[PATCH 08/36] staging: iio: adc: new driver for AD7150/1/6 devices

[Mike Frysinger <vapier@gentoo.org>]

From: Barry Song <barry.song@analog.com>

Signed-off-by: Barry Song <barry.song@analog.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
---
 drivers/staging/iio/adc/Kconfig  |    7 +
 drivers/staging/iio/adc/Makefile |    2 +
 drivers/staging/iio/adc/ad7150.c |  877 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 886 insertions(+), 0 deletions(-)
 create mode 100644 drivers/staging/iio/adc/ad7150.c

diff --git a/drivers/staging/iio/adc/Kconfig b/drivers/staging/iio/adc/Kconfig
index acb6767..51b9cc6 100644
--- a/drivers/staging/iio/adc/Kconfig
+++ b/drivers/staging/iio/adc/Kconfig
@@ -27,6 +27,13 @@ config MAX1363_RING_BUFFER
 	  Say yes here to include ring buffer support in the MAX1363
 	  ADC driver.
 
+config AD7150
+	tristate "Analog Devices ad7150/1/6 capacitive sensor driver"
+	depends on I2C
+	help
+	  Say yes here to build support for Analog Devices capacitive sensors.
+	  (ad7150, ad7151, ad7156) Provides direct access via sysfs.
+
 config AD799X
 	tristate "Analog Devices AD799x ADC driver"
 	depends on I2C
diff --git a/drivers/staging/iio/adc/Makefile b/drivers/staging/iio/adc/Makefile
index b62c319b..51b39aa 100644
--- a/drivers/staging/iio/adc/Makefile
+++ b/drivers/staging/iio/adc/Makefile
@@ -14,3 +14,5 @@ obj-$(CONFIG_AD799X) += ad799x.o
 ad7476-y := ad7476_core.o
 ad7476-$(CONFIG_IIO_RING_BUFFER) += ad7476_ring.o
 obj-$(CONFIG_AD7476) += ad7476.o
+
+obj-$(CONFIG_AD7150) += ad7150.o
diff --git a/drivers/staging/iio/adc/ad7150.c b/drivers/staging/iio/adc/ad7150.c
new file mode 100644
index 0000000..8555766
--- /dev/null
+++ b/drivers/staging/iio/adc/ad7150.c
@@ -0,0 +1,877 @@
+/*
+ * AD7150 capacitive sensor driver supporting AD7150/1/6
+ *
+ * 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/i2c.h>
+#include <linux/rtc.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+
+/*
+ * AD7150 registers definition
+ */
+
+#define AD7150_STATUS              0
+#define AD7150_STATUS_OUT1         (1 << 3)
+#define AD7150_STATUS_OUT2         (1 << 5)
+#define AD7150_CH1_DATA_HIGH       1
+#define AD7150_CH1_DATA_LOW        2
+#define AD7150_CH2_DATA_HIGH       3
+#define AD7150_CH2_DATA_LOW        4
+#define AD7150_CH1_AVG_HIGH        5
+#define AD7150_CH1_AVG_LOW         6
+#define AD7150_CH2_AVG_HIGH        7
+#define AD7150_CH2_AVG_LOW         8
+#define AD7150_CH1_SENSITIVITY     9
+#define AD7150_CH1_THR_HOLD_H      9
+#define AD7150_CH1_TIMEOUT         10
+#define AD7150_CH1_THR_HOLD_L      10
+#define AD7150_CH1_SETUP           11
+#define AD7150_CH2_SENSITIVITY     12
+#define AD7150_CH2_THR_HOLD_H      12
+#define AD7150_CH2_TIMEOUT         13
+#define AD7150_CH2_THR_HOLD_L      13
+#define AD7150_CH2_SETUP           14
+#define AD7150_CFG                 15
+#define AD7150_CFG_FIX             (1 << 7)
+#define AD7150_PD_TIMER            16
+#define AD7150_CH1_CAPDAC          17
+#define AD7150_CH2_CAPDAC          18
+#define AD7150_SN3                 19
+#define AD7150_SN2                 20
+#define AD7150_SN1                 21
+#define AD7150_SN0                 22
+#define AD7150_ID                  23
+
+#define AD7150_MAX_CONV_MODE       4
+
+/*
+ * struct ad7150_chip_info - chip specifc information
+ */
+
+struct ad7150_chip_info {
+	const char *name;
+	struct i2c_client *client;
+	struct iio_dev *indio_dev;
+	struct work_struct thresh_work;
+	bool inter;
+	s64 last_timestamp;
+	u16 ch1_threshold;     /* Ch1 Threshold (in fixed threshold mode) */
