/* * 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 */ s16 temp[3]; /* Register values, word */ }; static void ds620_init_client(struct i2c_client *client) { struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev); u16 conf, new_conf; new_conf = conf = i2c_smbus_read_word_swapped(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_swapped(client, DS620_REG_CONF, 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 = i2c_smbus_read_word_swapped(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 = kstrtol(buf, 10, &val); if (res) return res; val = (val * 10 / 625) * 8; mutex_lock(&data->update_lock); data->temp[attr->index] = val; i2c_smbus_write_word_swapped(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_swapped(client, DS620_REG_CONF); if (res < 0) return res; new_conf = conf = res; new_conf &= ~attr->index; if (conf != new_conf) { res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF, 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 = devm_kzalloc(&client->dev, sizeof(struct ds620_data), GFP_KERNEL); if (!data) return -ENOMEM; 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) return err; 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); 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); 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, }; module_i2c_driver(ds620_driver); MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); MODULE_DESCRIPTION("DS620 driver"); MODULE_LICENSE("GPL");