diff options
Diffstat (limited to 'drivers/hwmon/ds620.c')
| -rw-r--r-- | drivers/hwmon/ds620.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/drivers/hwmon/ds620.c b/drivers/hwmon/ds620.c new file mode 100644 index 000000000000..257957c69d92 --- /dev/null +++ b/drivers/hwmon/ds620.c @@ -0,0 +1,337 @@ +/* + * ds620.c - Support for temperature sensor and thermostat DS620 + * + * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> + * + * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net> + * + * 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> +#include <linux/sysfs.h> +#include <linux/i2c/ds620.h> + +/* + * Many DS620 constants specified below + * 15 14 13 12 11 10 09 08 + * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT| + * + * 07 06 05 04 03 02 01 00 + * |PO2 |PO1 |A2 |A1 |A0 | | | | + */ +#define DS620_REG_CONFIG_DONE 0x8000 +#define DS620_REG_CONFIG_NVB 0x4000 +#define DS620_REG_CONFIG_THF 0x2000 +#define DS620_REG_CONFIG_TLF 0x1000 +#define DS620_REG_CONFIG_R1 0x0800 +#define DS620_REG_CONFIG_R0 0x0400 +#define DS620_REG_CONFIG_AUTOC 0x0200 +#define DS620_REG_CONFIG_1SHOT 0x0100 +#define DS620_REG_CONFIG_PO2 0x0080 +#define DS620_REG_CONFIG_PO1 0x0040 +#define DS620_REG_CONFIG_A2 0x0020 +#define DS620_REG_CONFIG_A1 0x0010 +#define DS620_REG_CONFIG_A0 0x0008 + +/* The DS620 registers */ +static const u8 DS620_REG_TEMP[3] = { + 0xAA, /* input, word, RO */ + 0xA2, /* min, word, RW */ + 0xA0, /* max, word, RW */ +}; + +#define DS620_REG_CONF 0xAC /* word, RW */ +#define DS620_COM_START 0x51 /* no data */ +#define DS620_COM_STOP 0x22 /* no data */ + +/* Each client has this additional data */ +struct ds620_data { + struct device *hwmon_dev; + struct mutex update_lock; + char valid; /* !=0 if following fields are valid */ + unsigned long last_updated; /* In jiffies */ + + u16 temp[3]; /* Register values, word */ +}; + +/* + * Temperature registers are word-sized. + * DS620 uses a high-byte first convention, which is exactly opposite to + * the SMBus standard. + */ +static int ds620_read_temp(struct i2c_client *client, u8 reg) +{ + int ret; + + ret = i2c_smbus_read_word_data(client, reg); + if (ret < 0) + return ret; + return swab16(ret); +} + +static int ds620_write_temp(struct i2c_client *client, u8 reg, u16 value) +{ + return i2c_smbus_write_word_data(client, reg, swab16(value)); +} + +static void ds620_init_client(struct i2c_client *client) +{ + struct ds620_platform_data *ds620_info = client->dev.platform_data; + u16 conf, new_conf; + + new_conf = conf = + swab16(i2c_smbus_read_word_data(client, DS620_REG_CONF)); + + /* switch to continuous conversion mode */ + new_conf &= ~DS620_REG_CONFIG_1SHOT; + /* already high at power-on, but don't trust the BIOS! */ + new_conf |= DS620_REG_CONFIG_PO2; + /* thermostat mode according to platform data */ + if (ds620_info && ds620_info->pomode == 1) + new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */ + else if (ds620_info && ds620_info->pomode == 2) + new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */ + else + new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */ + /* with highest precision */ + new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0; + + if (conf != new_conf) + i2c_smbus_write_word_data(client, DS620_REG_CONF, + swab16(new_conf)); + + /* start conversion */ + i2c_smbus_write_byte(client, DS620_COM_START); +} + +static struct ds620_data *ds620_update_client(struct device *dev) +{ + struct i2c_client *client = to_i2c_client(dev); + struct ds620_data *data = i2c_get_clientdata(client); + struct ds620_data *ret = data; + + mutex_lock(&data->update_lock); + + if (time_after(jiffies, data->last_updated + HZ + HZ / 2) + || !data->valid) { + int i; + int res; + + dev_dbg(&client->dev, "Starting ds620 update\n"); + + for (i = 0; i < ARRAY_SIZE(data->temp); i++) { + res = ds620_read_temp(client, + DS620_REG_TEMP[i]); + if (res < 0) { + ret = ERR_PTR(res); + goto