--- /dev/null
+/*
+ * AD7298 digital temperature sensor driver supporting AD7298
+ *
+ * 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/slab.h>
+#include <linux/sysfs.h>
+#include <linux/list.h>
+#include <linux/spi/spi.h>
+#include <linux/rtc.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+/*
+ * AD7298 command
+ */
+#define AD7298_PD 0x1
+#define AD7298_T_AVG_MASK 0x2
+#define AD7298_EXT_REF 0x4
+#define AD7298_T_SENSE_MASK 0x20
+#define AD7298_VOLTAGE_MASK 0x3fc0
+#define AD7298_VOLTAGE_OFFSET 0x6
+#define AD7298_VOLTAGE_LIMIT_COUNT 8
+#define AD7298_REPEAT 0x40
+#define AD7298_WRITE 0x80
+
+/*
+ * AD7298 value masks
+ */
+#define AD7298_CHANNEL_MASK 0xf000
+#define AD7298_VALUE_MASK 0xfff
+#define AD7298_T_VALUE_SIGN 0x400
+#define AD7298_T_VALUE_FLOAT_OFFSET 2
+#define AD7298_T_VALUE_FLOAT_MASK 0x2
+
+/*
+ * struct ad7298_chip_info - chip specifc information
+ */
+
+struct ad7298_chip_info {
+ const char *name;
+ struct spi_device *spi_dev;
+ struct iio_dev *indio_dev;
+ u16 command;
+ u16 busy_pin;
+ u8 channels; /* Active voltage channels */
+};
+
+/*
+ * ad7298 register access by SPI
+ */
+static int ad7298_spi_write(struct ad7298_chip_info *chip, u16 data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret = 0;
+
+ data |= AD7298_WRITE;
+ data = cpu_to_be16(data);
+ ret = spi_write(spi_dev, (u8 *)&data, sizeof(data));
+ if (ret < 0)
+ dev_err(&spi_dev->dev, "SPI write error\n");
+
+ return ret;
+}
+
+static int ad7298_spi_read(struct ad7298_chip_info *chip, u16 mask, u16 *data)
+{
+ struct spi_device *spi_dev = chip->spi_dev;
+ int ret = 0;
+ u8 count = chip->channels;
+ u16 command;
+ int i;
+
+ if (mask & AD7298_T_SENSE_MASK) {
+ command = chip->command & ~(AD7298_T_AVG_MASK | AD7298_VOLTAGE_MASK);
+ command |= AD7298_T_SENSE_MASK;
+ count = 1;
+ } else if (mask & AD7298_T_AVG_MASK) {
+ command = chip->command & ~AD7298_VOLTAGE_MASK;
+ command |= AD7298_T_SENSE_MASK | AD7298_T_AVG_MASK;
+ count = 2;
+ } else if (mask & AD7298_VOLTAGE_MASK) {
+ command = chip->command & ~(AD7298_T_AVG_MASK | AD7298_T_SENSE_MASK);
+ count = chip->channels;
+ }
+
+ ret = ad7298_spi_write(chip, chip->command);
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI write command error\n");
+ return ret;
+ }
+
+ ret = spi_read(spi_dev, (u8 *)&command, sizeof(command));
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI read error\n");
+ return ret;
+ }
+
+ i = 10000;
+ while (i && gpio_get_value(chip->busy_pin)) {
+ cpu_relax();
+ i--;
+ }
+ if (!i) {
+ dev_err(&spi_dev->dev, "Always in busy convertion.\n");
+ return -EBUSY;
+ }
+
+ for (i = 0; i < count; i++) {
+ ret = spi_read(spi_dev, (u8 *)&data[i], sizeof(data[i]));
+ if (ret < 0) {
+ dev_err(&spi_dev->dev, "SPI read error\n");
+ return ret;
+ }
+ *data = be16_to_cpu(data[i]);
+ }
+
+ return 0;
+}
+
+static ssize_t ad7298_show_mode(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+
+ if (chip->command & AD7298_REPEAT)
+ return sprintf(buf, "repeat\n");
+ else
+ return sprintf(buf, "normal\n");
+}
+
+static ssize_t ad7298_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 ad7298_chip_info *chip = dev_info->dev_data;
+
+ if (strcmp(buf, "repeat"))
+ chip->command |= AD7298_REPEAT;
+ else
+ chip->command &= (~AD7298_REPEAT);
+
+ return 1;
+}
+
+static IIO_DEVICE_ATTR(mode, S_IRUGO | S_IWUSR,
+ ad7298_show_mode,
+ ad7298_store_mode,
+ 0);
+
+static ssize_t ad7298_show_available_modes(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "normal\nrepeat\n");
