- 根目录:
- drivers
- input
- touchscreen
- tsc2005.c
/*
* TSC2005 touchscreen driver
*
* Copyright (C) 2006-2010 Nokia Corporation
*
* Author: Lauri Leukkunen <lauri.leukkunen@nokia.com>
* based on TSC2301 driver by Klaus K. Pedersen <klaus.k.pedersen@nokia.com>
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/pm.h>
#include <linux/spi/spi.h>
#include <linux/spi/tsc2005.h>
/*
* The touchscreen interface operates as follows:
*
* 1) Pen is pressed against the touchscreen.
* 2) TSC2005 performs AD conversion.
* 3) After the conversion is done TSC2005 drives DAV line down.
* 4) GPIO IRQ is received and tsc2005_irq_thread() is scheduled.
* 5) tsc2005_irq_thread() queues up an spi transfer to fetch the x, y, z1, z2
* values.
* 6) tsc2005_irq_thread() reports coordinates to input layer and sets up
* tsc2005_penup_timer() to be called after TSC2005_PENUP_TIME_MS (40ms).
* 7) When the penup timer expires, there have not been touch or DAV interrupts
* during the last 40ms which means the pen has been lifted.
*
* ESD recovery via a hardware reset is done if the TSC2005 doesn't respond
* after a configurable period (in ms) of activity. If esd_timeout is 0, the
* watchdog is disabled.
*/
/* control byte 1 */
#define TSC2005_CMD 0x80
#define TSC2005_CMD_NORMAL 0x00
#define TSC2005_CMD_STOP 0x01
#define TSC2005_CMD_12BIT 0x04
/* control byte 0 */
#define TSC2005_REG_READ 0x0001
#define TSC2005_REG_PND0 0x0002
#define TSC2005_REG_X 0x0000
#define TSC2005_REG_Y 0x0008
#define TSC2005_REG_Z1 0x0010
#define TSC2005_REG_Z2 0x0018
#define TSC2005_REG_TEMP_HIGH 0x0050
#define TSC2005_REG_CFR0 0x0060
#define TSC2005_REG_CFR1 0x0068
#define TSC2005_REG_CFR2 0x0070
/* configuration register 0 */
#define TSC2005_CFR0_PRECHARGE_276US 0x0040
#define TSC2005_CFR0_STABTIME_1MS 0x0300
#define TSC2005_CFR0_CLOCK_1MHZ 0x1000
#define TSC2005_CFR0_RESOLUTION12 0x2000
#define TSC2005_CFR0_PENMODE 0x8000
#define TSC2005_CFR0_INITVALUE (TSC2005_CFR0_STABTIME_1MS | \
TSC2005_CFR0_CLOCK_1MHZ | \
TSC2005_CFR0_RESOLUTION12 | \
TSC2005_CFR0_PRECHARGE_276US | \
TSC2005_CFR0_PENMODE)
/* bits common to both read and write of configuration register 0 */
#define TSC2005_CFR0_RW_MASK 0x3fff
/* configuration register 1 */
#define TSC2005_CFR1_BATCHDELAY_4MS 0x0003
#define TSC2005_CFR1_INITVALUE TSC2005_CFR1_BATCHDELAY_4MS
/* configuration register 2 */
#define TSC2005_CFR2_MAVE_Z 0x0004
#define TSC2005_CFR2_MAVE_Y 0x0008
#define TSC2005_CFR2_MAVE_X 0x0010
#define TSC2005_CFR2_AVG_7 0x0800
#define TSC2005_CFR2_MEDIUM_15 0x3000
#define TSC2005_CFR2_INITVALUE (TSC2005_CFR2_MAVE_X | \
TSC2005_CFR2_MAVE_Y | \
TSC2005_CFR2_MAVE_Z | \
TSC2005_CFR2_MEDIUM_15 | \
TSC2005_CFR2_AVG_7)
#define MAX_12BIT 0xfff
#define TSC2005_SPI_MAX_SPEED_HZ 10000000
#define TSC2005_PENUP_TIME_MS 40
struct tsc2005_spi_rd {
struct spi_transfer spi_xfer;
u32 spi_tx;
u32 spi_rx;
};
struct tsc2005 {
struct spi_device *spi;
struct spi_message spi_read_msg;
struct tsc2005_spi_rd spi_x;
struct tsc2005_spi_rd spi_y;
struct tsc2005_spi_rd spi_z1;
struct tsc2005_spi_rd spi_z2;
struct input_dev *idev;
char phys[32];
struct mutex mutex;
/* raw copy of previous x,y,z */
int in_x;
int in_y;
int in_z1;
int in_z2;
spinlock_t lock;
struct timer_list penup_timer;