abort; + } + + data->temp[i] = res; + } + + data->last_updated = jiffies; + data->valid = 1; + } +abort: + mutex_unlock(&data->update_lock); + + return ret; +} + +static ssize_t show_temp(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ds620_data *data = ds620_update_client(dev); + + if (IS_ERR(data)) + return PTR_ERR(data); + + return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10); +} + +static ssize_t set_temp(struct device *dev, struct device_attribute *da, + const char *buf, size_t count) +{ + int res; + long val; + + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct i2c_client *client = to_i2c_client(dev); + struct ds620_data *data = i2c_get_clientdata(client); + + res = strict_strtol(buf, 10, &val); + + if (res) + return res; + + val = (val * 10 / 625) * 8; + + mutex_lock(&data->update_lock); + data->temp[attr->index] = val; + ds620_write_temp(client, DS620_REG_TEMP[attr->index], + data->temp[attr->index]); + mutex_unlock(&data->update_lock); + return count; +} + +static ssize_t show_alarm(struct device *dev, struct device_attribute *da, + char *buf) +{ + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct ds620_data *data = ds620_update_client(dev); + struct i2c_client *client = to_i2c_client(dev); + u16 conf, new_conf; + int res; + + if (IS_ERR(data)) + return PTR_ERR(data); + + /* reset alarms if necessary */ + res = i2c_smbus_read_word_data(client, DS620_REG_CONF); + if (res < 0) + return res; + + conf = swab16(res); + new_conf = conf; + new_conf &= ~attr->index; + if (conf != new_conf) { + res = i2c_smbus_write_word_data(client, DS620_REG_CONF, + swab16(new_conf)); + if (res < 0) + return res; + } + + return sprintf(buf, "%d\n", !!(conf & attr->index)); +} + +static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); +static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); +static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, + DS620_REG_CONFIG_TLF); +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, + DS620_REG_CONFIG_THF); + +static struct attribute *ds620_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, + NULL +}; + +static const struct attribute_group ds620_group = { + .attrs = ds620_attributes, +}; + +static int ds620_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct ds620_data *data; + int err; + + data = kzalloc(sizeof(struct ds620_data), GFP_KERNEL); + if (!data) { + err = -ENOMEM; + goto exit; + } + + i2c_set_clientdata(client, data); + mutex_init(&data->update_lock); + + /* Initialize the DS620 chip */ + ds620_init_client(client); + + /* Register sysfs hooks */ + err = sysfs_create_group(&client->dev.kobj, &ds620_group); + if (err) + goto exit_free; + + data->hwmon_dev = hwmon_device_register(&client->dev); + if (IS_ERR(data->hwmon_dev)) { + err = PTR_ERR(data->hwmon_dev); + goto exit_remove_files; + } + + dev_info(&client->dev, "temperature sensor found\n"); + + return 0; + +exit_remove_files: + sysfs_remove_group(&client->dev.kobj, &ds620_group); +exit_free: + kfree(data); +exit: + return err; +} + +static int ds620_remove(struct i2c_client *client) +{ + struct ds620_data *data = i2c_get_clientdata(client); + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&client->dev.kobj, &ds620_group); + + kfree(data); + + return 0; +} + +static const struct i2c_device_id ds620_id[] = { + {"ds620", 0}, + {} +}; + +MODULE_DEVICE_TABLE(i2c, ds620_id); + +/* This is the driver that will be inserted */ +static struct i2c_driver ds620_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "ds620", + }, + .probe = ds620_probe, + .remove = ds620_remove, + .id_table = ds620_id, +}; + +static int __init ds620_init(void) +{ + return i2c_add_driver(&ds620_driver); +} + +static void __exit ds620_exit(void) +{ + i2c_del_driver(&ds620_driver); +} + +MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); +MODULE_DESCRIPTION("DS620 driver"); +MODULE_LICENSE("GPL"); + +module_init(ds620_init); +module_exit(ds620_exit); |