linux/drivers/media/radio/tef6862.c
Herton Ronaldo Krzesinski 80845a3316 [media] v4l: make sure drivers supply a zeroed struct v4l2_subdev
Some v4l drivers currently don't initialize their struct v4l2_subdev
with zeros, and this is a problem since some of the v4l2 code expects
this. One example is the addition of internal_ops in commit 45f6f84,
after that we are at risk of random oopses with these drivers when code
in v4l2_device_register_subdev tries to dereference sd->internal_ops->*,
as can be shown by the report at http://bugs.launchpad.net/bugs/745213
and analysis of its crash at https://lkml.org/lkml/2011/4/1/168

Use kzalloc within problematic drivers to ensure we have a zeroed struct
v4l2_subdev.

BugLink: http://bugs.launchpad.net/bugs/745213
Cc: <stable@kernel.org>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2011-04-29 12:33:28 -03:00

232 lines
5.6 KiB
C

/*
* tef6862.c Philips TEF6862 Car Radio Enhanced Selectivity Tuner
* Copyright (c) 2009 Intel Corporation
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-device.h>
#include <media/v4l2-chip-ident.h>
#define DRIVER_NAME "tef6862"
#define FREQ_MUL 16000
#define TEF6862_LO_FREQ (875 * FREQ_MUL / 10)
#define TEF6862_HI_FREQ (108 * FREQ_MUL)
/* Write mode sub addresses */
#define WM_SUB_BANDWIDTH 0x0
#define WM_SUB_PLLM 0x1
#define WM_SUB_PLLL 0x2
#define WM_SUB_DAA 0x3
#define WM_SUB_AGC 0x4
#define WM_SUB_BAND 0x5
#define WM_SUB_CONTROL 0x6
#define WM_SUB_LEVEL 0x7
#define WM_SUB_IFCF 0x8
#define WM_SUB_IFCAP 0x9
#define WM_SUB_ACD 0xA
#define WM_SUB_TEST 0xF
/* Different modes of the MSA register */
#define MODE_BUFFER 0x0
#define MODE_PRESET 0x1
#define MODE_SEARCH 0x2
#define MODE_AF_UPDATE 0x3
#define MODE_JUMP 0x4
#define MODE_CHECK 0x5
#define MODE_LOAD 0x6
#define MODE_END 0x7
#define MODE_SHIFT 5
struct tef6862_state {
struct v4l2_subdev sd;
unsigned long freq;
};
static inline struct tef6862_state *to_state(struct v4l2_subdev *sd)
{
return container_of(sd, struct tef6862_state, sd);
}
static u16 tef6862_sigstr(struct i2c_client *client)
{
u8 buf[4];
int err = i2c_master_recv(client, buf, sizeof(buf));
if (err == sizeof(buf))
return buf[3] << 8;
return 0;
}
static int tef6862_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
{
if (v->index > 0)
return -EINVAL;
/* only support FM for now */
strlcpy(v->name, "FM", sizeof(v->name));
v->type = V4L2_TUNER_RADIO;
v->rangelow = TEF6862_LO_FREQ;
v->rangehigh = TEF6862_HI_FREQ;
v->rxsubchans = V4L2_TUNER_SUB_MONO;
v->capability = V4L2_TUNER_CAP_LOW;
v->audmode = V4L2_TUNER_MODE_STEREO;
v->signal = tef6862_sigstr(v4l2_get_subdevdata(sd));
return 0;
}
static int tef6862_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *v)
{
return v->index ? -EINVAL : 0;
}
static int tef6862_s_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
{
struct tef6862_state *state = to_state(sd);
struct i2c_client *client = v4l2_get_subdevdata(sd);
u16 pll;
u8 i2cmsg[3];
int err;
if (f->tuner != 0)
return -EINVAL;
pll = 1964 + ((f->frequency - TEF6862_LO_FREQ) * 20) / FREQ_MUL;
i2cmsg[0] = (MODE_PRESET << MODE_SHIFT) | WM_SUB_PLLM;
i2cmsg[1] = (pll >> 8) & 0xff;
i2cmsg[2] = pll & 0xff;
err = i2c_master_send(client, i2cmsg, sizeof(i2cmsg));
if (!err)
state->freq = f->frequency;
return err;
}
static int tef6862_g_frequency(struct v4l2_subdev *sd, struct v4l2_frequency *f)
{
struct tef6862_state *state = to_state(sd);
if (f->tuner != 0)
return -EINVAL;
f->type = V4L2_TUNER_RADIO;
f->frequency = state->freq;
return 0;
}
static int tef6862_g_chip_ident(struct v4l2_subdev *sd,
struct v4l2_dbg_chip_ident *chip)
{
struct i2c_client *client = v4l2_get_subdevdata(sd);
return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TEF6862, 0);
}
static const struct v4l2_subdev_tuner_ops tef6862_tuner_ops = {
.g_tuner = tef6862_g_tuner,
.s_tuner = tef6862_s_tuner,
.s_frequency = tef6862_s_frequency,
.g_frequency = tef6862_g_frequency,
};
static const struct v4l2_subdev_core_ops tef6862_core_ops = {
.g_chip_ident = tef6862_g_chip_ident,
};
static const struct v4l2_subdev_ops tef6862_ops = {
.core = &tef6862_core_ops,
.tuner = &tef6862_tuner_ops,
};
/*
* Generic i2c probe
* concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
*/
static int __devinit tef6862_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct tef6862_state *state;
struct v4l2_subdev *sd;
/* Check if the adapter supports the needed features */
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
return -EIO;
v4l_info(client, "chip found @ 0x%02x (%s)\n",
client->addr << 1, client->adapter->name);
state = kzalloc(sizeof(struct tef6862_state), GFP_KERNEL);
if (state == NULL)
return -ENOMEM;
state->freq = TEF6862_LO_FREQ;
sd = &state->sd;
v4l2_i2c_subdev_init(sd, client, &tef6862_ops);
return 0;
}
static int __devexit tef6862_remove(struct i2c_client *client)
{
struct v4l2_subdev *sd = i2c_get_clientdata(client);
v4l2_device_unregister_subdev(sd);
kfree(to_state(sd));
return 0;
}
static const struct i2c_device_id tef6862_id[] = {
{DRIVER_NAME, 0},
{},
};
MODULE_DEVICE_TABLE(i2c, tef6862_id);
static struct i2c_driver tef6862_driver = {
.driver = {
.owner = THIS_MODULE,
.name = DRIVER_NAME,
},
.probe = tef6862_probe,
.remove = tef6862_remove,
.id_table = tef6862_id,
};
static __init int tef6862_init(void)
{
return i2c_add_driver(&tef6862_driver);
}
static __exit void tef6862_exit(void)
{
i2c_del_driver(&tef6862_driver);
}
module_init(tef6862_init);
module_exit(tef6862_exit);
MODULE_DESCRIPTION("TEF6862 Car Radio Enhanced Selectivity Tuner");
MODULE_AUTHOR("Mocean Laboratories");
MODULE_LICENSE("GPL v2");