v4l2_q_init(struct v4l2_queue *q){	if (q == NULL)		return;	q->qlock = rw_lock_unlocked;	q->forw = (struct v4l2_q_node *)q;	q->back = (struct v4l2_q_node *)q;}voidv4l2_q_add_head(struct v4l2_queue *q, struct v4l2_q_node *node){	unsigned long flags;	if (q == NULL || node == NULL)		return;	if (q->forw == NULL || q->back == NULL)		v4l2_q_init(q);	write_lock_irqsave(&(q->qlock), flags);	node->forw = q->forw;	node->back = (struct v4l2_q_node *)q;	q->forw->back = node;	q->forw = node;	write_unlock_irqrestore(&(q->qlock), flags);}voidv4l2_q_add_tail(struct v4l2_queue *q, struct v4l2_q_node *node){	unsigned long flags;	if (q == NULL || node == NULL)		return;	if (q->forw == NULL || q->back == NULL)		v4l2_q_init(q);	write_lock_irqsave(&(q->qlock), flags);	node->forw = (struct v4l2_q_node *)q;	node->back = q->back;	q->back->forw = node;	q->back = node;	write_unlock_irqrestore(&(q->qlock), flags);}void *v4l2_q_del_head(struct v4l2_queue *q){	unsigned long flags;	struct v4l2_q_node *node;	if (q == NULL)		return NULL;	write_lock_irqsave(&(q->qlock), flags);	if (q->forw == NULL || q->back == NULL ||	    q->forw == (struct v4l2_q_node *)q ||	    q->back == (struct v4l2_q_node *)q)	{		write_unlock_irqrestore(&(q->qlock), flags);		return NULL;	}	node = q->forw;	node->forw->back = (struct v4l2_q_node *)q;	q->forw = node->forw;	node->forw = NULL;	node->back = NULL;	write_unlock_irqrestore(&(q->qlock), flags);	return node;}void *v4l2_q_del_tail(struct v4l2_queue *q){	unsigned long flags;	struct v4l2_q_node *node;	if (q == NULL)		return NULL;	write_lock_irqsave(&(q->qlock), flags);	if (q->forw == NULL || q->back == NULL ||	    q->forw == (struct v4l2_q_node *)q ||	    q->back == (struct v4l2_q_node *)q)	{		write_unlock_irqrestore(&(q->qlock), flags);		return NULL;	}	node = q->back;	node->back->forw = (struct v4l2_q_node *)q;	q->back = node->back;	node->forw = NULL;	node->back = NULL;	write_unlock_irqrestore(&(q->qlock), flags);	return node;}void *v4l2_q_peek_head(struct v4l2_queue *q){	unsigned long flags;	struct v4l2_q_node *node;	read_lock_irqsave(&(q->qlock), flags);	if (q == NULL || q->forw == NULL || q->forw == (struct v4l2_q_node *)q)	{		read_unlock_irqrestore(&(q->qlock), flags);		return NULL;	}	node = q->forw;	read_unlock_irqrestore(&(q->qlock), flags);	return node;}void *v4l2_q_peek_tail(struct v4l2_queue *q){	unsigned long flags;	struct v4l2_q_node *node;	read_lock_irqsave(&(q->qlock), flags);	if (q == NULL || q->back == NULL || q->back == (struct v4l2_q_node *)q)	{		read_unlock_irqrestore(&(q->qlock), flags);		return NULL;	}	node = q->back;	read_unlock_irqrestore(&(q->qlock), flags);	return node;}void *v4l2_q_yank_node(struct v4l2_queue *q, struct v4l2_q_node *node){	unsigned long flags;	struct v4l2_q_node *t;	if (v4l2_q_peek_head(q) == NULL || node == NULL)		return NULL;	write_lock_irqsave(&(q->qlock), flags);	for (t = q->forw; t != (struct v4l2_q_node *)q; t = t->forw)		if (t == node)		{			node->back->forw = node->forw;			node->forw->back = node->back;			node->forw = NULL;			node->back = NULL;			write_unlock_irqrestore(&(q->qlock), flags);			return node;		}	write_unlock_irqrestore(&(q->qlock), flags);	return NULL;}intv4l2_q_last(struct v4l2_queue *q){/*  This function by Olivier Carmona  */	unsigned long flags;	read_lock_irqsave(&(q->qlock), flags);	if (q == NULL)	{		