1
linux/drivers/input/touchscreen/mc13783_ts.c
Uwe Kleine-König 02fd95e114 Input: mc13783_ts - convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.
To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new() which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20230920125829.1478827-47-u.kleine-koenig@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-09-23 19:28:15 -07:00

241 lines
6.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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/
*/
#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;
unsigned int sample[4];
struct mc13xxx_ts_platform_data *touch;
};
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.
*/
schedule_delayed_work(&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);
schedule_delayed_work(&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->touch->ato, priv->touch->atox,
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;
priv->touch = dev_get_platdata(&pdev->dev);
if (!priv->touch) {
dev_err(&pdev->dev, "missing platform data\n");
ret = -ENODEV;
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_free_mem;
}
platform_set_drvdata(pdev, priv);
return 0;
err_free_mem:
input_free_device(idev);
kfree(priv);
return ret;
}
static void mc13783_ts_remove(struct platform_device *pdev)
{
struct mc13783_ts_priv *priv = platform_get_drvdata(pdev);
input_unregister_device(priv->idev);
kfree(priv);
}
static struct platform_driver mc13783_ts_driver = {
.remove_new = mc13783_ts_remove,
.driver = {
.name = MC13783_TS_NAME,
},
};
module_platform_driver_probe(mc13783_ts_driver, mc13783_ts_probe);
MODULE_DESCRIPTION("MC13783 input touchscreen driver");
MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" MC13783_TS_NAME);