[deliverable/linux.git] / drivers / input / touchscreen / ad7879.c

/*
 * AD7879/AD7889 based touchscreen and GPIO driver
 *
 * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 *
 * History:
 * Copyright (c) 2005 David Brownell
 * Copyright (c) 2006 Nokia Corporation
 * Various changes: Imre Deak <imre.deak@nokia.com>
 *
 * Using code from:
 *  - corgi_ts.c
 *	Copyright (C) 2004-2005 Richard Purdie
 *  - omap_ts.[hc], ads7846.h, ts_osk.c
 *	Copyright (C) 2002 MontaVista Software
 *	Copyright (C) 2004 Texas Instruments
 *	Copyright (C) 2005 Dirk Behme
 *  - ad7877.c
 *	Copyright (C) 2006-2008 Analog Devices Inc.
 */

#include <linux/device.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/gpio.h>

#include <linux/spi/ad7879.h>
#include "ad7879.h"

#define AD7879_REG_ZEROS		0
#define AD7879_REG_CTRL1		1
#define AD7879_REG_CTRL2		2
#define AD7879_REG_CTRL3		3
#define AD7879_REG_AUX1HIGH		4
#define AD7879_REG_AUX1LOW		5
#define AD7879_REG_TEMP1HIGH		6
#define AD7879_REG_TEMP1LOW		7
#define AD7879_REG_XPLUS		8
#define AD7879_REG_YPLUS		9
#define AD7879_REG_Z1			10
#define AD7879_REG_Z2			11
#define AD7879_REG_AUXVBAT		12
#define AD7879_REG_TEMP			13
#define AD7879_REG_REVID		14

/* Control REG 1 */
#define AD7879_TMR(x)			((x & 0xFF) << 0)
#define AD7879_ACQ(x)			((x & 0x3) << 8)
#define AD7879_MODE_NOC			(0 << 10)	/* Do not convert */
#define AD7879_MODE_SCC			(1 << 10)	/* Single channel conversion */
#define AD7879_MODE_SEQ0		(2 << 10)	/* Sequence 0 in Slave Mode */
#define AD7879_MODE_SEQ1		(3 << 10)	/* Sequence 1 in Master Mode */
#define AD7879_MODE_INT			(1 << 15)	/* PENIRQ disabled INT enabled */

/* Control REG 2 */
#define AD7879_FCD(x)			((x & 0x3) << 0)
#define AD7879_RESET			(1 << 4)
#define AD7879_MFS(x)			((x & 0x3) << 5)
#define AD7879_AVG(x)			((x & 0x3) << 7)
#define	AD7879_SER			(1 << 9)	/* non-differential */
#define	AD7879_DFR			(0 << 9)	/* differential */
#define AD7879_GPIOPOL			(1 << 10)
#define AD7879_GPIODIR			(1 << 11)
#define AD7879_GPIO_DATA		(1 << 12)
#define AD7879_GPIO_EN			(1 << 13)
#define AD7879_PM(x)			((x & 0x3) << 14)
#define AD7879_PM_SHUTDOWN		(0)
#define AD7879_PM_DYN			(1)
#define AD7879_PM_FULLON		(2)

/* Control REG 3 */
#define AD7879_TEMPMASK_BIT		(1<<15)
#define AD7879_AUXVBATMASK_BIT		(1<<14)
#define AD7879_INTMODE_BIT		(1<<13)
#define AD7879_GPIOALERTMASK_BIT	(1<<12)
#define AD7879_AUXLOW_BIT		(1<<11)
#define AD7879_AUXHIGH_BIT		(1<<10)
#define AD7879_TEMPLOW_BIT		(1<<9)
#define AD7879_TEMPHIGH_BIT		(1<<8)
#define AD7879_YPLUS_BIT		(1<<7)
#define AD7879_XPLUS_BIT		(1<<6)
#define AD7879_Z1_BIT			(1<<5)
#define AD7879_Z2_BIT			(1<<4)
#define AD7879_AUX_BIT			(1<<3)
#define AD7879_VBAT_BIT			(1<<2)
#define AD7879_TEMP_BIT			(1<<1)

enum {
	AD7879_SEQ_XPOS  = 0,
	AD7879_SEQ_YPOS  = 1,
	AD7879_SEQ_Z1    = 2,
	AD7879_SEQ_Z2    = 3,
	AD7879_NR_SENSE  = 4,
};

#define	MAX_12BIT			((1<<12)-1)
#define	TS_PEN_UP_TIMEOUT		msecs_to_jiffies(50)

struct ad7879 {
	const struct ad7879_bus_ops *bops;

	struct device		*dev;
	struct input_dev	*input;
	struct timer_list	timer;
#ifdef CONFIG_GPIOLIB
	struct gpio_chip	gc;
	struct mutex		mutex;
#endif
	unsigned int		irq;
	bool			disabled;	/* P: input->mutex */
	bool			suspended;	/* P: input->mutex */
	u16			conversion_data[AD7879_NR_SENSE];
	char			phys[32];
	u8			first_conversion_delay;
	u8			acquisition_time;
	u8			averaging;
	u8			pen_down_acc_interval;
	u8			median;
	u16			x_plate_ohms;
	u16			pressure_max;
	u16			cmd_crtl1;
	u16			cmd_crtl2;
	u16			cmd_crtl3;
};

static int ad7879_read(struct ad7879 *ts, u8 reg)
{
	return ts->bops->read(ts->dev, reg);
}

static int ad7879_multi_read(struct ad7879 *ts, u8 first_reg, u8 count, u16 *buf)
{
	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
}

static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
{
	return ts->bops->write(ts->dev, reg, val);
}

static int ad7879_report(struct ad7879 *ts)
{
	struct input_dev *input_dev = ts->input;
	unsigned Rt;
	u16 x, y, z1, z2;

