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authorJonathan Cameron <jic23@cam.ac.uk>2011-09-29 20:50:04 +0400
committerGuenter Roeck <guenter.roeck@ericsson.com>2011-10-24 22:09:41 +0400
commit4f3a659581cabf1be441d6467b523be914615496 (patch)
tree7d5d581f10409b883fab255f7ccede8692497b2b /drivers/hwmon/ad7314.c
parent200855e52db1b1834121ba57fbd89c5b4911e02c (diff)
downloadlinux-4f3a659581cabf1be441d6467b523be914615496.tar.xz
hwmon: AD7314 driver (ported from IIO)
Driver for AD7314, ADT7301, and ADT7302, ported from IIO. Currently dropped power down mode support. Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> [guenter.roeck@ericsson.com: Added MODULE_DEVICE_TABLE] Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Diffstat (limited to 'drivers/hwmon/ad7314.c')
-rw-r--r--drivers/hwmon/ad7314.c186
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/hwmon/ad7314.c b/drivers/hwmon/ad7314.c
new file mode 100644
index 000000000000..318e38e85376
--- /dev/null
+++ b/drivers/hwmon/ad7314.c
@@ -0,0 +1,186 @@
+/*
+ * 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>
+
+/*
+ * AD7314 power mode
+ */
+#define AD7314_PD 0x2000
+
+/*
+ * AD7314 temperature masks
+ */
+#define AD7314_TEMP_SIGN 0x200
+#define AD7314_TEMP_MASK 0x7FE0
+#define AD7314_TEMP_OFFSET 5
+
+/*
+ * ADT7301 and ADT7302 temperature masks
+ */
+#define ADT7301_TEMP_SIGN 0x2000
+#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, s16 *data)
+{
+ 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;
+ }
+
+ *data = be16_to_cpu(chip->rx);
+
+ return ret;
+}
+
+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, &data);
+ if (ret < 0)
+ return ret;
+ switch (spi_get_device_id(chip->spi_dev)->driver_data) {
+ case ad7314:
+ data = (data & AD7314_TEMP_MASK) >> AD7314_TEMP_OFFSET;
+ data = (data << 6) >> 6;
+
+ 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 &= ADT7301_TEMP_MASK;
+ data = (data << 2) >> 2;
+
+ return sprintf(buf, "%d\n",
+ DIV_ROUND_CLOSEST(data * 3125, 100));
+ default:
+ return -EINVAL;
+ }
+}
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
+ ad7314_show_temperature, NULL, 0);
+
+static struct attribute *ad7314_attributes[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7314_group = {
+ .attrs = ad7314_attributes,
+};
+
+static int __devinit ad7314_probe(struct spi_device *spi_dev)
+{
+ int ret;
+ struct ad7314_data *chip;
+
+ chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+ if (chip == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ dev_set_drvdata(&spi_dev->dev, chip);
+
+ ret = sysfs_create_group(&spi_dev->dev.kobj, &ad7314_group);
+ if (ret < 0)
+ goto error_free_chip;
+ 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;
+ }
+
+ return 0;
+error_remove_group:
+ sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
+error_free_chip:
+ kfree(chip);
+error_ret:
+ return ret;
+}
+
+static int __devexit ad7314_remove(struct spi_device *spi_dev)
+{
+ struct ad7314_data *chip = dev_get_drvdata(&spi_dev->dev);
+
+ hwmon_device_unregister(chip->hwmon_dev);
+ sysfs_remove_group(&spi_dev->dev.kobj, &ad7314_group);
+ kfree(chip);
+
+ 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",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7314_probe,
+ .remove = __devexit_p(ad7314_remove),
+ .id_table = ad7314_id,
+};
+
+static __init int ad7314_init(void)
+{
+ return spi_register_driver(&ad7314_driver);
+}
+module_init(ad7314_init);
+
+static __exit void ad7314_exit(void)
+{
+ spi_unregister_driver(&ad7314_driver);
+}
+module_exit(ad7314_exit);
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7314, ADT7301 and ADT7302 digital"
+ " temperature sensor driver");
+MODULE_LICENSE("GPL v2");