diff mbox

[v5] input/misc: add Analog Devices AD714x captouch input driver

Message ID 1256027864-26126-1-git-send-email-vapier@gentoo.org
State New, archived
Headers show

Commit Message

Mike Frysinger Oct. 20, 2009, 8:37 a.m. UTC
None
diff mbox

Patch

diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 02f4f8f..fc4b0b9 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -316,4 +316,34 @@  config INPUT_PCAP
 	  To compile this driver as a module, choose M here: the
 	  module will be called pcap_keys.
 
+config INPUT_AD714X
+	tristate "Analog Devices AD714x Capacitance Touch Sensor"
+	help
+	  Say Y here if you want to support an AD7142/AD7147 touch sensor.
+
+	  You should select a bus connection too.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad714x.
+
+config INPUT_AD714X_I2C
+	tristate "support I2C bus connection"
+	depends on INPUT_AD714X && I2C
+	default y
+	help
+	  Say Y here if you have AD7142/AD7147 hooked to an I2C bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad714x-i2c.
+
+config INPUT_AD714X_SPI
+	tristate "support SPI bus connection"
+	depends on INPUT_AD714X && SPI
+	default y
+	help
+	  Say Y here if you have AD7142/AD7147 hooked to a SPI bus.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad714x-spi.
+
 endif
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index a8b8485..16db64a 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -4,6 +4,9 @@ 
 
 # Each configuration option enables a list of files.
 
+obj-$(CONFIG_INPUT_AD714X)		+= ad714x.o
+obj-$(CONFIG_INPUT_AD714X_I2C)		+= ad714x-i2c.o
+obj-$(CONFIG_INPUT_AD714X_SPI)		+= ad714x-spi.o
 obj-$(CONFIG_INPUT_APANEL)		+= apanel.o
 obj-$(CONFIG_INPUT_ATI_REMOTE)		+= ati_remote.o
 obj-$(CONFIG_INPUT_ATI_REMOTE2)		+= ati_remote2.o
diff --git a/drivers/input/misc/ad714x-i2c.c b/drivers/input/misc/ad714x-i2c.c
new file mode 100644
index 0000000..596c199
--- /dev/null
+++ b/drivers/input/misc/ad714x-i2c.c
@@ -0,0 +1,134 @@ 
+/*
+ * AD714X CapTouch Programmable Controller driver (I2C bus)
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/input.h>	/* BUS_I2C */
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include "ad714x.h"
+
+#ifdef CONFIG_PM
+static int ad714x_i2c_suspend(struct i2c_client *client, pm_message_t message)
+{
+	return ad714x_disable(i2c_get_clientdata(client));
+}
+
+static int ad714x_i2c_resume(struct i2c_client *client)
+{
+	return ad714x_enable(i2c_get_clientdata(client));
+}
+#else
+# define ad714x_i2c_suspend NULL
+# define ad714x_i2c_resume  NULL
+#endif
+
+static int ad714x_i2c_write(struct device *dev, unsigned short reg,
+		unsigned short data)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret = 0;
+	u8 *_reg = (u8 *)&reg;
+	u8 *_data = (u8 *)&data;
+
+	u8 tx[4] = {
+		_reg[1],
+		_reg[0],
+		_data[1],
+		_data[0]
+	};
+
+	ret = i2c_master_send(client, tx, 4);
+	if (ret < 0)
+		dev_err(&client->dev, "I2C write error\n");
+
+	return ret;
+}
+
+static int ad714x_i2c_read(struct device *dev, unsigned short reg,
+		unsigned short *data)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret = 0;
+	u8 *_reg = (u8 *)&reg;
+	u8 *_data = (u8 *)data;
+
+	u8 tx[2] = {
+		_reg[1],
+		_reg[0]
+	};
+	u8 rx[2];
+
+	ret = i2c_master_send(client, tx, 2);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C read error\n");
+		return ret;
+	}
+
+	ret = i2c_master_recv(client, rx, 2);
+	if (ret < 0) {
+		dev_err(&client->dev, "I2C read error\n");
+		return ret;
+	}
+
+	_data[0] = rx[1];
+	_data[1] = rx[0];
+
+	return ret;
+}
+
+static int __devinit ad714x_i2c_probe(struct i2c_client *client,
+		const struct i2c_device_id *id)
+{
+	int ret = 0;
+	struct ad714x_chip *chip = NULL;
+
+	ret = ad714x_probe(&chip, &client->dev, BUS_I2C, client->irq,
+		ad714x_i2c_read, ad714x_i2c_write);
+	i2c_set_clientdata(client, chip);
+
+	return ret;
+}
+
+static int __devexit ad714x_i2c_remove(struct i2c_client *client)
+{
+	return ad714x_remove(i2c_get_clientdata(client));
+}
+
+static const struct i2c_device_id ad714x_id[] = {
+	{ "ad7142_captouch", 0 },
+	{ "ad7147_captouch", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ad714x_id);
+
+static struct i2c_driver ad714x_i2c_driver = {
+	.driver = {
+		.name = "ad714x_captouch",
+	},
+	.probe    = ad714x_i2c_probe,
+	.remove   = __devexit_p(ad714x_i2c_remove),
+	.suspend  = ad714x_i2c_suspend,
+	.resume	  = ad714x_i2c_resume,
+	.id_table = ad714x_id,
+};
+
+static __init int ad714x_i2c_init(void)
+{
+	return i2c_add_driver(&ad714x_i2c_driver);
+}
+module_init(ad714x_i2c_init);
+
+static __exit void ad714x_i2c_exit(void)
+{
+	i2c_del_driver(&ad714x_i2c_driver);
+}
+module_exit(ad714x_i2c_exit);
+
+MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/input/misc/ad714x-spi.c b/drivers/input/misc/ad714x-spi.c
new file mode 100644
index 0000000..2cea1e4
--- /dev/null
+++ b/drivers/input/misc/ad714x-spi.c
@@ -0,0 +1,96 @@ 
+/*
+ * AD714X CapTouch Programmable Controller driver (SPI bus)
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/input.h>	/* BUS_I2C */
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include "ad714x.h"
+
+#define AD714x_SPI_CMD_PREFIX      0xE000   /* bits 15:11 */
+#define AD714x_SPI_READ            BIT(10)
+
+#ifdef CONFIG_PM
+static int ad714x_spi_suspend(struct spi_device *spi, pm_message_t message)
+{
+	return ad714x_disable(spi_get_drvdata(spi));
+}
+
+static int ad714x_spi_resume(struct spi_device *spi)
+{
+	return ad714x_enable(spi_get_drvdata(spi));
+}
+#else
+# define ad714x_spi_suspend NULL
+# define ad714x_spi_resume  NULL
+#endif
+
+static int ad714x_spi_read(struct device *dev, unsigned short reg,
+		unsigned short *data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned short tx = AD714x_SPI_CMD_PREFIX | AD714x_SPI_READ | reg;
+
+	return spi_write_then_read(spi, (u8 *)&tx, 2, (u8 *)data, 2);
+}
+
+static int ad714x_spi_write(struct device *dev, unsigned short reg,
+		unsigned short data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	unsigned short tx[2] = {
+		AD714x_SPI_CMD_PREFIX | reg,
+		data
+	};
+
+	return spi_write(spi, (u8 *)tx, 4);
+}
+
+static int __devinit ad714x_spi_probe(struct spi_device *spi)
+{
+	int ret;
+	struct ad714x_chip *chip = NULL;
