Re: [REVIEWv3 PATCH 08/35] v4l2-ctrls: create type_ops.

[Mauro Carvalho Chehab <m.chehab@samsung.com>]

Em Mon, 17 Feb 2014 10:57:23 +0100
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Since complex controls can have non-standard types we need to be able to do
> type-specific checks etc. In order to make that easy type operations are added.
> There are four operations:
> 
> - equal: check if two values are equal
> - init: initialize a value
> - log: log the value
> - validate: validate a new value

So far, I failed to see why this is needed, as all code below is actually
related to non-complex controls, but your comment is confusing, saying that
this is related to complex controls.

Maybe a latter patch will help me to better understand this one.

> This patch uses the v4l2_ctrl_ptr union for the first time.

Then move v4l2_ctrl_ptr union addition to this patch.

> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
> ---
>  drivers/media/v4l2-core/v4l2-ctrls.c | 267 ++++++++++++++++++++++-------------
>  include/media/v4l2-ctrls.h           |  21 +++
>  2 files changed, 190 insertions(+), 98 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 5d1eeea..fa737a5 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -1132,6 +1132,149 @@ static void send_event(struct v4l2_fh *fh, struct v4l2_ctrl *ctrl, u32 changes)
>  			v4l2_event_queue_fh(sev->fh, &ev);
>  }
>  
> +static bool std_equal(const struct v4l2_ctrl *ctrl,
> +		      union v4l2_ctrl_ptr ptr1,
> +		      union v4l2_ctrl_ptr ptr2)
> +{
> +	switch (ctrl->type) {
> +	case V4L2_CTRL_TYPE_BUTTON:
> +		return false;
> +	case V4L2_CTRL_TYPE_STRING:
> +		/* strings are always 0-terminated */
> +		return !strcmp(ptr1.p_char, ptr2.p_char);
> +	case V4L2_CTRL_TYPE_INTEGER64:
> +		return *ptr1.p_s64 == *ptr2.p_s64;
> +	default:
> +		if (ctrl->is_ptr)
> +			return !memcmp(ptr1.p, ptr2.p, ctrl->elem_size);
> +		return *ptr1.p_s32 == *ptr2.p_s32;
> +	}
> +}
> +
> +static void std_init(const struct v4l2_ctrl *ctrl,
> +		     union v4l2_ctrl_ptr ptr)
> +{
> +	switch (ctrl->type) {
> +	case V4L2_CTRL_TYPE_STRING:
> +		memset(ptr.p_char, ' ', ctrl->minimum);
> +		ptr.p_char[ctrl->minimum] = '\0';
> +		break;
> +	case V4L2_CTRL_TYPE_INTEGER64:
> +		*ptr.p_s64 = ctrl->default_value;
> +		break;
> +	case V4L2_CTRL_TYPE_INTEGER:
> +	case V4L2_CTRL_TYPE_INTEGER_MENU:
> +	case V4L2_CTRL_TYPE_MENU:
> +	case V4L2_CTRL_TYPE_BITMASK:
> +	case V4L2_CTRL_TYPE_BOOLEAN:
> +		*ptr.p_s32 = ctrl->default_value;
> +		break;
> +	default:
> +		break;
> +	}
> +}
> +
> +static void std_log(const struct v4l2_ctrl *ctrl)
> +{
> +	union v4l2_ctrl_ptr ptr = ctrl->stores[0];
> +
> +	switch (ctrl->type) {
> +	case V4L2_CTRL_TYPE_INTEGER:
> +		pr_cont("%d", *ptr.p_s32);
> +		break;
> +	case V4L2_CTRL_TYPE_BOOLEAN:
> +		pr_cont("%s", *ptr.p_s32 ? "true" : "false");
> +		break;
> +	case V4L2_CTRL_TYPE_MENU:
> +		pr_cont("%s", ctrl->qmenu[*ptr.p_s32]);
