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linux/drivers/input/touchscreen/wm831x-ts.c
Uwe Kleine-König 33984b4f42 Input: wm831x-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>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20230920125829.1478827-52-u.kleine-koenig@pengutronix.de
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2023-09-23 19:28:17 -07:00

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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Touchscreen driver for WM831x PMICs
*
* Copyright 2011 Wolfson Microelectronics plc.
* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/irq.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/types.h>
/*
* R16424 (0x4028) - Touch Control 1
*/
#define WM831X_TCH_ENA 0x8000 /* TCH_ENA */
#define WM831X_TCH_CVT_ENA 0x4000 /* TCH_CVT_ENA */
#define WM831X_TCH_SLPENA 0x1000 /* TCH_SLPENA */
#define WM831X_TCH_Z_ENA 0x0400 /* TCH_Z_ENA */
#define WM831X_TCH_Y_ENA 0x0200 /* TCH_Y_ENA */
#define WM831X_TCH_X_ENA 0x0100 /* TCH_X_ENA */
#define WM831X_TCH_DELAY_MASK 0x00E0 /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_SHIFT 5 /* TCH_DELAY - [7:5] */
#define WM831X_TCH_DELAY_WIDTH 3 /* TCH_DELAY - [7:5] */
#define WM831X_TCH_RATE_MASK 0x001F /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_SHIFT 0 /* TCH_RATE - [4:0] */
#define WM831X_TCH_RATE_WIDTH 5 /* TCH_RATE - [4:0] */
/*
* R16425 (0x4029) - Touch Control 2
*/
#define WM831X_TCH_PD_WK 0x2000 /* TCH_PD_WK */
#define WM831X_TCH_5WIRE 0x1000 /* TCH_5WIRE */
#define WM831X_TCH_PDONLY 0x0800 /* TCH_PDONLY */
#define WM831X_TCH_ISEL 0x0100 /* TCH_ISEL */
#define WM831X_TCH_RPU_MASK 0x000F /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_SHIFT 0 /* TCH_RPU - [3:0] */
#define WM831X_TCH_RPU_WIDTH 4 /* TCH_RPU - [3:0] */
/*
* R16426-8 (0x402A-C) - Touch Data X/Y/X
*/
#define WM831X_TCH_PD 0x8000 /* TCH_PD1 */
#define WM831X_TCH_DATA_MASK 0x0FFF /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_SHIFT 0 /* TCH_DATA - [11:0] */
#define WM831X_TCH_DATA_WIDTH 12 /* TCH_DATA - [11:0] */
struct wm831x_ts {
struct input_dev *input_dev;
struct wm831x *wm831x;
unsigned int data_irq;
unsigned int pd_irq;
bool pressure;
bool pen_down;
struct work_struct pd_data_work;
};
static void wm831x_pd_data_work(struct work_struct *work)
{
struct wm831x_ts *wm831x_ts =
container_of(work, struct wm831x_ts, pd_data_work);
if (wm831x_ts->pen_down) {
enable_irq(wm831x_ts->data_irq);
dev_dbg(wm831x_ts->wm831x->dev, "IRQ PD->DATA done\n");
} else {
enable_irq(wm831x_ts->pd_irq);
dev_dbg(wm831x_ts->wm831x->dev, "IRQ DATA->PD done\n");
}
}
static irqreturn_t wm831x_ts_data_irq(int irq, void *irq_data)
{
struct wm831x_ts *wm831x_ts = irq_data;
struct wm831x *wm831x = wm831x_ts->wm831x;
static int data_types[] = { ABS_X, ABS_Y, ABS_PRESSURE };
u16 data[3];
int count;
int i, ret;
if (wm831x_ts->pressure)
count = 3;
else
count = 2;
wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
ret = wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count,
data);
if (ret != 0) {
dev_err(wm831x->dev, "Failed to read touch data: %d\n",
ret);
return IRQ_NONE;
}
/*
* We get a pen down reading on every reading, report pen up if any
* individual reading does so.
