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Subject[PATCH 1/1] [hwmon] nct1008: Initial NCT1008 driver
Date
From: Andrew Chew <achew@nvidia.com>

This is a digital temperature sensor I2C peripheral from ON Semiconductor.

Signed-off-by: Andrew Chew <achew@nvidia.com>
---
drivers/hwmon/Kconfig | 11 ++
drivers/hwmon/Makefile | 1 +
drivers/hwmon/nct1008.c | 423 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 435 insertions(+), 0 deletions(-)
create mode 100644 drivers/hwmon/nct1008.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 060ef63..daa6159 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -738,6 +738,17 @@ config SENSORS_MAX6650
This driver can also be built as a module. If so, the module
will be called max6650.

+config SENSORS_NCT1008
+ tristate "ON Semiconductor Temperature Sensor"
+ default n
+ depends on I2C
+ help
+ Say yes here if you wish to include the ON Semiconductor
+ NCT1008 Temperature sensor.
+
+ This driver can also be built as a module. If so, the module
+ will be called nct1008.
+
config SENSORS_PC87360
tristate "National Semiconductor PC87360 family"
select HWMON_VID
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 967d0ea..803893c 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -87,6 +87,7 @@ obj-$(CONFIG_SENSORS_MAX1619) += max1619.o
obj-$(CONFIG_SENSORS_MAX6639) += max6639.o
obj-$(CONFIG_SENSORS_MAX6650) += max6650.o
obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o
+obj-$(CONFIG_SENSORS_NCT1008) += nct1008.o
obj-$(CONFIG_SENSORS_PC87360) += pc87360.o
obj-$(CONFIG_SENSORS_PC87427) += pc87427.o
obj-$(CONFIG_SENSORS_PCF8591) += pcf8591.o
diff --git a/drivers/hwmon/nct1008.c b/drivers/hwmon/nct1008.c
new file mode 100644
index 0000000..ebae3b6
--- /dev/null
+++ b/drivers/hwmon/nct1008.c
@@ -0,0 +1,423 @@
+/*
+ * Driver for NCT1008, temperature monitoring device from ON Semiconductors
+ *
+ * Copyright (c) 2010, NVIDIA Corporation.
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+
+#include <linux/nct1008.h>
+#include <linux/hwmon.h>
+
+#define DRIVER_NAME "nct1008"
+
+/* Register Addresses */
+#define LOCAL_TEMP_RD 0x00
+#define EXT_HI_TEMP_RD 0x01
+#define EXT_LO_TEMP_RD 0x10
+#define STATUS_RD 0x02
+#define CONFIG_RD 0x03
+
+#define CONFIG_WR 0x09
+#define CONV_RATE_WR 0x0A
+#define LOCAL_TEMP_HI_LIMIT_WR 0x0B
+#define EXT_TEMP_HI_LIMIT_HI_BYTE 0x0D
+#define OFFSET_WR 0x11
+#define EXT_THERM_LIMIT_WR 0x19
+#define LOCAL_THERM_LIMIT_WR 0x20
+#define THERM_HYSTERESIS_WR 0x21
+
+/* Configuration Register Bits */
+#define EXTENDED_RANGE_BIT (0x1 << 2)
+#define THERM2_BIT (0x1 << 5)
+#define STANDBY_BIT (0x1 << 6)
+
+/* Max Temperature Measurements */
+#define EXTENDED_RANGE_OFFSET 64U
+#define STANDARD_RANGE_MAX 127U
+#define EXTENDED_RANGE_MAX (150U + EXTENDED_RANGE_OFFSET)
+
+static inline u8 temperature_to_value(bool extended, u8 temp);
+
+struct nct1008_data {
+ struct device *hwmon_dev;
+ struct work_struct work;
+ struct i2c_client *client;
+ struct mutex mutex;
+ u8 config;
+ void (*alarm_fn)(bool raised);
+};
+
+static ssize_t nct1008_show_temp(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ signed int temp_value = 0;
+ u8 data = 0;
+
+ if (!dev || !buf || !attr)
+ return -EINVAL;
+
+ data = i2c_smbus_read_byte_data(client, LOCAL_TEMP_RD);
+ if (data < 0) {
+ dev_err(&client->dev, "%s: failed to read "
+ "temperature\n", __func__);
+ return -EINVAL;
+ }
+
+ temp_value = (signed int)data;
+ return sprintf(buf, "%d\n", temp_value);
+}
+
+static ssize_t nct1008_show_ext_temp(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ signed int temp_value = 0;