+
+	ret = ad714x_probe(&chip, &spi->dev, BUS_SPI, spi->irq,
+		ad714x_spi_read, ad714x_spi_write);
+	spi_set_drvdata(spi, chip);
+
+	return ret;
+}
+
+static int __devexit ad714x_spi_remove(struct spi_device *spi)
+{
+	return ad714x_remove(spi_get_drvdata(spi));
+}
+
+static struct spi_driver ad714x_spi_driver = {
+	.driver = {
+		.name	= "ad714x_captouch",
+		.owner	= THIS_MODULE,
+	},
+	.probe		= ad714x_spi_probe,
+	.remove		= __devexit_p(ad714x_spi_remove),
+	.suspend	= ad714x_spi_suspend,
+	.resume		= ad714x_spi_resume,
+};
+
+static __init int ad714x_spi_init(void)
+{
+	return spi_register_driver(&ad714x_spi_driver);
+}
+module_init(ad714x_spi_init);
+
+static __exit void ad714x_spi_exit(void)
+{
+	spi_unregister_driver(&ad714x_spi_driver);
+}
+module_exit(ad714x_spi_exit);
+
+MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/input/misc/ad714x.c b/drivers/input/misc/ad714x.c
new file mode 100644
index 0000000..d22509d
--- /dev/null
+++ b/drivers/input/misc/ad714x.c
@@ -0,0 +1,1305 @@ 
+/*
+ * AD714X CapTouch Programmable Controller driver
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/input/ad714x.h>
+#include "ad714x.h"
+
+#define AD714X_PWR_CTRL           0x0
+#define AD714X_STG_CAL_EN_REG     0x1
+#define AD714X_AMB_COMP_CTRL0_REG 0x2
+#define AD714X_PARTID_REG         0x17
+#define AD7147_PARTID             0x1470
+#define AD7142_PARTID             0xE620
+#define AD714X_STAGECFG_REG       0x80
+#define AD714X_SYSCFG_REG         0x0
+
+#define STG_LOW_INT_EN_REG     0x5
+#define STG_HIGH_INT_EN_REG    0x6
+#define STG_COM_INT_EN_REG     0x7
+#define STG_LOW_INT_STA_REG    0x8
+#define STG_HIGH_INT_STA_REG   0x9
+#define STG_COM_INT_STA_REG    0xA
+
+#define CDC_RESULT_S0          0xB
+#define CDC_RESULT_S1          0xC
+#define CDC_RESULT_S2          0xD
+#define CDC_RESULT_S3          0xE
+#define CDC_RESULT_S4          0xF
+#define CDC_RESULT_S5          0x10
+#define CDC_RESULT_S6          0x11
+#define CDC_RESULT_S7          0x12
+#define CDC_RESULT_S8          0x13
+#define CDC_RESULT_S9          0x14
+#define CDC_RESULT_S10         0x15
+#define CDC_RESULT_S11         0x16
+
+#define STAGE0_AMBIENT		0xF1
+#define STAGE1_AMBIENT		0x115
+#define STAGE2_AMBIENT		0x139
+#define STAGE3_AMBIENT		0x15D
+#define STAGE4_AMBIENT		0x181
+#define STAGE5_AMBIENT		0x1A5
+#define STAGE6_AMBIENT		0x1C9
+#define STAGE7_AMBIENT		0x1ED
+#define STAGE8_AMBIENT		0x211
+#define STAGE9_AMBIENT		0x234
+#define STAGE10_AMBIENT		0x259
+#define STAGE11_AMBIENT		0x27D
+
+#define PER_STAGE_REG_NUM      36
+#define STAGE_NUM              12
+#define STAGE_CFGREG_NUM       8
+#define SYS_CFGREG_NUM         8
+
+/*
+ * driver information which will be used to maintain the software flow
+ */
+typedef enum {IDLE, JITTER, ACTIVE, SPACE} ad714x_device_state;
+
+struct ad714x_slider_drv {
+	int highest_stage;
+	int abs_pos;
+	int flt_pos;
+	ad714x_device_state state;
+	struct input_dev *input;
+};
+
+struct ad714x_wheel_drv {
+	int abs_pos;
+	int flt_pos;
+	int pre_mean_value;
+	int pre_highest_stage;
+	int pre_mean_value_no_offset;
+	int mean_value;
+	int mean_value_no_offset;
+	int pos_offset;
+	int pos_ratio;
+	int highest_stage;
+	ad714x_device_state state;
+	struct input_dev *input;
+};
+
+struct ad714x_touchpad_drv {
+	int x_highest_stage;
+	int x_flt_pos;
+	int x_abs_pos;
+	int y_highest_stage;
+	int y_flt_pos;
+	int y_abs_pos;
+	int left_ep;
+	int left_ep_val;
+	int right_ep;
+	int right_ep_val;
+	int top_ep;
+	int top_ep_val;
+	int bottom_ep;
+	int bottom_ep_val;
+	ad714x_device_state state;
+	struct input_dev *input;
+};
+
+struct ad714x_button_drv {
+	ad714x_device_state state;
+	/* Unlike slider/wheel/touchpad, all buttons point to
+	 * same input_dev instance
+	 */
+	struct input_dev *input;
+};
+
+struct ad714x_driver_data {
+	struct ad714x_slider_drv *slider;
+	struct ad714x_wheel_drv *wheel;
+	struct ad714x_touchpad_drv *touchpad;
+	struct ad714x_button_drv *button;
+};
+
+/* information to integrate all things which will be private data
+ * of spi/i2c device
+ */
+struct ad714x_chip {
+	unsigned short h_state;
+	unsigned short l_state;
+	unsigned short c_state;
+	unsigned short adc_reg[STAGE_NUM];
+	unsigned short amb_reg[STAGE_NUM];
+	unsigned short sensor_val[STAGE_NUM];
+
+	struct ad714x_platform_data *hw;
+	struct ad714x_driver_data *sw;
+
+	int irq;
+	struct device *dev;
+	ad714x_read_t *read;
+	ad714x_write_t *write;
+
+	struct mutex mutex;
+
+	unsigned product;
+	unsigned version;
+};
+
+static void ad714x_use_com_int(struct ad714x_chip *ad714x, int start_stage,
+		int end_stage)
+{
+	unsigned short data;
+	unsigned short mask;
+
+	mask = ((1 << (end_stage + 1)) - 1) - (1 << start_stage);
+
+	ad714x->read(ad714x->dev, STG_COM_INT_EN_REG, &data);
+	data |= 1 << start_stage;
+	ad714x->write(ad714x->dev, STG_COM_INT_EN_REG, data);
+
+	ad714x->read(ad714x->dev, STG_HIGH_INT_EN_REG, &data);
+	data &= ~mask;
+	ad714x->write(ad714x->dev, STG_HIGH_INT_EN_REG, data);
+}
+
+static void ad714x_use_thr_int(struct ad714x_chip *ad714x, int start_stage,
+		int end_stage)
+{
+	unsigned short data;
+	unsigned short mask;
+
+	mask = ((1 << (end_stage + 1)) - 1) - (1 << start_stage);
+
+	ad714x->read(ad714x->dev, STG_COM_INT_EN_REG, &data);
+	data &= ~(1 << start_stage);
+	ad714x->write(ad714x->dev, STG_COM_INT_EN_REG, data);
+
+	ad714x->read(ad714x->dev, STG_HIGH_INT_EN_REG, &data);
+	data |= mask;
+	ad714x->write(ad714x->dev, STG_HIGH_INT_EN_REG, data);
+}
+
+static int ad714x_cal_highest_stage(struct ad714x_chip *ad714x, int start_stage,
+		int end_stage)
+{
+	int max_res = 0;
+	int max_idx = 0;
+	int i;
+
+	for (i = start_stage; i <= end_stage; i++) {
+		if (ad714x->sensor_val[i] > max_res) {
+			max_res = ad714x->sensor_val[i];
+			max_idx = i;
+		}
+	}
+
+	return max_idx;
+}
+
+static int ad714x_cal_abs_pos(struct ad714x_chip *ad714x, int start_stage,
+		int end_stage, int highest_stage, int max_coord)
+{
+	int a_param, b_param;
+
+	if (highest_stage == start_stage) {
+		a_param = ad714x->sensor_val[start_stage + 1];
+		b_param = ad714x->sensor_val[start_stage] +
+			ad714x->sensor_val[start_stage + 1];
+	} else if (highest_stage == end_stage) {
