diff options
Diffstat (limited to 'drivers/hwmon/ds1621.c')
| -rw-r--r-- | drivers/hwmon/ds1621.c | 395 |
1 files changed, 395 insertions, 0 deletions
diff --git a/drivers/hwmon/ds1621.c b/drivers/hwmon/ds1621.c new file mode 100644 index 0000000000..21b6350465 --- /dev/null +++ b/drivers/hwmon/ds1621.c @@ -0,0 +1,395 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ds1621.c - Part of lm_sensors, Linux kernel modules for hardware + * monitoring + * Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23 + * based on lm75.c by Frodo Looijaard <frodol@dds.nl> + * Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with + * the help of Jean Delvare <jdelvare@suse.de> + * + * The DS1621 device is a digital temperature/thermometer with 9-bit + * resolution, a thermal alarm output (Tout), and user-defined minimum + * and maximum temperature thresholds (TH and TL). + * + * The DS1625, DS1631, DS1721, and DS1731 are pin compatible with the DS1621 + * and similar in operation, with slight variations as noted in the device + * datasheets (please refer to www.maximintegrated.com for specific + * device information). + * + * Since the DS1621 was the first chipset supported by this driver, + * most comments will refer to this chipset, but are actually general + * and concern all supported chipsets, unless mentioned otherwise. + */ + +#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> +#include <linux/sysfs.h> +#include <linux/kernel.h> + +/* Supported devices */ +enum chips { ds1621, ds1625, ds1631, ds1721, ds1731 }; + +/* Insmod parameters */ +static int polarity = -1; +module_param(polarity, int, 0); +MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low"); + +/* + * The Configuration/Status register + * + * - DS1621: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | X | X |POL |1SHOT| + * + * - DS1625: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| + * + * - DS1631, DS1731: + * 7 6 5 4 3 2 1 0 + * |Done|THF |TLF |NVB | R1 | R0 |POL |1SHOT| + * + * - DS1721: + * 7 6 5 4 3 2 1 0 + * |Done| X | X | U | R1 | R0 |POL |1SHOT| + * + * Where: + * - 'X' is Reserved + * - 'U' is Undefined + */ +#define DS1621_REG_CONFIG_NVB 0x10 +#define DS1621_REG_CONFIG_RESOL 0x0C +#define DS1621_REG_CONFIG_POLARITY 0x02 +#define DS1621_REG_CONFIG_1SHOT 0x01 +#define DS1621_REG_CONFIG_DONE 0x80 + +#define DS1621_REG_CONFIG_RESOL_SHIFT 2 + +/* ds1721 conversion rates: {C/LSB, time(ms), resolution bit setting} */ +static const unsigned short ds1721_convrates[] = { + 94, /* 9-bits (0.5, 93.75, RES[0..1] = 0 */ + 188, /* 10-bits (0.25, 187.5, RES[0..1] = 1 */ + 375, /* 11-bits (0.125, 375, RES[0..1] = 2 */ + 750, /* 12-bits (0.0625, 750, RES[0..1] = 3 */ +}; + +#define DS1621_CONVERSION_MAX 750 +#define DS1625_CONVERSION_MAX 500 + +#define DS1621_TEMP_MAX 125000 +#define DS1621_TEMP_MIN (-55000) + +/* The DS1621 temperature registers */ +static const u8 DS1621_REG_TEMP[3] = { + 0xAA, /* input, word, RO */ + 0xA2, /* min, word, RW */ + 0xA1, /* max, word, RW */ +}; +#define DS1621_REG_CONF 0xAC /* byte, RW */ +#define DS1621_COM_START 0xEE /* no data */ +#define DS1721_COM_START 0x51 /* no data */ +#define DS1621_COM_STOP 0x22 /* no data */ + +/* The DS1621 configuration register */ +#define DS1621_ALARM_TEMP_HIGH 0x40 +#define DS1621_ALARM_TEMP_LOW 0x20 + +/* Conversions */ +#define ALARMS_FROM_REG(val) ((val) & \ + (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW)) + +/* Each client has this additional data */ +struct ds1621_data { + struct i2c_client *client; + struct mutex update_lock; + bool valid; /* true if following fields are valid */ + unsigned long last_updated; /* In jiffies */ + enum chips kind; /* device type */ + + u16 temp[3]; /* Register values, word */ + u8 conf; /* Register