read_unlock_irqrestore(&(q->qlock), flags);		return -1;	}	if (q->forw == NULL || q->back == NULL ||	    q->forw == (struct v4l2_q_node *)q ||	    q->back == (struct v4l2_q_node *)q)	{		read_unlock_irqrestore(&(q->qlock), flags);		return -1;	}	if (q->forw == q->back)	{		read_unlock_irqrestore(&(q->qlock), flags);		return 1;	}	read_unlock_irqrestore(&(q->qlock), flags);	return 0;}/* *  Math functions */u32v4l2_math_div6432(u64 a, u32 d, u32 *r){	u32 m = do_div(a, d);	if (r) *r = m;	return (u32)a;}unsigned longv4l2_timestamp_divide(stamp_t t, unsigned long p_100ns){	/*  Note: 't' is in 1ns units, 'p_100ns' is in 100ns units, */	/*  and the quotient is rounded  */	u64	p;	p = (u64)p_100ns * 100;  /* 1ns units */	t >>= 6;      /*  /64 to allow p_100ns longer than 4 secs. */	p >>= 6;  /*  to keep quotient the same  */	return v4l2_math_div6432((u64)t + (p >> 1), (u32)p, NULL);}/*  Force the timestamp to be an integer multiple of p_100ns  */unsigned longv4l2_timestamp_correct(stamp_t *t, unsigned long p_100ns){	/*  Note: 't' is in 1ns units, 'p_100ns' is in 100ns units */	unsigned long	n;	n = v4l2_timestamp_divide((u64)*t, p_100ns);	*t = (u64)p_100ns * n * 100;	return n;}/* *	Master clock operations */intv4l2_masterclock_register(struct v4l2_clock *clock){	if (clock == NULL || clock->gettime == NULL)		return -1;	if (masterclock != NULL)		return -1;	masterclock = clock;	MOD_INC_USE_COUNT;	return 0;}voidv4l2_masterclock_unregister(struct v4l2_clock *clock){	if (clock != masterclock)		return;	masterclock = NULL;	MOD_DEC_USE_COUNT;}voidv4l2_masterclock_gettime(stamp_t *curr){	if (masterclock)		masterclock->gettime(curr);	else	{#if defined(CONFIG_UST) || defined(CONFIG_UST_MODULE)		ust_gettime(curr);#else		struct timeval	t;		stamp_t stamp;		do_gettimeofday(&t);		stamp = (stamp_t)t.tv_sec * 1000000 + t.tv_usec;		stamp *= 1000;		*curr = stamp;#endif	}}/* *  Video Standard Operations (contributed by Michael Schimek) *//* This is the recommended method to deal with the framerate fields. More    sophisticated drivers will access the fields directly. */unsigned intv4l2_video_std_fps(struct v4l2_standard *vs){ 	if (vs->framerate.numerator > 0)		return (((vs->framerate.denominator << 8) / 			 vs->framerate.numerator) + 			(1 << 7)) / (1 << 8);	return 0;}/*  Compute the time per frame in 100ns units  */unsigned longv4l2_video_std_tpf(struct v4l2_standard *vs){	return v4l2_math_div6432(		(u64)vs->framerate.numerator * 10000000		+ vs->framerate.denominator / 2,		vs->framerate.denominator,		NULL);}/*  Used only in v4l2_video_std_confirm()  */static voidcatc1p2e6(__u8 *s, char c, int n){	n /= 10000;	sprintf(s + strlen(s), "%c%d.%02d", c, n / 100, n % 100);}/* Verify the validity of the parameters of a v4l2_standard structure and   create the name and id from the other fields. It does not relieve a    driver from examining if it can fulfill the request.  