linux/drivers/hwmon/lis3lv02d_i2c.c
Kuninori Morimoto 5facb09713 hwmon: (lis3lv02d) Prevent NULL pointer dereference
If CONFIG_PM was selected and lis3lv02d_platform_data was NULL,
the kernel will be panic when halt command run.

Reported-by: Yusuke Goda <yusuke.goda.sx@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Sigend-off-by: Jean Delvare <khali@linux-fr.org>
2010-09-17 17:24:10 +02:00

184 lines
4.5 KiB
C

/*
* drivers/hwmon/lis3lv02d_i2c.c
*
* Implements I2C interface for lis3lv02d (STMicroelectronics) accelerometer.
* Driver is based on corresponding SPI driver written by Daniel Mack
* (lis3lv02d_spi.c (C) 2009 Daniel Mack <daniel@caiaq.de> ).
*
* Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
*
* Contact: Samu Onkalo <samu.p.onkalo@nokia.com>
*
* 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.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include "lis3lv02d.h"
#define DRV_NAME "lis3lv02d_i2c"
static inline s32 lis3_i2c_write(struct lis3lv02d *lis3, int reg, u8 value)
{
struct i2c_client *c = lis3->bus_priv;
return i2c_smbus_write_byte_data(c, reg, value);
}
static inline s32 lis3_i2c_read(struct lis3lv02d *lis3, int reg, u8 *v)
{
struct i2c_client *c = lis3->bus_priv;
*v = i2c_smbus_read_byte_data(c, reg);
return 0;
}
static int lis3_i2c_init(struct lis3lv02d *lis3)
{
u8 reg;
int ret;
/* power up the device */
ret = lis3->read(lis3, CTRL_REG1, &reg);
if (ret < 0)
return ret;
reg |= CTRL1_PD0;
return lis3->write(lis3, CTRL_REG1, reg);
}
/* Default axis mapping but it can be overwritten by platform data */
static struct axis_conversion lis3lv02d_axis_map = { LIS3_DEV_X,
LIS3_DEV_Y,
LIS3_DEV_Z };
static int __devinit lis3lv02d_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret = 0;
struct lis3lv02d_platform_data *pdata = client->dev.platform_data;
if (pdata) {
if (pdata->axis_x)
lis3lv02d_axis_map.x = pdata->axis_x;
if (pdata->axis_y)
lis3lv02d_axis_map.y = pdata->axis_y;
if (pdata->axis_z)
lis3lv02d_axis_map.z = pdata->axis_z;
if (pdata->setup_resources)
ret = pdata->setup_resources();
if (ret)
goto fail;
}
lis3_dev.pdata = pdata;
lis3_dev.bus_priv = client;
lis3_dev.init = lis3_i2c_init;
lis3_dev.read = lis3_i2c_read;
lis3_dev.write = lis3_i2c_write;
lis3_dev.irq = client->irq;
lis3_dev.ac = lis3lv02d_axis_map;
i2c_set_clientdata(client, &lis3_dev);
ret = lis3lv02d_init_device(&lis3_dev);
fail:
return ret;
}
static int __devexit lis3lv02d_i2c_remove(struct i2c_client *client)
{
struct lis3lv02d *lis3 = i2c_get_clientdata(client);
struct lis3lv02d_platform_data *pdata = client->dev.platform_data;
if (pdata && pdata->release_resources)
pdata->release_resources();
lis3lv02d_joystick_disable();
lis3lv02d_poweroff(lis3);
return lis3lv02d_remove_fs(&lis3_dev);
}
#ifdef CONFIG_PM
static int lis3lv02d_i2c_suspend(struct i2c_client *client, pm_message_t mesg)
{
struct lis3lv02d *lis3 = i2c_get_clientdata(client);
if (!lis3->pdata || !lis3->pdata->wakeup_flags)
lis3lv02d_poweroff(lis3);
return 0;
}
static int lis3lv02d_i2c_resume(struct i2c_client *client)
{
struct lis3lv02d *lis3 = i2c_get_clientdata(client);
if (!lis3->pdata || !lis3->pdata->wakeup_flags)
lis3lv02d_poweron(lis3);
return 0;
}
static void lis3lv02d_i2c_shutdown(struct i2c_client *client)
{
lis3lv02d_i2c_suspend(client, PMSG_SUSPEND);
}
#else
#define lis3lv02d_i2c_suspend NULL
#define lis3lv02d_i2c_resume NULL
#define lis3lv02d_i2c_shutdown NULL
#endif
static const struct i2c_device_id lis3lv02d_id[] = {
{"lis3lv02d", 0 },
{}
};
MODULE_DEVICE_TABLE(i2c, lis3lv02d_id);
static struct i2c_driver lis3lv02d_i2c_driver = {
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
},
.suspend = lis3lv02d_i2c_suspend,
.shutdown = lis3lv02d_i2c_shutdown,
.resume = lis3lv02d_i2c_resume,
.probe = lis3lv02d_i2c_probe,
.remove = __devexit_p(lis3lv02d_i2c_remove),
.id_table = lis3lv02d_id,
};
static int __init lis3lv02d_init(void)
{
return i2c_add_driver(&lis3lv02d_i2c_driver);
}
static void __exit lis3lv02d_exit(void)
{
i2c_del_driver(&lis3lv02d_i2c_driver);
}
MODULE_AUTHOR("Nokia Corporation");
MODULE_DESCRIPTION("lis3lv02d I2C interface");
MODULE_LICENSE("GPL");
module_init(lis3lv02d_init);
module_exit(lis3lv02d_exit);