linux-stable/drivers/input/touchscreen/sx8654.c
Dmitry Torokhov 22ffc3e42a Input: sx8654 - fix memory allocation check
We have been testing wrong variable when trying to make sure that input
allocation succeeded.

Reported by Coverity (CID 1295918).

Acked-by: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2015-05-13 10:29:33 -07:00

286 lines
6.9 KiB
C

/*
* Driver for Semtech SX8654 I2C touchscreen controller.
*
* Copyright (c) 2015 Armadeus Systems
* Sébastien Szymanski <sebastien.szymanski@armadeus.com>
*
* Using code from:
* - sx865x.c
* Copyright (c) 2013 U-MoBo Srl
* Pierluigi Passaro <p.passaro@u-mobo.com>
* - sx8650.c
* Copyright (c) 2009 Wayne Roberts
* - tsc2007.c
* Copyright (c) 2008 Kwangwoo Lee
* - ads7846.c
* Copyright (c) 2005 David Brownell
* Copyright (c) 2006 Nokia Corporation
* - corgi_ts.c
* Copyright (C) 2004-2005 Richard Purdie
* - omap_ts.[hc], ads7846.h, ts_osk.c
* Copyright (C) 2002 MontaVista Software
* Copyright (C) 2004 Texas Instruments
* Copyright (C) 2005 Dirk Behme
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/input.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
/* register addresses */
#define I2C_REG_TOUCH0 0x00
#define I2C_REG_TOUCH1 0x01
#define I2C_REG_CHANMASK 0x04
#define I2C_REG_IRQMASK 0x22
#define I2C_REG_IRQSRC 0x23
#define I2C_REG_SOFTRESET 0x3f
/* commands */
#define CMD_READ_REGISTER 0x40
#define CMD_MANUAL 0xc0
#define CMD_PENTRG 0xe0
/* value for I2C_REG_SOFTRESET */
#define SOFTRESET_VALUE 0xde
/* bits for I2C_REG_IRQSRC */
#define IRQ_PENTOUCH_TOUCHCONVDONE 0x08
#define IRQ_PENRELEASE 0x04
/* bits for RegTouch1 */
#define CONDIRQ 0x20
#define FILT_7SA 0x03
/* bits for I2C_REG_CHANMASK */
#define CONV_X 0x80
#define CONV_Y 0x40
/* coordinates rate: higher nibble of CTRL0 register */
#define RATE_MANUAL 0x00
#define RATE_5000CPS 0xf0
/* power delay: lower nibble of CTRL0 register */
#define POWDLY_1_1MS 0x0b
#define MAX_12BIT ((1 << 12) - 1)
struct sx8654 {
struct input_dev *input;
struct i2c_client *client;
};
static irqreturn_t sx8654_irq(int irq, void *handle)
{
struct sx8654 *sx8654 = handle;
int irqsrc;
u8 data[4];
unsigned int x, y;
int retval;
irqsrc = i2c_smbus_read_byte_data(sx8654->client,
CMD_READ_REGISTER | I2C_REG_IRQSRC);
dev_dbg(&sx8654->client->dev, "irqsrc = 0x%x", irqsrc);
if (irqsrc < 0)
goto out;
if (irqsrc & IRQ_PENRELEASE) {
dev_dbg(&sx8654->client->dev, "pen release interrupt");
input_report_key(sx8654->input, BTN_TOUCH, 0);
input_sync(sx8654->input);
}
if (irqsrc & IRQ_PENTOUCH_TOUCHCONVDONE) {
dev_dbg(&sx8654->client->dev, "pen touch interrupt");
retval = i2c_master_recv(sx8654->client, data, sizeof(data));
if (retval != sizeof(data))
goto out;
/* invalid data */
if (unlikely(data[0] & 0x80 || data[2] & 0x80))
goto out;
x = ((data[0] & 0xf) << 8) | (data[1]);
y = ((data[2] & 0xf) << 8) | (data[3]);
input_report_abs(sx8654->input, ABS_X, x);
input_report_abs(sx8654->input, ABS_Y, y);
input_report_key(sx8654->input, BTN_TOUCH, 1);
input_sync(sx8654->input);
dev_dbg(&sx8654->client->dev, "point(%4d,%4d)\n", x, y);
}
out:
return IRQ_HANDLED;
}
static int sx8654_open(struct input_dev *dev)
{
struct sx8654 *sx8654 = input_get_drvdata(dev);
struct i2c_client *client = sx8654->client;
int error;
/* enable pen trigger mode */
error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0,
RATE_5000CPS | POWDLY_1_1MS);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
