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Input: add AD7879 Touchscreen driver

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[randy.dunlap@oracle.com: don't use bus_id]
[dtor@mail.ru: locking and other fixups]
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Michael Hennerich 2009-03-09 20:12:52 -07:00 committed by Dmitry Torokhov
parent 331b78ed30
commit b4be468cc1
4 changed files with 850 additions and 0 deletions
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32
drivers/input/touchscreen/Kconfig
View file

@ -42,6 +42,38 @@ config TOUCHSCREEN_AD7877
To compile this driver as a module, choose M here: the
module will be called ad7877.
config TOUCHSCREEN_AD7879_I2C
tristate "AD7879 based touchscreens: AD7879-1 I2C Interface"
depends on I2C
select TOUCHSCREEN_AD7879
help
Say Y here if you have a touchscreen interface using the
AD7879-1 controller, and your board-specific initialization
code includes that in its table of I2C devices.
If unsure, say N (but it's safe to say "Y").
To compile this driver as a module, choose M here: the
module will be called ad7879.
config TOUCHSCREEN_AD7879_SPI
tristate "AD7879 based touchscreens: AD7879 SPI Interface"
depends on SPI_MASTER && TOUCHSCREEN_AD7879_I2C = n
select TOUCHSCREEN_AD7879
help
Say Y here if you have a touchscreen interface using the
AD7879 controller, and your board-specific initialization
code includes that in its table of SPI devices.
If unsure, say N (but it's safe to say "Y").
To compile this driver as a module, choose M here: the
module will be called ad7879.
config TOUCHSCREEN_AD7879
tristate
default n
config TOUCHSCREEN_BITSY
tristate "Compaq iPAQ H3600 (Bitsy) touchscreen"
depends on SA1100_BITSY

1
drivers/input/touchscreen/Makefile
View file

@ -7,6 +7,7 @@
wm97xx-ts-y := wm97xx-core.o
obj-$(CONFIG_TOUCHSCREEN_AD7877) += ad7877.o
obj-$(CONFIG_TOUCHSCREEN_AD7879) += ad7879.o
obj-$(CONFIG_TOUCHSCREEN_ADS7846) += ads7846.o
obj-$(CONFIG_TOUCHSCREEN_ATMEL_TSADCC) += atmel_tsadcc.o
obj-$(CONFIG_TOUCHSCREEN_BITSY) += h3600_ts_input.o

