[PATCH] media: v4l2-ctrl: add a helper fucntion to modify the menu

[PATCH] media: v4l2-ctrl: add a helper fucntion to modify the menu

[Prabhakar Lad]

From: Lad, Prabhakar <prabhakar.lad@ti.com>

Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Rob Landley <rob@landley.net>
---
 Documentation/video4linux/v4l2-controls.txt |   26 +++++++++++++++++++++++++
 drivers/media/v4l2-core/v4l2-ctrls.c        |   28 +++++++++++++++++++++++++++
 include/media/v4l2-ctrls.h                  |   14 +++++++++++++
 3 files changed, 68 insertions(+), 0 deletions(-)

diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 43da22b..54a9539 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -196,6 +196,32 @@ the error code at the end. Saves a lot of repetitive error checking.
 It is recommended to add controls in ascending control ID order: it will be
 a bit faster that way.
 
+2.1) Changing the menu of a standard control:
+There are suitations when the control is standard but the menu items may be
+device specific, in such cases the framework provides the helper to do that.
+
+struct v4l2_ctrl * v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
+	const char * const *qmenu, s32 min, s32 max,
+	u32 menu_skip_mask, s32 def);
+
+This helper, function is used to modify the menu, min, max, mask and
+the default value to set.
+Example for usage:
+	static const char * const test_pattern[] = {
+		"Disabled",
+		"Vertical Bars",
+		"Vertical Bars",
+		"Solid Black",
+		"Solid White",
+		NULL
+	};
+	struct v4l2_ctrl *test_pattern_ctrl =
+		v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
+			V4L2_CID_TEST_PATTERN, V4L2_TEST_PATTERN_DISABLED, 0,
+			V4L2_TEST_PATTERN_DISABLED);
+
+	v4l2_ctrl_modify_menu(test_pattern_ctrl, test_pattern, 0, 5, 0x3, 0);
+
 3) Optionally force initial control setup:
 
 	v4l2_ctrl_handler_setup(&foo->ctrl_handler);
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index d731422..ac0fb28 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2666,3 +2666,31 @@ unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
 	return 0;
 }
 EXPORT_SYMBOL(v4l2_ctrl_poll);
+
+/* Helper function for standard menu controls to modify the menu */
+struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
+					 const char * const *qmenu, s32 min,
+					 s32 max, u32 menu_skip_mask, s32 def)
+{
+	if (ctrl->type != V4L2_CTRL_TYPE_MENU)
+		return NULL;
+
+	if (qmenu == NULL)
+		return NULL;
+
+	/* Determine if it is standard menu control */
+	if (!v4l2_ctrl_get_menu(ctrl->id))
+		return NULL;
+
+	if ((def > max) || (max < min))
+		return NULL;
+
+	ctrl->qmenu = qmenu;
+	ctrl->minimum = min;
+	ctrl->maximum = max;
+	ctrl->menu_skip_mask = menu_skip_mask;
+	ctrl->cur.val = ctrl->val = ctrl->default_value = def;
+
+	return ctrl;
+}
+EXPORT_SYMBOL(v4l2_ctrl_modify_menu);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 776605f..5b0ea04 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -488,6 +488,20 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
 	mutex_unlock(ctrl->handler->lock);
 }
 
+/**
+ * v4l2_ctrl_modify_menu() - Modify the menu. This function is used when the
+ * control is standard but the menu is specific to device.
+ * @ctrl:		The control to change the menu.
+ * @qmenu:		The menu to which control will point to.
+ * @min:		Minimum value of the control.
+ * @max:		Maximum valur of the control.
+ * @menu_skip_mask:	The control's skip mask for menu controls.
+ * @def:		The default value for control.
+ */
+struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
+					 const char * const *qmenu, s32 min,
+					 s32 max, u32 menu_skip_mask, s32 def);
+
 /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
   * @ctrl:	The control.
   *
-- 
1.7.0.4

Re: [PATCH] media: v4l2-ctrl: add a helper fucntion to modify the menu

[Hans Verkuil]

