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linux/drivers/input/touchscreen/tsc40.c
Erick Archer f81d03d439 Input: touchscreen - use sizeof(*pointer) instead of sizeof(type)
It is preferred to use sizeof(*pointer) instead of sizeof(type)
due to the type of the variable can change and one needs not
change the former (unlike the latter).

The refactoring is mostly trivial except for "usbtouchscreen.c"
file. Here, in the "mtouch_alloc" and "nexio_alloc" functions,
it is necessary to use a variable with a predefined type instead
of the "usbtouch->priv" variable (void * type). This way, the
"sizeof" operator can now know the correct size. Moreover, we
need to set the "usbtouch->priv" pointer after the memory
allocation since now the "kmalloc" return value is not assigned
directly.

This patch has no effect on runtime behavior.

Signed-off-by: Erick Archer <erick.archer@outlook.com>
Link: https://lore.kernel.org/r/AS8PR02MB723708364CC0DF2EAAFEE5968BC42@AS8PR02MB7237.eurprd02.prod.outlook.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2024-06-09 14:38:38 -07:00

173 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* TSC-40 serial touchscreen driver. It should be compatible with
* TSC-10 and 25.
*
* Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#define PACKET_LENGTH 5
struct tsc_ser {
struct input_dev *dev;
struct serio *serio;
u32 idx;
unsigned char data[PACKET_LENGTH];
char phys[32];
};
static void tsc_process_data(struct tsc_ser *ptsc)
{
struct input_dev *dev = ptsc->dev;
u8 *data = ptsc->data;
u32 x;
u32 y;
x = ((data[1] & 0x03) << 8) | data[2];
y = ((data[3] & 0x03) << 8) | data[4];
input_report_abs(dev, ABS_X, x);
input_report_abs(dev, ABS_Y, y);
input_report_key(dev, BTN_TOUCH, 1);
input_sync(dev);
}
static irqreturn_t tsc_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct tsc_ser *ptsc = serio_get_drvdata(serio);
struct input_dev *dev = ptsc->dev;
ptsc->data[ptsc->idx] = data;
switch (ptsc->idx++) {
case 0:
if (unlikely((data & 0x3e) != 0x10)) {
dev_dbg(&serio->dev,
"unsynchronized packet start (0x%02x)\n", data);
ptsc->idx = 0;
} else if (!(data & 0x01)) {
input_report_key(dev, BTN_TOUCH, 0);
input_sync(dev);
ptsc->idx = 0;
}
break;
case 1:
case 3:
if (unlikely(data & 0xfc)) {
dev_dbg(&serio->dev,
"unsynchronized data 0x%02x at offset %d\n",
data, ptsc->idx - 1);
ptsc->idx = 0;
}
break;
case 4:
tsc_process_data(ptsc);
ptsc->idx = 0;
break;
}
return IRQ_HANDLED;
}
static int tsc_connect(struct serio *serio, struct serio_driver *drv)
{
struct tsc_ser *ptsc;
struct input_dev *input_dev;
int error;
ptsc = kzalloc(sizeof(*ptsc), GFP_KERNEL);
input_dev = input_allocate_device();
if (!ptsc || !input_dev) {
error = -ENOMEM;
goto fail1;
}
ptsc->serio = serio;
ptsc->dev = input_dev;
snprintf(ptsc->phys, sizeof(ptsc->phys), "%s/input0", serio->phys);
input_dev->name = "TSC-10/25/40 Serial TouchScreen";
input_dev->phys = ptsc->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_TSC40;
input_dev->id.product = 40;
input_dev->id.version = 0x0001;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
__set_bit(BTN_TOUCH, input_dev->keybit);
input_set_abs_params(ptsc->dev, ABS_X, 0, 0x3ff, 0, 0);
input_set_abs_params(ptsc->dev, ABS_Y, 0, 0x3ff, 0, 0);
serio_set_drvdata(serio, ptsc);
error = serio_open(serio, drv);
if (error)
goto fail2;
error = input_register_device(ptsc->dev);
if (error)
goto fail3;
return 0;
fail3:
serio_close(serio);
fail2:
serio_set_drvdata(serio, NULL);
fail1:
input_free_device(input_dev);
kfree(ptsc);
return error;
}
static void tsc_disconnect(struct serio *serio)
{
struct tsc_ser *ptsc = serio_get_drvdata(serio);
serio_close(serio);
input_unregister_device(ptsc->dev);
kfree(ptsc);
serio_set_drvdata(serio, NULL);
}
static const struct serio_device_id tsc_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_TSC40,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, tsc_serio_ids);
#define DRIVER_DESC "TSC-10/25/40 serial touchscreen driver"
static struct serio_driver tsc_drv = {
.driver = {
.name = "tsc40",
},
.description = DRIVER_DESC,
.id_table = tsc_serio_ids,
.interrupt = tsc_interrupt,
.connect = tsc_connect,
.disconnect = tsc_disconnect,
};
module_serio_driver(tsc_drv);
MODULE_AUTHOR("Sebastian Andrzej Siewior <bigeasy@linutronix.de>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL v2");