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/*
* Driver for the Freescale Semiconductor MC13783 touchscreen.
*
* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright (C) 2009 Sascha Hauer, Pengutronix
*
* Initial development of this code was funded by
* Phytec Messtechnik GmbH, http://www.phytec.de/
*
* 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/platform_device.h>
#include <linux/mfd/mc13783.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/input.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/init.h>
#define MC13783_TS_NAME "mc13783-ts"
#define DEFAULT_SAMPLE_TOLERANCE 300
static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(sample_tolerance,
"If the minimal and maximal value read out for one axis (out "
"of three) differ by this value (default: "
__stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
"is supposed to be wrong and is discarded. Set to 0 to "
"disable this check.");
struct mc13783_ts_priv {
struct input_dev *idev;
struct mc13xxx *mc13xxx;
struct delayed_work work;
struct workqueue_struct *workq;
unsigned int sample[4];
};
static irqreturn_t mc13783_ts_handler(int irq, void *data)
{
struct mc13783_ts_priv *priv = data;
mc13xxx_irq_ack(priv->mc13xxx, irq);
/*
* Kick off reading coordinates. Note that if work happens already
* be queued for future execution (it rearms itself) it will not
* be rescheduled for immediate execution here. However the rearm
* delay is HZ / 50 which is acceptable.
*/
queue_delayed_work(priv->workq, &priv->work, 0);
return IRQ_HANDLED;
}
#define sort3(a0, a1, a2) ({ \
if (a0 > a1) \
swap(a0, a1); \
if (a1 > a2) \
swap(a1, a2); \
if (a0 > a1) \
swap(a0, a1); \
})
static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
{
struct input_dev *idev = priv->idev;
int x0, x1, x2, y0, y1, y2;
int cr0, cr1;
/*
* the values are 10-bit wide only, but the two least significant
* bits are for future 12 bit use and reading yields 0
*/
x0 = priv->sample[0] & 0xfff;
x1 = priv->sample[1] & 0xfff;
x2 = priv->sample[2] & 0xfff;
y0 = priv->sample[3] & 0xfff;
y1 = (priv->sample[0] >> 12) & 0xfff;
y2 = (priv->sample[1] >> 12) & 0xfff;
cr0 = (priv->sample[2] >> 12) & 0xfff;
cr1 = (priv->sample[3] >> 12) & 0xfff;
dev_dbg(&idev->dev,
"x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
x0, x1, x2, y0, y1, y2, cr0, cr1);
sort3(x0, x1, x2);
sort3(y0, y1, y2);
cr0 = (cr0 + cr1) / 2;
if (!cr0 || !sample_tolerance ||
(x2 - x0 < sample_tolerance &&
y2 - y0 < sample_tolerance)) {
/* report the median coordinate and average pressure */
if (cr0) {
input_report_abs(idev, ABS_X, x1);
input_report_abs(idev, ABS_Y, y1);
dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
x1, y1, 0x1000 - cr0);
queue_delayed_work(priv->workq, &priv->work, HZ / 50);
} else
dev_dbg(&idev->dev, "report release\n");
input_report_abs(idev, ABS_PRESSURE,
cr0 ? 0x1000 - cr0 : cr0);
input_report_key(idev, BTN_TOUCH, cr0);
input_sync(idev);
} else
dev_dbg(&idev->dev, "discard event\n");
}
static void mc13783_ts_work(struct work_struct *work)
{
struct mc13783_ts_priv *priv =
container_of(work, struct mc13783_ts_priv, work.work);
unsigned int mode = MC13XXX_ADC_MODE_TS;
unsigned int channel = 12;
if (mc13xxx_adc_do_conversion(priv->mc13xxx,
mode, channel, priv->sample) == 0)
mc13783_ts_report_sample(priv);
}
static int mc13783_ts_open(struct input_dev *dev)
{
struct mc13783_ts_priv *priv = input_get_drvdata(dev);
int ret;
mc13xxx_lock(priv->mc13xxx);
mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS);
ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS,
mc13783_ts_handler, MC13783_TS_NAME, priv);
if (ret)
goto out;
ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0);
if (ret)
mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
out:
mc13xxx_unlock(priv->mc13xxx);
return ret;
}
static void mc13783_ts_close(struct input_dev *dev)
{
struct mc13783_ts_priv *priv = input_get_drvdata(dev);
mc13xxx_lock(priv->mc13xxx);
mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
MC13XXX_ADC0_TSMOD_MASK, 0);
mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
mc13xxx_unlock(priv->mc13xxx);
cancel_delayed_work_sync(&priv->work);
}
static int __init mc13783_ts_probe(struct platform_device *pdev)
{
struct mc13783_ts_priv *priv;
struct input_dev *idev;
int ret = -ENOMEM;
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
idev = input_allocate_device();
if (!priv || !idev)
goto err_free_mem;
INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
priv->idev = idev;
/*
* We need separate workqueue because mc13783_adc_do_conversion
* uses keventd and thus would deadlock.
*/
priv->workq = create_singlethread_workqueue("mc13783_ts");
if (!priv->workq)
goto err_free_mem;
idev->name = MC13783_TS_NAME;
idev->dev.parent = &pdev->dev;
idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0);
idev->open = mc13783_ts_open;
idev->close = mc13783_ts_close;
input_set_drvdata(idev, priv);
ret = input_register_device(priv->idev);
if (ret) {
dev_err(&pdev->dev,
"register input device failed with %d\n", ret);
goto err_destroy_wq;
}
platform_set_drvdata(pdev, priv);
return 0;
err_destroy_wq:
destroy_workqueue(priv->workq);
err_free_mem:
input_free_device(idev);
kfree(priv);
return ret;
}
static int __devexit mc13783_ts_remove(struct platform_device *pdev)
{
struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL);
destroy_workqueue(priv->workq);
input_unregister_device(priv->idev);
kfree(priv);
return 0;
}
static struct platform_driver mc13783_ts_driver = {
.remove = __devexit_p(mc13783_ts_remove),
.driver = {
.owner = THIS_MODULE,
.name = MC13783_TS_NAME,
},
};
module_platform_driver(mc13783_ts_driver);
MODULE_DESCRIPTION("MC13783 input touchscreen driver");
MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" MC13783_TS_NAME);
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