unsigned int esd_timeout;
struct delayed_work esd_work;
unsigned long last_valid_interrupt;
unsigned int x_plate_ohm;
bool opened;
bool suspended;
bool pen_down;
void (*set_reset)(bool enable);
};
static int tsc2005_cmd(struct tsc2005 *ts, u8 cmd)
{
u8 tx = TSC2005_CMD | TSC2005_CMD_12BIT | cmd;
struct spi_transfer xfer = {
.tx_buf = &tx,
.len = 1,
.bits_per_word = 8,
};
struct spi_message msg;
int error;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error) {
dev_err(&ts->spi->dev, "%s: failed, command: %x, error: %d\n",
__func__, cmd, error);
return error;
}
return 0;
}
static int tsc2005_write(struct tsc2005 *ts, u8 reg, u16 value)
{
u32 tx = ((reg | TSC2005_REG_PND0) << 16) | value;
struct spi_transfer xfer = {
.tx_buf = &tx,
.len = 4,
.bits_per_word = 24,
};
struct spi_message msg;
int error;
spi_message_init(&msg);
spi_message_add_tail(&xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error) {
dev_err(&ts->spi->dev,
"%s: failed, register: %x, value: %x, error: %d\n",
__func__, reg, value, error);
return error;
}
return 0;
}
static void tsc2005_setup_read(struct tsc2005_spi_rd *rd, u8 reg, bool last)
{
memset(rd, 0, sizeof(*rd));
rd->spi_tx = (reg | TSC2005_REG_READ) << 16;
rd->spi_xfer.tx_buf = &rd->spi_tx;
rd->spi_xfer.rx_buf = &rd->spi_rx;
rd->spi_xfer.len = 4;
rd->spi_xfer.bits_per_word = 24;
rd->spi_xfer.cs_change = !last;
}
static int tsc2005_read(struct tsc2005 *ts, u8 reg, u16 *value)
{
struct tsc2005_spi_rd spi_rd;
struct spi_message msg;
int error;
tsc2005_setup_read(&spi_rd, reg, true);
spi_message_init(&msg);
spi_message_add_tail(&spi_rd.spi_xfer, &msg);
error = spi_sync(ts->spi, &msg);
if (error)
return error;
*value = spi_rd.spi_rx;
return 0;
}
static void tsc2005_update_pen_state(struct tsc2005 *ts,
int x, int y, int pressure)
{
if (pressure) {
input_report_abs(ts->idev, ABS_X, x);
input_report_abs(ts->idev, ABS_Y, y);
input_report_abs(ts->idev, ABS_PRESSURE, pressure);
if (!ts->pen_down) {
input_report_key(ts->idev, BTN_TOUCH, !!pressure);
ts->pen_down = true;
}
} else {
input_report_abs(ts->idev, ABS_PRESSURE, 0);
if (ts->pen_down) {
input_report_key(ts->idev, BTN_TOUCH, 0);
ts->pen_down = false;
}
}
input_sync(ts->idev);
dev_dbg(&ts->spi->dev, "point(%4d,%4d), pressure (%4d)\n", x, y,
pressure);
}
static irqreturn_t tsc2005_irq_thread(int irq, void *_ts)
{
struct tsc2005 *ts = _ts;
unsigned long flags;
unsigned int pressure;
u32 x, y;
u32 z1, z2;
int error;
/* read the coordinates */
error = spi_sync(ts->spi, &ts->spi_read_msg);
if (unlikely(error))
goto out;
x = ts->spi_x.spi_rx;
y = ts->spi_y.spi_rx;
z1 = ts->spi_z1.spi_rx;
z2 = ts->spi_z2.spi_rx;
/* validate position */
if (unlikely(x > MAX_12BIT || y > MAX_12BIT))
goto out;
/* Skip reading if the pressure components are out of range */
if (unlikely(z1 == 0 || z2 > MAX_12BIT || z1 >= z2))
goto out;
/*
* Skip point if this is a pen down with the exact same values as
* the value before pen-up - that implies SPI fed us stale data
*/
if (!ts->pen_down &&
ts->in_x == x && ts->in_y == y &&
ts->in_z1 == z1 && ts->in_z2 == z2) {
goto out;
}
/*
* At this point we are happy we have a valid and useful reading.
* Remember it for later comparisons. We may now begin downsampling.