782
drivers/input/touchscreen/ad7879.c Normal file
View file

@ -0,0 +1,782 @@
/*
* Copyright (C) 2008 Michael Hennerich, Analog Devices Inc.
*
* Description: AD7879 based touchscreen, and GPIO driver (I2C/SPI Interface)
*
* Bugs: Enter bugs at http://blackfin.uclinux.org/
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see the file COPYING, or write
* to the Free Software Foundation, Inc.,
* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* 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/workqueue.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/spi/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)
#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
#define AD7879_DEVID 0x7A
typedef struct spi_device bus_device;
#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
#define AD7879_DEVID 0x79
typedef struct i2c_client bus_device;
#endif
struct ad7879 {
bus_device *bus;
struct input_dev *input;
struct work_struct work;
struct timer_list timer;
struct mutex mutex;
unsigned disabled:1; /* P: mutex */
#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
struct spi_message msg;
struct spi_transfer xfer[AD7879_NR_SENSE + 1];
u16 cmd;
#endif
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 gpio_init;
u16 cmd_crtl1;
u16 cmd_crtl2;
u16 cmd_crtl3;
unsigned gpio:1;
};
static int ad7879_read(bus_device *, u8);
static int ad7879_write(bus_device *, u8, u16);
static void ad7879_collect(struct ad7879 *);
static void 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;
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);
}
}
static void ad7879_work(struct work_struct *work)
{
struct ad7879 *ts = container_of(work, struct ad7879, work);
/* use keventd context to read the result registers */
ad7879_collect(ts);
ad7879_report(ts);
mod_timer(&ts->timer, jiffies + TS_PEN_UP_TIMEOUT);
}
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_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;
/* The repeated conversion sequencer controlled by TMR kicked off too fast.
* We ignore the last and process the sample sequence currently in the queue.
* It can't be older than 9.4ms
*/
if (!work_pending(&ts->work))
schedule_work(&ts->work);
return IRQ_HANDLED;
}
static void ad7879_setup(struct ad7879 *ts)
{
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->gpio_init;
ts->cmd_crtl1 = AD7879_MODE_INT | AD7879_MODE_SEQ1 |
AD7879_ACQ(ts->acquisition_time) |
AD7879_TMR(ts->pen_down_acc_interval);
ad7879_write(ts->bus, AD7879_REG_CTRL2, ts->cmd_crtl2);
ad7879_write(ts->bus, AD7879_REG_CTRL3, ts->cmd_crtl3);
ad7879_write(ts->bus, AD7879_REG_CTRL1, ts->cmd_crtl1);
}
static void ad7879_disable(struct ad7879 *ts)
{
mutex_lock(&ts->mutex);
if (!ts->disabled) {
ts->disabled = 1;
disable_irq(ts->bus->irq);
cancel_work_sync(&ts->work);
if (del_timer_sync(&ts->timer))
ad7879_ts_event_release(ts);
ad7879_write(ts->bus, AD7879_REG_CTRL2,
AD7879_PM(AD7879_PM_SHUTDOWN));
}
mutex_unlock(&ts->mutex);
}
static void ad7879_enable(struct ad7879 *ts)
{
mutex_lock(&ts->mutex);
if (ts->disabled) {
ad7879_setup(ts);
ts->disabled = 0;
enable_irq(ts->bus->irq);
}
mutex_unlock(&ts->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;
if (val)
ad7879_disable(ts);
else
ad7879_enable(ts);
return count;
}
static DEVICE_ATTR(disable, 0664, ad7879_disable_show, ad7879_disable_store);
static ssize_t ad7879_gpio_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ad7879 *ts = dev_get_drvdata(dev);
return sprintf(buf, "%u\n", ts->gpio);
}
static ssize_t ad7879_gpio_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;
mutex_lock(&ts->mutex);
ts->gpio = !!val;
error = ad7879_write(ts->bus, AD7879_REG_CTRL2,
ts->gpio ?
ts->cmd_crtl2 & ~AD7879_GPIO_DATA :
ts->cmd_crtl2 | AD7879_GPIO_DATA);
mutex_unlock(&ts->mutex);
return error ? : count;
}
static DEVICE_ATTR(gpio, 0664, ad7879_gpio_show, ad7879_gpio_store);
static struct attribute *ad7879_attributes[] = {
&dev_attr_disable.attr,
&dev_attr_gpio.attr,
NULL
};
static const struct attribute_group ad7879_attr_group = {
.attrs = ad7879_attributes,
};
static int __devinit ad7879_construct(bus_device *bus, struct ad7879 *ts)
{
struct input_dev *input_dev;
struct ad7879_platform_data *pdata = bus->dev.platform_data;
int err;
u16 revid;
if (!bus->irq) {
dev_err(&bus->dev, "no IRQ?\n");
return -ENODEV;
}
if (!pdata) {
dev_err(&bus->dev, "no platform data?\n");
return -ENODEV;
}
input_dev = input_allocate_device();
if (!input_dev)
return -ENOMEM;
ts->input = input_dev;
setup_timer(&ts->timer, ad7879_timer, (unsigned long) ts);
INIT_WORK(&ts->work, ad7879_work);
mutex_init(&ts->mutex);
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;
if (pdata->gpio_output)
ts->gpio_init = AD7879_GPIO_EN |
(pdata->gpio_default ? 0 : AD7879_GPIO_DATA);
else
ts->gpio_init = AD7879_GPIO_EN | AD7879_GPIODIR;
snprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(&bus->dev));
input_dev->name = "AD7879 Touchscreen";
input_dev->phys = ts->phys;
input_dev->dev.parent = &bus->dev;
__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);
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(bus, AD7879_REG_CTRL2, AD7879_RESET);
if (err < 0) {
dev_err(&bus->dev, "Failed to write %s\n", input_dev->name);
goto err_free_mem;
}
revid = ad7879_read(bus, AD7879_REG_REVID);
if ((revid & 0xFF) != AD7879_DEVID) {
dev_err(&bus->dev, "Failed to probe %s\n", input_dev->name);
err = -ENODEV;
goto err_free_mem;
}
ad7879_setup(ts);
err = request_irq(bus->irq, ad7879_irq,
IRQF_TRIGGER_FALLING | IRQF_SAMPLE_RANDOM,
bus->dev.driver->name, ts);
if (err) {
dev_err(&bus->dev, "irq %d busy?\n", bus->irq);
goto err_free_mem;
}
err = sysfs_create_group(&bus->dev.kobj, &ad7879_attr_group);
if (err)
goto err_free_irq;
err = input_register_device(input_dev);
if (err)
goto err_remove_attr;
dev_info(&bus->dev, "Rev.%d touchscreen, irq %d\n",
revid >> 8, bus->irq);
return 0;
err_remove_attr:
sysfs_remove_group(&bus->dev.kobj, &ad7879_attr_group);
err_free_irq:
free_irq(bus->irq, ts);
err_free_mem:
input_free_device(input_dev);
return err;
}
static int __devexit ad7879_destroy(bus_device *bus, struct ad7879 *ts)
{
ad7879_disable(ts);
sysfs_remove_group(&ts->bus->dev.kobj, &ad7879_attr_group);
free_irq(ts->bus->irq, ts);
input_unregister_device(ts->input);
dev_dbg(&bus->dev, "unregistered touchscreen\n");
return 0;
}
#ifdef CONFIG_PM
static int ad7879_suspend(bus_device *bus, pm_message_t message)
{
struct ad7879 *ts = dev_get_drvdata(&bus->dev);
ad7879_disable(ts);
return 0;
}
static int ad7879_resume(bus_device *bus)
{
struct ad7879 *ts = dev_get_drvdata(&bus->dev);
ad7879_enable(ts);
return 0;
}
#else
#define ad7879_suspend NULL
#define ad7879_resume NULL
#endif
#if defined(CONFIG_TOUCHSCREEN_AD7879_SPI) || defined(CONFIG_TOUCHSCREEN_AD7879_SPI_MODULE)
#define MAX_SPI_FREQ_HZ 5000000
#define AD7879_CMD_MAGIC 0xE000
#define AD7879_CMD_READ (1 << 10)
#define AD7879_WRITECMD(reg) (AD7879_CMD_MAGIC | (reg & 0xF))
#define AD7879_READCMD(reg) (AD7879_CMD_MAGIC | AD7879_CMD_READ | (reg & 0xF))
struct ser_req {
u16 command;
u16 data;
struct spi_message msg;
struct spi_transfer xfer[2];
};
/*
* ad7879_read/write are only used for initial setup and for sysfs controls.
* The main traffic is done in ad7879_collect().
*/
static int ad7879_read(struct spi_device *spi, u8 reg)
{
struct ser_req *req;
int status, ret;
req = kzalloc(sizeof *req, GFP_KERNEL);
if (!req)
return -ENOMEM;
spi_message_init(&req->msg);
req->command = (u16) AD7879_READCMD(reg);
req->xfer[0].tx_buf = &req->command;
req->xfer[0].len = 2;
req->xfer[1].rx_buf = &req->data;
req->xfer[1].len = 2;
spi_message_add_tail(&req->xfer[0], &req->msg);
spi_message_add_tail(&req->xfer[1], &req->msg);
status = spi_sync(spi, &req->msg);
ret = status ? : req->data;
kfree(req);
return ret;
}
static int ad7879_write(struct spi_device *spi, u8 reg, u16 val)
{
struct ser_req *req;
int status;
req = kzalloc(sizeof *req, GFP_KERNEL);
if (!req)
return -ENOMEM;
spi_message_init(&req->msg);
req->command = (u16) AD7879_WRITECMD(reg);
req->xfer[0].tx_buf = &req->command;
req->xfer[0].len = 2;
req->data = val;
req->xfer[1].tx_buf = &req->data;
req->xfer[1].len = 2;
spi_message_add_tail(&req->xfer[0], &req->msg);
spi_message_add_tail(&req->xfer[1], &req->msg);
status = spi_sync(spi, &req->msg);
kfree(req);
return status;
}
static void ad7879_collect(struct ad7879 *ts)
{
int status = spi_sync(ts->bus, &ts->msg);
if (status)
dev_err(&ts->bus->dev, "spi_sync --> %d\n", status);
}
static void ad7879_setup_ts_def_msg(struct ad7879 *ts)
{
struct spi_message *m;
int i;
ts->cmd = (u16) AD7879_READCMD(AD7879_REG_XPLUS);
m = &ts->msg;
spi_message_init(m);
ts->xfer[0].tx_buf = &ts->cmd;
ts->xfer[0].len = 2;
spi_message_add_tail(&ts->xfer[0], m);
for (i = 0; i < AD7879_NR_SENSE; i++) {
ts->xfer[i + 1].rx_buf = &ts->conversion_data[i];
ts->xfer[i + 1].len = 2;
spi_message_add_tail(&ts->xfer[i + 1], m);
}
}
static int __devinit ad7879_probe(struct spi_device *spi)
{
struct ad7879 *ts;
int error;
/* don't exceed max specified SPI CLK frequency */
if (spi->max_speed_hz > MAX_SPI_FREQ_HZ) {
dev_err(&spi->dev, "SPI CLK %d Hz?\n", spi->max_speed_hz);
return -EINVAL;
}
ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
if (!ts)
return -ENOMEM;
dev_set_drvdata(&spi->dev, ts);
ts->bus = spi;
ad7879_setup_ts_def_msg(ts);
error = ad7879_construct(spi, ts);
if (error) {
dev_set_drvdata(&spi->dev, NULL);
kfree(ts);
}
return 0;
}
static int __devexit ad7879_remove(struct spi_device *spi)
{
struct ad7879 *ts = dev_get_drvdata(&spi->dev);
ad7879_destroy(spi, ts);
dev_set_drvdata(&spi->dev, NULL);
kfree(ts);
return 0;
}
static struct spi_driver ad7879_driver = {
.driver = {
.name = "ad7879",
.bus = &spi_bus_type,
.owner = THIS_MODULE,
},
.probe = ad7879_probe,
.remove = __devexit_p(ad7879_remove),
.suspend = ad7879_suspend,
.resume = ad7879_resume,
};
static int __init ad7879_init(void)
{
return spi_register_driver(&ad7879_driver);
}
module_init(ad7879_init);
static void __exit ad7879_exit(void)
{
spi_unregister_driver(&ad7879_driver);
}
module_exit(ad7879_exit);
#elif defined(CONFIG_TOUCHSCREEN_AD7879_I2C) || defined(CONFIG_TOUCHSCREEN_AD7879_I2C_MODULE)
/* All registers are word-sized.
* AD7879 uses a high-byte first convention.
*/
static int ad7879_read(struct i2c_client *client, u8 reg)
{
return swab16(i2c_smbus_read_word_data(client, reg));
}
static int ad7879_write(struct i2c_client *client, u8 reg, u16 val)
{
return i2c_smbus_write_word_data(client, reg, swab16(val));
}
static void ad7879_collect(struct ad7879 *ts)
{
int i;
for (i = 0; i < AD7879_NR_SENSE; i++)
ts->conversion_data[i] = ad7879_read(ts->bus,
AD7879_REG_XPLUS + i);
}
static int __devinit ad7879_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct ad7879 *ts;
int error;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_WORD_DATA)) {
dev_err(&client->dev, "SMBUS Word Data not Supported\n");
return -EIO;
}
ts = kzalloc(sizeof(struct ad7879), GFP_KERNEL);
if (!ts)
return -ENOMEM;
i2c_set_clientdata(client, ts);
ts->bus = client;
error = ad7879_construct(client, ts);
if (error) {
i2c_set_clientdata(client, NULL);
kfree(ts);
}
return 0;
}
static int __devexit ad7879_remove(struct i2c_client *client)
{
struct ad7879 *ts = dev_get_drvdata(&client->dev);
ad7879_destroy(client, ts);
i2c_set_clientdata(client, NULL);
kfree(ts);
return 0;
}
static const struct i2c_device_id ad7879_id[] = {
{ "ad7879", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, ad7879_id);
static struct i2c_driver ad7879_driver = {
.driver = {
.name = "ad7879",
.owner = THIS_MODULE,
},
.probe = ad7879_probe,
.remove = __devexit_p(ad7879_remove),
.suspend = ad7879_suspend,
.resume = ad7879_resume,
.id_table = ad7879_id,
};
static int __init ad7879_init(void)
{
return i2c_add_driver(&ad7879_driver);
}
module_init(ad7879_init);
static void __exit ad7879_exit(void)
{
i2c_del_driver(&ad7879_driver);
}
module_exit(ad7879_exit);
#endif
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("AD7879(-1) touchscreen Driver");
MODULE_LICENSE("GPL");