+	u8  ch1_sensitivity;   /* Ch1 Sensitivity (in adaptive threshold mode) */
+	u8  ch1_timeout;       /* Ch1 Timeout (in adaptive threshold mode) */
+	u8  ch1_setup;
+	u16 ch2_threshold;     /* Ch2 Threshold (in fixed threshold mode) */
+	u8  ch2_sensitivity;   /* Ch1 Sensitivity (in adaptive threshold mode) */
+	u8  ch2_timeout;       /* Ch1 Timeout (in adaptive threshold mode) */
+	u8  ch2_setup;
+	u8  powerdown_timer;
+	char threshold_mode[10]; /* adaptive/fixed threshold mode */
+	int old_state;
+	char *conversion_mode;
+};
+
+struct ad7150_conversion_mode {
+	char *name;
+	u8 reg_cfg;
+};
+
+struct ad7150_conversion_mode ad7150_conv_mode_table[AD7150_MAX_CONV_MODE] = {
+	{ "idle", 0 },
+	{ "continuous-conversion", 1 },
+	{ "single-conversion", 2 },
+	{ "power-down", 3 },
+};
+
+/*
+ * ad7150 register access by I2C
+ */
+
+static int ad7150_i2c_read(struct ad7150_chip_info *chip, u8 reg, u8 *data, int len)
+{
+	struct i2c_client *client = chip->client;
+	int ret = 0;
+
+	ret = i2c_master_send(client, &reg, 1);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C write error\n");
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, data, len);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C read error\n");
+		return ret;
+	}
+
+	return ret;
+}
+
+static int ad7150_i2c_write(struct ad7150_chip_info *chip, u8 reg, u8 data)
+{
+	struct i2c_client *client = chip->client;
+	int ret = 0;
+
+	u8 tx[2] = {
+		reg,
+		data,
+	};
+
+	ret = i2c_master_send(client, tx, 2);
+	if (ret < 0)
+		dev_err(&client->dev, "I2C write error\n");
+
+	return ret;
+}
+
+/*
+ * sysfs nodes
+ */
+
+#define IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(_show)				\
+	IIO_DEVICE_ATTR(available_conversion_modes, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_CONVERSION_MODE(_mode, _show, _store)              \
+	IIO_DEVICE_ATTR(conversion_mode, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_AVAIL_THRESHOLD_MODES(_show)				\
+	IIO_DEVICE_ATTR(available_threshold_modes, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_THRESHOLD_MODE(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(threshold_mode, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH1_THRESHOLD(_mode, _show, _store)              \
+	IIO_DEVICE_ATTR(ch1_threshold, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH2_THRESHOLD(_mode, _show, _store)              \
+	IIO_DEVICE_ATTR(ch2_threshold, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH1_SENSITIVITY(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(ch1_sensitivity, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH2_SENSITIVITY(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(ch2_sensitivity, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH1_TIMEOUT(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(ch1_timeout, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH2_TIMEOUT(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(ch2_timeout, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH1_VALUE(_show)		\
+	IIO_DEVICE_ATTR(ch1_value, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_CH2_VALUE(_show)		\
+	IIO_DEVICE_ATTR(ch2_value, S_IRUGO, _show, NULL, 0)
+#define IIO_DEV_ATTR_CH1_SETUP(_mode, _show, _store)		\
+	IIO_DEVICE_ATTR(ch1_setup, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_CH2_SETUP(_mode, _show, _store)              \
+	IIO_DEVICE_ATTR(ch2_setup, _mode, _show, _store, 0)
+#define IIO_DEV_ATTR_POWERDOWN_TIMER(_mode, _show, _store)              \
