Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
tda9840.c
Go to the documentation of this file.
1  /*
2  tda9840 - i2c-driver for the tda9840 by SGS Thomson
3 
4  Copyright (C) 1998-2003 Michael Hunold <[email protected]>
5  Copyright (C) 2008 Hans Verkuil <[email protected]>
6 
7  The tda9840 is a stereo/dual sound processor with digital
8  identification. It can be found at address 0x84 on the i2c-bus.
9 
10  For detailed informations download the specifications directly
11  from SGS Thomson at http://www.st.com
12 
13  This program is free software; you can redistribute it and/or modify
14  it under the terms of the GNU General Public License as published by
15  the Free Software Foundation; either version 2 of the License, or
16  (at your option) any later version.
17 
18  This program is distributed in the hope that it will be useful,
19  but WITHOUT ANY WARRANTY; without even the implied warranty of
20  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21  GNU General Public License for more details.
22 
23  You should have received a copy of the GNU General Public License
24  along with this program; if not, write to the Free Software
25  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26  */
27 
28 
29 #include <linux/module.h>
30 #include <linux/ioctl.h>
31 #include <linux/slab.h>
32 #include <linux/i2c.h>
33 #include <media/v4l2-device.h>
34 #include <media/v4l2-chip-ident.h>
35 
36 MODULE_AUTHOR("Michael Hunold <[email protected]>");
37 MODULE_DESCRIPTION("tda9840 driver");
38 MODULE_LICENSE("GPL");
39 
40 static int debug;
41 module_param(debug, int, 0644);
42 
43 MODULE_PARM_DESC(debug, "Debug level (0-1)");
44 
45 #define SWITCH 0x00
46 #define LEVEL_ADJUST 0x02
47 #define STEREO_ADJUST 0x03
48 #define TEST 0x04
49 
50 #define TDA9840_SET_MUTE 0x00
51 #define TDA9840_SET_MONO 0x10
52 #define TDA9840_SET_STEREO 0x2a
53 #define TDA9840_SET_LANG1 0x12
54 #define TDA9840_SET_LANG2 0x1e
55 #define TDA9840_SET_BOTH 0x1a
56 #define TDA9840_SET_BOTH_R 0x16
57 #define TDA9840_SET_EXTERNAL 0x7a
58 
59 
60 static void tda9840_write(struct v4l2_subdev *sd, u8 reg, u8 val)
61 {
62  struct i2c_client *client = v4l2_get_subdevdata(sd);
63 
64  if (i2c_smbus_write_byte_data(client, reg, val))
65  v4l2_dbg(1, debug, sd, "error writing %02x to %02x\n",
66  val, reg);
67 }
68 
69 static int tda9840_status(struct v4l2_subdev *sd)
70 {
71  struct i2c_client *client = v4l2_get_subdevdata(sd);
72  u8 byte;
73 
74  if (1 != i2c_master_recv(client, &byte, 1)) {
75  v4l2_dbg(1, debug, sd,
76  "i2c_master_recv() failed\n");
77  return -EIO;
78  }
79 
80  if (byte & 0x80) {
81  v4l2_dbg(1, debug, sd,
82  "TDA9840_DETECT: register contents invalid\n");
83  return -EINVAL;
84  }
85 
86  v4l2_dbg(1, debug, sd, "TDA9840_DETECT: byte: 0x%02x\n", byte);
87  return byte & 0x60;
88 }
89 
90 static int tda9840_s_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *t)
91 {
92  int stat = tda9840_status(sd);
93  int byte;
94 
95  if (t->index)
96  return -EINVAL;
97 
98  stat = stat < 0 ? 0 : stat;
99  if (stat == 0 || stat == 0x60) /* mono input */
100  byte = TDA9840_SET_MONO;
101  else if (stat == 0x40) /* stereo input */
102  byte = (t->audmode == V4L2_TUNER_MODE_MONO) ?
104  else { /* bilingual */
105  switch (t->audmode) {
107  byte = TDA9840_SET_BOTH;
108  break;
110  byte = TDA9840_SET_LANG2;
111  break;
112  default:
113  byte = TDA9840_SET_LANG1;
114  break;
115  }
116  }
117  v4l2_dbg(1, debug, sd, "TDA9840_SWITCH: 0x%02x\n", byte);
118  tda9840_write(sd, SWITCH, byte);
119  return 0;
120 }
121 
122 static int tda9840_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *t)
123 {
124  int stat = tda9840_status(sd);
125 
126  if (stat < 0)
127  return stat;
128 
130 
131  switch (stat & 0x60) {
132  case 0x00:
134  break;
135  case 0x20:
137  break;
138  case 0x40:
140  break;
141  default: /* Incorrect detect */
143  break;
144  }
145  return 0;
146 }
147 
148 static int tda9840_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
149 {
150  struct i2c_client *client = v4l2_get_subdevdata(sd);
151 
152  return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TDA9840, 0);
153 }
154 
155 /* ----------------------------------------------------------------------- */
156 
157 static const struct v4l2_subdev_core_ops tda9840_core_ops = {
158  .g_chip_ident = tda9840_g_chip_ident,
159 };
160 
161 static const struct v4l2_subdev_tuner_ops tda9840_tuner_ops = {
162  .s_tuner = tda9840_s_tuner,
163  .g_tuner = tda9840_g_tuner,
164 };
165 
166 static const struct v4l2_subdev_ops tda9840_ops = {
167  .core = &tda9840_core_ops,
168  .tuner = &tda9840_tuner_ops,
169 };
170 
171 /* ----------------------------------------------------------------------- */
172 
173 static int tda9840_probe(struct i2c_client *client,
174  const struct i2c_device_id *id)
175 {
176  struct v4l2_subdev *sd;
177 
178  /* let's see whether this adapter can support what we need */
179  if (!i2c_check_functionality(client->adapter,
182  return -EIO;
183 
184  v4l_info(client, "chip found @ 0x%x (%s)\n",
185  client->addr << 1, client->adapter->name);
186 
187  sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
188  if (sd == NULL)
189  return -ENOMEM;
190  v4l2_i2c_subdev_init(sd, client, &tda9840_ops);
191 
192  /* set initial values for level & stereo - adjustment, mode */
193  tda9840_write(sd, LEVEL_ADJUST, 0);
194  tda9840_write(sd, STEREO_ADJUST, 0);
195  tda9840_write(sd, SWITCH, TDA9840_SET_STEREO);
196  return 0;
197 }
198 
199 static int tda9840_remove(struct i2c_client *client)
200 {
201  struct v4l2_subdev *sd = i2c_get_clientdata(client);
202 
204  kfree(sd);
205  return 0;
206 }
207 
208 static const struct i2c_device_id tda9840_id[] = {
209  { "tda9840", 0 },
210  { }
211 };
212 MODULE_DEVICE_TABLE(i2c, tda9840_id);
213 
214 static struct i2c_driver tda9840_driver = {
215  .driver = {
216  .owner = THIS_MODULE,
217  .name = "tda9840",
218  },
219  .probe = tda9840_probe,
220  .remove = tda9840_remove,
221  .id_table = tda9840_id,
222 };
223 
224 module_i2c_driver(tda9840_driver);