+ u8 data = 0;
+
+ if (!dev || !buf || !attr)
+ return -EINVAL;
+
+ data = i2c_smbus_read_byte_data(client, EXT_HI_TEMP_RD);
+ if (data < 0) {
+ dev_err(&client->dev, "%s: failed to read "
+ "ext_temperature\n", __func__);
+ return -EINVAL;
+ }
+
+ temp_value = (signed int)data;
+
+ data = i2c_smbus_read_byte_data(client, EXT_LO_TEMP_RD);
+
+ return sprintf(buf, "%d.%d\n", temp_value, (25 * (data >> 6)));
+}
+
+static ssize_t nct1008_store_throttle_ext_limit(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct nct1008_platform_data *pdata = client->dev.platform_data;
+ unsigned long res;
+ u8 ext_limit;
+ u8 value;
+ int err;
+
+ err = strict_strtoul(buf, 0, &res);
+ if (err)
+ return -EINVAL;
+
+ ext_limit = (u8)res;
+
+ /* External Temperature Throttling limit */
+ value = temperature_to_value(pdata->ext_range, ext_limit);
+ err = i2c_smbus_write_byte_data(client,
+ EXT_TEMP_HI_LIMIT_HI_BYTE, value);
+ if (err < 0)
+ return -EINVAL;
+
+ pdata->throttling_ext_limit = ext_limit;
+ return count;
+}
+
+static ssize_t nct1008_show_throttle_ext_limit(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+ struct nct1008_platform_data *pdata = client->dev.platform_data;
+ u8 ext_limit = 0;
+
+ if (!dev || !buf || !attr)
+ return -EINVAL;
+
+ ext_limit = pdata->throttling_ext_limit;
+
+ return sprintf(buf, "%d\n", ext_limit);
+}
+
+static DEVICE_ATTR(temperature, S_IRUGO, nct1008_show_temp, NULL);
+static DEVICE_ATTR(ext_temperature, S_IRUGO, nct1008_show_ext_temp, NULL);
+static DEVICE_ATTR(throttle_ext_limit, S_IRUGO | S_IWUSR,
+ nct1008_show_throttle_ext_limit,
+ nct1008_store_throttle_ext_limit);
+
+static struct attribute *nct1008_attributes[] = {
+ &dev_attr_temperature.attr,
+ &dev_attr_ext_temperature.attr,
+ &dev_attr_throttle_ext_limit.attr,
+ NULL
+};
+
+static const struct attribute_group nct1008_attr_group = {
+ .attrs = nct1008_attributes,
+};
+
+static void nct1008_enable(struct i2c_client *client)
+{
+ struct nct1008_data *data = i2c_get_clientdata(client);
+
+ i2c_smbus_write_byte_data(client, CONFIG_WR,
+ data->config & ~STANDBY_BIT);
+}
+
+static void nct1008_disable(struct i2c_client *client)
+{
+ struct nct1008_data *data = i2c_get_clientdata(client);
+
+ i2c_smbus_write_byte_data(client, CONFIG_WR,
+ data->config | STANDBY_BIT);
+}
+
+
+static void nct1008_work_func(struct work_struct *work)
+{
+ struct nct1008_data *data =
+ container_of(work, struct nct1008_data, work);
+ int irq = data->client->irq;
+
+ mutex_lock(&data->mutex);
+
+ if (data->alarm_fn) {
+ /* Therm2 line is active low */
+ data->alarm_fn(!gpio_get_value(irq_to_gpio(irq)));
+ }
+
+ mutex_unlock(&data->mutex);
+}
+
+static irqreturn_t nct1008_irq(int irq, void *dev_id)
+{
+ struct nct1008_data *data = dev_id;
+ schedule_work(&data->work);
+
+ return IRQ_HANDLED;
+}
+
+static inline u8 value_to_temperature(bool extended, u8 value)
+{
+ return extended ? (u8)(value - EXTENDED_RANGE_OFFSET) : value;
+}
+
+static inline u8 temperature_to_value(bool extended, u8 temp)
+{
+ return extended ? (u8)(temp + EXTENDED_RANGE_OFFSET) : temp;
+}
+
+static int __devinit nct1008_configure_sensor(struct nct1008_data* data)
+{
+ struct i2c_client *client = data->client;
+ struct nct1008_platform_data *pdata = client->dev.platform_data;
+ u8 value;
+ int err;
+
+ if (!pdata || !pdata->supported_hwrev)
+ return -ENODEV;
+
+ /*
+ * Initial Configuration - device is placed in standby and
+ * ALERT/THERM2 pin is configured as THERM2
+ */
+ data->config = value = pdata->ext_range ?
