tea6415c.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2 /*
  3    tea6415c - i2c-driver for the tea6415c 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 tea6415c is a bus controlled video-matrix-switch
  9    with 8 inputs and 6 outputs.
 10    It is cascadable, i.e. it can be found at the addresses
 11    0x86 and 0x06 on the i2c-bus.
 12
 13    For detailed information download the specifications directly
 14    from SGS Thomson at http://www.st.com
 15
 16  */
 17
 18
 19#include <linux/module.h>
 20#include <linux/ioctl.h>
 21#include <linux/slab.h>
 22#include <linux/i2c.h>
 23#include <media/v4l2-device.h>
 24#include "tea6415c.h"
 25
 26MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
 27MODULE_DESCRIPTION("tea6415c driver");
 28MODULE_LICENSE("GPL");
 29
 30static int debug;
 31module_param(debug, int, 0644);
 32
 33MODULE_PARM_DESC(debug, "Debug level (0-1)");
 34
 35
 36/* makes a connection between the input-pin 'i' and the output-pin 'o' */
 37static int tea6415c_s_routing(struct v4l2_subdev *sd,
 38			      u32 i, u32 o, u32 config)
 39{
 40	struct i2c_client *client = v4l2_get_subdevdata(sd);
 41	u8 byte = 0;
 42	int ret;
 43
 44	v4l2_dbg(1, debug, sd, "i=%d, o=%d\n", i, o);
 45
 46	/* check if the pins are valid */
 47	if (0 == ((1 == i ||  3 == i ||  5 == i ||  6 == i ||  8 == i || 10 == i || 20 == i || 11 == i)
 48	      && (18 == o || 17 == o || 16 == o || 15 == o || 14 == o || 13 == o)))
 49		return -EINVAL;
 50
 51	/* to understand this, have a look at the tea6415c-specs (p.5) */
 52	switch (o) {
 53	case 18:
 54		byte = 0x00;
 55		break;
 56	case 14:
 57		byte = 0x20;
 58		break;
 59	case 16:
 60		byte = 0x10;
 61		break;
 62	case 17:
 63		byte = 0x08;
 64		break;
 65	case 15:
 66		byte = 0x18;
 67		break;
 68	case 13:
 69		byte = 0x28;
 70		break;
 71	}
 72
 73	switch (i) {
 74	case 5:
 75		byte |= 0x00;
 76		break;
 77	case 8:
 78		byte |= 0x04;
 79		break;
 80	case 3:
 81		byte |= 0x02;
 82		break;
 83	case 20:
 84		byte |= 0x06;
 85		break;
 86	case 6:
 87		byte |= 0x01;
 88		break;
 89	case 10:
 90		byte |= 0x05;
 91		break;
 92	case 1:
 93		byte |= 0x03;
 94		break;
 95	case 11:
 96		byte |= 0x07;
 97		break;
 98	}
 99
100	ret = i2c_smbus_write_byte(client, byte);
101	if (ret) {
102		v4l2_dbg(1, debug, sd,
103			"i2c_smbus_write_byte() failed, ret:%d\n", ret);
104		return -EIO;
105	}
106	return ret;
107}
108
109/* ----------------------------------------------------------------------- */
110
111static const struct v4l2_subdev_video_ops tea6415c_video_ops = {
112	.s_routing = tea6415c_s_routing,
113};
114
115static const struct v4l2_subdev_ops tea6415c_ops = {
116	.video = &tea6415c_video_ops,
117};
118
119static int tea6415c_probe(struct i2c_client *client)
120{
121	struct v4l2_subdev *sd;
122
123	/* let's see whether this adapter can support what we need */
124	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
125		return -EIO;
126
127	v4l_info(client, "chip found @ 0x%x (%s)\n",
128			client->addr << 1, client->adapter->name);
129	sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
130	if (sd == NULL)
131		return -ENOMEM;
132	v4l2_i2c_subdev_init(sd, client, &tea6415c_ops);
133	return 0;
134}
135
136static void tea6415c_remove(struct i2c_client *client)
137{
138	struct v4l2_subdev *sd = i2c_get_clientdata(client);
139
140	v4l2_device_unregister_subdev(sd);
141}
142
143static const struct i2c_device_id tea6415c_id[] = {
144	{ "tea6415c" },
145	{ }
146};
147MODULE_DEVICE_TABLE(i2c, tea6415c_id);
148
149static struct i2c_driver tea6415c_driver = {
150	.driver = {
151		.name	= "tea6415c",
152	},
153	.probe		= tea6415c_probe,
154	.remove		= tea6415c_remove,
155	.id_table	= tea6415c_id,
156};
157
158module_i2c_driver(tea6415c_driver);