1  // SPDX-License-Identifier: GPL-2.0-or-later
2   /*
3      tda9840 - i2c-driver for the tda9840 by SGS Thomson
4  
5      Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
6      Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
7  
8      The tda9840 is a stereo/dual sound processor with digital
9      identification. It can be found at address 0x84 on the i2c-bus.
10  
11      For detailed information download the specifications directly
12      from SGS Thomson at http://www.st.com
13  
14    */
15  
16  
17  #include <linux/module.h>
18  #include <linux/ioctl.h>
19  #include <linux/slab.h>
20  #include <linux/i2c.h>
21  #include <media/v4l2-device.h>
22  
23  MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
24  MODULE_DESCRIPTION("tda9840 driver");
25  MODULE_LICENSE("GPL");
26  
27  static int debug;
28  module_param(debug, int, 0644);
29  
30  MODULE_PARM_DESC(debug, "Debug level (0-1)");
31  
32  #define	SWITCH		0x00
33  #define	LEVEL_ADJUST	0x02
34  #define	STEREO_ADJUST	0x03
35  #define	TEST		0x04
36  
37  #define TDA9840_SET_MUTE                0x00
38  #define TDA9840_SET_MONO                0x10
39  #define TDA9840_SET_STEREO              0x2a
40  #define TDA9840_SET_LANG1               0x12
41  #define TDA9840_SET_LANG2               0x1e
42  #define TDA9840_SET_BOTH                0x1a
43  #define TDA9840_SET_BOTH_R              0x16
44  #define TDA9840_SET_EXTERNAL            0x7a
45  
46  
tda9840_write(struct v4l2_subdev * sd,u8 reg,u8 val)47  static void tda9840_write(struct v4l2_subdev *sd, u8 reg, u8 val)
48  {
49  	struct i2c_client *client = v4l2_get_subdevdata(sd);
50  
51  	if (i2c_smbus_write_byte_data(client, reg, val))
52  		v4l2_dbg(1, debug, sd, "error writing %02x to %02x\n",
53  				val, reg);
54  }
55  
tda9840_status(struct v4l2_subdev * sd)56  static int tda9840_status(struct v4l2_subdev *sd)
57  {
58  	struct i2c_client *client = v4l2_get_subdevdata(sd);
59  	int rc;
60  	u8 byte;
61  
62  	rc = i2c_master_recv(client, &byte, 1);
63  	if (rc != 1) {
64  		v4l2_dbg(1, debug, sd,
65  			"i2c_master_recv() failed\n");
66  		if (rc < 0)
67  			return rc;
68  		return -EIO;
69  	}
70  
71  	if (byte & 0x80) {
72  		v4l2_dbg(1, debug, sd,
73  			"TDA9840_DETECT: register contents invalid\n");
74  		return -EINVAL;
75  	}
76  
77  	v4l2_dbg(1, debug, sd, "TDA9840_DETECT: byte: 0x%02x\n", byte);
78  	return byte & 0x60;
79  }
80  
tda9840_s_tuner(struct v4l2_subdev * sd,const struct v4l2_tuner * t)81  static int tda9840_s_tuner(struct v4l2_subdev *sd, const struct v4l2_tuner *t)
82  {
83  	int stat = tda9840_status(sd);
84  	int byte;
85  
86  	if (t->index)
87  		return -EINVAL;
88  
89  	stat = stat < 0 ? 0 : stat;
90  	if (stat == 0 || stat == 0x60) /* mono input */
91  		byte = TDA9840_SET_MONO;
92  	else if (stat == 0x40) /* stereo input */
93  		byte = (t->audmode == V4L2_TUNER_MODE_MONO) ?