+		a_param = ad714x->sensor_val[end_stage] *
+			(end_stage - start_stage) +
+			ad714x->sensor_val[end_stage - 1] *
+			(end_stage - start_stage - 1);
+		b_param = ad714x->sensor_val[end_stage] +
+			ad714x->sensor_val[end_stage - 1];
+	} else {
+		a_param = ad714x->sensor_val[highest_stage] *
+			(highest_stage - start_stage) +
+			ad714x->sensor_val[highest_stage - 1] *
+			(highest_stage - start_stage - 1) +
+			ad714x->sensor_val[highest_stage + 1] *
+			(highest_stage - start_stage + 1);
+		b_param = ad714x->sensor_val[highest_stage] +
+			ad714x->sensor_val[highest_stage - 1] +
+			ad714x->sensor_val[highest_stage + 1];
+	}
+
+	return (max_coord / (end_stage - start_stage)) * a_param / b_param;
+}
+
+
+/* One button can connect to multi positive and negative of CDCs
+ * Multi-buttons can connect to same positive/negative of one CDC
+ */
+static void ad714x_button_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_button_plat *hw = &ad714x->hw->button[idx];
+	struct ad714x_button_drv *sw = &ad714x->sw->button[idx];
+
+	switch (sw->state) {
+	case IDLE:
+		if (((ad714x->h_state & hw->h_mask) == hw->h_mask) &&
+			((ad714x->l_state & hw->l_mask) == hw->l_mask)) {
+			dev_dbg(ad714x->dev, "button %d touched\n", idx);
+			input_report_key(sw->input, hw->keycode, 1);
+			input_sync(sw->input);
+			sw->state = ACTIVE;
+		}
+		break;
+	case ACTIVE:
+		if (((ad714x->h_state & hw->h_mask) != hw->h_mask) ||
+			((ad714x->l_state & hw->l_mask) != hw->l_mask)) {
+			dev_dbg(ad714x->dev, "button %d released\n", idx);
+			input_report_key(sw->input, hw->keycode, 0);
+			input_sync(sw->input);
+			sw->state = IDLE;
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+/* The response of a sensor is defined by the absolute number of codes
+ * between the current CDC value and the ambient value.
+ */
+void ad714x_slider_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	int i;
+
+	for (i = hw->start_stage; i <= hw->end_stage; i++) {
+		ad714x->read(ad714x->dev, CDC_RESULT_S0 + i,
+			&ad714x->adc_reg[i]);
+		ad714x->read(ad714x->dev,
+				STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+				&ad714x->amb_reg[i]);
+
+		ad714x->sensor_val[i] = abs(ad714x->adc_reg[i] -
+				ad714x->amb_reg[i]);
+	}
+}
+
+void ad714x_slider_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
+			hw->end_stage);
+
+	dev_dbg(ad714x->dev, "slider %d highest_stage:%d\n", idx,
+		sw->highest_stage);
+}
+
+/* The formulae are very straight forward. It uses the sensor with the
+ * highest response and the 2 adjacent ones.
+ * When Sensor 0 has the highest response, only sensor 0 and sensor 1
+ * are used in the calculations. Similarly when the last sensor has the
+ * highest response, only the last sensor and the second last sensors
+ * are used in the calculations.
+ *
+ * For i= idx_of_peak_Sensor-1 to i= idx_of_peak_Sensor+1
+ *         v += Sensor response(i)*i
+ *         w += Sensor response(i)
+ * POS=(Number_of_Positions_Wanted/(Number_of_Sensors_Used-1)) *(v/w)
+ */
+void ad714x_slider_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+	sw->abs_pos = ad714x_cal_abs_pos(ad714x, hw->start_stage, hw->end_stage,
+		sw->highest_stage, hw->max_coord);
+
+	dev_dbg(ad714x->dev, "slider %d absolute position:%d\n", idx,
+		sw->abs_pos);
+}
+
+/*
+ * To minimise the Impact of the noise on the algorithm, ADI developed a
+ * routine that filters the CDC results after they have been read by the
+ * host processor.
+ * The filter used is an Infinite Input Response(IIR) filter implemented
+ * in firmware and attenuates the noise on the CDC results after they've
+ * been read by the host processor.
+ * Filtered_CDC_result = (Filtered_CDC_result * (10 - Coefficient) +
+ * 				Latest_CDC_result * Coefficient)/10
+ */
+void ad714x_slider_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+
+	sw->flt_pos = (sw->flt_pos * (10 - 4) +
+			sw->abs_pos * 4)/10;
+
+	dev_dbg(ad714x->dev, "slider %d filter position:%d\n", idx,
+		sw->flt_pos);
+}
+
+static void ad714x_slider_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_slider_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_slider_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_slider_plat *hw = &ad714x->hw->slider[idx];
+	struct ad714x_slider_drv *sw = &ad714x->sw->slider[idx];
+	unsigned short h_state, c_state;
+	unsigned short mask;
+
+	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
+
+	h_state = ad714x->h_state & mask;
+	c_state = ad714x->c_state & mask;
+
+	switch (sw->state) {
+	case IDLE:
+		if (h_state) {
+			sw->state = JITTER;
+			/* In End of Conversion interrupt mode, the AD714X
+			 * continuously generates hardware interrupts.
+			 */
+			ad714x_slider_use_com_int(ad714x, idx);
+			dev_dbg(ad714x->dev, "slider %d touched\n", idx);
+		}
+		break;
+	case JITTER:
+		if (c_state == mask) {
+			ad714x_slider_cal_sensor_val(ad714x, idx);
+			ad714x_slider_cal_highest_stage(ad714x, idx);
+			ad714x_slider_cal_abs_pos(ad714x, idx);
+			sw->flt_pos = sw->abs_pos;
+			sw->state = ACTIVE;
+		}
+		break;
+	case ACTIVE:
+		if (c_state == mask) {
+			if (h_state) {
+				ad714x_slider_cal_sensor_val(ad714x, idx);
+				ad714x_slider_cal_highest_stage(ad714x, idx);
+				ad714x_slider_cal_abs_pos(ad714x, idx);
+				ad714x_slider_cal_flt_pos(ad714x, idx);
+
+				input_report_abs(sw->input, ABS_X, sw->flt_pos);
+				input_report_key(sw->input, BTN_TOUCH, 1);
+			} else {
+				/* When the user lifts off the sensor, configure
+				 * the AD714X back to threshold interrupt mode.
+				 */
+				ad714x_slider_use_thr_int(ad714x, idx);
+				sw->state = IDLE;
+				input_report_key(sw->input, BTN_TOUCH, 0);
+				dev_dbg(ad714x->dev, "slider %d released\n",
+					idx);
+			}
+			input_sync(sw->input);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+/* When the scroll wheel is activated, we compute the absolute position based
+ * on the sensor values. To calculate the position, we first determine the
+ * sensor that has the greatest response among the 8 sensors that constitutes
+ * the scrollwheel. Then we determined the 2 sensors on either sides of the
+ * sensor with the highest response and we apply weights to these sensors.
