xref: /openbmc/linux/drivers/media/i2c/tda9840.c (revision 2cf1c348)
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 
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 
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 
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 
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 
152 static int tda9840_probe(struct i2c_client *client,
153 			  const struct i2c_device_id *id)
154 {
155 	struct v4l2_subdev *sd;
156 
157 	/* let's see whether this adapter can support what we need */
158 	if (!i2c_check_functionality(client->adapter,
159 			I2C_FUNC_SMBUS_READ_BYTE_DATA |
160 			I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
161 		return -EIO;
162 
163 	v4l_info(client, "chip found @ 0x%x (%s)\n",
164 			client->addr << 1, client->adapter->name);
165 
166 	sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
167 	if (sd == NULL)
168 		return -ENOMEM;
169 	v4l2_i2c_subdev_init(sd, client, &tda9840_ops);
170 
171 	/* set initial values for level & stereo - adjustment, mode */
172 	tda9840_write(sd, LEVEL_ADJUST, 0);
173 	tda9840_write(sd, STEREO_ADJUST, 0);
174 	tda9840_write(sd, SWITCH, TDA9840_SET_STEREO);
175 	return 0;
176 }
177 
178 static int tda9840_remove(struct i2c_client *client)
179 {
180 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
181 
182 	v4l2_device_unregister_subdev(sd);
183 	return 0;
184 }
185 
186 static const struct i2c_device_id tda9840_id[] = {
187 	{ "tda9840", 0 },
188 	{ }
189 };
190 MODULE_DEVICE_TABLE(i2c, tda9840_id);
191 
192 static struct i2c_driver tda9840_driver = {
193 	.driver = {
194 		.name	= "tda9840",
195 	},
196 	.probe		= tda9840_probe,
197 	.remove		= tda9840_remove,
198 	.id_table	= tda9840_id,
199 };
200 
201 module_i2c_driver(tda9840_driver);
202