+	IIO_DEVICE_ATTR(powerdown_timer, _mode, _show, _store, 0)
+
+static ssize_t ad7150_show_conversion_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	int i;
+	int len = 0;
+
+	for (i = 0; i < AD7150_MAX_CONV_MODE; i++)
+		len += sprintf(buf + len, "%s\n", ad7150_conv_mode_table[i].name);
+
+	return len;
+}
+
+static IIO_DEV_ATTR_AVAIL_CONVERSION_MODES(ad7150_show_conversion_modes);
+
+static ssize_t ad7150_show_conversion_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%s\n", chip->conversion_mode);
+}
+
+static ssize_t ad7150_store_conversion_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	u8 cfg;
+	int i;
+
+	ad7150_i2c_read(chip, AD7150_CFG, &cfg, 1);
+
+	for (i = 0; i < AD7150_MAX_CONV_MODE; i++) {
+		if (strncmp(buf, ad7150_conv_mode_table[i].name,
+				strlen(ad7150_conv_mode_table[i].name) - 1) == 0) {
+			chip->conversion_mode = ad7150_conv_mode_table[i].name;
+			cfg |= 0x18 | ad7150_conv_mode_table[i].reg_cfg;
+			ad7150_i2c_write(chip, AD7150_CFG, cfg);
+			return len;
+		}
+	}
+
+	dev_err(dev, "not supported conversion mode\n");
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CONVERSION_MODE(S_IRUGO | S_IWUSR,
+		ad7150_show_conversion_mode,
+		ad7150_store_conversion_mode);
+
+static ssize_t ad7150_show_threshold_modes(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	return sprintf(buf, "adaptive\nfixed\n");
+}
+
+static IIO_DEV_ATTR_AVAIL_THRESHOLD_MODES(ad7150_show_threshold_modes);
+
+static ssize_t ad7150_show_ch1_value(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	u8 data[2];
+
+	ad7150_i2c_read(chip, AD7150_CH1_DATA_HIGH, data, 2);
+	return sprintf(buf, "%d\n", ((int) data[0] << 8) | data[1]);
+}
+
+static IIO_DEV_ATTR_CH1_VALUE(ad7150_show_ch1_value);
+
+static ssize_t ad7150_show_ch2_value(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	u8 data[2];
+
+	ad7150_i2c_read(chip, AD7150_CH2_DATA_HIGH, data, 2);
+	return sprintf(buf, "%d\n", ((int) data[0] << 8) | data[1]);
+}
+
+static IIO_DEV_ATTR_CH2_VALUE(ad7150_show_ch2_value);
+
+static ssize_t ad7150_show_threshold_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%s\n", chip->threshold_mode);
+}
+
+static ssize_t ad7150_store_threshold_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	u8 cfg;
+
+	ad7150_i2c_read(chip, AD7150_CFG, &cfg, 1);
+
+	if (strncmp(buf, "fixed", 5) == 0) {
+		strcpy(chip->threshold_mode, "fixed");
+		cfg |= AD7150_CFG_FIX;
+		ad7150_i2c_write(chip, AD7150_CFG, cfg);
+
+		return len;
+	} else if (strncmp(buf, "adaptive", 8) == 0) {
+		strcpy(chip->threshold_mode, "adaptive");
+		cfg &= ~AD7150_CFG_FIX;
+		ad7150_i2c_write(chip, AD7150_CFG, cfg);
+
+		return len;
+	}
+
+	dev_err(dev, "not supported threshold mode\n");
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_THRESHOLD_MODE(S_IRUGO | S_IWUSR,
+		ad7150_show_threshold_mode,
+		ad7150_store_threshold_mode);
+
+static ssize_t ad7150_show_ch1_threshold(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch1_threshold);
+}
+
+static ssize_t ad7150_store_ch1_threshold(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x10000)) {
+		ad7150_i2c_write(chip, AD7150_CH1_THR_HOLD_H, data >> 8);
+		ad7150_i2c_write(chip, AD7150_CH1_THR_HOLD_L, data);
+		chip->ch1_threshold = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH1_THRESHOLD(S_IRUGO | S_IWUSR,
+		ad7150_show_ch1_threshold,
+		ad7150_store_ch1_threshold);
+
+static ssize_t ad7150_show_ch2_threshold(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch2_threshold);
+}
+
