saa7113.c

这是一个Linux下的USB摄像头捕捉程序

		switch (*iarg) {

		case VIDEO_MODE_NTSC:
			saa7113_write(client, 0x08,
				      (decoder->reg[0x08] & 0x3f) | 0x40);
			saa7113_write(client, 0x0e,
				      (decoder->reg[0x0e] & 0x8f));
			break;

		case VIDEO_MODE_PAL:
			saa7113_write(client, 0x08,
				      (decoder->reg[0x08] & 0x3f) | 0x00);
			saa7113_write(client, 0x0e,
				      (decoder->reg[0x0e] & 0x8f));
			break;

		case VIDEO_MODE_SECAM:
			saa7113_write(client, 0x08,
				      (decoder->reg[0x0e] & 0x3f) | 0x00);
			saa7113_write(client, 0x0e,
				      (decoder->reg[0x0e] & 0x8f) | 0x50);
			break;

		case VIDEO_MODE_AUTO:
			saa7113_write(client, 0x08,
				      (decoder->reg[0x08] & 0x3f) | 0x80);
			saa7113_write(client, 0x0e,
				      (decoder->reg[0x0e] & 0x8f));
			break;

		default:
			return -EINVAL;

		}
		decoder->norm = *iarg;
	}
		break;

	case DECODER_SET_INPUT:
	{
		int *iarg = arg;

		if (*iarg < 0 || *iarg > 7) {
			return -EINVAL;
		}

		if (decoder->input != *iarg) {
			decoder->input = *iarg;
			/* select mode */
			saa7113_write(client, 0x02,
				      (decoder->
				       reg[0x02] & 0xf8) | decoder->input);
			/* bypass chrominance trap for modes 4..7 */
			saa7113_write(client, 0x09,
				      (decoder->
				       reg[0x09] & 0x7f) | ((decoder->
							     input >
							     3) ? 0x80 :
							    0));
		}
	}
		break;

	case DECODER_SET_OUTPUT:
	{
		int *iarg = arg;

		/* not much choice of outputs */
		if (*iarg != 0) {
			return -EINVAL;
		}
	}
		break;

	case DECODER_ENABLE_OUTPUT:
	{
		int *iarg = arg;
		int enable = (*iarg != 0);

		if (decoder->enable != enable) {
			decoder->enable = enable;

			/* RJ: If output should be disabled (for
			 * playing videos), we also need a open PLL.
			 * The input is set to 0 (where no input
			 * source is connected), although this
			 * is not necessary.
			 *
			 * If output should be enabled, we have to
			 * reverse the above.
			 */

			if (decoder->enable) {
				saa7113_write(client, 0x02,
					      (decoder->
					       reg[0x02] & 0xf8) |
					      decoder->input);
				saa7113_write(client, 0x08,
					      (decoder->reg[0x08] & 0xfb));
				saa7113_write(client, 0x11,
					      (decoder->
					       reg[0x11] & 0xf3) | 0x0c);
			} else {
				saa7113_write(client, 0x02,
					      (decoder->reg[0x02] & 0xf8));
				saa7113_write(client, 0x08,
					      (decoder->
					       reg[0x08] & 0xfb) | 0x04);
				saa7113_write(client, 0x11,
					      (decoder->reg[0x11] & 0xf3));
			}
		}
	}
		break;

	case DECODER_SET_PICTURE:
	{
		struct video_picture *pic = arg;

		if (decoder->bright != pic->brightness) {
			/* We want 0 to 255 we get 0-65535 */
			decoder->bright = pic->brightness;
			saa7113_write(client, 0x0a, decoder->bright >> 8);
		}
		if (decoder->contrast != pic->contrast) {
			/* We want 0 to 127 we get 0-65535 */
			decoder->contrast = pic->contrast;
			saa7113_write(client, 0x0b,
				      decoder->contrast >> 9);
		}
		if (decoder->sat != pic->colour) {
			/* We want 0 to 127 we get 0-65535 */
			decoder->sat = pic->colour;
			saa7113_write(client, 0x0c, decoder->sat >> 9);
		}
		if (decoder->hue != pic->hue) {
			/* We want -128 to 127 we get 0-65535 */
			decoder->hue = pic->hue;
			saa7113_write(client, 0x0d,
				      (decoder->hue - 32768) >> 8);
		}
	}
		break;

	default:
		return -EINVAL;
	}

	return 0;
}

/* ----------------------------------------------------------------------- */

/*
 * Generic i2c probe
 * concerning the addresses: i2c wants 7 bit (without the r/w bit), so '>>1'
 */
static unsigned short normal_i2c[] = { I2C_SAA7113 >> 1, I2C_CLIENT_END };
static unsigned short normal_i2c_range[] = { I2C_CLIENT_END };