	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;

	/*
	 * The samples processed here are already preprocessed by the AD7879.
	 * The preprocessing function consists of a median and an averaging
	 * filter.  The combination of these two techniques provides a robust
	 * solution, discarding the spurious noise in the signal and keeping
	 * only the data of interest.  The size of both filters is
	 * programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
	 * user-programmable conversion controls include variable acquisition
	 * time, and first conversion delay. Up to 16 averages can be taken
	 * per conversion.
	 */

	if (likely(x && z1)) {
		/* compute touch pressure resistance using equation #1 */
		Rt = (z2 - z1) * x * ts->x_plate_ohms;
		Rt /= z1;
		Rt = (Rt + 2047) >> 12;

		if (!timer_pending(&ts->timer))
			input_report_key(input_dev, BTN_TOUCH, 1);

		input_report_abs(input_dev, ABS_X, x);
		input_report_abs(input_dev, ABS_Y, y);
		input_report_abs(input_dev, ABS_PRESSURE, Rt);
		input_sync(input_dev);
		return 0;
	}

	return -EINVAL;
}

static void ad7879_ts_event_release(struct ad7879 *ts)
{
	struct input_dev *input_dev = ts->input;

	input_report_abs(input_dev, ABS_PRESSURE, 0);
	input_report_key(input_dev, BTN_TOUCH, 0);
	input_sync(input_dev);
}

static void ad7879_timer(unsigned long handle)
{
	struct ad7879 *ts = (void *)handle;

	ad7879_ts_event_release(ts);
}

static irqreturn_t ad7879_irq(int irq, void *handle)
{
	struct ad7879 *ts = handle;

	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);

	if (!ad7879_report(ts))
		mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);

	return IRQ_HANDLED;
}

static void __ad7879_enable(struct ad7879 *ts)
{
	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);

	enable_irq(ts->irq);
}

static void __ad7879_disable(struct ad7879 *ts)
{
	disable_irq(ts->irq);

	if (del_timer_sync(&ts->timer))
		ad7879_ts_event_release(ts);

	ad7879_write(ts, AD7879_REG_CTRL2, AD7879_PM(AD7879_PM_SHUTDOWN));
}


static int ad7879_open(struct input_dev *input)
{
	struct ad7879 *ts = input_get_drvdata(input);

	/* protected by input->mutex */
	if (!ts->disabled && !ts->suspended)
		__ad7879_enable(ts);

	return 0;
}

static void ad7879_close(struct input_dev* input)
{
	struct ad7879 *ts = input_get_drvdata(input);

	/* protected by input->mutex */
	if (!ts->disabled && !ts->suspended)
		__ad7879_disable(ts);
}

void ad7879_suspend(struct ad7879 *ts)
{
	mutex_lock(&ts->input->mutex);

	if (!ts->suspended && !ts->disabled && ts->input->users)
		__ad7879_disable(ts);

	ts->suspended = true;

	mutex_unlock(&ts->input->mutex);
}
EXPORT_SYMBOL(ad7879_suspend);

void ad7879_resume(struct ad7879 *ts)
{
	mutex_lock(&ts->input->mutex);

	if (ts->suspended && !ts->disabled && ts->input->users)
		__ad7879_enable(ts);

	ts->suspended = false;

	mutex_unlock(&ts->input->mutex);
}
EXPORT_SYMBOL(ad7879_resume);

static void ad7879_toggle(struct ad7879 *ts, bool disable)
{
	mutex_lock(&ts->input->mutex);

	if (!ts->suspended && ts->input->users != 0) {

		if (disable) {
			if (ts->disabled)
				__ad7879_enable(ts);
		} else {
			if (!ts->disabled)
				__ad7879_disable(ts);
		}
	}

	ts->disabled = disable;

	mutex_unlock(&ts->input->mutex);
}

static ssize_t ad7879_disable_show(struct device *dev,
				     struct device_attribute *attr, char *buf)
{
	struct ad7879 *ts = dev_get_drvdata(dev);

	return sprintf(buf, "%u\n", ts->disabled);
}

static ssize_t ad7879_disable_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	struct ad7879 *ts = dev_get_drvdata(dev);
	unsigned long val;
	int error;

	error = strict_strtoul(buf, 10, &val);
	if (error)
		return error;

	ad7879_toggle(ts, val);

	return count;
}

static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);

static struct attribute *ad7879_attributes[] = {
	&dev_attr_disable.attr,
	NULL
};

static const struct attribute_group ad7879_attr_group = {
	.attrs = ad7879_attributes,
};

#ifdef CONFIG_GPIOLIB
static int ad7879_gpio_direction_input(struct gpio_chip *chip,
					unsigned gpio)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	int err;

	mutex_lock(&ts->mutex);
	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIODIR | AD7879_GPIOPOL;
	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);

	return err;
}

static int ad7879_gpio_direction_output(struct gpio_chip *chip,
					unsigned gpio, int level)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	int err;

	mutex_lock(&ts->mutex);
	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
	ts->cmd_crtl2 |= AD7879_GPIO_EN | AD7879_GPIOPOL;
	if (level)
		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
	else
		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);

	return err;
}

static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	u16 val;

	mutex_lock(&ts->mutex);
	val = ad7879_read(ts, AD7879_REG_CTRL2);
	mutex_unlock(&ts->mutex);

	return !!(val & AD7879_GPIO_DATA);
}

static void ad7879_gpio_set_value(struct gpio_chip *chip,
				  unsigned gpio, int value)
{
	struct ad7879 *ts = container_of(chip, struct ad7879, gc);

	mutex_lock(&ts->mutex);
	if (value)
		ts->cmd_crtl2 |= AD7879_GPIO_DATA;
	else
		ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;

