tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * v4l2-i2c-drv-legacy.h - contains I2C handling code that's identical
3 * for all V4L2 I2C drivers. Use this header if the
4 * I2C driver is used by both legacy drivers and
5 * drivers converted to the bus-based I2C API.
6 *
7 * Copyright (C) 2007 Hans Verkuil <hverkuil@xs4all.nl>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24/* NOTE: the full version of this header is in the v4l-dvb repository
25 * and allows v4l i2c drivers to be compiled on older kernels as well.
26 * The version of this header as it appears in the kernel is a stripped
27 * version (without all the backwards compatibility stuff) and so it
28 * looks a bit odd.
29 *
30 * If you look at the full version then you will understand the reason
31 * for introducing this header since you really don't want to have all
32 * the tricky backwards compatibility code in each and every i2c driver.
33 */
34
35struct v4l2_i2c_driver_data {
36 const char * const name;
37 int driverid;
38 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
39 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
40 int (*remove)(struct i2c_client *client);
41 int (*suspend)(struct i2c_client *client, pm_message_t state);
42 int (*resume)(struct i2c_client *client);
43 int (*legacy_probe)(struct i2c_adapter *adapter);
44 int legacy_class;
45 const struct i2c_device_id *id_table;
46};
47
48static struct v4l2_i2c_driver_data v4l2_i2c_data;
49static const struct i2c_client_address_data addr_data;
50static struct i2c_driver v4l2_i2c_driver_legacy;
51static char v4l2_i2c_drv_name_legacy[32];
52
53static int v4l2_i2c_drv_attach_legacy(struct i2c_adapter *adapter, int address, int kind)
54{
55 return v4l2_i2c_attach(adapter, address, &v4l2_i2c_driver_legacy,
56 v4l2_i2c_drv_name_legacy, v4l2_i2c_data.probe);
57}
58
59static int v4l2_i2c_drv_probe_legacy(struct i2c_adapter *adapter)
60{
61 if (v4l2_i2c_data.legacy_probe) {
62 if (v4l2_i2c_data.legacy_probe(adapter))
63 return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
64 return 0;
65 }
66 if (adapter->class & v4l2_i2c_data.legacy_class)
67 return i2c_probe(adapter, &addr_data, v4l2_i2c_drv_attach_legacy);
68 return 0;
69}
70
71static int v4l2_i2c_drv_detach_legacy(struct i2c_client *client)
72{
73 int err;
74
75 if (v4l2_i2c_data.remove)
76 v4l2_i2c_data.remove(client);
77
78 err = i2c_detach_client(client);
79 if (err)
80 return err;
81 kfree(client);
82 return 0;
83}
84
85static int v4l2_i2c_drv_suspend_helper(struct i2c_client *client, pm_message_t state)
86{
87 return v4l2_i2c_data.suspend ? v4l2_i2c_data.suspend(client, state) : 0;
88}
89
90static int v4l2_i2c_drv_resume_helper(struct i2c_client *client)
91{
92 return v4l2_i2c_data.resume ? v4l2_i2c_data.resume(client) : 0;
93}
94
95/* ----------------------------------------------------------------------- */
96
97/* i2c implementation */
98static struct i2c_driver v4l2_i2c_driver_legacy = {
99 .driver = {
100 .owner = THIS_MODULE,
101 },
102 .attach_adapter = v4l2_i2c_drv_probe_legacy,
103 .detach_client = v4l2_i2c_drv_detach_legacy,
104 .suspend = v4l2_i2c_drv_suspend_helper,
105 .resume = v4l2_i2c_drv_resume_helper,
106};
107
108/* ----------------------------------------------------------------------- */
109
110/* i2c implementation */
111static struct i2c_driver v4l2_i2c_driver = {
112 .suspend = v4l2_i2c_drv_suspend_helper,
113 .resume = v4l2_i2c_drv_resume_helper,
114};
115
116static int __init v4l2_i2c_drv_init(void)
117{
118 int err;
119
120 strlcpy(v4l2_i2c_drv_name_legacy, v4l2_i2c_data.name, sizeof(v4l2_i2c_drv_name_legacy));
121 strlcat(v4l2_i2c_drv_name_legacy, "'", sizeof(v4l2_i2c_drv_name_legacy));
122
123 if (v4l2_i2c_data.legacy_class == 0)
124 v4l2_i2c_data.legacy_class = I2C_CLASS_TV_ANALOG;
125
126 v4l2_i2c_driver_legacy.driver.name = v4l2_i2c_drv_name_legacy;
127 v4l2_i2c_driver_legacy.id = v4l2_i2c_data.driverid;
128 v4l2_i2c_driver_legacy.command = v4l2_i2c_data.command;
129 err = i2c_add_driver(&v4l2_i2c_driver_legacy);
130
131 if (err)
132 return err;
133 v4l2_i2c_driver.driver.name = v4l2_i2c_data.name;
134 v4l2_i2c_driver.id = v4l2_i2c_data.driverid;
135 v4l2_i2c_driver.command = v4l2_i2c_data.command;
136 v4l2_i2c_driver.probe = v4l2_i2c_data.probe;
137 v4l2_i2c_driver.remove = v4l2_i2c_data.remove;
138 v4l2_i2c_driver.id_table = v4l2_i2c_data.id_table;
139 err = i2c_add_driver(&v4l2_i2c_driver);
140 if (err)
141 i2c_del_driver(&v4l2_i2c_driver_legacy);
142 return err;
143}
144
145static void __exit v4l2_i2c_drv_cleanup(void)
146{
147 i2c_del_driver(&v4l2_i2c_driver_legacy);
148 i2c_del_driver(&v4l2_i2c_driver);
149}
150
151module_init(v4l2_i2c_drv_init);
152module_exit(v4l2_i2c_drv_cleanup);