Hi Sakari,
On 22/01/2022 17:36, Sakari Ailus wrote:
> The bus_info or a similar field exists in a lot of structs, yet drivers
> tend to set the value of that field by themselves in a determinable way.
> Thus provide a helper for doing this. To be used in subsequent patches.
>
> Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> include/media/media-device.h | 30 +++++++++++++++++++++++++++---
> 1 file changed, 27 insertions(+), 3 deletions(-)
>
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index 1345e6da688a..9f0458068196 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -13,12 +13,13 @@
>
> #include <linux/list.h>
> #include <linux/mutex.h>
> +#include <linux/pci.h>
> +#include <linux/platform_device.h>
>
> #include <media/media-devnode.h>
> #include <media/media-entity.h>
>
> struct ida;
> -struct device;
> struct media_device;
>
> /**
> @@ -181,8 +182,7 @@ struct media_device {
> atomic_t request_id;
> };
>
> -/* We don't need to include pci.h or usb.h here */
> -struct pci_dev;
> +/* We don't need to include usb.h here */
> struct usb_device;
>
> #ifdef CONFIG_MEDIA_CONTROLLER
> @@ -496,4 +496,28 @@ static inline void __media_device_usb_init(struct media_device *mdev,
> #define media_device_usb_init(mdev, udev, name) \
> __media_device_usb_init(mdev, udev, name, KBUILD_MODNAME)
>
> +static inline void
> +__media_set_bus_info(char *bus_info, size_t bus_info_size, struct device *dev)
> +{
> + if (!dev || *bus_info)
> + return;
> +
> + if (dev_is_platform(dev))
> + snprintf(bus_info, bus_info_size, "platform:%s", dev_name(dev));
> + else if (dev_is_pci(dev))
> + snprintf(bus_info, bus_info_size, "PCI:%s", dev_name(dev));
> +}
> +
> +/**
> + * media_set_bus_info() - Conditionally set bus_info
> + *
> + * @bus_info: Variable where to write the bus info (char array)
> + * @dev: Related struct device
> + *
> + * Sets bus information based on device conditionally, if the first character of
> + * &bus_info is not '\0' and dev is non-NULL.
> + */
> +#define media_set_bus_info(bus_info, dev) \
> + __media_set_bus_info(bus_info, sizeof(bus_info), dev)
Wouldn't it be simpler to make two #defines:
#define media_set_bus_info(mdev, dev) \
__media_set_bus_info(mdev->bus_info, sizeof(mdev->bus_info), dev)
and:
#define v4l2_cap_set_bus_info(cap, dev) \
__media_set_bus_info(cap->bus_info, sizeof(cap->bus_info), dev)
That way the sizeof() always works correctly.
This could also be static inlines to have better type checking, of course.
Another option is:
#define media_set_bus_info(s, dev) \
__media_set_bus_info((s)->bus_info, sizeof((s)->bus_info), dev)
That's more generic, but it does make the assumption that the struct s
has a field bus_info. Which is a reasonable assumption IMHO.
I do like the idea of this series.
Regards,
Hans
> +
> #endif