+ */
+static void ad714x_wheel_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+
+	sw->pre_highest_stage = sw->highest_stage;
+	sw->highest_stage = ad714x_cal_highest_stage(ad714x, hw->start_stage,
+			hw->end_stage);
+
+	dev_dbg(ad714x->dev, "wheel %d highest_stage:%d\n", idx,
+		sw->highest_stage);
+}
+
+static void ad714x_wheel_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	int i;
+
+	for (i = hw->start_stage; i <= hw->end_stage; i++) {
+		ad714x->read(ad714x->dev, CDC_RESULT_S0 + i,
+			&ad714x->adc_reg[i]);
+		ad714x->read(ad714x->dev,
+				STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+				&ad714x->amb_reg[i]);
+		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
+			ad714x->sensor_val[i] = ad714x->adc_reg[i] -
+				ad714x->amb_reg[i];
+		else
+			ad714x->sensor_val[i] = 0;
+	}
+}
+
+/* When the scroll wheel is activated, we compute the absolute position based
+ * on the sensor values. To calculate the position, we first determine the
+ * sensor that has the greatest response among the 8 sensors that constitutes
+ * the scrollwheel. Then we determined the 2 sensors on either sides of the
+ * sensor with the highest response and we apply weights to these sensors. The
+ * result of this computation gives us the mean value which defined by the
+ * following formula:
+ * For i= second_before_highest_stage to i= second_after_highest_stage
+ *         v += Sensor response(i)*WEIGHT*(i+3)
+ *         w += Sensor response(i)
+ * Mean_Value=v/w
+ * pos_on_scrollwheel = (Mean_Value - position_offset) / position_ratio
+ *
+ */
+
+#define WEIGHT_FACTOR 30
+/* This constant prevents the "PositionOffset" from reaching a big value */
+#define OFFSET_POSITION_CLAMP	120
+static void ad714x_wheel_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+	int stage_num = hw->end_stage - hw->start_stage + 1;
+	int second_before, first_before, highest, first_after, second_after;
+	int a_param, b_param;
+
+	/* Calculate Mean value */
+
+	second_before = (sw->highest_stage + stage_num - 2) % stage_num;
+	first_before = (sw->highest_stage + stage_num - 1) % stage_num;
+	highest = sw->highest_stage;
+	first_after = (sw->highest_stage + stage_num + 1) % stage_num;
+	second_after = (sw->highest_stage + stage_num + 2) % stage_num;
+
+	if (((sw->highest_stage - hw->start_stage) > 1) &&
+			((hw->end_stage - sw->highest_stage) > 1)) {
+		a_param = ad714x->sensor_val[second_before] *
+			(second_before - hw->start_stage + 3) +
+			ad714x->sensor_val[first_before] *
+			(second_before - hw->start_stage + 3) +
+			ad714x->sensor_val[highest] *
+			(second_before - hw->start_stage + 3) +
+			ad714x->sensor_val[first_after] *
+			(first_after - hw->start_stage + 3) +
+			ad714x->sensor_val[second_after] *
+			(second_after - hw->start_stage + 3);
+	} else {
+		a_param = ad714x->sensor_val[second_before] *
+			(second_before - hw->start_stage + 1) +
+			ad714x->sensor_val[first_before] *
+			(second_before - hw->start_stage + 2) +
+			ad714x->sensor_val[highest] *
+			(second_before - hw->start_stage + 3) +
+			ad714x->sensor_val[first_after] *
+			(first_after - hw->start_stage + 4) +
+			ad714x->sensor_val[second_after] *
+			(second_after - hw->start_stage + 5);
+	}
+	a_param *= WEIGHT_FACTOR;
+
+	b_param = ad714x->sensor_val[second_before] +
+		ad714x->sensor_val[first_before] +
+		ad714x->sensor_val[highest] +
+		ad714x->sensor_val[first_after] +
+		ad714x->sensor_val[second_after];
+
+	sw->pre_mean_value = sw->mean_value;
+	sw->mean_value = a_param / b_param;
+
+	/* Calculate the offset */
+
+	if ((sw->pre_highest_stage == hw->end_stage) &&
+			(sw->highest_stage == hw->start_stage))
+		sw->pos_offset = sw->mean_value;
+	else if ((sw->pre_highest_stage == hw->start_stage) &&
+			(sw->highest_stage == hw->end_stage))
+		sw->pos_offset = sw->pre_mean_value;
+	if (sw->pos_offset > OFFSET_POSITION_CLAMP)
+		sw->pos_offset = OFFSET_POSITION_CLAMP;
+
+	/* Calculate the mean value without the offset */
+
+	sw->pre_mean_value_no_offset = sw->mean_value_no_offset;
+	sw->mean_value_no_offset = sw->mean_value - sw->pos_offset;
+	if (sw->mean_value_no_offset < 0)
+		sw->mean_value_no_offset = 0;
+
+	/* Calculate ratio to scale down to NUMBER_OF_WANTED_POSITIONS */
+
+	if ((sw->pre_highest_stage == hw->end_stage) &&
+			(sw->highest_stage == hw->start_stage))
+		sw->pos_ratio = (sw->pre_mean_value_no_offset * 100) /
+			hw->max_coord;
+	else if ((sw->pre_highest_stage == hw->start_stage) &&
+			(sw->highest_stage == hw->end_stage))
+		sw->pos_ratio = (sw->mean_value_no_offset * 100) /
+			hw->max_coord;
+	sw->abs_pos = (sw->mean_value_no_offset * 100) / sw->pos_ratio;
+	if (sw->abs_pos > hw->max_coord)
+		sw->abs_pos = hw->max_coord;
+}
+
+static void ad714x_wheel_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+	if (((sw->pre_highest_stage == hw->end_stage) &&
+				(sw->highest_stage == hw->start_stage)) ||
+			((sw->pre_highest_stage == hw->start_stage) &&
+			 (sw->highest_stage == hw->end_stage)))
+		sw->flt_pos = sw->abs_pos;
+	else
+		sw->flt_pos = ((sw->flt_pos * 30) + (sw->abs_pos * 71)) / 100;
+
+	if (sw->flt_pos > hw->max_coord)
+		sw->flt_pos = hw->max_coord;
+}
+
+static void ad714x_wheel_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	ad714x_use_com_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_wheel_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	ad714x_use_thr_int(ad714x, hw->start_stage, hw->end_stage);
+}
+
+static void ad714x_wheel_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_wheel_plat *hw = &ad714x->hw->wheel[idx];
+	struct ad714x_wheel_drv *sw = &ad714x->sw->wheel[idx];
+	unsigned short h_state, c_state;
+	unsigned short mask;
+
+	mask = ((1 << (hw->end_stage + 1)) - 1) - ((1 << hw->start_stage) - 1);
+
+	h_state = ad714x->h_state & mask;
+	c_state = ad714x->c_state & mask;
+
+	switch (sw->state) {
+	case IDLE:
+		if (h_state) {
+			sw->state = JITTER;
+			/* In End of Conversion interrupt mode, the AD714X
+			 * continuously generates hardware interrupts.
