V4L/DVB (9903): uvcvideo: V4L2 zoom controls support

Add support for absolute and continuous zoom controls (mapped to absolute
and relative UVC zoom controls).

Signed-off-by: Laurent Pinchart <laurent.pinchart@skynet.be>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 71 insertions, 14 deletions

diff --git a/drivers/media/video/uvc/uvc_ctrl.c b/drivers/media/video/uvc/uvc_ctrl.c
index 335cb00e595b..2208165aa6f0 100644
--- a/drivers/media/video/uvc/uvc_ctrl.c
+++ b/drivers/media/video/uvc/uvc_ctrl.c
@@ -327,6 +327,31 @@ static struct uvc_menu_info exposure_auto_controls[] = {
         { 8, "Aperture Priority Mode" },
 };
 
+static __s32 uvc_ctrl_get_zoom(struct uvc_control_mapping *mapping,
+        __u8 query, const __u8 *data)
+{
+        __s8 zoom = (__s8)data[0];
+
+        switch (query) {
+        case GET_CUR:
+                return (zoom == 0) ? 0 : (zoom > 0 ? data[2] : -data[2]);
+
+        case GET_MIN:
+        case GET_MAX:
+        case GET_RES:
+        case GET_DEF:
+        default:
+                return data[2];
+        }
+}
+
+static void uvc_ctrl_set_zoom(struct uvc_control_mapping *mapping,
+        __s32 value, __u8 *data)
+{
+        data[0] = value == 0 ? 0 : (value > 0) ? 1 : 0xff;
+        data[2] = min(abs(value), 0xff);
+}
+
 static struct uvc_control_mapping uvc_ctrl_mappings[] = {
         {
                 .id             = V4L2_CID_BRIGHTNESS,
@@ -533,6 +558,28 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] = {
                 .data_type      = UVC_CTRL_DATA_TYPE_BOOLEAN,
         },
         {
+                .id             = V4L2_CID_ZOOM_ABSOLUTE,
+                .name           = "Zoom, Absolute",
+                .entity         = UVC_GUID_UVC_CAMERA,
+                .selector       = CT_ZOOM_ABSOLUTE_CONTROL,
+                .size           = 16,
+                .offset         = 0,
+                .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+                .data_type      = UVC_CTRL_DATA_TYPE_UNSIGNED,
+        },
+        {
+                .id             = V4L2_CID_ZOOM_CONTINUOUS,
+                .name           = "Zoom, Continuous",
+                .entity         = UVC_GUID_UVC_CAMERA,
+                .selector       = CT_ZOOM_RELATIVE_CONTROL,
+                .size           = 0,
+                .offset         = 0,
+                .v4l2_type      = V4L2_CTRL_TYPE_INTEGER,
+                .data_type      = UVC_CTRL_DATA_TYPE_SIGNED,
+                .get            = uvc_ctrl_get_zoom,
+                .set            = uvc_ctrl_set_zoom,
+        },
+        {
                 .id             = V4L2_CID_PRIVACY,
                 .name           = "Privacy",
                 .entity         = UVC_GUID_UVC_CAMERA,
@@ -568,8 +615,8 @@ static inline void uvc_clear_bit(__u8 *data, int bit)
  * a signed 32bit integer. Sign extension will be performed if the mapping
  * references a signed data type.
  */
-static __s32 uvc_get_le_value(const __u8 *data,
-        struct uvc_control_mapping *mapping)
+static __s32 uvc_get_le_value(struct uvc_control_mapping *mapping,
+        __u8 query, const __u8 *data)
 {
         int bits = mapping->size;
         int offset = mapping->offset;
@@ -598,8 +645,8 @@ static __s32 uvc_get_le_value(const __u8 *data,
 /* Set the bit string specified by mapping->offset and mapping->size
  * in the little-endian data stored at 'data' to the value 'value'.
  */
-static void uvc_set_le_value(__s32 value, __u8 *data,
-        struct uvc_control_mapping *mapping)
+static void uvc_set_le_value(struct uvc_control_mapping *mapping,
+        __s32 value, __u8 *data)
 {
         int bits = mapping->size;
         int offset = mapping->offset;
@@ -751,7 +798,7 @@ int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
                                 video->dev->intfnum, ctrl->info->selector,
                                 data, ctrl->info->size)) < 0)
                         goto out;
-                v4l2_ctrl->default_value = uvc_get_le_value(data, mapping);
+                v4l2_ctrl->default_value = mapping->get(mapping, GET_DEF, data);
         }
 
