![Hans Verkuil](/assets/img/avatar_default.png)
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>
153 lines
5 KiB
C
153 lines
5 KiB
C
/*
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* v4l2-i2c-drv-legacy.h - contains I2C handling code that's identical
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* for all V4L2 I2C drivers. Use this header if the
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* I2C driver is used by both legacy drivers and
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* drivers converted to the bus-based I2C API.
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*
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* Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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/* NOTE: the full version of this header is in the v4l-dvb repository
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* and allows v4l i2c drivers to be compiled on older kernels as well.
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* The version of this header as it appears in the kernel is a stripped
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* version (without all the backwards compatibility stuff) and so it
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* looks a bit odd.
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*
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* If you look at the full version then you will understand the reason
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* for introducing this header since you really don't want to have all
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* the tricky backwards compatibility code in each and every i2c driver.
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*/
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struct v4l2_i2c_driver_data {
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const char * const name;
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int driverid;
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int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
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int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
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int (*remove)(struct i2c_client *client);
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int (*suspend)(struct i2c_client *client, pm_message_t state);
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int (*resume)(struct i2c_client *client);
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int (*legacy_probe)(struct i2c_adapter *adapter);
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int legacy_class;
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const struct i2c_device_id *id_table;
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};
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static struct v4l2_i2c_driver_data v4l2_i2c_data;
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static const struct i2c_client_address_data addr_data;
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static struct i2c_driver v4l2_i2c_driver_legacy;
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static char v4l2_i2c_drv_name_legacy[32];
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static int v4l2_i2c_drv_attach_legacy(struct i2c_adapter *adapter, int address, int kind)
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{
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return v4l2_i2c_attach(adapter, address, &v4l2_i2c_driver_legacy,
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v4l2_i2c_drv_name_legacy, v4l2_i2c_data.probe);
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}
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static int v4l2_i2c_drv_probe_legacy(struct i2c_adapter *adapter)
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{
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if (v4l2_i2c_data.legacy_probe) {
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if (v4l2_i2c_data.legacy_probe(adapter))
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return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
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return 0;
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}
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if (adapter->class & v4l2_i2c_data.legacy_class)
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return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
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return 0;
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}
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static int v4l2_i2c_drv_detach_legacy(struct i2c_client *client)
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{
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int err;
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if (v4l2_i2c_data.remove)
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v4l2_i2c_data.remove(client);
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err = i2c_detach_client(client);
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if (err)
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return err;
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kfree(client);
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return 0;
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}
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static int v4l2_i2c_drv_suspend_helper(struct i2c_client *client, pm_message_t state)
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{
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return v4l2_i2c_data.suspend ? v4l2_i2c_data.suspend(client, state) : 0;
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}
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static int v4l2_i2c_drv_resume_helper(struct i2c_client *client)
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{
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return v4l2_i2c_data.resume ? v4l2_i2c_data.resume(client) : 0;
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}
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/* ----------------------------------------------------------------------- */
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/* i2c implementation */
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static struct i2c_driver v4l2_i2c_driver_legacy = {
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.driver = {
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.owner = THIS_MODULE,
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},
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.attach_adapter = v4l2_i2c_drv_probe_legacy,
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.detach_client = v4l2_i2c_drv_detach_legacy,
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.suspend = v4l2_i2c_drv_suspend_helper,
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.resume = v4l2_i2c_drv_resume_helper,
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};
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/* ----------------------------------------------------------------------- */
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/* i2c implementation */
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static struct i2c_driver v4l2_i2c_driver = {
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.suspend = v4l2_i2c_drv_suspend_helper,
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.resume = v4l2_i2c_drv_resume_helper,
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};
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static int __init v4l2_i2c_drv_init(void)
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{
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int err;
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strlcpy(v4l2_i2c_drv_name_legacy, v4l2_i2c_data.name, sizeof(v4l2_i2c_drv_name_legacy));
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strlcat(v4l2_i2c_drv_name_legacy, "'", sizeof(v4l2_i2c_drv_name_legacy));
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if (v4l2_i2c_data.legacy_class == 0)
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v4l2_i2c_data.legacy_class = I2C_CLASS_TV_ANALOG;
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v4l2_i2c_driver_legacy.driver.name = v4l2_i2c_drv_name_legacy;
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v4l2_i2c_driver_legacy.id = v4l2_i2c_data.driverid;
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v4l2_i2c_driver_legacy.command = v4l2_i2c_data.command;
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err = i2c_add_driver(&v4l2_i2c_driver_legacy);
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if (err)
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return err;
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v4l2_i2c_driver.driver.name = v4l2_i2c_data.name;
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v4l2_i2c_driver.id = v4l2_i2c_data.driverid;
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v4l2_i2c_driver.command = v4l2_i2c_data.command;
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v4l2_i2c_driver.probe = v4l2_i2c_data.probe;
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v4l2_i2c_driver.remove = v4l2_i2c_data.remove;
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v4l2_i2c_driver.id_table = v4l2_i2c_data.id_table;
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err = i2c_add_driver(&v4l2_i2c_driver);
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if (err)
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i2c_del_driver(&v4l2_i2c_driver_legacy);
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return err;
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}
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static void __exit v4l2_i2c_drv_cleanup(void)
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{
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i2c_del_driver(&v4l2_i2c_driver_legacy);
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i2c_del_driver(&v4l2_i2c_driver);
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}
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module_init(v4l2_i2c_drv_init);
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module_exit(v4l2_i2c_drv_cleanup);
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