	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	mutex_unlock(&ts->mutex);
}

static int ad7879_gpio_add(struct ad7879 *ts,
			   const struct ad7879_platform_data *pdata)
{
	int ret = 0;

	mutex_init(&ts->mutex);

	if (pdata->gpio_export) {
		ts->gc.direction_input = ad7879_gpio_direction_input;
		ts->gc.direction_output = ad7879_gpio_direction_output;
		ts->gc.get = ad7879_gpio_get_value;
		ts->gc.set = ad7879_gpio_set_value;
		ts->gc.can_sleep = 1;
		ts->gc.base = pdata->gpio_base;
		ts->gc.ngpio = 1;
		ts->gc.label = "AD7879-GPIO";
		ts->gc.owner = THIS_MODULE;
		ts->gc.dev = ts->dev;

		ret = gpiochip_add(&ts->gc);
		if (ret)
			dev_err(ts->dev, "failed to register gpio %d\n",
				ts->gc.base);
	}

	return ret;
}

static void ad7879_gpio_remove(struct ad7879 *ts)
{
	const struct ad7879_platform_data *pdata = ts->dev->platform_data;
	int ret;

	if (pdata->gpio_export) {
		ret = gpiochip_remove(&ts->gc);
		if (ret)
			dev_err(ts->dev, "failed to remove gpio %d\n",
				ts->gc.base);
	}
}
#else
static inline int ad7879_gpio_add(struct ad7879 *ts,
				  const struct ad7879_platform_data *pdata)
{
	return 0;
}

static inline void ad7879_gpio_remove(struct ad7879 *ts)
{
}
#endif

struct ad7879 *ad7879_probe(struct device *dev, u8 devid, unsigned int irq,
			    const struct ad7879_bus_ops *bops)
{
	struct ad7879_platform_data *pdata = dev->platform_data;
	struct ad7879 *ts;
	struct input_dev *input_dev;
	int err;
	u16 revid;

	if (!irq) {
		dev_err(dev, "no IRQ?\n");
		err = -EINVAL;
		goto err_out;
	}

	if (!pdata) {
		dev_err(dev, "no platform data?\n");
		err = -EINVAL;
		goto err_out;
	}

	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
	input_dev = input_allocate_device();
	if (!ts || !input_dev) {
		err = -ENOMEM;
		goto err_free_mem;
	}

	ts->bops = bops;
	ts->dev = dev;
	ts->input = input_dev;
	ts->irq = irq;

	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);

	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
	ts->pressure_max = pdata->pressure_max ? : ~0;

	ts->first_conversion_delay = pdata->first_conversion_delay;
	ts->acquisition_time = pdata->acquisition_time;
	ts->averaging = pdata->averaging;
	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
	ts->median = pdata->median;

	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));

	input_dev->name = "AD7879 Touchscreen";
	input_dev->phys = ts->phys;
	input_dev->dev.parent = dev;
	input_dev->id.bustype = bops->bustype;

	input_dev->open = ad7879_open;
	input_dev->close = ad7879_close;

	input_set_drvdata(input_dev, ts);

	__set_bit(EV_ABS, input_dev->evbit);
	__set_bit(ABS_X, input_dev->absbit);
	__set_bit(ABS_Y, input_dev->absbit);
	__set_bit(ABS_PRESSURE, input_dev->absbit);

	__set_bit(EV_KEY, input_dev->evbit);
	__set_bit(BTN_TOUCH, input_dev->keybit);

	input_set_abs_params(input_dev, ABS_X,
			pdata->x_min ? : 0,
			pdata->x_max ? : MAX_12BIT,
			0, 0);
	input_set_abs_params(input_dev, ABS_Y,
			pdata->y_min ? : 0,
			pdata->y_max ? : MAX_12BIT,
			0, 0);
	input_set_abs_params(input_dev, ABS_PRESSURE,
			pdata->pressure_min, pdata->pressure_max, 0, 0);

	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
	if (err < 0) {
		dev_err(dev, "Failed to write %s\n", input_dev->name);
		goto err_free_mem;
	}

	revid = ad7879_read(ts, AD7879_REG_REVID);
	input_dev->id.product = (revid & 0xff);
	input_dev->id.version = revid >> 8;
	if (input_dev->id.product != devid) {
		dev_err(dev, "Failed to probe %s (%x vs %x)\n",
			input_dev->name, devid, revid);
		err = -ENODEV;
		goto err_free_mem;
	}

	ts->cmd_crtl3 = AD7879_YPLUS_BIT |
			AD7879_XPLUS_BIT |
			AD7879_Z2_BIT |
			AD7879_Z1_BIT |
			AD7879_TEMPMASK_BIT |
			AD7879_AUXVBATMASK_BIT |
			AD7879_GPIOALERTMASK_BIT;

	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) | AD7879_DFR |
			AD7879_AVG(ts->averaging) |
			AD7879_MFS(ts->median) |
			AD7879_FCD(ts->first_conversion_delay);

	ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
			AD7879_ACQ(ts->acquisition_time) |
			AD7879_TMR(ts->pen_down_acc_interval);

	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
				   IRQF_TRIGGER_FALLING,
				   dev_name(dev), ts);
	if (err) {
		dev_err(dev, "irq %d busy?\n", ts->irq);
		goto err_free_mem;
	}