Returns an    errno < 0 if inconsistent, 0 if an unknown but maybe usable format,    or the V4L2_STD_XXX_X value if a known standard. */intv4l2_video_std_confirm(struct v4l2_standard *vs){	unsigned int	rate  = 0;	unsigned int	lines = vs->framelines;	int		std   = 0;	strcpy(vs->name, "Unknown");	if (vs->reserved1 || vs->reserved2)		return -EINVAL;	if (vs->framerate.numerator > 0 &&		    vs->framerate.denominator > 0)		rate = v4l2_video_std_fps(vs);	if (vs->framelines >= 624 && vs->framelines <= 626)		lines = 625;	else if (vs->framelines >= 524 && vs->framelines <= 526)		lines = 525;	if (rate == 0 || lines == 0 || rate > 200)		return -EINVAL;	switch (vs->colorstandard)	{	case V4L2_COLOR_STD_PAL:		strcpy(vs->name, "PAL");		if (rate == 25 && lines == 625)			switch (vs->colorstandard_data.pal.colorsubcarrier)			{			case V4L2_COLOR_SUBC_PAL_N:				strcpy(vs->name, "PAL-N");				if (vs->transmission & ~V4L2_TRANSM_STD_N)					return -EINVAL;				return V4L2_STD_PAL_N;			case V4L2_COLOR_SUBC_PAL:				if (vs->transmission & 				    ~(V4L2_TRANSM_STD_B | V4L2_TRANSM_STD_G |				      V4L2_TRANSM_STD_H | V4L2_TRANSM_STD_I |				      V4L2_TRANSM_STD_D))					return -EINVAL;				std = V4L2_STD_PAL;				goto addtransm;			}		else if (rate == 30 && lines == 525)			switch (vs->colorstandard_data.pal.colorsubcarrier)			{			case V4L2_COLOR_SUBC_PAL_M:				strcpy(vs->name, "PAL-M");				if (vs->transmission & ~V4L2_TRANSM_STD_M)					return -EINVAL;				return V4L2_STD_PAL_M;			case V4L2_COLOR_SUBC_PAL:				strcpy(vs->name, "PAL-60");				if (vs->transmission)					return -EINVAL;				return V4L2_STD_PAL_60;			}		if (vs->transmission)			return -EINVAL;		catc1p2e6(vs->name, ' ', 			  vs->colorstandard_data.pal.colorsubcarrier);		break;	case V4L2_COLOR_STD_NTSC:		strcpy(vs->name, "NTSC");		if (rate == 25 && lines == 625)			switch (vs->colorstandard_data.ntsc.colorsubcarrier)			{			case V4L2_COLOR_SUBC_NTSC:				strcpy(vs->name, "NTSC-N");				if (vs->transmission & ~V4L2_TRANSM_STD_N)					return -EINVAL;				return V4L2_STD_NTSC_N;			}		else if (rate == 30 && lines == 525)			switch (vs->colorstandard_data.ntsc.colorsubcarrier)			{			case V4L2_COLOR_SUBC_NTSC:				if (vs->transmission & ~V4L2_TRANSM_STD_M)					return -EINVAL;				std = V4L2_STD_NTSC;				goto addtransm;			case V4L2_COLOR_SUBC_PAL:				strcpy(vs->name, "NTSC-44");				if (vs->transmission)					return -EINVAL;				return V4L2_STD_NTSC_44;			}		if (vs->transmission)			return -EINVAL;		catc1p2e6(vs->name, ' ', 			  vs->colorstandard_data.ntsc.colorsubcarrier);		break;	case V4L2_COLOR_STD_SECAM:		strcpy(vs->name, "SECAM");		if (rate == 25 && lines == 625)			if (vs->colorstandard_data.secam.f0b == 			    V4L2_COLOR_SUBC_SECAMB &&			    vs->colorstandard_data.secam.f0r == 			    V4L2_COLOR_SUBC_SECAMR)			{				if (vs->transmission &				    ~(V4L2_TRANSM_STD_B | V4L2_TRANSM_STD_D |			              V4L2_TRANSM_STD_G | V4L2_TRANSM_STD_K |			              V4L2_TRANSM_STD_K1 | V4L2_TRANSM_STD_L))					return -EINVAL;				std = V4L2_STD_SECAM;				goto addtransm;			}		if (vs->transmission)			return -EINVAL;		catc1p2e6(vs->name, ' ', vs->colorstandard_data.secam.f0b);		catc1p2e6(vs->name, '/', vs->colorstandard_data.secam.f0r);		break;	default:		return -EINVAL;	}        sprintf(vs->name + strlen(vs->name), " %d/%d",	        vs->framelines, rate);	return std; addtransm:	if (vs->transmission) strcat(vs->name, "-");        if (vs->transmission & V4L2_TRANSM_STD_B) strcat(vs->name, "B/");        if (vs->transmission & V4L2_TRANSM_STD_G) strcat(vs->name, "G/");        if (vs->transmission & V4L2_TRANSM_STD_H) strcat(vs->name, "H/");	if (vs->transmission & V4L2_TRANSM_STD_I) strcat(vs->name, "I/");	if (vs->transmission & V4L2_TRANSM_STD_D) strcat(vs->name, "D/");	if (vs->transmission & V4L2_TRANSM_STD_K) strcat(vs->name, "K/");	if (vs->transmission & V4L2_TRANSM_STD_K1) strcat(vs->name, "K1/");	if (vs->transmission & V4L2_TRANSM_STD_L) strcat(vs->name, "L/");	if (vs->transmission & V4L2_TRANSM_STD_M) strcat(vs->name, "M/");	if (vs->transmission & V4L2_TRANSM_STD_N) strcat(vs->name, "N/");	if (vs->name[strlen(vs->name) - 1] == '/')		vs->name[strlen(vs->name) - 1] = 0;    	return std;}/* Fill in the fields of a v4l2_standard structure according to the   'id' and 'transmission' parameters.  