drivers/input/touchscreen/mc13783_ts.c - kernel/bruno - Git at Google

 /*
  * 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 mc13783 *mc13783;
 	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;

 	mc13783_irq_ack(priv->mc13783, 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 = MC13783_ADC_MODE_TS;
 	unsigned int channel = 12;

 	if (mc13783_adc_do_conversion(priv->mc13783,
 				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;

 	mc13783_lock(priv->mc13783);

 	mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TS);

 	ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS,
 		mc13783_ts_handler, MC13783_TS_NAME, priv);
 	if (ret)
 		goto out;

 	ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
 			MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
 	if (ret)
 		mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
 out:
 	mc13783_unlock(priv->mc13783);
 	return ret;
 }

 static void mc13783_ts_close(struct input_dev *dev)
 {
 	struct mc13783_ts_priv *priv = input_get_drvdata(dev);

 	mc13783_lock(priv->mc13783);
 	mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
 			MC13783_ADC0_TSMOD_MASK, 0);
 	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
 	mc13783_unlock(priv->mc13783);

 	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->mc13783 = 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,
 	},
 };

 static int __init mc13783_ts_init(void)
 {
 	return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
 }
 module_init(mc13783_ts_init);

 static void __exit mc13783_ts_exit(void)
 {
 	platform_driver_unregister(&mc13783_ts_driver);
 }
 module_exit(mc13783_ts_exit);

 MODULE_DESCRIPTION("MC13783 input touchscreen driver");
 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:" MC13783_TS_NAME);
	/*
	* 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 mc13783 *mc13783;
	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;

	mc13783_irq_ack(priv->mc13783, 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 = MC13783_ADC_MODE_TS;
	unsigned int channel = 12;

	if (mc13783_adc_do_conversion(priv->mc13783,
	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;

	mc13783_lock(priv->mc13783);

	mc13783_irq_ack(priv->mc13783, MC13783_IRQ_TS);

	ret = mc13783_irq_request(priv->mc13783, MC13783_IRQ_TS,
	mc13783_ts_handler, MC13783_TS_NAME, priv);
	if (ret)
	goto out;

	ret = mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
	MC13783_ADC0_TSMOD_MASK, MC13783_ADC0_TSMOD0);
	if (ret)
	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
	out:
	mc13783_unlock(priv->mc13783);
	return ret;
	}

	static void mc13783_ts_close(struct input_dev *dev)
	{
	struct mc13783_ts_priv *priv = input_get_drvdata(dev);

	mc13783_lock(priv->mc13783);
	mc13783_reg_rmw(priv->mc13783, MC13783_ADC0,
	MC13783_ADC0_TSMOD_MASK, 0);
	mc13783_irq_free(priv->mc13783, MC13783_IRQ_TS, priv);
	mc13783_unlock(priv->mc13783);

	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->mc13783 = 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,
	},
	};

	static int __init mc13783_ts_init(void)
	{
	return platform_driver_probe(&mc13783_ts_driver, &mc13783_ts_probe);
	}
	module_init(mc13783_ts_init);

	static void __exit mc13783_ts_exit(void)
	{
	platform_driver_unregister(&mc13783_ts_driver);
	}
	module_exit(mc13783_ts_exit);

	MODULE_DESCRIPTION("MC13783 input touchscreen driver");
	MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:" MC13783_TS_NAME);