static unsigned short probe[2] = { I2C_CLIENT_END, I2C_CLIENT_END };
static unsigned short probe_range[2] = { I2C_CLIENT_END, I2C_CLIENT_END };
static unsigned short ignore[2] = { I2C_CLIENT_END, I2C_CLIENT_END };
static unsigned short ignore_range[2] = { I2C_CLIENT_END, I2C_CLIENT_END };
static unsigned short force[2] = { I2C_CLIENT_END , I2C_CLIENT_END };
                                                                                
static struct i2c_client_address_data addr_data = {
	.normal_i2c		= normal_i2c,
	.normal_i2c_range	= normal_i2c_range,
	.probe			= probe,
	.probe_range		= probe_range,
	.ignore			= ignore,
	.ignore_range		= ignore_range,
	.force			= force
};

#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 11)
static int saa7113_i2c_id = 0;
#endif

static struct i2c_driver i2c_driver_saa7113;

static int
saa7113_detect_client (struct i2c_adapter *adapter,
		       int                 address,
		       int                 kind)
{
	int i;
	struct i2c_client *client;
	struct saa7113 *decoder;
	struct video_decoder_init vdi;

	dprintk(1,
		KERN_INFO
		"saa7113.c: detecting saa7113 client on address 0x%x\n",
		address << 1);

	/* Check if the adapter supports the needed features */
	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return 0;

	client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
	if (client == 0)
		return -ENOMEM;
	memset(client, 0, sizeof(struct i2c_client));
	client->addr = address;
	client->adapter = adapter;
	client->driver = &i2c_driver_saa7113;
	client->flags = I2C_CLIENT_ALLOW_USE;
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 11)
	client->id = saa7113_i2c_id++;
	snprintf(I2C_NAME(client), sizeof(I2C_NAME(client)) - 1,
	"saa7111[%d]", client->id); 
#else
	strlcpy(I2C_NAME(client), "saa7113", sizeof(I2C_NAME(client)));
#endif
	decoder = kmalloc(sizeof(struct saa7113), GFP_KERNEL);
	if (decoder == NULL) {
		kfree(client);
		return -ENOMEM;
	}
	memset(decoder, 0, sizeof(struct saa7113));
	decoder->norm = VIDEO_MODE_NTSC;
	decoder->input = 0;
	decoder->enable = 1;
	decoder->bright = 32768;
	decoder->contrast = 32768;
	decoder->hue = 32768;
	decoder->sat = 32768;
	i2c_set_clientdata(client, decoder);

	i = i2c_attach_client(client);
	if (i) {
		kfree(client);
		kfree(decoder);
		return i;
	}

	vdi.data = saa7113_i2c_init;
	vdi.len = sizeof(saa7113_i2c_init);
	i = saa7113_init_decoder(client, &vdi);
	if (i < 0) {
		dprintk(1, KERN_ERR "%s_attach error: init status %d\n",
			I2C_NAME(client), i);
	} else {
		dprintk(1,
			KERN_INFO
			"%s_attach: chip version %x at address 0x%x\n",
			I2C_NAME(client), saa7113_read(client, 0x00) >> 4,
			client->addr << 1);
	}

	return 0;
}

static int
saa7113_attach_adapter (struct i2c_adapter *adapter)
{
	dprintk(1,
		KERN_INFO
		"saa7113.c: starting probe for adapter %s (0x%x)\n",
		I2C_NAME(adapter), adapter->id);
	return i2c_probe(adapter, &addr_data, &saa7113_detect_client);
}

static int
saa7113_detach_client (struct i2c_client *client)
{
	struct saa7113 *decoder = i2c_get_clientdata(client);
	int err;

	err = i2c_detach_client(client);
	if (err) {
		return err;
	}

	kfree(decoder);
	kfree(client);

	return 0;
}

/* ----------------------------------------------------------------------- */

static struct i2c_driver i2c_driver_saa7113 = {
	.owner = THIS_MODULE,
	.name = "saa7113",

	.id = I2C_DRIVERID_SAA7113,
	.flags = I2C_DF_NOTIFY,

	.attach_adapter = saa7113_attach_adapter,
	.detach_client = saa7113_detach_client,
	.command = saa7113_command,
};

static int __init
saa7113_init (void)
{
	return i2c_add_driver(&i2c_driver_saa7113);
}

static void __exit
saa7113_exit (void)
{
	i2c_del_driver(&i2c_driver_saa7113);
}

module_init(saa7113_init);
module_exit(saa7113_exit);