encoding, combined */ + u8 zbits; /* Resolution encoded as number of + * zero bits */ + u16 update_interval; /* Conversion rate in milliseconds */ +}; + +static inline int DS1621_TEMP_FROM_REG(u16 reg) +{ + return DIV_ROUND_CLOSEST(((s16)reg / 16) * 625, 10); +} + +/* + * TEMP: 0.001C/bit (-55C to +125C) + * REG: + * - 1621, 1625: 0.5C/bit, 7 zero-bits + * - 1631, 1721, 1731: 0.0625C/bit, 4 zero-bits + */ +static inline u16 DS1621_TEMP_TO_REG(long temp, u8 zbits) +{ + temp = clamp_val(temp, DS1621_TEMP_MIN, DS1621_TEMP_MAX); + temp = DIV_ROUND_CLOSEST(temp * (1 << (8 - zbits)), 1000) << zbits; + return temp; +} + +static void ds1621_init_client(struct ds1621_data *data, + struct i2c_client *client) +{ + u8 conf, new_conf, sreg, resol; + + new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); + /* switch to continuous conversion mode */ + new_conf &= ~DS1621_REG_CONFIG_1SHOT; + + /* setup output polarity */ + if (polarity == 0) + new_conf &= ~DS1621_REG_CONFIG_POLARITY; + else if (polarity == 1) + new_conf |= DS1621_REG_CONFIG_POLARITY; + + if (conf != new_conf) + i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf); + + switch (data->kind) { + case ds1625: + data->update_interval = DS1625_CONVERSION_MAX; + data->zbits = 7; + sreg = DS1621_COM_START; + break; + case ds1631: + case ds1721: + case ds1731: + resol = (new_conf & DS1621_REG_CONFIG_RESOL) >> + DS1621_REG_CONFIG_RESOL_SHIFT; + data->update_interval = ds1721_convrates[resol]; + data->zbits = 7 - resol; + sreg = DS1721_COM_START; + break; + default: + data->update_interval = DS1621_CONVERSION_MAX; + data->zbits = 7; + sreg = DS1621_COM_START; + break; + } + + /* start conversion */ + i2c_smbus_write_byte(client, sreg); +} + +static struct ds1621_data *ds1621_update_client(struct device *dev) +{ + struct ds1621_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + u8 new_conf; + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + data->update_interval) || + !data->valid) { + int i; + + dev_dbg(&client->dev, "Starting ds1621 update\n"); + + data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); + + for (i = 0; i < ARRAY_SIZE(data->temp); i++) + data->temp[i] = i2c_smbus_read_word_swapped(client, + DS1621_REG_TEMP[i]); + + /* reset alarms if necessary */ + new_conf = data->conf; + if (data->temp[0] > data->temp[1]) /* input > min */ + new_conf &= ~DS1621_ALARM_TEMP_LOW; + if (data->temp[0] < data->temp[2]) /* input < max */ + new_conf &= ~DS1621_ALARM_TEMP_HIGH; + if (data->conf != new_conf) + i2c_smbus_write_byte_data(client, DS1621_REG_CONF, + new_conf); + + data->last_updated = jiffies; + data->valid = true; + } + + mutex_unlock(&data->update_lock); + + return data; +} + +static ssize_t temp_show(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ds1621_data *data = ds1621_update_client(dev); + return sprintf(buf, "%d\n", + DS1621_TEMP_FROM_REG(data->temp[attr->index])); +} + +static ssize_t temp_store(struct device *dev, struct device_attribute *da, + const char *buf, size_t count) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ds1621_data *data = dev_get_drvdata(dev); + long val; + int err; + + err = kstrtol(buf, 10, &val); + if (err) + return err; + + mutex_lock(&data->update_lock); + data->temp[attr->index] = DS1621_TEMP_TO_REG(val, data->zbits); + i2c_smbus_write_word_swapped(data->client, DS1621_REG_TEMP[attr->index], + data->temp[attr->index]); + mutex_unlock(&data->update_lock); + return count; +} + +static ssize_t alarms_show(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct ds1621_data *data = ds1621_update_client(dev); + return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf)); +} + +static ssize_t alarm_show(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ds1621_data *data = ds1621_update_client(dev); + return sprintf(buf, "%d\n", !!