+			 */
+			ad714x_wheel_use_com_int(ad714x, idx);
+			dev_dbg(ad714x->dev, "wheel %d touched\n", idx);
+		}
+		break;
+	case JITTER:
+		if (c_state == mask)	{
+			ad714x_wheel_cal_sensor_val(ad714x, idx);
+			ad714x_wheel_cal_highest_stage(ad714x, idx);
+			ad714x_wheel_cal_abs_pos(ad714x, idx);
+			sw->flt_pos = sw->abs_pos;
+			sw->state = ACTIVE;
+		}
+		break;
+	case ACTIVE:
+		if (c_state == mask) {
+			if (h_state) {
+				ad714x_wheel_cal_sensor_val(ad714x, idx);
+				ad714x_wheel_cal_highest_stage(ad714x, idx);
+				ad714x_wheel_cal_abs_pos(ad714x, idx);
+				ad714x_wheel_cal_flt_pos(ad714x, idx);
+
+				input_report_abs(sw->input, ABS_WHEEL,
+					sw->abs_pos);
+				input_report_key(sw->input, BTN_TOUCH, 1);
+			} else {
+				/* When the user lifts off the sensor, configure
+				 * the AD714X back to threshold interrupt mode.
+				 */
+				ad714x_wheel_use_thr_int(ad714x, idx);
+				sw->state = IDLE;
+				input_report_key(sw->input, BTN_TOUCH, 0);
+
+				dev_dbg(ad714x->dev, "wheel %d released\n",
+					idx);
+			}
+			input_sync(sw->input);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static void touchpad_cal_sensor_val(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	int i;
+
+	for (i = hw->x_start_stage; i <= hw->x_end_stage; i++) {
+		ad714x->read(ad714x->dev, CDC_RESULT_S0 + i,
+				&ad714x->adc_reg[i]);
+		ad714x->read(ad714x->dev,
+				STAGE0_AMBIENT + i * PER_STAGE_REG_NUM,
+				&ad714x->amb_reg[i]);
+		if (ad714x->adc_reg[i] > ad714x->amb_reg[i])
+			ad714x->sensor_val[i] = ad714x->adc_reg[i] -
+				ad714x->amb_reg[i];
+		else
+			ad714x->sensor_val[i] = 0;
+	}
+}
+
+static void touchpad_cal_highest_stage(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+	sw->x_highest_stage = ad714x_cal_highest_stage(ad714x,
+		hw->x_start_stage, hw->x_end_stage);
+	sw->y_highest_stage = ad714x_cal_highest_stage(ad714x,
+		hw->y_start_stage, hw->y_end_stage);
+
+	dev_dbg(ad714x->dev,
+		"touchpad %d x_highest_stage:%d, y_highest_stage:%d\n",
+		idx, sw->x_highest_stage, sw->y_highest_stage);
+}
+
+/* If 2 fingers are touching the sensor then 2 peaks can be observed in the
+ * distribution.
+ * The arithmetic doesn't support to get absolute coordinates for multi-touch
+ * yet.
+ */
+static int touchpad_check_second_peak(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+	int i;
+
+	for (i = hw->x_start_stage; i < sw->x_highest_stage; i++) {
+		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
+			> (ad714x->sensor_val[i + 1] / 10))
+			return 1;
+	}
+
+	for (i = sw->x_highest_stage; i < hw->x_end_stage; i++) {
+		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
+			> (ad714x->sensor_val[i] / 10))
+			return 1;
+	}
+
+	for (i = hw->y_start_stage; i < sw->y_highest_stage; i++) {
+		if ((ad714x->sensor_val[i] - ad714x->sensor_val[i + 1])
+			> (ad714x->sensor_val[i + 1] / 10))
+			return 1;
+	}
+
+	for (i = sw->y_highest_stage; i < hw->y_end_stage; i++) {
+		if ((ad714x->sensor_val[i + 1] - ad714x->sensor_val[i])
+			> (ad714x->sensor_val[i] / 10))
+			return 1;
+	}
+
+	return 0;
+}
+
+/* If only one finger is used to activate the touch pad then only 1 peak will be
+ * registered in the distribution. This peak and the 2 adjacent sensors will be
+ * used in the calculation of the absolute position. This will prevent hand
+ * shadows to affect the absolute position calculation.
+ */
+static void touchpad_cal_abs_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+	sw->x_abs_pos = ad714x_cal_abs_pos(ad714x, hw->x_start_stage,
+			hw->x_end_stage, sw->x_highest_stage, hw->x_max_coord);
+	sw->y_abs_pos = ad714x_cal_abs_pos(ad714x, hw->y_start_stage,
+			hw->y_end_stage, sw->y_highest_stage, hw->y_max_coord);
+
+	dev_dbg(ad714x->dev, "touchpad %d absolute position:(%d, %d)\n", idx,
+			sw->x_abs_pos, sw->y_abs_pos);
+}
+
+static void touchpad_cal_flt_pos(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+
+	sw->x_flt_pos = (sw->x_flt_pos * (10 - 4) +
+			sw->x_abs_pos * 4)/10;
+	sw->y_flt_pos = (sw->y_flt_pos * (10 - 4) +
+			sw->y_abs_pos * 4)/10;
+
+	dev_dbg(ad714x->dev, "touchpad %d filter position:(%d, %d)\n",
+			idx, sw->x_flt_pos, sw->y_flt_pos);
+}
+
+/* To prevent distortion from showing in the absolute position, it is
+ * necessary to detect the end points. When endpoints are detected, the
+ * driver stops updating the status variables with absolute positions.
+ * End points are detected on the 4 edges of the touchpad sensor. The
+ * method to detect them is the same for all 4.
+ * To detect the end points, the firmware computes the difference in
+ * percent between the sensor on the edge and the adjacent one. The
+ * difference is calculated in percent in order to make the end point
+ * detection independent of the pressure.