*/
ts->in_x = x;
ts->in_y = y;
ts->in_z1 = z1;
ts->in_z2 = z2;
/* Compute touch pressure resistance using equation #1 */
pressure = x * (z2 - z1) / z1;
pressure = pressure * ts->x_plate_ohm / 4096;
if (unlikely(pressure > MAX_12BIT))
goto out;
spin_lock_irqsave(&ts->lock, flags);
tsc2005_update_pen_state(ts, x, y, pressure);
mod_timer(&ts->penup_timer,
jiffies + msecs_to_jiffies(TSC2005_PENUP_TIME_MS));
spin_unlock_irqrestore(&ts->lock, flags);
ts->last_valid_interrupt = jiffies;
out:
return IRQ_HANDLED;
}
static void tsc2005_penup_timer(unsigned long data)
{
struct tsc2005 *ts = (struct tsc2005 *)data;
unsigned long flags;
spin_lock_irqsave(&ts->lock, flags);
tsc2005_update_pen_state(ts, 0, 0, 0);
spin_unlock_irqrestore(&ts->lock, flags);
}
static void tsc2005_start_scan(struct tsc2005 *ts)
{
tsc2005_write(ts, TSC2005_REG_CFR0, TSC2005_CFR0_INITVALUE);
tsc2005_write(ts, TSC2005_REG_CFR1, TSC2005_CFR1_INITVALUE);
tsc2005_write(ts, TSC2005_REG_CFR2, TSC2005_CFR2_INITVALUE);
tsc2005_cmd(ts, TSC2005_CMD_NORMAL);
}
static void tsc2005_stop_scan(struct tsc2005 *ts)
{
tsc2005_cmd(ts, TSC2005_CMD_STOP);
}
/* must be called with ts->mutex held */
static void __tsc2005_disable(struct tsc2005 *ts)
{
tsc2005_stop_scan(ts);
disable_irq(ts->spi->irq);
del_timer_sync(&ts->penup_timer);
cancel_delayed_work_sync(&ts->esd_work);
enable_irq(ts->spi->irq);
}
/* must be called with ts->mutex held */
static void __tsc2005_enable(struct tsc2005 *ts)
{
tsc2005_start_scan(ts);
if (ts->esd_timeout && ts->set_reset) {
ts->last_valid_interrupt = jiffies;
schedule_delayed_work(&ts->esd_work,
round_jiffies_relative(
msecs_to_jiffies(ts->esd_timeout)));
}
}
static ssize_t tsc2005_selftest_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct spi_device *spi = to_spi_device(dev);
struct tsc2005 *ts = spi_get_drvdata(spi);
u16 temp_high;
u16 temp_high_orig;
u16 temp_high_test;
bool success = true;
int error;
mutex_lock(&ts->mutex);
/*
* Test TSC2005 communications via temp high register.
*/
__tsc2005_disable(ts);
error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high_orig);
if (error) {
dev_warn(dev, "selftest failed: read error %d\n", error);
success = false;
goto out;
}
temp_high_test = (temp_high_orig - 1) & MAX_12BIT;
error = tsc2005_write(ts, TSC2005_REG_TEMP_HIGH, temp_high_test);
if (error) {
dev_warn(dev, "selftest failed: write error %d\n", error);
success = false;
goto out;
}
error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
if (error) {
dev_warn(dev, "selftest failed: read error %d after write\n",
error);
success = false;
goto out;
}
if (temp_high != temp_high_test) {
dev_warn(dev, "selftest failed: %d != %d\n",
temp_high, temp_high_test);
success = false;
}
/* hardware reset */
ts->set_reset(false);
usleep_range(100, 500); /* only 10us required */
ts->set_reset(true);
if (!success)
goto out;
/* test that the reset really happened */
error = tsc2005_read(ts, TSC2005_REG_TEMP_HIGH, &temp_high);
if (error) {
dev_warn(dev, "selftest failed: read error %d after reset\n",
error);
success = false;
goto out;
}
if (temp_high != temp_high_orig) {
dev_warn(dev, "selftest failed after reset: %d != %d\n",
temp_high, temp_high_orig);
success = false;
}
out:
__tsc2005_enable(ts);
mutex_unlock(&ts->mutex);
return sprintf(buf, "%d\n", success);
}
static DEVICE_ATTR(selftest, S_IRUGO, tsc2005_selftest_show, NULL);
static struct attribute *tsc2005_attrs[] = {
&dev_attr_selftest.attr,
NULL
};
static mode_t tsc2005_attr_is_visible(struct kobject *kobj,
struct attribute *attr, int n)
{
struct device *dev = container_of(kobj, struct device, kobj);
struct spi_device *spi = to_spi_device(dev);
struct tsc2005 *ts = spi_get_drvdata(spi);
mode_t mode = attr->mode;
if (attr == &dev_attr_selftest.attr) {
if (!ts->set_reset)
mode = 0;
}
return mode;
}
static const struct attribute_group tsc2005_attr_group = {
.is_visible = tsc2005_attr_is_visible,
.attrs = tsc2005_attrs,
};
static void tsc2005_esd_work(struct work_struct *work)
{
struct tsc2005 *ts = container_of(work, struct tsc2005, esd_work.work);
int error;
u16 r;
if (!mutex_trylock(&ts->mutex)) {
/*
* If the mutex is taken, it means that disable or enable is in
* progress. In that case just reschedule the work. If the work
* is not needed, it will be canceled by disable.