On Mon September 10 2012 13:57:36 Prabhakar Lad wrote:
> From: Lad, Prabhakar <prabhakar.lad@ti.com>
> 
> Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
> Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
> Cc: Hans Verkuil <hans.verkuil@cisco.com>
> Cc: Sakari Ailus <sakari.ailus@iki.fi>
> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
> Cc: Hans de Goede <hdegoede@redhat.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: Rob Landley <rob@landley.net>
> ---
>  Documentation/video4linux/v4l2-controls.txt |   26 +++++++++++++++++++++++++
>  drivers/media/v4l2-core/v4l2-ctrls.c        |   28 +++++++++++++++++++++++++++
>  include/media/v4l2-ctrls.h                  |   14 +++++++++++++
>  3 files changed, 68 insertions(+), 0 deletions(-)
> 
> diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
> index 43da22b..54a9539 100644
> --- a/Documentation/video4linux/v4l2-controls.txt
> +++ b/Documentation/video4linux/v4l2-controls.txt
> @@ -196,6 +196,32 @@ the error code at the end. Saves a lot of repetitive error checking.
>  It is recommended to add controls in ascending control ID order: it will be
>  a bit faster that way.
>  
> +2.1) Changing the menu of a standard control:
> +There are suitations when the control is standard but the menu items may be
> +device specific, in such cases the framework provides the helper to do that.

The "Menu Controls" section in this file would be a better place to add this.

> +
> +struct v4l2_ctrl * v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
> +	const char * const *qmenu, s32 min, s32 max,
> +	u32 menu_skip_mask, s32 def);
> +
> +This helper, function is used to modify the menu, min, max, mask and
> +the default value to set.
> +Example for usage:
> +	static const char * const test_pattern[] = {
> +		"Disabled",
> +		"Vertical Bars",
> +		"Vertical Bars",
> +		"Solid Black",
> +		"Solid White",
> +		NULL
> +	};
> +	struct v4l2_ctrl *test_pattern_ctrl =
> +		v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
> +			V4L2_CID_TEST_PATTERN, V4L2_TEST_PATTERN_DISABLED, 0,
> +			V4L2_TEST_PATTERN_DISABLED);
> +
> +	v4l2_ctrl_modify_menu(test_pattern_ctrl, test_pattern, 0, 5, 0x3, 0);
> +
>  3) Optionally force initial control setup:
>  
>  	v4l2_ctrl_handler_setup(&foo->ctrl_handler);
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index d731422..ac0fb28 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -2666,3 +2666,31 @@ unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
>  	return 0;
>  }
>  EXPORT_SYMBOL(v4l2_ctrl_poll);
> +
> +/* Helper function for standard menu controls to modify the menu */
> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
> +					 const char * const *qmenu, s32 min,

The minimum is always 0 for menu controls, so this argument should be
removed. It's not part of v4l2_ctrl_new_std_menu either.

There is no need to return the pointer here, so just set the return to void.

> +					 s32 max, u32 menu_skip_mask, s32 def)
> +{
> +	if (ctrl->type != V4L2_CTRL_TYPE_MENU)
> +		return NULL;
> +
> +	if (qmenu == NULL)
> +		return NULL;

Change this to:

	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_MENU || qmenu == NULL))
		return;

> +
> +	/* Determine if it is standard menu control */
> +	if (!v4l2_ctrl_get_menu(ctrl->id))
> +		return NULL;

This test can be removed. Why should we prohibit calling this function for
non-standard controls?

> +
> +	if ((def > max) || (max < min))
> +		return NULL;

Also replace with if (WARN_ON(def < 0 || def > max)).

All these errors are driver errors and so should just report it in the kernel
log and then bail out.

> +
> +	ctrl->qmenu = qmenu;
> +	ctrl->minimum = min;

No need to set minimum. It's already 0.

> +	ctrl->maximum = max;
> +	ctrl->menu_skip_mask = menu_skip_mask;
> +	ctrl->cur.val = ctrl->val = ctrl->default_value = def;
> +
> +	return ctrl;
> +}
> +EXPORT_SYMBOL(v4l2_ctrl_modify_menu);
> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> index 776605f..5b0ea04 100644
> --- a/include/media/v4l2-ctrls.h
> +++ b/include/media/v4l2-ctrls.h
> @@ -488,6 +488,20 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
>  	mutex_unlock(ctrl->handler->lock);
>  }
>  
> +/**
> + * v4l2_ctrl_modify_menu() - Modify the menu. This function is used when the
> + * control is standard but the menu is specific to device.
> + * @ctrl:		The control to change the menu.
> + * @qmenu:		The menu to which control will point to.
> + * @min:		Minimum value of the control.
> + * @max:		Maximum valur of the control.
> + * @menu_skip_mask:	The control's skip mask for menu controls.
> + * @def:		The default value for control.
> + */
> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
> +					 const char * const *qmenu, s32 min,
> +					 s32 max, u32 menu_skip_mask, s32 def);
> +
>  /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
>    * @ctrl:	The control.
>    *
> 

Regards,

	Hans

Re: [PATCH] media: v4l2-ctrl: add a helper fucntion to modify the menu

[Manjunath Hadli]

Hi Hans,

Thanks for the review.