+ */
+
+#define LEFT_END_POINT_DETECTION_LEVEL                  550
+#define RIGHT_END_POINT_DETECTION_LEVEL                 750
+#define LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL         850
+#define TOP_END_POINT_DETECTION_LEVEL                   550
+#define BOTTOM_END_POINT_DETECTION_LEVEL                950
+#define TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL         700
+static int touchpad_check_endpoint(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	struct ad714x_touchpad_drv *sw  = &ad714x->sw->touchpad[idx];
+	int percent_sensor_diff;
+
+	/* left endpoint detect */
+	percent_sensor_diff = (ad714x->sensor_val[hw->x_start_stage] -
+			ad714x->sensor_val[hw->x_start_stage + 1]) * 100 /
+			ad714x->sensor_val[hw->x_start_stage + 1];
+	if (!sw->left_ep) {
+		if (percent_sensor_diff >= LEFT_END_POINT_DETECTION_LEVEL)  {
+			sw->left_ep = 1;
+			sw->left_ep_val =
+				ad714x->sensor_val[hw->x_start_stage + 1];
+		}
+	} else {
+		if ((percent_sensor_diff < LEFT_END_POINT_DETECTION_LEVEL) &&
+		(ad714x->sensor_val[hw->x_start_stage + 1] >
+		LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->left_ep_val))
+			sw->left_ep = 0;
+	}
+
+	/* right endpoint detect */
+	percent_sensor_diff = (ad714x->sensor_val[hw->x_end_stage] -
+			ad714x->sensor_val[hw->x_end_stage - 1]) * 100 /
+			ad714x->sensor_val[hw->x_end_stage - 1];
+	if (!sw->right_ep) {
+		if (percent_sensor_diff >= RIGHT_END_POINT_DETECTION_LEVEL)  {
+			sw->right_ep = 1;
+			sw->right_ep_val =
+				ad714x->sensor_val[hw->x_end_stage - 1];
+		}
+	} else {
+		if ((percent_sensor_diff < RIGHT_END_POINT_DETECTION_LEVEL) &&
+		(ad714x->sensor_val[hw->x_end_stage - 1] >
+		LEFT_RIGHT_END_POINT_DEAVTIVALION_LEVEL + sw->right_ep_val))
+			sw->right_ep = 0;
+	}
+
+	/* top endpoint detect */
+	percent_sensor_diff = (ad714x->sensor_val[hw->y_start_stage] -
+			ad714x->sensor_val[hw->y_start_stage + 1]) * 100 /
+			ad714x->sensor_val[hw->y_start_stage + 1];
+	if (!sw->top_ep) {
+		if (percent_sensor_diff >= TOP_END_POINT_DETECTION_LEVEL)  {
+			sw->top_ep = 1;
+			sw->top_ep_val =
+				ad714x->sensor_val[hw->y_start_stage + 1];
+		}
+	} else {
+		if ((percent_sensor_diff < TOP_END_POINT_DETECTION_LEVEL) &&
+		(ad714x->sensor_val[hw->y_start_stage + 1] >
+		TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->top_ep_val))
+			sw->top_ep = 0;
+	}
+
+	/* bottom endpoint detect */
+	percent_sensor_diff = (ad714x->sensor_val[hw->y_end_stage] -
+		ad714x->sensor_val[hw->y_end_stage - 1]) * 100 /
+		ad714x->sensor_val[hw->y_end_stage - 1];
+	if (!sw->bottom_ep) {
+		if (percent_sensor_diff >= BOTTOM_END_POINT_DETECTION_LEVEL)  {
+			sw->bottom_ep = 1;
+			sw->bottom_ep_val =
+				ad714x->sensor_val[hw->y_end_stage - 1];
+		}
+	} else {
+		if ((percent_sensor_diff < BOTTOM_END_POINT_DETECTION_LEVEL) &&
+		(ad714x->sensor_val[hw->y_end_stage - 1] >
+		 TOP_BOTTOM_END_POINT_DEAVTIVALION_LEVEL + sw->bottom_ep_val))
+			sw->bottom_ep = 0;
+	}
+
+	return sw->left_ep || sw->right_ep || sw->top_ep || sw->bottom_ep;
+}
+
+static void touchpad_use_com_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	ad714x_use_com_int(ad714x, hw->x_start_stage, hw->x_end_stage);
+}
+
+static void touchpad_use_thr_int(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	ad714x_use_thr_int(ad714x, hw->x_start_stage, hw->x_end_stage);
+	ad714x_use_thr_int(ad714x, hw->y_start_stage, hw->y_end_stage);
+}
+
+static void ad714x_touchpad_state_machine(struct ad714x_chip *ad714x, int idx)
+{
+	struct ad714x_touchpad_plat *hw = &ad714x->hw->touchpad[idx];
+	struct ad714x_touchpad_drv *sw = &ad714x->sw->touchpad[idx];
+	unsigned short h_state, c_state;
+	unsigned short mask;
+
+	mask = (((1 << (hw->x_end_stage + 1)) - 1) -
+		((1 << hw->x_start_stage) - 1)) +
+		(((1 << (hw->y_end_stage + 1)) - 1) -
+		((1 << hw->y_start_stage) - 1));
+
+	h_state = ad714x->h_state & mask;
+	c_state = ad714x->c_state & mask;
+
+	switch (sw->state) {
+	case IDLE:
+		if (h_state) {
+			sw->state = JITTER;
+			/* In End of Conversion interrupt mode, the AD714X
+			 * continuously generates hardware interrupts.
+			 */
+			touchpad_use_com_int(ad714x, idx);
+			dev_dbg(ad714x->dev, "touchpad %d touched\n", idx);
+		}
+		break;
+	case JITTER:
+		if (c_state == mask) {
+			touchpad_cal_sensor_val(ad714x, idx);
+			touchpad_cal_highest_stage(ad714x, idx);
+			if ((!touchpad_check_second_peak(ad714x, idx)) &&
+				(!touchpad_check_endpoint(ad714x, idx))) {
+				dev_dbg(ad714x->dev,
+					"touchpad%d, 2 fingers or endpoint\n",
+					idx);
+				touchpad_cal_abs_pos(ad714x, idx);
+				sw->x_flt_pos = sw->x_abs_pos;
+				sw->y_flt_pos = sw->y_abs_pos;
+				sw->state = ACTIVE;
+			}
+		}
+		break;
+	case ACTIVE:
+		if (c_state == mask) {
+			if (h_state) {
+				touchpad_cal_sensor_val(ad714x, idx);
+				touchpad_cal_highest_stage(ad714x, idx);
+				if ((!touchpad_check_second_peak(ad714x, idx))
+				  && (!touchpad_check_endpoint(ad714x, idx))) {
+					touchpad_cal_abs_pos(ad714x, idx);
+					touchpad_cal_flt_pos(ad714x, idx);
+					input_report_abs(sw->input, ABS_X,
+						sw->x_flt_pos);
+					input_report_abs(sw->input, ABS_Y,
+						sw->y_flt_pos);
+					input_report_key(sw->input, BTN_TOUCH,
+						1);
+				}
+			} else {
+				/* When the user lifts off the sensor, configure
+				 * the AD714X back to threshold interrupt mode.
+				 */
+				touchpad_use_thr_int(ad714x, idx);
+				sw->state = IDLE;
+				input_report_key(sw->input, BTN_TOUCH, 0);
+				dev_dbg(ad714x->dev, "touchpad %d released\n",
+					idx);
+			}
+			input_sync(sw->input);
+		}
+		break;
+	default:
+		break;
+	}
+}
+
+static int ad714x_hw_detect(struct ad714x_chip *ad714x)
+{
+	unsigned short data;
+
+	ad714x->read(ad714x->dev, AD714X_PARTID_REG, &data);
+	switch (data & 0xFFF0) {
+	case AD7147_PARTID:
+		ad714x->product = 0x7147;
+		ad714x->version = data & 0xF;
+		dev_info(ad714x->dev, "found AD7147 captouch, rev:%d\n",
+				ad714x->version);
+		return 0;
+	case AD7142_PARTID:
+		ad714x->product = 0x7142;
+		ad714x->version = data & 0xF;
+		dev_info(ad714x->dev, "found AD7142 captouch, rev:%d\n",
+				ad714x->version);
+		return 0;
+	default:
+		dev_err(ad714x->dev,
+			"fail to detect AD714X captouch, read ID is %04x\n",