+static ssize_t ad7150_store_ch2_threshold(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x10000)) {
+		ad7150_i2c_write(chip, AD7150_CH2_THR_HOLD_H, data >> 8);
+		ad7150_i2c_write(chip, AD7150_CH2_THR_HOLD_L, data);
+		chip->ch2_threshold = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH2_THRESHOLD(S_IRUGO | S_IWUSR,
+		ad7150_show_ch2_threshold,
+		ad7150_store_ch2_threshold);
+
+static ssize_t ad7150_show_ch1_sensitivity(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch1_sensitivity);
+}
+
+static ssize_t ad7150_store_ch1_sensitivity(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH1_SENSITIVITY, data);
+		chip->ch1_sensitivity = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH1_SENSITIVITY(S_IRUGO | S_IWUSR,
+		ad7150_show_ch1_sensitivity,
+		ad7150_store_ch1_sensitivity);
+
+static ssize_t ad7150_show_ch2_sensitivity(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch2_sensitivity);
+}
+
+static ssize_t ad7150_store_ch2_sensitivity(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH2_SENSITIVITY, data);
+		chip->ch2_sensitivity = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH2_SENSITIVITY(S_IRUGO | S_IWUSR,
+		ad7150_show_ch2_sensitivity,
+		ad7150_store_ch2_sensitivity);
+
+static ssize_t ad7150_show_ch1_timeout(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch1_timeout);
+}
+
+static ssize_t ad7150_store_ch1_timeout(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH1_TIMEOUT, data);
+		chip->ch1_timeout = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH1_TIMEOUT(S_IRUGO | S_IWUSR,
+		ad7150_show_ch1_timeout,
+		ad7150_store_ch1_timeout);
+
+static ssize_t ad7150_show_ch2_timeout(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "%d\n", chip->ch2_timeout);
+}
+
+static ssize_t ad7150_store_ch2_timeout(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH2_TIMEOUT, data);
+		chip->ch2_timeout = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH2_TIMEOUT(S_IRUGO | S_IWUSR,
+		ad7150_show_ch2_timeout,
+		ad7150_store_ch2_timeout);
+
+static ssize_t ad7150_show_ch1_setup(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "0x%02x\n", chip->ch1_setup);
+}
+
+static ssize_t ad7150_store_ch1_setup(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH1_SETUP, data);
+		chip->ch1_setup = data;
+		return len;
+	}
+
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH1_SETUP(S_IRUGO | S_IWUSR,
+		ad7150_show_ch1_setup,
+		ad7150_store_ch1_setup);
+
+static ssize_t ad7150_show_ch2_setup(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "0x%02x\n", chip->ch2_setup);
+}
+
+static ssize_t ad7150_store_ch2_setup(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x100)) {
+		ad7150_i2c_write(chip, AD7150_CH2_SETUP, data);
+		chip->ch2_setup = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_CH2_SETUP(S_IRUGO | S_IWUSR,
+		ad7150_show_ch2_setup,
+		ad7150_store_ch2_setup);
+
+static ssize_t ad7150_show_name(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	return sprintf(buf, "%s\n", chip->name);
+}
+
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad7150_show_name, NULL, 0);
+
+static ssize_t ad7150_show_powerdown_timer(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	return sprintf(buf, "0x%02x\n", chip->powerdown_timer);
+}
+
+static ssize_t ad7150_store_powerdown_timer(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+	unsigned long data;
+	int ret;
+
+	ret = strict_strtoul(buf, 10, &data);
+
+	if ((!ret) && (data < 0x40)) {
+		chip->powerdown_timer = data;
+		return len;
+	}
+
+	return -EINVAL;
+}
+
