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Input: add support for touchscreen on W90P910 ARM platform
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The touchscreen works in two modes, wait trigger mode and auto-semi
mode. The device starts in wait trigger mode and waits until pressure
is detected, then device sets WT_INT bit and raises an interrupt.
The driver should put the device into auto-semi mode and prepare for
reading first X and then Y coordinates. When coordinate data is ready
the driver sets ADC_INT bit and raises interrupt again.

[dtor@mail.ru: various cleanups]
Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
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Wan ZongShun authored and Dmitry Torokhov committed Jun 11, 2009
1 parent 4894e4a commit 7e3f737
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8 changes: 8 additions & 0 deletions drivers/input/touchscreen/Kconfig
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Expand Up @@ -490,4 +490,12 @@ config TOUCHSCREEN_TSC2007
To compile this driver as a module, choose M here: the
module will be called tsc2007.

config TOUCHSCREEN_W90X900
tristate "W90P910 touchscreen driver"
help
Say Y here if you have a W90P910 based touchscreen.

To compile this driver as a module, choose M here: the
module will be called w90p910_ts.

endif
1 change: 1 addition & 0 deletions drivers/input/touchscreen/Makefile
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Expand Up @@ -39,3 +39,4 @@ wm97xx-ts-$(CONFIG_TOUCHSCREEN_WM9713) += wm9713.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_ATMEL) += atmel-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_MAINSTONE) += mainstone-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_WM97XX_ZYLONITE) += zylonite-wm97xx.o
obj-$(CONFIG_TOUCHSCREEN_W90X900) += w90p910_ts.o
350 changes: 350 additions & 0 deletions drivers/input/touchscreen/w90p910_ts.c
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@@ -0,0 +1,350 @@
/*
* Copyright (c) 2008 Nuvoton technology corporation.
*
* Wan ZongShun <mcuos.com@gmail.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;version 2 of the License.
*
*/

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/input.h>
#include <linux/interrupt.h>

/* ADC controller bit defines */
#define ADC_DELAY 0xf00
#define ADC_DOWN 0x01
#define ADC_TSC_Y (0x01 << 8)
#define ADC_TSC_X (0x00 << 8)
#define TSC_FOURWIRE (~(0x03 << 1))
#define ADC_CLK_EN (0x01 << 28) /* ADC clock enable */
#define ADC_READ_CON (0x01 << 12)
#define ADC_CONV (0x01 << 13)
#define ADC_SEMIAUTO (0x01 << 14)
#define ADC_WAITTRIG (0x03 << 14)
#define ADC_RST1 (0x01 << 16)
#define ADC_RST0 (0x00 << 16)
#define ADC_EN (0x01 << 17)
#define ADC_INT (0x01 << 18)
#define WT_INT (0x01 << 20)
#define ADC_INT_EN (0x01 << 21)
#define LVD_INT_EN (0x01 << 22)
#define WT_INT_EN (0x01 << 23)
#define ADC_DIV (0x04 << 1) /* div = 6 */

enum ts_state {
TS_WAIT_NEW_PACKET, /* We are waiting next touch report */
TS_WAIT_X_COORD, /* We are waiting for ADC to report X coord */
TS_WAIT_Y_COORD, /* We are waiting for ADC to report Y coord */
TS_IDLE, /* Input device is closed, don't do anything */
};

struct w90p910_ts {
struct input_dev *input;
struct timer_list timer;
int irq_num;
void __iomem *clocken;
void __iomem *ts_reg;
spinlock_t lock;
enum ts_state state;
};

static void w90p910_report_event(struct w90p910_ts *w90p910_ts, bool down)
{
struct input_dev *dev = w90p910_ts->input;

if (down) {
input_report_abs(dev, ABS_X,
__raw_readl(w90p910_ts->ts_reg + 0x0c));
input_report_abs(dev, ABS_Y,
__raw_readl(w90p910_ts->ts_reg + 0x10));
}

input_report_key(dev, BTN_TOUCH, down);
input_sync(dev);
}

static void w90p910_prepare_x_reading(struct w90p910_ts *w90p910_ts)
{
unsigned long ctlreg;

