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linux/drivers/input/touchscreen/elo.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

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Elo serial touchscreen driver
*
* Copyright (c) 2004 Vojtech Pavlik
*/
/*
* This driver can handle serial Elo touchscreens using either the Elo standard
* 'E271-2210' 10-byte protocol, Elo legacy 'E281A-4002' 6-byte protocol, Elo
* legacy 'E271-140' 4-byte protocol and Elo legacy 'E261-280' 3-byte protocol.
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/serio.h>
#include <linux/ctype.h>
#define DRIVER_DESC "Elo serial touchscreen driver"
MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_LICENSE("GPL");
/*
* Definitions & global arrays.
*/
#define ELO_MAX_LENGTH 10
#define ELO10_PACKET_LEN 8
#define ELO10_TOUCH 0x03
#define ELO10_PRESSURE 0x80
#define ELO10_LEAD_BYTE 'U'
#define ELO10_ID_CMD 'i'
#define ELO10_TOUCH_PACKET 'T'
#define ELO10_ACK_PACKET 'A'
#define ELI10_ID_PACKET 'I'
/*
* Per-touchscreen data.
*/
struct elo {
struct input_dev *dev;
struct serio *serio;
struct mutex cmd_mutex;
struct completion cmd_done;
int id;
int idx;
unsigned char expected_packet;
unsigned char csum;
unsigned char data[ELO_MAX_LENGTH];
unsigned char response[ELO10_PACKET_LEN];
char phys[32];
};
static void elo_process_data_10(struct elo *elo, unsigned char data)
{
struct input_dev *dev = elo->dev;
elo->data[elo->idx] = data;
switch (elo->idx++) {
case 0:
elo->csum = 0xaa;
if (data != ELO10_LEAD_BYTE) {
dev_dbg(&elo->serio->dev,
"unsynchronized data: 0x%02x\n", data);
elo->idx = 0;
}
break;
case 9:
elo->idx = 0;
if (data != elo->csum) {
dev_dbg(&elo->serio->dev,
"bad checksum: 0x%02x, expected 0x%02x\n",
data, elo->csum);
break;
}
if (elo->data[1] != elo->expected_packet) {
if (elo->data[1] != ELO10_TOUCH_PACKET)
dev_dbg(&elo->serio->dev,
"unexpected packet: 0x%02x\n",
elo->data[1]);
break;
}
if (likely(elo->data[1] == ELO10_TOUCH_PACKET)) {
input_report_abs(dev, ABS_X, (elo->data[4] << 8) | elo->data[3]);
input_report_abs(dev, ABS_Y, (elo->data[6] << 8) | elo->data[5]);
if (elo->data[2] & ELO10_PRESSURE)
input_report_abs(dev, ABS_PRESSURE,
(elo->data[8] << 8) | elo->data[7]);
input_report_key(dev, BTN_TOUCH, elo->data[2] & ELO10_TOUCH);
input_sync(dev);
} else if (elo->data[1] == ELO10_ACK_PACKET) {
if (elo->data[2] == '0')
elo->expected_packet = ELO10_TOUCH_PACKET;
complete(&elo->cmd_done);
} else {
memcpy(elo->response, &elo->data[1], ELO10_PACKET_LEN);
elo->expected_packet = ELO10_ACK_PACKET;
}
break;
}
elo->csum += data;
}
static void elo_process_data_6(struct elo *elo, unsigned char data)
{
struct input_dev *dev = elo->dev;
elo->data[elo->idx] = data;
switch (elo->idx++) {
case 0:
if ((data & 0xc0) != 0xc0)
elo->idx = 0;
break;
case 1:
if ((data & 0xc0) != 0x80)
elo->idx = 0;
break;
case 2:
if ((data & 0xc0) != 0x40)
elo->idx = 0;
break;
case 3:
if (data & 0xc0) {
elo->idx = 0;
break;
}
input_report_abs(dev, ABS_X, ((elo->data[0] & 0x3f) << 6) | (elo->data[1] & 0x3f));
input_report_abs(dev, ABS_Y, ((elo->data[2] & 0x3f) << 6) | (elo->data[3] & 0x3f));
if (elo->id == 2) {
input_report_key(dev, BTN_TOUCH, 1);
input_sync(dev);
elo->idx = 0;
}
break;
case 4:
if (data) {
input_sync(dev);
elo->idx = 0;
}
break;
case 5:
if ((data & 0xf0) == 0) {
input_report_abs(dev, ABS_PRESSURE, elo->data[5]);
input_report_key(dev, BTN_TOUCH, !!elo->data[5]);
}
input_sync(dev);
elo->idx = 0;
break;
}
}
static void elo_process_data_3(struct elo *elo, unsigned char data)
{
struct input_dev *dev = elo->dev;
elo->data[elo->idx] = data;
switch (elo->idx++) {
case 0:
if ((data & 0x7f) != 0x01)
elo->idx = 0;
break;
case 2:
input_report_key(dev, BTN_TOUCH, !(elo->data[1] & 0x80));
input_report_abs(dev, ABS_X, elo->data[1]);
input_report_abs(dev, ABS_Y, elo->data[2]);
input_sync(dev);
elo->idx = 0;
break;
}
}
static irqreturn_t elo_interrupt(struct serio *serio,
unsigned char data, unsigned int flags)
{
struct elo *elo = serio_get_drvdata(serio);
switch (elo->id) {
case 0:
elo_process_data_10(elo, data);
break;
case 1:
case 2:
elo_process_data_6(elo, data);
break;
case 3:
elo_process_data_3(elo, data);
break;
}
return IRQ_HANDLED;
}
static int elo_command_10(struct elo *elo, unsigned char *packet)
{
int rc = -1;
int i;
unsigned char csum = 0xaa + ELO10_LEAD_BYTE;
mutex_lock(&elo->cmd_mutex);
serio_pause_rx(elo->serio);
elo->expected_packet = toupper(packet[0]);
init_completion(&elo->cmd_done);
serio_continue_rx(elo->serio);
if (serio_write(elo->serio, ELO10_LEAD_BYTE))
goto out;
for (i = 0; i < ELO10_PACKET_LEN; i++) {
csum += packet[i];
if (serio_write(elo->serio, packet[i]))
goto out;
}
if (serio_write(elo->serio, csum))
goto out;
wait_for_completion_timeout(&elo->cmd_done, HZ);
if (elo->expected_packet == ELO10_TOUCH_PACKET) {
/* We are back in reporting mode, the command was ACKed */
memcpy(packet, elo->response, ELO10_PACKET_LEN);
rc = 0;
}
out:
mutex_unlock(&elo->cmd_mutex);
return rc;
}
static int elo_setup_10(struct elo *elo)
{
static const char *elo_types[] = { "Accu", "Dura", "Intelli", "Carroll" };
struct input_dev *dev = elo->dev;
unsigned char packet[ELO10_PACKET_LEN] = { ELO10_ID_CMD };
if (elo_command_10(elo, packet))
return -1;
dev->id.version = (packet[5] << 8) | packet[4];
input_set_abs_params(dev, ABS_X, 96, 4000, 0, 0);
input_set_abs_params(dev, ABS_Y, 96, 4000, 0, 0);
if (packet[3] & ELO10_PRESSURE)
input_set_abs_params(dev, ABS_PRESSURE, 0, 255, 0, 0);
dev_info(&elo->serio->dev,
"%sTouch touchscreen, fw: %02x.%02x, features: 0x%02x, controller: 0x%02x\n",
elo_types[(packet[1] -'0') & 0x03],
packet[5], packet[4], packet[3], packet[7]);
return 0;
}
/*
* elo_disconnect() is the opposite of elo_connect()
*/
static void elo_disconnect(struct serio *serio)
{
struct elo *elo = serio_get_drvdata(serio);
input_get_device(elo->dev);
input_unregister_device(elo->dev);
serio_close(serio);
serio_set_drvdata(serio, NULL);
input_put_device(elo->dev);
kfree(elo);
}
/*
* elo_connect() is the routine that is called when someone adds a
* new serio device that supports Gunze protocol and registers it as
* an input device.
*/
static int elo_connect(struct serio *serio, struct serio_driver *drv)
{
struct elo *elo;
struct input_dev *input_dev;
int err;
elo = kzalloc(sizeof(*elo), GFP_KERNEL);
input_dev = input_allocate_device();
if (!elo || !input_dev) {
err = -ENOMEM;
goto fail1;
}
elo->serio = serio;
elo->id = serio->id.id;
elo->dev = input_dev;
elo->expected_packet = ELO10_TOUCH_PACKET;
mutex_init(&elo->cmd_mutex);
init_completion(&elo->cmd_done);
snprintf(elo->phys, sizeof(elo->phys), "%s/input0", serio->phys);
input_dev->name = "Elo Serial TouchScreen";
input_dev->phys = elo->phys;
input_dev->id.bustype = BUS_RS232;
input_dev->id.vendor = SERIO_ELO;
input_dev->id.product = elo->id;
input_dev->id.version = 0x0100;
input_dev->dev.parent = &serio->dev;
input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
serio_set_drvdata(serio, elo);
err = serio_open(serio, drv);
if (err)
goto fail2;
switch (elo->id) {
case 0: /* 10-byte protocol */
if (elo_setup_10(elo)) {
err = -EIO;
goto fail3;
}
break;
case 1: /* 6-byte protocol */
input_set_abs_params(input_dev, ABS_PRESSURE, 0, 15, 0, 0);
fallthrough;
case 2: /* 4-byte protocol */
input_set_abs_params(input_dev, ABS_X, 96, 4000, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 96, 4000, 0, 0);
break;
case 3: /* 3-byte protocol */
input_set_abs_params(input_dev, ABS_X, 0, 255, 0, 0);
input_set_abs_params(input_dev, ABS_Y, 0, 255, 0, 0);
break;
}
err = input_register_device(elo->dev);
if (err)
goto fail3;
return 0;
fail3: serio_close(serio);
fail2: serio_set_drvdata(serio, NULL);
fail1: input_free_device(input_dev);
kfree(elo);
return err;
}
/*
* The serio driver structure.
*/
static const struct serio_device_id elo_serio_ids[] = {
{
.type = SERIO_RS232,
.proto = SERIO_ELO,
.id = SERIO_ANY,
.extra = SERIO_ANY,
},
{ 0 }
};
MODULE_DEVICE_TABLE(serio, elo_serio_ids);
static struct serio_driver elo_drv = {
.driver = {
.name = "elo",
},
.description = DRIVER_DESC,
.id_table = elo_serio_ids,
.interrupt = elo_interrupt,
.connect = elo_connect,
.disconnect = elo_disconnect,
};
module_serio_driver(elo_drv);
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