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authorHans Verkuil <hans.verkuil@cisco.com>2013-05-29 12:59:57 +0200
committerMauro Carvalho Chehab <mchehab@redhat.com>2013-06-17 14:18:29 +0200
commit2249aa5c97a017be4e3b5bb0e9a3ca2d2ed31b27 (patch)
tree4e5449abaf34ece02dee15a52ca789c6f64da63f /Documentation/zh_CN/video4linux
parent[media] DocBook/media/v4l: update VIDIOC_DBG_ documentation (diff)
downloadlinux-2249aa5c97a017be4e3b5bb0e9a3ca2d2ed31b27.tar.xz
linux-2249aa5c97a017be4e3b5bb0e9a3ca2d2ed31b27.zip
[media] v4l2-framework: replace g_chip_ident by g_std in the examples
The framework documentation used the g_chip_ident op as an example. This op has been removed, so replace its use in the examples by the g_std op. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Cc: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/zh_CN/video4linux')
-rw-r--r--Documentation/zh_CN/video4linux/v4l2-framework.txt13
1 files changed, 6 insertions, 7 deletions
diff --git a/Documentation/zh_CN/video4linux/v4l2-framework.txt b/Documentation/zh_CN/video4linux/v4l2-framework.txt
index 44c1d934c4e3..0da95dbaef34 100644
--- a/Documentation/zh_CN/video4linux/v4l2-framework.txt
+++ b/Documentation/zh_CN/video4linux/v4l2-framework.txt
@@ -247,7 +247,6 @@ i2c_client 结构体,i2c_set_clientdata() 函数可用于保存一个 v4l2_sub
这些结构体定义如下:
struct v4l2_subdev_core_ops {
- int (*g_chip_ident)(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip);
int (*log_status)(struct v4l2_subdev *sd);
int (*init)(struct v4l2_subdev *sd, u32 val);
...
@@ -337,24 +336,24 @@ subdev->dev 域就指向了 v4l2_device。
注册之设备后,可通过以下方式直接调用其操作函数:
- err = sd->ops->core->g_chip_ident(sd, &chip);
+ err = sd->ops->core->g_std(sd, &norm);
但使用如下宏会比较容易且合适:
- err = v4l2_subdev_call(sd, core, g_chip_ident, &chip);
+ err = v4l2_subdev_call(sd, core, g_std, &norm);
这个宏将会做 NULL 指针检查,如果 subdev 为 NULL,则返回-ENODEV;如果
-subdev->core 或 subdev->core->g_chip_ident 为 NULL,则返回 -ENOIOCTLCMD;
-否则将返回 subdev->ops->core->g_chip_ident ops 调用的实际结果。
+subdev->core 或 subdev->core->g_std 为 NULL,则返回 -ENOIOCTLCMD;
+否则将返回 subdev->ops->core->g_std ops 调用的实际结果。
有时也可能同时调用所有或一系列子设备的某个操作函数:
- v4l2_device_call_all(v4l2_dev, 0, core, g_chip_ident, &chip);
+ v4l2_device_call_all(v4l2_dev, 0, core, g_std, &norm);
任何不支持此操作的子设备都会被跳过,并忽略错误返回值。但如果你需要
检查出错码,则可使用如下函数:
- err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_chip_ident, &chip);
+ err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_std, &norm);
除 -ENOIOCTLCMD 外的任何错误都会跳出循环并返回错误值。如果(除 -ENOIOCTLCMD
外)没有错误发生,则返回 0。