linux-stable/include/media/v4l2-i2c-drv-legacy.h
Hans Verkuil 7b31b57a37 V4L/DVB (9209): v4l2: add comment to the v4l2-i2c-drv headers.
Looking at these headers as they appear in the kernel makes you
wonder why it is done that way. Refer to the v4l-dvb repository
where the full unstripped header can be found to understand the
reasoning behind this.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-17 17:20:20 -03:00

152 lines
5 KiB
C

/*
* v4l2-i2c-drv-legacy.h - contains I2C handling code that's identical
* for all V4L2 I2C drivers. Use this header if the
* I2C driver is used by both legacy drivers and
* drivers converted to the bus-based I2C API.
*
* Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*/
/* NOTE: the full version of this header is in the v4l-dvb repository
* and allows v4l i2c drivers to be compiled on older kernels as well.
* The version of this header as it appears in the kernel is a stripped
* version (without all the backwards compatibility stuff) and so it
* looks a bit odd.
*
* If you look at the full version then you will understand the reason
* for introducing this header since you really don't want to have all
* the tricky backwards compatibility code in each and every i2c driver.
*/
struct v4l2_i2c_driver_data {
const char * const name;
int driverid;
int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
int (*remove)(struct i2c_client *client);
int (*suspend)(struct i2c_client *client, pm_message_t state);
int (*resume)(struct i2c_client *client);
int (*legacy_probe)(struct i2c_adapter *adapter);
int legacy_class;
const struct i2c_device_id *id_table;
};
static struct v4l2_i2c_driver_data v4l2_i2c_data;
static const struct i2c_client_address_data addr_data;
static struct i2c_driver v4l2_i2c_driver_legacy;
static char v4l2_i2c_drv_name_legacy[32];
static int v4l2_i2c_drv_attach_legacy(struct i2c_adapter *adapter, int address, int kind)
{
return v4l2_i2c_attach(adapter, address, &v4l2_i2c_driver_legacy,
v4l2_i2c_drv_name_legacy, v4l2_i2c_data.probe);
}
static int v4l2_i2c_drv_probe_legacy(struct i2c_adapter *adapter)
{
if (v4l2_i2c_data.legacy_probe) {
if (v4l2_i2c_data.legacy_probe(adapter))
return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
return 0;
}
if (adapter->class & v4l2_i2c_data.legacy_class)
return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
return 0;
}
static int v4l2_i2c_drv_detach_legacy(struct i2c_client *client)
{
int err;
if (v4l2_i2c_data.remove)
v4l2_i2c_data.remove(client);
err = i2c_detach_client(client);
if (err)
return err;
kfree(client);
return 0;
}
static int v4l2_i2c_drv_suspend_helper(struct i2c_client *client, pm_message_t state)
{
return v4l2_i2c_data.suspend ? v4l2_i2c_data.suspend(client, state) : 0;
}
static int v4l2_i2c_drv_resume_helper(struct i2c_client *client)
{
return v4l2_i2c_data.resume ? v4l2_i2c_data.resume(client) : 0;
}
/* ----------------------------------------------------------------------- */
/* i2c implementation */
static struct i2c_driver v4l2_i2c_driver_legacy = {
.driver = {
.owner = THIS_MODULE,
},
.attach_adapter = v4l2_i2c_drv_probe_legacy,
.detach_client = v4l2_i2c_drv_detach_legacy,
.suspend = v4l2_i2c_drv_suspend_helper,
.resume = v4l2_i2c_drv_resume_helper,
};
/* ----------------------------------------------------------------------- */
/* i2c implementation */
static struct i2c_driver v4l2_i2c_driver = {
.suspend = v4l2_i2c_drv_suspend_helper,
.resume = v4l2_i2c_drv_resume_helper,
};
static int __init v4l2_i2c_drv_init(void)
{
int err;
strlcpy(v4l2_i2c_drv_name_legacy, v4l2_i2c_data.name, sizeof(v4l2_i2c_drv_name_legacy));
strlcat(v4l2_i2c_drv_name_legacy, "'", sizeof(v4l2_i2c_drv_name_legacy));
if (v4l2_i2c_data.legacy_class == 0)
v4l2_i2c_data.legacy_class = I2C_CLASS_TV_ANALOG;
v4l2_i2c_driver_legacy.driver.name = v4l2_i2c_drv_name_legacy;
v4l2_i2c_driver_legacy.id = v4l2_i2c_data.driverid;
v4l2_i2c_driver_legacy.command = v4l2_i2c_data.command;
err = i2c_add_driver(&v4l2_i2c_driver_legacy);
if (err)
return err;
v4l2_i2c_driver.driver.name = v4l2_i2c_data.name;
v4l2_i2c_driver.id = v4l2_i2c_data.driverid;
v4l2_i2c_driver.command = v4l2_i2c_data.command;
v4l2_i2c_driver.probe = v4l2_i2c_data.probe;
v4l2_i2c_driver.remove = v4l2_i2c_data.remove;
v4l2_i2c_driver.id_table = v4l2_i2c_data.id_table;
err = i2c_add_driver(&v4l2_i2c_driver);
if (err)
i2c_del_driver(&v4l2_i2c_driver_legacy);
return err;
}
static void __exit v4l2_i2c_drv_cleanup(void)
{
i2c_del_driver(&v4l2_i2c_driver_legacy);
i2c_del_driver(&v4l2_i2c_driver);
}
module_init(v4l2_i2c_drv_init);
module_exit(v4l2_i2c_drv_cleanup);