+ (STANDBY_BIT | THERM2_BIT | EXTENDED_RANGE_BIT) :
+ (STANDBY_BIT | THERM2_BIT);
+
+ err = i2c_smbus_write_byte_data(client, CONFIG_WR, value);
+ if (err < 0)
+ goto error;
+
+ /* Temperature conversion rate */
+ err = i2c_smbus_write_byte_data(client, CONV_RATE_WR, pdata->conv_rate);
+ if (err < 0)
+ goto error;
+
+ /* External temperature h/w shutdown limit */
+ value = temperature_to_value(pdata->ext_range,
+ pdata->shutdown_ext_limit);
+ err = i2c_smbus_write_byte_data(client, EXT_THERM_LIMIT_WR, value);
+ if (err < 0)
+ goto error;
+
+ /* Local temperature h/w shutdown limit */
+ value = temperature_to_value(pdata->ext_range,
+ pdata->shutdown_local_limit);
+ err = i2c_smbus_write_byte_data(client, LOCAL_THERM_LIMIT_WR, value);
+ if (err < 0)
+ goto error;
+
+ /* External Temperature Throttling limit */
+ value = temperature_to_value(pdata->ext_range,
+ pdata->throttling_ext_limit);
+ err = i2c_smbus_write_byte_data(client, EXT_TEMP_HI_LIMIT_HI_BYTE,
+ value);
+ if (err < 0)
+ goto error;
+
+ /* Local Temperature Throttling limit */
+ value = pdata->ext_range ? EXTENDED_RANGE_MAX : STANDARD_RANGE_MAX;
+ err = i2c_smbus_write_byte_data(client, LOCAL_TEMP_HI_LIMIT_WR, value);
+ if (err < 0)
+ goto error;
+
+ /* Remote channel offset */
+ err = i2c_smbus_write_byte_data(client, OFFSET_WR, pdata->offset);
+ if (err < 0)
+ goto error;
+
+ /* THERM hysteresis */
+ err = i2c_smbus_write_byte_data(client, THERM_HYSTERESIS_WR,
+ pdata->hysteresis);
+ if (err < 0)
+ goto error;
+
+ data->alarm_fn = pdata->alarm_fn;
+ return 0;
+error:
+ return err;
+}
+
+static int __devinit nct1008_configure_irq(struct nct1008_data *data)
+{
+ INIT_WORK(&data->work, nct1008_work_func);
+
+ return request_irq(data->client->irq, nct1008_irq, IRQF_TRIGGER_RISING |
+ IRQF_TRIGGER_FALLING, DRIVER_NAME, data);
+}
+
+static int __devinit nct1008_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct nct1008_data *data;
+ int err;
+
+ data = kzalloc(sizeof(struct nct1008_data), GFP_KERNEL);
+
+ if (!data)
+ return -ENOMEM;
+
+ data->client = client;
+ i2c_set_clientdata(client, data);
+ mutex_init(&data->mutex);
+
+ err = nct1008_configure_sensor(data); /* sensor is in standby */
+ if (err < 0)
+ goto error;
+
+ err = nct1008_configure_irq(data);
+ if (err < 0)
+ goto error;
+
+ data->hwmon_dev = hwmon_device_register(&client->dev);
+ if (IS_ERR(data->hwmon_dev)) {
+ err = PTR_ERR(data->hwmon_dev);
+ dev_err(&client->dev, "%s: hwmon_device_register "
+ "failed\n", __func__);
+ goto error;
+ }
+
+ /* register sysfs hooks */
+ err = sysfs_create_group(&client->dev.kobj, &nct1008_attr_group);
+ if (err < 0)
+ goto fail_sys;
+
+ nct1008_enable(client); /* sensor is running */
+
+ schedule_work(&data->work); /* check initial state */
+
+ return 0;
+
+fail_sys:
+ hwmon_device_unregister(data->hwmon_dev);
+error:
+ kfree(data);
+ return err;
+}
+
+static int __devexit nct1008_remove(struct i2c_client *client)
+{
+ struct nct1008_data *data = i2c_get_clientdata(client);
+
+ free_irq(data->client->irq, data);
+ cancel_work_sync(&data->work);
+ hwmon_device_unregister(data->hwmon_dev);
+ sysfs_remove_group(&client->dev.kobj, &nct1008_attr_group);
+ kfree(data);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int nct1008_suspend(struct i2c_client *client, pm_message_t state)
+{
+ disable_irq(client->irq);
+ nct1008_disable(client);
+
+ return 0;
+}
+
+static int nct1008_resume(struct i2c_client *client)
+{
+ struct nct1008_data *data = i2c_get_clientdata(client);
+
+ nct1008_enable(client);
+ enable_irq(client->irq);
+ schedule_work(&data->work);
+
+ return 0;
+}
+#endif
+
+static const struct i2c_device_id nct1008_id[] = {
+ { DRIVER_NAME, 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, nct1008_id);
+
+static struct i2c_driver nct1008_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ },
+ .probe = nct1008_probe,
+ .remove = __devexit_p(nct1008_remove),
+ .id_table = nct1008_id,
+#ifdef CONFIG_PM
+ .suspend = nct1008_suspend,
+ .resume = nct1008_resume,
+#endif
+};
+
+static int __init nct1008_init(void)
+{
+ return i2c_add_driver(&nct1008_driver);
+}
+
+static void __exit nct1008_exit(void)
+{
+ i2c_del_driver(&nct1008_driver);
+}
+
+MODULE_DESCRIPTION("Temperature sensor driver for OnSemi NCT1008");
+MODULE_LICENSE("GPL");
+
+module_init(nct1008_init);
+module_exit(nct1008_exit);
--
1.7.0.4


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