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include/linux/spi/ad7879.h Normal file
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/* linux/spi/ad7879.h */
/* Touchscreen characteristics vary between boards and models. The
* platform_data for the device's "struct device" holds this information.
*
* It's OK if the min/max values are zero.
*/
struct ad7879_platform_data {
u16 model; /* 7879 */
u16 x_plate_ohms;
u16 x_min, x_max;
u16 y_min, y_max;
u16 pressure_min, pressure_max;
/* [0..255] 0=OFF Starts at 1=550us and goes
* all the way to 9.440ms in steps of 35us.
*/
u8 pen_down_acc_interval;
/* [0..15] Starts at 0=128us and goes all the
* way to 4.096ms in steps of 128us.
*/
u8 first_conversion_delay;
/* [0..3] 0 = 2us, 1 = 4us, 2 = 8us, 3 = 16us */
u8 acquisition_time;
/* [0..3] Average X middle samples 0 = 2, 1 = 4, 2 = 8, 3 = 16 */
u8 averaging;
/* [0..3] Perform X measurements 0 = OFF,
* 1 = 4, 2 = 8, 3 = 16 (median > averaging)
*/
u8 median;
/* 1 = AUX/VBAT/GPIO set to GPIO Output */
u8 gpio_output;
/* Initial GPIO pin state (valid if gpio_output = 1) */
u8 gpio_default;
};