hwmon: Support for Dallas Semiconductor DS620

Driver for Dallas Semiconductor DS620 temperature sensor and thermostat

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

3 files changed, 348 insertions, 0 deletions

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 0f09567257fd..bdc13d28b1ea 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 20e74086e681..dde02d99c238 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 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);