On Monday 10 September 2012 05:43 PM, Hans Verkuil wrote:
> On Mon September 10 2012 13:57:36 Prabhakar Lad wrote:
>> From: Lad, Prabhakar <prabhakar.lad@ti.com>
>>
>> Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
>> Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
>> Cc: Hans Verkuil <hans.verkuil@cisco.com>
>> Cc: Sakari Ailus <sakari.ailus@iki.fi>
>> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
>> Cc: Hans de Goede <hdegoede@redhat.com>
>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>> Cc: Rob Landley <rob@landley.net>
>> ---
>>  Documentation/video4linux/v4l2-controls.txt |   26 +++++++++++++++++++++++++
>>  drivers/media/v4l2-core/v4l2-ctrls.c        |   28 +++++++++++++++++++++++++++
>>  include/media/v4l2-ctrls.h                  |   14 +++++++++++++
>>  3 files changed, 68 insertions(+), 0 deletions(-)
>>
>> diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
>> index 43da22b..54a9539 100644
>> --- a/Documentation/video4linux/v4l2-controls.txt
>> +++ b/Documentation/video4linux/v4l2-controls.txt
>> @@ -196,6 +196,32 @@ the error code at the end. Saves a lot of repetitive error checking.
>>  It is recommended to add controls in ascending control ID order: it will be
>>  a bit faster that way.
>>  
>> +2.1) Changing the menu of a standard control:
>> +There are suitations when the control is standard but the menu items may be
>> +device specific, in such cases the framework provides the helper to do that.
> 
> The "Menu Controls" section in this file would be a better place to add this.
> 
Ok.

>> +
>> +struct v4l2_ctrl * v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>> +	const char * const *qmenu, s32 min, s32 max,
>> +	u32 menu_skip_mask, s32 def);
>> +
>> +This helper, function is used to modify the menu, min, max, mask and
>> +the default value to set.
>> +Example for usage:
>> +	static const char * const test_pattern[] = {
>> +		"Disabled",
>> +		"Vertical Bars",
>> +		"Vertical Bars",
>> +		"Solid Black",
>> +		"Solid White",
>> +		NULL
>> +	};
>> +	struct v4l2_ctrl *test_pattern_ctrl =
>> +		v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
>> +			V4L2_CID_TEST_PATTERN, V4L2_TEST_PATTERN_DISABLED, 0,
>> +			V4L2_TEST_PATTERN_DISABLED);
>> +
>> +	v4l2_ctrl_modify_menu(test_pattern_ctrl, test_pattern, 0, 5, 0x3, 0);
>> +
>>  3) Optionally force initial control setup:
>>  
>>  	v4l2_ctrl_handler_setup(&foo->ctrl_handler);
>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>> index d731422..ac0fb28 100644
>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>> @@ -2666,3 +2666,31 @@ unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
>>  	return 0;
>>  }
>>  EXPORT_SYMBOL(v4l2_ctrl_poll);
>> +
>> +/* Helper function for standard menu controls to modify the menu */
>> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>> +					 const char * const *qmenu, s32 min,
> 
> The minimum is always 0 for menu controls, so this argument should be
> removed. It's not part of v4l2_ctrl_new_std_menu either.
> 
> There is no need to return the pointer here, so just set the return to void.
> 
Ok.

>> +					 s32 max, u32 menu_skip_mask, s32 def)
>> +{
>> +	if (ctrl->type != V4L2_CTRL_TYPE_MENU)
>> +		return NULL;
>> +
>> +	if (qmenu == NULL)
>> +		return NULL;
> 
> Change this to:
> 
> 	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_MENU || qmenu == NULL))
> 		return;
> 
Ok.

>> +
>> +	/* Determine if it is standard menu control */
>> +	if (!v4l2_ctrl_get_menu(ctrl->id))
>> +		return NULL;
> 
> This test can be removed. Why should we prohibit calling this function for
> non-standard controls?
> 
Any how how if its custom control, the menu will be provided by user
itself, so why would he fell the necessity of this function ? But
providing an option wont harm I'll remove it.