         switch (mapping->v4l2_type) {
@@ -787,21 +834,21 @@ int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
                                 video->dev->intfnum, ctrl->info->selector,
                                 data, ctrl->info->size)) < 0)
                         goto out;
-                v4l2_ctrl->minimum = uvc_get_le_value(data, mapping);
+                v4l2_ctrl->minimum = mapping->get(mapping, GET_MIN, data);
         }
         if (ctrl->info->flags & UVC_CONTROL_GET_MAX) {
                 if ((ret = uvc_query_ctrl(video->dev, GET_MAX, ctrl->entity->id,
                                 video->dev->intfnum, ctrl->info->selector,
                                 data, ctrl->info->size)) < 0)
                         goto out;
-                v4l2_ctrl->maximum = uvc_get_le_value(data, mapping);
+                v4l2_ctrl->maximum = mapping->get(mapping, GET_MAX, data);
         }
         if (ctrl->info->flags & UVC_CONTROL_GET_RES) {
                 if ((ret = uvc_query_ctrl(video->dev, GET_RES, ctrl->entity->id,
                                 video->dev->intfnum, ctrl->info->selector,
                                 data, ctrl->info->size)) < 0)
                         goto out;
-                v4l2_ctrl->step = uvc_get_le_value(data, mapping);
+                v4l2_ctrl->step = mapping->get(mapping, GET_RES, data);
         }
 
         ret = 0;
@@ -938,8 +985,8 @@ int uvc_ctrl_get(struct uvc_video_device *video,
                 ctrl->loaded = 1;
         }
 
-        xctrl->value = uvc_get_le_value(
-                uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), mapping);
+        xctrl->value = mapping->get(mapping, GET_CUR,
+                uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 
         if (mapping->v4l2_type == V4L2_CTRL_TYPE_MENU) {
                 menu = mapping->menu_info;
@@ -995,8 +1042,8 @@ int uvc_ctrl_set(struct uvc_video_device *video,
                        ctrl->info->size);
         }
 
-        uvc_set_le_value(value,
-                uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT), mapping);
+        mapping->set(mapping, value,
+                uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
 
         ctrl->dirty = 1;
         ctrl->modified = 1;
@@ -1272,6 +1319,11 @@ int uvc_ctrl_add_mapping(struct uvc_control_mapping *mapping)
         struct uvc_control_mapping *map;
         int ret = -EINVAL;
 
+        if (mapping->get == NULL)
+                mapping->get = uvc_get_le_value;
+        if (mapping->set == NULL)
+                mapping->set = uvc_set_le_value;
+
         if (mapping->id & ~V4L2_CTRL_ID_MASK) {
                 uvc_trace(UVC_TRACE_CONTROL, "Can't add mapping '%s' with "
                         "invalid control id 0x%08x\n", mapping->name,
diff --git a/drivers/media/video/uvc/uvc_v4l2.c b/drivers/media/video/uvc/uvc_v4l2.c
index 7b1c1363583c..2e1fd1b2a619 100644
--- a/drivers/media/video/uvc/uvc_v4l2.c
+++ b/drivers/media/video/uvc/uvc_v4l2.c
@@ -914,7 +914,7 @@ static int uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 if (!capable(CAP_SYS_ADMIN))
                         return -EPERM;
 
-                info = kmalloc(sizeof *info, GFP_KERNEL);
+                info = kzalloc(sizeof *info, GFP_KERNEL);
                 if (info == NULL)
                         return -ENOMEM;
 
@@ -941,7 +941,7 @@ static int uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
                 if (!capable(CAP_SYS_ADMIN))
                         return -EPERM;
 
-                map = kmalloc(sizeof *map, GFP_KERNEL);
+                map = kzalloc(sizeof *map, GFP_KERNEL);
                 if (map == NULL)
                         return -ENOMEM;
 
diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 00d593776b86..2a5bdacbaf27 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -384,6 +384,11 @@ struct uvc_control_mapping {
 
         struct uvc_menu_info *menu_info;
         __u32 menu_count;
+
+        __s32 (*get) (struct uvc_control_mapping *mapping, __u8 query,
+                      const __u8 *data);
+        void (*set) (struct uvc_control_mapping *mapping, __s32 value,
+                     __u8 *data);
 };
 
 struct uvc_control {