+static IIO_DEV_ATTR_POWERDOWN_TIMER(S_IRUGO | S_IWUSR,
+		ad7150_show_powerdown_timer,
+		ad7150_store_powerdown_timer);
+
+static struct attribute *ad7150_attributes[] = {
+	&iio_dev_attr_available_threshold_modes.dev_attr.attr,
+	&iio_dev_attr_threshold_mode.dev_attr.attr,
+	&iio_dev_attr_ch1_threshold.dev_attr.attr,
+	&iio_dev_attr_ch2_threshold.dev_attr.attr,
+	&iio_dev_attr_ch1_timeout.dev_attr.attr,
+	&iio_dev_attr_ch2_timeout.dev_attr.attr,
+	&iio_dev_attr_ch1_setup.dev_attr.attr,
+	&iio_dev_attr_ch2_setup.dev_attr.attr,
+	&iio_dev_attr_ch1_sensitivity.dev_attr.attr,
+	&iio_dev_attr_ch2_sensitivity.dev_attr.attr,
+	&iio_dev_attr_powerdown_timer.dev_attr.attr,
+	&iio_dev_attr_ch1_value.dev_attr.attr,
+	&iio_dev_attr_ch2_value.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group ad7150_attribute_group = {
+	.attrs = ad7150_attributes,
+};
+
+/*
+ * threshold events
+ */
+
+#define IIO_EVENT_CODE_CH1_HIGH    IIO_BUFFER_EVENT_CODE(0)
+#define IIO_EVENT_CODE_CH1_LOW     IIO_BUFFER_EVENT_CODE(1)
+#define IIO_EVENT_CODE_CH2_HIGH    IIO_BUFFER_EVENT_CODE(2)
+#define IIO_EVENT_CODE_CH2_LOW     IIO_BUFFER_EVENT_CODE(3)
+
+#define IIO_EVENT_ATTR_CH1_HIGH_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ch1_high, _evlist, _show, _store, _mask)
+
+#define IIO_EVENT_ATTR_CH2_HIGH_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ch2_high, _evlist, _show, _store, _mask)
+
+#define IIO_EVENT_ATTR_CH1_LOW_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ch1_low, _evlist, _show, _store, _mask)
+
+#define IIO_EVENT_ATTR_CH2_LOW_SH(_evlist, _show, _store, _mask)	\
+	IIO_EVENT_ATTR_SH(ch2_low, _evlist, _show, _store, _mask)
+
+static void ad7150_interrupt_handler_bh(struct work_struct *work_s)
+{
+	struct ad7150_chip_info *chip =
+		container_of(work_s, struct ad7150_chip_info, thresh_work);
+	u8 int_status;
+
+	enable_irq(chip->client->irq);
+
+	ad7150_i2c_read(chip, AD7150_STATUS, &int_status, 1);
+
+	if ((int_status & AD7150_STATUS_OUT1) && !(chip->old_state & AD7150_STATUS_OUT1))
+		iio_push_event(chip->indio_dev, 0,
+				IIO_EVENT_CODE_CH1_HIGH,
+				chip->last_timestamp);
+	else if ((!(int_status & AD7150_STATUS_OUT1)) && (chip->old_state & AD7150_STATUS_OUT1))
+		iio_push_event(chip->indio_dev, 0,
+				IIO_EVENT_CODE_CH1_LOW,
+				chip->last_timestamp);
+
+	if ((int_status & AD7150_STATUS_OUT2) && !(chip->old_state & AD7150_STATUS_OUT2))
+		iio_push_event(chip->indio_dev, 0,
+				IIO_EVENT_CODE_CH2_HIGH,
+				chip->last_timestamp);
+	else if ((!(int_status & AD7150_STATUS_OUT2)) && (chip->old_state & AD7150_STATUS_OUT2))
+		iio_push_event(chip->indio_dev, 0,
+				IIO_EVENT_CODE_CH2_LOW,
+				chip->last_timestamp);
+}
+
+static int ad7150_interrupt_handler_th(struct iio_dev *dev_info,
+		int index,
+		s64 timestamp,
+		int no_test)
+{
+	struct ad7150_chip_info *chip = dev_info->dev_data;
+
+	chip->last_timestamp = timestamp;
+	schedule_work(&chip->thresh_work);
+
+	return 0;
+}
+
+IIO_EVENT_SH(threshold, &ad7150_interrupt_handler_th);
+
+static ssize_t ad7150_query_out_mode(struct device *dev,
+		struct device_attribute *attr,
+		char *buf)
+{
+	/*
+	 * AD7150 provides two logic output channels, which can be used as interrupt
+	 * but the pins are not configurable
+	 */
+	return sprintf(buf, "1\n");
+}
+
+static ssize_t ad7150_set_out_mode(struct device *dev,
+		struct device_attribute *attr,
+		const char *buf,
+		size_t len)
+{
+	return len;
+}
+
+IIO_EVENT_ATTR_CH1_HIGH_SH(iio_event_threshold, ad7150_query_out_mode, ad7150_set_out_mode, 0);