94  			TDA9840_SET_MONO : TDA9840_SET_STEREO;
95  	else { /* bilingual */
96  		switch (t->audmode) {
97  		case V4L2_TUNER_MODE_LANG1_LANG2:
98  			byte = TDA9840_SET_BOTH;
99  			break;
100  		case V4L2_TUNER_MODE_LANG2:
101  			byte = TDA9840_SET_LANG2;
102  			break;
103  		default:
104  			byte = TDA9840_SET_LANG1;
105  			break;
106  		}
107  	}
108  	v4l2_dbg(1, debug, sd, "TDA9840_SWITCH: 0x%02x\n", byte);
109  	tda9840_write(sd, SWITCH, byte);
110  	return 0;
111  }
112  
tda9840_g_tuner(struct v4l2_subdev * sd,struct v4l2_tuner * t)113  static int tda9840_g_tuner(struct v4l2_subdev *sd, struct v4l2_tuner *t)
114  {
115  	int stat = tda9840_status(sd);
116  
117  	if (stat < 0)
118  		return stat;
119  
120  	t->rxsubchans = V4L2_TUNER_SUB_MONO;
121  
122  	switch (stat & 0x60) {
123  	case 0x00:
124  		t->rxsubchans = V4L2_TUNER_SUB_MONO;
125  		break;
126  	case 0x20:
127  		t->rxsubchans = V4L2_TUNER_SUB_LANG1 | V4L2_TUNER_SUB_LANG2;
128  		break;
129  	case 0x40:
130  		t->rxsubchans = V4L2_TUNER_SUB_STEREO | V4L2_TUNER_SUB_MONO;
131  		break;
132  	default: /* Incorrect detect */
133  		t->rxsubchans = V4L2_TUNER_MODE_MONO;
134  		break;
135  	}
136  	return 0;
137  }
138  
139  /* ----------------------------------------------------------------------- */
140  
141  static const struct v4l2_subdev_tuner_ops tda9840_tuner_ops = {
142  	.s_tuner = tda9840_s_tuner,
143  	.g_tuner = tda9840_g_tuner,
144  };
145  
146  static const struct v4l2_subdev_ops tda9840_ops = {
147  	.tuner = &tda9840_tuner_ops,
148  };
149  
150  /* ----------------------------------------------------------------------- */
151  
tda9840_probe(struct i2c_client * client)152  static int tda9840_probe(struct i2c_client *client)
153  {
154  	struct v4l2_subdev *sd;
155  
156  	/* let's see whether this adapter can support what we need */
157  	if (!i2c_check_functionality(client->adapter,
158  			I2C_FUNC_SMBUS_READ_BYTE_DATA |
159  			I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
160  		return -EIO;
161  
162  	v4l_info(client, "chip found @ 0x%x (%s)\n",
163  			client->addr << 1, client->adapter->name);
164  
165  	sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
166  	if (sd == NULL)
167  		return -ENOMEM;
168  	v4l2_i2c_subdev_init(sd, client, &tda9840_ops);
169  
170  	/* set initial values for level & stereo - adjustment, mode */
171  	tda9840_write(sd, LEVEL_ADJUST, 0);
172  	tda9840_write(sd, STEREO_ADJUST, 0);
173  	tda9840_write(sd, SWITCH, TDA9840_SET_STEREO);
174  	return 0;
175  }
176  
tda9840_remove(struct i2c_client * client)177  static void tda9840_remove(struct i2c_client *client)
178  {
179  	struct v4l2_subdev *sd = i2c_get_clientdata(client);
180  
181  	v4l2_device_unregister_subdev(sd);
182  }
183  
184  static const struct i2c_device_id tda9840_id[] = {
185  	{ "tda9840" },
186  	{ }
187  };
188  MODULE_DEVICE_TABLE(i2c, tda9840_id);
189  
190  static struct i2c_driver tda9840_driver = {
191  	.driver = {
192  		.name	= "tda9840",
193  	},
194  	.probe		= tda9840_probe,
195  	.remove		= tda9840_remove,
196  	.id_table	= tda9840_id,
197  };
198  
199  module_i2c_driver(tda9840_driver);
200