        data->config &= ~JC42_CFG_SHUTDOWN;
        i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
        return 0;
}

static const struct dev_pm_ops jc42_dev_pm_ops = {
        .suspend = jc42_suspend,
        .resume = jc42_resume,
};

#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
#else
#define JC42_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

/* This is the driver that will be inserted */
static struct i2c_driver jc42_driver = {
        .class          = I2C_CLASS_SPD,
        .driver = {
                .name   = "jc42",
                .pm = JC42_DEV_PM_OPS,
        },
        .probe          = jc42_probe,
        .remove         = jc42_remove,
        .id_table       = jc42_id,
        .detect         = jc42_detect,
        .address_list   = normal_i2c,
};

#define JC42_TEMP_MIN_EXTENDED  (-40000)
#define JC42_TEMP_MIN           0
#define JC42_TEMP_MAX           125000

static u16 jc42_temp_to_reg(int temp, bool extended)
{
        int ntemp = SENSORS_LIMIT(temp,
                                  extended ? JC42_TEMP_MIN_EXTENDED :
                                  JC42_TEMP_MIN, JC42_TEMP_MAX);

        /* convert from 0.001 to 0.0625 resolution */
        return (ntemp * 2 / 125) & 0x1fff;
}

static int jc42_temp_from_reg(s16 reg)
{
        reg &= 0x1fff;

        /* sign extend register */
        if (reg & 0x1000)
                reg |= 0xf000;

        /* convert from 0.0625 to 0.001 resolution */
        return reg * 125 / 2;
}

/* sysfs stuff */

/* read routines for temperature limits */
#define show(value)     \
static ssize_t show_##value(struct device *dev,                         \
                            struct device_attribute *attr,              \
                            char *buf)                                  \
{                                                                       \
        struct jc42_data *data = jc42_update_device(dev);               \
        if (IS_ERR(data))                                               \
                return PTR_ERR(data);                                   \
        return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));   \
}

show(temp_input);
show(temp_crit);
show(temp_min);
show(temp_max);

/* read routines for hysteresis values */
static ssize_t show_temp_crit_hyst(struct device *dev,
                                   struct device_attribute *attr, char *buf)
{
        struct jc42_data *data = jc42_update_device(dev);
        int temp, hyst;

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

        temp = jc42_temp_from_reg(data->temp_crit);
        hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
                               & JC42_CFG_HYST_MASK];
        return sprintf(buf, "%d\n", temp - hyst);
}

static ssize_t show_temp_max_hyst(struct device *dev,
                                  struct device_attribute *attr, char *buf)
{
        struct jc42_data *data = jc42_update_device(dev);
        int temp, hyst;

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

        temp = jc42_temp_from_reg(data->temp_max);
        hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
                               & JC42_CFG_HYST_MASK];
        return sprintf(buf, "%d\n", temp - hyst);
}

/* write routines */
#define set(value, reg) \
static ssize_t set_##value(struct device *dev,                          \
                           struct device_attribute *attr,               \
                           const char *buf, size_t count)               \
{                                                                       \
        struct i2c_client *client = to_i2c_client(dev);                 \
        struct jc42_data *data = i2c_get_clientdata(client);            \
        int err, ret = count;                                           \
        long val;                                                       \
        if (strict_strtol(buf, 10, &val) < 0)                           \
                return -EINVAL;                                         \
        mutex_lock(&data->update_lock);                                 \
        data->value = jc42_temp_to_reg(val, data->extended);            \
        err = i2c_smbus_write_word_swapped(client, reg, data->value);   \
        if (err < 0)                                                    \
                ret = err;                                              \
        mutex_unlock(&data->update_lock);                               \
        return ret;                                                     \
}

set(temp_min, JC42_REG_TEMP_LOWER);
set(temp_max, JC42_REG_TEMP_UPPER);
set(temp_crit, JC42_REG_TEMP_CRITICAL);

/* JC42.4 compliant chips only support four hysteresis values.
 * Pick best choice and go from there. */
static ssize_t set_temp_crit_hyst(struct device *dev,
                                  struct device_attribute *attr,
                                  const char *buf, size_t count)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct jc42_data *data = i2c_get_clientdata(client);
        unsigned long val;
        int diff, hyst;
        int err;
        int ret = count;

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

        diff = jc42_temp_from_reg(data->temp_crit) - val;
        hyst = 0;
        if (diff > 0) {
                if (diff < 2250)
                        hyst = 1;       /* 1.5 degrees C */
                else if (diff < 4500)
                        hyst = 2;       /* 3.0 degrees C */
                else
                        hyst = 3;       /* 6.0 degrees C */
        }

        mutex_lock(&data->update_lock);
        data->config = (data->config
                        & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
          | (hyst << JC42_CFG_HYST_SHIFT);
        err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
                                           data->config);
        if (err < 0)
                ret = err;
        mutex_unlock(&data->update_lock);
        return ret;
}

static ssize_t show_alarm(struct device *dev,
                          struct device_attribute *attr, char *buf)
{
        u16 bit = to_sensor_dev_attr(attr)->index;
        struct jc42_data *data = jc42_update_device(dev);
        u16 val;