> +		break;
> +	case V4L2_CTRL_TYPE_INTEGER_MENU:
> +		pr_cont("%lld", ctrl->qmenu_int[*ptr.p_s32]);
> +		break;
> +	case V4L2_CTRL_TYPE_BITMASK:
> +		pr_cont("0x%08x", *ptr.p_s32);
> +		break;
> +	case V4L2_CTRL_TYPE_INTEGER64:
> +		pr_cont("%lld", *ptr.p_s64);
> +		break;
> +	case V4L2_CTRL_TYPE_STRING:
> +		pr_cont("%s", ptr.p_char);
> +		break;
> +	default:
> +		pr_cont("unknown type %d", ctrl->type);
> +		break;
> +	}
> +}
> +
> +/* Round towards the closest legal value */
> +#define ROUND_TO_RANGE(val, offset_type, ctrl)			\
> +({								\
> +	offset_type offset;					\
> +	val += (ctrl)->step / 2;				\
> +	val = clamp_t(typeof(val), val,				\
> +		      (ctrl)->minimum, (ctrl)->maximum);	\
> +	offset = (val) - (ctrl)->minimum;			\
> +	offset = (ctrl)->step * (offset / (ctrl)->step);	\
> +	val = (ctrl)->minimum + offset;				\
> +	0;							\
> +})
> +
> +/* Validate a new control */
> +static int std_validate(const struct v4l2_ctrl *ctrl,
> +			union v4l2_ctrl_ptr ptr)
> +{
> +	size_t len;
> +
> +	switch (ctrl->type) {
> +	case V4L2_CTRL_TYPE_INTEGER:
> +		return ROUND_TO_RANGE(*ptr.p_s32, u32, ctrl);
> +	case V4L2_CTRL_TYPE_INTEGER64:
> +		return ROUND_TO_RANGE(*ptr.p_s64, u64, ctrl);
> +
> +	case V4L2_CTRL_TYPE_BOOLEAN:
> +		*ptr.p_s32 = !!*ptr.p_s32;
> +		return 0;
> +
> +	case V4L2_CTRL_TYPE_MENU:
> +	case V4L2_CTRL_TYPE_INTEGER_MENU:
> +		if (*ptr.p_s32 < ctrl->minimum || *ptr.p_s32 > ctrl->maximum)
> +			return -ERANGE;
> +		if (ctrl->menu_skip_mask & (1 << *ptr.p_s32))
> +			return -EINVAL;
> +		if (ctrl->type == V4L2_CTRL_TYPE_MENU &&
> +		    ctrl->qmenu[*ptr.p_s32][0] == '\0')
> +			return -EINVAL;
> +		return 0;
> +
> +	case V4L2_CTRL_TYPE_BITMASK:
> +		*ptr.p_s32 &= ctrl->maximum;
> +		return 0;
> +
> +	case V4L2_CTRL_TYPE_BUTTON:
> +	case V4L2_CTRL_TYPE_CTRL_CLASS:
> +		*ptr.p_s32 = 0;
> +		return 0;
> +
> +	case V4L2_CTRL_TYPE_STRING:
> +		len = strlen(ptr.p_char);
> +		if (len < ctrl->minimum)
> +			return -ERANGE;
> +		if ((len - ctrl->minimum) % ctrl->step)
> +			return -ERANGE;
> +		return 0;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static const struct v4l2_ctrl_type_ops std_type_ops = {
> +	.equal = std_equal,
> +	.init = std_init,
> +	.log = std_log,
> +	.validate = std_validate,
> +};
> +
>  /* Helper function: copy the current control value back to the caller */
>  static int cur_to_user(struct v4l2_ext_control *c,
>  		       struct v4l2_ctrl *ctrl)
> @@ -1315,21 +1458,7 @@ static int cluster_changed(struct v4l2_ctrl *master)
>  
>  		if (ctrl == NULL)
>  			continue;
> -		switch (ctrl->type) {
> -		case V4L2_CTRL_TYPE_BUTTON:
> -			/* Button controls are always 'different' */
> -			return 1;
> -		case V4L2_CTRL_TYPE_STRING:
> -			/* strings are always 0-terminated */
> -			diff = strcmp(ctrl->string, ctrl->cur.string);
> -			break;
> -		case V4L2_CTRL_TYPE_INTEGER64:
> -			diff = ctrl->val64 != ctrl->cur.val64;
> -			break;