__raw_writel(ADC_TSC_X, w90p910_ts->ts_reg + 0x04);
ctlreg = __raw_readl(w90p910_ts->ts_reg);
ctlreg &= ~(ADC_WAITTRIG | WT_INT | WT_INT_EN);
ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
__raw_writel(ctlreg, w90p910_ts->ts_reg);

w90p910_ts->state = TS_WAIT_X_COORD;
}

static void w90p910_prepare_y_reading(struct w90p910_ts *w90p910_ts)
{
unsigned long ctlreg;

__raw_writel(ADC_TSC_Y, w90p910_ts->ts_reg + 0x04);
ctlreg = __raw_readl(w90p910_ts->ts_reg);
ctlreg &= ~(ADC_WAITTRIG | ADC_INT | WT_INT_EN);
ctlreg |= ADC_SEMIAUTO | ADC_INT_EN | ADC_CONV;
__raw_writel(ctlreg, w90p910_ts->ts_reg);

w90p910_ts->state = TS_WAIT_Y_COORD;
}

static void w90p910_prepare_next_packet(struct w90p910_ts *w90p910_ts)
{
unsigned long ctlreg;

ctlreg = __raw_readl(w90p910_ts->ts_reg);
ctlreg &= ~(ADC_INT | ADC_INT_EN | ADC_SEMIAUTO | ADC_CONV);
ctlreg |= ADC_WAITTRIG | WT_INT_EN;
__raw_writel(ctlreg, w90p910_ts->ts_reg);

w90p910_ts->state = TS_WAIT_NEW_PACKET;
}

static irqreturn_t w90p910_ts_interrupt(int irq, void *dev_id)
{
struct w90p910_ts *w90p910_ts = dev_id;
unsigned long flags;

spin_lock_irqsave(&w90p910_ts->lock, flags);

switch (w90p910_ts->state) {
case TS_WAIT_NEW_PACKET:
/*
* The controller only generates interrupts when pen
* is down.
*/
del_timer(&w90p910_ts->timer);
w90p910_prepare_x_reading(w90p910_ts);
break;


case TS_WAIT_X_COORD:
w90p910_prepare_y_reading(w90p910_ts);
break;

case TS_WAIT_Y_COORD:
w90p910_report_event(w90p910_ts, true);
w90p910_prepare_next_packet(w90p910_ts);
mod_timer(&w90p910_ts->timer, jiffies + msecs_to_jiffies(100));
break;

case TS_IDLE:
break;
}

spin_unlock_irqrestore(&w90p910_ts->lock, flags);

return IRQ_HANDLED;
}

static void w90p910_check_pen_up(unsigned long data)
{
struct w90p910_ts *w90p910_ts = (struct w90p910_ts *) data;
unsigned long flags;

spin_lock_irqsave(&w90p910_ts->lock, flags);

if (w90p910_ts->state == TS_WAIT_NEW_PACKET &&
!(__raw_readl(w90p910_ts->ts_reg + 0x04) & ADC_DOWN)) {

w90p910_report_event(w90p910_ts, false);
}

spin_unlock_irqrestore(&w90p910_ts->lock, flags);
}

static int w90p910_open(struct input_dev *dev)
{
struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
unsigned long val;

/* enable the ADC clock */
val = __raw_readl(w90p910_ts->clocken);
__raw_writel(val | ADC_CLK_EN, w90p910_ts->clocken);

__raw_writel(ADC_RST1, w90p910_ts->ts_reg);
msleep(1);
__raw_writel(ADC_RST0, w90p910_ts->ts_reg);
msleep(1);

/* set delay and screen type */
val = __raw_readl(w90p910_ts->ts_reg + 0x04);
__raw_writel(val & TSC_FOURWIRE, w90p910_ts->ts_reg + 0x04);
__raw_writel(ADC_DELAY, w90p910_ts->ts_reg + 0x08);

w90p910_ts->state = TS_WAIT_NEW_PACKET;
wmb();

/* set trigger mode */
val = __raw_readl(w90p910_ts->ts_reg);
val |= ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN;
__raw_writel(val, w90p910_ts->ts_reg);

return 0;
}

static void w90p910_close(struct input_dev *dev)
{
struct w90p910_ts *w90p910_ts = input_get_drvdata(dev);
unsigned long val;