Returns negative on error.  */intv4l2_video_std_construct(struct v4l2_standard *vs,			 int id, __u32 transmission){	memset(vs, 0, sizeof(struct v4l2_standard));	vs->framerate.numerator = 1;	vs->framerate.denominator = 25;	vs->framelines = 625;	switch (id)	{	case V4L2_STD_PAL_60:		vs->framerate.numerator = 1001;		vs->framerate.denominator = 30000;		vs->framelines = 525;		/* fall thru */	case V4L2_STD_PAL:		vs->colorstandard = V4L2_COLOR_STD_PAL;		vs->colorstandard_data.pal.colorsubcarrier =			V4L2_COLOR_SUBC_PAL;		break;	case V4L2_STD_PAL_M:		vs->framerate.numerator = 1001;		vs->framerate.denominator = 30000;		vs->framelines = 525;		vs->colorstandard = V4L2_COLOR_STD_PAL;		vs->colorstandard_data.pal.colorsubcarrier = 			V4L2_COLOR_SUBC_PAL_M;		break;	case V4L2_STD_PAL_N:		vs->colorstandard = V4L2_COLOR_STD_PAL;		vs->colorstandard_data.pal.colorsubcarrier = 			V4L2_COLOR_SUBC_PAL_N;		break;	case V4L2_STD_NTSC:		vs->framerate.numerator = 1001;		vs->framerate.denominator = 30000;		vs->framelines = 525;		/* fall thru */	case V4L2_STD_NTSC_N:		vs->colorstandard = V4L2_COLOR_STD_NTSC;		vs->colorstandard_data.ntsc.colorsubcarrier = 			V4L2_COLOR_SUBC_NTSC;		break;	case V4L2_STD_NTSC_44:		vs->framerate.numerator = 1001;		vs->framerate.denominator = 30000;		vs->framelines = 525;		vs->colorstandard = V4L2_COLOR_STD_NTSC;		vs->colorstandard_data.ntsc.colorsubcarrier = 			V4L2_COLOR_SUBC_PAL;		break;	case V4L2_STD_SECAM:		vs->colorstandard = V4L2_COLOR_STD_SECAM;		vs->colorstandard_data.secam.f0b = V4L2_COLOR_SUBC_SECAMB;		vs->colorstandard_data.secam.f0r = V4L2_COLOR_SUBC_SECAMR;		break;	default:		return -EINVAL;	}	vs->transmission = transmission;	return v4l2_video_std_confirm(vs);}/*---------------------------------------*/EXPORT_SYMBOL(v4l2_register_device);EXPORT_SYMBOL(v4l2_unregister_device);EXPORT_SYMBOL(v4l2_v4l_compat_register);EXPORT_SYMBOL(v4l2_v4l_compat_unregister);EXPORT_SYMBOL(v4l2_version);EXPORT_SYMBOL(v4l2_major_number);EXPORT_SYMBOL(v4l2_device_from_minor);EXPORT_SYMBOL(v4l2_device_from_file);EXPORT_SYMBOL(v4l2_openid_from_file);EXPORT_SYMBOL(v4l2_vmalloc_to_bus);EXPORT_SYMBOL(v4l2_vmalloc_to_page);EXPORT_SYMBOL(v4l2_q_init);EXPORT_SYMBOL(v4l2_q_add_head);EXPORT_SYMBOL(v4l2_q_add_tail);EXPORT_SYMBOL(v4l2_q_del_head);EXPORT_SYMBOL(v4l2_q_del_tail);EXPORT_SYMBOL(v4l2_q_peek_head);EXPORT_SYMBOL(v4l2_q_peek_tail);EXPORT_SYMBOL(v4l2_q_yank_node);EXPORT_SYMBOL(v4l2_q_last);EXPORT_SYMBOL(v4l2_math_div6432);EXPORT_SYMBOL(v4l2_timestamp_divide);EXPORT_SYMBOL(v4l2_timestamp_correct);EXPORT_SYMBOL(v4l2_masterclock_register);EXPORT_SYMBOL(v4l2_masterclock_unregister);EXPORT_SYMBOL(v4l2_masterclock_gettime);EXPORT_SYMBOL(v4l2_video_std_fps);EXPORT_SYMBOL(v4l2_video_std_tpf);EXPORT_SYMBOL(v4l2_video_std_confirm);EXPORT_SYMBOL(v4l2_video_std_construct);EXPORT_SYMBOL(video_register_device);EXPORT_SYMBOL(video_unregister_device);