- 根目录:
- 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 <linux/module.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 */
bool swap_xy;
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;
int x;
int y;
int Rt;
};
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;
if (ts->swap_xy)
swap(x, y);
/*
* 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;
/*
* Sample found inconsistent, pressure is beyond
* the maximum. Don't report it to user space.
*/
if (Rt > ts->pressure_max)
return -EINVAL;
/*
* Note that we delay reporting events by one sample.
* This is done to avoid reporting last sample of the
* touch sequence, which may be incomplete if finger
* leaves the surface before last reading is taken.
*/
if (timer_pending(&ts->timer)) {
/* Touch continues */
input_report_key(input_dev, BTN_TOUCH, 1);
input_report_abs(input_dev, ABS_X, ts->x);
input_report_abs(input_dev, ABS_Y, ts->y);
input_report_abs(input_dev, ABS_PRESSURE, ts->Rt);
input_sync(input_dev);
}
ts->x = x;
ts->y = y;
ts->Rt = Rt;
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)
{
u16 reg = (ts->cmd_crtl2 & ~AD7879_PM(-1)) |
AD7879_PM(AD7879_PM_SHUTDOWN);
disable_irq(ts->irq);
if (del_timer_sync(&ts->timer))
ad7879_ts_event_release(ts);
ad7879_write(ts, AD7879_REG_CTRL2, reg);
}
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);
}
#ifdef CONFIG_PM_SLEEP
static int ad7879_suspend(struct device *dev)
{
struct ad7879 *ts = dev_get_drvdata(dev);
mutex_lock(&ts->input->mutex);
if (!ts->suspended && !ts->disabled && ts->input->users)
__ad7879_disable(ts);
ts->suspended = true;
mutex_unlock(&ts->input->mutex);
return 0;
}
static int ad7879_resume(struct device *dev)
{
struct ad7879 *ts = dev_get_drvdata(dev);
mutex_lock(&ts->input->mutex);
if (ts->suspended && !ts->disabled && ts->input->users)
__ad7879_enable(ts);
ts->suspended = false;
mutex_unlock(&ts->input->mutex);
return 0;
}
#endif
SIMPLE_DEV_PM_OPS(ad7879_pm_ops, ad7879_suspend, ad7879_resume);
EXPORT_SYMBOL(ad7879_pm_ops);
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 int val;
int error;
error = kstrtouint(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;
ts->swap_xy = pdata->swap_xy;
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 | IRQF_ONESHOT,
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");