+}
+
+static IIO_DEVICE_ATTR(available_modes, S_IRUGO, ad7298_show_available_modes, NULL, 0);
+
+static ssize_t ad7298_store_reset(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ u16 command;
+ int ret;
+
+ command = chip->command & ~AD7298_PD;
+
+ ret = ad7298_spi_write(chip, command);
+ if (ret)
+ return -EIO;
+
+ command = chip->command | AD7298_PD;
+
+ ret = ad7298_spi_write(chip, command);
+ if (ret)
+ return -EIO;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(reset, S_IWUSR,
+ NULL,
+ ad7298_store_reset,
+ 0);
+
+static ssize_t ad7298_show_ext_ref(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+
+ return sprintf(buf, "%d\n", !!(chip->command & AD7298_EXT_REF));
+}
+
+static ssize_t ad7298_store_ext_ref(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ u16 command;
+ int ret;
+
+ command = chip->command & (~AD7298_EXT_REF);
+ if (strcmp(buf, "1"))
+ command |= AD7298_EXT_REF;
+
+ ret = ad7298_spi_write(chip, command);
+ if (ret)
+ return -EIO;
+
+ chip->command = command;
+
+ return len;
+}
+
+static IIO_DEVICE_ATTR(ext_ref, S_IRUGO | S_IWUSR,
+ ad7298_show_ext_ref,
+ ad7298_store_ext_ref,
+ 0);
+
+static ssize_t ad7298_show_t_sense(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ u16 data;
+ char sign = ' ';
+ int ret;
+
+ ret = ad7298_spi_read(chip, AD7298_T_SENSE_MASK, &data);
+ if (ret)
+ return -EIO;
+
+ if (data & AD7298_T_VALUE_SIGN) {
+ /* convert supplement to positive value */
+ data = (AD7298_T_VALUE_SIGN << 1) - data;
+ sign = '-';
+ }
+
+ return sprintf(buf, "%c%d.%.2d\n", sign,
+ (data >> AD7298_T_VALUE_FLOAT_OFFSET),
+ (data & AD7298_T_VALUE_FLOAT_MASK) * 25);
+}
+
+static IIO_DEVICE_ATTR(t_sense, S_IRUGO, ad7298_show_t_sense, NULL, 0);
+
+static ssize_t ad7298_show_t_average(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ u16 data[2];
+ char sign = ' ';
+ int ret;
+
+ ret = ad7298_spi_read(chip, AD7298_T_AVG_MASK, data);
+ if (ret)
+ return -EIO;
+
+ if (data[1] & AD7298_T_VALUE_SIGN) {
+ /* convert supplement to positive value */
+ data[1] = (AD7298_T_VALUE_SIGN << 1) - data[1];
+ sign = '-';
+ }
+
+ return sprintf(buf, "%c%d.%.2d\n", sign,
+ (data[1] >> AD7298_T_VALUE_FLOAT_OFFSET),
+ (data[1] & AD7298_T_VALUE_FLOAT_MASK) * 25);
+}
+
+static IIO_DEVICE_ATTR(t_average, S_IRUGO, ad7298_show_t_average, NULL, 0);
+
+static ssize_t ad7298_show_voltage(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ u16 data[AD7298_VOLTAGE_LIMIT_COUNT];
+ int i, size, ret;
+
+ ret = ad7298_spi_read(chip, AD7298_VOLTAGE_MASK, data);
+ if (ret)
+ return -EIO;
+
+ for (i = 0; i < AD7298_VOLTAGE_LIMIT_COUNT; i++) {
+ if (chip->command & (AD7298_T_SENSE_MASK << i)) {
+ ret = sprintf(buf, "channel[%d]=%d\n", i,
+ data[i] & AD7298_VALUE_MASK);
+ if (ret < 0)
+ break;
+ buf += ret;
+ size += ret;
+ }
+ }
+
+ return size;
+}
+
+static IIO_DEVICE_ATTR(voltage, S_IRUGO, ad7298_show_voltage, NULL, 0);
+
+static ssize_t ad7298_show_channel_mask(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+
+ return sprintf(buf, "0x%x\n", (chip->command & AD7298_VOLTAGE_MASK) >>
+ AD7298_VOLTAGE_OFFSET);
+}
+
+static ssize_t ad7298_store_channel_mask(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ unsigned long data;
+ int i, ret;
+
+ ret = strict_strtoul(buf, 16, &data);
+ if (ret || data > 0xff)
+ return -EINVAL;
+
+ chip->command &= (~AD7298_VOLTAGE_MASK);
+ chip->command |= data << AD7298_VOLTAGE_OFFSET;
+
+ for (i = 0, chip->channels = 0; i < AD7298_VOLTAGE_LIMIT_COUNT; i++) {