	__ad7879_disable(ts);

	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
	if (err)
		goto err_free_irq;

	err = ad7879_gpio_add(ts, pdata);
	if (err)
		goto err_remove_attr;

	err = input_register_device(input_dev);
	if (err)
		goto err_remove_gpio;

	return ts;

err_remove_gpio:
	ad7879_gpio_remove(ts);
err_remove_attr:
	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
err_free_irq:
	free_irq(ts->irq, ts);
err_free_mem:
	input_free_device(input_dev);
	kfree(ts);
err_out:
	return ERR_PTR(err);
}
EXPORT_SYMBOL(ad7879_probe);

void ad7879_remove(struct ad7879 *ts)
{
	ad7879_gpio_remove(ts);
	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
	free_irq(ts->irq, ts);
	input_unregister_device(ts->input);
	kfree(ts);
}
EXPORT_SYMBOL(ad7879_remove);

MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
b4be468c	1	/*
4397c98a	2	* AD7879/AD7889 based touchscreen and GPIO driver
b4be468c	3	*
4397c98a	4	* Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
b4be468c	5	*
4397c98a	6	* Licensed under the GPL-2 or later.
b4be468c MH	7	*
	8	* History:
	9	* Copyright (c) 2005 David Brownell
	10	* Copyright (c) 2006 Nokia Corporation
	11	* Various changes: Imre Deak <imre.deak@nokia.com>
	12	*
	13	* Using code from:
	14	* - corgi_ts.c
	15	* Copyright (C) 2004-2005 Richard Purdie
	16	* - omap_ts.[hc], ads7846.h, ts_osk.c
	17	* Copyright (C) 2002 MontaVista Software
	18	* Copyright (C) 2004 Texas Instruments
	19	* Copyright (C) 2005 Dirk Behme
	20	* - ad7877.c
	21	* Copyright (C) 2006-2008 Analog Devices Inc.
	22	*/
	23
	24	#include <linux/device.h>
	25	#include <linux/init.h>
	26	#include <linux/delay.h>
	27	#include <linux/input.h>
	28	#include <linux/interrupt.h>
	29	#include <linux/irq.h>
	30	#include <linux/slab.h>
b4be468c MH	31	#include <linux/spi/spi.h>
b4be468c MH	32	#include <linux/i2c.h>
ec51b7f5	33	#include <linux/gpio.h>
b4be468c MH	34
b4be468c MH	35	#include <linux/spi/ad7879.h>
4397c98a	36	#include "ad7879.h"
b4be468c MH	37
	38	#define AD7879_REG_ZEROS 0
	39	#define AD7879_REG_CTRL1 1
	40	#define AD7879_REG_CTRL2 2
	41	#define AD7879_REG_CTRL3 3
	42	#define AD7879_REG_AUX1HIGH 4
	43	#define AD7879_REG_AUX1LOW 5
	44	#define AD7879_REG_TEMP1HIGH 6
	45	#define AD7879_REG_TEMP1LOW 7
	46	#define AD7879_REG_XPLUS 8
	47	#define AD7879_REG_YPLUS 9
	48	#define AD7879_REG_Z1 10
	49	#define AD7879_REG_Z2 11
	50	#define AD7879_REG_AUXVBAT 12
	51	#define AD7879_REG_TEMP 13
	52	#define AD7879_REG_REVID 14
	53
	54	/* Control REG 1 */
	55	#define AD7879_TMR(x) ((x & 0xFF) << 0)
	56	#define AD7879_ACQ(x) ((x & 0x3) << 8)
	57	#define AD7879_MODE_NOC (0 << 10) /* Do not convert */
	58	#define AD7879_MODE_SCC (1 << 10) /* Single channel conversion */
	59	#define AD7879_MODE_SEQ0 (2 << 10) /* Sequence 0 in Slave Mode */
	60	#define AD7879_MODE_SEQ1 (3 << 10) /* Sequence 1 in Master Mode */
	61	#define AD7879_MODE_INT (1 << 15) /* PENIRQ disabled INT enabled */
	62
	63	/* Control REG 2 */
	64	#define AD7879_FCD(x) ((x & 0x3) << 0)
	65	#define AD7879_RESET (1 << 4)
	66	#define AD7879_MFS(x) ((x & 0x3) << 5)
	67	#define AD7879_AVG(x) ((x & 0x3) << 7)
	68	#define AD7879_SER (1 << 9) /* non-differential */
	69	#define AD7879_DFR (0 << 9) /* differential */
	70	#define AD7879_GPIOPOL (1 << 10)
	71	#define AD7879_GPIODIR (1 << 11)
	72	#define AD7879_GPIO_DATA (1 << 12)
	73	#define AD7879_GPIO_EN (1 << 13)
	74	#define AD7879_PM(x) ((x & 0x3) << 14)
	75	#define AD7879_PM_SHUTDOWN (0)
	76	#define AD7879_PM_DYN (1)
	77	#define AD7879_PM_FULLON (2)
	78
	79	/* Control REG 3 */
	80	#define AD7879_TEMPMASK_BIT (1<<15)
	81	#define AD7879_AUXVBATMASK_BIT (1<<14)
	82	#define AD7879_INTMODE_BIT (1<<13)
	83	#define AD7879_GPIOALERTMASK_BIT (1<<12)
	84	#define AD7879_AUXLOW_BIT (1<<11)
	85	#define AD7879_AUXHIGH_BIT (1<<10)
	86	#define AD7879_TEMPLOW_BIT (1<<9)
	87	#define AD7879_TEMPHIGH_BIT (1<<8)
	88	#define AD7879_YPLUS_BIT (1<<7)
	89	#define AD7879_XPLUS_BIT (1<<6)
	90	#define AD7879_Z1_BIT (1<<5)
	91	#define AD7879_Z2_BIT (1<<4)
	92	#define AD7879_AUX_BIT (1<<3)
