Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / hwmon / ad7314.c

diff --git a/kernel/drivers/hwmon/ad7314.c b/kernel/drivers/hwmon/ad7314.c
new file mode 100644 (file)
index 0000000..1195546
--- /dev/null
+++ b/kernel/drivers/hwmon/ad7314.c
@@ -0,0 +1,171 @@
+/*
+ * AD7314 digital temperature sensor driver for AD7314, ADT7301 and ADT7302
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ *
+ * Conversion to hwmon from IIO done by Jonathan Cameron <jic23@cam.ac.uk>
+ */
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/bitops.h>
+
+/*
+ * AD7314 temperature masks
+ */
+#define AD7314_TEMP_MASK               0x7FE0
+#define AD7314_TEMP_SHIFT              5
+
+/*
+ * ADT7301 and ADT7302 temperature masks
+ */
+#define ADT7301_TEMP_MASK              0x3FFF
+
+enum ad7314_variant {
+       adt7301,
+       adt7302,
+       ad7314,
+};
+
+struct ad7314_data {
+       struct spi_device       *spi_dev;
+       struct device           *hwmon_dev;
+       u16 rx ____cacheline_aligned;
+};
+
+static int ad7314_spi_read(struct ad7314_data *chip)
+{
+       int ret;
+
+       ret = spi_read(chip->spi_dev, (u8 *)&chip->rx, sizeof(chip->rx));
+       if (ret < 0) {
+               dev_err(&chip->spi_dev->dev, "SPI read error\n");
+               return ret;
+       }
+
+       return be16_to_cpu(chip->rx);
+}
+
+static ssize_t ad7314_show_temperature(struct device *dev,
+               struct device_attribute *attr,
+               char *buf)
+{
+       struct ad7314_data *chip = dev_get_drvdata(dev);
+       s16 data;
+       int ret;
+
+       ret = ad7314_spi_read(chip);
+       if (ret < 0)
+               return ret;
+       switch (spi_get_device_id(chip->spi_dev)->driver_data) {
+       case ad7314:
+               data = (ret & AD7314_TEMP_MASK) >> AD7314_TEMP_SHIFT;
+               data = sign_extend32(data, 9);
+
+               return sprintf(buf, "%d\n", 250 * data);
+       case adt7301:
+       case adt7302:
+               /*
+                * Documented as a 13 bit twos complement register
+                * with a sign bit - which is a 14 bit 2's complement
+                * register.  1lsb - 31.25 milli degrees centigrade
+                */
+               data = ret & ADT7301_TEMP_MASK;
+               data = sign_extend32(data, 13);
+
+               return sprintf(buf, "%d\n",
+                              DIV_ROUND_CLOSEST(data * 3125, 100));
+       default:
+               return -EINVAL;
+       }
+}
+
+static ssize_t ad7314_show_name(struct device *dev,
+                               struct device_attribute *devattr, char *buf)
+{
+       return sprintf(buf, "%s\n", to_spi_device(dev)->modalias);
+}
+
+static DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL);
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
+                         ad7314_show_temperature, NULL, 0);
+
+static struct attribute *ad7314_attributes[] = {
+       &dev_attr_name.attr,
+       &sensor_dev_attr_temp1_input.dev_attr.attr,
+       NULL,
+};
+
+static const struct attribute_group ad7314_group = {
+       .attrs = ad7314_attributes,
+};
+
+static int ad7314_probe(struct spi_device *spi_dev)
+{
+       int ret;
+       struct ad7314_data *chip;
+
+       chip = devm_kzalloc(&spi_dev->dev, sizeof(*chip), GFP_KERNEL);
+       if (chip == NULL)
+               return -ENOMEM;
+
+       spi_set_drvdata(spi_dev, chip);
+
+       ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
+       if (ret < 0)
+               return ret;
+
+       chip->hwmon_dev = hwmon_device_register(&spi_dev->dev);
+       if (IS_ERR(chip->hwmon_dev)) {
+               ret = PTR_ERR(chip->hwmon_dev);
+               goto error_remove_group;
+       }
+       chip->spi_dev = spi_dev;
+
+       return 0;
+error_remove_group:
+       sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
+       return ret;
+}
+
+static int ad7314_remove(struct spi_device *spi_dev)
+{
+       struct ad7314_data *chip = spi_get_drvdata(spi_dev);
+
+       hwmon_device_unregister(chip->hwmon_dev);
+       sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
+
+       return 0;
+}
+
+static const struct spi_device_id ad7314_id[] = {
+       { "adt7301", adt7301 },
+       { "adt7302", adt7302 },
+       { "ad7314", ad7314 },
+       { }
+};
+MODULE_DEVICE_TABLE(spi, ad7314_id);
+
+static struct spi_driver ad7314_driver = {
+       .driver = {
+               .name = "ad7314",
+               .owner = THIS_MODULE,
+       },
+       .probe = ad7314_probe,
+       .remove = ad7314_remove,
+       .id_table = ad7314_id,
+};
+
+module_spi_driver(ad7314_driver);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital temperature sensor driver");
+MODULE_LICENSE("GPL v2");