Hi, On 07/01/11 12:34, Guenter Roeck wrote: >> What can we do if we want to make it configurable at runtime? I'm not >> using it currently this way, but users could be. Or should we just make >> ist platform data to adhere to spec restrictions? >> > I would suggest to implement it as platform data. If anyone ever needs it runtime-configurable, > we can still think about some way to do it. I'm attaching the updated patch according to your suggestions, including Documentation updates. :-) Thanks, Roland
HWMON driver for Dallas Semiconductor DS620 temperature sensor and thermostat Signed-off-by: Roland Stigge <stigge@xxxxxxxxx> diff --git a/Documentation/hwmon/ds620 b/Documentation/hwmon/ds620 new file mode 100644 index 0000000..c0edc34 --- /dev/null +++ b/Documentation/hwmon/ds620 @@ -0,0 +1,34 @@ +Kernel driver ds620 +=================== + +Supported chips: + * Dallas Semiconductor DS620 + Prefix: 'ds620' + Addresses scanned: I2C 0x48 - 0x4f + Datasheet: Publicly available at the Dallas Semiconductor website + http://www.dalsemi.com/ + +Authors: + Roland Stigge <stigge@xxxxxxxxx> + based on ds1621.c by + Christian W. Zuckschwerdt <zany@xxxxxxxx> + +Description +----------- + +The DS620 is a (one instance) digital thermometer and thermostat. It has both +high and low temperature limits which can be user defined (i.e. programmed +into non-volatile on-chip registers). Temperature range is -55 degree Celsius +to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value +returned via sysfs displays post decimal positions. + +The thermostat function works as follows: When configured via platform_data +(struct ds620_platform_data) .thmode == 0 (default), the thermostat is in +TH_LOW mode. I.e., the alarm becomes active when the temperature falls below +temp1_min and stays active until the temperature goes above temp1_max. + +Likewise, with .thmode == 1, the thermostat is in TH_HIGH mode. I.e., the alarm +becomes active when the temperature goes above temp1_max and stays active until +the temperature falls below temp1_min. + +The PO output pin is always active-low. diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index a56f6ad..700389a 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -274,6 +274,16 @@ config SENSORS_ATXP1 This driver can also be built as a module. If so, the module will be called atxp1. +config SENSORS_DS620 + tristate "Dallas Semiconductor DS620" + depends on I2C + help + If you say yes here you get support for Dallas Semiconductor + DS620 sensor chip. + + This driver can also be built as a module. If so, the module + will be called ds620. + config SENSORS_DS1621 tristate "Dallas Semiconductor DS1621 and DS1625" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 2479b3d..42542d7 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -41,6 +41,7 @@ obj-$(CONFIG_SENSORS_ATXP1) += atxp1.o obj-$(CONFIG_SENSORS_CORETEMP) += coretemp.o obj-$(CONFIG_SENSORS_PKGTEMP) += pkgtemp.o obj-$(CONFIG_SENSORS_DME1737) += dme1737.o +obj-$(CONFIG_SENSORS_DS620) += ds620.o obj-$(CONFIG_SENSORS_DS1621) += ds1621.o obj-$(CONFIG_SENSORS_EMC1403) += emc1403.o obj-$(CONFIG_SENSORS_EMC2103) += emc2103.o diff --git a/drivers/hwmon/ds620.c b/drivers/hwmon/ds620.c new file mode 100644 index 0000000..62e4f0d --- /dev/null +++ b/drivers/hwmon/ds620.c @@ -0,0 +1,344 @@ +/* + ds620.c - Support for temperature sensor and thermostat DS620 + + Copyright (C) 2010, 2011 Roland Stigge <stigge@xxxxxxxxx> + + based on ds1621.c by Christian W. Zuckschwerdt <zany@xxxxxxxx> + + 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> + +/* Addresses to scan */ +static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, + 0x4d, 0x4e, 0x4f, I2C_CLIENT_END +}; + +/* 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 */ + u16 conf; /* Register encoding, combined */ +}; + +/* 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_data *data = i2c_get_clientdata(client); + struct ds620_platform_data *ds620_info = + (struct ds620_platform_data *)&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); + /* thermostat mode according to platform data */ + if (ds620_info && ds620_info->thmode) + new_conf |= DS620_REG_CONFIG_PO1; /* TH_HIGH */ + else + new_conf &= ~DS620_REG_CONFIG_PO1; /* TH_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)); + } + + data->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 = 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 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; + + data->conf = swab16(res); + new_conf = data->conf; + if (data->temp[0] > data->temp[1]) /* input > min */ + new_conf &= ~DS620_REG_CONFIG_TLF; + if (data->temp[0] < data->temp[2]) /* input < max */ + new_conf &= ~DS620_REG_CONFIG_THF; + if (data->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", !!(data->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, + .address_list = normal_i2c, +}; + +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@xxxxxxxxx>"); +MODULE_DESCRIPTION("DS620 driver"); +MODULE_LICENSE("GPL"); + +module_init(ds620_init); +module_exit(ds620_exit); diff --git a/include/linux/i2c/ds620.h b/include/linux/i2c/ds620.h new file mode 100644 index 0000000..e9a4dcc --- /dev/null +++ b/include/linux/i2c/ds620.h @@ -0,0 +1,15 @@ +#ifndef _LINUX_DS620_H +#define _LINUX_DS620_H + +#include <linux/types.h> +#include <linux/i2c.h> + +/* platform data for the DS620 temperature sensor and thermostat */ + +struct ds620_platform_data { + /* Thermostat Mode: 0 = TH_LOW, 1 = TH_HIGH */ + /* (see Documentation/hwmon/ds620) */ + bool thmode; +}; + +#endif /* _LINUX_DS620_H */
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