	93	#define AD7879_VBAT_BIT (1<<2)
	94	#define AD7879_TEMP_BIT (1<<1)
	95
	96	enum {
	97	AD7879_SEQ_XPOS = 0,
	98	AD7879_SEQ_YPOS = 1,
	99	AD7879_SEQ_Z1 = 2,
	100	AD7879_SEQ_Z2 = 3,
101	AD7879_NR_SENSE = 4,
102	};
103
104	#define MAX_12BIT ((1<<12)-1)
105	#define TS_PEN_UP_TIMEOUT msecs_to_jiffies(50)
106
b4be468c	107	struct ad7879 {
4397c98a MF	108	const struct ad7879_bus_ops *bops;
	109
	110	struct device *dev;
b4be468c	111	struct input_dev *input;
b4be468c	112	struct timer_list timer;
ec51b7f5 MH	113	#ifdef CONFIG_GPIOLIB
ec51b7f5 MH	114	struct gpio_chip gc;
14fbbc36	115	struct mutex mutex;
ec51b7f5	116	#endif
4397c98a	117	unsigned int irq;
14fbbc36 DT	118	bool disabled; /* P: input->mutex */
14fbbc36 DT	119	bool suspended; /* P: input->mutex */
b4be468c MH	120	u16 conversion_data[AD7879_NR_SENSE];
	121	char phys[32];
	122	u8 first_conversion_delay;
	123	u8 acquisition_time;
	124	u8 averaging;
	125	u8 pen_down_acc_interval;
	126	u8 median;
	127	u16 x_plate_ohms;
	128	u16 pressure_max;
b4be468c MH	129	u16 cmd_crtl1;
	130	u16 cmd_crtl2;
	131	u16 cmd_crtl3;
b4be468c MH	132	};
b4be468c MH	133
4397c98a MF	134	static int ad7879_read(struct ad7879 *ts, u8 reg)
	135	{
	136	return ts->bops->read(ts->dev, reg);
	137	}
	138
	139	static int ad7879_multi_read(struct ad7879 ts, u8 first_reg, u8 count, u16 buf)
	140	{
	141	return ts->bops->multi_read(ts->dev, first_reg, count, buf);
	142	}
	143
	144	static int ad7879_write(struct ad7879 *ts, u8 reg, u16 val)
	145	{
	146	return ts->bops->write(ts->dev, reg, val);
	147	}
b4be468c	148
963ce8ae	149	static int ad7879_report(struct ad7879 *ts)
b4be468c MH	150	{
	151	struct input_dev *input_dev = ts->input;
	152	unsigned Rt;
	153	u16 x, y, z1, z2;
	154
	155	x = ts->conversion_data[AD7879_SEQ_XPOS] & MAX_12BIT;
	156	y = ts->conversion_data[AD7879_SEQ_YPOS] & MAX_12BIT;
	157	z1 = ts->conversion_data[AD7879_SEQ_Z1] & MAX_12BIT;
	158	z2 = ts->conversion_data[AD7879_SEQ_Z2] & MAX_12BIT;
	159
	160	/*
	161	* The samples processed here are already preprocessed by the AD7879.
4397c98a MF	162	* The preprocessing function consists of a median and an averaging
	163	* filter. The combination of these two techniques provides a robust
	164	* solution, discarding the spurious noise in the signal and keeping
	165	* only the data of interest. The size of both filters is
	166	* programmable. (dev.platform_data, see linux/spi/ad7879.h) Other
	167	* user-programmable conversion controls include variable acquisition
	168	* time, and first conversion delay. Up to 16 averages can be taken
	169	* per conversion.
b4be468c MH	170	*/
	171
	172	if (likely(x && z1)) {
	173	/* compute touch pressure resistance using equation #1 */
	174	Rt = (z2 - z1) * x * ts->x_plate_ohms;
	175	Rt /= z1;
	176	Rt = (Rt + 2047) >> 12;
	177
963ce8ae MH	178	if (!timer_pending(&ts->timer))
	179	input_report_key(input_dev, BTN_TOUCH, 1);
	180
b4be468c MH	181	input_report_abs(input_dev, ABS_X, x);
	182	input_report_abs(input_dev, ABS_Y, y);
	183	input_report_abs(input_dev, ABS_PRESSURE, Rt);
	184	input_sync(input_dev);
963ce8ae	185	return 0;
b4be468c	186	}
963ce8ae MH	187
963ce8ae MH	188	return -EINVAL;
b4be468c MH	189	}
b4be468c MH	190
b4be468c MH	191	static void ad7879_ts_event_release(struct ad7879 *ts)
	192	{
	193	struct input_dev *input_dev = ts->input;
	194
	195	input_report_abs(input_dev, ABS_PRESSURE, 0);
963ce8ae	196	input_report_key(input_dev, BTN_TOUCH, 0);
b4be468c MH	197	input_sync(input_dev);
	198	}
	199
	200	static void ad7879_timer(unsigned long handle)
	201	{
	202	struct ad7879 ts = (void )handle;
	203
	204	ad7879_ts_event_release(ts);
	205	}
	206
	207	static irqreturn_t ad7879_irq(int irq, void *handle)
	208	{
	209	struct ad7879 *ts = handle;
	210
4397c98a	211	ad7879_multi_read(ts, AD7879_REG_XPLUS, AD7879_NR_SENSE, ts->conversion_data);
b4be468c	212
963ce8ae MH	213	if (!ad7879_report(ts))
963ce8ae MH	214	mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
b4be468c MH	215
	216	return IRQ_HANDLED;
	217	}
	218
14fbbc36	219	static void __ad7879_enable(struct ad7879 *ts)
