Commit 2249aa5c authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab

[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: default avatarHans Verkuil <hans.verkuil@cisco.com>
Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab@redhat.com>
parent abbec2d4
......@@ -246,7 +246,6 @@ may be NULL if the subdev driver does not support anything from that category.
It looks like this:
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);
...
......@@ -346,24 +345,24 @@ Afterwards the subdev module can be unloaded and sd->dev == NULL.
You can call an ops function either directly:
err = sd->ops->core->g_chip_ident(sd, &chip);
err = sd->ops->core->g_std(sd, &norm);
but it is better and easier to use this macro:
err = v4l2_subdev_call(sd, core, g_chip_ident, &chip);
err = v4l2_subdev_call(sd, core, g_std, &norm);
The macro will to the right NULL pointer checks and returns -ENODEV if subdev
is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_chip_ident is
NULL, or the actual result of the subdev->ops->core->g_chip_ident ops.
is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_std is
NULL, or the actual result of the subdev->ops->core->g_std ops.
It is also possible to call all or a subset of the sub-devices:
v4l2_device_call_all(v4l2_dev, 0, core, g_chip_ident, &chip);
v4l2_device_call_all(v4l2_dev, 0, core, g_std, &norm);
Any subdev that does not support this ops is skipped and error results are
ignored. If you want to check for errors use this:
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);
Any error except -ENOIOCTLCMD will exit the loop with that error. If no
errors (except -ENOIOCTLCMD) occurred, then 0 is returned.
......
......@@ -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。
......
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