tda9840.c

  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@kernel.org>
  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
 23MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 24MODULE_DESCRIPTION("tda9840 driver");
 25MODULE_LICENSE("GPL");
 26
 27static int debug;
 28module_param(debug, int, 0644);
 29
 30MODULE_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
 47static 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
 56static 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
 81static 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
113static 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
141static const struct v4l2_subdev_tuner_ops tda9840_tuner_ops = {
142	.s_tuner = tda9840_s_tuner,
143	.g_tuner = tda9840_g_tuner,
144};
145
146static const struct v4l2_subdev_ops tda9840_ops = {
147	.tuner = &tda9840_tuner_ops,
148};
149
150/* ----------------------------------------------------------------------- */
151
152static 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
177static 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
184static const struct i2c_device_id tda9840_id[] = {
185	{ "tda9840" },
186	{ }
187};
188MODULE_DEVICE_TABLE(i2c, tda9840_id);
189
190static 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
199module_i2c_driver(tda9840_driver);