+IIO_EVENT_ATTR_CH2_HIGH_SH(iio_event_threshold, ad7150_query_out_mode, ad7150_set_out_mode, 0);
+IIO_EVENT_ATTR_CH1_LOW_SH(iio_event_threshold, ad7150_query_out_mode, ad7150_set_out_mode, 0);
+IIO_EVENT_ATTR_CH2_LOW_SH(iio_event_threshold, ad7150_query_out_mode, ad7150_set_out_mode, 0);
+
+static struct attribute *ad7150_event_attributes[] = {
+	&iio_event_attr_ch1_high.dev_attr.attr,
+	&iio_event_attr_ch2_high.dev_attr.attr,
+	&iio_event_attr_ch1_low.dev_attr.attr,
+	&iio_event_attr_ch2_low.dev_attr.attr,
+	NULL,
+};
+
+static struct attribute_group ad7150_event_attribute_group = {
+	.attrs = ad7150_event_attributes,
+};
+
+/*
+ * device probe and remove
+ */
+
+static int __devinit ad7150_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	int ret = 0, regdone = 0;
+	struct ad7150_chip_info *chip = kzalloc(sizeof(*chip), GFP_KERNEL);
+	if (chip == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+
+	/* this is only used for device removal purposes */
+	i2c_set_clientdata(client, chip);
+
+	chip->client = client;
+	chip->name = id->name;
+
+	chip->indio_dev = iio_allocate_device();
+	if (chip->indio_dev == NULL) {
+		ret = -ENOMEM;
+		goto error_free_chip;
+	}
+
+	/* Echipabilish that the iio_dev is a child of the i2c device */
+	chip->indio_dev->dev.parent = &client->dev;
+	chip->indio_dev->attrs = &ad7150_attribute_group;
+	chip->indio_dev->event_attrs = &ad7150_event_attribute_group;
+	chip->indio_dev->dev_data = (void *)(chip);
+	chip->indio_dev->driver_module = THIS_MODULE;
+	chip->indio_dev->num_interrupt_lines = 1;
+	chip->indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = iio_device_register(chip->indio_dev);
+	if (ret)
+		goto error_free_dev;
+	regdone = 1;
+
+	if (client->irq && gpio_is_valid(irq_to_gpio(client->irq)) > 0) {
+		ret = iio_register_interrupt_line(client->irq,
+				chip->indio_dev,
+				0,
+				IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+				"ad7150");
+		if (ret)
+			goto error_free_dev;
+
+		iio_add_event_to_list(iio_event_attr_ch2_low.listel,
+				&chip->indio_dev->interrupts[0]->ev_list);
+
+		INIT_WORK(&chip->thresh_work, ad7150_interrupt_handler_bh);
+	}
+
+	dev_err(&client->dev, "%s capacitive sensor registered, irq: %d\n", id->name, client->irq);
+
+	return 0;
+
+error_free_dev:
+	if (regdone)
+		iio_device_unregister(chip->indio_dev);
+	else
+		iio_free_device(chip->indio_dev);
+error_free_chip:
+	kfree(chip);
+error_ret:
+	return ret;
+}
+
+static int __devexit ad7150_remove(struct i2c_client *client)
+{
+	struct ad7150_chip_info *chip = i2c_get_clientdata(client);
+	struct iio_dev *indio_dev = chip->indio_dev;
+
+	if (client->irq && gpio_is_valid(irq_to_gpio(client->irq)) > 0)
+		iio_unregister_interrupt_line(indio_dev, 0);
+	iio_device_unregister(indio_dev);
+	kfree(chip);
+
+	return 0;
+}
+
+static const struct i2c_device_id ad7150_id[] = {
+	{ "ad7150", 0 },
+	{ "ad7151", 0 },
+	{ "ad7156", 0 },
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, ad7150_id);
+
+static struct i2c_driver ad7150_driver = {
+	.driver = {
+		.name = "ad7150",
+	},
+	.probe = ad7150_probe,
+	.remove = __devexit_p(ad7150_remove),
+	.id_table = ad7150_id,
+};
+
+static __init int ad7150_init(void)
+{
+	return i2c_add_driver(&ad7150_driver);
+}
+
+static __exit void ad7150_exit(void)
+{
+	i2c_del_driver(&ad7150_driver);
+}
+
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_DESCRIPTION("Analog Devices ad7150/1/6 capacitive sensor driver");
+MODULE_LICENSE("GPL v2");
+
+module_init(ad7150_init);
+module_exit(ad7150_exit);
-- 
1.7.3.2