>> +
>> +	if ((def > max) || (max < min))
>> +		return NULL;
> 
> Also replace with if (WARN_ON(def < 0 || def > max)).
> 
> All these errors are driver errors and so should just report it in the kernel
> log and then bail out.
>
Ok.

>> +
>> +	ctrl->qmenu = qmenu;
>> +	ctrl->minimum = min;
> 
> No need to set minimum. It's already 0.
> 
Ok.

Regards,
--Prabhakar Lad

>> +	ctrl->maximum = max;
>> +	ctrl->menu_skip_mask = menu_skip_mask;
>> +	ctrl->cur.val = ctrl->val = ctrl->default_value = def;
>> +
>> +	return ctrl;
>> +}
>> +EXPORT_SYMBOL(v4l2_ctrl_modify_menu);
>> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
>> index 776605f..5b0ea04 100644
>> --- a/include/media/v4l2-ctrls.h
>> +++ b/include/media/v4l2-ctrls.h
>> @@ -488,6 +488,20 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
>>  	mutex_unlock(ctrl->handler->lock);
>>  }
>>  
>> +/**
>> + * v4l2_ctrl_modify_menu() - Modify the menu. This function is used when the
>> + * control is standard but the menu is specific to device.
>> + * @ctrl:		The control to change the menu.
>> + * @qmenu:		The menu to which control will point to.
>> + * @min:		Minimum value of the control.
>> + * @max:		Maximum valur of the control.
>> + * @menu_skip_mask:	The control's skip mask for menu controls.
>> + * @def:		The default value for control.
>> + */
>> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>> +					 const char * const *qmenu, s32 min,
>> +					 s32 max, u32 menu_skip_mask, s32 def);
>> +
>>  /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
>>    * @ctrl:	The control.
>>    *
>>
> 
> Regards,
> 
> 	Hans
> 

Re: [PATCH] media: v4l2-ctrl: add a helper fucntion to modify the menu

[Prabhakar Lad]

