Added: trunk/drivers/staging/iio/adc/ad7314.c (0 => 8577)
--- trunk/drivers/staging/iio/adc/ad7314.c (rev 0)
+++ trunk/drivers/staging/iio/adc/ad7314.c 2010-03-30 09:51:00 UTC (rev 8577)
@@ -0,0 +1,280 @@
+/*
+ * AD7314 digital temperature sensor driver
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+#include <linux/rtc.h>
+
+#include "../iio.h"
+#include "../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
+#define AD7314_TEMP_FLOAT_OFFSET 2
+#define AD7314_TEMP_FLOAT_MASK 0x3
+
+/*
+ * struct ad7314_chip_info - chip specifc information
+ */
+
+struct ad7314_chip_info {
+ const char *name;
+ struct spi_device *spi_dev;
+ struct iio_dev *indio_dev;
+ struct iio_work_cont work_cont_thresh;
+ s64 last_timestamp;
+ u8 mode;
+};
+
+/*
+ * ad7314 register access by SPI
+ */
+
+static int ad7314_spi_read(struct ad7314_chip_info *chip, u16 *data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret = 0;
+ u16 value;
+
+ ret = spi_read(spi_dev, (u8 *)&value, sizeof(value));
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI read error\n");
+ return ret;
+ }
+
+ *data = ""
+
+ return ret;
+}
+
+static int ad7314_spi_write(struct ad7314_chip_info *chip, u16 data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret = 0;
+ u16 value = cpu_to_be16(data);
+
+ ret = spi_write(spi_dev, (u8 *)&value, sizeof(value));
+ if (ret < 0)
+ dev_err(&spi_dev->dev, "SPI write error\n");
+
+ return ret;
+}
+
+static ssize_t ad7314_show_mode(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7314_chip_info *chip = dev_info->dev_data;
+
+ if (chip->mode)
+ return sprintf(buf, "power-save\n");
+ else
+ return sprintf(buf, "full\n");
+}
+
+static ssize_t ad7314_store_mode(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7314_chip_info *chip = dev_info->dev_data;
+ u16 mode = 0;
+ int ret;
+
+ if (!strcmp(buf, "full"))
+ mode = AD7314_PD;
+
+ ret = ad7314_spi_write(chip, mode);
+ if (ret)
+ return -EIO;
+
+ chip->mode = mode;
+
+ return ret;
+}
+
+IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
+ ad7314_show_mode,
+ ad7314_store_mode,
+ 0);
+
+static ssize_t ad7314_show_available_modes(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "full\npower-save\n");
+}
+
+IIO_DEVICE_ATTR(available_modes, S_IRUGO, ad7314_show_available_modes, NULL, 0);
+
+static ssize_t ad7314_show_temperature(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7314_chip_info *chip = dev_info->dev_data;
+ u16 data;
+ char sign = ' ';
+ int ret;
+
+ if (chip->mode) {
+ ret = ad7314_spi_write(chip, 0);
+ if (ret)
+ return -EIO;
+ }
+
+ ret = ad7314_spi_read(chip, &data);
+ if (ret)
+ return -EIO;
+
+ if (chip->mode)
+ ad7314_spi_write(chip, chip->mode);
+
+ data = "" & AD7314_TEMP_MASK) >>
+ AD7314_TEMP_OFFSET;
+ if (data & AD7314_TEMP_SIGN) {
+ data = "" << 1) - data;
+ sign = '-';
+ }
+
+ return sprintf(buf, "%c%d.%.2d\n", sign,
+ data >> AD7314_TEMP_FLOAT_OFFSET,
+ (data & AD7314_TEMP_FLOAT_MASK) * 25);
+}
+
+IIO_DEVICE_ATTR(temperature, S_IRUGO, ad7314_show_temperature, NULL, 0);
+
+static ssize_t ad7314_show_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7314_chip_info *chip = dev_info->dev_data;
+ return sprintf(buf, "%s\n", chip->name);
+}
+
+IIO_DEVICE_ATTR(name, S_IRUGO, ad7314_show_name, NULL, 0);
+
+static struct attribute *ad7314_attributes[] = {
+ &iio_dev_attr_available_modes.dev_attr.attr,
+ &iio_dev_attr_mode.dev_attr.attr,
+ &iio_dev_attr_temperature.dev_attr.attr,
+ &iio_dev_attr_name.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7314_attribute_group = {
+ .attrs = ad7314_attributes,
+};
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit ad7314_probe(struct spi_device *spi_dev)
+{
+ struct ad7314_chip_info *chip;
+ int ret = 0;
+
+ chip = kzalloc(sizeof(struct ad7314_chip_info), GFP_KERNEL);
+
+ if (chip == NULL)
+ return -ENOMEM;
+
+ /* this is only used for device removal purposes */
+ dev_set_drvdata(&spi_dev->dev, chip);
+
+ chip->spi_dev = spi_dev;
+ chip->name = spi_dev->modalias;
+
+ chip->indio_dev = iio_allocate_device();
+ if (chip->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_free_chip;
+ }
+
+ chip->indio_dev->dev.parent = &spi_dev->dev;
+ chip->indio_dev->attrs = &ad7314_attribute_group;
+ chip->indio_dev->dev_data = (void *)chip;
+ chip->indio_dev->driver_module = THIS_MODULE;
+
+ ret = iio_device_register(chip->indio_dev);
+ if (ret)
+ goto error_free_dev;
+
+ dev_info(&spi_dev->dev, "%s temperature sensor registered.\n",
+ chip->name);
+
+ return 0;
+error_free_dev:
+ iio_free_device(chip->indio_dev);
+error_free_chip:
+ kfree(chip);
+
+ return ret;
+}
+
+static int __devexit ad7314_remove(struct spi_device *spi_dev)
+{
+ struct ad7314_chip_info *chip = dev_get_drvdata(&spi_dev->dev);
+ struct iio_dev *indio_dev = chip->indio_dev;
+
+ dev_set_drvdata(&spi_dev->dev, NULL);
+ if (spi_dev->irq)
+ iio_unregister_interrupt_line(indio_dev, 0);
+ iio_device_unregister(indio_dev);
+ iio_free_device(chip->indio_dev);
+ kfree(chip);
+
+ return 0;
+}
+
+static struct spi_driver ad7314_driver = {
+ .driver = {
+ .name = "ad7314",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7314_probe,
+ .remove = __devexit_p(ad7314_remove),
+};
+
+static __init int ad7314_init(void)
+{
+ return spi_register_driver(&ad7314_driver);
+}
+
+static __exit void ad7314_exit(void)
+{
+ spi_unregister_driver(&ad7314_driver);
+}
+
+MODULE_AUTHOR("Sonic Zhang <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD7314 digital"
+ " temperature sensor driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(ad7314_init);
+module_exit(ad7314_exit);