*/
goto reschedule;
}
if (time_is_after_jiffies(ts->last_valid_interrupt +
msecs_to_jiffies(ts->esd_timeout)))
goto out;
/* We should be able to read register without disabling interrupts. */
error = tsc2005_read(ts, TSC2005_REG_CFR0, &r);
if (!error &&
!((r ^ TSC2005_CFR0_INITVALUE) & TSC2005_CFR0_RW_MASK)) {
goto out;
}
/*
* If we could not read our known value from configuration register 0
* then we should reset the controller as if from power-up and start
* scanning again.
*/
dev_info(&ts->spi->dev, "TSC2005 not responding - resetting\n");
disable_irq(ts->spi->irq);
del_timer_sync(&ts->penup_timer);
tsc2005_update_pen_state(ts, 0, 0, 0);
ts->set_reset(false);
usleep_range(100, 500); /* only 10us required */
ts->set_reset(true);
enable_irq(ts->spi->irq);
tsc2005_start_scan(ts);
out:
mutex_unlock(&ts->mutex);
reschedule:
/* re-arm the watchdog */
schedule_delayed_work(&ts->esd_work,
round_jiffies_relative(
msecs_to_jiffies(ts->esd_timeout)));
}
static int tsc2005_open(struct input_dev *input)
{
struct tsc2005 *ts = input_get_drvdata(input);
mutex_lock(&ts->mutex);
if (!ts->suspended)
__tsc2005_enable(ts);
ts->opened = true;
mutex_unlock(&ts->mutex);
return 0;
}
static void tsc2005_close(struct input_dev *input)
{
struct tsc2005 *ts = input_get_drvdata(input);
mutex_lock(&ts->mutex);
if (!ts->suspended)
__tsc2005_disable(ts);
ts->opened = false;
mutex_unlock(&ts->mutex);
}
static void __devinit tsc2005_setup_spi_xfer(struct tsc2005 *ts)
{
tsc2005_setup_read(&ts->spi_x, TSC2005_REG_X, false);
tsc2005_setup_read(&ts->spi_y, TSC2005_REG_Y, false);
tsc2005_setup_read(&ts->spi_z1, TSC2005_REG_Z1, false);
tsc2005_setup_read(&ts->spi_z2, TSC2005_REG_Z2, true);
spi_message_init(&ts->spi_read_msg);
spi_message_add_tail(&ts->spi_x.spi_xfer, &ts->spi_read_msg);
spi_message_add_tail(&ts->spi_y.spi_xfer, &ts->spi_read_msg);
spi_message_add_tail(&ts->spi_z1.spi_xfer, &ts->spi_read_msg);
spi_message_add_tail(&ts->spi_z2.spi_xfer, &ts->spi_read_msg);
}
static int __devinit tsc2005_probe(struct spi_device *spi)
{
const struct tsc2005_platform_data *pdata = spi->dev.platform_data;
struct tsc2005 *ts;
struct input_dev *input_dev;
unsigned int max_x, max_y, max_p;
unsigned int fudge_x, fudge_y, fudge_p;
int error;
if (!pdata) {
dev_dbg(&spi->dev, "no platform data\n");
return -ENODEV;
}
fudge_x = pdata->ts_x_fudge ? : 4;
fudge_y = pdata->ts_y_fudge ? : 8;
fudge_p = pdata->ts_pressure_fudge ? : 2;
max_x = pdata->ts_x_max ? : MAX_12BIT;
max_y = pdata->ts_y_max ? : MAX_12BIT;
max_p = pdata->ts_pressure_max ? : MAX_12BIT;
if (spi->irq <= 0) {
dev_dbg(&spi->dev, "no irq\n");
return -ENODEV;
}
spi->mode = SPI_MODE_0;
spi->bits_per_word = 8;
if (!spi->max_speed_hz)
spi->max_speed_hz = TSC2005_SPI_MAX_SPEED_HZ;
error = spi_setup(spi);
if (error)
return error;
ts = kzalloc(sizeof(*ts), GFP_KERNEL);
input_dev = input_allocate_device();
if (!ts || !input_dev) {
error = -ENOMEM;
goto err_free_mem;
}
ts->spi = spi;
ts->idev = input_dev;
ts->x_plate_ohm = pdata->ts_x_plate_ohm ? : 280;
ts->esd_timeout = pdata->esd_timeout_ms;
ts->set_reset = pdata->set_reset;
mutex_init(&ts->mutex);