+ if (chip->command & (AD7298_T_SENSE_MASK << i))
+ chip->channels++;
+ }
+
+ return ret;
+}
+
+static IIO_DEVICE_ATTR(channel_mask, S_IRUGO | S_IWUSR,
+ ad7298_show_channel_mask,
+ ad7298_store_channel_mask,
+ 0);
+
+static ssize_t ad7298_show_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *dev_info = dev_get_drvdata(dev);
+ struct ad7298_chip_info *chip = dev_info->dev_data;
+ return sprintf(buf, "%s\n", chip->name);
+}
+
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad7298_show_name, NULL, 0);
+
+static struct attribute *ad7298_attributes[] = {
+ &iio_dev_attr_available_modes.dev_attr.attr,
+ &iio_dev_attr_mode.dev_attr.attr,
+ &iio_dev_attr_reset.dev_attr.attr,
+ &iio_dev_attr_ext_ref.dev_attr.attr,
+ &iio_dev_attr_t_sense.dev_attr.attr,
+ &iio_dev_attr_t_average.dev_attr.attr,
+ &iio_dev_attr_voltage.dev_attr.attr,
+ &iio_dev_attr_channel_mask.dev_attr.attr,
+ &iio_dev_attr_name.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad7298_attribute_group = {
+ .attrs = ad7298_attributes,
+};
+
+/*
+ * device probe and remove
+ */
+static int __devinit ad7298_probe(struct spi_device *spi_dev)
+{
+ struct ad7298_chip_info *chip;
+ unsigned short *pins = spi_dev->dev.platform_data;
+ int ret = 0;
+
+ chip = kzalloc(sizeof(struct ad7298_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->busy_pin = pins[0];
+
+ ret = gpio_request(chip->busy_pin, chip->name);
+ if (ret) {
+ dev_err(&spi_dev->dev, "Fail to request busy gpio PIN %d.\n",
+ chip->busy_pin);
+ goto error_free_chip;
+ }
+ gpio_direction_input(chip->busy_pin);
+
+ chip->indio_dev = iio_allocate_device();
+ if (chip->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_free_gpio;
+ }
+
+ chip->indio_dev->dev.parent = &spi_dev->dev;
+ chip->indio_dev->attrs = &ad7298_attribute_group;
+ chip->indio_dev->dev_data = (void *)chip;
+ chip->indio_dev->driver_module = THIS_MODULE;
+ chip->indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = iio_device_register(chip->indio_dev);
+ if (ret)
+ goto error_free_dev;
+
+ dev_info(&spi_dev->dev, "%s temperature sensor and ADC registered.\n",
+ chip->name);
+
+ return 0;
+
+error_free_dev:
+ iio_free_device(chip->indio_dev);
+error_free_gpio:
+ gpio_free(chip->busy_pin);
+error_free_chip:
+ kfree(chip);
+
+ return ret;
+}
+
+static int __devexit ad7298_remove(struct spi_device *spi_dev)
+{
+ struct ad7298_chip_info *chip = dev_get_drvdata(&spi_dev->dev);
+ struct iio_dev *indio_dev = chip->indio_dev;
+
+ dev_set_drvdata(&spi_dev->dev, NULL);
+ iio_device_unregister(indio_dev);
+ iio_free_device(chip->indio_dev);
+ gpio_free(chip->busy_pin);
+ kfree(chip);
+
+ return 0;
+}
+
+static const struct spi_device_id ad7298_id[] = {
+ { "ad7298", 0 },
+ {}
+};
+
+MODULE_DEVICE_TABLE(spi, ad7298_id);
+
+static struct spi_driver ad7298_driver = {
+ .driver = {
+ .name = "ad7298",
+ .bus = &spi_bus_type,
+ .owner = THIS_MODULE,
+ },
+ .probe = ad7298_probe,
+ .remove = __devexit_p(ad7298_remove),
+ .id_table = ad7298_id,
+};
+
+static __init int ad7298_init(void)
+{
+ return spi_register_driver(&ad7298_driver);
+}
+
+static __exit void ad7298_exit(void)
+{
+ spi_unregister_driver(&ad7298_driver);
+}
+
+MODULE_AUTHOR("Sonic Zhang <sonic.zhang@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7298 digital"
+ " temperature sensor and ADC driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(ad7298_init);
+module_exit(ad7298_exit);
projects / mv-sheeva.git / blobdiff