b4be468c	220	{
4397c98a MF	221	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
	222	ad7879_write(ts, AD7879_REG_CTRL3, ts->cmd_crtl3);
	223	ad7879_write(ts, AD7879_REG_CTRL1, ts->cmd_crtl1);
14fbbc36 DT	224
14fbbc36 DT	225	enable_irq(ts->irq);
b4be468c MH	226	}
b4be468c MH	227
14fbbc36	228	static void __ad7879_disable(struct ad7879 *ts)
b4be468c	229	{
14fbbc36	230	disable_irq(ts->irq);
b4be468c	231
14fbbc36 DT	232	if (del_timer_sync(&ts->timer))
14fbbc36 DT	233	ad7879_ts_event_release(ts);
b4be468c	234
14fbbc36 DT	235	ad7879_write(ts, AD7879_REG_CTRL2, AD7879_PM(AD7879_PM_SHUTDOWN));
14fbbc36 DT	236	}
b4be468c	237
b4be468c	238
14fbbc36 DT	239	static int ad7879_open(struct input_dev *input)
	240	{
	241	struct ad7879 *ts = input_get_drvdata(input);
b4be468c	242
14fbbc36 DT	243	/* protected by input->mutex */
	244	if (!ts->disabled && !ts->suspended)
	245	__ad7879_enable(ts);
	246
	247	return 0;
b4be468c MH	248	}
b4be468c MH	249
14fbbc36	250	static void ad7879_close(struct input_dev* input)
b4be468c	251	{
14fbbc36 DT	252	struct ad7879 *ts = input_get_drvdata(input);
	253
	254	/* protected by input->mutex */
	255	if (!ts->disabled && !ts->suspended)
	256	__ad7879_disable(ts);
	257	}
	258
	259	void ad7879_suspend(struct ad7879 *ts)
	260	{
	261	mutex_lock(&ts->input->mutex);
	262
	263	if (!ts->suspended && !ts->disabled && ts->input->users)
	264	__ad7879_disable(ts);
	265
	266	ts->suspended = true;
	267
	268	mutex_unlock(&ts->input->mutex);
	269	}
	270	EXPORT_SYMBOL(ad7879_suspend);
	271
	272	void ad7879_resume(struct ad7879 *ts)
	273	{
	274	mutex_lock(&ts->input->mutex);
b4be468c	275
14fbbc36 DT	276	if (ts->suspended && !ts->disabled && ts->input->users)
	277	__ad7879_enable(ts);
	278
	279	ts->suspended = false;
	280
	281	mutex_unlock(&ts->input->mutex);
	282	}
	283	EXPORT_SYMBOL(ad7879_resume);
	284
	285	static void ad7879_toggle(struct ad7879 *ts, bool disable)
	286	{
	287	mutex_lock(&ts->input->mutex);
	288
	289	if (!ts->suspended && ts->input->users != 0) {
	290
	291	if (disable) {
	292	if (ts->disabled)
	293	__ad7879_enable(ts);
	294	} else {
	295	if (!ts->disabled)
	296	__ad7879_disable(ts);
	297	}
b4be468c MH	298	}
b4be468c MH	299
14fbbc36 DT	300	ts->disabled = disable;
	301
	302	mutex_unlock(&ts->input->mutex);
b4be468c MH	303	}
	304
	305	static ssize_t ad7879_disable_show(struct device *dev,
	306	struct device_attribute attr, char buf)
	307	{
	308	struct ad7879 *ts = dev_get_drvdata(dev);
	309
	310	return sprintf(buf, "%u\n", ts->disabled);
	311	}
	312
	313	static ssize_t ad7879_disable_store(struct device *dev,
	314	struct device_attribute *attr,
	315	const char *buf, size_t count)
	316	{
	317	struct ad7879 *ts = dev_get_drvdata(dev);
	318	unsigned long val;
	319	int error;
	320
	321	error = strict_strtoul(buf, 10, &val);
	322	if (error)
	323	return error;
	324
14fbbc36	325	ad7879_toggle(ts, val);
b4be468c MH	326
	327	return count;
	328	}
	329
	330	static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
	331
ec51b7f5 MH	332	static struct attribute *ad7879_attributes[] = {
	333	&dev_attr_disable.attr,
	334	NULL
	335	};
	336
	337	static const struct attribute_group ad7879_attr_group = {
	338	.attrs = ad7879_attributes,
	339	};
	340
	341	#ifdef CONFIG_GPIOLIB
	342	static int ad7879_gpio_direction_input(struct gpio_chip *chip,
	343	unsigned gpio)
b4be468c	344	{
ec51b7f5 MH	345	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
ec51b7f5 MH	346	int err;
b4be468c	347
ec51b7f5 MH	348	mutex_lock(&ts->mutex);
ec51b7f5 MH	349	ts->cmd_crtl2 \|= AD7879_GPIO_EN \| AD7879_GPIODIR \| AD7879_GPIOPOL;
4397c98a	350	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
ec51b7f5 MH	351	mutex_unlock(&ts->mutex);
	352
	353	return err;
b4be468c MH	354	}
b4be468c MH	355
ec51b7f5 MH	356	static int ad7879_gpio_direction_output(struct gpio_chip *chip,
ec51b7f5 MH	357	unsigned gpio, int level)
b4be468c	358	{
ec51b7f5 MH	359	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
ec51b7f5 MH	360	int err;
b4be468c	361
ec51b7f5 MH	362	mutex_lock(&ts->mutex);