spin_lock_init(&ts->lock);
setup_timer(&ts->penup_timer, tsc2005_penup_timer, (unsigned long)ts);
INIT_DELAYED_WORK(&ts->esd_work, tsc2005_esd_work);
tsc2005_setup_spi_xfer(ts);
snprintf(ts->phys, sizeof(ts->phys),
"%s/input-ts", dev_name(&spi->dev));
input_dev->name = "TSC2005 touchscreen";
input_dev->phys = ts->phys;
input_dev->id.bustype = BUS_SPI;
input_dev->dev.parent = &spi->dev;
input_dev->evbit[0] = BIT(EV_ABS) | BIT(EV_KEY);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(input_dev, ABS_X, 0, max_x, fudge_x, 0);
input_set_abs_params(input_dev, ABS_Y, 0, max_y, fudge_y, 0);
input_set_abs_params(input_dev, ABS_PRESSURE, 0, max_p, fudge_p, 0);
input_dev->open = tsc2005_open;
input_dev->close = tsc2005_close;
input_set_drvdata(input_dev, ts);
/* Ensure the touchscreen is off */
tsc2005_stop_scan(ts);
error = request_threaded_irq(spi->irq, NULL, tsc2005_irq_thread,
IRQF_TRIGGER_RISING, "tsc2005", ts);
if (error) {
dev_err(&spi->dev, "Failed to request irq, err: %d\n", error);
goto err_free_mem;
}
spi_set_drvdata(spi, ts);
error = sysfs_create_group(&spi->dev.kobj, &tsc2005_attr_group);
if (error) {
dev_err(&spi->dev,
"Failed to create sysfs attributes, err: %d\n", error);
goto err_clear_drvdata;
}
error = input_register_device(ts->idev);
if (error) {
dev_err(&spi->dev,
"Failed to register input device, err: %d\n", error);
goto err_remove_sysfs;
}
irq_set_irq_wake(spi->irq, 1);
return 0;
err_remove_sysfs:
sysfs_remove_group(&spi->dev.kobj, &tsc2005_attr_group);
err_clear_drvdata:
spi_set_drvdata(spi, NULL);
free_irq(spi->irq, ts);
err_free_mem:
input_free_device(input_dev);
kfree(ts);
return error;
}
static int __devexit tsc2005_remove(struct spi_device *spi)
{
struct tsc2005 *ts = spi_get_drvdata(spi);
sysfs_remove_group(&ts->spi->dev.kobj, &tsc2005_attr_group);
free_irq(ts->spi->irq, ts);
input_unregister_device(ts->idev);
kfree(ts);
spi_set_drvdata(spi, NULL);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int tsc2005_suspend(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct tsc2005 *ts = spi_get_drvdata(spi);
mutex_lock(&ts->mutex);
if (!ts->suspended && ts->opened)
__tsc2005_disable(ts);
ts->suspended = true;
mutex_unlock(&ts->mutex);
return 0;
}
static int tsc2005_resume(struct device *dev)
{
struct spi_device *spi = to_spi_device(dev);
struct tsc2005 *ts = spi_get_drvdata(spi);
mutex_lock(&ts->mutex);
if (ts->suspended && ts->opened)
__tsc2005_enable(ts);
ts->suspended = false;
mutex_unlock(&ts->mutex);
return 0;
}
#endif
static SIMPLE_DEV_PM_OPS(tsc2005_pm_ops, tsc2005_suspend, tsc2005_resume);
static struct spi_driver tsc2005_driver = {
.driver = {
.name = "tsc2005",
.owner = THIS_MODULE,
.pm = &tsc2005_pm_ops,
},
.probe = tsc2005_probe,
.remove = __devexit_p(tsc2005_remove),
};
static int __init tsc2005_init(void)
{
return spi_register_driver(&tsc2005_driver);
}
module_init(tsc2005_init);
static void __exit tsc2005_exit(void)
{
spi_unregister_driver(&tsc2005_driver);
}
module_exit(tsc2005_exit);
MODULE_AUTHOR("Lauri Leukkunen <lauri.leukkunen@nokia.com>");
MODULE_DESCRIPTION("TSC2005 Touchscreen Driver");
MODULE_LICENSE("GPL");