> -		default:
> -			diff = ctrl->val != ctrl->cur.val;
> -			break;
> -		}
> +		diff = !ctrl->type_ops->equal(ctrl, ctrl->stores[0], ctrl->new);
>  	}
>  	return diff;
>  }
> @@ -1370,65 +1499,30 @@ static int check_range(enum v4l2_ctrl_type type,
>  	}
>  }
>  
> -/* Round towards the closest legal value */
> -#define ROUND_TO_RANGE(val, offset_type, ctrl)			\
> -({								\
> -	offset_type offset;					\
> -	val += (ctrl)->step / 2;				\
> -	val = clamp_t(typeof(val), val,				\
> -		      (ctrl)->minimum, (ctrl)->maximum);	\
> -	offset = (val) - (ctrl)->minimum;			\
> -	offset = (ctrl)->step * (offset / (ctrl)->step);	\
> -	val = (ctrl)->minimum + offset;				\
> -	0;							\
> -})
> -
>  /* Validate a new control */
>  static int validate_new(const struct v4l2_ctrl *ctrl,
>  			struct v4l2_ext_control *c)
>  {
> -	size_t len;
> +	union v4l2_ctrl_ptr ptr;
>  
>  	switch (ctrl->type) {
>  	case V4L2_CTRL_TYPE_INTEGER:
> -		return ROUND_TO_RANGE(*(s32 *)&c->value, u32, ctrl);
> -	case V4L2_CTRL_TYPE_INTEGER64:
> -		return ROUND_TO_RANGE(*(s64 *)&c->value64, u64, ctrl);
> -
> -	case V4L2_CTRL_TYPE_BOOLEAN:
> -		c->value = !!c->value;
> -		return 0;
> -
> -	case V4L2_CTRL_TYPE_MENU:
>  	case V4L2_CTRL_TYPE_INTEGER_MENU:
> -		if (c->value < ctrl->minimum || c->value > ctrl->maximum)
> -			return -ERANGE;
> -		if (ctrl->menu_skip_mask & (1 << c->value))
> -			return -EINVAL;
> -		if (ctrl->type == V4L2_CTRL_TYPE_MENU &&
> -		    ctrl->qmenu[c->value][0] == '\0')
> -			return -EINVAL;
> -		return 0;
> -
> +	case V4L2_CTRL_TYPE_MENU:
>  	case V4L2_CTRL_TYPE_BITMASK:
> -		c->value &= ctrl->maximum;
> -		return 0;
> -
> +	case V4L2_CTRL_TYPE_BOOLEAN:
>  	case V4L2_CTRL_TYPE_BUTTON:
>  	case V4L2_CTRL_TYPE_CTRL_CLASS:
> -		c->value = 0;
> -		return 0;
> +		ptr.p_s32 = &c->value;
> +		return ctrl->type_ops->validate(ctrl, ptr);
>  
> -	case V4L2_CTRL_TYPE_STRING:
> -		len = strlen(c->string);
> -		if (len < ctrl->minimum)
> -			return -ERANGE;
> -		if ((len - ctrl->minimum) % ctrl->step)
> -			return -ERANGE;
> -		return 0;
> +	case V4L2_CTRL_TYPE_INTEGER64:
> +		ptr.p_s64 = &c->value64;
> +		return ctrl->type_ops->validate(ctrl, ptr);
>  
>  	default:
> -		return -EINVAL;
> +		ptr.p = c->p;
> +		return ctrl->type_ops->validate(ctrl, ptr);
>  	}
>  }
>  
> @@ -1645,6 +1739,7 @@ unlock:
>  /* Add a new control */
>  static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  			const struct v4l2_ctrl_ops *ops,
> +			const struct v4l2_ctrl_type_ops *type_ops,
>  			u32 id, const char *name, const char *unit,
>  			enum v4l2_ctrl_type type,
>  			s64 min, s64 max, u64 step, s64 def,
> @@ -1656,6 +1751,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	unsigned sz_extra;
>  	void *data;
>  	int err;
> +	int s;
>  
>  	if (hdl->error)
>  		return NULL;
> @@ -1706,6 +1802,7 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	INIT_LIST_HEAD(&ctrl->ev_subs);
>  	ctrl->handler = hdl;