return error;
}
error = i2c_smbus_write_byte(client, CMD_PENTRG);
if (error) {
dev_err(&client->dev, "writing command CMD_PENTRG failed");
return error;
}
enable_irq(client->irq);
return 0;
}
static void sx8654_close(struct input_dev *dev)
{
struct sx8654 *sx8654 = input_get_drvdata(dev);
struct i2c_client *client = sx8654->client;
int error;
disable_irq(client->irq);
/* enable manual mode mode */
error = i2c_smbus_write_byte(client, CMD_MANUAL);
if (error) {
dev_err(&client->dev, "writing command CMD_MANUAL failed");
return;
}
error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH0, 0);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_TOUCH0 failed");
return;
}
}
static int sx8654_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct sx8654 *sx8654;
struct input_dev *input;
int error;
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_WORD_DATA))
return -ENXIO;
sx8654 = devm_kzalloc(&client->dev, sizeof(*sx8654), GFP_KERNEL);
if (!sx8654)
return -ENOMEM;
input = devm_input_allocate_device(&client->dev);
if (!input)
return -ENOMEM;
input->name = "SX8654 I2C Touchscreen";
input->id.bustype = BUS_I2C;
input->dev.parent = &client->dev;
input->open = sx8654_open;
input->close = sx8654_close;
__set_bit(INPUT_PROP_DIRECT, input->propbit);
input_set_capability(input, EV_KEY, BTN_TOUCH);
input_set_abs_params(input, ABS_X, 0, MAX_12BIT, 0, 0);
input_set_abs_params(input, ABS_Y, 0, MAX_12BIT, 0, 0);
sx8654->client = client;
sx8654->input = input;
input_set_drvdata(sx8654->input, sx8654);
error = i2c_smbus_write_byte_data(client, I2C_REG_SOFTRESET,
SOFTRESET_VALUE);
if (error) {
dev_err(&client->dev, "writing softreset value failed");
return error;
}
error = i2c_smbus_write_byte_data(client, I2C_REG_CHANMASK,
CONV_X | CONV_Y);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_CHANMASK failed");
return error;
}
error = i2c_smbus_write_byte_data(client, I2C_REG_IRQMASK,
IRQ_PENTOUCH_TOUCHCONVDONE |
IRQ_PENRELEASE);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_IRQMASK failed");
return error;
}
error = i2c_smbus_write_byte_data(client, I2C_REG_TOUCH1,
CONDIRQ | FILT_7SA);
if (error) {
dev_err(&client->dev, "writing to I2C_REG_TOUCH1 failed");
return error;
}
error = devm_request_threaded_irq(&client->dev, client->irq,
NULL, sx8654_irq,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
client->name, sx8654);
if (error) {
dev_err(&client->dev,
"Failed to enable IRQ %d, error: %d\n",
client->irq, error);
return error;
}
/* Disable the IRQ, we'll enable it in sx8654_open() */
disable_irq(client->irq);
error = input_register_device(sx8654->input);
if (error)
return error;
i2c_set_clientdata(client, sx8654);
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id sx8654_of_match[] = {
{ .compatible = "semtech,sx8654", },
{ },
};
MODULE_DEVICE_TABLE(of, sx8654_of_match);
#endif
static const struct i2c_device_id sx8654_id_table[] = {
{ "semtech_sx8654", 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, sx8654_id_table);
static struct i2c_driver sx8654_driver = {
.driver = {
.name = "sx8654",
.of_match_table = of_match_ptr(sx8654_of_match),
},
.id_table = sx8654_id_table,
.probe = sx8654_probe,
};
module_i2c_driver(sx8654_driver);
MODULE_AUTHOR("Sébastien Szymanski <sebastien.szymanski@armadeus.com>");
MODULE_DESCRIPTION("Semtech SX8654 I2C Touchscreen Driver");
MODULE_LICENSE("GPL");