/* disable trigger mode */

spin_lock_irq(&w90p910_ts->lock);

w90p910_ts->state = TS_IDLE;

val = __raw_readl(w90p910_ts->ts_reg);
val &= ~(ADC_WAITTRIG | ADC_DIV | ADC_EN | WT_INT_EN | ADC_INT_EN);
__raw_writel(val, w90p910_ts->ts_reg);

spin_unlock_irq(&w90p910_ts->lock);

/* Now that interrupts are shut off we can safely delete timer */
del_timer_sync(&w90p910_ts->timer);

/* stop the ADC clock */
val = __raw_readl(w90p910_ts->clocken);
__raw_writel(val & ~ADC_CLK_EN, w90p910_ts->clocken);
}

static int __devinit w90x900ts_probe(struct platform_device *pdev)
{
struct w90p910_ts *w90p910_ts;
struct input_dev *input_dev;
struct resource *res;
int err;

w90p910_ts = kzalloc(sizeof(struct w90p910_ts), GFP_KERNEL);
input_dev = input_allocate_device();
if (!w90p910_ts || !input_dev) {
err = -ENOMEM;
goto fail1;
}

w90p910_ts->input = input_dev;
w90p910_ts->state = TS_IDLE;
spin_lock_init(&w90p910_ts->lock);
setup_timer(&w90p910_ts->timer, w90p910_check_pen_up,
(unsigned long)&w90p910_ts);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
err = -ENXIO;
goto fail1;
}

if (!request_mem_region(res->start, res->end - res->start + 1,
pdev->name)) {
err = -EBUSY;
goto fail1;
}

w90p910_ts->ts_reg = ioremap(res->start, res->end - res->start + 1);
if (!w90p910_ts->ts_reg) {
err = -ENOMEM;
goto fail2;
}

res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
if (!res) {
err = -ENXIO;
goto fail3;
}

w90p910_ts->clocken = (void __iomem *)res->start;

input_dev->name = "W90P910 TouchScreen";
input_dev->phys = "w90p910ts/event0";
input_dev->id.bustype = BUS_HOST;
input_dev->id.vendor = 0x0005;
input_dev->id.product = 0x0001;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &pdev->dev;
input_dev->open = w90p910_open;
input_dev->close = w90p910_close;

input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);

input_set_abs_params(input_dev, ABS_X, 0, 0x400, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 0x400, 0, 0);

input_set_drvdata(input_dev, w90p910_ts);

w90p910_ts->irq_num = platform_get_irq(pdev, 0);
if (request_irq(w90p910_ts->irq_num, w90p910_ts_interrupt,
IRQF_DISABLED, "w90p910ts", w90p910_ts)) {
err = -EBUSY;
goto fail3;
}

err = input_register_device(w90p910_ts->input);
if (err)
goto fail4;

platform_set_drvdata(pdev, w90p910_ts);

return 0;

fail4: free_irq(w90p910_ts->irq_num, w90p910_ts);
fail3: iounmap(w90p910_ts->ts_reg);
fail2: release_mem_region(res->start, res->end - res->start + 1);
fail1: input_free_device(input_dev);
kfree(w90p910_ts);
return err;
}

static int __devexit w90x900ts_remove(struct platform_device *pdev)
{
struct w90p910_ts *w90p910_ts = platform_get_drvdata(pdev);
struct resource *res;

free_irq(w90p910_ts->irq_num, w90p910_ts);
del_timer_sync(&w90p910_ts->timer);
iounmap(w90p910_ts->ts_reg);

res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
release_mem_region(res->start, res->end - res->start + 1);

input_unregister_device(w90p910_ts->input);
kfree(w90p910_ts);

platform_set_drvdata(pdev, NULL);

return 0;
}

static struct platform_driver w90x900ts_driver = {
.probe = w90x900ts_probe,
.remove = __devexit_p(w90x900ts_remove),
.driver = {
.name = "w90x900-ts",
.owner = THIS_MODULE,
},
};

static int __init w90x900ts_init(void)
{
return platform_driver_register(&w90x900ts_driver);
}

static void __exit w90x900ts_exit(void)
{
platform_driver_unregister(&w90x900ts_driver);
}

module_init(w90x900ts_init);
module_exit(w90x900ts_exit);

MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("w90p910 touch screen driver!");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:w90p910-ts");

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