>  	ctrl->ops = ops;
> +	ctrl->type_ops = type_ops ? type_ops : &std_type_ops;
>  	ctrl->id = id;
>  	ctrl->name = name;
>  	ctrl->unit = unit;
> @@ -1727,19 +1824,16 @@ static struct v4l2_ctrl *v4l2_ctrl_new(struct v4l2_ctrl_handler *hdl,
>  	ctrl->cur.val = ctrl->val = def;
>  	data = &ctrl->stores[1];
>  
> -	if (ctrl->is_string) {
> -		ctrl->string = ctrl->new.p_char = data;
> -		ctrl->stores[0].p_char = data + elem_size;
> -
> -		if (ctrl->minimum)
> -			memset(ctrl->cur.string, ' ', ctrl->minimum);
> -	} else if (ctrl->is_ptr) {
> +	if (ctrl->is_ptr) {
>  		ctrl->p = ctrl->new.p = data;
>  		ctrl->stores[0].p = data + elem_size;
>  	} else {
>  		ctrl->new.p = &ctrl->val;
>  		ctrl->stores[0].p = &ctrl->cur.val;
>  	}
> +	for (s = -1; s <= 0; s++)
> +		ctrl->type_ops->init(ctrl, ctrl->stores[s]);
> +
>  	if (handler_new_ref(hdl, ctrl)) {
>  		kfree(ctrl);
>  		return NULL;
> @@ -1784,7 +1878,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_custom(struct v4l2_ctrl_handler *hdl,
>  		return NULL;
>  	}
>  
> -	ctrl = v4l2_ctrl_new(hdl, cfg->ops, cfg->id, name, unit,
> +	ctrl = v4l2_ctrl_new(hdl, cfg->ops, cfg->type_ops, cfg->id, name, unit,
>  			type, min, max,
>  			is_menu ? cfg->menu_skip_mask : step,
>  			def, cfg->elem_size,
> @@ -1812,7 +1906,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std(struct v4l2_ctrl_handler *hdl,
>  		handler_set_err(hdl, -EINVAL);
>  		return NULL;
>  	}
> -	return v4l2_ctrl_new(hdl, ops, id, name, unit, type,
> +	return v4l2_ctrl_new(hdl, ops, NULL, id, name, unit, type,
>  			     min, max, step, def, 0,
>  			     flags, NULL, NULL, NULL);
>  }
> @@ -1846,7 +1940,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
>  		handler_set_err(hdl, -EINVAL);
>  		return NULL;
>  	}
> -	return v4l2_ctrl_new(hdl, ops, id, name, unit, type,
> +	return v4l2_ctrl_new(hdl, ops, NULL, id, name, unit, type,
>  			     0, max, mask, def, 0,
>  			     flags, qmenu, qmenu_int, NULL);
>  }
> @@ -1879,7 +1973,8 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
>  		handler_set_err(hdl, -EINVAL);
>  		return NULL;
>  	}
> -	return v4l2_ctrl_new(hdl, ops, id, name, unit, type, 0, max, mask, def,
> +	return v4l2_ctrl_new(hdl, ops, NULL, id, name, unit, type,
> +			     0, max, mask, def,
>  			     0, flags, qmenu, NULL, NULL);
>  
>  }
> @@ -1904,7 +1999,7 @@ struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
>  		handler_set_err(hdl, -EINVAL);
>  		return NULL;
>  	}
> -	return v4l2_ctrl_new(hdl, ops, id, name, unit, type,
> +	return v4l2_ctrl_new(hdl, ops, NULL, id, name, unit, type,
>  			     0, max, 0, def, 0,
>  			     flags, NULL, qmenu_int, NULL);
>  }
> @@ -2087,32 +2182,8 @@ static void log_ctrl(const struct v4l2_ctrl *ctrl,
>  
>  	pr_info("%s%s%s: ", prefix, colon, ctrl->name);
>  
> -	switch (ctrl->type) {
> -	case V4L2_CTRL_TYPE_INTEGER:
> -		pr_cont("%d", ctrl->cur.val);
> -		break;
> -	case V4L2_CTRL_TYPE_BOOLEAN:
> -		pr_cont("%s", ctrl->cur.val ? "true" : "false");
> -		break;
> -	case V4L2_CTRL_TYPE_MENU:
> -		pr_cont("%s", ctrl->qmenu[ctrl->cur.val]);
> -		break;
> -	case V4L2_CTRL_TYPE_INTEGER_MENU:
> -		pr_cont("%lld", ctrl->qmenu_int[ctrl->cur.val]);
> -		break;
> -	case V4L2_CTRL_TYPE_BITMASK:
> -		pr_cont("0x%08x", ctrl->cur.val);
> -		break;
> -	case V4L2_CTRL_TYPE_INTEGER64:
> -		pr_cont("%lld", ctrl->cur.val64);
> -		break;
> -	case V4L2_CTRL_TYPE_STRING:
> -		pr_cont("%s", ctrl->cur.string);
> -		break;
> -	default:
> -		pr_cont("unknown type %d", ctrl->type);
> -		break;
> -	}
> +	ctrl->type_ops->log(ctrl);
> +
>  	if (ctrl->flags & (V4L2_CTRL_FLAG_INACTIVE |
>  			   V4L2_CTRL_FLAG_GRABBED |
>  			   V4L2_CTRL_FLAG_VOLATILE)) {
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 515c1ba..aaf7333 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -67,6 +67,23 @@ struct v4l2_ctrl_ops {
>  	int (*s_ctrl)(struct v4l2_ctrl *ctrl);
>  };
>  
> +/** struct v4l2_ctrl_type_ops - The control type operations that the driver has to provide.
> +  * @equal: return true if both values are equal.
> +  * @init: initialize the value.
> +  * @log: log the value.
> +  * @validate: validate the value. Return 0 on success and a negative value otherwise.
> +  */
> +struct v4l2_ctrl_type_ops {
> +	bool (*equal)(const struct v4l2_ctrl *ctrl,
> +		      union v4l2_ctrl_ptr ptr1,
> +		      union v4l2_ctrl_ptr ptr2);
> +	void (*init)(const struct v4l2_ctrl *ctrl,
> +		     union v4l2_ctrl_ptr ptr);
> +	void (*log)(const struct v4l2_ctrl *ctrl);
> +	int (*validate)(const struct v4l2_ctrl *ctrl,
> +			union v4l2_ctrl_ptr ptr);
> +};
> +
>  typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
>  
>  /** struct v4l2_ctrl - The control structure.
> @@ -102,6 +119,7 @@ typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv);
>    *		value, then the whole cluster is in manual mode. Drivers should
>    *		never set this flag directly.
>    * @ops:	The control ops.
> +  * @type_ops:	The control type ops.
>    * @id:	The control ID.
>    * @name:	The control name.
>    * @unit:	The control's unit. May be NULL.
> @@ -151,6 +169,7 @@ struct v4l2_ctrl {
>  	unsigned int manual_mode_value:8;
>  
>  	const struct v4l2_ctrl_ops *ops;
> +	const struct v4l2_ctrl_type_ops *type_ops;
>  	u32 id;
>  	const char *name;
>  	const char *unit;
> @@ -234,6 +253,7 @@ struct v4l2_ctrl_handler {
>  
>  /** struct v4l2_ctrl_config - Control configuration structure.
>    * @ops:	The control ops.
> +  * @type_ops:	The control type ops. Only needed for complex controls.
>    * @id:	The control ID.
>    * @name:	The control name.
>    * @unit:	The control's unit.
> @@ -259,6 +279,7 @@ struct v4l2_ctrl_handler {
>    */
>  struct v4l2_ctrl_config {
>  	const struct v4l2_ctrl_ops *ops;
> +	const struct v4l2_ctrl_type_ops *type_ops;
>  	u32 id;
>  	const char *name;
>  	const char *unit;


-- 

Regards,
Mauro