*/
wm831x_ts->pen_down = true;
for (i = 0; i < count; i++) {
if (!(data[i] & WM831X_TCH_PD)) {
wm831x_ts->pen_down = false;
continue;
}
input_report_abs(wm831x_ts->input_dev, data_types[i],
data[i] & WM831X_TCH_DATA_MASK);
}
if (!wm831x_ts->pen_down) {
/* Switch from data to pen down */
dev_dbg(wm831x->dev, "IRQ DATA->PD\n");
disable_irq_nosync(wm831x_ts->data_irq);
/* Don't need data any more */
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
WM831X_TCH_Z_ENA, 0);
/* Flush any final samples that arrived while reading */
wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
WM831X_TCHDATA_EINT, WM831X_TCHDATA_EINT);
wm831x_bulk_read(wm831x, WM831X_TOUCH_DATA_X, count, data);
if (wm831x_ts->pressure)
input_report_abs(wm831x_ts->input_dev,
ABS_PRESSURE, 0);
input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 0);
schedule_work(&wm831x_ts->pd_data_work);
} else {
input_report_key(wm831x_ts->input_dev, BTN_TOUCH, 1);
}
input_sync(wm831x_ts->input_dev);
return IRQ_HANDLED;
}
static irqreturn_t wm831x_ts_pen_down_irq(int irq, void *irq_data)
{
struct wm831x_ts *wm831x_ts = irq_data;
struct wm831x *wm831x = wm831x_ts->wm831x;
int ena = 0;
if (wm831x_ts->pen_down)
return IRQ_HANDLED;
disable_irq_nosync(wm831x_ts->pd_irq);
/* Start collecting data */
if (wm831x_ts->pressure)
ena |= WM831X_TCH_Z_ENA;
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA,
WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA | ena);
wm831x_set_bits(wm831x, WM831X_INTERRUPT_STATUS_1,
WM831X_TCHPD_EINT, WM831X_TCHPD_EINT);
wm831x_ts->pen_down = true;
/* Switch from pen down to data */
dev_dbg(wm831x->dev, "IRQ PD->DATA\n");
schedule_work(&wm831x_ts->pd_data_work);
return IRQ_HANDLED;
}
static int wm831x_ts_input_open(struct input_dev *idev)
{
struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
struct wm831x *wm831x = wm831x_ts->wm831x;
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_ENA | WM831X_TCH_CVT_ENA |
WM831X_TCH_X_ENA | WM831X_TCH_Y_ENA |
WM831X_TCH_Z_ENA, WM831X_TCH_ENA);
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_CVT_ENA, WM831X_TCH_CVT_ENA);
return 0;
}
static void wm831x_ts_input_close(struct input_dev *idev)
{
struct wm831x_ts *wm831x_ts = input_get_drvdata(idev);
struct wm831x *wm831x = wm831x_ts->wm831x;
/* Shut the controller down, disabling all other functionality too */
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_ENA | WM831X_TCH_X_ENA |
WM831X_TCH_Y_ENA | WM831X_TCH_Z_ENA, 0);
/* Make sure any pending IRQs are done, the above will prevent
* new ones firing.
*/
synchronize_irq(wm831x_ts->data_irq);
synchronize_irq(wm831x_ts->pd_irq);
/* Make sure the IRQ completion work is quiesced */
flush_work(&wm831x_ts->pd_data_work);
/* If we ended up with the pen down then make sure we revert back
* to pen detection state for the next time we start up.
*/
if (wm831x_ts->pen_down) {
disable_irq(wm831x_ts->data_irq);
enable_irq(wm831x_ts->pd_irq);
wm831x_ts->pen_down = false;
}
}
static int wm831x_ts_probe(struct platform_device *pdev)
{
struct wm831x_ts *wm831x_ts;
struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
struct wm831x_pdata *core_pdata = dev_get_platdata(pdev->dev.parent);
struct wm831x_touch_pdata *pdata = NULL;
struct input_dev *input_dev;
int error, irqf;
if (core_pdata)
pdata = core_pdata->touch;
wm831x_ts = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_ts),
GFP_KERNEL);
input_dev = devm_input_allocate_device(&pdev->dev);
if (!wm831x_ts || !input_dev) {
error = -ENOMEM;
goto err_alloc;
}
wm831x_ts->wm831x = wm831x;
wm831x_ts->input_dev = input_dev;
INIT_WORK(&wm831x_ts->pd_data_work, wm831x_pd_data_work);
/*
* If we have a direct IRQ use it, otherwise use the interrupt
* from the WM831x IRQ controller.
