257 lines
6.7 KiB
C
257 lines
6.7 KiB
C
/*
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* Driver for the Freescale Semiconductor MC13783 touchscreen.
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*
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* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
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* Copyright (C) 2009 Sascha Hauer, Pengutronix
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*
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* Initial development of this code was funded by
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* Phytec Messtechnik GmbH, http://www.phytec.de/
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*/
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#include <linux/platform_device.h>
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#include <linux/mfd/mc13783.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/input.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/init.h>
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#define MC13783_TS_NAME "mc13783-ts"
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#define DEFAULT_SAMPLE_TOLERANCE 300
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static unsigned int sample_tolerance = DEFAULT_SAMPLE_TOLERANCE;
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module_param(sample_tolerance, uint, S_IRUGO | S_IWUSR);
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MODULE_PARM_DESC(sample_tolerance,
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"If the minimal and maximal value read out for one axis (out "
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"of three) differ by this value (default: "
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__stringify(DEFAULT_SAMPLE_TOLERANCE) ") or more, the reading "
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"is supposed to be wrong and is discarded. Set to 0 to "
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"disable this check.");
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struct mc13783_ts_priv {
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struct input_dev *idev;
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struct mc13xxx *mc13xxx;
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struct delayed_work work;
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struct workqueue_struct *workq;
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unsigned int sample[4];
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struct mc13xxx_ts_platform_data *touch;
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};
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static irqreturn_t mc13783_ts_handler(int irq, void *data)
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{
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struct mc13783_ts_priv *priv = data;
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mc13xxx_irq_ack(priv->mc13xxx, irq);
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/*
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* Kick off reading coordinates. Note that if work happens already
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* be queued for future execution (it rearms itself) it will not
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* be rescheduled for immediate execution here. However the rearm
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* delay is HZ / 50 which is acceptable.
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*/
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queue_delayed_work(priv->workq, &priv->work, 0);
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return IRQ_HANDLED;
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}
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#define sort3(a0, a1, a2) ({ \
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if (a0 > a1) \
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swap(a0, a1); \
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if (a1 > a2) \
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swap(a1, a2); \
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if (a0 > a1) \
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swap(a0, a1); \
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})
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static void mc13783_ts_report_sample(struct mc13783_ts_priv *priv)
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{
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struct input_dev *idev = priv->idev;
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int x0, x1, x2, y0, y1, y2;
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int cr0, cr1;
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/*
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* the values are 10-bit wide only, but the two least significant
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* bits are for future 12 bit use and reading yields 0
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*/
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x0 = priv->sample[0] & 0xfff;
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x1 = priv->sample[1] & 0xfff;
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x2 = priv->sample[2] & 0xfff;
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y0 = priv->sample[3] & 0xfff;
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y1 = (priv->sample[0] >> 12) & 0xfff;
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y2 = (priv->sample[1] >> 12) & 0xfff;
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cr0 = (priv->sample[2] >> 12) & 0xfff;
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cr1 = (priv->sample[3] >> 12) & 0xfff;
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dev_dbg(&idev->dev,
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"x: (% 4d,% 4d,% 4d) y: (% 4d, % 4d,% 4d) cr: (% 4d, % 4d)\n",
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x0, x1, x2, y0, y1, y2, cr0, cr1);
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sort3(x0, x1, x2);
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sort3(y0, y1, y2);
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cr0 = (cr0 + cr1) / 2;
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if (!cr0 || !sample_tolerance ||
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(x2 - x0 < sample_tolerance &&
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y2 - y0 < sample_tolerance)) {
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/* report the median coordinate and average pressure */
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if (cr0) {
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input_report_abs(idev, ABS_X, x1);
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input_report_abs(idev, ABS_Y, y1);
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dev_dbg(&idev->dev, "report (%d, %d, %d)\n",
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x1, y1, 0x1000 - cr0);
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queue_delayed_work(priv->workq, &priv->work, HZ / 50);
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} else
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dev_dbg(&idev->dev, "report release\n");
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input_report_abs(idev, ABS_PRESSURE,
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cr0 ? 0x1000 - cr0 : cr0);
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input_report_key(idev, BTN_TOUCH, cr0);
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input_sync(idev);
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} else
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dev_dbg(&idev->dev, "discard event\n");
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}
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static void mc13783_ts_work(struct work_struct *work)
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{
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struct mc13783_ts_priv *priv =
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container_of(work, struct mc13783_ts_priv, work.work);
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unsigned int mode = MC13XXX_ADC_MODE_TS;
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unsigned int channel = 12;
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if (mc13xxx_adc_do_conversion(priv->mc13xxx,