(data->conf & attr->index)); +} + +static ssize_t update_interval_show(struct device *dev, + struct device_attribute *da, char *buf) +{ + struct ds1621_data *data = dev_get_drvdata(dev); + return sysfs_emit(buf, "%hu\n", data->update_interval); +} + +static ssize_t update_interval_store(struct device *dev, + struct device_attribute *da, + const char *buf, size_t count) +{ + struct ds1621_data *data = dev_get_drvdata(dev); + struct i2c_client *client = data->client; + unsigned long convrate; + s32 err; + int resol = 0; + + err = kstrtoul(buf, 10, &convrate); + if (err) + return err; + + /* Convert rate into resolution bits */ + while (resol < (ARRAY_SIZE(ds1721_convrates) - 1) && + convrate > ds1721_convrates[resol]) + resol++; + + mutex_lock(&data->update_lock); + data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF); + data->conf &= ~DS1621_REG_CONFIG_RESOL; + data->conf |= (resol << DS1621_REG_CONFIG_RESOL_SHIFT); + i2c_smbus_write_byte_data(client, DS1621_REG_CONF, data->conf); + data->update_interval = ds1721_convrates[resol]; + data->zbits = 7 - resol; + mutex_unlock(&data->update_lock); + + return count; +} + +static DEVICE_ATTR_RO(alarms); +static DEVICE_ATTR_RW(update_interval); + +static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0); +static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1); +static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2); +static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS1621_ALARM_TEMP_LOW); +static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS1621_ALARM_TEMP_HIGH); + +static struct attribute *ds1621_attributes[] = { + &sensor_dev_attr_temp1_input.dev_attr.attr, + &sensor_dev_attr_temp1_min.dev_attr.attr, + &sensor_dev_attr_temp1_max.dev_attr.attr, + &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, + &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, + &dev_attr_alarms.attr, + &dev_attr_update_interval.attr, + NULL +}; + +static umode_t ds1621_attribute_visible(struct kobject *kobj, + struct attribute *attr, int index) +{ + struct device *dev = kobj_to_dev(kobj); + struct ds1621_data *data = dev_get_drvdata(dev); + + if (attr == &dev_attr_update_interval.attr) + if (data->kind == ds1621 || data->kind == ds1625) + /* shhh, we're hiding update_interval */ + return 0; + return attr->mode; +} + +static const struct attribute_group ds1621_group = { + .attrs = ds1621_attributes, + .is_visible = ds1621_attribute_visible +}; +__ATTRIBUTE_GROUPS(ds1621); + +static const struct i2c_device_id ds1621_id[]; + +static int ds1621_probe(struct i2c_client *client) +{ + struct ds1621_data *data; + struct device *hwmon_dev; + + data = devm_kzalloc(&client->dev, sizeof(struct ds1621_data), + GFP_KERNEL); + if (!data) + return -ENOMEM; + + mutex_init(&data->update_lock); + + data->kind = i2c_match_id(ds1621_id, client)->driver_data; + data->client = client; + + /* Initialize the DS1621 chip */ + ds1621_init_client(data, client); + + hwmon_dev = devm_hwmon_device_register_with_groups(&client->dev, + client->name, data, + ds1621_groups); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id ds1621_id[] = { + { "ds1621", ds1621 }, + { "ds1625", ds1625 }, + { "ds1631", ds1631 }, + { "ds1721", ds1721 }, + { "ds1731", ds1731 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, ds1621_id); + +/* This is the driver that will be inserted */ +static struct i2c_driver ds1621_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "ds1621", + }, + .probe = ds1621_probe, + .id_table = ds1621_id, +}; + +module_i2c_driver(ds1621_driver); + +MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>"); +MODULE_DESCRIPTION("DS1621 driver"); +MODULE_LICENSE("GPL"); |