*/
wm831x_ts->data_irq = wm831x_irq(wm831x,
platform_get_irq_byname(pdev,
"TCHDATA"));
if (pdata && pdata->data_irq)
wm831x_ts->data_irq = pdata->data_irq;
wm831x_ts->pd_irq = wm831x_irq(wm831x,
platform_get_irq_byname(pdev, "TCHPD"));
if (pdata && pdata->pd_irq)
wm831x_ts->pd_irq = pdata->pd_irq;
if (pdata)
wm831x_ts->pressure = pdata->pressure;
else
wm831x_ts->pressure = true;
/* Five wire touchscreens can't report pressure */
if (pdata && pdata->fivewire) {
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
WM831X_TCH_5WIRE, WM831X_TCH_5WIRE);
/* Pressure measurements are not possible for five wire mode */
WARN_ON(pdata->pressure && pdata->fivewire);
wm831x_ts->pressure = false;
} else {
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
WM831X_TCH_5WIRE, 0);
}
if (pdata) {
switch (pdata->isel) {
default:
dev_err(&pdev->dev, "Unsupported ISEL setting: %d\n",
pdata->isel);
fallthrough;
case 200:
case 0:
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
WM831X_TCH_ISEL, 0);
break;
case 400:
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
WM831X_TCH_ISEL, WM831X_TCH_ISEL);
break;
}
}
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_2,
WM831X_TCH_PDONLY, 0);
/* Default to 96 samples/sec */
wm831x_set_bits(wm831x, WM831X_TOUCH_CONTROL_1,
WM831X_TCH_RATE_MASK, 6);
if (pdata && pdata->data_irqf)
irqf = pdata->data_irqf;
else
irqf = IRQF_TRIGGER_HIGH;
error = request_threaded_irq(wm831x_ts->data_irq,
NULL, wm831x_ts_data_irq,
irqf | IRQF_ONESHOT | IRQF_NO_AUTOEN,
"Touchscreen data", wm831x_ts);
if (error) {
dev_err(&pdev->dev, "Failed to request data IRQ %d: %d\n",
wm831x_ts->data_irq, error);
goto err_alloc;
}
if (pdata && pdata->pd_irqf)
irqf = pdata->pd_irqf;
else
irqf = IRQF_TRIGGER_HIGH;
error = request_threaded_irq(wm831x_ts->pd_irq,
NULL, wm831x_ts_pen_down_irq,
irqf | IRQF_ONESHOT,
"Touchscreen pen down", wm831x_ts);
if (error) {
dev_err(&pdev->dev, "Failed to request pen down IRQ %d: %d\n",
wm831x_ts->pd_irq, error);
goto err_data_irq;
}
/* set up touch configuration */
input_dev->name = "WM831x touchscreen";
input_dev->phys = "wm831x";
input_dev->open = wm831x_ts_input_open;
input_dev->close = wm831x_ts_input_close;
__set_bit(EV_ABS, input_dev->evbit);
__set_bit(EV_KEY, input_dev->evbit);
__set_bit(BTN_TOUCH, input_dev->keybit);
input_set_abs_params(input_dev, ABS_X, 0, 4095, 5, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 4095, 5, 0);
if (wm831x_ts->pressure)
input_set_abs_params(input_dev, ABS_PRESSURE, 0, 4095, 5, 0);
input_set_drvdata(input_dev, wm831x_ts);
input_dev->dev.parent = &pdev->dev;
error = input_register_device(input_dev);
if (error)
goto err_pd_irq;
platform_set_drvdata(pdev, wm831x_ts);
return 0;
err_pd_irq:
free_irq(wm831x_ts->pd_irq, wm831x_ts);
err_data_irq:
free_irq(wm831x_ts->data_irq, wm831x_ts);
err_alloc:
return error;
}
static void wm831x_ts_remove(struct platform_device *pdev)
{
struct wm831x_ts *wm831x_ts = platform_get_drvdata(pdev);
free_irq(wm831x_ts->pd_irq, wm831x_ts);
free_irq(wm831x_ts->data_irq, wm831x_ts);
}
static struct platform_driver wm831x_ts_driver = {
.driver = {
.name = "wm831x-touch",
},
.probe = wm831x_ts_probe,
.remove_new = wm831x_ts_remove,
};
module_platform_driver(wm831x_ts_driver);
/* Module information */
MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
MODULE_DESCRIPTION("WM831x PMIC touchscreen driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-touch");
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