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mode, channel,
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priv->touch->ato, priv->touch->atox,
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priv->sample) == 0)
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mc13783_ts_report_sample(priv);
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}
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static int mc13783_ts_open(struct input_dev *dev)
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{
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struct mc13783_ts_priv *priv = input_get_drvdata(dev);
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int ret;
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mc13xxx_lock(priv->mc13xxx);
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mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TS);
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ret = mc13xxx_irq_request(priv->mc13xxx, MC13XXX_IRQ_TS,
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mc13783_ts_handler, MC13783_TS_NAME, priv);
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if (ret)
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goto out;
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ret = mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
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MC13XXX_ADC0_TSMOD_MASK, MC13XXX_ADC0_TSMOD0);
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if (ret)
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mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
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out:
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mc13xxx_unlock(priv->mc13xxx);
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return ret;
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}
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static void mc13783_ts_close(struct input_dev *dev)
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{
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struct mc13783_ts_priv *priv = input_get_drvdata(dev);
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mc13xxx_lock(priv->mc13xxx);
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mc13xxx_reg_rmw(priv->mc13xxx, MC13XXX_ADC0,
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MC13XXX_ADC0_TSMOD_MASK, 0);
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mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TS, priv);
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mc13xxx_unlock(priv->mc13xxx);
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cancel_delayed_work_sync(&priv->work);
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}
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static int __init mc13783_ts_probe(struct platform_device *pdev)
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{
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struct mc13783_ts_priv *priv;
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struct input_dev *idev;
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int ret = -ENOMEM;
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priv = kzalloc(sizeof(*priv), GFP_KERNEL);
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idev = input_allocate_device();
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if (!priv || !idev)
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goto err_free_mem;
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INIT_DELAYED_WORK(&priv->work, mc13783_ts_work);
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priv->mc13xxx = dev_get_drvdata(pdev->dev.parent);
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priv->idev = idev;
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priv->touch = dev_get_platdata(&pdev->dev);
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if (!priv->touch) {
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dev_err(&pdev->dev, "missing platform data\n");
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ret = -ENODEV;
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goto err_free_mem;
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}
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/*
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* We need separate workqueue because mc13783_adc_do_conversion
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* uses keventd and thus would deadlock.
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*/
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priv->workq = create_singlethread_workqueue("mc13783_ts");
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if (!priv->workq)
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goto err_free_mem;
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idev->name = MC13783_TS_NAME;
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idev->dev.parent = &pdev->dev;
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idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
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idev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
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input_set_abs_params(idev, ABS_X, 0, 0xfff, 0, 0);
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input_set_abs_params(idev, ABS_Y, 0, 0xfff, 0, 0);
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input_set_abs_params(idev, ABS_PRESSURE, 0, 0xfff, 0, 0);
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idev->open = mc13783_ts_open;
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idev->close = mc13783_ts_close;
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input_set_drvdata(idev, priv);
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ret = input_register_device(priv->idev);
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if (ret) {
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dev_err(&pdev->dev,
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"register input device failed with %d\n", ret);
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goto err_destroy_wq;
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}
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platform_set_drvdata(pdev, priv);
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return 0;
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err_destroy_wq:
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destroy_workqueue(priv->workq);
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err_free_mem:
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input_free_device(idev);
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kfree(priv);
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return ret;
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}
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static int mc13783_ts_remove(struct platform_device *pdev)
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{
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struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
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destroy_workqueue(priv->workq);
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input_unregister_device(priv->idev);
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kfree(priv);
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return 0;
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}
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static struct platform_driver mc13783_ts_driver = {
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.remove = mc13783_ts_remove,
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.driver = {
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.owner = THIS_MODULE,
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.name = MC13783_TS_NAME,
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},
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};
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module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe);
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MODULE_DESCRIPTION("MC13783 input touchscreen driver");
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MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:" MC13783_TS_NAME);
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