On Monday 10 September 2012 06:06 PM, Manjunath Hadli wrote:
> Hi Hans,
> 
> Thanks for the review.
> 
> On Monday 10 September 2012 05:43 PM, Hans Verkuil wrote:
>> On Mon September 10 2012 13:57:36 Prabhakar Lad wrote:
>>> From: Lad, Prabhakar <prabhakar.lad@ti.com>
>>>
>>> Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
>>> Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
>>> Cc: Hans Verkuil <hans.verkuil@cisco.com>
>>> Cc: Sakari Ailus <sakari.ailus@iki.fi>
>>> Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
>>> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>>> Cc: Mauro Carvalho Chehab <mchehab@infradead.org>
>>> Cc: Hans de Goede <hdegoede@redhat.com>
>>> Cc: Kyungmin Park <kyungmin.park@samsung.com>
>>> Cc: Rob Landley <rob@landley.net>
>>> ---
>>>  Documentation/video4linux/v4l2-controls.txt |   26 +++++++++++++++++++++++++
>>>  drivers/media/v4l2-core/v4l2-ctrls.c        |   28 +++++++++++++++++++++++++++
>>>  include/media/v4l2-ctrls.h                  |   14 +++++++++++++
>>>  3 files changed, 68 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
>>> index 43da22b..54a9539 100644
>>> --- a/Documentation/video4linux/v4l2-controls.txt
>>> +++ b/Documentation/video4linux/v4l2-controls.txt
>>> @@ -196,6 +196,32 @@ the error code at the end. Saves a lot of repetitive error checking.
>>>  It is recommended to add controls in ascending control ID order: it will be
>>>  a bit faster that way.
>>>  
>>> +2.1) Changing the menu of a standard control:
>>> +There are suitations when the control is standard but the menu items may be
>>> +device specific, in such cases the framework provides the helper to do that.
>>
>> The "Menu Controls" section in this file would be a better place to add this.
>>
> Ok.
> 
>>> +
>>> +struct v4l2_ctrl * v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>>> +	const char * const *qmenu, s32 min, s32 max,
>>> +	u32 menu_skip_mask, s32 def);
>>> +
>>> +This helper, function is used to modify the menu, min, max, mask and
>>> +the default value to set.
>>> +Example for usage:
>>> +	static const char * const test_pattern[] = {
>>> +		"Disabled",
>>> +		"Vertical Bars",
>>> +		"Vertical Bars",
>>> +		"Solid Black",
>>> +		"Solid White",
>>> +		NULL
>>> +	};
>>> +	struct v4l2_ctrl *test_pattern_ctrl =
>>> +		v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
>>> +			V4L2_CID_TEST_PATTERN, V4L2_TEST_PATTERN_DISABLED, 0,
>>> +			V4L2_TEST_PATTERN_DISABLED);
>>> +
>>> +	v4l2_ctrl_modify_menu(test_pattern_ctrl, test_pattern, 0, 5, 0x3, 0);
>>> +
>>>  3) Optionally force initial control setup:
>>>  
>>>  	v4l2_ctrl_handler_setup(&foo->ctrl_handler);
>>> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
>>> index d731422..ac0fb28 100644
>>> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
>>> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
>>> @@ -2666,3 +2666,31 @@ unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
>>>  	return 0;
>>>  }
>>>  EXPORT_SYMBOL(v4l2_ctrl_poll);
>>> +
>>> +/* Helper function for standard menu controls to modify the menu */
>>> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>>> +					 const char * const *qmenu, s32 min,
>>
>> The minimum is always 0 for menu controls, so this argument should be
>> removed. It's not part of v4l2_ctrl_new_std_menu either.
>>
>> There is no need to return the pointer here, so just set the return to void.
>>
> Ok.
> 
>>> +					 s32 max, u32 menu_skip_mask, s32 def)
>>> +{
>>> +	if (ctrl->type != V4L2_CTRL_TYPE_MENU)
>>> +		return NULL;
>>> +
>>> +	if (qmenu == NULL)
>>> +		return NULL;
>>
>> Change this to:
>>
>> 	if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_MENU || qmenu == NULL))
>> 		return;
>>
> Ok.
> 
>>> +
>>> +	/* Determine if it is standard menu control */
>>> +	if (!v4l2_ctrl_get_menu(ctrl->id))
>>> +		return NULL;
>>
>> This test can be removed. Why should we prohibit calling this function for
>> non-standard controls?
>>
> Any how how if its custom control, the menu will be provided by user
> itself, so why would he fell the necessity of this function ? But
> providing an option wont harm I'll remove it.
> 
>>> +
>>> +	if ((def > max) || (max < min))
>>> +		return NULL;
>>
>> Also replace with if (WARN_ON(def < 0 || def > max)).
>>
>> All these errors are driver errors and so should just report it in the kernel
>> log and then bail out.
>>
> Ok.
> 
>>> +
>>> +	ctrl->qmenu = qmenu;
>>> +	ctrl->minimum = min;
>>
>> No need to set minimum. It's already 0.
>>
> Ok.
> 
> Regards,
> --Prabhakar Lad
> 
My Bad :(. Replied with Manju's ID.

Thanks,
--Prabhakar

>>> +	ctrl->maximum = max;
>>> +	ctrl->menu_skip_mask = menu_skip_mask;
>>> +	ctrl->cur.val = ctrl->val = ctrl->default_value = def;
>>> +
>>> +	return ctrl;
>>> +}
>>> +EXPORT_SYMBOL(v4l2_ctrl_modify_menu);
>>> diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
>>> index 776605f..5b0ea04 100644
>>> --- a/include/media/v4l2-ctrls.h
>>> +++ b/include/media/v4l2-ctrls.h
>>> @@ -488,6 +488,20 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
>>>  	mutex_unlock(ctrl->handler->lock);
>>>  }
>>>  
>>> +/**
>>> + * v4l2_ctrl_modify_menu() - Modify the menu. This function is used when the
>>> + * control is standard but the menu is specific to device.
>>> + * @ctrl:		The control to change the menu.
>>> + * @qmenu:		The menu to which control will point to.
>>> + * @min:		Minimum value of the control.
>>> + * @max:		Maximum valur of the control.
>>> + * @menu_skip_mask:	The control's skip mask for menu controls.
>>> + * @def:		The default value for control.
>>> + */
>>> +struct v4l2_ctrl *v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl,
>>> +					 const char * const *qmenu, s32 min,
>>> +					 s32 max, u32 menu_skip_mask, s32 def);
>>> +
>>>  /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
>>>    * @ctrl:	The control.
>>>    *
>>>
>>
>> Regards,
>>
>> 	Hans
>>
>