// SPDX-License-Identifier: GPL-2.0-only
/*
* Touchscreen driver for Dialog Semiconductor DA9034
*
* Copyright (C) 2006-2008 Marvell International Ltd.
* Fengwei Yin <[email protected]>
* Bin Yang <[email protected]>
* Eric Miao <[email protected]>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/workqueue.h>
#include <linux/mfd/da903x.h>
#include <linux/slab.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 da9034_touch_probe(struct platform_device *pdev)
{
struct da9034_touch_pdata *pdata = dev_get_platdata(&pdev->dev);
struct da9034_touch *touch;
struct input_dev *input_dev;
int error;
touch = devm_kzalloc(&pdev->dev, sizeof(struct da9034_touch),
GFP_KERNEL);
if (!touch) {
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 = devm_input_allocate_device(&pdev->dev);
if (!input_dev) {
dev_err(&pdev->dev, "failed to allocate input device\n");
return -ENOMEM;
}
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);
error = input_register_device(input_dev);
if (error)
return error;
return 0;
}
static struct platform_driver da9034_touch_driver = {
.driver = {
.name = "da9034-touch",
},
.probe = da9034_touch_probe,
};
module_platform_driver(da9034_touch_driver);
MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9034");
MODULE_AUTHOR("Eric Miao <[email protected]>, Bin Yang <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9034-touch");
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