+			data);
+		return -ENODEV;
+	}
+}
+
+static void ad714x_hw_init(struct ad714x_chip *ad714x)
+{
+	int i, j;
+	unsigned short reg_base;
+	unsigned short data;
+
+	/* configuration CDC and interrupts*/
+
+	for (i = 0; i < STAGE_NUM; i++) {
+		reg_base = AD714X_STAGECFG_REG + i * STAGE_CFGREG_NUM;
+		for (j = 0; j < STAGE_CFGREG_NUM; j++)
+			ad714x->write(ad714x->dev, reg_base + j,
+					ad714x->hw->stage_cfg_reg[i][j]);
+	}
+
+	for (i = 0; i < SYS_CFGREG_NUM; i++)
+		ad714x->write(ad714x->dev, AD714X_SYSCFG_REG + i,
+			ad714x->hw->sys_cfg_reg[i]);
+	for (i = 0; i < SYS_CFGREG_NUM; i++)
+		ad714x->read(ad714x->dev, AD714X_SYSCFG_REG + i,
+			&data);
+
+	ad714x->write(ad714x->dev, AD714X_STG_CAL_EN_REG, 0xFFF);
+
+	/* clear all interrupts */
+	ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &data);
+	ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &data);
+	ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &data);
+}
+
+static irqreturn_t ad714x_interrupt_thread(int irq, void *data)
+{
+	struct ad714x_chip *ad714x = data;
+	int i;
+
+	mutex_lock(&ad714x->mutex);
+
+	ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &ad714x->l_state);
+	ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &ad714x->h_state);
+	ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &ad714x->c_state);
+
+	for (i = 0; i < ad714x->hw->button_num; i++)
+		ad714x_button_state_machine(ad714x, i);
+	for (i = 0; i < ad714x->hw->slider_num; i++)
+		ad714x_slider_state_machine(ad714x, i);
+	for (i = 0; i < ad714x->hw->wheel_num; i++)
+		ad714x_wheel_state_machine(ad714x, i);
+	for (i = 0; i < ad714x->hw->touchpad_num; i++)
+		ad714x_touchpad_state_machine(ad714x, i);
+
+	mutex_unlock(&ad714x->mutex);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ad714x_interrupt(int irq, void *data)
+{
+	return IRQ_WAKE_THREAD;
+}
+
+#define MAX_DEVICE_NUM 8
+int ad714x_probe(struct ad714x_chip **pad714x, struct device *dev,
+	u16 bus_type, int irq, ad714x_read_t read, ad714x_write_t write)
+{
+	int ret, i, alloc_idx;
+	struct input_dev *input[MAX_DEVICE_NUM];
+
+	struct ad714x_platform_data *plat_data;
+	struct ad714x_chip *ad714x;
+	void *drv_mem;
+
+	struct ad714x_button_drv *bt_drv;
+	struct ad714x_slider_drv *sd_drv;
+	struct ad714x_wheel_drv *wl_drv;
+	struct ad714x_touchpad_drv *tp_drv;
+
+	plat_data = dev->platform_data;
+	if (dev->platform_data == NULL) {
+		dev_err(dev, "platform data for ad714x doesn't exist\n");
+		return -ENODEV;
+	}
+
+	*pad714x = ad714x = kzalloc(sizeof(*ad714x) + sizeof(*ad714x->sw) +
+			sizeof(*sd_drv) * plat_data->slider_num +
+			sizeof(*wl_drv) * plat_data->wheel_num +
+			sizeof(*tp_drv) * plat_data->touchpad_num +
+			sizeof(*bt_drv) * plat_data->button_num, GFP_KERNEL);
+	if (!ad714x)
+		return -ENOMEM;
+	ad714x->hw = plat_data;
+
+	drv_mem = ad714x + 1;
+	ad714x->sw = drv_mem;
+	drv_mem += sizeof(*ad714x->sw);
+	ad714x->sw->slider = sd_drv = drv_mem;
+	drv_mem += sizeof(*sd_drv) * ad714x->hw->slider_num;
+	ad714x->sw->wheel = wl_drv = drv_mem;
+	drv_mem += sizeof(*wl_drv) * ad714x->hw->wheel_num;
+	ad714x->sw->touchpad = tp_drv = drv_mem;
+	drv_mem += sizeof(*tp_drv) * ad714x->hw->touchpad_num;
+	ad714x->sw->button = bt_drv = drv_mem;
+	drv_mem += sizeof(*bt_drv) * ad714x->hw->button_num;
+
+	ad714x->read = read;
+	ad714x->write = write;
+	ad714x->irq = irq;
+	ad714x->dev = dev;
+
+	ret = ad714x_hw_detect(ad714x);
+	if (ret)
+		goto det_err;
+
+	/* initilize and request sw/hw resources */
+
+	ad714x_hw_init(ad714x);
+	mutex_init(&ad714x->mutex);
+
+	if (ad714x->irq > 0) {
+		ret = request_threaded_irq(ad714x->irq, ad714x_interrupt,
+				ad714x_interrupt_thread, IRQF_TRIGGER_FALLING,
+				"ad714x_captouch", ad714x);
+		if (ret) {
+			dev_err(dev, "can't allocate irq %d\n",
+					ad714x->irq);
+			goto fail_irq;
+		}
+	} else {
+		dev_err(dev, "IRQ not configured!\n");
+		ret = -EINVAL;
+		goto det_err;
+	}
+
+	/*
+	 * Allocate and register AD714X input device
+	 */
+	alloc_idx = 0;
+
+	/* a slider uses one input_dev instance */
+	if (ad714x->hw->slider_num > 0) {
+		struct ad714x_slider_plat *sd_plat = ad714x->hw->slider;
+
+		for (i = 0; i < ad714x->hw->slider_num; i++) {
+			sd_drv[i].input = input[alloc_idx] = input_allocate_device();
+			if (!input[alloc_idx]) {
+				ret = -ENOMEM;
+				goto fail_alloc_reg;
+			}
+
+			__set_bit(EV_ABS, input[alloc_idx]->evbit);
+			__set_bit(EV_KEY, input[alloc_idx]->evbit);
+			__set_bit(ABS_X, input[alloc_idx]->absbit);
+			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
+			input_set_abs_params(input[alloc_idx], ABS_X, 0,
+					sd_plat->max_coord, 0, 0);
+
+			input[alloc_idx]->id.bustype = bus_type;
+			input[alloc_idx]->id.product = ad714x->product;
+			input[alloc_idx]->id.version = ad714x->version;
+
+			ret = input_register_device(input[alloc_idx]);
+			if (ret)
+				goto fail_alloc_reg;
+
+			alloc_idx++;
+		}
+	}
+
+	/* a wheel uses one input_dev instance */
+	if (ad714x->hw->wheel_num > 0) {
+		struct ad714x_wheel_plat *wl_plat = ad714x->hw->wheel;
+
+		for (i = 0; i < ad714x->hw->wheel_num; i++) {
+			wl_drv[i].input = input[alloc_idx] = input_allocate_device();
+			if (!input[alloc_idx]) {
+				ret = -ENOMEM;
+				goto fail_alloc_reg;
+			}
+
+			__set_bit(EV_KEY, input[alloc_idx]->evbit);
+			__set_bit(EV_ABS, input[alloc_idx]->evbit);
+			__set_bit(ABS_WHEEL, input[alloc_idx]->absbit);
+			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
+			input_set_abs_params(input[alloc_idx], ABS_WHEEL, 0,
+					wl_plat->max_coord, 0, 0);
+
+			input[alloc_idx]->id.bustype = bus_type;
+			input[alloc_idx]->id.product = ad714x->product;
+			input[alloc_idx]->id.version = ad714x->version;
+
+			ret = input_register_device(input[alloc_idx]);
+			if (ret)
+				goto fail_alloc_reg;
+
+			alloc_idx++;
+		}
+	}
+
+	/* a touchpad uses one input_dev instance */
+	if (ad714x->hw->touchpad_num > 0) {
+		struct ad714x_touchpad_plat *tp_plat = ad714x->hw->touchpad;
+
+		for (i = 0; i < ad714x->hw->touchpad_num; i++) {
+			tp_drv[i].input = input[alloc_idx] = input_allocate_device();
+			if (!input[alloc_idx]) {
+				ret = -ENOMEM;
+				goto fail_alloc_reg;
+			}
+
+			__set_bit(EV_ABS, input[alloc_idx]->evbit);
+			__set_bit(EV_KEY, input[alloc_idx]->evbit);