	363	ts->cmd_crtl2 &= ~AD7879_GPIODIR;
	364	ts->cmd_crtl2 \|= AD7879_GPIO_EN \| AD7879_GPIOPOL;
	365	if (level)
	366	ts->cmd_crtl2 \|= AD7879_GPIO_DATA;
	367	else
	368	ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
	369
4397c98a	370	err = ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
ec51b7f5 MH	371	mutex_unlock(&ts->mutex);
	372
	373	return err;
	374	}
	375
	376	static int ad7879_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
	377	{
	378	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
	379	u16 val;
b4be468c MH	380
b4be468c MH	381	mutex_lock(&ts->mutex);
4397c98a	382	val = ad7879_read(ts, AD7879_REG_CTRL2);
b4be468c MH	383	mutex_unlock(&ts->mutex);
b4be468c MH	384
ec51b7f5	385	return !!(val & AD7879_GPIO_DATA);
b4be468c MH	386	}
b4be468c MH	387
ec51b7f5 MH	388	static void ad7879_gpio_set_value(struct gpio_chip *chip,
	389	unsigned gpio, int value)
	390	{
	391	struct ad7879 *ts = container_of(chip, struct ad7879, gc);
b4be468c	392
ec51b7f5 MH	393	mutex_lock(&ts->mutex);
	394	if (value)
	395	ts->cmd_crtl2 \|= AD7879_GPIO_DATA;
	396	else
	397	ts->cmd_crtl2 &= ~AD7879_GPIO_DATA;
b4be468c	398
4397c98a	399	ad7879_write(ts, AD7879_REG_CTRL2, ts->cmd_crtl2);
ec51b7f5 MH	400	mutex_unlock(&ts->mutex);
	401	}
	402
4397c98a MF	403	static int ad7879_gpio_add(struct ad7879 *ts,
4397c98a MF	404	const struct ad7879_platform_data *pdata)
ec51b7f5	405	{
ec51b7f5 MH	406	int ret = 0;
ec51b7f5 MH	407
14fbbc36 DT	408	mutex_init(&ts->mutex);
14fbbc36 DT	409
ec51b7f5 MH	410	if (pdata->gpio_export) {
	411	ts->gc.direction_input = ad7879_gpio_direction_input;
	412	ts->gc.direction_output = ad7879_gpio_direction_output;
	413	ts->gc.get = ad7879_gpio_get_value;
	414	ts->gc.set = ad7879_gpio_set_value;
	415	ts->gc.can_sleep = 1;
	416	ts->gc.base = pdata->gpio_base;
	417	ts->gc.ngpio = 1;
	418	ts->gc.label = "AD7879-GPIO";
	419	ts->gc.owner = THIS_MODULE;
4397c98a	420	ts->gc.dev = ts->dev;
ec51b7f5 MH	421
	422	ret = gpiochip_add(&ts->gc);
	423	if (ret)
4397c98a	424	dev_err(ts->dev, "failed to register gpio %d\n",
ec51b7f5 MH	425	ts->gc.base);
	426	}
	427
	428	return ret;
	429	}
	430
4397c98a	431	static void ad7879_gpio_remove(struct ad7879 *ts)
ec51b7f5	432	{
4397c98a	433	const struct ad7879_platform_data *pdata = ts->dev->platform_data;
ec51b7f5 MH	434	int ret;
	435
	436	if (pdata->gpio_export) {
	437	ret = gpiochip_remove(&ts->gc);
	438	if (ret)
4397c98a	439	dev_err(ts->dev, "failed to remove gpio %d\n",
ec51b7f5 MH	440	ts->gc.base);
	441	}
	442	}
	443	#else
4397c98a MF	444	static inline int ad7879_gpio_add(struct ad7879 *ts,
4397c98a MF	445	const struct ad7879_platform_data *pdata)
ec51b7f5 MH	446	{
	447	return 0;
	448	}
	449
4397c98a	450	static inline void ad7879_gpio_remove(struct ad7879 *ts)
ec51b7f5 MH	451	{
	452	}
	453	#endif
b4be468c	454
4397c98a MF	455	struct ad7879 ad7879_probe(struct device dev, u8 devid, unsigned int irq,
4397c98a MF	456	const struct ad7879_bus_ops *bops)
b4be468c	457	{
4397c98a MF	458	struct ad7879_platform_data *pdata = dev->platform_data;
4397c98a MF	459	struct ad7879 *ts;
b4be468c	460	struct input_dev *input_dev;
b4be468c MH	461	int err;
	462	u16 revid;
	463
4397c98a MF	464	if (!irq) {
	465	dev_err(dev, "no IRQ?\n");
	466	err = -EINVAL;
	467	goto err_out;
b4be468c MH	468	}
	469
	470	if (!pdata) {
4397c98a MF	471	dev_err(dev, "no platform data?\n");
	472	err = -EINVAL;
	473	goto err_out;
b4be468c MH	474	}
b4be468c MH	475
4397c98a	476	ts = kzalloc(sizeof(*ts), GFP_KERNEL);
b4be468c	477	input_dev = input_allocate_device();
4397c98a MF	478	if (!ts \|\| !input_dev) {
	479	err = -ENOMEM;
	480	goto err_free_mem;
	481	}
b4be468c	482
4397c98a MF	483	ts->bops = bops;
4397c98a MF	484	ts->dev = dev;
b4be468c	485	ts->input = input_dev;
14fbbc36	486	ts->irq = irq;
b4be468c MH	487
b4be468c MH	488	setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
4397c98a	489
b4be468c MH	490	ts->x_plate_ohms = pdata->x_plate_ohms ? : 400;
	491	ts->pressure_max = pdata->pressure_max ? : ~0;
	492
