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linux/drivers/input/touchscreen/da9034-ts.c
Eric Miao 7f6d5ff22b Input: da9034-ts - make pen {down,up} events more reliable 
PEN_{UP/DOWN} events are expected to be available soon after stopping
TSI auto measurement, but this is found not always be true. Work around
this by adding delay and simulating such an event (according to pen down
status bit).

Signed-off-by: Bin Yang <bin.yang@marvell.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
2009-04-15 08:58:22 -07:00

398 lines
8.8 KiB
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/*
* Touchscreen driver for Dialog Semiconductor DA9034
*
* Copyright (C) 2006-2008 Marvell International Ltd.
* Fengwei Yin <fengwei.yin@marvell.com>
* Bin Yang <bin.yang@marvell.com>
* Eric Miao <eric.miao@marvell.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/mfd/da903x.h>
#define DA9034_MANUAL_CTRL 0x50
#define DA9034_LDO_ADC_EN (1 << 4)
#define DA9034_AUTO_CTRL1 0x51
#define DA9034_AUTO_CTRL2 0x52
#define DA9034_AUTO_TSI_EN (1 << 3)
#define DA9034_PEN_DETECT (1 << 4)
#define DA9034_TSI_CTRL1 0x53
#define DA9034_TSI_CTRL2 0x54
#define DA9034_TSI_X_MSB 0x6c
#define DA9034_TSI_Y_MSB 0x6d
#define DA9034_TSI_XY_LSB 0x6e
enum {
STATE_IDLE, /* wait for pendown */
STATE_BUSY, /* TSI busy sampling */
STATE_STOP, /* sample available */
STATE_WAIT, /* Wait to start next sample */
};
enum {
EVENT_PEN_DOWN,
EVENT_PEN_UP,
EVENT_TSI_READY,
EVENT_TIMEDOUT,
};
struct da9034_touch {
struct device *da9034_dev;
struct input_dev *input_dev;
struct delayed_work tsi_work;
struct notifier_block notifier;
int state;
int interval_ms;
int x_inverted;
int y_inverted;
int last_x;
int last_y;
};
static inline int is_pen_down(struct da9034_touch *touch)
{
return da903x_query_status(touch->da9034_dev, DA9034_STATUS_PEN_DOWN);
}
static inline int detect_pen_down(struct da9034_touch *touch, int on)
{
if (on)
return da903x_set_bits(touch->da9034_dev,
DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
else
return da903x_clr_bits(touch->da9034_dev,
DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
}
static int read_tsi(struct da9034_touch *touch)
{
uint8_t _x, _y, _v;
int ret;
ret = da903x_read(touch->da9034_dev, DA9034_TSI_X_MSB, &_x);
if (ret)
return ret;
ret = da903x_read(touch->da9034_dev, DA9034_TSI_Y_MSB, &_y);
if (ret)
return ret;
ret = da903x_read(touch->da9034_dev, DA9034_TSI_XY_LSB, &_v);
if (ret)
return ret;
touch->last_x = ((_x << 2) & 0x3fc) | (_v & 0x3);
touch->last_y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
return 0;
}
static inline int start_tsi(struct da9034_touch *touch)
{
return da903x_set_bits(touch->da9034_dev,
DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
}
static inline int stop_tsi(struct da9034_touch *touch)
{
return da903x_clr_bits(touch->da9034_dev,
DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
}
static inline void report_pen_down(struct da9034_touch *touch)
{
int x = touch->last_x;
int y = touch->last_y;
x &= 0xfff;
if (touch->x_inverted)
x = 1024 - x;
y &= 0xfff;
if (touch->y_inverted)
y = 1024 - y;
input_report_abs(touch->input_dev, ABS_X, x);
input_report_abs(touch->input_dev, ABS_Y, y);
input_report_key(touch->input_dev, BTN_TOUCH, 1);
input_sync(touch->input_dev);
}
static inline void report_pen_up(struct da9034_touch *touch)
{
input_report_key(touch->input_dev, BTN_TOUCH, 0);
input_sync(touch->input_dev);
}
static void da9034_event_handler(struct da9034_touch *touch, int event)
{
int err;
switch (touch->state) {
case STATE_IDLE:
if (event != EVENT_PEN_DOWN)
break;
/* Enable auto measurement of the TSI, this will
* automatically disable pen down detection
*/
err = start_tsi(touch);
if (err)
goto err_reset;
touch->state = STATE_BUSY;
break;
case STATE_BUSY:
if (event != EVENT_TSI_READY)
break;
err = read_tsi(touch);
if (err)
goto err_reset;
/* Disable auto measurement of the TSI, so that
* pen down status will be available
*/
err = stop_tsi(touch);
if (err)
goto err_reset;
touch->state = STATE_STOP;
/* FIXME: PEN_{UP/DOWN} events are expected to be
* available by stopping TSI, but this is found not
* always true, delay and simulate such an event
* here is more reliable
*/
mdelay(1);
da9034_event_handler(touch,
is_pen_down(touch) ? EVENT_PEN_DOWN :
EVENT_PEN_UP);
break;
case STATE_STOP:
if (event == EVENT_PEN_DOWN) {
report_pen_down(touch);
schedule_delayed_work(&touch->tsi_work,
msecs_to_jiffies(touch->interval_ms));
touch->state = STATE_WAIT;
}
if (event == EVENT_PEN_UP) {