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

        val = data->temp_input;
        if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
                val = 0;
        return sprintf(buf, "%u\n", (val >> bit) & 1);
}

static DEVICE_ATTR(temp1_input, S_IRUGO,
                   show_temp_input, NULL);
static DEVICE_ATTR(temp1_crit, S_IRUGO,
                   show_temp_crit, set_temp_crit);
static DEVICE_ATTR(temp1_min, S_IRUGO,
                   show_temp_min, set_temp_min);
static DEVICE_ATTR(temp1_max, S_IRUGO,
                   show_temp_max, set_temp_max);

static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
                   show_temp_crit_hyst, set_temp_crit_hyst);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
                   show_temp_max_hyst, NULL);

static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
                          JC42_ALARM_CRIT_BIT);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
                          JC42_ALARM_MIN_BIT);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
                          JC42_ALARM_MAX_BIT);

static struct attribute *jc42_attributes[] = {
        &dev_attr_temp1_input.attr,
        &dev_attr_temp1_crit.attr,
        &dev_attr_temp1_min.attr,
        &dev_attr_temp1_max.attr,
        &dev_attr_temp1_crit_hyst.attr,
        &dev_attr_temp1_max_hyst.attr,
        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
        NULL
};

static mode_t jc42_attribute_mode(struct kobject *kobj,
                                  struct attribute *attr, int index)
{
        struct device *dev = container_of(kobj, struct device, kobj);
        struct i2c_client *client = to_i2c_client(dev);
        struct jc42_data *data = i2c_get_clientdata(client);
        unsigned int config = data->config;
        bool readonly;

        if (attr == &dev_attr_temp1_crit.attr)
                readonly = config & JC42_CFG_TCRIT_LOCK;
        else if (attr == &dev_attr_temp1_min.attr ||
                 attr == &dev_attr_temp1_max.attr)
                readonly = config & JC42_CFG_EVENT_LOCK;
        else if (attr == &dev_attr_temp1_crit_hyst.attr)
                readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
        else
                readonly = true;

        return S_IRUGO | (readonly ? 0 : S_IWUSR);
}

static const struct attribute_group jc42_group = {
        .attrs = jc42_attributes,
        .is_visible = jc42_attribute_mode,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int jc42_detect(struct i2c_client *new_client,
                       struct i2c_board_info *info)
{
        struct i2c_adapter *adapter = new_client->adapter;
        int i, config, cap, manid, devid;

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

        cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
        config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
        manid = i2c_smbus_read_word_swapped(new_client, JC42_REG_MANID);
        devid = i2c_smbus_read_word_swapped(new_client, JC42_REG_DEVICEID);

        if (cap < 0 || config < 0 || manid < 0 || devid < 0)
                return -ENODEV;

        if ((cap & 0xff00) || (config & 0xf800))
                return -ENODEV;

        for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
                struct jc42_chips *chip = &jc42_chips[i];
                if (manid == chip->manid &&
                    (devid & chip->devid_mask) == chip->devid) {
                        strlcpy(info->type, "jc42", I2C_NAME_SIZE);
                        return 0;
                }
        }
        return -ENODEV;
}

static int jc42_probe(struct i2c_client *new_client,
                      const struct i2c_device_id *id)
{
        struct jc42_data *data;
        int config, cap, err;

        data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
        if (!data) {
                err = -ENOMEM;
                goto exit;
        }

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

        cap = i2c_smbus_read_word_swapped(new_client, JC42_REG_CAP);
        if (cap < 0) {
                err = -EINVAL;
                goto exit_free;
        }
        data->extended = !!(cap & JC42_CAP_RANGE);

        config = i2c_smbus_read_word_swapped(new_client, JC42_REG_CONFIG);
        if (config < 0) {
                err = -EINVAL;
                goto exit_free;
        }
        data->orig_config = config;
        if (config & JC42_CFG_SHUTDOWN) {
                config &= ~JC42_CFG_SHUTDOWN;
                i2c_smbus_write_word_swapped(new_client, JC42_REG_CONFIG,
                                             config);
        }
        data->config = config;

        /* Register sysfs hooks */
        err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
        if (err)
                goto exit_free;

        data->hwmon_dev = hwmon_device_register(&new_client->dev);
        if (IS_ERR(data->hwmon_dev)) {
                err = PTR_ERR(data->hwmon_dev);
                goto exit_remove;
        }

        return 0;

exit_remove:
        sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
exit_free:
        kfree(data);
exit:
        return err;
}

static int jc42_remove(struct i2c_client *client)
{
        struct jc42_data *data = i2c_get_clientdata(client);
        hwmon_device_unregister(data->hwmon_dev);
        sysfs_remove_group(&client->dev.kobj, &jc42_group);
        if (data->config != data->orig_config)
                i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
                                             data->orig_config);
        kfree(data);
        return 0;
}

static struct jc42_data *jc42_update_device(struct device *dev)
{
        struct i2c_client *client = to_i2c_client(dev);
        struct jc42_data *data = i2c_get_clientdata(client);
        struct jc42_data *ret = data;
        int val;

        mutex_lock(&data->update_lock);

        if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
                val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
                if (val < 0) {
                        ret = ERR_PTR(val);
                        goto abort;
                }
                data->temp_input = val;

                val = i2c_smbus_read_word_swapped(client,
                                                  JC42_REG_TEMP_CRITICAL);
                if (val < 0) {
                        ret = ERR_PTR(val);
                        goto abort;
                }
                data->temp_crit = val;

                val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
                if (val < 0) {
                        ret = ERR_PTR(val);
                        goto abort;
                }
                data->temp_min = val;

                val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
                if (val < 0) {
                        ret = ERR_PTR(val);
                        goto abort;
                }
                data->temp_max = val;

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

static int __init sensors_jc42_init(void)
{
        return i2c_add_driver(&jc42_driver);
}

static void __exit sensors_jc42_exit(void)
{
        i2c_del_driver(&jc42_driver);
}

MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
MODULE_DESCRIPTION("JC42 driver");
MODULE_LICENSE("GPL");

module_init(sensors_jc42_init);
module_exit(sensors_jc42_exit);