+			__set_bit(ABS_X, input[alloc_idx]->absbit);
+			__set_bit(ABS_Y, input[alloc_idx]->absbit);
+			__set_bit(BTN_TOUCH, input[alloc_idx]->keybit);
+			input_set_abs_params(input[alloc_idx], ABS_X, 0,
+					tp_plat->x_max_coord, 0, 0);
+			input_set_abs_params(input[alloc_idx], ABS_Y, 0,
+					tp_plat->y_max_coord, 0, 0);
+
+			input[alloc_idx]->id.bustype = bus_type;
+			input[alloc_idx]->id.product = ad714x->product;
+			input[alloc_idx]->id.version = ad714x->version;
+
+			ret = input_register_device(input[alloc_idx]);
+			if (ret)
+				goto fail_alloc_reg;
+
+			alloc_idx++;
+		}
+	}
+
+	/* all buttons use one input node */
+	if (ad714x->hw->button_num > 0) {
+		struct ad714x_button_plat *bt_plat = ad714x->hw->button;
+
+		input[alloc_idx] = input_allocate_device();
+		if (!input[alloc_idx]) {
+			ret = -ENOMEM;
+			goto fail_alloc_reg;
+		}
+
+		__set_bit(EV_KEY, input[alloc_idx]->evbit);
+		for (i = 0; i < ad714x->hw->button_num; i++) {
+			bt_drv[i].input = input[alloc_idx];
+			__set_bit(bt_plat[i].keycode, input[alloc_idx]->keybit);
+		}
+
+		input[alloc_idx]->id.bustype = bus_type;
+		input[alloc_idx]->id.product = ad714x->product;
+		input[alloc_idx]->id.version = ad714x->version;
+
+		ret = input_register_device(input[alloc_idx]);
+		if (ret)
+			goto fail_alloc_reg;
+
+		alloc_idx++;
+	}
+
+
+	return 0;
+
+ fail_alloc_reg:
+	dev_err(dev, "failed to setup AD714x input device %i\n", alloc_idx);
+	for (i = 0; i < alloc_idx - 1; i++)
+		input_unregister_device(input[i]);
+	input_free_device(input[alloc_idx]);
+
+	free_irq(ad714x->irq, ad714x);
+ fail_irq:
+ det_err:
+	kfree(ad714x);
+	return ret;
+}
+EXPORT_SYMBOL(ad714x_probe);
+
+int ad714x_remove(struct ad714x_chip *ad714x)
+{
+	int i;
+
+	/* unregister and free all input devices */
+
+	for (i = 0; i < ad714x->hw->slider_num; i++)
+		input_unregister_device(ad714x->sw->slider[i].input);
+
+	for (i = 0; i < ad714x->hw->wheel_num; i++)
+		input_unregister_device(ad714x->sw->wheel[i].input);
+
+	for (i = 0; i < ad714x->hw->touchpad_num; i++)
+		input_unregister_device(ad714x->sw->touchpad[i].input);
+
+	if (ad714x->hw->button_num)
+		input_unregister_device(ad714x->sw->button[0].input);
+
+	free_irq(ad714x->irq, ad714x);
+
+	kfree(ad714x);
+
+	return 0;
+}
+EXPORT_SYMBOL(ad714x_remove);
+
+#ifdef CONFIG_PM
+int ad714x_disable(struct ad714x_chip *ad714x)
+{
+	unsigned short data;
+
+	dev_dbg(ad714x->dev, "%s enter\n", __func__);
+
+	mutex_lock(&ad714x->mutex);
+
+	data = ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL] | 0x3;
+	ad714x->write(ad714x->dev, AD714X_PWR_CTRL, data);
+
+	mutex_unlock(&ad714x->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(ad714x_disable);
+
+int ad714x_enable(struct ad714x_chip *ad714x)
+{
+	unsigned short data;
+
+	dev_dbg(ad714x->dev, "%s enter\n", __func__);
+
+	mutex_lock(&ad714x->mutex);
+
+	/* resume to non-shutdown mode */
+
+	ad714x->write(ad714x->dev, AD714X_PWR_CTRL,
+			ad714x->hw->sys_cfg_reg[AD714X_PWR_CTRL]);
+
+	/* make sure the interrupt output line is not low level after resume,
+	 * otherwise we will get no chance to enter falling-edge irq again
+	 */
+
+	ad714x->read(ad714x->dev, STG_LOW_INT_STA_REG, &data);
+	ad714x->read(ad714x->dev, STG_HIGH_INT_STA_REG, &data);
+	ad714x->read(ad714x->dev, STG_COM_INT_STA_REG, &data);
+
+	mutex_unlock(&ad714x->mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL(ad714x_enable);
+#endif
+
+MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor Driver");
+MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/input/misc/ad714x.h b/drivers/input/misc/ad714x.h
new file mode 100644
index 0000000..3fc5a16
--- /dev/null
+++ b/drivers/input/misc/ad714x.h
@@ -0,0 +1,25 @@ 
+/*
+ * AD714X CapTouch Programmable Controller driver (bus interfaces)
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef _AD714X_H_
+#define _AD714X_H_
+
+#include <linux/types.h>
+
+struct device;
+struct ad714x_chip;
+typedef int (ad714x_read_t) (struct device *, unsigned short, unsigned short *);
+typedef int (ad714x_write_t) (struct device *, unsigned short, unsigned short);
+
+int ad714x_disable(struct ad714x_chip *ad714x);
+int ad714x_enable(struct ad714x_chip *ad714x);
+int ad714x_probe(struct ad714x_chip **pad714x, struct device *dev,
+	u16 bus_type, int irq, ad714x_read_t read, ad714x_write_t write);
+int ad714x_remove(struct ad714x_chip *ad714x);
+
+#endif
diff --git a/include/linux/input.h b/include/linux/input.h
index 0ccfc30..8b38cfa 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -756,6 +756,7 @@  struct input_absinfo {
 #define BUS_HOST		0x19
 #define BUS_GSC			0x1A
 #define BUS_ATARI		0x1B
+#define BUS_SPI			0x1C
 
 /*
  * MT_TOOL types
diff --git a/include/linux/input/ad714x.h b/include/linux/input/ad714x.h
new file mode 100644
index 0000000..0cbe5e8
--- /dev/null
+++ b/include/linux/input/ad714x.h
@@ -0,0 +1,63 @@ 
+/*
+ * include/linux/input/ad714x.h
+ *
+ * AD714x is very flexible, it can be used as buttons, scrollwheel,
+ * slider, touchpad at the same time. That depends on the boards.
+ * The platform_data for the device's "struct device" holds this
+ * information.
+ *
+ * Copyright 2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __LINUX_INPUT_AD714X_H__
+#define __LINUX_INPUT_AD714X_H__
+
+#define STAGE_NUM              12
+#define STAGE_CFGREG_NUM       8
+#define SYS_CFGREG_NUM         8
+
+/* board information which need be initialized in arch/mach... */
+struct ad714x_slider_plat {
+	int start_stage;
+	int end_stage;
+	int max_coord;
+};
+
+struct ad714x_wheel_plat {
+	int start_stage;
+	int end_stage;
+	int max_coord;
+};
+
+struct ad714x_touchpad_plat {
+	int x_start_stage;
+	int x_end_stage;
+	int x_max_coord;
+
+	int y_start_stage;
+	int y_end_stage;
+	int y_max_coord;
+};
+
+struct ad714x_button_plat {
+	int keycode;
+	unsigned short l_mask;
+	unsigned short h_mask;
+};
+
+struct ad714x_platform_data {
+	int slider_num;
+	int wheel_num;
+	int touchpad_num;
+	int button_num;
+	struct ad714x_slider_plat *slider;
+	struct ad714x_wheel_plat *wheel;
+	struct ad714x_touchpad_plat *touchpad;
+	struct ad714x_button_plat *button;
+	unsigned short stage_cfg_reg[STAGE_NUM][STAGE_CFGREG_NUM];
+	unsigned short sys_cfg_reg[SYS_CFGREG_NUM];
+};
+
+#endif