report_pen_up(touch);
touch->state = STATE_IDLE;
}
break;
case STATE_WAIT:
if (event != EVENT_TIMEDOUT)
break;
if (is_pen_down(touch)) {
start_tsi(touch);
touch->state = STATE_BUSY;
} else {
report_pen_up(touch);
touch->state = STATE_IDLE;
}
break;
}
return;
err_reset:
touch->state = STATE_IDLE;
stop_tsi(touch);
detect_pen_down(touch, 1);
}
static void da9034_tsi_work(struct work_struct *work)
{
struct da9034_touch *touch =
container_of(work, struct da9034_touch, tsi_work.work);
da9034_event_handler(touch, EVENT_TIMEDOUT);
}
static int da9034_touch_notifier(struct notifier_block *nb,
unsigned long event, void *data)
{
struct da9034_touch *touch =
container_of(nb, struct da9034_touch, notifier);
if (event & DA9034_EVENT_TSI_READY)
da9034_event_handler(touch, EVENT_TSI_READY);
if ((event & DA9034_EVENT_PEN_DOWN) && touch->state == STATE_IDLE)
da9034_event_handler(touch, EVENT_PEN_DOWN);
return 0;
}
static int da9034_touch_open(struct input_dev *dev)
{
struct da9034_touch *touch = input_get_drvdata(dev);
int ret;
ret = da903x_register_notifier(touch->da9034_dev, &touch->notifier,
DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
if (ret)
return -EBUSY;
/* Enable ADC LDO */
ret = da903x_set_bits(touch->da9034_dev,
DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
if (ret)
return ret;
/* TSI_DELAY: 3 slots, TSI_SKIP: 3 slots */
ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL1, 0x1b);
if (ret)
return ret;
ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL2, 0x00);
if (ret)
return ret;
touch->state = STATE_IDLE;
detect_pen_down(touch, 1);
return 0;
}
static void da9034_touch_close(struct input_dev *dev)
{
struct da9034_touch *touch = input_get_drvdata(dev);
da903x_unregister_notifier(touch->da9034_dev, &touch->notifier,
DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
cancel_delayed_work_sync(&touch->tsi_work);
touch->state = STATE_IDLE;
stop_tsi(touch);
detect_pen_down(touch, 0);
/* Disable ADC LDO */
da903x_clr_bits(touch->da9034_dev,
DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
}
static int __devinit da9034_touch_probe(struct platform_device *pdev)
{
struct da9034_touch_pdata *pdata = pdev->dev.platform_data;
struct da9034_touch *touch;
struct input_dev *input_dev;
int ret;
touch = kzalloc(sizeof(struct da9034_touch), GFP_KERNEL);
if (touch == NULL) {
dev_err(&pdev->dev, "failed to allocate driver data\n");
return -ENOMEM;
}
touch->da9034_dev = pdev->dev.parent;
if (pdata) {
touch->interval_ms = pdata->interval_ms;
touch->x_inverted = pdata->x_inverted;
touch->y_inverted = pdata->y_inverted;
} else
/* fallback into default */
touch->interval_ms = 10;
INIT_DELAYED_WORK(&touch->tsi_work, da9034_tsi_work);
touch->notifier.notifier_call = da9034_touch_notifier;
input_dev = input_allocate_device();
if (!input_dev) {
dev_err(&pdev->dev, "failed to allocate input device\n");
ret = -ENOMEM;
goto err_free_touch;
}
input_dev->name = pdev->name;
input_dev->open = da9034_touch_open;
input_dev->close = da9034_touch_close;
input_dev->dev.parent = &pdev->dev;
__set_bit(EV_ABS, input_dev->evbit);
__set_bit(ABS_X, input_dev->absbit);
__set_bit(ABS_Y, input_dev->absbit);
input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
__set_bit(EV_KEY, input_dev->evbit);
__set_bit(BTN_TOUCH, input_dev->keybit);
touch->input_dev = input_dev;
input_set_drvdata(input_dev, touch);
ret = input_register_device(input_dev);
if (ret)
goto err_free_input;
platform_set_drvdata(pdev, touch);
return 0;
err_free_input:
input_free_device(input_dev);
err_free_touch:
kfree(touch);
return ret;
}
static int __devexit da9034_touch_remove(struct platform_device *pdev)
{
struct da9034_touch *touch = platform_get_drvdata(pdev);
input_unregister_device(touch->input_dev);
kfree(touch);
return 0;
}
static struct platform_driver da9034_touch_driver = {
.driver = {
.name = "da9034-touch",
.owner = THIS_MODULE,
},
.probe = da9034_touch_probe,
.remove = __devexit_p(da9034_touch_remove),
};
static int __init da9034_touch_init(void)
{
return platform_driver_register(&da9034_touch_driver);
}
module_init(da9034_touch_init);
static void __exit da9034_touch_exit(void)
{
platform_driver_unregister(&da9034_touch_driver);
}
module_exit(da9034_touch_exit);
MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9034");
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>, Bin Yang <bin.yang@marvell.com>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9034-touch");
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