	493	ts->first_conversion_delay = pdata->first_conversion_delay;
	494	ts->acquisition_time = pdata->acquisition_time;
	495	ts->averaging = pdata->averaging;
	496	ts->pen_down_acc_interval = pdata->pen_down_acc_interval;
	497	ts->median = pdata->median;
	498
4397c98a	499	snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
b4be468c MH	500
	501	input_dev->name = "AD7879 Touchscreen";
	502	input_dev->phys = ts->phys;
4397c98a MF	503	input_dev->dev.parent = dev;
4397c98a MF	504	input_dev->id.bustype = bops->bustype;
b4be468c	505
14fbbc36 DT	506	input_dev->open = ad7879_open;
	507	input_dev->close = ad7879_close;
	508
	509	input_set_drvdata(input_dev, ts);
	510
b4be468c MH	511	__set_bit(EV_ABS, input_dev->evbit);
	512	__set_bit(ABS_X, input_dev->absbit);
	513	__set_bit(ABS_Y, input_dev->absbit);
	514	__set_bit(ABS_PRESSURE, input_dev->absbit);
	515
963ce8ae MH	516	__set_bit(EV_KEY, input_dev->evbit);
	517	__set_bit(BTN_TOUCH, input_dev->keybit);
	518
b4be468c MH	519	input_set_abs_params(input_dev, ABS_X,
	520	pdata->x_min ? : 0,
	521	pdata->x_max ? : MAX_12BIT,
	522	0, 0);
	523	input_set_abs_params(input_dev, ABS_Y,
	524	pdata->y_min ? : 0,
	525	pdata->y_max ? : MAX_12BIT,
	526	0, 0);
	527	input_set_abs_params(input_dev, ABS_PRESSURE,
	528	pdata->pressure_min, pdata->pressure_max, 0, 0);
	529
4397c98a	530	err = ad7879_write(ts, AD7879_REG_CTRL2, AD7879_RESET);
b4be468c	531	if (err < 0) {
4397c98a	532	dev_err(dev, "Failed to write %s\n", input_dev->name);
b4be468c MH	533	goto err_free_mem;
	534	}
	535
4397c98a MF	536	revid = ad7879_read(ts, AD7879_REG_REVID);
	537	input_dev->id.product = (revid & 0xff);
	538	input_dev->id.version = revid >> 8;
	539	if (input_dev->id.product != devid) {
	540	dev_err(dev, "Failed to probe %s (%x vs %x)\n",
	541	input_dev->name, devid, revid);
b4be468c MH	542	err = -ENODEV;
	543	goto err_free_mem;
	544	}
	545
ec51b7f5 MH	546	ts->cmd_crtl3 = AD7879_YPLUS_BIT \|
	547	AD7879_XPLUS_BIT \|
	548	AD7879_Z2_BIT \|
	549	AD7879_Z1_BIT \|
	550	AD7879_TEMPMASK_BIT \|
	551	AD7879_AUXVBATMASK_BIT \|
	552	AD7879_GPIOALERTMASK_BIT;
	553
	554	ts->cmd_crtl2 = AD7879_PM(AD7879_PM_DYN) \| AD7879_DFR \|
	555	AD7879_AVG(ts->averaging) \|
	556	AD7879_MFS(ts->median) \|
	557	AD7879_FCD(ts->first_conversion_delay);
	558
	559	ts->cmd_crtl1 = AD7879_MODE_INT \| AD7879_MODE_SEQ1 \|
	560	AD7879_ACQ(ts->acquisition_time) \|
	561	AD7879_TMR(ts->pen_down_acc_interval);
	562
4397c98a	563	err = request_threaded_irq(ts->irq, NULL, ad7879_irq,
7cd7a82d	564	IRQF_TRIGGER_FALLING,
4397c98a	565	dev_name(dev), ts);
b4be468c	566	if (err) {
4397c98a	567	dev_err(dev, "irq %d busy?\n", ts->irq);
b4be468c MH	568	goto err_free_mem;
	569	}
	570
14fbbc36 DT	571	__ad7879_disable(ts);
14fbbc36 DT	572
4397c98a	573	err = sysfs_create_group(&dev->kobj, &ad7879_attr_group);
b4be468c MH	574	if (err)
	575	goto err_free_irq;
	576
4397c98a	577	err = ad7879_gpio_add(ts, pdata);
b4be468c MH	578	if (err)
	579	goto err_remove_attr;
	580
ec51b7f5 MH	581	err = input_register_device(input_dev);
	582	if (err)
	583	goto err_remove_gpio;
	584
4397c98a	585	return ts;
b4be468c	586
ec51b7f5	587	err_remove_gpio:
4397c98a	588	ad7879_gpio_remove(ts);
b4be468c	589	err_remove_attr:
4397c98a	590	sysfs_remove_group(&dev->kobj, &ad7879_attr_group);
b4be468c	591	err_free_irq:
4397c98a	592	free_irq(ts->irq, ts);
b4be468c MH	593	err_free_mem:
b4be468c MH	594	input_free_device(input_dev);
4397c98a MF	595	kfree(ts);
	596	err_out:
	597	return ERR_PTR(err);
b4be468c	598	}
4397c98a	599	EXPORT_SYMBOL(ad7879_probe);
b4be468c	600
4397c98a	601	void ad7879_remove(struct ad7879 *ts)
b4be468c	602	{
4397c98a	603	ad7879_gpio_remove(ts);
4397c98a MF	604	sysfs_remove_group(&ts->dev->kobj, &ad7879_attr_group);
4397c98a MF	605	free_irq(ts->irq, ts);
b4be468c	606	input_unregister_device(ts->input);
b4be468c	607	kfree(ts);
b4be468c	608	}
4397c98a	609	EXPORT_SYMBOL(ad7879_remove);
b4be468c MH	610
	611	MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
	612	MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
	613	MODULE_LICENSE("GPL");