Hi,
On 08/01/11 19:54, Guenter Roeck wrote:
> couple of comments below.
Thanks again for your suggestions! I'm attaching the latest version with
your ideas included.
>> +The PO output pin is always active-low.
>
> What is the point of configuring PO1 if you set PO2 such that PO is always low ?
Maybe the above was a bit misleading, though correct: "always
active-low" wasn't intended to mean "always low", but instead "low when
active". :-) Nevertheless, I clarified it. ("The PO output pin of the
DS620 operates active-low.").
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..0c765b0
--- /dev/null
+++ b/Documentation/hwmon/ds620
@@ -0,0 +1,34 @@
+Kernel driver ds620
+===================
+
+Supported chips:
+ * Dallas Semiconductor DS620
+ Prefix: 'ds620'
+ 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) .pomode == 0 (default), the thermostat output pin
+PO is always low. If .pomode == 1, the thermostat is in TH_LOW mode. I.e., the
+output pin PO becomes active when the temperature falls below temp1_min and
+stays active until the temperature goes above temp1_max.
+
+Likewise, with .pomode == 2, the thermostat is in TH_HIGH mode. I.e., the PO
+output pin becomes active when the temperature goes above temp1_max and stays
+active until the temperature falls below temp1_min.
+
+The PO output pin of the DS620 operates 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..624950d
--- /dev/null
+++ b/drivers/hwmon/ds620.c
@@ -0,0 +1,335 @@
+/*
+ * 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>
+
+/*
+ * 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;
+ /* thermostat mode according to platform data */
+ if (ds620_info && ds620_info->pomode == 1)
+ new_conf &= ~DS620_REG_CONFIG_PO1; /* TH_LOW */
+ else if (ds620_info && ds620_info->pomode == 2)
+ new_conf |= DS620_REG_CONFIG_PO1; /* TH_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@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..141c043
--- /dev/null
+++ b/include/linux/i2c/ds620.h
@@ -0,0 +1,21 @@
+#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 output pin PO mode:
+ * 0 = always low (default)
+ * 1 = TH_LOW
+ * 2 = TH_HIGH
+ *
+ * (see Documentation/hwmon/ds620)
+ */
+ bool pomode;
+};
+
+#endif /* _LINUX_DS620_H */
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