1 files changed, 501 insertions, 0 deletions

diff --git a/drivers/staging/iio/adc/ad7298.c b/drivers/staging/iio/adc/ad7298.c
new file mode 100644
index 00000000000..1a080c97763
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7298.c
@@ -0,0 +1,501 @@
+/*
+ * 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);